Merge tag 'staging-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[thirdparty/linux.git] / drivers / dma / tegra210-adma.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ADMA driver for Nvidia's Tegra210 ADMA controller.
 *
 * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/clk.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/of_irq.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include "virt-dma.h"

#define ADMA_CH_CMD                                     0x00
#define ADMA_CH_STATUS                                  0x0c
#define ADMA_CH_STATUS_XFER_EN                          BIT(0)
#define ADMA_CH_STATUS_XFER_PAUSED                      BIT(1)

#define ADMA_CH_INT_STATUS                              0x10
#define ADMA_CH_INT_STATUS_XFER_DONE                    BIT(0)

#define ADMA_CH_INT_CLEAR                               0x1c
#define ADMA_CH_CTRL                                    0x24
#define ADMA_CH_CTRL_DIR(val)                           (((val) & 0xf) << 12)
#define ADMA_CH_CTRL_DIR_AHUB2MEM                       2
#define ADMA_CH_CTRL_DIR_MEM2AHUB                       4
#define ADMA_CH_CTRL_MODE_CONTINUOUS                    (2 << 8)
#define ADMA_CH_CTRL_FLOWCTRL_EN                        BIT(1)
#define ADMA_CH_CTRL_XFER_PAUSE_SHIFT                   0

#define ADMA_CH_CONFIG                                  0x28
#define ADMA_CH_CONFIG_SRC_BUF(val)                     (((val) & 0x7) << 28)
#define ADMA_CH_CONFIG_TRG_BUF(val)                     (((val) & 0x7) << 24)
#define ADMA_CH_CONFIG_BURST_SIZE_SHIFT                 20
#define ADMA_CH_CONFIG_MAX_BURST_SIZE                   16
#define ADMA_CH_CONFIG_WEIGHT_FOR_WRR(val)              ((val) & 0xf)
#define ADMA_CH_CONFIG_MAX_BUFS                         8

#define ADMA_CH_FIFO_CTRL                               0x2c
#define TEGRA210_ADMA_CH_FIFO_CTRL_OFLWTHRES(val)       (((val) & 0xf) << 24)
#define TEGRA210_ADMA_CH_FIFO_CTRL_STRVTHRES(val)       (((val) & 0xf) << 16)
#define TEGRA210_ADMA_CH_FIFO_CTRL_TXSIZE(val)          (((val) & 0xf) << 8)
#define TEGRA210_ADMA_CH_FIFO_CTRL_RXSIZE(val)          ((val) & 0xf)
#define TEGRA186_ADMA_CH_FIFO_CTRL_OFLWTHRES(val)       (((val) & 0x1f) << 24)
#define TEGRA186_ADMA_CH_FIFO_CTRL_STRVTHRES(val)       (((val) & 0x1f) << 16)
#define TEGRA186_ADMA_CH_FIFO_CTRL_TXSIZE(val)          (((val) & 0x1f) << 8)
#define TEGRA186_ADMA_CH_FIFO_CTRL_RXSIZE(val)          ((val) & 0x1f)

#define ADMA_CH_LOWER_SRC_ADDR                          0x34
#define ADMA_CH_LOWER_TRG_ADDR                          0x3c
#define ADMA_CH_TC                                      0x44
#define ADMA_CH_TC_COUNT_MASK                           0x3ffffffc

#define ADMA_CH_XFER_STATUS                             0x54
#define ADMA_CH_XFER_STATUS_COUNT_MASK                  0xffff

#define ADMA_GLOBAL_CMD                                 0x00
#define ADMA_GLOBAL_SOFT_RESET                          0x04

#define TEGRA_ADMA_BURST_COMPLETE_TIME                  20

#define TEGRA210_FIFO_CTRL_DEFAULT (TEGRA210_ADMA_CH_FIFO_CTRL_OFLWTHRES(1) | \
                                    TEGRA210_ADMA_CH_FIFO_CTRL_STRVTHRES(1) | \
                                    TEGRA210_ADMA_CH_FIFO_CTRL_TXSIZE(3)    | \
                                    TEGRA210_ADMA_CH_FIFO_CTRL_RXSIZE(3))

#define TEGRA186_FIFO_CTRL_DEFAULT (TEGRA186_ADMA_CH_FIFO_CTRL_OFLWTHRES(1) | \
                                    TEGRA186_ADMA_CH_FIFO_CTRL_STRVTHRES(1) | \
                                    TEGRA186_ADMA_CH_FIFO_CTRL_TXSIZE(3)    | \
                                    TEGRA186_ADMA_CH_FIFO_CTRL_RXSIZE(3))

