Don't reset ->total_link_count on nested calls of vfs_path_lookup()

[people/ms/linux.git] / drivers / gpu / drm / i915 / intel_dp.c

/*
 * Copyright © 2008 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Keith Packard <keithp@keithp.com>
 *
 */

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <drm/drmP.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_edid.h>
#include "intel_drv.h"
#include <drm/i915_drm.h>
#include "i915_drv.h"

#define DP_LINK_CHECK_TIMEOUT   (10 * 1000)

/* Compliance test status bits  */
#define INTEL_DP_RESOLUTION_SHIFT_MASK  0
#define INTEL_DP_RESOLUTION_PREFERRED   (1 << INTEL_DP_RESOLUTION_SHIFT_MASK)
#define INTEL_DP_RESOLUTION_STANDARD    (2 << INTEL_DP_RESOLUTION_SHIFT_MASK)
#define INTEL_DP_RESOLUTION_FAILSAFE    (3 << INTEL_DP_RESOLUTION_SHIFT_MASK)

struct dp_link_dpll {
        int clock;
        struct dpll dpll;
};

static const struct dp_link_dpll gen4_dpll[] = {
        { 162000,
                { .p1 = 2, .p2 = 10, .n = 2, .m1 = 23, .m2 = 8 } },
        { 270000,
                { .p1 = 1, .p2 = 10, .n = 1, .m1 = 14, .m2 = 2 } }
};

static const struct dp_link_dpll pch_dpll[] = {
        { 162000,
                { .p1 = 2, .p2 = 10, .n = 1, .m1 = 12, .m2 = 9 } },
        { 270000,
                { .p1 = 1, .p2 = 10, .n = 2, .m1 = 14, .m2 = 8 } }
};

static const struct dp_link_dpll vlv_dpll[] = {
        { 162000,
                { .p1 = 3, .p2 = 2, .n = 5, .m1 = 3, .m2 = 81 } },
        { 270000,
                { .p1 = 2, .p2 = 2, .n = 1, .m1 = 2, .m2 = 27 } }
};

/*
 * CHV supports eDP 1.4 that have  more link rates.
 * Below only provides the fixed rate but exclude variable rate.
 */
static const struct dp_link_dpll chv_dpll[] = {
        /*
         * CHV requires to program fractional division for m2.
         * m2 is stored in fixed point format using formula below
         * (m2_int << 22) | m2_fraction
         */
        { 162000,       /* m2_int = 32, m2_fraction = 1677722 */
                { .p1 = 4, .p2 = 2, .n = 1, .m1 = 2, .m2 = 0x819999a } },
        { 270000,       /* m2_int = 27, m2_fraction = 0 */
                { .p1 = 4, .p2 = 1, .n = 1, .m1 = 2, .m2 = 0x6c00000 } },
        { 540000,       /* m2_int = 27, m2_fraction = 0 */
                { .p1 = 2, .p2 = 1, .n = 1, .m1 = 2, .m2 = 0x6c00000 } }
};

static const int bxt_rates[] = { 162000, 216000, 243000, 270000,
                                  324000, 432000, 540000 };
static const int skl_rates[] = { 162000, 216000, 270000,
                                  324000, 432000, 540000 };
static const int default_rates[] = { 162000, 270000, 540000 };

/**
 * is_edp - is the given port attached to an eDP panel (either CPU or PCH)
 * @intel_dp: DP struct
 *
 * If a CPU or PCH DP output is attached to an eDP panel, this function
 * will return true, and false otherwise.
 */
static bool is_edp(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);

        return intel_dig_port->base.type == INTEL_OUTPUT_EDP;
}

static struct drm_device *intel_dp_to_dev(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);

        return intel_dig_port->base.base.dev;
}

static struct intel_dp *intel_attached_dp(struct drm_connector *connector)
{
        return enc_to_intel_dp(&intel_attached_encoder(connector)->base);
}

static void intel_dp_link_down(struct intel_dp *intel_dp);
static bool edp_panel_vdd_on(struct intel_dp *intel_dp);
static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync);
static void vlv_init_panel_power_sequencer(struct intel_dp *intel_dp);
static void vlv_steal_power_sequencer(struct drm_device *dev,
                                      enum pipe pipe);

static unsigned int intel_dp_unused_lane_mask(int lane_count)
{
        return ~((1 << lane_count) - 1) & 0xf;
}

static int
intel_dp_max_link_bw(struct intel_dp  *intel_dp)
{
        int max_link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE];

        switch (max_link_bw) {
        case DP_LINK_BW_1_62:
        case DP_LINK_BW_2_7:
        case DP_LINK_BW_5_4:
                break;
        default:
                WARN(1, "invalid max DP link bw val %x, using 1.62Gbps\n",
                     max_link_bw);
                max_link_bw = DP_LINK_BW_1_62;
                break;
        }
        return max_link_bw;
}

static u8 intel_dp_max_lane_count(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        u8 source_max, sink_max;

        source_max = 4;
        if (HAS_DDI(dev) && intel_dig_port->port == PORT_A &&
            (intel_dig_port->saved_port_bits & DDI_A_4_LANES) == 0)
                source_max = 2;

        sink_max = drm_dp_max_lane_count(intel_dp->dpcd);

        return min(source_max, sink_max);
}

/*
 * The units on the numbers in the next two are... bizarre.  Examples will
 * make it clearer; this one parallels an example in the eDP spec.
 *
 * intel_dp_max_data_rate for one lane of 2.7GHz evaluates as:
 *
 *     270000 * 1 * 8 / 10 == 216000
 *
 * The actual data capacity of that configuration is 2.16Gbit/s, so the
 * units are decakilobits.  ->clock in a drm_display_mode is in kilohertz -
 * or equivalently, kilopixels per second - so for 1680x1050R it'd be
 * 119000.  At 18bpp that's 2142000 kilobits per second.
 *
 * Thus the strange-looking division by 10 in intel_dp_link_required, to
 * get the result in decakilobits instead of kilobits.
 */

static int
intel_dp_link_required(int pixel_clock, int bpp)
{
        return (pixel_clock * bpp + 9) / 10;
}

static int
intel_dp_max_data_rate(int max_link_clock, int max_lanes)
{
        return (max_link_clock * max_lanes * 8) / 10;
}

static enum drm_mode_status
intel_dp_mode_valid(struct drm_connector *connector,
                    struct drm_display_mode *mode)
{
        struct intel_dp *intel_dp = intel_attached_dp(connector);
        struct intel_connector *intel_connector = to_intel_connector(connector);
        struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
        int target_clock = mode->clock;
        int max_rate, mode_rate, max_lanes, max_link_clock;

        if (is_edp(intel_dp) && fixed_mode) {
                if (mode->hdisplay > fixed_mode->hdisplay)
                        return MODE_PANEL;

                if (mode->vdisplay > fixed_mode->vdisplay)
                        return MODE_PANEL;

                target_clock = fixed_mode->clock;
        }

        max_link_clock = intel_dp_max_link_rate(intel_dp);
        max_lanes = intel_dp_max_lane_count(intel_dp);

        max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
        mode_rate = intel_dp_link_required(target_clock, 18);

        if (mode_rate > max_rate)
                return MODE_CLOCK_HIGH;

        if (mode->clock < 10000)
                return MODE_CLOCK_LOW;

        if (mode->flags & DRM_MODE_FLAG_DBLCLK)
                return MODE_H_ILLEGAL;

        return MODE_OK;
}

uint32_t intel_dp_pack_aux(const uint8_t *src, int src_bytes)
{
        int     i;
        uint32_t v = 0;

        if (src_bytes > 4)
                src_bytes = 4;
        for (i = 0; i < src_bytes; i++)
                v |= ((uint32_t) src[i]) << ((3-i) * 8);
        return v;
}

static void intel_dp_unpack_aux(uint32_t src, uint8_t *dst, int dst_bytes)
{
        int i;
        if (dst_bytes > 4)
                dst_bytes = 4;
        for (i = 0; i < dst_bytes; i++)
                dst[i] = src >> ((3-i) * 8);
}

static void
intel_dp_init_panel_power_sequencer(struct drm_device *dev,
                                    struct intel_dp *intel_dp);
static void
intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
                                              struct intel_dp *intel_dp);

static void pps_lock(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *encoder = &intel_dig_port->base;
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;

        /*
         * See vlv_power_sequencer_reset() why we need
         * a power domain reference here.
         */
        power_domain = intel_display_port_power_domain(encoder);
        intel_display_power_get(dev_priv, power_domain);

        mutex_lock(&dev_priv->pps_mutex);
}

static void pps_unlock(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *encoder = &intel_dig_port->base;
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;

        mutex_unlock(&dev_priv->pps_mutex);

        power_domain = intel_display_port_power_domain(encoder);
        intel_display_power_put(dev_priv, power_domain);
}

static void
vlv_power_sequencer_kick(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum pipe pipe = intel_dp->pps_pipe;
        bool pll_enabled, release_cl_override = false;
        enum dpio_phy phy = DPIO_PHY(pipe);
        enum dpio_channel ch = vlv_pipe_to_channel(pipe);
        uint32_t DP;

        if (WARN(I915_READ(intel_dp->output_reg) & DP_PORT_EN,
                 "skipping pipe %c power seqeuncer kick due to port %c being active\n",
                 pipe_name(pipe), port_name(intel_dig_port->port)))
                return;

        DRM_DEBUG_KMS("kicking pipe %c power sequencer for port %c\n",
                      pipe_name(pipe), port_name(intel_dig_port->port));

        /* Preserve the BIOS-computed detected bit. This is
         * supposed to be read-only.
         */
        DP = I915_READ(intel_dp->output_reg) & DP_DETECTED;
        DP |= DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
        DP |= DP_PORT_WIDTH(1);
        DP |= DP_LINK_TRAIN_PAT_1;

        if (IS_CHERRYVIEW(dev))
                DP |= DP_PIPE_SELECT_CHV(pipe);
        else if (pipe == PIPE_B)
                DP |= DP_PIPEB_SELECT;

        pll_enabled = I915_READ(DPLL(pipe)) & DPLL_VCO_ENABLE;

        /*
         * The DPLL for the pipe must be enabled for this to work.
         * So enable temporarily it if it's not already enabled.
         */
        if (!pll_enabled) {
                release_cl_override = IS_CHERRYVIEW(dev) &&
                        !chv_phy_powergate_ch(dev_priv, phy, ch, true);

                vlv_force_pll_on(dev, pipe, IS_CHERRYVIEW(dev) ?
                                 &chv_dpll[0].dpll : &vlv_dpll[0].dpll);
        }

        /*
         * Similar magic as in intel_dp_enable_port().
         * We _must_ do this port enable + disable trick
         * to make this power seqeuencer lock onto the port.
         * Otherwise even VDD force bit won't work.
         */
        I915_WRITE(intel_dp->output_reg, DP);
        POSTING_READ(intel_dp->output_reg);

        I915_WRITE(intel_dp->output_reg, DP | DP_PORT_EN);
        POSTING_READ(intel_dp->output_reg);

        I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
        POSTING_READ(intel_dp->output_reg);

        if (!pll_enabled) {
                vlv_force_pll_off(dev, pipe);

                if (release_cl_override)
                        chv_phy_powergate_ch(dev_priv, phy, ch, false);
        }
}

static enum pipe
vlv_power_sequencer_pipe(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_encoder *encoder;
        unsigned int pipes = (1 << PIPE_A) | (1 << PIPE_B);
        enum pipe pipe;

        lockdep_assert_held(&dev_priv->pps_mutex);

        /* We should never land here with regular DP ports */
        WARN_ON(!is_edp(intel_dp));

        if (intel_dp->pps_pipe != INVALID_PIPE)
                return intel_dp->pps_pipe;

        /*
         * We don't have power sequencer currently.
         * Pick one that's not used by other ports.
         */
        list_for_each_entry(encoder, &dev->mode_config.encoder_list,
                            base.head) {
                struct intel_dp *tmp;

                if (encoder->type != INTEL_OUTPUT_EDP)
                        continue;

                tmp = enc_to_intel_dp(&encoder->base);

                if (tmp->pps_pipe != INVALID_PIPE)
                        pipes &= ~(1 << tmp->pps_pipe);
        }

        /*
         * Didn't find one. This should not happen since there
         * are two power sequencers and up to two eDP ports.
         */
        if (WARN_ON(pipes == 0))
                pipe = PIPE_A;
        else
                pipe = ffs(pipes) - 1;

        vlv_steal_power_sequencer(dev, pipe);
        intel_dp->pps_pipe = pipe;

        DRM_DEBUG_KMS("picked pipe %c power sequencer for port %c\n",
                      pipe_name(intel_dp->pps_pipe),
                      port_name(intel_dig_port->port));

        /* init power sequencer on this pipe and port */
        intel_dp_init_panel_power_sequencer(dev, intel_dp);
        intel_dp_init_panel_power_sequencer_registers(dev, intel_dp);

        /*
         * Even vdd force doesn't work until we've made
         * the power sequencer lock in on the port.
         */
        vlv_power_sequencer_kick(intel_dp);

        return intel_dp->pps_pipe;
}

typedef bool (*vlv_pipe_check)(struct drm_i915_private *dev_priv,
                               enum pipe pipe);

static bool vlv_pipe_has_pp_on(struct drm_i915_private *dev_priv,
                               enum pipe pipe)
{
        return I915_READ(VLV_PIPE_PP_STATUS(pipe)) & PP_ON;
}

static bool vlv_pipe_has_vdd_on(struct drm_i915_private *dev_priv,
                                enum pipe pipe)
{
        return I915_READ(VLV_PIPE_PP_CONTROL(pipe)) & EDP_FORCE_VDD;
}

static bool vlv_pipe_any(struct drm_i915_private *dev_priv,
                         enum pipe pipe)
{
        return true;
}

static enum pipe
vlv_initial_pps_pipe(struct drm_i915_private *dev_priv,
                     enum port port,
                     vlv_pipe_check pipe_check)
{
        enum pipe pipe;

        for (pipe = PIPE_A; pipe <= PIPE_B; pipe++) {
                u32 port_sel = I915_READ(VLV_PIPE_PP_ON_DELAYS(pipe)) &
                        PANEL_PORT_SELECT_MASK;

                if (port_sel != PANEL_PORT_SELECT_VLV(port))
                        continue;

                if (!pipe_check(dev_priv, pipe))
                        continue;

                return pipe;
        }

        return INVALID_PIPE;
}

static void
vlv_initial_power_sequencer_setup(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = intel_dig_port->port;

        lockdep_assert_held(&dev_priv->pps_mutex);

        /* try to find a pipe with this port selected */
        /* first pick one where the panel is on */
        intel_dp->pps_pipe = vlv_initial_pps_pipe(dev_priv, port,
                                                  vlv_pipe_has_pp_on);
        /* didn't find one? pick one where vdd is on */
        if (intel_dp->pps_pipe == INVALID_PIPE)
                intel_dp->pps_pipe = vlv_initial_pps_pipe(dev_priv, port,
                                                          vlv_pipe_has_vdd_on);
        /* didn't find one? pick one with just the correct port */
        if (intel_dp->pps_pipe == INVALID_PIPE)
                intel_dp->pps_pipe = vlv_initial_pps_pipe(dev_priv, port,
                                                          vlv_pipe_any);

        /* didn't find one? just let vlv_power_sequencer_pipe() pick one when needed */
        if (intel_dp->pps_pipe == INVALID_PIPE) {
                DRM_DEBUG_KMS("no initial power sequencer for port %c\n",
                              port_name(port));
                return;
        }

        DRM_DEBUG_KMS("initial power sequencer for port %c: pipe %c\n",
                      port_name(port), pipe_name(intel_dp->pps_pipe));

        intel_dp_init_panel_power_sequencer(dev, intel_dp);
        intel_dp_init_panel_power_sequencer_registers(dev, intel_dp);
}

void vlv_power_sequencer_reset(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct intel_encoder *encoder;

        if (WARN_ON(!IS_VALLEYVIEW(dev)))
                return;

        /*
         * We can't grab pps_mutex here due to deadlock with power_domain
         * mutex when power_domain functions are called while holding pps_mutex.
         * That also means that in order to use pps_pipe the code needs to
         * hold both a power domain reference and pps_mutex, and the power domain
         * reference get/put must be done while _not_ holding pps_mutex.
         * pps_{lock,unlock}() do these steps in the correct order, so one
         * should use them always.
         */

        list_for_each_entry(encoder, &dev->mode_config.encoder_list, base.head) {
                struct intel_dp *intel_dp;

                if (encoder->type != INTEL_OUTPUT_EDP)
                        continue;

                intel_dp = enc_to_intel_dp(&encoder->base);
                intel_dp->pps_pipe = INVALID_PIPE;
        }
}

static u32 _pp_ctrl_reg(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);

        if (IS_BROXTON(dev))
                return BXT_PP_CONTROL(0);
        else if (HAS_PCH_SPLIT(dev))
                return PCH_PP_CONTROL;
        else
                return VLV_PIPE_PP_CONTROL(vlv_power_sequencer_pipe(intel_dp));
}

static u32 _pp_stat_reg(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);

        if (IS_BROXTON(dev))
                return BXT_PP_STATUS(0);
        else if (HAS_PCH_SPLIT(dev))
                return PCH_PP_STATUS;
        else
                return VLV_PIPE_PP_STATUS(vlv_power_sequencer_pipe(intel_dp));
}

/* Reboot notifier handler to shutdown panel power to guarantee T12 timing
   This function only applicable when panel PM state is not to be tracked */
static int edp_notify_handler(struct notifier_block *this, unsigned long code,
                              void *unused)
{
        struct intel_dp *intel_dp = container_of(this, typeof(* intel_dp),
                                                 edp_notifier);
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!is_edp(intel_dp) || code != SYS_RESTART)
                return 0;

        pps_lock(intel_dp);

        if (IS_VALLEYVIEW(dev)) {
                enum pipe pipe = vlv_power_sequencer_pipe(intel_dp);
                u32 pp_ctrl_reg, pp_div_reg;
                u32 pp_div;

                pp_ctrl_reg = VLV_PIPE_PP_CONTROL(pipe);
                pp_div_reg  = VLV_PIPE_PP_DIVISOR(pipe);
                pp_div = I915_READ(pp_div_reg);
                pp_div &= PP_REFERENCE_DIVIDER_MASK;

                /* 0x1F write to PP_DIV_REG sets max cycle delay */
                I915_WRITE(pp_div_reg, pp_div | 0x1F);
                I915_WRITE(pp_ctrl_reg, PANEL_UNLOCK_REGS | PANEL_POWER_OFF);
                msleep(intel_dp->panel_power_cycle_delay);
        }

        pps_unlock(intel_dp);

        return 0;
}

static bool edp_have_panel_power(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (IS_VALLEYVIEW(dev) &&
            intel_dp->pps_pipe == INVALID_PIPE)
                return false;

        return (I915_READ(_pp_stat_reg(intel_dp)) & PP_ON) != 0;
}

static bool edp_have_panel_vdd(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (IS_VALLEYVIEW(dev) &&
            intel_dp->pps_pipe == INVALID_PIPE)
                return false;

        return I915_READ(_pp_ctrl_reg(intel_dp)) & EDP_FORCE_VDD;
}

static void
intel_dp_check_edp(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!is_edp(intel_dp))
                return;

        if (!edp_have_panel_power(intel_dp) && !edp_have_panel_vdd(intel_dp)) {
                WARN(1, "eDP powered off while attempting aux channel communication.\n");
                DRM_DEBUG_KMS("Status 0x%08x Control 0x%08x\n",
                              I915_READ(_pp_stat_reg(intel_dp)),
                              I915_READ(_pp_ctrl_reg(intel_dp)));
        }
}

static uint32_t
intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t ch_ctl = intel_dp->aux_ch_ctl_reg;
        uint32_t status;
        bool done;

#define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
        if (has_aux_irq)
                done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
                                          msecs_to_jiffies_timeout(10));
        else
                done = wait_for_atomic(C, 10) == 0;
        if (!done)
                DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
                          has_aux_irq);
#undef C

        return status;
}

static uint32_t i9xx_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;

        /*
         * The clock divider is based off the hrawclk, and would like to run at
         * 2MHz.  So, take the hrawclk value and divide by 2 and use that
         */
        return index ? 0 : intel_hrawclk(dev) / 2;
}

static uint32_t ilk_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (index)
                return 0;

        if (intel_dig_port->port == PORT_A) {
                return DIV_ROUND_UP(dev_priv->cdclk_freq, 2000);

        } else {
                return DIV_ROUND_UP(intel_pch_rawclk(dev), 2);
        }
}

static uint32_t hsw_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (intel_dig_port->port == PORT_A) {
                if (index)
                        return 0;
                return DIV_ROUND_CLOSEST(dev_priv->cdclk_freq, 2000);
        } else if (dev_priv->pch_id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
                /* Workaround for non-ULT HSW */
                switch (index) {
                case 0: return 63;
                case 1: return 72;
                default: return 0;
                }
        } else  {
                return index ? 0 : DIV_ROUND_UP(intel_pch_rawclk(dev), 2);
        }
}

static uint32_t vlv_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        return index ? 0 : 100;
}

static uint32_t skl_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
{
        /*
         * SKL doesn't need us to program the AUX clock divider (Hardware will
         * derive the clock from CDCLK automatically). We still implement the
         * get_aux_clock_divider vfunc to plug-in into the existing code.
         */
        return index ? 0 : 1;
}

static uint32_t i9xx_get_aux_send_ctl(struct intel_dp *intel_dp,
                                      bool has_aux_irq,
                                      int send_bytes,
                                      uint32_t aux_clock_divider)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        uint32_t precharge, timeout;

        if (IS_GEN6(dev))
                precharge = 3;
        else
                precharge = 5;

        if (IS_BROADWELL(dev) && intel_dp->aux_ch_ctl_reg == DPA_AUX_CH_CTL)
                timeout = DP_AUX_CH_CTL_TIME_OUT_600us;
        else
                timeout = DP_AUX_CH_CTL_TIME_OUT_400us;

        return DP_AUX_CH_CTL_SEND_BUSY |
               DP_AUX_CH_CTL_DONE |
               (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) |
               DP_AUX_CH_CTL_TIME_OUT_ERROR |
               timeout |
               DP_AUX_CH_CTL_RECEIVE_ERROR |
               (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
               (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
               (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT);
}

static uint32_t skl_get_aux_send_ctl(struct intel_dp *intel_dp,
                                      bool has_aux_irq,
                                      int send_bytes,
                                      uint32_t unused)
{
        return DP_AUX_CH_CTL_SEND_BUSY |
               DP_AUX_CH_CTL_DONE |
               (has_aux_irq ? DP_AUX_CH_CTL_INTERRUPT : 0) |
               DP_AUX_CH_CTL_TIME_OUT_ERROR |
               DP_AUX_CH_CTL_TIME_OUT_1600us |
               DP_AUX_CH_CTL_RECEIVE_ERROR |
               (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
               DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
}

static int
intel_dp_aux_ch(struct intel_dp *intel_dp,
                const uint8_t *send, int send_bytes,
                uint8_t *recv, int recv_size)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t ch_ctl = intel_dp->aux_ch_ctl_reg;
        uint32_t ch_data = ch_ctl + 4;
        uint32_t aux_clock_divider;
        int i, ret, recv_bytes;
        uint32_t status;
        int try, clock = 0;
        bool has_aux_irq = HAS_AUX_IRQ(dev);
        bool vdd;

        pps_lock(intel_dp);

        /*
         * We will be called with VDD already enabled for dpcd/edid/oui reads.
         * In such cases we want to leave VDD enabled and it's up to upper layers
         * to turn it off. But for eg. i2c-dev access we need to turn it on/off
         * ourselves.
         */
        vdd = edp_panel_vdd_on(intel_dp);

        /* dp aux is extremely sensitive to irq latency, hence request the
         * lowest possible wakeup latency and so prevent the cpu from going into
         * deep sleep states.
         */
        pm_qos_update_request(&dev_priv->pm_qos, 0);

        intel_dp_check_edp(intel_dp);

        intel_aux_display_runtime_get(dev_priv);

