From: Suraj Kandpal <suraj.kandpal@intel.com>
Date: Sat, 1 Nov 2025 03:24:53 +0000 (+0530)
Subject: drm/i915/ltphy: Program sequence for PORT_CLOCK_CTL for LT Phy
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3a323c7e96507773733d77d4a898ea7dbd2c157e;p=thirdparty%2Fkernel%2Flinux.git

drm/i915/ltphy: Program sequence for PORT_CLOCK_CTL for LT Phy

Program sequence from port clock ctl except for the SSC
enablement part which will be taken care of later.

Bspec: 74492
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Link: https://patch.msgid.link/20251101032513.4171255-6-suraj.kandpal@intel.com
---

diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.h b/drivers/gpu/drm/i915/display/intel_cx0_phy.h
index c92026fe7b8f1..b111a893b4288 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.h
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.h
@@ -43,6 +43,7 @@ void intel_cx0_phy_set_signal_levels(struct intel_encoder *encoder,
 				     const struct intel_crtc_state *crtc_state);
 int intel_cx0_phy_check_hdmi_link_rate(struct intel_hdmi *hdmi, int clock);
 void intel_cx0_setup_powerdown(struct intel_encoder *encoder);
+bool intel_cx0_is_hdmi_frl(u32 clock);
 int intel_mtl_tbt_calc_port_clock(struct intel_encoder *encoder);
 void intel_cx0_pll_power_save_wa(struct intel_display *display);
 void intel_lnl_mac_transmit_lfps(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy.c b/drivers/gpu/drm/i915/display/intel_lt_phy.c
index c65333cc9494f..b6f71425cd195 100644
--- a/drivers/gpu/drm/i915/display/intel_lt_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_lt_phy.c
@@ -11,6 +11,7 @@
 #include "intel_de.h"
 #include "intel_display.h"
 #include "intel_display_types.h"
+#include "intel_hdmi.h"
 #include "intel_lt_phy.h"
 #include "intel_lt_phy_regs.h"
 #include "intel_tc.h"
@@ -108,13 +109,49 @@ intel_lt_phy_lane_reset(struct intel_encoder *encoder,
 	intel_de_rmw(display, XELPDP_PORT_BUF_CTL2(display, port), lane_phy_pulse_status, 0);
 }
 
+static void
+intel_lt_phy_program_port_clock_ctl(struct intel_encoder *encoder,
+				    const struct intel_crtc_state *crtc_state,
+				    bool lane_reversal)
+{
+	struct intel_display *display = to_intel_display(encoder);
+	u32 val = 0;
+
+	intel_de_rmw(display, XELPDP_PORT_BUF_CTL1(display, encoder->port),
+		     XELPDP_PORT_REVERSAL,
+		     lane_reversal ? XELPDP_PORT_REVERSAL : 0);
+
+	val |= XELPDP_FORWARD_CLOCK_UNGATE;
+
+	/*
+	 * We actually mean MACCLK here and not MAXPCLK when using LT Phy
+	 * but since the register bits still remain the same we use
+	 * the same definition
+	 */
+	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI) &&
+	    intel_hdmi_is_frl(crtc_state->port_clock))
+		val |= XELPDP_DDI_CLOCK_SELECT_PREP(display, XELPDP_DDI_CLOCK_SELECT_DIV18CLK);
+	else
+		val |= XELPDP_DDI_CLOCK_SELECT_PREP(display, XELPDP_DDI_CLOCK_SELECT_MAXPCLK);
+
+	intel_de_rmw(display, XELPDP_PORT_CLOCK_CTL(display, encoder->port),
+		     XELPDP_LANE1_PHY_CLOCK_SELECT | XELPDP_FORWARD_CLOCK_UNGATE |
+		     XELPDP_DDI_CLOCK_SELECT_MASK(display) | XELPDP_SSC_ENABLE_PLLA |
+		     XELPDP_SSC_ENABLE_PLLB, val);
+}
+
 void intel_lt_phy_pll_enable(struct intel_encoder *encoder,
 			     const struct intel_crtc_state *crtc_state)
 {
+	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
+	bool lane_reversal = dig_port->lane_reversal;
+
 	/* 1. Enable MacCLK at default 162 MHz frequency. */
 	intel_lt_phy_lane_reset(encoder, crtc_state->lane_count);
 
 	/* 2. Program PORT_CLOCK_CTL register to configure clock muxes, gating, and SSC. */
+	intel_lt_phy_program_port_clock_ctl(encoder, crtc_state, lane_reversal);
+
 	/* 3. Change owned PHY lanes power to Ready state. */
 	/*
 	 * 4. Read the PHY message bus VDR register PHY_VDR_0_Config check enabled PLL type,