#define ADMA_CH_REG_FIELD_VAL(val, mask, shift) (((val) & mask) << shift)

struct tegra_adma;

/*
 * struct tegra_adma_chip_data - Tegra chip specific data
 * @global_reg_offset: Register offset of DMA global register.
 * @global_int_clear: Register offset of DMA global interrupt clear.
 * @ch_req_tx_shift: Register offset for AHUB transmit channel select.
 * @ch_req_rx_shift: Register offset for AHUB receive channel select.
 * @ch_base_offset: Register offset of DMA channel registers.
 * @ch_fifo_ctrl: Default value for channel FIFO CTRL register.
 * @ch_req_mask: Mask for Tx or Rx channel select.
 * @ch_req_max: Maximum number of Tx or Rx channels available.
 * @ch_reg_size: Size of DMA channel register space.
 * @nr_channels: Number of DMA channels available.
 */
struct tegra_adma_chip_data {
        unsigned int (*adma_get_burst_config)(unsigned int burst_size);
        unsigned int global_reg_offset;
        unsigned int global_int_clear;
        unsigned int ch_req_tx_shift;
        unsigned int ch_req_rx_shift;
        unsigned int ch_base_offset;
        unsigned int ch_fifo_ctrl;
        unsigned int ch_req_mask;
        unsigned int ch_req_max;
        unsigned int ch_reg_size;
        unsigned int nr_channels;
};

/*
 * struct tegra_adma_chan_regs - Tegra ADMA channel registers
 */
struct tegra_adma_chan_regs {
        unsigned int ctrl;
        unsigned int config;
        unsigned int src_addr;
        unsigned int trg_addr;
        unsigned int fifo_ctrl;
        unsigned int cmd;
        unsigned int tc;
};

/*
 * struct tegra_adma_desc - Tegra ADMA descriptor to manage transfer requests.
 */
struct tegra_adma_desc {
        struct virt_dma_desc            vd;
        struct tegra_adma_chan_regs     ch_regs;
        size_t                          buf_len;
        size_t                          period_len;
        size_t                          num_periods;
};

/*
 * struct tegra_adma_chan - Tegra ADMA channel information
 */
struct tegra_adma_chan {
        struct virt_dma_chan            vc;
        struct tegra_adma_desc          *desc;
        struct tegra_adma               *tdma;
        int                             irq;
        void __iomem                    *chan_addr;

        /* Slave channel configuration info */
        struct dma_slave_config         sconfig;
        enum dma_transfer_direction     sreq_dir;
        unsigned int                    sreq_index;
        bool                            sreq_reserved;
        struct tegra_adma_chan_regs     ch_regs;

        /* Transfer count and position info */
        unsigned int                    tx_buf_count;
        unsigned int                    tx_buf_pos;
};

/*
 * struct tegra_adma - Tegra ADMA controller information
 */
struct tegra_adma {
        struct dma_device               dma_dev;
        struct device                   *dev;
        void __iomem                    *base_addr;
        struct clk                      *ahub_clk;
        unsigned int                    nr_channels;
        unsigned long                   rx_requests_reserved;
        unsigned long                   tx_requests_reserved;

        /* Used to store global command register state when suspending */
        unsigned int                    global_cmd;

        const struct tegra_adma_chip_data *cdata;

        /* Last member of the structure */
        struct tegra_adma_chan          channels[0];
};

static inline void tdma_write(struct tegra_adma *tdma, u32 reg, u32 val)
{
        writel(val, tdma->base_addr + tdma->cdata->global_reg_offset + reg);
}

static inline u32 tdma_read(struct tegra_adma *tdma, u32 reg)
{
        return readl(tdma->base_addr + tdma->cdata->global_reg_offset + reg);
}

static inline void tdma_ch_write(struct tegra_adma_chan *tdc, u32 reg, u32 val)
{
        writel(val, tdc->chan_addr + reg);
}

static inline u32 tdma_ch_read(struct tegra_adma_chan *tdc, u32 reg)
{
        return readl(tdc->chan_addr + reg);
}

static inline struct tegra_adma_chan *to_tegra_adma_chan(struct dma_chan *dc)
{
        return container_of(dc, struct tegra_adma_chan, vc.chan);
}