        /* Try to wait for any previous AUX channel activity */
        for (try = 0; try < 3; try++) {
                status = I915_READ_NOTRACE(ch_ctl);
                if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
                        break;
                msleep(1);
        }

        if (try == 3) {
                static u32 last_status = -1;
                const u32 status = I915_READ(ch_ctl);

                if (status != last_status) {
                        WARN(1, "dp_aux_ch not started status 0x%08x\n",
                             status);
                        last_status = status;
                }

                ret = -EBUSY;
                goto out;
        }

        /* Only 5 data registers! */
        if (WARN_ON(send_bytes > 20 || recv_size > 20)) {
                ret = -E2BIG;
                goto out;
        }

        while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
                u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
                                                          has_aux_irq,
                                                          send_bytes,
                                                          aux_clock_divider);

                /* Must try at least 3 times according to DP spec */
                for (try = 0; try < 5; try++) {
                        /* Load the send data into the aux channel data registers */
                        for (i = 0; i < send_bytes; i += 4)
                                I915_WRITE(ch_data + i,
                                           intel_dp_pack_aux(send + i,
                                                             send_bytes - i));

                        /* Send the command and wait for it to complete */
                        I915_WRITE(ch_ctl, send_ctl);

                        status = intel_dp_aux_wait_done(intel_dp, has_aux_irq);

                        /* Clear done status and any errors */
                        I915_WRITE(ch_ctl,
                                   status |
                                   DP_AUX_CH_CTL_DONE |
                                   DP_AUX_CH_CTL_TIME_OUT_ERROR |
                                   DP_AUX_CH_CTL_RECEIVE_ERROR);

                        if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR)
                                continue;

                        /* DP CTS 1.2 Core Rev 1.1, 4.2.1.1 & 4.2.1.2
                         *   400us delay required for errors and timeouts
                         *   Timeout errors from the HW already meet this
                         *   requirement so skip to next iteration
                         */
                        if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
                                usleep_range(400, 500);
                                continue;
                        }
                        if (status & DP_AUX_CH_CTL_DONE)
                                goto done;
                }
        }

        if ((status & DP_AUX_CH_CTL_DONE) == 0) {
                DRM_ERROR("dp_aux_ch not done status 0x%08x\n", status);
                ret = -EBUSY;
                goto out;
        }

done:
        /* Check for timeout or receive error.
         * Timeouts occur when the sink is not connected
         */
        if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
                DRM_ERROR("dp_aux_ch receive error status 0x%08x\n", status);
                ret = -EIO;
                goto out;
        }

        /* Timeouts occur when the device isn't connected, so they're
         * "normal" -- don't fill the kernel log with these */
        if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
                DRM_DEBUG_KMS("dp_aux_ch timeout status 0x%08x\n", status);
                ret = -ETIMEDOUT;
                goto out;
        }

        /* Unload any bytes sent back from the other side */
        recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
                      DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
        if (recv_bytes > recv_size)
                recv_bytes = recv_size;

        for (i = 0; i < recv_bytes; i += 4)
                intel_dp_unpack_aux(I915_READ(ch_data + i),
                                    recv + i, recv_bytes - i);

        ret = recv_bytes;
out:
        pm_qos_update_request(&dev_priv->pm_qos, PM_QOS_DEFAULT_VALUE);
        intel_aux_display_runtime_put(dev_priv);

        if (vdd)
                edp_panel_vdd_off(intel_dp, false);

        pps_unlock(intel_dp);

        return ret;
}

#define BARE_ADDRESS_SIZE       3
#define HEADER_SIZE             (BARE_ADDRESS_SIZE + 1)
static ssize_t
intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
{
        struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux);
        uint8_t txbuf[20], rxbuf[20];
        size_t txsize, rxsize;
        int ret;

        txbuf[0] = (msg->request << 4) |
                ((msg->address >> 16) & 0xf);
        txbuf[1] = (msg->address >> 8) & 0xff;
        txbuf[2] = msg->address & 0xff;
        txbuf[3] = msg->size - 1;

        switch (msg->request & ~DP_AUX_I2C_MOT) {
        case DP_AUX_NATIVE_WRITE:
        case DP_AUX_I2C_WRITE:
        case DP_AUX_I2C_WRITE_STATUS_UPDATE:
                txsize = msg->size ? HEADER_SIZE + msg->size : BARE_ADDRESS_SIZE;
                rxsize = 2; /* 0 or 1 data bytes */

                if (WARN_ON(txsize > 20))
                        return -E2BIG;

                memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);

                ret = intel_dp_aux_ch(intel_dp, txbuf, txsize, rxbuf, rxsize);
                if (ret > 0) {
                        msg->reply = rxbuf[0] >> 4;

                        if (ret > 1) {
                                /* Number of bytes written in a short write. */
                                ret = clamp_t(int, rxbuf[1], 0, msg->size);
                        } else {
                                /* Return payload size. */
                                ret = msg->size;
                        }
                }
                break;

        case DP_AUX_NATIVE_READ:
        case DP_AUX_I2C_READ:
                txsize = msg->size ? HEADER_SIZE : BARE_ADDRESS_SIZE;
                rxsize = msg->size + 1;

                if (WARN_ON(rxsize > 20))
                        return -E2BIG;

                ret = intel_dp_aux_ch(intel_dp, txbuf, txsize, rxbuf, rxsize);
                if (ret > 0) {
                        msg->reply = rxbuf[0] >> 4;
                        /*
                         * Assume happy day, and copy the data. The caller is
                         * expected to check msg->reply before touching it.
                         *
                         * Return payload size.
                         */
                        ret--;
                        memcpy(msg->buffer, rxbuf + 1, ret);
                }
                break;

        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

static void
intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        enum port port = intel_dig_port->port;
        struct ddi_vbt_port_info *info = &dev_priv->vbt.ddi_port_info[port];
        const char *name = NULL;
        uint32_t porte_aux_ctl_reg = DPA_AUX_CH_CTL;
        int ret;

        /* On SKL we don't have Aux for port E so we rely on VBT to set
         * a proper alternate aux channel.
         */
        if (IS_SKYLAKE(dev) && port == PORT_E) {
                switch (info->alternate_aux_channel) {
                case DP_AUX_B:
                        porte_aux_ctl_reg = DPB_AUX_CH_CTL;
                        break;
                case DP_AUX_C:
                        porte_aux_ctl_reg = DPC_AUX_CH_CTL;
                        break;
                case DP_AUX_D:
                        porte_aux_ctl_reg = DPD_AUX_CH_CTL;
                        break;
                case DP_AUX_A:
                default:
                        porte_aux_ctl_reg = DPA_AUX_CH_CTL;
                }
        }

        switch (port) {
        case PORT_A:
                intel_dp->aux_ch_ctl_reg = DPA_AUX_CH_CTL;
                name = "DPDDC-A";
                break;
        case PORT_B:
                intel_dp->aux_ch_ctl_reg = PCH_DPB_AUX_CH_CTL;
                name = "DPDDC-B";
                break;
        case PORT_C:
                intel_dp->aux_ch_ctl_reg = PCH_DPC_AUX_CH_CTL;
                name = "DPDDC-C";
                break;
        case PORT_D:
                intel_dp->aux_ch_ctl_reg = PCH_DPD_AUX_CH_CTL;
                name = "DPDDC-D";
                break;
        case PORT_E:
                intel_dp->aux_ch_ctl_reg = porte_aux_ctl_reg;
                name = "DPDDC-E";
                break;
        default:
                BUG();
        }

        /*
         * The AUX_CTL register is usually DP_CTL + 0x10.
         *
         * On Haswell and Broadwell though:
         *   - Both port A DDI_BUF_CTL and DDI_AUX_CTL are on the CPU
         *   - Port B/C/D AUX channels are on the PCH, DDI_BUF_CTL on the CPU
         *
         * Skylake moves AUX_CTL back next to DDI_BUF_CTL, on the CPU.
         */
        if (!IS_HASWELL(dev) && !IS_BROADWELL(dev) && port != PORT_E)
                intel_dp->aux_ch_ctl_reg = intel_dp->output_reg + 0x10;

        intel_dp->aux.name = name;
        intel_dp->aux.dev = dev->dev;
        intel_dp->aux.transfer = intel_dp_aux_transfer;

        DRM_DEBUG_KMS("registering %s bus for %s\n", name,
                      connector->base.kdev->kobj.name);

        ret = drm_dp_aux_register(&intel_dp->aux);
        if (ret < 0) {
                DRM_ERROR("drm_dp_aux_register() for %s failed (%d)\n",
                          name, ret);
                return;
        }

        ret = sysfs_create_link(&connector->base.kdev->kobj,
                                &intel_dp->aux.ddc.dev.kobj,
                                intel_dp->aux.ddc.dev.kobj.name);
        if (ret < 0) {
                DRM_ERROR("sysfs_create_link() for %s failed (%d)\n", name, ret);
                drm_dp_aux_unregister(&intel_dp->aux);
        }
}

static void
intel_dp_connector_unregister(struct intel_connector *intel_connector)
{
        struct intel_dp *intel_dp = intel_attached_dp(&intel_connector->base);

        if (!intel_connector->mst_port)
                sysfs_remove_link(&intel_connector->base.kdev->kobj,
                                  intel_dp->aux.ddc.dev.kobj.name);
        intel_connector_unregister(intel_connector);
}

static void
skl_edp_set_pll_config(struct intel_crtc_state *pipe_config)
{
        u32 ctrl1;

        memset(&pipe_config->dpll_hw_state, 0,
               sizeof(pipe_config->dpll_hw_state));

        pipe_config->ddi_pll_sel = SKL_DPLL0;
        pipe_config->dpll_hw_state.cfgcr1 = 0;
        pipe_config->dpll_hw_state.cfgcr2 = 0;

        ctrl1 = DPLL_CTRL1_OVERRIDE(SKL_DPLL0);
        switch (pipe_config->port_clock / 2) {
        case 81000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810,
                                              SKL_DPLL0);
                break;
        case 135000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1350,
                                              SKL_DPLL0);
                break;
        case 270000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2700,
                                              SKL_DPLL0);
                break;
        case 162000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1620,
                                              SKL_DPLL0);
                break;
        /* TBD: For DP link rates 2.16 GHz and 4.32 GHz, VCO is 8640 which
        results in CDCLK change. Need to handle the change of CDCLK by
        disabling pipes and re-enabling them */
        case 108000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080,
                                              SKL_DPLL0);
                break;
        case 216000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2160,
                                              SKL_DPLL0);
                break;

        }
        pipe_config->dpll_hw_state.ctrl1 = ctrl1;
}

void
hsw_dp_set_ddi_pll_sel(struct intel_crtc_state *pipe_config)
{
        memset(&pipe_config->dpll_hw_state, 0,
               sizeof(pipe_config->dpll_hw_state));

        switch (pipe_config->port_clock / 2) {
        case 81000:
                pipe_config->ddi_pll_sel = PORT_CLK_SEL_LCPLL_810;
                break;
        case 135000:
                pipe_config->ddi_pll_sel = PORT_CLK_SEL_LCPLL_1350;
                break;
        case 270000:
                pipe_config->ddi_pll_sel = PORT_CLK_SEL_LCPLL_2700;
                break;
        }
}

static int
intel_dp_sink_rates(struct intel_dp *intel_dp, const int **sink_rates)
{
        if (intel_dp->num_sink_rates) {
                *sink_rates = intel_dp->sink_rates;
                return intel_dp->num_sink_rates;
        }

        *sink_rates = default_rates;

        return (intel_dp_max_link_bw(intel_dp) >> 3) + 1;
}

static bool intel_dp_source_supports_hbr2(struct drm_device *dev)
{
        /* WaDisableHBR2:skl */
        if (IS_SKYLAKE(dev) && INTEL_REVID(dev) <= SKL_REVID_B0)
                return false;

        if ((IS_HASWELL(dev) && !IS_HSW_ULX(dev)) || IS_BROADWELL(dev) ||
            (INTEL_INFO(dev)->gen >= 9))
                return true;
        else
                return false;
}

static int
intel_dp_source_rates(struct drm_device *dev, const int **source_rates)
{
        int size;

        if (IS_BROXTON(dev)) {
                *source_rates = bxt_rates;
                size = ARRAY_SIZE(bxt_rates);
        } else if (IS_SKYLAKE(dev)) {
                *source_rates = skl_rates;
                size = ARRAY_SIZE(skl_rates);
        } else {
                *source_rates = default_rates;
                size = ARRAY_SIZE(default_rates);
        }

        /* This depends on the fact that 5.4 is last value in the array */
        if (!intel_dp_source_supports_hbr2(dev))
                size--;

        return size;
}

static void
intel_dp_set_clock(struct intel_encoder *encoder,
                   struct intel_crtc_state *pipe_config)
{
        struct drm_device *dev = encoder->base.dev;
        const struct dp_link_dpll *divisor = NULL;
        int i, count = 0;

        if (IS_G4X(dev)) {
                divisor = gen4_dpll;
                count = ARRAY_SIZE(gen4_dpll);
        } else if (HAS_PCH_SPLIT(dev)) {
                divisor = pch_dpll;
                count = ARRAY_SIZE(pch_dpll);
        } else if (IS_CHERRYVIEW(dev)) {
                divisor = chv_dpll;
                count = ARRAY_SIZE(chv_dpll);
        } else if (IS_VALLEYVIEW(dev)) {
                divisor = vlv_dpll;
                count = ARRAY_SIZE(vlv_dpll);
        }

        if (divisor && count) {
                for (i = 0; i < count; i++) {
                        if (pipe_config->port_clock == divisor[i].clock) {
                                pipe_config->dpll = divisor[i].dpll;
                                pipe_config->clock_set = true;
                                break;
                        }
                }
        }
}

static int intersect_rates(const int *source_rates, int source_len,
                           const int *sink_rates, int sink_len,
                           int *common_rates)
{
        int i = 0, j = 0, k = 0;

        while (i < source_len && j < sink_len) {
                if (source_rates[i] == sink_rates[j]) {
                        if (WARN_ON(k >= DP_MAX_SUPPORTED_RATES))
                                return k;
                        common_rates[k] = source_rates[i];
                        ++k;
                        ++i;
                        ++j;
                } else if (source_rates[i] < sink_rates[j]) {
                        ++i;
                } else {
                        ++j;
                }
        }
        return k;
}

static int intel_dp_common_rates(struct intel_dp *intel_dp,
                                 int *common_rates)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        const int *source_rates, *sink_rates;
        int source_len, sink_len;

        sink_len = intel_dp_sink_rates(intel_dp, &sink_rates);
        source_len = intel_dp_source_rates(dev, &source_rates);

        return intersect_rates(source_rates, source_len,
                               sink_rates, sink_len,
                               common_rates);
}

static void snprintf_int_array(char *str, size_t len,
                               const int *array, int nelem)
{
        int i;

        str[0] = '\0';

        for (i = 0; i < nelem; i++) {
                int r = snprintf(str, len, "%s%d", i ? ", " : "", array[i]);
                if (r >= len)
                        return;
                str += r;
                len -= r;
        }
}

static void intel_dp_print_rates(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        const int *source_rates, *sink_rates;
        int source_len, sink_len, common_len;
        int common_rates[DP_MAX_SUPPORTED_RATES];
        char str[128]; /* FIXME: too big for stack? */

        if ((drm_debug & DRM_UT_KMS) == 0)
                return;

        source_len = intel_dp_source_rates(dev, &source_rates);
        snprintf_int_array(str, sizeof(str), source_rates, source_len);
        DRM_DEBUG_KMS("source rates: %s\n", str);

        sink_len = intel_dp_sink_rates(intel_dp, &sink_rates);
        snprintf_int_array(str, sizeof(str), sink_rates, sink_len);
        DRM_DEBUG_KMS("sink rates: %s\n", str);

        common_len = intel_dp_common_rates(intel_dp, common_rates);
        snprintf_int_array(str, sizeof(str), common_rates, common_len);
        DRM_DEBUG_KMS("common rates: %s\n", str);
}

static int rate_to_index(int find, const int *rates)
{
        int i = 0;

        for (i = 0; i < DP_MAX_SUPPORTED_RATES; ++i)
                if (find == rates[i])
                        break;

        return i;
}

int
intel_dp_max_link_rate(struct intel_dp *intel_dp)
{
        int rates[DP_MAX_SUPPORTED_RATES] = {};
        int len;

        len = intel_dp_common_rates(intel_dp, rates);
        if (WARN_ON(len <= 0))
                return 162000;

        return rates[rate_to_index(0, rates) - 1];
}

int intel_dp_rate_select(struct intel_dp *intel_dp, int rate)
{
        return rate_to_index(rate, intel_dp->sink_rates);
}

static void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
                                  uint8_t *link_bw, uint8_t *rate_select)
{
        if (intel_dp->num_sink_rates) {
                *link_bw = 0;
                *rate_select =
                        intel_dp_rate_select(intel_dp, port_clock);
        } else {
                *link_bw = drm_dp_link_rate_to_bw_code(port_clock);
                *rate_select = 0;
        }
}

bool
intel_dp_compute_config(struct intel_encoder *encoder,
                        struct intel_crtc_state *pipe_config)
{
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        enum port port = dp_to_dig_port(intel_dp)->port;
        struct intel_crtc *intel_crtc = to_intel_crtc(pipe_config->base.crtc);
        struct intel_connector *intel_connector = intel_dp->attached_connector;
        int lane_count, clock;
        int min_lane_count = 1;
        int max_lane_count = intel_dp_max_lane_count(intel_dp);
        /* Conveniently, the link BW constants become indices with a shift...*/
        int min_clock = 0;
        int max_clock;
        int bpp, mode_rate;
        int link_avail, link_clock;
        int common_rates[DP_MAX_SUPPORTED_RATES] = {};
        int common_len;
        uint8_t link_bw, rate_select;

        common_len = intel_dp_common_rates(intel_dp, common_rates);

        /* No common link rates between source and sink */
        WARN_ON(common_len <= 0);

        max_clock = common_len - 1;

        if (HAS_PCH_SPLIT(dev) && !HAS_DDI(dev) && port != PORT_A)
                pipe_config->has_pch_encoder = true;

        pipe_config->has_dp_encoder = true;
        pipe_config->has_drrs = false;
        pipe_config->has_audio = intel_dp->has_audio && port != PORT_A;

        if (is_edp(intel_dp) && intel_connector->panel.fixed_mode) {
                intel_fixed_panel_mode(intel_connector->panel.fixed_mode,
                                       adjusted_mode);

                if (INTEL_INFO(dev)->gen >= 9) {
                        int ret;
                        ret = skl_update_scaler_crtc(pipe_config);
                        if (ret)
                                return ret;
                }

                if (!HAS_PCH_SPLIT(dev))
                        intel_gmch_panel_fitting(intel_crtc, pipe_config,
                                                 intel_connector->panel.fitting_mode);
                else
                        intel_pch_panel_fitting(intel_crtc, pipe_config,
                                                intel_connector->panel.fitting_mode);
        }

        if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)
                return false;

        DRM_DEBUG_KMS("DP link computation with max lane count %i "
                      "max bw %d pixel clock %iKHz\n",
                      max_lane_count, common_rates[max_clock],
                      adjusted_mode->crtc_clock);

        /* Walk through all bpp values. Luckily they're all nicely spaced with 2
         * bpc in between. */
        bpp = pipe_config->pipe_bpp;
        if (is_edp(intel_dp)) {

                /* Get bpp from vbt only for panels that dont have bpp in edid */
                if (intel_connector->base.display_info.bpc == 0 &&
                        (dev_priv->vbt.edp_bpp && dev_priv->vbt.edp_bpp < bpp)) {
                        DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided %i\n",
                                      dev_priv->vbt.edp_bpp);
                        bpp = dev_priv->vbt.edp_bpp;
                }

                /*
                 * Use the maximum clock and number of lanes the eDP panel
                 * advertizes being capable of. The panels are generally
                 * designed to support only a single clock and lane
                 * configuration, and typically these values correspond to the
                 * native resolution of the panel.
                 */
                min_lane_count = max_lane_count;
                min_clock = max_clock;
        }

        for (; bpp >= 6*3; bpp -= 2*3) {
                mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
                                                   bpp);

                for (clock = min_clock; clock <= max_clock; clock++) {
                        for (lane_count = min_lane_count;
                                lane_count <= max_lane_count;
                                lane_count <<= 1) {

                                link_clock = common_rates[clock];
                                link_avail = intel_dp_max_data_rate(link_clock,
                                                                    lane_count);

                                if (mode_rate <= link_avail) {
                                        goto found;
                                }
                        }
                }
        }

        return false;

found:
        if (intel_dp->color_range_auto) {
                /*
                 * See:
                 * CEA-861-E - 5.1 Default Encoding Parameters
                 * VESA DisplayPort Ver.1.2a - 5.1.1.1 Video Colorimetry
                 */
                pipe_config->limited_color_range =
                        bpp != 18 && drm_match_cea_mode(adjusted_mode) > 1;
        } else {
                pipe_config->limited_color_range =
                        intel_dp->limited_color_range;
        }

        pipe_config->lane_count = lane_count;

        pipe_config->pipe_bpp = bpp;
        pipe_config->port_clock = common_rates[clock];

        intel_dp_compute_rate(intel_dp, pipe_config->port_clock,
                              &link_bw, &rate_select);

        DRM_DEBUG_KMS("DP link bw %02x rate select %02x lane count %d clock %d bpp %d\n",
                      link_bw, rate_select, pipe_config->lane_count,
                      pipe_config->port_clock, bpp);
        DRM_DEBUG_KMS("DP link bw required %i available %i\n",
                      mode_rate, link_avail);

        intel_link_compute_m_n(bpp, lane_count,
                               adjusted_mode->crtc_clock,
                               pipe_config->port_clock,
                               &pipe_config->dp_m_n);

        if (intel_connector->panel.downclock_mode != NULL &&
                dev_priv->drrs.type == SEAMLESS_DRRS_SUPPORT) {
                        pipe_config->has_drrs = true;
                        intel_link_compute_m_n(bpp, lane_count,
                                intel_connector->panel.downclock_mode->clock,
                                pipe_config->port_clock,
                                &pipe_config->dp_m2_n2);
        }

        if (IS_SKYLAKE(dev) && is_edp(intel_dp))
                skl_edp_set_pll_config(pipe_config);
        else if (IS_BROXTON(dev))
                /* handled in ddi */;
        else if (IS_HASWELL(dev) || IS_BROADWELL(dev))
                hsw_dp_set_ddi_pll_sel(pipe_config);
        else
                intel_dp_set_clock(encoder, pipe_config);

        return true;
}

static void ironlake_set_pll_cpu_edp(struct intel_dp *intel_dp)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct intel_crtc *crtc = to_intel_crtc(dig_port->base.base.crtc);
        struct drm_device *dev = crtc->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dpa_ctl;

        DRM_DEBUG_KMS("eDP PLL enable for clock %d\n",
                      crtc->config->port_clock);
        dpa_ctl = I915_READ(DP_A);
        dpa_ctl &= ~DP_PLL_FREQ_MASK;

        if (crtc->config->port_clock == 162000) {
                /* For a long time we've carried around a ILK-DevA w/a for the
                 * 160MHz clock. If we're really unlucky, it's still required.
                 */
                DRM_DEBUG_KMS("160MHz cpu eDP clock, might need ilk devA w/a\n");
                dpa_ctl |= DP_PLL_FREQ_160MHZ;
                intel_dp->DP |= DP_PLL_FREQ_160MHZ;
        } else {
                dpa_ctl |= DP_PLL_FREQ_270MHZ;
                intel_dp->DP |= DP_PLL_FREQ_270MHZ;
        }

        I915_WRITE(DP_A, dpa_ctl);

        POSTING_READ(DP_A);
        udelay(500);
}

void intel_dp_set_link_params(struct intel_dp *intel_dp,
                              const struct intel_crtc_state *pipe_config)
{
        intel_dp->link_rate = pipe_config->port_clock;
        intel_dp->lane_count = pipe_config->lane_count;
}

static void intel_dp_prepare(struct intel_encoder *encoder)
{
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        enum port port = dp_to_dig_port(intel_dp)->port;
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
        const struct drm_display_mode *adjusted_mode = &crtc->config->base.adjusted_mode;

        intel_dp_set_link_params(intel_dp, crtc->config);