static inline struct tegra_adma_desc *to_tegra_adma_desc(
                struct dma_async_tx_descriptor *td)
{
        return container_of(td, struct tegra_adma_desc, vd.tx);
}

static inline struct device *tdc2dev(struct tegra_adma_chan *tdc)
{
        return tdc->tdma->dev;
}

static void tegra_adma_desc_free(struct virt_dma_desc *vd)
{
        kfree(container_of(vd, struct tegra_adma_desc, vd));
}

static int tegra_adma_slave_config(struct dma_chan *dc,
                                   struct dma_slave_config *sconfig)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);

        memcpy(&tdc->sconfig, sconfig, sizeof(*sconfig));

        return 0;
}

static int tegra_adma_init(struct tegra_adma *tdma)
{
        u32 status;
        int ret;

        /* Clear any interrupts */
        tdma_write(tdma, tdma->cdata->global_int_clear, 0x1);

        /* Assert soft reset */
        tdma_write(tdma, ADMA_GLOBAL_SOFT_RESET, 0x1);

        /* Wait for reset to clear */
        ret = readx_poll_timeout(readl,
                                 tdma->base_addr +
                                 tdma->cdata->global_reg_offset +
                                 ADMA_GLOBAL_SOFT_RESET,
                                 status, status == 0, 20, 10000);
        if (ret)
                return ret;

        /* Enable global ADMA registers */
        tdma_write(tdma, ADMA_GLOBAL_CMD, 1);

        return 0;
}

static int tegra_adma_request_alloc(struct tegra_adma_chan *tdc,
                                    enum dma_transfer_direction direction)
{
        struct tegra_adma *tdma = tdc->tdma;
        unsigned int sreq_index = tdc->sreq_index;

        if (tdc->sreq_reserved)
                return tdc->sreq_dir == direction ? 0 : -EINVAL;

        if (sreq_index > tdma->cdata->ch_req_max) {
                dev_err(tdma->dev, "invalid DMA request\n");
                return -EINVAL;
        }

        switch (direction) {
        case DMA_MEM_TO_DEV:
                if (test_and_set_bit(sreq_index, &tdma->tx_requests_reserved)) {
                        dev_err(tdma->dev, "DMA request reserved\n");
                        return -EINVAL;
                }
                break;

        case DMA_DEV_TO_MEM:
                if (test_and_set_bit(sreq_index, &tdma->rx_requests_reserved)) {
                        dev_err(tdma->dev, "DMA request reserved\n");
                        return -EINVAL;
                }
                break;

        default:
                dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
                         dma_chan_name(&tdc->vc.chan));
                return -EINVAL;
        }

        tdc->sreq_dir = direction;
        tdc->sreq_reserved = true;

        return 0;
}

static void tegra_adma_request_free(struct tegra_adma_chan *tdc)
{
        struct tegra_adma *tdma = tdc->tdma;

        if (!tdc->sreq_reserved)
                return;

        switch (tdc->sreq_dir) {
        case DMA_MEM_TO_DEV:
                clear_bit(tdc->sreq_index, &tdma->tx_requests_reserved);
                break;

        case DMA_DEV_TO_MEM:
                clear_bit(tdc->sreq_index, &tdma->rx_requests_reserved);
                break;

        default:
                dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
                         dma_chan_name(&tdc->vc.chan));
                return;
        }

        tdc->sreq_reserved = false;
}

static u32 tegra_adma_irq_status(struct tegra_adma_chan *tdc)
{
        u32 status = tdma_ch_read(tdc, ADMA_CH_INT_STATUS);

        return status & ADMA_CH_INT_STATUS_XFER_DONE;
}

static u32 tegra_adma_irq_clear(struct tegra_adma_chan *tdc)
{
        u32 status = tegra_adma_irq_status(tdc);

        if (status)
                tdma_ch_write(tdc, ADMA_CH_INT_CLEAR, status);

        return status;
}

static void tegra_adma_stop(struct tegra_adma_chan *tdc)
{
        unsigned int status;

        /* Disable ADMA */
        tdma_ch_write(tdc, ADMA_CH_CMD, 0);

        /* Clear interrupt status */
        tegra_adma_irq_clear(tdc);

        if (readx_poll_timeout_atomic(readl, tdc->chan_addr + ADMA_CH_STATUS,
                        status, !(status & ADMA_CH_STATUS_XFER_EN),
                        20, 10000)) {
                dev_err(tdc2dev(tdc), "unable to stop DMA channel\n");
                return;
        }

        kfree(tdc->desc);
        tdc->desc = NULL;
}

static void tegra_adma_start(struct tegra_adma_chan *tdc)
{
        struct virt_dma_desc *vd = vchan_next_desc(&tdc->vc);
        struct tegra_adma_chan_regs *ch_regs;
        struct tegra_adma_desc *desc;

        if (!vd)
                return;

        list_del(&vd->node);

        desc = to_tegra_adma_desc(&vd->tx);

        if (!desc) {
                dev_warn(tdc2dev(tdc), "unable to start DMA, no descriptor\n");
                return;
        }

        ch_regs = &desc->ch_regs;

        tdc->tx_buf_pos = 0;
        tdc->tx_buf_count = 0;
        tdma_ch_write(tdc, ADMA_CH_TC, ch_regs->tc);
        tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);
        tdma_ch_write(tdc, ADMA_CH_LOWER_SRC_ADDR, ch_regs->src_addr);
        tdma_ch_write(tdc, ADMA_CH_LOWER_TRG_ADDR, ch_regs->trg_addr);
        tdma_ch_write(tdc, ADMA_CH_FIFO_CTRL, ch_regs->fifo_ctrl);
        tdma_ch_write(tdc, ADMA_CH_CONFIG, ch_regs->config);

        /* Start ADMA */
        tdma_ch_write(tdc, ADMA_CH_CMD, 1);

        tdc->desc = desc;
}

static unsigned int tegra_adma_get_residue(struct tegra_adma_chan *tdc)
{
        struct tegra_adma_desc *desc = tdc->desc;
        unsigned int max = ADMA_CH_XFER_STATUS_COUNT_MASK + 1;
        unsigned int pos = tdma_ch_read(tdc, ADMA_CH_XFER_STATUS);
        unsigned int periods_remaining;

        /*
         * Handle wrap around of buffer count register
         */
        if (pos < tdc->tx_buf_pos)
                tdc->tx_buf_count += pos + (max - tdc->tx_buf_pos);
        else
                tdc->tx_buf_count += pos - tdc->tx_buf_pos;

        periods_remaining = tdc->tx_buf_count % desc->num_periods;
        tdc->tx_buf_pos = pos;

        return desc->buf_len - (periods_remaining * desc->period_len);
}

static irqreturn_t tegra_adma_isr(int irq, void *dev_id)
{
        struct tegra_adma_chan *tdc = dev_id;
        unsigned long status;
        unsigned long flags;

        spin_lock_irqsave(&tdc->vc.lock, flags);

        status = tegra_adma_irq_clear(tdc);
        if (status == 0 || !tdc->desc) {
                spin_unlock_irqrestore(&tdc->vc.lock, flags);
                return IRQ_NONE;
        }

        vchan_cyclic_callback(&tdc->desc->vd);

        spin_unlock_irqrestore(&tdc->vc.lock, flags);

        return IRQ_HANDLED;
}

static void tegra_adma_issue_pending(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        unsigned long flags;

        spin_lock_irqsave(&tdc->vc.lock, flags);

        if (vchan_issue_pending(&tdc->vc)) {
                if (!tdc->desc)
                        tegra_adma_start(tdc);
        }

        spin_unlock_irqrestore(&tdc->vc.lock, flags);
}

static bool tegra_adma_is_paused(struct tegra_adma_chan *tdc)
{
        u32 csts;

        csts = tdma_ch_read(tdc, ADMA_CH_STATUS);
        csts &= ADMA_CH_STATUS_XFER_PAUSED;

        return csts ? true : false;
}

static int tegra_adma_pause(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        struct tegra_adma_desc *desc = tdc->desc;
        struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;
        int dcnt = 10;

        ch_regs->ctrl = tdma_ch_read(tdc, ADMA_CH_CTRL);
        ch_regs->ctrl |= (1 << ADMA_CH_CTRL_XFER_PAUSE_SHIFT);
        tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);

        while (dcnt-- && !tegra_adma_is_paused(tdc))
                udelay(TEGRA_ADMA_BURST_COMPLETE_TIME);

        if (dcnt < 0) {
                dev_err(tdc2dev(tdc), "unable to pause DMA channel\n");
                return -EBUSY;
        }