        /*
         * There are four kinds of DP registers:
         *
         *      IBX PCH
         *      SNB CPU
         *      IVB CPU
         *      CPT PCH
         *
         * IBX PCH and CPU are the same for almost everything,
         * except that the CPU DP PLL is configured in this
         * register
         *
         * CPT PCH is quite different, having many bits moved
         * to the TRANS_DP_CTL register instead. That
         * configuration happens (oddly) in ironlake_pch_enable
         */

        /* Preserve the BIOS-computed detected bit. This is
         * supposed to be read-only.
         */
        intel_dp->DP = I915_READ(intel_dp->output_reg) & DP_DETECTED;

        /* Handle DP bits in common between all three register formats */
        intel_dp->DP |= DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
        intel_dp->DP |= DP_PORT_WIDTH(crtc->config->lane_count);

        if (crtc->config->has_audio)
                intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;

        /* Split out the IBX/CPU vs CPT settings */

        if (IS_GEN7(dev) && port == PORT_A) {
                if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
                        intel_dp->DP |= DP_SYNC_HS_HIGH;
                if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
                        intel_dp->DP |= DP_SYNC_VS_HIGH;
                intel_dp->DP |= DP_LINK_TRAIN_OFF_CPT;

                if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
                        intel_dp->DP |= DP_ENHANCED_FRAMING;

                intel_dp->DP |= crtc->pipe << 29;
        } else if (HAS_PCH_CPT(dev) && port != PORT_A) {
                u32 trans_dp;

                intel_dp->DP |= DP_LINK_TRAIN_OFF_CPT;

                trans_dp = I915_READ(TRANS_DP_CTL(crtc->pipe));
                if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
                        trans_dp |= TRANS_DP_ENH_FRAMING;
                else
                        trans_dp &= ~TRANS_DP_ENH_FRAMING;
                I915_WRITE(TRANS_DP_CTL(crtc->pipe), trans_dp);
        } else {
                if (!HAS_PCH_SPLIT(dev) && !IS_VALLEYVIEW(dev) &&
                    crtc->config->limited_color_range)
                        intel_dp->DP |= DP_COLOR_RANGE_16_235;

                if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
                        intel_dp->DP |= DP_SYNC_HS_HIGH;
                if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
                        intel_dp->DP |= DP_SYNC_VS_HIGH;
                intel_dp->DP |= DP_LINK_TRAIN_OFF;

                if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
                        intel_dp->DP |= DP_ENHANCED_FRAMING;

                if (IS_CHERRYVIEW(dev))
                        intel_dp->DP |= DP_PIPE_SELECT_CHV(crtc->pipe);
                else if (crtc->pipe == PIPE_B)
                        intel_dp->DP |= DP_PIPEB_SELECT;
        }
}

#define IDLE_ON_MASK            (PP_ON | PP_SEQUENCE_MASK | 0                     | PP_SEQUENCE_STATE_MASK)
#define IDLE_ON_VALUE           (PP_ON | PP_SEQUENCE_NONE | 0                     | PP_SEQUENCE_STATE_ON_IDLE)

#define IDLE_OFF_MASK           (PP_ON | PP_SEQUENCE_MASK | 0                     | 0)
#define IDLE_OFF_VALUE          (0     | PP_SEQUENCE_NONE | 0                     | 0)

#define IDLE_CYCLE_MASK         (PP_ON | PP_SEQUENCE_MASK | PP_CYCLE_DELAY_ACTIVE | PP_SEQUENCE_STATE_MASK)
#define IDLE_CYCLE_VALUE        (0     | PP_SEQUENCE_NONE | 0                     | PP_SEQUENCE_STATE_OFF_IDLE)

static void wait_panel_status(struct intel_dp *intel_dp,
                                       u32 mask,
                                       u32 value)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pp_stat_reg, pp_ctrl_reg;

        lockdep_assert_held(&dev_priv->pps_mutex);

        pp_stat_reg = _pp_stat_reg(intel_dp);
        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);

        DRM_DEBUG_KMS("mask %08x value %08x status %08x control %08x\n",
                        mask, value,
                        I915_READ(pp_stat_reg),
                        I915_READ(pp_ctrl_reg));

        if (_wait_for((I915_READ(pp_stat_reg) & mask) == value, 5000, 10)) {
                DRM_ERROR("Panel status timeout: status %08x control %08x\n",
                                I915_READ(pp_stat_reg),
                                I915_READ(pp_ctrl_reg));
        }

        DRM_DEBUG_KMS("Wait complete\n");
}

static void wait_panel_on(struct intel_dp *intel_dp)
{
        DRM_DEBUG_KMS("Wait for panel power on\n");
        wait_panel_status(intel_dp, IDLE_ON_MASK, IDLE_ON_VALUE);
}

static void wait_panel_off(struct intel_dp *intel_dp)
{
        DRM_DEBUG_KMS("Wait for panel power off time\n");
        wait_panel_status(intel_dp, IDLE_OFF_MASK, IDLE_OFF_VALUE);
}

static void wait_panel_power_cycle(struct intel_dp *intel_dp)
{
        DRM_DEBUG_KMS("Wait for panel power cycle\n");

        /* When we disable the VDD override bit last we have to do the manual
         * wait. */
        wait_remaining_ms_from_jiffies(intel_dp->last_power_cycle,
                                       intel_dp->panel_power_cycle_delay);

        wait_panel_status(intel_dp, IDLE_CYCLE_MASK, IDLE_CYCLE_VALUE);
}

static void wait_backlight_on(struct intel_dp *intel_dp)
{
        wait_remaining_ms_from_jiffies(intel_dp->last_power_on,
                                       intel_dp->backlight_on_delay);
}

static void edp_wait_backlight_off(struct intel_dp *intel_dp)
{
        wait_remaining_ms_from_jiffies(intel_dp->last_backlight_off,
                                       intel_dp->backlight_off_delay);
}

/* Read the current pp_control value, unlocking the register if it
 * is locked
 */

static  u32 ironlake_get_pp_control(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 control;

        lockdep_assert_held(&dev_priv->pps_mutex);

        control = I915_READ(_pp_ctrl_reg(intel_dp));
        if (!IS_BROXTON(dev)) {
                control &= ~PANEL_UNLOCK_MASK;
                control |= PANEL_UNLOCK_REGS;
        }
        return control;
}

/*
 * Must be paired with edp_panel_vdd_off().
 * Must hold pps_mutex around the whole on/off sequence.
 * Can be nested with intel_edp_panel_vdd_{on,off}() calls.
 */
static bool edp_panel_vdd_on(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;
        u32 pp;
        u32 pp_stat_reg, pp_ctrl_reg;
        bool need_to_disable = !intel_dp->want_panel_vdd;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!is_edp(intel_dp))
                return false;

        cancel_delayed_work(&intel_dp->panel_vdd_work);
        intel_dp->want_panel_vdd = true;

        if (edp_have_panel_vdd(intel_dp))
                return need_to_disable;

        power_domain = intel_display_port_power_domain(intel_encoder);
        intel_display_power_get(dev_priv, power_domain);

        DRM_DEBUG_KMS("Turning eDP port %c VDD on\n",
                      port_name(intel_dig_port->port));

        if (!edp_have_panel_power(intel_dp))
                wait_panel_power_cycle(intel_dp);

        pp = ironlake_get_pp_control(intel_dp);
        pp |= EDP_FORCE_VDD;

        pp_stat_reg = _pp_stat_reg(intel_dp);
        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);
        DRM_DEBUG_KMS("PP_STATUS: 0x%08x PP_CONTROL: 0x%08x\n",
                        I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));
        /*
         * If the panel wasn't on, delay before accessing aux channel
         */
        if (!edp_have_panel_power(intel_dp)) {
                DRM_DEBUG_KMS("eDP port %c panel power wasn't enabled\n",
                              port_name(intel_dig_port->port));
                msleep(intel_dp->panel_power_up_delay);
        }

        return need_to_disable;
}

/*
 * Must be paired with intel_edp_panel_vdd_off() or
 * intel_edp_panel_off().
 * Nested calls to these functions are not allowed since
 * we drop the lock. Caller must use some higher level
 * locking to prevent nested calls from other threads.
 */
void intel_edp_panel_vdd_on(struct intel_dp *intel_dp)
{
        bool vdd;

        if (!is_edp(intel_dp))
                return;

        pps_lock(intel_dp);
        vdd = edp_panel_vdd_on(intel_dp);
        pps_unlock(intel_dp);

        I915_STATE_WARN(!vdd, "eDP port %c VDD already requested on\n",
             port_name(dp_to_dig_port(intel_dp)->port));
}

static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *intel_dig_port =
                dp_to_dig_port(intel_dp);
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        enum intel_display_power_domain power_domain;
        u32 pp;
        u32 pp_stat_reg, pp_ctrl_reg;

        lockdep_assert_held(&dev_priv->pps_mutex);

        WARN_ON(intel_dp->want_panel_vdd);

        if (!edp_have_panel_vdd(intel_dp))
                return;

        DRM_DEBUG_KMS("Turning eDP port %c VDD off\n",
                      port_name(intel_dig_port->port));

        pp = ironlake_get_pp_control(intel_dp);
        pp &= ~EDP_FORCE_VDD;

        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
        pp_stat_reg = _pp_stat_reg(intel_dp);

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);

        /* Make sure sequencer is idle before allowing subsequent activity */
        DRM_DEBUG_KMS("PP_STATUS: 0x%08x PP_CONTROL: 0x%08x\n",
        I915_READ(pp_stat_reg), I915_READ(pp_ctrl_reg));

        if ((pp & POWER_TARGET_ON) == 0)
                intel_dp->last_power_cycle = jiffies;

        power_domain = intel_display_port_power_domain(intel_encoder);
        intel_display_power_put(dev_priv, power_domain);
}

static void edp_panel_vdd_work(struct work_struct *__work)
{
        struct intel_dp *intel_dp = container_of(to_delayed_work(__work),
                                                 struct intel_dp, panel_vdd_work);

        pps_lock(intel_dp);
        if (!intel_dp->want_panel_vdd)
                edp_panel_vdd_off_sync(intel_dp);
        pps_unlock(intel_dp);
}

static void edp_panel_vdd_schedule_off(struct intel_dp *intel_dp)
{
        unsigned long delay;

        /*
         * Queue the timer to fire a long time from now (relative to the power
         * down delay) to keep the panel power up across a sequence of
         * operations.
         */
        delay = msecs_to_jiffies(intel_dp->panel_power_cycle_delay * 5);
        schedule_delayed_work(&intel_dp->panel_vdd_work, delay);
}

/*
 * Must be paired with edp_panel_vdd_on().
 * Must hold pps_mutex around the whole on/off sequence.
 * Can be nested with intel_edp_panel_vdd_{on,off}() calls.
 */
static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync)
{
        struct drm_i915_private *dev_priv =
                intel_dp_to_dev(intel_dp)->dev_private;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!is_edp(intel_dp))
                return;

        I915_STATE_WARN(!intel_dp->want_panel_vdd, "eDP port %c VDD not forced on",
             port_name(dp_to_dig_port(intel_dp)->port));

        intel_dp->want_panel_vdd = false;

        if (sync)
                edp_panel_vdd_off_sync(intel_dp);
        else
                edp_panel_vdd_schedule_off(intel_dp);
}

static void edp_panel_on(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pp;
        u32 pp_ctrl_reg;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!is_edp(intel_dp))
                return;

        DRM_DEBUG_KMS("Turn eDP port %c panel power on\n",
                      port_name(dp_to_dig_port(intel_dp)->port));

        if (WARN(edp_have_panel_power(intel_dp),
                 "eDP port %c panel power already on\n",
                 port_name(dp_to_dig_port(intel_dp)->port)))
                return;

        wait_panel_power_cycle(intel_dp);

        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);
        pp = ironlake_get_pp_control(intel_dp);
        if (IS_GEN5(dev)) {
                /* ILK workaround: disable reset around power sequence */
                pp &= ~PANEL_POWER_RESET;
                I915_WRITE(pp_ctrl_reg, pp);
                POSTING_READ(pp_ctrl_reg);
        }

        pp |= POWER_TARGET_ON;
        if (!IS_GEN5(dev))
                pp |= PANEL_POWER_RESET;

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);

        wait_panel_on(intel_dp);
        intel_dp->last_power_on = jiffies;

        if (IS_GEN5(dev)) {
                pp |= PANEL_POWER_RESET; /* restore panel reset bit */
                I915_WRITE(pp_ctrl_reg, pp);
                POSTING_READ(pp_ctrl_reg);
        }
}

void intel_edp_panel_on(struct intel_dp *intel_dp)
{
        if (!is_edp(intel_dp))
                return;

        pps_lock(intel_dp);
        edp_panel_on(intel_dp);
        pps_unlock(intel_dp);
}


static void edp_panel_off(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;
        u32 pp;
        u32 pp_ctrl_reg;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!is_edp(intel_dp))
                return;

        DRM_DEBUG_KMS("Turn eDP port %c panel power off\n",
                      port_name(dp_to_dig_port(intel_dp)->port));

        WARN(!intel_dp->want_panel_vdd, "Need eDP port %c VDD to turn off panel\n",
             port_name(dp_to_dig_port(intel_dp)->port));

        pp = ironlake_get_pp_control(intel_dp);
        /* We need to switch off panel power _and_ force vdd, for otherwise some
         * panels get very unhappy and cease to work. */
        pp &= ~(POWER_TARGET_ON | PANEL_POWER_RESET | EDP_FORCE_VDD |
                EDP_BLC_ENABLE);

        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);

        intel_dp->want_panel_vdd = false;

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);

        intel_dp->last_power_cycle = jiffies;
        wait_panel_off(intel_dp);

        /* We got a reference when we enabled the VDD. */
        power_domain = intel_display_port_power_domain(intel_encoder);
        intel_display_power_put(dev_priv, power_domain);
}

void intel_edp_panel_off(struct intel_dp *intel_dp)
{
        if (!is_edp(intel_dp))
                return;

        pps_lock(intel_dp);
        edp_panel_off(intel_dp);
        pps_unlock(intel_dp);
}

/* Enable backlight in the panel power control. */
static void _intel_edp_backlight_on(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pp;
        u32 pp_ctrl_reg;

        /*
         * If we enable the backlight right away following a panel power
         * on, we may see slight flicker as the panel syncs with the eDP
         * link.  So delay a bit to make sure the image is solid before
         * allowing it to appear.
         */
        wait_backlight_on(intel_dp);

        pps_lock(intel_dp);

        pp = ironlake_get_pp_control(intel_dp);
        pp |= EDP_BLC_ENABLE;

        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);

        pps_unlock(intel_dp);
}

/* Enable backlight PWM and backlight PP control. */
void intel_edp_backlight_on(struct intel_dp *intel_dp)
{
        if (!is_edp(intel_dp))
                return;

        DRM_DEBUG_KMS("\n");

        intel_panel_enable_backlight(intel_dp->attached_connector);
        _intel_edp_backlight_on(intel_dp);
}

/* Disable backlight in the panel power control. */
static void _intel_edp_backlight_off(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pp;
        u32 pp_ctrl_reg;

        if (!is_edp(intel_dp))
                return;

        pps_lock(intel_dp);

        pp = ironlake_get_pp_control(intel_dp);
        pp &= ~EDP_BLC_ENABLE;

        pp_ctrl_reg = _pp_ctrl_reg(intel_dp);

        I915_WRITE(pp_ctrl_reg, pp);
        POSTING_READ(pp_ctrl_reg);

        pps_unlock(intel_dp);

        intel_dp->last_backlight_off = jiffies;
        edp_wait_backlight_off(intel_dp);
}

/* Disable backlight PP control and backlight PWM. */
void intel_edp_backlight_off(struct intel_dp *intel_dp)
{
        if (!is_edp(intel_dp))
                return;

        DRM_DEBUG_KMS("\n");

        _intel_edp_backlight_off(intel_dp);
        intel_panel_disable_backlight(intel_dp->attached_connector);
}

/*
 * Hook for controlling the panel power control backlight through the bl_power
 * sysfs attribute. Take care to handle multiple calls.
 */
static void intel_edp_backlight_power(struct intel_connector *connector,
                                      bool enable)
{
        struct intel_dp *intel_dp = intel_attached_dp(&connector->base);
        bool is_enabled;

        pps_lock(intel_dp);
        is_enabled = ironlake_get_pp_control(intel_dp) & EDP_BLC_ENABLE;
        pps_unlock(intel_dp);

        if (is_enabled == enable)
                return;

        DRM_DEBUG_KMS("panel power control backlight %s\n",
                      enable ? "enable" : "disable");

        if (enable)
                _intel_edp_backlight_on(intel_dp);
        else
                _intel_edp_backlight_off(intel_dp);
}

static void ironlake_edp_pll_on(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_crtc *crtc = intel_dig_port->base.base.crtc;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dpa_ctl;

        assert_pipe_disabled(dev_priv,
                             to_intel_crtc(crtc)->pipe);

        DRM_DEBUG_KMS("\n");
        dpa_ctl = I915_READ(DP_A);
        WARN(dpa_ctl & DP_PLL_ENABLE, "dp pll on, should be off\n");
        WARN(dpa_ctl & DP_PORT_EN, "dp port still on, should be off\n");

        /* We don't adjust intel_dp->DP while tearing down the link, to
         * facilitate link retraining (e.g. after hotplug). Hence clear all
         * enable bits here to ensure that we don't enable too much. */
        intel_dp->DP &= ~(DP_PORT_EN | DP_AUDIO_OUTPUT_ENABLE);
        intel_dp->DP |= DP_PLL_ENABLE;
        I915_WRITE(DP_A, intel_dp->DP);
        POSTING_READ(DP_A);
        udelay(200);
}

static void ironlake_edp_pll_off(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_crtc *crtc = intel_dig_port->base.base.crtc;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 dpa_ctl;

        assert_pipe_disabled(dev_priv,
                             to_intel_crtc(crtc)->pipe);

        dpa_ctl = I915_READ(DP_A);
        WARN((dpa_ctl & DP_PLL_ENABLE) == 0,
             "dp pll off, should be on\n");
        WARN(dpa_ctl & DP_PORT_EN, "dp port still on, should be off\n");

        /* We can't rely on the value tracked for the DP register in
         * intel_dp->DP because link_down must not change that (otherwise link
         * re-training will fail. */
        dpa_ctl &= ~DP_PLL_ENABLE;
        I915_WRITE(DP_A, dpa_ctl);
        POSTING_READ(DP_A);
        udelay(200);
}

/* If the sink supports it, try to set the power state appropriately */
void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
{
        int ret, i;

        /* Should have a valid DPCD by this point */
        if (intel_dp->dpcd[DP_DPCD_REV] < 0x11)
                return;

        if (mode != DRM_MODE_DPMS_ON) {
                ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
                                         DP_SET_POWER_D3);
        } else {
                /*
                 * When turning on, we need to retry for 1ms to give the sink
                 * time to wake up.
                 */
                for (i = 0; i < 3; i++) {
                        ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
                                                 DP_SET_POWER_D0);
                        if (ret == 1)
                                break;
                        msleep(1);
                }
        }

        if (ret != 1)
                DRM_DEBUG_KMS("failed to %s sink power state\n",
                              mode == DRM_MODE_DPMS_ON ? "enable" : "disable");
}

static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
                                  enum pipe *pipe)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        enum port port = dp_to_dig_port(intel_dp)->port;
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;
        u32 tmp;

        power_domain = intel_display_port_power_domain(encoder);
        if (!intel_display_power_is_enabled(dev_priv, power_domain))
                return false;

        tmp = I915_READ(intel_dp->output_reg);

        if (!(tmp & DP_PORT_EN))
                return false;

        if (IS_GEN7(dev) && port == PORT_A) {
                *pipe = PORT_TO_PIPE_CPT(tmp);
        } else if (HAS_PCH_CPT(dev) && port != PORT_A) {
                enum pipe p;

                for_each_pipe(dev_priv, p) {
                        u32 trans_dp = I915_READ(TRANS_DP_CTL(p));
                        if (TRANS_DP_PIPE_TO_PORT(trans_dp) == port) {
                                *pipe = p;
                                return true;
                        }
                }

                DRM_DEBUG_KMS("No pipe for dp port 0x%x found\n",
                              intel_dp->output_reg);
        } else if (IS_CHERRYVIEW(dev)) {
                *pipe = DP_PORT_TO_PIPE_CHV(tmp);
        } else {
                *pipe = PORT_TO_PIPE(tmp);
        }

        return true;
}

static void intel_dp_get_config(struct intel_encoder *encoder,
                                struct intel_crtc_state *pipe_config)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        u32 tmp, flags = 0;
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = dp_to_dig_port(intel_dp)->port;
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
        int dotclock;

        tmp = I915_READ(intel_dp->output_reg);

        pipe_config->has_audio = tmp & DP_AUDIO_OUTPUT_ENABLE && port != PORT_A;

        if (HAS_PCH_CPT(dev) && port != PORT_A) {
                u32 trans_dp = I915_READ(TRANS_DP_CTL(crtc->pipe));

                if (trans_dp & TRANS_DP_HSYNC_ACTIVE_HIGH)
                        flags |= DRM_MODE_FLAG_PHSYNC;
                else
                        flags |= DRM_MODE_FLAG_NHSYNC;

                if (trans_dp & TRANS_DP_VSYNC_ACTIVE_HIGH)
                        flags |= DRM_MODE_FLAG_PVSYNC;
                else
                        flags |= DRM_MODE_FLAG_NVSYNC;
        } else {
                if (tmp & DP_SYNC_HS_HIGH)
                        flags |= DRM_MODE_FLAG_PHSYNC;
                else
                        flags |= DRM_MODE_FLAG_NHSYNC;

                if (tmp & DP_SYNC_VS_HIGH)
                        flags |= DRM_MODE_FLAG_PVSYNC;
                else
                        flags |= DRM_MODE_FLAG_NVSYNC;
        }

        pipe_config->base.adjusted_mode.flags |= flags;

        if (!HAS_PCH_SPLIT(dev) && !IS_VALLEYVIEW(dev) &&
            tmp & DP_COLOR_RANGE_16_235)
                pipe_config->limited_color_range = true;

        pipe_config->has_dp_encoder = true;

        pipe_config->lane_count =
                ((tmp & DP_PORT_WIDTH_MASK) >> DP_PORT_WIDTH_SHIFT) + 1;

        intel_dp_get_m_n(crtc, pipe_config);

        if (port == PORT_A) {
                if ((I915_READ(DP_A) & DP_PLL_FREQ_MASK) == DP_PLL_FREQ_160MHZ)
                        pipe_config->port_clock = 162000;
                else
                        pipe_config->port_clock = 270000;
        }

        dotclock = intel_dotclock_calculate(pipe_config->port_clock,
                                            &pipe_config->dp_m_n);

        if (HAS_PCH_SPLIT(dev_priv->dev) && port != PORT_A)
                ironlake_check_encoder_dotclock(pipe_config, dotclock);

        pipe_config->base.adjusted_mode.crtc_clock = dotclock;

        if (is_edp(intel_dp) && dev_priv->vbt.edp_bpp &&
            pipe_config->pipe_bpp > dev_priv->vbt.edp_bpp) {
                /*
                 * This is a big fat ugly hack.
                 *
                 * Some machines in UEFI boot mode provide us a VBT that has 18
                 * bpp and 1.62 GHz link bandwidth for eDP, which for reasons
                 * unknown we fail to light up. Yet the same BIOS boots up with
                 * 24 bpp and 2.7 GHz link. Use the same bpp as the BIOS uses as
                 * max, not what it tells us to use.
                 *
                 * Note: This will still be broken if the eDP panel is not lit
                 * up by the BIOS, and thus we can't get the mode at module
                 * load.
                 */
                DRM_DEBUG_KMS("pipe has %d bpp for eDP panel, overriding BIOS-provided max %d bpp\n",
                              pipe_config->pipe_bpp, dev_priv->vbt.edp_bpp);
                dev_priv->vbt.edp_bpp = pipe_config->pipe_bpp;
        }
}

static void intel_disable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct drm_device *dev = encoder->base.dev;
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);

        if (crtc->config->has_audio)
                intel_audio_codec_disable(encoder);

        if (HAS_PSR(dev) && !HAS_DDI(dev))
                intel_psr_disable(intel_dp);

        /* Make sure the panel is off before trying to change the mode. But also
         * ensure that we have vdd while we switch off the panel. */
        intel_edp_panel_vdd_on(intel_dp);
        intel_edp_backlight_off(intel_dp);
        intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
        intel_edp_panel_off(intel_dp);