        return 0;
}

static int tegra_adma_resume(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        struct tegra_adma_desc *desc = tdc->desc;
        struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;

        ch_regs->ctrl = tdma_ch_read(tdc, ADMA_CH_CTRL);
        ch_regs->ctrl &= ~(1 << ADMA_CH_CTRL_XFER_PAUSE_SHIFT);
        tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);

        return 0;
}

static int tegra_adma_terminate_all(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        unsigned long flags;
        LIST_HEAD(head);

        spin_lock_irqsave(&tdc->vc.lock, flags);

        if (tdc->desc)
                tegra_adma_stop(tdc);

        tegra_adma_request_free(tdc);
        vchan_get_all_descriptors(&tdc->vc, &head);
        spin_unlock_irqrestore(&tdc->vc.lock, flags);
        vchan_dma_desc_free_list(&tdc->vc, &head);

        return 0;
}

static enum dma_status tegra_adma_tx_status(struct dma_chan *dc,
                                            dma_cookie_t cookie,
                                            struct dma_tx_state *txstate)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        struct tegra_adma_desc *desc;
        struct virt_dma_desc *vd;
        enum dma_status ret;
        unsigned long flags;
        unsigned int residual;

        ret = dma_cookie_status(dc, cookie, txstate);
        if (ret == DMA_COMPLETE || !txstate)
                return ret;

        spin_lock_irqsave(&tdc->vc.lock, flags);

        vd = vchan_find_desc(&tdc->vc, cookie);
        if (vd) {
                desc = to_tegra_adma_desc(&vd->tx);
                residual = desc->ch_regs.tc;
        } else if (tdc->desc && tdc->desc->vd.tx.cookie == cookie) {
                residual = tegra_adma_get_residue(tdc);
        } else {
                residual = 0;
        }

        spin_unlock_irqrestore(&tdc->vc.lock, flags);

        dma_set_residue(txstate, residual);

        return ret;
}

static unsigned int tegra210_adma_get_burst_config(unsigned int burst_size)
{
        if (!burst_size || burst_size > ADMA_CH_CONFIG_MAX_BURST_SIZE)
                burst_size = ADMA_CH_CONFIG_MAX_BURST_SIZE;

        return fls(burst_size) << ADMA_CH_CONFIG_BURST_SIZE_SHIFT;
}

static unsigned int tegra186_adma_get_burst_config(unsigned int burst_size)
{
        if (!burst_size || burst_size > ADMA_CH_CONFIG_MAX_BURST_SIZE)
                burst_size = ADMA_CH_CONFIG_MAX_BURST_SIZE;

        return (burst_size - 1) << ADMA_CH_CONFIG_BURST_SIZE_SHIFT;
}

static int tegra_adma_set_xfer_params(struct tegra_adma_chan *tdc,
                                      struct tegra_adma_desc *desc,
                                      dma_addr_t buf_addr,
                                      enum dma_transfer_direction direction)
{
        struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;
        const struct tegra_adma_chip_data *cdata = tdc->tdma->cdata;
        unsigned int burst_size, adma_dir;

        if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS)
                return -EINVAL;

        switch (direction) {
        case DMA_MEM_TO_DEV:
                adma_dir = ADMA_CH_CTRL_DIR_MEM2AHUB;
                burst_size = tdc->sconfig.dst_maxburst;
                ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(desc->num_periods - 1);
                ch_regs->ctrl = ADMA_CH_REG_FIELD_VAL(tdc->sreq_index,
                                                      cdata->ch_req_mask,
                                                      cdata->ch_req_tx_shift);
                ch_regs->src_addr = buf_addr;
                break;

        case DMA_DEV_TO_MEM:
                adma_dir = ADMA_CH_CTRL_DIR_AHUB2MEM;
                burst_size = tdc->sconfig.src_maxburst;
                ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(desc->num_periods - 1);
                ch_regs->ctrl = ADMA_CH_REG_FIELD_VAL(tdc->sreq_index,
                                                      cdata->ch_req_mask,
                                                      cdata->ch_req_rx_shift);
                ch_regs->trg_addr = buf_addr;
                break;

        default:
                dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
                return -EINVAL;
        }

        ch_regs->ctrl |= ADMA_CH_CTRL_DIR(adma_dir) |
                         ADMA_CH_CTRL_MODE_CONTINUOUS |
                         ADMA_CH_CTRL_FLOWCTRL_EN;
        ch_regs->config |= cdata->adma_get_burst_config(burst_size);
        ch_regs->config |= ADMA_CH_CONFIG_WEIGHT_FOR_WRR(1);
        ch_regs->fifo_ctrl = cdata->ch_fifo_ctrl;
        ch_regs->tc = desc->period_len & ADMA_CH_TC_COUNT_MASK;

        return tegra_adma_request_alloc(tdc, direction);
}

static struct dma_async_tx_descriptor *tegra_adma_prep_dma_cyclic(
        struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
        size_t period_len, enum dma_transfer_direction direction,
        unsigned long flags)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        struct tegra_adma_desc *desc = NULL;

        if (!buf_len || !period_len || period_len > ADMA_CH_TC_COUNT_MASK) {
                dev_err(tdc2dev(tdc), "invalid buffer/period len\n");
                return NULL;
        }

        if (buf_len % period_len) {
                dev_err(tdc2dev(tdc), "buf_len not a multiple of period_len\n");
                return NULL;
        }

        if (!IS_ALIGNED(buf_addr, 4)) {
                dev_err(tdc2dev(tdc), "invalid buffer alignment\n");
                return NULL;
        }

        desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
        if (!desc)
                return NULL;

        desc->buf_len = buf_len;
        desc->period_len = period_len;
        desc->num_periods = buf_len / period_len;

        if (tegra_adma_set_xfer_params(tdc, desc, buf_addr, direction)) {
                kfree(desc);
                return NULL;
        }

        return vchan_tx_prep(&tdc->vc, &desc->vd, flags);
}

static int tegra_adma_alloc_chan_resources(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
        int ret;

        ret = request_irq(tdc->irq, tegra_adma_isr, 0, dma_chan_name(dc), tdc);
        if (ret) {
                dev_err(tdc2dev(tdc), "failed to get interrupt for %s\n",
                        dma_chan_name(dc));
                return ret;
        }

        ret = pm_runtime_get_sync(tdc2dev(tdc));
        if (ret < 0) {
                free_irq(tdc->irq, tdc);
                return ret;
        }

        dma_cookie_init(&tdc->vc.chan);

        return 0;
}

static void tegra_adma_free_chan_resources(struct dma_chan *dc)
{
        struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);

        tegra_adma_terminate_all(dc);
        vchan_free_chan_resources(&tdc->vc);
        tasklet_kill(&tdc->vc.task);
        free_irq(tdc->irq, tdc);
        pm_runtime_put(tdc2dev(tdc));

        tdc->sreq_index = 0;
        tdc->sreq_dir = DMA_TRANS_NONE;
}

static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
                                           struct of_dma *ofdma)
{
        struct tegra_adma *tdma = ofdma->of_dma_data;
        struct tegra_adma_chan *tdc;
        struct dma_chan *chan;
        unsigned int sreq_index;

        if (dma_spec->args_count != 1)
                return NULL;

        sreq_index = dma_spec->args[0];

        if (sreq_index == 0) {
                dev_err(tdma->dev, "DMA request must not be 0\n");
                return NULL;
        }

        chan = dma_get_any_slave_channel(&tdma->dma_dev);
        if (!chan)
                return NULL;

        tdc = to_tegra_adma_chan(chan);
        tdc->sreq_index = sreq_index;

        return chan;
}

static int __maybe_unused tegra_adma_runtime_suspend(struct device *dev)
{
        struct tegra_adma *tdma = dev_get_drvdata(dev);
        struct tegra_adma_chan_regs *ch_reg;
        struct tegra_adma_chan *tdc;
        int i;

        tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
        if (!tdma->global_cmd)
                goto clk_disable;

        for (i = 0; i < tdma->nr_channels; i++) {
                tdc = &tdma->channels[i];
                ch_reg = &tdc->ch_regs;
                ch_reg->cmd = tdma_ch_read(tdc, ADMA_CH_CMD);
                /* skip if channel is not active */
                if (!ch_reg->cmd)
                        continue;
                ch_reg->tc = tdma_ch_read(tdc, ADMA_CH_TC);
                ch_reg->src_addr = tdma_ch_read(tdc, ADMA_CH_LOWER_SRC_ADDR);
                ch_reg->trg_addr = tdma_ch_read(tdc, ADMA_CH_LOWER_TRG_ADDR);
                ch_reg->ctrl = tdma_ch_read(tdc, ADMA_CH_CTRL);
                ch_reg->fifo_ctrl = tdma_ch_read(tdc, ADMA_CH_FIFO_CTRL);
                ch_reg->config = tdma_ch_read(tdc, ADMA_CH_CONFIG);
        }