        /* disable the port before the pipe on g4x */
        if (INTEL_INFO(dev)->gen < 5)
                intel_dp_link_down(intel_dp);
}

static void ilk_post_disable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        enum port port = dp_to_dig_port(intel_dp)->port;

        intel_dp_link_down(intel_dp);
        if (port == PORT_A)
                ironlake_edp_pll_off(intel_dp);
}

static void vlv_post_disable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);

        intel_dp_link_down(intel_dp);
}

static void chv_data_lane_soft_reset(struct intel_encoder *encoder,
                                     bool reset)
{
        struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
        enum dpio_channel ch = vlv_dport_to_channel(enc_to_dig_port(&encoder->base));
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
        enum pipe pipe = crtc->pipe;
        uint32_t val;

        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
        if (reset)
                val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
        else
                val |= DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);

        if (crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
                if (reset)
                        val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
                else
                        val |= DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
        }

        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
        val |= CHV_PCS_REQ_SOFTRESET_EN;
        if (reset)
                val &= ~DPIO_PCS_CLK_SOFT_RESET;
        else
                val |= DPIO_PCS_CLK_SOFT_RESET;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW1(ch), val);

        if (crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW1(ch));
                val |= CHV_PCS_REQ_SOFTRESET_EN;
                if (reset)
                        val &= ~DPIO_PCS_CLK_SOFT_RESET;
                else
                        val |= DPIO_PCS_CLK_SOFT_RESET;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW1(ch), val);
        }
}

static void chv_post_disable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;

        intel_dp_link_down(intel_dp);

        mutex_lock(&dev_priv->sb_lock);

        /* Assert data lane reset */
        chv_data_lane_soft_reset(encoder, true);

        mutex_unlock(&dev_priv->sb_lock);
}

static void
_intel_dp_set_link_train(struct intel_dp *intel_dp,
                         uint32_t *DP,
                         uint8_t dp_train_pat)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = intel_dig_port->port;

        if (HAS_DDI(dev)) {
                uint32_t temp = I915_READ(DP_TP_CTL(port));

                if (dp_train_pat & DP_LINK_SCRAMBLING_DISABLE)
                        temp |= DP_TP_CTL_SCRAMBLE_DISABLE;
                else
                        temp &= ~DP_TP_CTL_SCRAMBLE_DISABLE;

                temp &= ~DP_TP_CTL_LINK_TRAIN_MASK;
                switch (dp_train_pat & DP_TRAINING_PATTERN_MASK) {
                case DP_TRAINING_PATTERN_DISABLE:
                        temp |= DP_TP_CTL_LINK_TRAIN_NORMAL;

                        break;
                case DP_TRAINING_PATTERN_1:
                        temp |= DP_TP_CTL_LINK_TRAIN_PAT1;
                        break;
                case DP_TRAINING_PATTERN_2:
                        temp |= DP_TP_CTL_LINK_TRAIN_PAT2;
                        break;
                case DP_TRAINING_PATTERN_3:
                        temp |= DP_TP_CTL_LINK_TRAIN_PAT3;
                        break;
                }
                I915_WRITE(DP_TP_CTL(port), temp);

        } else if ((IS_GEN7(dev) && port == PORT_A) ||
                   (HAS_PCH_CPT(dev) && port != PORT_A)) {
                *DP &= ~DP_LINK_TRAIN_MASK_CPT;

                switch (dp_train_pat & DP_TRAINING_PATTERN_MASK) {
                case DP_TRAINING_PATTERN_DISABLE:
                        *DP |= DP_LINK_TRAIN_OFF_CPT;
                        break;
                case DP_TRAINING_PATTERN_1:
                        *DP |= DP_LINK_TRAIN_PAT_1_CPT;
                        break;
                case DP_TRAINING_PATTERN_2:
                        *DP |= DP_LINK_TRAIN_PAT_2_CPT;
                        break;
                case DP_TRAINING_PATTERN_3:
                        DRM_ERROR("DP training pattern 3 not supported\n");
                        *DP |= DP_LINK_TRAIN_PAT_2_CPT;
                        break;
                }

        } else {
                if (IS_CHERRYVIEW(dev))
                        *DP &= ~DP_LINK_TRAIN_MASK_CHV;
                else
                        *DP &= ~DP_LINK_TRAIN_MASK;

                switch (dp_train_pat & DP_TRAINING_PATTERN_MASK) {
                case DP_TRAINING_PATTERN_DISABLE:
                        *DP |= DP_LINK_TRAIN_OFF;
                        break;
                case DP_TRAINING_PATTERN_1:
                        *DP |= DP_LINK_TRAIN_PAT_1;
                        break;
                case DP_TRAINING_PATTERN_2:
                        *DP |= DP_LINK_TRAIN_PAT_2;
                        break;
                case DP_TRAINING_PATTERN_3:
                        if (IS_CHERRYVIEW(dev)) {
                                *DP |= DP_LINK_TRAIN_PAT_3_CHV;
                        } else {
                                DRM_ERROR("DP training pattern 3 not supported\n");
                                *DP |= DP_LINK_TRAIN_PAT_2;
                        }
                        break;
                }
        }
}

static void intel_dp_enable_port(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;

        /* enable with pattern 1 (as per spec) */
        _intel_dp_set_link_train(intel_dp, &intel_dp->DP,
                                 DP_TRAINING_PATTERN_1);

        I915_WRITE(intel_dp->output_reg, intel_dp->DP);
        POSTING_READ(intel_dp->output_reg);

        /*
         * Magic for VLV/CHV. We _must_ first set up the register
         * without actually enabling the port, and then do another
         * write to enable the port. Otherwise link training will
         * fail when the power sequencer is freshly used for this port.
         */
        intel_dp->DP |= DP_PORT_EN;

        I915_WRITE(intel_dp->output_reg, intel_dp->DP);
        POSTING_READ(intel_dp->output_reg);
}

static void intel_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
        uint32_t dp_reg = I915_READ(intel_dp->output_reg);

        if (WARN_ON(dp_reg & DP_PORT_EN))
                return;

        pps_lock(intel_dp);

        if (IS_VALLEYVIEW(dev))
                vlv_init_panel_power_sequencer(intel_dp);

        intel_dp_enable_port(intel_dp);

        edp_panel_vdd_on(intel_dp);
        edp_panel_on(intel_dp);
        edp_panel_vdd_off(intel_dp, true);

        pps_unlock(intel_dp);

        if (IS_VALLEYVIEW(dev)) {
                unsigned int lane_mask = 0x0;

                if (IS_CHERRYVIEW(dev))
                        lane_mask = intel_dp_unused_lane_mask(crtc->config->lane_count);

                vlv_wait_port_ready(dev_priv, dp_to_dig_port(intel_dp),
                                    lane_mask);
        }

        intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
        intel_dp_start_link_train(intel_dp);
        intel_dp_stop_link_train(intel_dp);

        if (crtc->config->has_audio) {
                DRM_DEBUG_DRIVER("Enabling DP audio on pipe %c\n",
                                 pipe_name(crtc->pipe));
                intel_audio_codec_enable(encoder);
        }
}

static void g4x_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);

        intel_enable_dp(encoder);
        intel_edp_backlight_on(intel_dp);
}

static void vlv_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);

        intel_edp_backlight_on(intel_dp);
        intel_psr_enable(intel_dp);
}

static void g4x_pre_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct intel_digital_port *dport = dp_to_dig_port(intel_dp);

        intel_dp_prepare(encoder);

        /* Only ilk+ has port A */
        if (dport->port == PORT_A) {
                ironlake_set_pll_cpu_edp(intel_dp);
                ironlake_edp_pll_on(intel_dp);
        }
}

static void vlv_detach_power_sequencer(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv = intel_dig_port->base.base.dev->dev_private;
        enum pipe pipe = intel_dp->pps_pipe;
        int pp_on_reg = VLV_PIPE_PP_ON_DELAYS(pipe);

        edp_panel_vdd_off_sync(intel_dp);

        /*
         * VLV seems to get confused when multiple power seqeuencers
         * have the same port selected (even if only one has power/vdd
         * enabled). The failure manifests as vlv_wait_port_ready() failing
         * CHV on the other hand doesn't seem to mind having the same port
         * selected in multiple power seqeuencers, but let's clear the
         * port select always when logically disconnecting a power sequencer
         * from a port.
         */
        DRM_DEBUG_KMS("detaching pipe %c power sequencer from port %c\n",
                      pipe_name(pipe), port_name(intel_dig_port->port));
        I915_WRITE(pp_on_reg, 0);
        POSTING_READ(pp_on_reg);

        intel_dp->pps_pipe = INVALID_PIPE;
}

static void vlv_steal_power_sequencer(struct drm_device *dev,
                                      enum pipe pipe)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_encoder *encoder;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
                return;

        list_for_each_entry(encoder, &dev->mode_config.encoder_list,
                            base.head) {
                struct intel_dp *intel_dp;
                enum port port;

                if (encoder->type != INTEL_OUTPUT_EDP)
                        continue;

                intel_dp = enc_to_intel_dp(&encoder->base);
                port = dp_to_dig_port(intel_dp)->port;

                if (intel_dp->pps_pipe != pipe)
                        continue;

                DRM_DEBUG_KMS("stealing pipe %c power sequencer from port %c\n",
                              pipe_name(pipe), port_name(port));

                WARN(encoder->base.crtc,
                     "stealing pipe %c power sequencer from active eDP port %c\n",
                     pipe_name(pipe), port_name(port));

                /* make sure vdd is off before we steal it */
                vlv_detach_power_sequencer(intel_dp);
        }
}

static void vlv_init_panel_power_sequencer(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *encoder = &intel_dig_port->base;
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!is_edp(intel_dp))
                return;

        if (intel_dp->pps_pipe == crtc->pipe)
                return;

        /*
         * If another power sequencer was being used on this
         * port previously make sure to turn off vdd there while
         * we still have control of it.
         */
        if (intel_dp->pps_pipe != INVALID_PIPE)
                vlv_detach_power_sequencer(intel_dp);

        /*
         * We may be stealing the power
         * sequencer from another port.
         */
        vlv_steal_power_sequencer(dev, crtc->pipe);

        /* now it's all ours */
        intel_dp->pps_pipe = crtc->pipe;

        DRM_DEBUG_KMS("initializing pipe %c power sequencer for port %c\n",
                      pipe_name(intel_dp->pps_pipe), port_name(intel_dig_port->port));

        /* init power sequencer on this pipe and port */
        intel_dp_init_panel_power_sequencer(dev, intel_dp);
        intel_dp_init_panel_power_sequencer_registers(dev, intel_dp);
}

static void vlv_pre_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
        enum dpio_channel port = vlv_dport_to_channel(dport);
        int pipe = intel_crtc->pipe;
        u32 val;

        mutex_lock(&dev_priv->sb_lock);

        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW8(port));
        val = 0;
        if (pipe)
                val |= (1<<21);
        else
                val &= ~(1<<21);
        val |= 0x001000c4;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW8(port), val);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW14(port), 0x00760018);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW23(port), 0x00400888);

        mutex_unlock(&dev_priv->sb_lock);

        intel_enable_dp(encoder);
}

static void vlv_dp_pre_pll_enable(struct intel_encoder *encoder)
{
        struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *intel_crtc =
                to_intel_crtc(encoder->base.crtc);
        enum dpio_channel port = vlv_dport_to_channel(dport);
        int pipe = intel_crtc->pipe;

        intel_dp_prepare(encoder);

        /* Program Tx lane resets to default */
        mutex_lock(&dev_priv->sb_lock);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW0(port),
                         DPIO_PCS_TX_LANE2_RESET |
                         DPIO_PCS_TX_LANE1_RESET);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW1(port),
                         DPIO_PCS_CLK_CRI_RXEB_EIOS_EN |
                         DPIO_PCS_CLK_CRI_RXDIGFILTSG_EN |
                         (1<<DPIO_PCS_CLK_DATAWIDTH_SHIFT) |
                                 DPIO_PCS_CLK_SOFT_RESET);

        /* Fix up inter-pair skew failure */
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW12(port), 0x00750f00);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW11(port), 0x00001500);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW14(port), 0x40400000);
        mutex_unlock(&dev_priv->sb_lock);
}

static void chv_pre_enable_dp(struct intel_encoder *encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
        struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *intel_crtc =
                to_intel_crtc(encoder->base.crtc);
        enum dpio_channel ch = vlv_dport_to_channel(dport);
        int pipe = intel_crtc->pipe;
        int data, i, stagger;
        u32 val;

        mutex_lock(&dev_priv->sb_lock);

        /* allow hardware to manage TX FIFO reset source */
        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
        val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
                val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
        }

        /* Program Tx lane latency optimal setting*/
        for (i = 0; i < intel_crtc->config->lane_count; i++) {
                /* Set the upar bit */
                if (intel_crtc->config->lane_count == 1)
                        data = 0x0;
                else
                        data = (i == 1) ? 0x0 : 0x1;
                vlv_dpio_write(dev_priv, pipe, CHV_TX_DW14(ch, i),
                                data << DPIO_UPAR_SHIFT);
        }

        /* Data lane stagger programming */
        if (intel_crtc->config->port_clock > 270000)
                stagger = 0x18;
        else if (intel_crtc->config->port_clock > 135000)
                stagger = 0xd;
        else if (intel_crtc->config->port_clock > 67500)
                stagger = 0x7;
        else if (intel_crtc->config->port_clock > 33750)
                stagger = 0x4;
        else
                stagger = 0x2;

        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
        val |= DPIO_TX2_STAGGER_MASK(0x1f);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
                val |= DPIO_TX2_STAGGER_MASK(0x1f);
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
        }

        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW12(ch),
                       DPIO_LANESTAGGER_STRAP(stagger) |
                       DPIO_LANESTAGGER_STRAP_OVRD |
                       DPIO_TX1_STAGGER_MASK(0x1f) |
                       DPIO_TX1_STAGGER_MULT(6) |
                       DPIO_TX2_STAGGER_MULT(0));

        if (intel_crtc->config->lane_count > 2) {
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW12(ch),
                               DPIO_LANESTAGGER_STRAP(stagger) |
                               DPIO_LANESTAGGER_STRAP_OVRD |
                               DPIO_TX1_STAGGER_MASK(0x1f) |
                               DPIO_TX1_STAGGER_MULT(7) |
                               DPIO_TX2_STAGGER_MULT(5));
        }

        /* Deassert data lane reset */
        chv_data_lane_soft_reset(encoder, false);

        mutex_unlock(&dev_priv->sb_lock);

        intel_enable_dp(encoder);

        /* Second common lane will stay alive on its own now */
        if (dport->release_cl2_override) {
                chv_phy_powergate_ch(dev_priv, DPIO_PHY0, DPIO_CH1, false);
                dport->release_cl2_override = false;
        }
}

static void chv_dp_pre_pll_enable(struct intel_encoder *encoder)
{
        struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
        struct drm_device *dev = encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_crtc *intel_crtc =
                to_intel_crtc(encoder->base.crtc);
        enum dpio_channel ch = vlv_dport_to_channel(dport);
        enum pipe pipe = intel_crtc->pipe;
        unsigned int lane_mask =
                intel_dp_unused_lane_mask(intel_crtc->config->lane_count);
        u32 val;

        intel_dp_prepare(encoder);

        /*
         * Must trick the second common lane into life.
         * Otherwise we can't even access the PLL.
         */
        if (ch == DPIO_CH0 && pipe == PIPE_B)
                dport->release_cl2_override =
                        !chv_phy_powergate_ch(dev_priv, DPIO_PHY0, DPIO_CH1, true);

        chv_phy_powergate_lanes(encoder, true, lane_mask);

        mutex_lock(&dev_priv->sb_lock);

        /* Assert data lane reset */
        chv_data_lane_soft_reset(encoder, true);

        /* program left/right clock distribution */
        if (pipe != PIPE_B) {
                val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW5_CH0);
                val &= ~(CHV_BUFLEFTENA1_MASK | CHV_BUFRIGHTENA1_MASK);
                if (ch == DPIO_CH0)
                        val |= CHV_BUFLEFTENA1_FORCE;
                if (ch == DPIO_CH1)
                        val |= CHV_BUFRIGHTENA1_FORCE;
                vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW5_CH0, val);
        } else {
                val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW1_CH1);
                val &= ~(CHV_BUFLEFTENA2_MASK | CHV_BUFRIGHTENA2_MASK);
                if (ch == DPIO_CH0)
                        val |= CHV_BUFLEFTENA2_FORCE;
                if (ch == DPIO_CH1)
                        val |= CHV_BUFRIGHTENA2_FORCE;
                vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW1_CH1, val);
        }

        /* program clock channel usage */
        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW8(ch));
        val |= CHV_PCS_USEDCLKCHANNEL_OVRRIDE;
        if (pipe != PIPE_B)
                val &= ~CHV_PCS_USEDCLKCHANNEL;
        else
                val |= CHV_PCS_USEDCLKCHANNEL;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW8(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW8(ch));
                val |= CHV_PCS_USEDCLKCHANNEL_OVRRIDE;
                if (pipe != PIPE_B)
                        val &= ~CHV_PCS_USEDCLKCHANNEL;
                else
                        val |= CHV_PCS_USEDCLKCHANNEL;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW8(ch), val);
        }

        /*
         * This a a bit weird since generally CL
         * matches the pipe, but here we need to
         * pick the CL based on the port.
         */
        val = vlv_dpio_read(dev_priv, pipe, CHV_CMN_DW19(ch));
        if (pipe != PIPE_B)
                val &= ~CHV_CMN_USEDCLKCHANNEL;
        else
                val |= CHV_CMN_USEDCLKCHANNEL;
        vlv_dpio_write(dev_priv, pipe, CHV_CMN_DW19(ch), val);

        mutex_unlock(&dev_priv->sb_lock);
}

static void chv_dp_post_pll_disable(struct intel_encoder *encoder)
{
        struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
        enum pipe pipe = to_intel_crtc(encoder->base.crtc)->pipe;
        u32 val;

        mutex_lock(&dev_priv->sb_lock);

        /* disable left/right clock distribution */
        if (pipe != PIPE_B) {
                val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW5_CH0);
                val &= ~(CHV_BUFLEFTENA1_MASK | CHV_BUFRIGHTENA1_MASK);
                vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW5_CH0, val);
        } else {
                val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW1_CH1);
                val &= ~(CHV_BUFLEFTENA2_MASK | CHV_BUFRIGHTENA2_MASK);
                vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW1_CH1, val);
        }

        mutex_unlock(&dev_priv->sb_lock);

        /*
         * Leave the power down bit cleared for at least one
         * lane so that chv_powergate_phy_ch() will power
         * on something when the channel is otherwise unused.
         * When the port is off and the override is removed
         * the lanes power down anyway, so otherwise it doesn't
         * really matter what the state of power down bits is
         * after this.
         */
        chv_phy_powergate_lanes(encoder, false, 0x0);
}

/*
 * Native read with retry for link status and receiver capability reads for
 * cases where the sink may still be asleep.
 *
 * Sinks are *supposed* to come up within 1ms from an off state, but we're also
 * supposed to retry 3 times per the spec.
 */
static ssize_t
intel_dp_dpcd_read_wake(struct drm_dp_aux *aux, unsigned int offset,
                        void *buffer, size_t size)
{
        ssize_t ret;
        int i;

        /*
         * Sometime we just get the same incorrect byte repeated
         * over the entire buffer. Doing just one throw away read
         * initially seems to "solve" it.
         */
        drm_dp_dpcd_read(aux, DP_DPCD_REV, buffer, 1);

        for (i = 0; i < 3; i++) {
                ret = drm_dp_dpcd_read(aux, offset, buffer, size);
                if (ret == size)
                        return ret;
                msleep(1);
        }

        return ret;
}

/*
 * Fetch AUX CH registers 0x202 - 0x207 which contain
 * link status information
 */
static bool
intel_dp_get_link_status(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_STATUS_SIZE])
{
        return intel_dp_dpcd_read_wake(&intel_dp->aux,
                                       DP_LANE0_1_STATUS,
                                       link_status,
                                       DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
}

/* These are source-specific values. */
static uint8_t
intel_dp_voltage_max(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = dp_to_dig_port(intel_dp)->port;

        if (IS_BROXTON(dev))
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
        else if (INTEL_INFO(dev)->gen >= 9) {
                if (dev_priv->edp_low_vswing && port == PORT_A)
                        return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
        } else if (IS_VALLEYVIEW(dev))
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
        else if (IS_GEN7(dev) && port == PORT_A)
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
        else if (HAS_PCH_CPT(dev) && port != PORT_A)
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
        else
                return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
}

static uint8_t
intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        enum port port = dp_to_dig_port(intel_dp)->port;

        if (INTEL_INFO(dev)->gen >= 9) {
                switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        return DP_TRAIN_PRE_EMPH_LEVEL_3;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        return DP_TRAIN_PRE_EMPH_LEVEL_1;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                default:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                }
        } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
                switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        return DP_TRAIN_PRE_EMPH_LEVEL_3;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        return DP_TRAIN_PRE_EMPH_LEVEL_1;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                default:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                }
        } else if (IS_VALLEYVIEW(dev)) {
                switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        return DP_TRAIN_PRE_EMPH_LEVEL_3;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        return DP_TRAIN_PRE_EMPH_LEVEL_1;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                default:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                }
        } else if (IS_GEN7(dev) && port == PORT_A) {
                switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        return DP_TRAIN_PRE_EMPH_LEVEL_1;
                default:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                }
        } else {
                switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        return DP_TRAIN_PRE_EMPH_LEVEL_2;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        return DP_TRAIN_PRE_EMPH_LEVEL_1;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                default:
                        return DP_TRAIN_PRE_EMPH_LEVEL_0;
                }
        }
}

static uint32_t vlv_signal_levels(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
        struct intel_crtc *intel_crtc =
                to_intel_crtc(dport->base.base.crtc);
        unsigned long demph_reg_value, preemph_reg_value,
                uniqtranscale_reg_value;
        uint8_t train_set = intel_dp->train_set[0];
        enum dpio_channel port = vlv_dport_to_channel(dport);
        int pipe = intel_crtc->pipe;

        switch (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) {
        case DP_TRAIN_PRE_EMPH_LEVEL_0:
                preemph_reg_value = 0x0004000;
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        demph_reg_value = 0x2B405555;
                        uniqtranscale_reg_value = 0x552AB83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        demph_reg_value = 0x2B404040;
                        uniqtranscale_reg_value = 0x5548B83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        demph_reg_value = 0x2B245555;
                        uniqtranscale_reg_value = 0x5560B83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                        demph_reg_value = 0x2B405555;
                        uniqtranscale_reg_value = 0x5598DA3A;
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_1:
                preemph_reg_value = 0x0002000;
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        demph_reg_value = 0x2B404040;
                        uniqtranscale_reg_value = 0x5552B83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        demph_reg_value = 0x2B404848;
                        uniqtranscale_reg_value = 0x5580B83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        demph_reg_value = 0x2B404040;
                        uniqtranscale_reg_value = 0x55ADDA3A;
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_2:
                preemph_reg_value = 0x0000000;
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        demph_reg_value = 0x2B305555;
                        uniqtranscale_reg_value = 0x5570B83A;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        demph_reg_value = 0x2B2B4040;
                        uniqtranscale_reg_value = 0x55ADDA3A;
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_3:
                preemph_reg_value = 0x0006000;
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        demph_reg_value = 0x1B405555;
                        uniqtranscale_reg_value = 0x55ADDA3A;
                        break;
                default:
                        return 0;
                }
                break;
        default:
                return 0;
        }

        mutex_lock(&dev_priv->sb_lock);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW5(port), 0x00000000);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW4(port), demph_reg_value);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW2(port),
                         uniqtranscale_reg_value);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW3(port), 0x0C782040);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW11(port), 0x00030000);
        vlv_dpio_write(dev_priv, pipe, VLV_PCS_DW9(port), preemph_reg_value);
        vlv_dpio_write(dev_priv, pipe, VLV_TX_DW5(port), 0x80000000);
        mutex_unlock(&dev_priv->sb_lock);

        return 0;
}

static bool chv_need_uniq_trans_scale(uint8_t train_set)
{
        return (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) == DP_TRAIN_PRE_EMPH_LEVEL_0 &&
                (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) == DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
}

static uint32_t chv_signal_levels(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *dport = dp_to_dig_port(intel_dp);
        struct intel_crtc *intel_crtc = to_intel_crtc(dport->base.base.crtc);
        u32 deemph_reg_value, margin_reg_value, val;
        uint8_t train_set = intel_dp->train_set[0];
        enum dpio_channel ch = vlv_dport_to_channel(dport);
        enum pipe pipe = intel_crtc->pipe;
        int i;

        switch (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) {
        case DP_TRAIN_PRE_EMPH_LEVEL_0:
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        deemph_reg_value = 128;
                        margin_reg_value = 52;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        deemph_reg_value = 128;
                        margin_reg_value = 77;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        deemph_reg_value = 128;
                        margin_reg_value = 102;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                        deemph_reg_value = 128;
                        margin_reg_value = 154;
                        /* FIXME extra to set for 1200 */
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_1:
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        deemph_reg_value = 85;
                        margin_reg_value = 78;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        deemph_reg_value = 85;
                        margin_reg_value = 116;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                        deemph_reg_value = 85;
                        margin_reg_value = 154;
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_2:
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        deemph_reg_value = 64;
                        margin_reg_value = 104;
                        break;
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                        deemph_reg_value = 64;
                        margin_reg_value = 154;
                        break;
                default:
                        return 0;
                }
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_3:
                switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
                case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
                        deemph_reg_value = 43;
                        margin_reg_value = 154;
                        break;
                default:
                        return 0;
                }
                break;
        default:
                return 0;
        }

        mutex_lock(&dev_priv->sb_lock);