clk_disable:
        clk_disable_unprepare(tdma->ahub_clk);

        return 0;
}

static int __maybe_unused tegra_adma_runtime_resume(struct device *dev)
{
        struct tegra_adma *tdma = dev_get_drvdata(dev);
        struct tegra_adma_chan_regs *ch_reg;
        struct tegra_adma_chan *tdc;
        int ret, i;

        ret = clk_prepare_enable(tdma->ahub_clk);
        if (ret) {
                dev_err(dev, "ahub clk_enable failed: %d\n", ret);
                return ret;
        }
        tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);

        if (!tdma->global_cmd)
                return 0;

        for (i = 0; i < tdma->nr_channels; i++) {
                tdc = &tdma->channels[i];
                ch_reg = &tdc->ch_regs;
                /* skip if channel was not active earlier */
                if (!ch_reg->cmd)
                        continue;
                tdma_ch_write(tdc, ADMA_CH_TC, ch_reg->tc);
                tdma_ch_write(tdc, ADMA_CH_LOWER_SRC_ADDR, ch_reg->src_addr);
                tdma_ch_write(tdc, ADMA_CH_LOWER_TRG_ADDR, ch_reg->trg_addr);
                tdma_ch_write(tdc, ADMA_CH_CTRL, ch_reg->ctrl);
                tdma_ch_write(tdc, ADMA_CH_FIFO_CTRL, ch_reg->fifo_ctrl);
                tdma_ch_write(tdc, ADMA_CH_CONFIG, ch_reg->config);
                tdma_ch_write(tdc, ADMA_CH_CMD, ch_reg->cmd);
        }

        return 0;
}

static const struct tegra_adma_chip_data tegra210_chip_data = {
        .adma_get_burst_config  = tegra210_adma_get_burst_config,
        .global_reg_offset      = 0xc00,
        .global_int_clear       = 0x20,
        .ch_req_tx_shift        = 28,
        .ch_req_rx_shift        = 24,
        .ch_base_offset         = 0,
        .ch_fifo_ctrl           = TEGRA210_FIFO_CTRL_DEFAULT,
        .ch_req_mask            = 0xf,
        .ch_req_max             = 10,
        .ch_reg_size            = 0x80,
        .nr_channels            = 22,
};

static const struct tegra_adma_chip_data tegra186_chip_data = {
        .adma_get_burst_config  = tegra186_adma_get_burst_config,
        .global_reg_offset      = 0,
        .global_int_clear       = 0x402c,
        .ch_req_tx_shift        = 27,
        .ch_req_rx_shift        = 22,
        .ch_base_offset         = 0x10000,
        .ch_fifo_ctrl           = TEGRA186_FIFO_CTRL_DEFAULT,
        .ch_req_mask            = 0x1f,
        .ch_req_max             = 20,
        .ch_reg_size            = 0x100,
        .nr_channels            = 32,
};

static const struct of_device_id tegra_adma_of_match[] = {
        { .compatible = "nvidia,tegra210-adma", .data = &tegra210_chip_data },
        { .compatible = "nvidia,tegra186-adma", .data = &tegra186_chip_data },
        { },
};
MODULE_DEVICE_TABLE(of, tegra_adma_of_match);

static int tegra_adma_probe(struct platform_device *pdev)
{
        const struct tegra_adma_chip_data *cdata;
        struct tegra_adma *tdma;
        struct resource *res;
        int ret, i;

        cdata = of_device_get_match_data(&pdev->dev);
        if (!cdata) {
                dev_err(&pdev->dev, "device match data not found\n");
                return -ENODEV;
        }

        tdma = devm_kzalloc(&pdev->dev,
                            struct_size(tdma, channels, cdata->nr_channels),
                            GFP_KERNEL);
        if (!tdma)
                return -ENOMEM;

        tdma->dev = &pdev->dev;
        tdma->cdata = cdata;
        tdma->nr_channels = cdata->nr_channels;
        platform_set_drvdata(pdev, tdma);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(tdma->base_addr))
                return PTR_ERR(tdma->base_addr);

        tdma->ahub_clk = devm_clk_get(&pdev->dev, "d_audio");
        if (IS_ERR(tdma->ahub_clk)) {
                dev_err(&pdev->dev, "Error: Missing ahub controller clock\n");
                return PTR_ERR(tdma->ahub_clk);
        }