        /* Clear calc init */
        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));
        val &= ~(DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3);
        val &= ~(DPIO_PCS_TX1DEEMP_MASK | DPIO_PCS_TX2DEEMP_MASK);
        val |= DPIO_PCS_TX1DEEMP_9P5 | DPIO_PCS_TX2DEEMP_9P5;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW10(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW10(ch));
                val &= ~(DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3);
                val &= ~(DPIO_PCS_TX1DEEMP_MASK | DPIO_PCS_TX2DEEMP_MASK);
                val |= DPIO_PCS_TX1DEEMP_9P5 | DPIO_PCS_TX2DEEMP_9P5;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
        }

        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW9(ch));
        val &= ~(DPIO_PCS_TX1MARGIN_MASK | DPIO_PCS_TX2MARGIN_MASK);
        val |= DPIO_PCS_TX1MARGIN_000 | DPIO_PCS_TX2MARGIN_000;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW9(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW9(ch));
                val &= ~(DPIO_PCS_TX1MARGIN_MASK | DPIO_PCS_TX2MARGIN_MASK);
                val |= DPIO_PCS_TX1MARGIN_000 | DPIO_PCS_TX2MARGIN_000;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW9(ch), val);
        }

        /* Program swing deemph */
        for (i = 0; i < intel_crtc->config->lane_count; i++) {
                val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW4(ch, i));
                val &= ~DPIO_SWING_DEEMPH9P5_MASK;
                val |= deemph_reg_value << DPIO_SWING_DEEMPH9P5_SHIFT;
                vlv_dpio_write(dev_priv, pipe, CHV_TX_DW4(ch, i), val);
        }

        /* Program swing margin */
        for (i = 0; i < intel_crtc->config->lane_count; i++) {
                val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW2(ch, i));

                val &= ~DPIO_SWING_MARGIN000_MASK;
                val |= margin_reg_value << DPIO_SWING_MARGIN000_SHIFT;

                /*
                 * Supposedly this value shouldn't matter when unique transition
                 * scale is disabled, but in fact it does matter. Let's just
                 * always program the same value and hope it's OK.
                 */
                val &= ~(0xff << DPIO_UNIQ_TRANS_SCALE_SHIFT);
                val |= 0x9a << DPIO_UNIQ_TRANS_SCALE_SHIFT;

                vlv_dpio_write(dev_priv, pipe, CHV_TX_DW2(ch, i), val);
        }

        /*
         * The document said it needs to set bit 27 for ch0 and bit 26
         * for ch1. Might be a typo in the doc.
         * For now, for this unique transition scale selection, set bit
         * 27 for ch0 and ch1.
         */
        for (i = 0; i < intel_crtc->config->lane_count; i++) {
                val = vlv_dpio_read(dev_priv, pipe, CHV_TX_DW3(ch, i));
                if (chv_need_uniq_trans_scale(train_set))
                        val |= DPIO_TX_UNIQ_TRANS_SCALE_EN;
                else
                        val &= ~DPIO_TX_UNIQ_TRANS_SCALE_EN;
                vlv_dpio_write(dev_priv, pipe, CHV_TX_DW3(ch, i), val);
        }

        /* Start swing calculation */
        val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));
        val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3;
        vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW10(ch), val);

        if (intel_crtc->config->lane_count > 2) {
                val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW10(ch));
                val |= DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3;
                vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW10(ch), val);
        }

        mutex_unlock(&dev_priv->sb_lock);

        return 0;
}

static void
intel_get_adjust_train(struct intel_dp *intel_dp,
                       const uint8_t link_status[DP_LINK_STATUS_SIZE])
{
        uint8_t v = 0;
        uint8_t p = 0;
        int lane;
        uint8_t voltage_max;
        uint8_t preemph_max;

        for (lane = 0; lane < intel_dp->lane_count; lane++) {
                uint8_t this_v = drm_dp_get_adjust_request_voltage(link_status, lane);
                uint8_t this_p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);

                if (this_v > v)
                        v = this_v;
                if (this_p > p)
                        p = this_p;
        }

        voltage_max = intel_dp_voltage_max(intel_dp);
        if (v >= voltage_max)
                v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;

        preemph_max = intel_dp_pre_emphasis_max(intel_dp, v);
        if (p >= preemph_max)
                p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;

        for (lane = 0; lane < 4; lane++)
                intel_dp->train_set[lane] = v | p;
}

static uint32_t
gen4_signal_levels(uint8_t train_set)
{
        uint32_t        signal_levels = 0;

        switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
        default:
                signal_levels |= DP_VOLTAGE_0_4;
                break;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
                signal_levels |= DP_VOLTAGE_0_6;
                break;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
                signal_levels |= DP_VOLTAGE_0_8;
                break;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
                signal_levels |= DP_VOLTAGE_1_2;
                break;
        }
        switch (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) {
        case DP_TRAIN_PRE_EMPH_LEVEL_0:
        default:
                signal_levels |= DP_PRE_EMPHASIS_0;
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_1:
                signal_levels |= DP_PRE_EMPHASIS_3_5;
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_2:
                signal_levels |= DP_PRE_EMPHASIS_6;
                break;
        case DP_TRAIN_PRE_EMPH_LEVEL_3:
                signal_levels |= DP_PRE_EMPHASIS_9_5;
                break;
        }
        return signal_levels;
}

/* Gen6's DP voltage swing and pre-emphasis control */
static uint32_t
gen6_edp_signal_levels(uint8_t train_set)
{
        int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
                                         DP_TRAIN_PRE_EMPHASIS_MASK);
        switch (signal_levels) {
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_0:
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_0:
                return EDP_LINK_TRAIN_400_600MV_0DB_SNB_B;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_1:
                return EDP_LINK_TRAIN_400MV_3_5DB_SNB_B;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_2:
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_2:
                return EDP_LINK_TRAIN_400_600MV_6DB_SNB_B;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_1:
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_1:
                return EDP_LINK_TRAIN_600_800MV_3_5DB_SNB_B;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_0:
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_3 | DP_TRAIN_PRE_EMPH_LEVEL_0:
                return EDP_LINK_TRAIN_800_1200MV_0DB_SNB_B;
        default:
                DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level:"
                              "0x%x\n", signal_levels);
                return EDP_LINK_TRAIN_400_600MV_0DB_SNB_B;
        }
}

/* Gen7's DP voltage swing and pre-emphasis control */
static uint32_t
gen7_edp_signal_levels(uint8_t train_set)
{
        int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
                                         DP_TRAIN_PRE_EMPHASIS_MASK);
        switch (signal_levels) {
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_0:
                return EDP_LINK_TRAIN_400MV_0DB_IVB;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_1:
                return EDP_LINK_TRAIN_400MV_3_5DB_IVB;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | DP_TRAIN_PRE_EMPH_LEVEL_2:
                return EDP_LINK_TRAIN_400MV_6DB_IVB;

        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_0:
                return EDP_LINK_TRAIN_600MV_0DB_IVB;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_1 | DP_TRAIN_PRE_EMPH_LEVEL_1:
                return EDP_LINK_TRAIN_600MV_3_5DB_IVB;

        case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_0:
                return EDP_LINK_TRAIN_800MV_0DB_IVB;
        case DP_TRAIN_VOLTAGE_SWING_LEVEL_2 | DP_TRAIN_PRE_EMPH_LEVEL_1:
                return EDP_LINK_TRAIN_800MV_3_5DB_IVB;

        default:
                DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level:"
                              "0x%x\n", signal_levels);
                return EDP_LINK_TRAIN_500MV_0DB_IVB;
        }
}

/* Properly updates "DP" with the correct signal levels. */
static void
intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        enum port port = intel_dig_port->port;
        struct drm_device *dev = intel_dig_port->base.base.dev;
        uint32_t signal_levels, mask = 0;
        uint8_t train_set = intel_dp->train_set[0];

        if (HAS_DDI(dev)) {
                signal_levels = ddi_signal_levels(intel_dp);

                if (IS_BROXTON(dev))
                        signal_levels = 0;
                else
                        mask = DDI_BUF_EMP_MASK;
        } else if (IS_CHERRYVIEW(dev)) {
                signal_levels = chv_signal_levels(intel_dp);
        } else if (IS_VALLEYVIEW(dev)) {
                signal_levels = vlv_signal_levels(intel_dp);
        } else if (IS_GEN7(dev) && port == PORT_A) {
                signal_levels = gen7_edp_signal_levels(train_set);
                mask = EDP_LINK_TRAIN_VOL_EMP_MASK_IVB;
        } else if (IS_GEN6(dev) && port == PORT_A) {
                signal_levels = gen6_edp_signal_levels(train_set);
                mask = EDP_LINK_TRAIN_VOL_EMP_MASK_SNB;
        } else {
                signal_levels = gen4_signal_levels(train_set);
                mask = DP_VOLTAGE_MASK | DP_PRE_EMPHASIS_MASK;
        }

        if (mask)
                DRM_DEBUG_KMS("Using signal levels %08x\n", signal_levels);

        DRM_DEBUG_KMS("Using vswing level %d\n",
                train_set & DP_TRAIN_VOLTAGE_SWING_MASK);
        DRM_DEBUG_KMS("Using pre-emphasis level %d\n",
                (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) >>
                        DP_TRAIN_PRE_EMPHASIS_SHIFT);

        *DP = (*DP & ~mask) | signal_levels;
}

static bool
intel_dp_set_link_train(struct intel_dp *intel_dp,
                        uint32_t *DP,
                        uint8_t dp_train_pat)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv =
                to_i915(intel_dig_port->base.base.dev);
        uint8_t buf[sizeof(intel_dp->train_set) + 1];
        int ret, len;

        _intel_dp_set_link_train(intel_dp, DP, dp_train_pat);

        I915_WRITE(intel_dp->output_reg, *DP);
        POSTING_READ(intel_dp->output_reg);

        buf[0] = dp_train_pat;
        if ((dp_train_pat & DP_TRAINING_PATTERN_MASK) ==
            DP_TRAINING_PATTERN_DISABLE) {
                /* don't write DP_TRAINING_LANEx_SET on disable */
                len = 1;
        } else {
                /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */
                memcpy(buf + 1, intel_dp->train_set, intel_dp->lane_count);
                len = intel_dp->lane_count + 1;
        }

        ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_PATTERN_SET,
                                buf, len);

        return ret == len;
}

static bool
intel_dp_reset_link_train(struct intel_dp *intel_dp, uint32_t *DP,
                        uint8_t dp_train_pat)
{
        if (!intel_dp->train_set_valid)
                memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set));
        intel_dp_set_signal_levels(intel_dp, DP);
        return intel_dp_set_link_train(intel_dp, DP, dp_train_pat);
}

static bool
intel_dp_update_link_train(struct intel_dp *intel_dp, uint32_t *DP,
                           const uint8_t link_status[DP_LINK_STATUS_SIZE])
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_i915_private *dev_priv =
                to_i915(intel_dig_port->base.base.dev);
        int ret;

        intel_get_adjust_train(intel_dp, link_status);
        intel_dp_set_signal_levels(intel_dp, DP);

        I915_WRITE(intel_dp->output_reg, *DP);
        POSTING_READ(intel_dp->output_reg);

        ret = drm_dp_dpcd_write(&intel_dp->aux, DP_TRAINING_LANE0_SET,
                                intel_dp->train_set, intel_dp->lane_count);

        return ret == intel_dp->lane_count;
}

static void intel_dp_set_idle_link_train(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = intel_dig_port->port;
        uint32_t val;

        if (!HAS_DDI(dev))
                return;

        val = I915_READ(DP_TP_CTL(port));
        val &= ~DP_TP_CTL_LINK_TRAIN_MASK;
        val |= DP_TP_CTL_LINK_TRAIN_IDLE;
        I915_WRITE(DP_TP_CTL(port), val);

        /*
         * On PORT_A we can have only eDP in SST mode. There the only reason
         * we need to set idle transmission mode is to work around a HW issue
         * where we enable the pipe while not in idle link-training mode.
         * In this case there is requirement to wait for a minimum number of
         * idle patterns to be sent.
         */
        if (port == PORT_A)
                return;

        if (wait_for((I915_READ(DP_TP_STATUS(port)) & DP_TP_STATUS_IDLE_DONE),
                     1))
                DRM_ERROR("Timed out waiting for DP idle patterns\n");
}

/* Enable corresponding port and start training pattern 1 */
static void
intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp)
{
        struct drm_encoder *encoder = &dp_to_dig_port(intel_dp)->base.base;
        struct drm_device *dev = encoder->dev;
        int i;
        uint8_t voltage;
        int voltage_tries, loop_tries;
        uint32_t DP = intel_dp->DP;
        uint8_t link_config[2];
        uint8_t link_bw, rate_select;

        if (HAS_DDI(dev))
                intel_ddi_prepare_link_retrain(encoder);

        intel_dp_compute_rate(intel_dp, intel_dp->link_rate,
                              &link_bw, &rate_select);

        /* Write the link configuration data */
        link_config[0] = link_bw;
        link_config[1] = intel_dp->lane_count;
        if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
                link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
        drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2);
        if (intel_dp->num_sink_rates)
                drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET,
                                  &rate_select, 1);

        link_config[0] = 0;
        link_config[1] = DP_SET_ANSI_8B10B;
        drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);

        DP |= DP_PORT_EN;

        /* clock recovery */
        if (!intel_dp_reset_link_train(intel_dp, &DP,
                                       DP_TRAINING_PATTERN_1 |
                                       DP_LINK_SCRAMBLING_DISABLE)) {
                DRM_ERROR("failed to enable link training\n");
                return;
        }

        voltage = 0xff;
        voltage_tries = 0;
        loop_tries = 0;
        for (;;) {
                uint8_t link_status[DP_LINK_STATUS_SIZE];

                drm_dp_link_train_clock_recovery_delay(intel_dp->dpcd);
                if (!intel_dp_get_link_status(intel_dp, link_status)) {
                        DRM_ERROR("failed to get link status\n");
                        break;
                }

                if (drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) {
                        DRM_DEBUG_KMS("clock recovery OK\n");
                        break;
                }

                /*
                 * if we used previously trained voltage and pre-emphasis values
                 * and we don't get clock recovery, reset link training values
                 */
                if (intel_dp->train_set_valid) {
                        DRM_DEBUG_KMS("clock recovery not ok, reset");
                        /* clear the flag as we are not reusing train set */
                        intel_dp->train_set_valid = false;
                        if (!intel_dp_reset_link_train(intel_dp, &DP,
                                                       DP_TRAINING_PATTERN_1 |
                                                       DP_LINK_SCRAMBLING_DISABLE)) {
                                DRM_ERROR("failed to enable link training\n");
                                return;
                        }
                        continue;
                }

                /* Check to see if we've tried the max voltage */
                for (i = 0; i < intel_dp->lane_count; i++)
                        if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
                                break;
                if (i == intel_dp->lane_count) {
                        ++loop_tries;
                        if (loop_tries == 5) {
                                DRM_ERROR("too many full retries, give up\n");
                                break;
                        }
                        intel_dp_reset_link_train(intel_dp, &DP,
                                                  DP_TRAINING_PATTERN_1 |
                                                  DP_LINK_SCRAMBLING_DISABLE);
                        voltage_tries = 0;
                        continue;
                }

                /* Check to see if we've tried the same voltage 5 times */
                if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
                        ++voltage_tries;
                        if (voltage_tries == 5) {
                                DRM_ERROR("too many voltage retries, give up\n");
                                break;
                        }
                } else
                        voltage_tries = 0;
                voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;

                /* Update training set as requested by target */
                if (!intel_dp_update_link_train(intel_dp, &DP, link_status)) {
                        DRM_ERROR("failed to update link training\n");
                        break;
                }
        }

        intel_dp->DP = DP;
}

static void
intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = dig_port->base.base.dev;
        bool channel_eq = false;
        int tries, cr_tries;
        uint32_t DP = intel_dp->DP;
        uint32_t training_pattern = DP_TRAINING_PATTERN_2;

        /*
         * Training Pattern 3 for HBR2 or 1.2 devices that support it.
         *
         * Intel platforms that support HBR2 also support TPS3. TPS3 support is
         * also mandatory for downstream devices that support HBR2.
         *
         * Due to WaDisableHBR2 SKL < B0 is the only exception where TPS3 is
         * supported but still not enabled.
         */
        if (intel_dp_source_supports_hbr2(dev) &&
            drm_dp_tps3_supported(intel_dp->dpcd))
                training_pattern = DP_TRAINING_PATTERN_3;
        else if (intel_dp->link_rate == 540000)
                DRM_ERROR("5.4 Gbps link rate without HBR2/TPS3 support\n");

        /* channel equalization */
        if (!intel_dp_set_link_train(intel_dp, &DP,
                                     training_pattern |
                                     DP_LINK_SCRAMBLING_DISABLE)) {
                DRM_ERROR("failed to start channel equalization\n");
                return;
        }

        tries = 0;
        cr_tries = 0;
        channel_eq = false;
        for (;;) {
                uint8_t link_status[DP_LINK_STATUS_SIZE];

                if (cr_tries > 5) {
                        DRM_ERROR("failed to train DP, aborting\n");
                        break;
                }

                drm_dp_link_train_channel_eq_delay(intel_dp->dpcd);
                if (!intel_dp_get_link_status(intel_dp, link_status)) {
                        DRM_ERROR("failed to get link status\n");
                        break;
                }

                /* Make sure clock is still ok */
                if (!drm_dp_clock_recovery_ok(link_status,
                                              intel_dp->lane_count)) {
                        intel_dp->train_set_valid = false;
                        intel_dp_link_training_clock_recovery(intel_dp);
                        intel_dp_set_link_train(intel_dp, &DP,
                                                training_pattern |
                                                DP_LINK_SCRAMBLING_DISABLE);
                        cr_tries++;
                        continue;
                }

                if (drm_dp_channel_eq_ok(link_status,
                                         intel_dp->lane_count)) {
                        channel_eq = true;
                        break;
                }

                /* Try 5 times, then try clock recovery if that fails */
                if (tries > 5) {
                        intel_dp->train_set_valid = false;
                        intel_dp_link_training_clock_recovery(intel_dp);
                        intel_dp_set_link_train(intel_dp, &DP,
                                                training_pattern |
                                                DP_LINK_SCRAMBLING_DISABLE);
                        tries = 0;
                        cr_tries++;
                        continue;
                }

                /* Update training set as requested by target */
                if (!intel_dp_update_link_train(intel_dp, &DP, link_status)) {
                        DRM_ERROR("failed to update link training\n");
                        break;
                }
                ++tries;
        }

        intel_dp_set_idle_link_train(intel_dp);

        intel_dp->DP = DP;

        if (channel_eq) {
                intel_dp->train_set_valid = true;
                DRM_DEBUG_KMS("Channel EQ done. DP Training successful\n");
        }
}

void intel_dp_stop_link_train(struct intel_dp *intel_dp)
{
        intel_dp_set_link_train(intel_dp, &intel_dp->DP,
                                DP_TRAINING_PATTERN_DISABLE);
}

void
intel_dp_start_link_train(struct intel_dp *intel_dp)
{
        intel_dp_link_training_clock_recovery(intel_dp);
        intel_dp_link_training_channel_equalization(intel_dp);
}

static void
intel_dp_link_down(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_crtc *crtc = to_intel_crtc(intel_dig_port->base.base.crtc);
        enum port port = intel_dig_port->port;
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t DP = intel_dp->DP;

        if (WARN_ON(HAS_DDI(dev)))
                return;

        if (WARN_ON((I915_READ(intel_dp->output_reg) & DP_PORT_EN) == 0))
                return;

        DRM_DEBUG_KMS("\n");

        if ((IS_GEN7(dev) && port == PORT_A) ||
            (HAS_PCH_CPT(dev) && port != PORT_A)) {
                DP &= ~DP_LINK_TRAIN_MASK_CPT;
                DP |= DP_LINK_TRAIN_PAT_IDLE_CPT;
        } else {
                if (IS_CHERRYVIEW(dev))
                        DP &= ~DP_LINK_TRAIN_MASK_CHV;
                else
                        DP &= ~DP_LINK_TRAIN_MASK;
                DP |= DP_LINK_TRAIN_PAT_IDLE;
        }
        I915_WRITE(intel_dp->output_reg, DP);
        POSTING_READ(intel_dp->output_reg);

        DP &= ~(DP_PORT_EN | DP_AUDIO_OUTPUT_ENABLE);
        I915_WRITE(intel_dp->output_reg, DP);
        POSTING_READ(intel_dp->output_reg);

        /*
         * HW workaround for IBX, we need to move the port
         * to transcoder A after disabling it to allow the
         * matching HDMI port to be enabled on transcoder A.
         */
        if (HAS_PCH_IBX(dev) && crtc->pipe == PIPE_B && port != PORT_A) {
                /* always enable with pattern 1 (as per spec) */
                DP &= ~(DP_PIPEB_SELECT | DP_LINK_TRAIN_MASK);
                DP |= DP_PORT_EN | DP_LINK_TRAIN_PAT_1;
                I915_WRITE(intel_dp->output_reg, DP);
                POSTING_READ(intel_dp->output_reg);

                DP &= ~DP_PORT_EN;
                I915_WRITE(intel_dp->output_reg, DP);
                POSTING_READ(intel_dp->output_reg);
        }

        msleep(intel_dp->panel_power_down_delay);
}

static bool
intel_dp_get_dpcd(struct intel_dp *intel_dp)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint8_t rev;

        if (intel_dp_dpcd_read_wake(&intel_dp->aux, 0x000, intel_dp->dpcd,
                                    sizeof(intel_dp->dpcd)) < 0)
                return false; /* aux transfer failed */

        DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd);

        if (intel_dp->dpcd[DP_DPCD_REV] == 0)
                return false; /* DPCD not present */

        /* Check if the panel supports PSR */
        memset(intel_dp->psr_dpcd, 0, sizeof(intel_dp->psr_dpcd));
        if (is_edp(intel_dp)) {
                intel_dp_dpcd_read_wake(&intel_dp->aux, DP_PSR_SUPPORT,
                                        intel_dp->psr_dpcd,
                                        sizeof(intel_dp->psr_dpcd));
                if (intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED) {
                        dev_priv->psr.sink_support = true;
                        DRM_DEBUG_KMS("Detected EDP PSR Panel.\n");
                }

                if (INTEL_INFO(dev)->gen >= 9 &&
                        (intel_dp->psr_dpcd[0] & DP_PSR2_IS_SUPPORTED)) {
                        uint8_t frame_sync_cap;