        INIT_LIST_HEAD(&tdma->dma_dev.channels);
        for (i = 0; i < tdma->nr_channels; i++) {
                struct tegra_adma_chan *tdc = &tdma->channels[i];

                tdc->chan_addr = tdma->base_addr + cdata->ch_base_offset
                                 + (cdata->ch_reg_size * i);

                tdc->irq = of_irq_get(pdev->dev.of_node, i);
                if (tdc->irq <= 0) {
                        ret = tdc->irq ?: -ENXIO;
                        goto irq_dispose;
                }

                vchan_init(&tdc->vc, &tdma->dma_dev);
                tdc->vc.desc_free = tegra_adma_desc_free;
                tdc->tdma = tdma;
        }

        pm_runtime_enable(&pdev->dev);

        ret = pm_runtime_get_sync(&pdev->dev);
        if (ret < 0)
                goto rpm_disable;

        ret = tegra_adma_init(tdma);
        if (ret)
                goto rpm_put;

        dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
        dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
        dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);

        tdma->dma_dev.dev = &pdev->dev;
        tdma->dma_dev.device_alloc_chan_resources =
                                        tegra_adma_alloc_chan_resources;
        tdma->dma_dev.device_free_chan_resources =
                                        tegra_adma_free_chan_resources;
        tdma->dma_dev.device_issue_pending = tegra_adma_issue_pending;
        tdma->dma_dev.device_prep_dma_cyclic = tegra_adma_prep_dma_cyclic;
        tdma->dma_dev.device_config = tegra_adma_slave_config;
        tdma->dma_dev.device_tx_status = tegra_adma_tx_status;
        tdma->dma_dev.device_terminate_all = tegra_adma_terminate_all;
        tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
        tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
        tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
        tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
        tdma->dma_dev.device_pause = tegra_adma_pause;
        tdma->dma_dev.device_resume = tegra_adma_resume;

        ret = dma_async_device_register(&tdma->dma_dev);
        if (ret < 0) {
                dev_err(&pdev->dev, "ADMA registration failed: %d\n", ret);
                goto irq_dispose;
        }

        ret = of_dma_controller_register(pdev->dev.of_node,
                                         tegra_dma_of_xlate, tdma);
        if (ret < 0) {
                dev_err(&pdev->dev, "ADMA OF registration failed %d\n", ret);
                goto dma_remove;
        }

        pm_runtime_put(&pdev->dev);

        dev_info(&pdev->dev, "Tegra210 ADMA driver registered %d channels\n",
                 tdma->nr_channels);

        return 0;

dma_remove:
        dma_async_device_unregister(&tdma->dma_dev);
rpm_put:
        pm_runtime_put_sync(&pdev->dev);
rpm_disable:
        pm_runtime_disable(&pdev->dev);
irq_dispose:
        while (--i >= 0)
                irq_dispose_mapping(tdma->channels[i].irq);

        return ret;
}

static int tegra_adma_remove(struct platform_device *pdev)
{
        struct tegra_adma *tdma = platform_get_drvdata(pdev);
        int i;

        of_dma_controller_free(pdev->dev.of_node);
        dma_async_device_unregister(&tdma->dma_dev);

        for (i = 0; i < tdma->nr_channels; ++i)
                irq_dispose_mapping(tdma->channels[i].irq);

        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

        return 0;
}

static const struct dev_pm_ops tegra_adma_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(tegra_adma_runtime_suspend,
                           tegra_adma_runtime_resume, NULL)
        SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
                                     pm_runtime_force_resume)
};

static struct platform_driver tegra_admac_driver = {
        .driver = {
                .name   = "tegra-adma",
                .pm     = &tegra_adma_dev_pm_ops,
                .of_match_table = tegra_adma_of_match,
        },
        .probe          = tegra_adma_probe,
        .remove         = tegra_adma_remove,
};

module_platform_driver(tegra_admac_driver);

MODULE_ALIAS("platform:tegra210-adma");
MODULE_DESCRIPTION("NVIDIA Tegra ADMA driver");
MODULE_AUTHOR("Dara Ramesh <dramesh@nvidia.com>");
MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
MODULE_LICENSE("GPL v2");