                        dev_priv->psr.sink_support = true;
                        intel_dp_dpcd_read_wake(&intel_dp->aux,
                                        DP_SINK_DEVICE_AUX_FRAME_SYNC_CAP,
                                        &frame_sync_cap, 1);
                        dev_priv->psr.aux_frame_sync = frame_sync_cap ? true : false;
                        /* PSR2 needs frame sync as well */
                        dev_priv->psr.psr2_support = dev_priv->psr.aux_frame_sync;
                        DRM_DEBUG_KMS("PSR2 %s on sink",
                                dev_priv->psr.psr2_support ? "supported" : "not supported");
                }
        }

        DRM_DEBUG_KMS("Display Port TPS3 support: source %s, sink %s\n",
                      yesno(intel_dp_source_supports_hbr2(dev)),
                      yesno(drm_dp_tps3_supported(intel_dp->dpcd)));

        /* Intermediate frequency support */
        if (is_edp(intel_dp) &&
            (intel_dp->dpcd[DP_EDP_CONFIGURATION_CAP] & DP_DPCD_DISPLAY_CONTROL_CAPABLE) &&
            (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_EDP_DPCD_REV, &rev, 1) == 1) &&
            (rev >= 0x03)) { /* eDp v1.4 or higher */
                __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
                int i;

                intel_dp_dpcd_read_wake(&intel_dp->aux,
                                DP_SUPPORTED_LINK_RATES,
                                sink_rates,
                                sizeof(sink_rates));

                for (i = 0; i < ARRAY_SIZE(sink_rates); i++) {
                        int val = le16_to_cpu(sink_rates[i]);

                        if (val == 0)
                                break;

                        /* Value read is in kHz while drm clock is saved in deca-kHz */
                        intel_dp->sink_rates[i] = (val * 200) / 10;
                }
                intel_dp->num_sink_rates = i;
        }

        intel_dp_print_rates(intel_dp);

        if (!(intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
              DP_DWN_STRM_PORT_PRESENT))
                return true; /* native DP sink */

        if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
                return true; /* no per-port downstream info */

        if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
                                    intel_dp->downstream_ports,
                                    DP_MAX_DOWNSTREAM_PORTS) < 0)
                return false; /* downstream port status fetch failed */

        return true;
}

static void
intel_dp_probe_oui(struct intel_dp *intel_dp)
{
        u8 buf[3];

        if (!(intel_dp->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
                return;

        if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_OUI, buf, 3) == 3)
                DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
                              buf[0], buf[1], buf[2]);

        if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_BRANCH_OUI, buf, 3) == 3)
                DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
                              buf[0], buf[1], buf[2]);
}

static bool
intel_dp_probe_mst(struct intel_dp *intel_dp)
{
        u8 buf[1];

        if (!intel_dp->can_mst)
                return false;

        if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
                return false;

        if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_MSTM_CAP, buf, 1)) {
                if (buf[0] & DP_MST_CAP) {
                        DRM_DEBUG_KMS("Sink is MST capable\n");
                        intel_dp->is_mst = true;
                } else {
                        DRM_DEBUG_KMS("Sink is not MST capable\n");
                        intel_dp->is_mst = false;
                }
        }

        drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
        return intel_dp->is_mst;
}

static int intel_dp_sink_crc_stop(struct intel_dp *intel_dp)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct intel_crtc *intel_crtc = to_intel_crtc(dig_port->base.base.crtc);
        u8 buf;
        int ret = 0;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0) {
                DRM_DEBUG_KMS("Sink CRC couldn't be stopped properly\n");
                ret = -EIO;
                goto out;
        }

        if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
                               buf & ~DP_TEST_SINK_START) < 0) {
                DRM_DEBUG_KMS("Sink CRC couldn't be stopped properly\n");
                ret = -EIO;
                goto out;
        }

        intel_dp->sink_crc.started = false;
 out:
        hsw_enable_ips(intel_crtc);
        return ret;
}

static int intel_dp_sink_crc_start(struct intel_dp *intel_dp)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct intel_crtc *intel_crtc = to_intel_crtc(dig_port->base.base.crtc);
        u8 buf;
        int ret;

        if (intel_dp->sink_crc.started) {
                ret = intel_dp_sink_crc_stop(intel_dp);
                if (ret)
                        return ret;
        }

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf) < 0)
                return -EIO;

        if (!(buf & DP_TEST_CRC_SUPPORTED))
                return -ENOTTY;

        intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;

        if (drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf) < 0)
                return -EIO;

        hsw_disable_ips(intel_crtc);

        if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK,
                               buf | DP_TEST_SINK_START) < 0) {
                hsw_enable_ips(intel_crtc);
                return -EIO;
        }

        intel_dp->sink_crc.started = true;
        return 0;
}

int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc)
{
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = dig_port->base.base.dev;
        struct intel_crtc *intel_crtc = to_intel_crtc(dig_port->base.base.crtc);
        u8 buf;
        int count, ret;
        int attempts = 6;
        bool old_equal_new;

        ret = intel_dp_sink_crc_start(intel_dp);
        if (ret)
                return ret;

        do {
                intel_wait_for_vblank(dev, intel_crtc->pipe);

                if (drm_dp_dpcd_readb(&intel_dp->aux,
                                      DP_TEST_SINK_MISC, &buf) < 0) {
                        ret = -EIO;
                        goto stop;
                }
                count = buf & DP_TEST_COUNT_MASK;

                /*
                 * Count might be reset during the loop. In this case
                 * last known count needs to be reset as well.
                 */
                if (count == 0)
                        intel_dp->sink_crc.last_count = 0;

                if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) {
                        ret = -EIO;
                        goto stop;
                }

                old_equal_new = (count == intel_dp->sink_crc.last_count &&
                                 !memcmp(intel_dp->sink_crc.last_crc, crc,
                                         6 * sizeof(u8)));

        } while (--attempts && (count == 0 || old_equal_new));

        intel_dp->sink_crc.last_count = buf & DP_TEST_COUNT_MASK;
        memcpy(intel_dp->sink_crc.last_crc, crc, 6 * sizeof(u8));

        if (attempts == 0) {
                if (old_equal_new) {
                        DRM_DEBUG_KMS("Unreliable Sink CRC counter: Current returned CRC is identical to the previous one\n");
                } else {
                        DRM_ERROR("Panel is unable to calculate any CRC after 6 vblanks\n");
                        ret = -ETIMEDOUT;
                        goto stop;
                }
        }

stop:
        intel_dp_sink_crc_stop(intel_dp);
        return ret;
}

static bool
intel_dp_get_sink_irq(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
        return intel_dp_dpcd_read_wake(&intel_dp->aux,
                                       DP_DEVICE_SERVICE_IRQ_VECTOR,
                                       sink_irq_vector, 1) == 1;
}

static bool
intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector)
{
        int ret;

        ret = intel_dp_dpcd_read_wake(&intel_dp->aux,
                                             DP_SINK_COUNT_ESI,
                                             sink_irq_vector, 14);
        if (ret != 14)
                return false;

        return true;
}

static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp)
{
        uint8_t test_result = DP_TEST_ACK;
        return test_result;
}

static uint8_t intel_dp_autotest_video_pattern(struct intel_dp *intel_dp)
{
        uint8_t test_result = DP_TEST_NAK;
        return test_result;
}

static uint8_t intel_dp_autotest_edid(struct intel_dp *intel_dp)
{
        uint8_t test_result = DP_TEST_NAK;
        struct intel_connector *intel_connector = intel_dp->attached_connector;
        struct drm_connector *connector = &intel_connector->base;

        if (intel_connector->detect_edid == NULL ||
            connector->edid_corrupt ||
            intel_dp->aux.i2c_defer_count > 6) {
                /* Check EDID read for NACKs, DEFERs and corruption
                 * (DP CTS 1.2 Core r1.1)
                 *    4.2.2.4 : Failed EDID read, I2C_NAK
                 *    4.2.2.5 : Failed EDID read, I2C_DEFER
                 *    4.2.2.6 : EDID corruption detected
                 * Use failsafe mode for all cases
                 */
                if (intel_dp->aux.i2c_nack_count > 0 ||
                        intel_dp->aux.i2c_defer_count > 0)
                        DRM_DEBUG_KMS("EDID read had %d NACKs, %d DEFERs\n",
                                      intel_dp->aux.i2c_nack_count,
                                      intel_dp->aux.i2c_defer_count);
                intel_dp->compliance_test_data = INTEL_DP_RESOLUTION_FAILSAFE;
        } else {
                struct edid *block = intel_connector->detect_edid;

                /* We have to write the checksum
                 * of the last block read
                 */
                block += intel_connector->detect_edid->extensions;

                if (!drm_dp_dpcd_write(&intel_dp->aux,
                                        DP_TEST_EDID_CHECKSUM,
                                        &block->checksum,
                                        1))
                        DRM_DEBUG_KMS("Failed to write EDID checksum\n");

                test_result = DP_TEST_ACK | DP_TEST_EDID_CHECKSUM_WRITE;
                intel_dp->compliance_test_data = INTEL_DP_RESOLUTION_STANDARD;
        }

        /* Set test active flag here so userspace doesn't interrupt things */
        intel_dp->compliance_test_active = 1;

        return test_result;
}

static uint8_t intel_dp_autotest_phy_pattern(struct intel_dp *intel_dp)
{
        uint8_t test_result = DP_TEST_NAK;
        return test_result;
}

static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
{
        uint8_t response = DP_TEST_NAK;
        uint8_t rxdata = 0;
        int status = 0;

        intel_dp->compliance_test_active = 0;
        intel_dp->compliance_test_type = 0;
        intel_dp->compliance_test_data = 0;

        intel_dp->aux.i2c_nack_count = 0;
        intel_dp->aux.i2c_defer_count = 0;

        status = drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_REQUEST, &rxdata, 1);
        if (status <= 0) {
                DRM_DEBUG_KMS("Could not read test request from sink\n");
                goto update_status;
        }

        switch (rxdata) {
        case DP_TEST_LINK_TRAINING:
                DRM_DEBUG_KMS("LINK_TRAINING test requested\n");
                intel_dp->compliance_test_type = DP_TEST_LINK_TRAINING;
                response = intel_dp_autotest_link_training(intel_dp);
                break;
        case DP_TEST_LINK_VIDEO_PATTERN:
                DRM_DEBUG_KMS("TEST_PATTERN test requested\n");
                intel_dp->compliance_test_type = DP_TEST_LINK_VIDEO_PATTERN;
                response = intel_dp_autotest_video_pattern(intel_dp);
                break;
        case DP_TEST_LINK_EDID_READ:
                DRM_DEBUG_KMS("EDID test requested\n");
                intel_dp->compliance_test_type = DP_TEST_LINK_EDID_READ;
                response = intel_dp_autotest_edid(intel_dp);
                break;
        case DP_TEST_LINK_PHY_TEST_PATTERN:
                DRM_DEBUG_KMS("PHY_PATTERN test requested\n");
                intel_dp->compliance_test_type = DP_TEST_LINK_PHY_TEST_PATTERN;
                response = intel_dp_autotest_phy_pattern(intel_dp);
                break;
        default:
                DRM_DEBUG_KMS("Invalid test request '%02x'\n", rxdata);
                break;
        }

update_status:
        status = drm_dp_dpcd_write(&intel_dp->aux,
                                   DP_TEST_RESPONSE,
                                   &response, 1);
        if (status <= 0)
                DRM_DEBUG_KMS("Could not write test response to sink\n");
}

static int
intel_dp_check_mst_status(struct intel_dp *intel_dp)
{
        bool bret;

        if (intel_dp->is_mst) {
                u8 esi[16] = { 0 };
                int ret = 0;
                int retry;
                bool handled;
                bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
go_again:
                if (bret == true) {

                        /* check link status - esi[10] = 0x200c */
                        if (intel_dp->active_mst_links &&
                            !drm_dp_channel_eq_ok(&esi[10], intel_dp->lane_count)) {
                                DRM_DEBUG_KMS("channel EQ not ok, retraining\n");
                                intel_dp_start_link_train(intel_dp);
                                intel_dp_stop_link_train(intel_dp);
                        }

                        DRM_DEBUG_KMS("got esi %3ph\n", esi);
                        ret = drm_dp_mst_hpd_irq(&intel_dp->mst_mgr, esi, &handled);

                        if (handled) {
                                for (retry = 0; retry < 3; retry++) {
                                        int wret;
                                        wret = drm_dp_dpcd_write(&intel_dp->aux,
                                                                 DP_SINK_COUNT_ESI+1,
                                                                 &esi[1], 3);
                                        if (wret == 3) {
                                                break;
                                        }
                                }

                                bret = intel_dp_get_sink_irq_esi(intel_dp, esi);
                                if (bret == true) {
                                        DRM_DEBUG_KMS("got esi2 %3ph\n", esi);
                                        goto go_again;
                                }
                        } else
                                ret = 0;

                        return ret;
                } else {
                        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
                        DRM_DEBUG_KMS("failed to get ESI - device may have failed\n");
                        intel_dp->is_mst = false;
                        drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
                        /* send a hotplug event */
                        drm_kms_helper_hotplug_event(intel_dig_port->base.base.dev);
                }
        }
        return -EINVAL;
}

/*
 * According to DP spec
 * 5.1.2:
 *  1. Read DPCD
 *  2. Configure link according to Receiver Capabilities
 *  3. Use Link Training from 2.5.3.3 and 3.5.1.3
 *  4. Check link status on receipt of hot-plug interrupt
 */
static void
intel_dp_check_link_status(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base;
        u8 sink_irq_vector;
        u8 link_status[DP_LINK_STATUS_SIZE];

        WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));

        if (!intel_encoder->base.crtc)
                return;

        if (!to_intel_crtc(intel_encoder->base.crtc)->active)
                return;

        /* Try to read receiver status if the link appears to be up */
        if (!intel_dp_get_link_status(intel_dp, link_status)) {
                return;
        }

        /* Now read the DPCD to see if it's actually running */
        if (!intel_dp_get_dpcd(intel_dp)) {
                return;
        }

        /* Try to read the source of the interrupt */
        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
            intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
                /* Clear interrupt source */
                drm_dp_dpcd_writeb(&intel_dp->aux,
                                   DP_DEVICE_SERVICE_IRQ_VECTOR,
                                   sink_irq_vector);

                if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
                        DRM_DEBUG_DRIVER("Test request in short pulse not handled\n");
                if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
                        DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
        }

        if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) {
                DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n",
                              intel_encoder->base.name);
                intel_dp_start_link_train(intel_dp);
                intel_dp_stop_link_train(intel_dp);
        }
}

/* XXX this is probably wrong for multiple downstream ports */
static enum drm_connector_status
intel_dp_detect_dpcd(struct intel_dp *intel_dp)
{
        uint8_t *dpcd = intel_dp->dpcd;
        uint8_t type;

        if (!intel_dp_get_dpcd(intel_dp))
                return connector_status_disconnected;

        /* if there's no downstream port, we're done */
        if (!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
                return connector_status_connected;

        /* If we're HPD-aware, SINK_COUNT changes dynamically */
        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
            intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
                uint8_t reg;

                if (intel_dp_dpcd_read_wake(&intel_dp->aux, DP_SINK_COUNT,
                                            &reg, 1) < 0)
                        return connector_status_unknown;

                return DP_GET_SINK_COUNT(reg) ? connector_status_connected
                                              : connector_status_disconnected;
        }

        /* If no HPD, poke DDC gently */
        if (drm_probe_ddc(&intel_dp->aux.ddc))
                return connector_status_connected;

        /* Well we tried, say unknown for unreliable port types */
        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11) {
                type = intel_dp->downstream_ports[0] & DP_DS_PORT_TYPE_MASK;
                if (type == DP_DS_PORT_TYPE_VGA ||
                    type == DP_DS_PORT_TYPE_NON_EDID)
                        return connector_status_unknown;
        } else {
                type = intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
                        DP_DWN_STRM_PORT_TYPE_MASK;
                if (type == DP_DWN_STRM_PORT_TYPE_ANALOG ||
                    type == DP_DWN_STRM_PORT_TYPE_OTHER)
                        return connector_status_unknown;
        }

        /* Anything else is out of spec, warn and ignore */
        DRM_DEBUG_KMS("Broken DP branch device, ignoring\n");
        return connector_status_disconnected;
}

static enum drm_connector_status
edp_detect(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        enum drm_connector_status status;

        status = intel_panel_detect(dev);
        if (status == connector_status_unknown)
                status = connector_status_connected;

        return status;
}

static bool ibx_digital_port_connected(struct drm_i915_private *dev_priv,
                                       struct intel_digital_port *port)
{
        u32 bit;

        switch (port->port) {
        case PORT_A:
                return true;
        case PORT_B:
                bit = SDE_PORTB_HOTPLUG;
                break;
        case PORT_C:
                bit = SDE_PORTC_HOTPLUG;
                break;
        case PORT_D:
                bit = SDE_PORTD_HOTPLUG;
                break;
        default:
                MISSING_CASE(port->port);
                return false;
        }

        return I915_READ(SDEISR) & bit;
}

static bool cpt_digital_port_connected(struct drm_i915_private *dev_priv,
                                       struct intel_digital_port *port)
{
        u32 bit;

        switch (port->port) {
        case PORT_A:
                return true;
        case PORT_B:
                bit = SDE_PORTB_HOTPLUG_CPT;
                break;
        case PORT_C:
                bit = SDE_PORTC_HOTPLUG_CPT;
                break;
        case PORT_D:
                bit = SDE_PORTD_HOTPLUG_CPT;
                break;
        case PORT_E:
                bit = SDE_PORTE_HOTPLUG_SPT;
                break;
        default:
                MISSING_CASE(port->port);
                return false;
        }

        return I915_READ(SDEISR) & bit;
}

static bool g4x_digital_port_connected(struct drm_i915_private *dev_priv,
                                       struct intel_digital_port *port)
{
        u32 bit;

        switch (port->port) {
        case PORT_B:
                bit = PORTB_HOTPLUG_LIVE_STATUS_G4X;
                break;
        case PORT_C:
                bit = PORTC_HOTPLUG_LIVE_STATUS_G4X;
                break;
        case PORT_D:
                bit = PORTD_HOTPLUG_LIVE_STATUS_G4X;
                break;
        default:
                MISSING_CASE(port->port);
                return false;
        }

        return I915_READ(PORT_HOTPLUG_STAT) & bit;
}

static bool vlv_digital_port_connected(struct drm_i915_private *dev_priv,
                                       struct intel_digital_port *port)
{
        u32 bit;

        switch (port->port) {
        case PORT_B:
                bit = PORTB_HOTPLUG_LIVE_STATUS_VLV;
                break;
        case PORT_C:
                bit = PORTC_HOTPLUG_LIVE_STATUS_VLV;
                break;
        case PORT_D:
                bit = PORTD_HOTPLUG_LIVE_STATUS_VLV;
                break;
        default:
                MISSING_CASE(port->port);
                return false;
        }

        return I915_READ(PORT_HOTPLUG_STAT) & bit;
}

static bool bxt_digital_port_connected(struct drm_i915_private *dev_priv,
                                       struct intel_digital_port *intel_dig_port)
{
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        enum port port;
        u32 bit;

        intel_hpd_pin_to_port(intel_encoder->hpd_pin, &port);
        switch (port) {
        case PORT_A:
                bit = BXT_DE_PORT_HP_DDIA;
                break;
        case PORT_B:
                bit = BXT_DE_PORT_HP_DDIB;
                break;
        case PORT_C:
                bit = BXT_DE_PORT_HP_DDIC;
                break;
        default:
                MISSING_CASE(port);
                return false;
        }

        return I915_READ(GEN8_DE_PORT_ISR) & bit;
}

/*
 * intel_digital_port_connected - is the specified port connected?
 * @dev_priv: i915 private structure
 * @port: the port to test
 *
 * Return %true if @port is connected, %false otherwise.
 */
bool intel_digital_port_connected(struct drm_i915_private *dev_priv,
                                         struct intel_digital_port *port)
{
        if (HAS_PCH_IBX(dev_priv))
                return ibx_digital_port_connected(dev_priv, port);
        if (HAS_PCH_SPLIT(dev_priv))
                return cpt_digital_port_connected(dev_priv, port);
        else if (IS_BROXTON(dev_priv))
                return bxt_digital_port_connected(dev_priv, port);
        else if (IS_VALLEYVIEW(dev_priv))
                return vlv_digital_port_connected(dev_priv, port);
        else
                return g4x_digital_port_connected(dev_priv, port);
}

static enum drm_connector_status
ironlake_dp_detect(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);

        if (!intel_digital_port_connected(dev_priv, intel_dig_port))
                return connector_status_disconnected;

        return intel_dp_detect_dpcd(intel_dp);
}

static enum drm_connector_status
g4x_dp_detect(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);

        /* Can't disconnect eDP, but you can close the lid... */
        if (is_edp(intel_dp)) {
                enum drm_connector_status status;

                status = intel_panel_detect(dev);
                if (status == connector_status_unknown)
                        status = connector_status_connected;
                return status;
        }

        if (!intel_digital_port_connected(dev->dev_private, intel_dig_port))
                return connector_status_disconnected;

        return intel_dp_detect_dpcd(intel_dp);
}

static struct edid *
intel_dp_get_edid(struct intel_dp *intel_dp)
{
        struct intel_connector *intel_connector = intel_dp->attached_connector;

        /* use cached edid if we have one */
        if (intel_connector->edid) {
                /* invalid edid */
                if (IS_ERR(intel_connector->edid))
                        return NULL;

                return drm_edid_duplicate(intel_connector->edid);
        } else
                return drm_get_edid(&intel_connector->base,
                                    &intel_dp->aux.ddc);
}

static void
intel_dp_set_edid(struct intel_dp *intel_dp)
{
        struct intel_connector *intel_connector = intel_dp->attached_connector;
        struct edid *edid;

        edid = intel_dp_get_edid(intel_dp);
        intel_connector->detect_edid = edid;

        if (intel_dp->force_audio != HDMI_AUDIO_AUTO)
                intel_dp->has_audio = intel_dp->force_audio == HDMI_AUDIO_ON;
        else
                intel_dp->has_audio = drm_detect_monitor_audio(edid);
}

static void
intel_dp_unset_edid(struct intel_dp *intel_dp)
{
        struct intel_connector *intel_connector = intel_dp->attached_connector;

        kfree(intel_connector->detect_edid);
        intel_connector->detect_edid = NULL;

        intel_dp->has_audio = false;
}

static enum intel_display_power_domain
intel_dp_power_get(struct intel_dp *dp)
{
        struct intel_encoder *encoder = &dp_to_dig_port(dp)->base;
        enum intel_display_power_domain power_domain;

        power_domain = intel_display_port_power_domain(encoder);
        intel_display_power_get(to_i915(encoder->base.dev), power_domain);

        return power_domain;
}

static void
intel_dp_power_put(struct intel_dp *dp,
                   enum intel_display_power_domain power_domain)
{
        struct intel_encoder *encoder = &dp_to_dig_port(dp)->base;
        intel_display_power_put(to_i915(encoder->base.dev), power_domain);
}

static enum drm_connector_status
intel_dp_detect(struct drm_connector *connector, bool force)
{
        struct intel_dp *intel_dp = intel_attached_dp(connector);
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_device *dev = connector->dev;
        enum drm_connector_status status;
        enum intel_display_power_domain power_domain;
        bool ret;
        u8 sink_irq_vector;

        DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
                      connector->base.id, connector->name);
        intel_dp_unset_edid(intel_dp);

        if (intel_dp->is_mst) {
                /* MST devices are disconnected from a monitor POV */
                if (intel_encoder->type != INTEL_OUTPUT_EDP)
                        intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
                return connector_status_disconnected;
        }

        power_domain = intel_dp_power_get(intel_dp);

        /* Can't disconnect eDP, but you can close the lid... */
        if (is_edp(intel_dp))
                status = edp_detect(intel_dp);
        else if (HAS_PCH_SPLIT(dev))
                status = ironlake_dp_detect(intel_dp);
        else
                status = g4x_dp_detect(intel_dp);
        if (status != connector_status_connected)
                goto out;

        intel_dp_probe_oui(intel_dp);

        ret = intel_dp_probe_mst(intel_dp);
        if (ret) {
                /* if we are in MST mode then this connector
                   won't appear connected or have anything with EDID on it */
                if (intel_encoder->type != INTEL_OUTPUT_EDP)
                        intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
                status = connector_status_disconnected;
                goto out;
        }

        intel_dp_set_edid(intel_dp);

        if (intel_encoder->type != INTEL_OUTPUT_EDP)
                intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
        status = connector_status_connected;

        /* Try to read the source of the interrupt */
        if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
            intel_dp_get_sink_irq(intel_dp, &sink_irq_vector)) {
                /* Clear interrupt source */
                drm_dp_dpcd_writeb(&intel_dp->aux,
                                   DP_DEVICE_SERVICE_IRQ_VECTOR,
                                   sink_irq_vector);

                if (sink_irq_vector & DP_AUTOMATED_TEST_REQUEST)
                        intel_dp_handle_test_request(intel_dp);
                if (sink_irq_vector & (DP_CP_IRQ | DP_SINK_SPECIFIC_IRQ))
                        DRM_DEBUG_DRIVER("CP or sink specific irq unhandled\n");
        }

out:
        intel_dp_power_put(intel_dp, power_domain);
        return status;
}

static void
intel_dp_force(struct drm_connector *connector)
{
        struct intel_dp *intel_dp = intel_attached_dp(connector);
        struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base;
        enum intel_display_power_domain power_domain;

        DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
                      connector->base.id, connector->name);
        intel_dp_unset_edid(intel_dp);

        if (connector->status != connector_status_connected)
                return;

        power_domain = intel_dp_power_get(intel_dp);

        intel_dp_set_edid(intel_dp);

        intel_dp_power_put(intel_dp, power_domain);

        if (intel_encoder->type != INTEL_OUTPUT_EDP)
                intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
}

static int intel_dp_get_modes(struct drm_connector *connector)
{
        struct intel_connector *intel_connector = to_intel_connector(connector);
        struct edid *edid;

        edid = intel_connector->detect_edid;
        if (edid) {
                int ret = intel_connector_update_modes(connector, edid);
                if (ret)
                        return ret;
        }

        /* if eDP has no EDID, fall back to fixed mode */
        if (is_edp(intel_attached_dp(connector)) &&
            intel_connector->panel.fixed_mode) {
                struct drm_display_mode *mode;

                mode = drm_mode_duplicate(connector->dev,
                                          intel_connector->panel.fixed_mode);
                if (mode) {
                        drm_mode_probed_add(connector, mode);
                        return 1;
                }
        }

        return 0;
}

static bool
intel_dp_detect_audio(struct drm_connector *connector)
{
        bool has_audio = false;
        struct edid *edid;

        edid = to_intel_connector(connector)->detect_edid;
        if (edid)
                has_audio = drm_detect_monitor_audio(edid);

        return has_audio;
}

static int
intel_dp_set_property(struct drm_connector *connector,
                      struct drm_property *property,
                      uint64_t val)
{
        struct drm_i915_private *dev_priv = connector->dev->dev_private;
        struct intel_connector *intel_connector = to_intel_connector(connector);
        struct intel_encoder *intel_encoder = intel_attached_encoder(connector);
        struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
        int ret;

        ret = drm_object_property_set_value(&connector->base, property, val);
        if (ret)
                return ret;

        if (property == dev_priv->force_audio_property) {
                int i = val;
                bool has_audio;

                if (i == intel_dp->force_audio)
                        return 0;

                intel_dp->force_audio = i;

                if (i == HDMI_AUDIO_AUTO)
                        has_audio = intel_dp_detect_audio(connector);
                else
                        has_audio = (i == HDMI_AUDIO_ON);

                if (has_audio == intel_dp->has_audio)
                        return 0;

                intel_dp->has_audio = has_audio;
                goto done;
        }

        if (property == dev_priv->broadcast_rgb_property) {
                bool old_auto = intel_dp->color_range_auto;
                bool old_range = intel_dp->limited_color_range;

                switch (val) {
                case INTEL_BROADCAST_RGB_AUTO:
                        intel_dp->color_range_auto = true;
                        break;
                case INTEL_BROADCAST_RGB_FULL:
                        intel_dp->color_range_auto = false;
                        intel_dp->limited_color_range = false;
                        break;
                case INTEL_BROADCAST_RGB_LIMITED:
                        intel_dp->color_range_auto = false;
                        intel_dp->limited_color_range = true;
                        break;
                default:
                        return -EINVAL;
                }

                if (old_auto == intel_dp->color_range_auto &&
                    old_range == intel_dp->limited_color_range)
                        return 0;

                goto done;
        }

        if (is_edp(intel_dp) &&
            property == connector->dev->mode_config.scaling_mode_property) {
                if (val == DRM_MODE_SCALE_NONE) {
                        DRM_DEBUG_KMS("no scaling not supported\n");
                        return -EINVAL;
                }

                if (intel_connector->panel.fitting_mode == val) {
                        /* the eDP scaling property is not changed */
                        return 0;
                }
                intel_connector->panel.fitting_mode = val;

                goto done;
        }

        return -EINVAL;

done:
        if (intel_encoder->base.crtc)
                intel_crtc_restore_mode(intel_encoder->base.crtc);

        return 0;
}

static void
intel_dp_connector_destroy(struct drm_connector *connector)
{
        struct intel_connector *intel_connector = to_intel_connector(connector);

        kfree(intel_connector->detect_edid);

        if (!IS_ERR_OR_NULL(intel_connector->edid))
                kfree(intel_connector->edid);

        /* Can't call is_edp() since the encoder may have been destroyed
         * already. */
        if (connector->connector_type == DRM_MODE_CONNECTOR_eDP)
                intel_panel_fini(&intel_connector->panel);

        drm_connector_cleanup(connector);
        kfree(connector);
}

void intel_dp_encoder_destroy(struct drm_encoder *encoder)
{
        struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
        struct intel_dp *intel_dp = &intel_dig_port->dp;

        drm_dp_aux_unregister(&intel_dp->aux);
        intel_dp_mst_encoder_cleanup(intel_dig_port);
        if (is_edp(intel_dp)) {
                cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
                /*
                 * vdd might still be enabled do to the delayed vdd off.
                 * Make sure vdd is actually turned off here.
                 */
                pps_lock(intel_dp);
                edp_panel_vdd_off_sync(intel_dp);
                pps_unlock(intel_dp);

                if (intel_dp->edp_notifier.notifier_call) {
                        unregister_reboot_notifier(&intel_dp->edp_notifier);
                        intel_dp->edp_notifier.notifier_call = NULL;
                }
        }
        drm_encoder_cleanup(encoder);
        kfree(intel_dig_port);
}

static void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
{
        struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);

        if (!is_edp(intel_dp))
                return;

        /*
         * vdd might still be enabled do to the delayed vdd off.
         * Make sure vdd is actually turned off here.
         */
        cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
        pps_lock(intel_dp);
        edp_panel_vdd_off_sync(intel_dp);
        pps_unlock(intel_dp);
}

static void intel_edp_panel_vdd_sanitize(struct intel_dp *intel_dp)
{
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (!edp_have_panel_vdd(intel_dp))
                return;

        /*
         * The VDD bit needs a power domain reference, so if the bit is
         * already enabled when we boot or resume, grab this reference and
         * schedule a vdd off, so we don't hold on to the reference
         * indefinitely.
         */
        DRM_DEBUG_KMS("VDD left on by BIOS, adjusting state tracking\n");
        power_domain = intel_display_port_power_domain(&intel_dig_port->base);
        intel_display_power_get(dev_priv, power_domain);

        edp_panel_vdd_schedule_off(intel_dp);
}

static void intel_dp_encoder_reset(struct drm_encoder *encoder)
{
        struct intel_dp *intel_dp;

        if (to_intel_encoder(encoder)->type != INTEL_OUTPUT_EDP)
                return;

        intel_dp = enc_to_intel_dp(encoder);

        pps_lock(intel_dp);

        /*
         * Read out the current power sequencer assignment,
         * in case the BIOS did something with it.
         */
        if (IS_VALLEYVIEW(encoder->dev))
                vlv_initial_power_sequencer_setup(intel_dp);

        intel_edp_panel_vdd_sanitize(intel_dp);

        pps_unlock(intel_dp);
}

static const struct drm_connector_funcs intel_dp_connector_funcs = {
        .dpms = drm_atomic_helper_connector_dpms,
        .detect = intel_dp_detect,
        .force = intel_dp_force,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .set_property = intel_dp_set_property,
        .atomic_get_property = intel_connector_atomic_get_property,
        .destroy = intel_dp_connector_destroy,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
};

static const struct drm_connector_helper_funcs intel_dp_connector_helper_funcs = {
        .get_modes = intel_dp_get_modes,
        .mode_valid = intel_dp_mode_valid,
        .best_encoder = intel_best_encoder,
};

static const struct drm_encoder_funcs intel_dp_enc_funcs = {
        .reset = intel_dp_encoder_reset,
        .destroy = intel_dp_encoder_destroy,
};

enum irqreturn
intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd)
{
        struct intel_dp *intel_dp = &intel_dig_port->dp;
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_device *dev = intel_dig_port->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum intel_display_power_domain power_domain;
        enum irqreturn ret = IRQ_NONE;

        if (intel_dig_port->base.type != INTEL_OUTPUT_EDP)
                intel_dig_port->base.type = INTEL_OUTPUT_DISPLAYPORT;

        if (long_hpd && intel_dig_port->base.type == INTEL_OUTPUT_EDP) {
                /*
                 * vdd off can generate a long pulse on eDP which
                 * would require vdd on to handle it, and thus we
                 * would end up in an endless cycle of
                 * "vdd off -> long hpd -> vdd on -> detect -> vdd off -> ..."
                 */
                DRM_DEBUG_KMS("ignoring long hpd on eDP port %c\n",
                              port_name(intel_dig_port->port));
                return IRQ_HANDLED;
        }

        DRM_DEBUG_KMS("got hpd irq on port %c - %s\n",
                      port_name(intel_dig_port->port),
                      long_hpd ? "long" : "short");

        power_domain = intel_display_port_power_domain(intel_encoder);
        intel_display_power_get(dev_priv, power_domain);

        if (long_hpd) {
                /* indicate that we need to restart link training */
                intel_dp->train_set_valid = false;

                if (!intel_digital_port_connected(dev_priv, intel_dig_port))
                        goto mst_fail;

                if (!intel_dp_get_dpcd(intel_dp)) {
                        goto mst_fail;
                }

                intel_dp_probe_oui(intel_dp);

                if (!intel_dp_probe_mst(intel_dp)) {
                        drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
                        intel_dp_check_link_status(intel_dp);
                        drm_modeset_unlock(&dev->mode_config.connection_mutex);
                        goto mst_fail;
                }
        } else {
                if (intel_dp->is_mst) {
                        if (intel_dp_check_mst_status(intel_dp) == -EINVAL)
                                goto mst_fail;
                }

                if (!intel_dp->is_mst) {
                        drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
                        intel_dp_check_link_status(intel_dp);
                        drm_modeset_unlock(&dev->mode_config.connection_mutex);
                }
        }

        ret = IRQ_HANDLED;

        goto put_power;
mst_fail:
        /* if we were in MST mode, and device is not there get out of MST mode */
        if (intel_dp->is_mst) {
                DRM_DEBUG_KMS("MST device may have disappeared %d vs %d\n", intel_dp->is_mst, intel_dp->mst_mgr.mst_state);
                intel_dp->is_mst = false;
                drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);
        }
put_power:
        intel_display_power_put(dev_priv, power_domain);

        return ret;
}

/* Return which DP Port should be selected for Transcoder DP control */
int
intel_trans_dp_port_sel(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct intel_encoder *intel_encoder;
        struct intel_dp *intel_dp;

        for_each_encoder_on_crtc(dev, crtc, intel_encoder) {
                intel_dp = enc_to_intel_dp(&intel_encoder->base);

                if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
                    intel_encoder->type == INTEL_OUTPUT_EDP)
                        return intel_dp->output_reg;
        }

        return -1;
}

/* check the VBT to see whether the eDP is on another port */
bool intel_dp_is_edp(struct drm_device *dev, enum port port)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        union child_device_config *p_child;
        int i;
        static const short port_mapping[] = {
                [PORT_B] = DVO_PORT_DPB,
                [PORT_C] = DVO_PORT_DPC,
                [PORT_D] = DVO_PORT_DPD,
                [PORT_E] = DVO_PORT_DPE,
        };

        /*
         * eDP not supported on g4x. so bail out early just
         * for a bit extra safety in case the VBT is bonkers.
         */
        if (INTEL_INFO(dev)->gen < 5)
                return false;

        if (port == PORT_A)
                return true;

        if (!dev_priv->vbt.child_dev_num)
                return false;

        for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
                p_child = dev_priv->vbt.child_dev + i;

                if (p_child->common.dvo_port == port_mapping[port] &&
                    (p_child->common.device_type & DEVICE_TYPE_eDP_BITS) ==
                    (DEVICE_TYPE_eDP & DEVICE_TYPE_eDP_BITS))
                        return true;
        }
        return false;
}

void
intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connector)
{
        struct intel_connector *intel_connector = to_intel_connector(connector);

        intel_attach_force_audio_property(connector);
        intel_attach_broadcast_rgb_property(connector);
        intel_dp->color_range_auto = true;

        if (is_edp(intel_dp)) {
                drm_mode_create_scaling_mode_property(connector->dev);
                drm_object_attach_property(
                        &connector->base,
                        connector->dev->mode_config.scaling_mode_property,
                        DRM_MODE_SCALE_ASPECT);
                intel_connector->panel.fitting_mode = DRM_MODE_SCALE_ASPECT;
        }
}

static void intel_dp_init_panel_power_timestamps(struct intel_dp *intel_dp)
{
        intel_dp->last_power_cycle = jiffies;
        intel_dp->last_power_on = jiffies;
        intel_dp->last_backlight_off = jiffies;
}

static void
intel_dp_init_panel_power_sequencer(struct drm_device *dev,
                                    struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct edp_power_seq cur, vbt, spec,
                *final = &intel_dp->pps_delays;
        u32 pp_on, pp_off, pp_div = 0, pp_ctl = 0;
        int pp_ctrl_reg, pp_on_reg, pp_off_reg, pp_div_reg = 0;

        lockdep_assert_held(&dev_priv->pps_mutex);

        /* already initialized? */
        if (final->t11_t12 != 0)
                return;

        if (IS_BROXTON(dev)) {
                /*
                 * TODO: BXT has 2 sets of PPS registers.
                 * Correct Register for Broxton need to be identified
                 * using VBT. hardcoding for now
                 */
                pp_ctrl_reg = BXT_PP_CONTROL(0);
                pp_on_reg = BXT_PP_ON_DELAYS(0);
                pp_off_reg = BXT_PP_OFF_DELAYS(0);
        } else if (HAS_PCH_SPLIT(dev)) {
                pp_ctrl_reg = PCH_PP_CONTROL;
                pp_on_reg = PCH_PP_ON_DELAYS;
                pp_off_reg = PCH_PP_OFF_DELAYS;
                pp_div_reg = PCH_PP_DIVISOR;
        } else {
                enum pipe pipe = vlv_power_sequencer_pipe(intel_dp);

                pp_ctrl_reg = VLV_PIPE_PP_CONTROL(pipe);
                pp_on_reg = VLV_PIPE_PP_ON_DELAYS(pipe);
                pp_off_reg = VLV_PIPE_PP_OFF_DELAYS(pipe);
                pp_div_reg = VLV_PIPE_PP_DIVISOR(pipe);
        }

        /* Workaround: Need to write PP_CONTROL with the unlock key as
         * the very first thing. */
        pp_ctl = ironlake_get_pp_control(intel_dp);

        pp_on = I915_READ(pp_on_reg);
        pp_off = I915_READ(pp_off_reg);
        if (!IS_BROXTON(dev)) {
                I915_WRITE(pp_ctrl_reg, pp_ctl);
                pp_div = I915_READ(pp_div_reg);
        }

        /* Pull timing values out of registers */
        cur.t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
                PANEL_POWER_UP_DELAY_SHIFT;

        cur.t8 = (pp_on & PANEL_LIGHT_ON_DELAY_MASK) >>
                PANEL_LIGHT_ON_DELAY_SHIFT;

        cur.t9 = (pp_off & PANEL_LIGHT_OFF_DELAY_MASK) >>
                PANEL_LIGHT_OFF_DELAY_SHIFT;

        cur.t10 = (pp_off & PANEL_POWER_DOWN_DELAY_MASK) >>
                PANEL_POWER_DOWN_DELAY_SHIFT;

        if (IS_BROXTON(dev)) {
                u16 tmp = (pp_ctl & BXT_POWER_CYCLE_DELAY_MASK) >>
                        BXT_POWER_CYCLE_DELAY_SHIFT;
                if (tmp > 0)
                        cur.t11_t12 = (tmp - 1) * 1000;
                else
                        cur.t11_t12 = 0;
        } else {
                cur.t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
                       PANEL_POWER_CYCLE_DELAY_SHIFT) * 1000;
        }

        DRM_DEBUG_KMS("cur t1_t3 %d t8 %d t9 %d t10 %d t11_t12 %d\n",
                      cur.t1_t3, cur.t8, cur.t9, cur.t10, cur.t11_t12);

        vbt = dev_priv->vbt.edp_pps;

        /* Upper limits from eDP 1.3 spec. Note that we use the clunky units of
         * our hw here, which are all in 100usec. */
        spec.t1_t3 = 210 * 10;
        spec.t8 = 50 * 10; /* no limit for t8, use t7 instead */
        spec.t9 = 50 * 10; /* no limit for t9, make it symmetric with t8 */
        spec.t10 = 500 * 10;
        /* This one is special and actually in units of 100ms, but zero
         * based in the hw (so we need to add 100 ms). But the sw vbt
         * table multiplies it with 1000 to make it in units of 100usec,
         * too. */
        spec.t11_t12 = (510 + 100) * 10;

        DRM_DEBUG_KMS("vbt t1_t3 %d t8 %d t9 %d t10 %d t11_t12 %d\n",
                      vbt.t1_t3, vbt.t8, vbt.t9, vbt.t10, vbt.t11_t12);

        /* Use the max of the register settings and vbt. If both are
         * unset, fall back to the spec limits. */
#define assign_final(field)     final->field = (max(cur.field, vbt.field) == 0 ? \
                                       spec.field : \
                                       max(cur.field, vbt.field))
        assign_final(t1_t3);
        assign_final(t8);
        assign_final(t9);
        assign_final(t10);
        assign_final(t11_t12);
#undef assign_final

#define get_delay(field)        (DIV_ROUND_UP(final->field, 10))
        intel_dp->panel_power_up_delay = get_delay(t1_t3);
        intel_dp->backlight_on_delay = get_delay(t8);
        intel_dp->backlight_off_delay = get_delay(t9);
        intel_dp->panel_power_down_delay = get_delay(t10);
        intel_dp->panel_power_cycle_delay = get_delay(t11_t12);
#undef get_delay

        DRM_DEBUG_KMS("panel power up delay %d, power down delay %d, power cycle delay %d\n",
                      intel_dp->panel_power_up_delay, intel_dp->panel_power_down_delay,
                      intel_dp->panel_power_cycle_delay);

        DRM_DEBUG_KMS("backlight on delay %d, off delay %d\n",
                      intel_dp->backlight_on_delay, intel_dp->backlight_off_delay);
}

static void
intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
                                              struct intel_dp *intel_dp)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 pp_on, pp_off, pp_div, port_sel = 0;
        int div = HAS_PCH_SPLIT(dev) ? intel_pch_rawclk(dev) : intel_hrawclk(dev);
        int pp_on_reg, pp_off_reg, pp_div_reg = 0, pp_ctrl_reg;
        enum port port = dp_to_dig_port(intel_dp)->port;
        const struct edp_power_seq *seq = &intel_dp->pps_delays;

        lockdep_assert_held(&dev_priv->pps_mutex);

        if (IS_BROXTON(dev)) {
                /*
                 * TODO: BXT has 2 sets of PPS registers.
                 * Correct Register for Broxton need to be identified
                 * using VBT. hardcoding for now
                 */
                pp_ctrl_reg = BXT_PP_CONTROL(0);
                pp_on_reg = BXT_PP_ON_DELAYS(0);
                pp_off_reg = BXT_PP_OFF_DELAYS(0);

        } else if (HAS_PCH_SPLIT(dev)) {
                pp_on_reg = PCH_PP_ON_DELAYS;
                pp_off_reg = PCH_PP_OFF_DELAYS;
                pp_div_reg = PCH_PP_DIVISOR;
        } else {
                enum pipe pipe = vlv_power_sequencer_pipe(intel_dp);

                pp_on_reg = VLV_PIPE_PP_ON_DELAYS(pipe);
                pp_off_reg = VLV_PIPE_PP_OFF_DELAYS(pipe);
                pp_div_reg = VLV_PIPE_PP_DIVISOR(pipe);
        }

        /*
         * And finally store the new values in the power sequencer. The
         * backlight delays are set to 1 because we do manual waits on them. For
         * T8, even BSpec recommends doing it. For T9, if we don't do this,
         * we'll end up waiting for the backlight off delay twice: once when we
         * do the manual sleep, and once when we disable the panel and wait for
         * the PP_STATUS bit to become zero.
         */
        pp_on = (seq->t1_t3 << PANEL_POWER_UP_DELAY_SHIFT) |
                (1 << PANEL_LIGHT_ON_DELAY_SHIFT);
        pp_off = (1 << PANEL_LIGHT_OFF_DELAY_SHIFT) |
                 (seq->t10 << PANEL_POWER_DOWN_DELAY_SHIFT);
        /* Compute the divisor for the pp clock, simply match the Bspec
         * formula. */
        if (IS_BROXTON(dev)) {
                pp_div = I915_READ(pp_ctrl_reg);
                pp_div &= ~BXT_POWER_CYCLE_DELAY_MASK;
                pp_div |= (DIV_ROUND_UP((seq->t11_t12 + 1), 1000)
                                << BXT_POWER_CYCLE_DELAY_SHIFT);
        } else {
                pp_div = ((100 * div)/2 - 1) << PP_REFERENCE_DIVIDER_SHIFT;
                pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000)
                                << PANEL_POWER_CYCLE_DELAY_SHIFT);
        }

        /* Haswell doesn't have any port selection bits for the panel
         * power sequencer any more. */
        if (IS_VALLEYVIEW(dev)) {
                port_sel = PANEL_PORT_SELECT_VLV(port);
        } else if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev)) {
                if (port == PORT_A)
                        port_sel = PANEL_PORT_SELECT_DPA;
                else
                        port_sel = PANEL_PORT_SELECT_DPD;
        }

        pp_on |= port_sel;

        I915_WRITE(pp_on_reg, pp_on);
        I915_WRITE(pp_off_reg, pp_off);
        if (IS_BROXTON(dev))
                I915_WRITE(pp_ctrl_reg, pp_div);
        else
                I915_WRITE(pp_div_reg, pp_div);

        DRM_DEBUG_KMS("panel power sequencer register settings: PP_ON %#x, PP_OFF %#x, PP_DIV %#x\n",
                      I915_READ(pp_on_reg),
                      I915_READ(pp_off_reg),
                      IS_BROXTON(dev) ?
                      (I915_READ(pp_ctrl_reg) & BXT_POWER_CYCLE_DELAY_MASK) :
                      I915_READ(pp_div_reg));
}

/**
 * intel_dp_set_drrs_state - program registers for RR switch to take effect
 * @dev: DRM device
 * @refresh_rate: RR to be programmed
 *
 * This function gets called when refresh rate (RR) has to be changed from
 * one frequency to another. Switches can be between high and low RR
 * supported by the panel or to any other RR based on media playback (in
 * this case, RR value needs to be passed from user space).
 *
 * The caller of this function needs to take a lock on dev_priv->drrs.
 */
static void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_encoder *encoder;
        struct intel_digital_port *dig_port = NULL;
        struct intel_dp *intel_dp = dev_priv->drrs.dp;
        struct intel_crtc_state *config = NULL;
        struct intel_crtc *intel_crtc = NULL;
        enum drrs_refresh_rate_type index = DRRS_HIGH_RR;

        if (refresh_rate <= 0) {
                DRM_DEBUG_KMS("Refresh rate should be positive non-zero.\n");
                return;
        }

        if (intel_dp == NULL) {
                DRM_DEBUG_KMS("DRRS not supported.\n");
                return;
        }

        /*
         * FIXME: This needs proper synchronization with psr state for some
         * platforms that cannot have PSR and DRRS enabled at the same time.
         */

        dig_port = dp_to_dig_port(intel_dp);
        encoder = &dig_port->base;
        intel_crtc = to_intel_crtc(encoder->base.crtc);

        if (!intel_crtc) {
                DRM_DEBUG_KMS("DRRS: intel_crtc not initialized\n");
                return;
        }

        config = intel_crtc->config;

        if (dev_priv->drrs.type < SEAMLESS_DRRS_SUPPORT) {
                DRM_DEBUG_KMS("Only Seamless DRRS supported.\n");
                return;
        }

        if (intel_dp->attached_connector->panel.downclock_mode->vrefresh ==
                        refresh_rate)
                index = DRRS_LOW_RR;

        if (index == dev_priv->drrs.refresh_rate_type) {
                DRM_DEBUG_KMS(
                        "DRRS requested for previously set RR...ignoring\n");
                return;
        }

        if (!intel_crtc->active) {
                DRM_DEBUG_KMS("eDP encoder disabled. CRTC not Active\n");
                return;
        }

        if (INTEL_INFO(dev)->gen >= 8 && !IS_CHERRYVIEW(dev)) {
                switch (index) {
                case DRRS_HIGH_RR:
                        intel_dp_set_m_n(intel_crtc, M1_N1);
                        break;
                case DRRS_LOW_RR:
                        intel_dp_set_m_n(intel_crtc, M2_N2);
                        break;
                case DRRS_MAX_RR:
                default:
                        DRM_ERROR("Unsupported refreshrate type\n");
                }
        } else if (INTEL_INFO(dev)->gen > 6) {
                u32 reg = PIPECONF(intel_crtc->config->cpu_transcoder);
                u32 val;

                val = I915_READ(reg);
                if (index > DRRS_HIGH_RR) {
                        if (IS_VALLEYVIEW(dev))
                                val |= PIPECONF_EDP_RR_MODE_SWITCH_VLV;
                        else
                                val |= PIPECONF_EDP_RR_MODE_SWITCH;
                } else {
                        if (IS_VALLEYVIEW(dev))
                                val &= ~PIPECONF_EDP_RR_MODE_SWITCH_VLV;
                        else
                                val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
                }
                I915_WRITE(reg, val);
        }

        dev_priv->drrs.refresh_rate_type = index;

        DRM_DEBUG_KMS("eDP Refresh Rate set to : %dHz\n", refresh_rate);
}

/**
 * intel_edp_drrs_enable - init drrs struct if supported
 * @intel_dp: DP struct
 *
 * Initializes frontbuffer_bits and drrs.dp
 */
void intel_edp_drrs_enable(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_crtc *crtc = dig_port->base.base.crtc;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);

        if (!intel_crtc->config->has_drrs) {
                DRM_DEBUG_KMS("Panel doesn't support DRRS\n");
                return;
        }

        mutex_lock(&dev_priv->drrs.mutex);
        if (WARN_ON(dev_priv->drrs.dp)) {
                DRM_ERROR("DRRS already enabled\n");
                goto unlock;
        }

        dev_priv->drrs.busy_frontbuffer_bits = 0;

        dev_priv->drrs.dp = intel_dp;

unlock:
        mutex_unlock(&dev_priv->drrs.mutex);
}

/**
 * intel_edp_drrs_disable - Disable DRRS
 * @intel_dp: DP struct
 *
 */
void intel_edp_drrs_disable(struct intel_dp *intel_dp)
{
        struct drm_device *dev = intel_dp_to_dev(intel_dp);
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
        struct drm_crtc *crtc = dig_port->base.base.crtc;
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);

        if (!intel_crtc->config->has_drrs)
                return;

        mutex_lock(&dev_priv->drrs.mutex);
        if (!dev_priv->drrs.dp) {
                mutex_unlock(&dev_priv->drrs.mutex);
                return;
        }

        if (dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
                intel_dp_set_drrs_state(dev_priv->dev,
                        intel_dp->attached_connector->panel.
                        fixed_mode->vrefresh);

        dev_priv->drrs.dp = NULL;
        mutex_unlock(&dev_priv->drrs.mutex);

        cancel_delayed_work_sync(&dev_priv->drrs.work);
}

static void intel_edp_drrs_downclock_work(struct work_struct *work)
{
        struct drm_i915_private *dev_priv =
                container_of(work, typeof(*dev_priv), drrs.work.work);
        struct intel_dp *intel_dp;

        mutex_lock(&dev_priv->drrs.mutex);

        intel_dp = dev_priv->drrs.dp;

        if (!intel_dp)
                goto unlock;

        /*
         * The delayed work can race with an invalidate hence we need to
         * recheck.
         */

        if (dev_priv->drrs.busy_frontbuffer_bits)
                goto unlock;

        if (dev_priv->drrs.refresh_rate_type != DRRS_LOW_RR)
                intel_dp_set_drrs_state(dev_priv->dev,
                        intel_dp->attached_connector->panel.
                        downclock_mode->vrefresh);

unlock:
        mutex_unlock(&dev_priv->drrs.mutex);
}

/**
 * intel_edp_drrs_invalidate - Disable Idleness DRRS
 * @dev: DRM device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 *
 * This function gets called everytime rendering on the given planes start.
 * Hence DRRS needs to be Upclocked, i.e. (LOW_RR -> HIGH_RR).
 *
 * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
 */
void intel_edp_drrs_invalidate(struct drm_device *dev,
                unsigned frontbuffer_bits)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc;
        enum pipe pipe;

        if (dev_priv->drrs.type == DRRS_NOT_SUPPORTED)
                return;

        cancel_delayed_work(&dev_priv->drrs.work);

        mutex_lock(&dev_priv->drrs.mutex);
        if (!dev_priv->drrs.dp) {
                mutex_unlock(&dev_priv->drrs.mutex);
                return;
        }

        crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
        pipe = to_intel_crtc(crtc)->pipe;

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
        dev_priv->drrs.busy_frontbuffer_bits |= frontbuffer_bits;

        /* invalidate means busy screen hence upclock */
        if (frontbuffer_bits && dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
                intel_dp_set_drrs_state(dev_priv->dev,
                                dev_priv->drrs.dp->attached_connector->panel.
                                fixed_mode->vrefresh);

        mutex_unlock(&dev_priv->drrs.mutex);
}

/**
 * intel_edp_drrs_flush - Restart Idleness DRRS
 * @dev: DRM device
 * @frontbuffer_bits: frontbuffer plane tracking bits
 *
 * This function gets called every time rendering on the given planes has
 * completed or flip on a crtc is completed. So DRRS should be upclocked
 * (LOW_RR -> HIGH_RR). And also Idleness detection should be started again,
 * if no other planes are dirty.
 *
 * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
 */
void intel_edp_drrs_flush(struct drm_device *dev,
                unsigned frontbuffer_bits)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_crtc *crtc;
        enum pipe pipe;

        if (dev_priv->drrs.type == DRRS_NOT_SUPPORTED)
                return;

        cancel_delayed_work(&dev_priv->drrs.work);

        mutex_lock(&dev_priv->drrs.mutex);
        if (!dev_priv->drrs.dp) {
                mutex_unlock(&dev_priv->drrs.mutex);
                return;
        }

        crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
        pipe = to_intel_crtc(crtc)->pipe;

        frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
        dev_priv->drrs.busy_frontbuffer_bits &= ~frontbuffer_bits;

        /* flush means busy screen hence upclock */
        if (frontbuffer_bits && dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
                intel_dp_set_drrs_state(dev_priv->dev,
                                dev_priv->drrs.dp->attached_connector->panel.
                                fixed_mode->vrefresh);

        /*
         * flush also means no more activity hence schedule downclock, if all
         * other fbs are quiescent too
         */
        if (!dev_priv->drrs.busy_frontbuffer_bits)
                schedule_delayed_work(&dev_priv->drrs.work,
                                msecs_to_jiffies(1000));
        mutex_unlock(&dev_priv->drrs.mutex);
}

/**
 * DOC: Display Refresh Rate Switching (DRRS)
 *
 * Display Refresh Rate Switching (DRRS) is a power conservation feature
 * which enables swtching between low and high refresh rates,
 * dynamically, based on the usage scenario. This feature is applicable
 * for internal panels.
 *
 * Indication that the panel supports DRRS is given by the panel EDID, which
 * would list multiple refresh rates for one resolution.
 *
 * DRRS is of 2 types - static and seamless.
 * Static DRRS involves changing refresh rate (RR) by doing a full modeset
 * (may appear as a blink on screen) and is used in dock-undock scenario.
 * Seamless DRRS involves changing RR without any visual effect to the user
 * and can be used during normal system usage. This is done by programming
 * certain registers.
 *
 * Support for static/seamless DRRS may be indicated in the VBT based on
 * inputs from the panel spec.
 *
 * DRRS saves power by switching to low RR based on usage scenarios.
 *
 * eDP DRRS:-
 *        The implementation is based on frontbuffer tracking implementation.
 * When there is a disturbance on the screen triggered by user activity or a
 * periodic system activity, DRRS is disabled (RR is changed to high RR).
 * When there is no movement on screen, after a timeout of 1 second, a switch
 * to low RR is made.
 *        For integration with frontbuffer tracking code,
 * intel_edp_drrs_invalidate() and intel_edp_drrs_flush() are called.
 *
 * DRRS can be further extended to support other internal panels and also
 * the scenario of video playback wherein RR is set based on the rate
 * requested by userspace.
 */

/**
 * intel_dp_drrs_init - Init basic DRRS work and mutex.
 * @intel_connector: eDP connector
 * @fixed_mode: preferred mode of panel
 *
 * This function is  called only once at driver load to initialize basic
 * DRRS stuff.
 *
 * Returns:
 * Downclock mode if panel supports it, else return NULL.
 * DRRS support is determined by the presence of downclock mode (apart
 * from VBT setting).
 */
static struct drm_display_mode *
intel_dp_drrs_init(struct intel_connector *intel_connector,
                struct drm_display_mode *fixed_mode)
{
        struct drm_connector *connector = &intel_connector->base;
        struct drm_device *dev = connector->dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_display_mode *downclock_mode = NULL;

        INIT_DELAYED_WORK(&dev_priv->drrs.work, intel_edp_drrs_downclock_work);
        mutex_init(&dev_priv->drrs.mutex);

        if (INTEL_INFO(dev)->gen <= 6) {
                DRM_DEBUG_KMS("DRRS supported for Gen7 and above\n");
                return NULL;
        }

        if (dev_priv->vbt.drrs_type != SEAMLESS_DRRS_SUPPORT) {
                DRM_DEBUG_KMS("VBT doesn't support DRRS\n");
                return NULL;
        }

        downclock_mode = intel_find_panel_downclock
                                        (dev, fixed_mode, connector);

        if (!downclock_mode) {
                DRM_DEBUG_KMS("Downclock mode is not found. DRRS not supported\n");
                return NULL;
        }

        dev_priv->drrs.type = dev_priv->vbt.drrs_type;

        dev_priv->drrs.refresh_rate_type = DRRS_HIGH_RR;
        DRM_DEBUG_KMS("seamless DRRS supported for eDP panel.\n");
        return downclock_mode;
}

static bool intel_edp_init_connector(struct intel_dp *intel_dp,
                                     struct intel_connector *intel_connector)
{
        struct drm_connector *connector = &intel_connector->base;
        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_device *dev = intel_encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_display_mode *fixed_mode = NULL;
        struct drm_display_mode *downclock_mode = NULL;
        bool has_dpcd;
        struct drm_display_mode *scan;
        struct edid *edid;
        enum pipe pipe = INVALID_PIPE;

        if (!is_edp(intel_dp))
                return true;

        pps_lock(intel_dp);
        intel_edp_panel_vdd_sanitize(intel_dp);
        pps_unlock(intel_dp);

        /* Cache DPCD and EDID for edp. */
        has_dpcd = intel_dp_get_dpcd(intel_dp);

        if (has_dpcd) {
                if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11)
                        dev_priv->no_aux_handshake =
                                intel_dp->dpcd[DP_MAX_DOWNSPREAD] &
                                DP_NO_AUX_HANDSHAKE_LINK_TRAINING;
        } else {
                /* if this fails, presume the device is a ghost */
                DRM_INFO("failed to retrieve link info, disabling eDP\n");
                return false;
        }

        /* We now know it's not a ghost, init power sequence regs. */
        pps_lock(intel_dp);
        intel_dp_init_panel_power_sequencer_registers(dev, intel_dp);
        pps_unlock(intel_dp);

        mutex_lock(&dev->mode_config.mutex);
        edid = drm_get_edid(connector, &intel_dp->aux.ddc);
        if (edid) {
                if (drm_add_edid_modes(connector, edid)) {
                        drm_mode_connector_update_edid_property(connector,
                                                                edid);
                        drm_edid_to_eld(connector, edid);
                } else {
                        kfree(edid);
                        edid = ERR_PTR(-EINVAL);
                }
        } else {
                edid = ERR_PTR(-ENOENT);
        }
        intel_connector->edid = edid;

        /* prefer fixed mode from EDID if available */
        list_for_each_entry(scan, &connector->probed_modes, head) {
                if ((scan->type & DRM_MODE_TYPE_PREFERRED)) {
                        fixed_mode = drm_mode_duplicate(dev, scan);
                        downclock_mode = intel_dp_drrs_init(
                                                intel_connector, fixed_mode);
                        break;
                }
        }

        /* fallback to VBT if available for eDP */
        if (!fixed_mode && dev_priv->vbt.lfp_lvds_vbt_mode) {
                fixed_mode = drm_mode_duplicate(dev,
                                        dev_priv->vbt.lfp_lvds_vbt_mode);
                if (fixed_mode)
                        fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
        }
        mutex_unlock(&dev->mode_config.mutex);

        if (IS_VALLEYVIEW(dev)) {
                intel_dp->edp_notifier.notifier_call = edp_notify_handler;
                register_reboot_notifier(&intel_dp->edp_notifier);

                /*
                 * Figure out the current pipe for the initial backlight setup.
                 * If the current pipe isn't valid, try the PPS pipe, and if that
                 * fails just assume pipe A.
                 */
                if (IS_CHERRYVIEW(dev))
                        pipe = DP_PORT_TO_PIPE_CHV(intel_dp->DP);
                else
                        pipe = PORT_TO_PIPE(intel_dp->DP);

                if (pipe != PIPE_A && pipe != PIPE_B)
                        pipe = intel_dp->pps_pipe;

                if (pipe != PIPE_A && pipe != PIPE_B)
                        pipe = PIPE_A;

                DRM_DEBUG_KMS("using pipe %c for initial backlight setup\n",
                              pipe_name(pipe));
        }

        intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode);
        intel_connector->panel.backlight.power = intel_edp_backlight_power;
        intel_panel_setup_backlight(connector, pipe);

        return true;
}

bool
intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
                        struct intel_connector *intel_connector)
{
        struct drm_connector *connector = &intel_connector->base;
        struct intel_dp *intel_dp = &intel_dig_port->dp;
        struct intel_encoder *intel_encoder = &intel_dig_port->base;
        struct drm_device *dev = intel_encoder->base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
        enum port port = intel_dig_port->port;
        int type;

        intel_dp->pps_pipe = INVALID_PIPE;

        /* intel_dp vfuncs */
        if (INTEL_INFO(dev)->gen >= 9)
                intel_dp->get_aux_clock_divider = skl_get_aux_clock_divider;
        else if (IS_VALLEYVIEW(dev))
                intel_dp->get_aux_clock_divider = vlv_get_aux_clock_divider;
        else if (IS_HASWELL(dev) || IS_BROADWELL(dev))
                intel_dp->get_aux_clock_divider = hsw_get_aux_clock_divider;
        else if (HAS_PCH_SPLIT(dev))
                intel_dp->get_aux_clock_divider = ilk_get_aux_clock_divider;
        else
                intel_dp->get_aux_clock_divider = i9xx_get_aux_clock_divider;

        if (INTEL_INFO(dev)->gen >= 9)
                intel_dp->get_aux_send_ctl = skl_get_aux_send_ctl;
        else
                intel_dp->get_aux_send_ctl = i9xx_get_aux_send_ctl;

        /* Preserve the current hw state. */
        intel_dp->DP = I915_READ(intel_dp->output_reg);
        intel_dp->attached_connector = intel_connector;

        if (intel_dp_is_edp(dev, port))
                type = DRM_MODE_CONNECTOR_eDP;
        else
                type = DRM_MODE_CONNECTOR_DisplayPort;

        /*
         * For eDP we always set the encoder type to INTEL_OUTPUT_EDP, but
         * for DP the encoder type can be set by the caller to
         * INTEL_OUTPUT_UNKNOWN for DDI, so don't rewrite it.
         */
        if (type == DRM_MODE_CONNECTOR_eDP)
                intel_encoder->type = INTEL_OUTPUT_EDP;

        /* eDP only on port B and/or C on vlv/chv */
        if (WARN_ON(IS_VALLEYVIEW(dev) && is_edp(intel_dp) &&
                    port != PORT_B && port != PORT_C))
                return false;

        DRM_DEBUG_KMS("Adding %s connector on port %c\n",
                        type == DRM_MODE_CONNECTOR_eDP ? "eDP" : "DP",
                        port_name(port));

        drm_connector_init(dev, connector, &intel_dp_connector_funcs, type);
        drm_connector_helper_add(connector, &intel_dp_connector_helper_funcs);

        connector->interlace_allowed = true;
        connector->doublescan_allowed = 0;

        INIT_DELAYED_WORK(&intel_dp->panel_vdd_work,
                          edp_panel_vdd_work);

        intel_connector_attach_encoder(intel_connector, intel_encoder);
        drm_connector_register(connector);

        if (HAS_DDI(dev))
                intel_connector->get_hw_state = intel_ddi_connector_get_hw_state;
        else
                intel_connector->get_hw_state = intel_connector_get_hw_state;
        intel_connector->unregister = intel_dp_connector_unregister;

        /* Set up the hotplug pin. */
        switch (port) {
        case PORT_A:
                intel_encoder->hpd_pin = HPD_PORT_A;
                break;
        case PORT_B:
                intel_encoder->hpd_pin = HPD_PORT_B;
                if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
                        intel_encoder->hpd_pin = HPD_PORT_A;
                break;
        case PORT_C:
                intel_encoder->hpd_pin = HPD_PORT_C;
                break;
        case PORT_D:
                intel_encoder->hpd_pin = HPD_PORT_D;
                break;
        case PORT_E:
                intel_encoder->hpd_pin = HPD_PORT_E;
                break;
        default:
                BUG();
        }

        if (is_edp(intel_dp)) {
                pps_lock(intel_dp);
                intel_dp_init_panel_power_timestamps(intel_dp);
                if (IS_VALLEYVIEW(dev))
                        vlv_initial_power_sequencer_setup(intel_dp);
                else
                        intel_dp_init_panel_power_sequencer(dev, intel_dp);
                pps_unlock(intel_dp);
        }

        intel_dp_aux_init(intel_dp, intel_connector);

        /* init MST on ports that can support it */
        if (HAS_DP_MST(dev) &&
            (port == PORT_B || port == PORT_C || port == PORT_D))
                intel_dp_mst_encoder_init(intel_dig_port,
                                          intel_connector->base.base.id);

        if (!intel_edp_init_connector(intel_dp, intel_connector)) {
                drm_dp_aux_unregister(&intel_dp->aux);
                if (is_edp(intel_dp)) {
                        cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
                        /*
                         * vdd might still be enabled do to the delayed vdd off.
                         * Make sure vdd is actually turned off here.
                         */
                        pps_lock(intel_dp);
                        edp_panel_vdd_off_sync(intel_dp);
                        pps_unlock(intel_dp);
                }
                drm_connector_unregister(connector);
                drm_connector_cleanup(connector);
                return false;
        }

        intel_dp_add_properties(intel_dp, connector);

        /* For G4X desktop chip, PEG_BAND_GAP_DATA 3:0 must first be written
         * 0xd.  Failure to do so will result in spurious interrupts being
         * generated on the port when a cable is not attached.
         */
        if (IS_G4X(dev) && !IS_GM45(dev)) {
                u32 temp = I915_READ(PEG_BAND_GAP_DATA);
                I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd);
        }

        i915_debugfs_connector_add(connector);

        return true;
}

void
intel_dp_init(struct drm_device *dev, int output_reg, enum port port)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct intel_digital_port *intel_dig_port;
        struct intel_encoder *intel_encoder;
        struct drm_encoder *encoder;
        struct intel_connector *intel_connector;

        intel_dig_port = kzalloc(sizeof(*intel_dig_port), GFP_KERNEL);
        if (!intel_dig_port)
                return;

        intel_connector = intel_connector_alloc();
        if (!intel_connector)
                goto err_connector_alloc;

        intel_encoder = &intel_dig_port->base;
        encoder = &intel_encoder->base;

        drm_encoder_init(dev, &intel_encoder->base, &intel_dp_enc_funcs,
                         DRM_MODE_ENCODER_TMDS);

        intel_encoder->compute_config = intel_dp_compute_config;
        intel_encoder->disable = intel_disable_dp;
        intel_encoder->get_hw_state = intel_dp_get_hw_state;
        intel_encoder->get_config = intel_dp_get_config;
        intel_encoder->suspend = intel_dp_encoder_suspend;
        if (IS_CHERRYVIEW(dev)) {
                intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
                intel_encoder->pre_enable = chv_pre_enable_dp;
                intel_encoder->enable = vlv_enable_dp;
                intel_encoder->post_disable = chv_post_disable_dp;
                intel_encoder->post_pll_disable = chv_dp_post_pll_disable;
        } else if (IS_VALLEYVIEW(dev)) {
                intel_encoder->pre_pll_enable = vlv_dp_pre_pll_enable;
                intel_encoder->pre_enable = vlv_pre_enable_dp;
                intel_encoder->enable = vlv_enable_dp;
                intel_encoder->post_disable = vlv_post_disable_dp;
        } else {
                intel_encoder->pre_enable = g4x_pre_enable_dp;
                intel_encoder->enable = g4x_enable_dp;
                if (INTEL_INFO(dev)->gen >= 5)
                        intel_encoder->post_disable = ilk_post_disable_dp;
        }

        intel_dig_port->port = port;
        intel_dig_port->dp.output_reg = output_reg;

        intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
        if (IS_CHERRYVIEW(dev)) {
                if (port == PORT_D)
                        intel_encoder->crtc_mask = 1 << 2;
                else
                        intel_encoder->crtc_mask = (1 << 0) | (1 << 1);
        } else {
                intel_encoder->crtc_mask = (1 << 0) | (1 << 1) | (1 << 2);
        }
        intel_encoder->cloneable = 0;

        intel_dig_port->hpd_pulse = intel_dp_hpd_pulse;
        dev_priv->hotplug.irq_port[port] = intel_dig_port;

        if (!intel_dp_init_connector(intel_dig_port, intel_connector))
                goto err_init_connector;

        return;

err_init_connector:
        drm_encoder_cleanup(encoder);
        kfree(intel_connector);
err_connector_alloc:
        kfree(intel_dig_port);

        return;
}

void intel_dp_mst_suspend(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int i;

        /* disable MST */
        for (i = 0; i < I915_MAX_PORTS; i++) {
                struct intel_digital_port *intel_dig_port = dev_priv->hotplug.irq_port[i];
                if (!intel_dig_port)
                        continue;

                if (intel_dig_port->base.type == INTEL_OUTPUT_DISPLAYPORT) {
                        if (!intel_dig_port->dp.can_mst)
                                continue;
                        if (intel_dig_port->dp.is_mst)
                                drm_dp_mst_topology_mgr_suspend(&intel_dig_port->dp.mst_mgr);
                }
        }
}

void intel_dp_mst_resume(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        int i;

        for (i = 0; i < I915_MAX_PORTS; i++) {
                struct intel_digital_port *intel_dig_port = dev_priv->hotplug.irq_port[i];
                if (!intel_dig_port)
                        continue;
                if (intel_dig_port->base.type == INTEL_OUTPUT_DISPLAYPORT) {
                        int ret;

                        if (!intel_dig_port->dp.can_mst)
                                continue;

                        ret = drm_dp_mst_topology_mgr_resume(&intel_dig_port->dp.mst_mgr);
                        if (ret != 0) {
                                intel_dp_check_mst_status(&intel_dig_port->dp);
                        }
                }
        }
}