Quelle  fsl-edma-main.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * drivers/dma/fsl-edma.c
 *
 * Copyright 2013-2014 Freescale Semiconductor, Inc.
 * Copyright 2024 NXP
 *
 * Driver for the Freescale eDMA engine with flexible channel multiplexing
 * capability for DMA request sources. The eDMA block can be found on some
 * Vybrid, Layerscape and S32G SoCs.
 */

#include <dt-bindings/dma/fsl-edma.h>
#include <linux/bitfield.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/property.h>

#include "fsl-edma-common.h"

static void fsl_edma_synchronize(struct dma_chan *chan)
{
 struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);

 vchan_synchronize(&fsl_chan->vchan);
}

static irqreturn_t fsl_edma_tx_handler(int irq, void *dev_id)
{
 struct fsl_edma_engine *fsl_edma = dev_id;
 unsigned int intr, ch;
 struct edma_regs *regs = &fsl_edma->regs;

 intr = edma_readl(fsl_edma, regs->intl);
 if (!intr)
  return IRQ_NONE;

 for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  if (intr & (0x1 << ch)) {
   edma_writeb(fsl_edma, EDMA_CINT_CINT(ch), regs->cint);
   fsl_edma_tx_chan_handler(&fsl_edma->chans[ch]);
  }
 }
 return IRQ_HANDLED;
}

static void fsl_edma3_err_check(struct fsl_edma_chan *fsl_chan)
{
 unsigned int ch_err;
 u32 val;

 scoped_guard(spinlock, &fsl_chan->vchan.lock) {
  ch_err = edma_readl_chreg(fsl_chan, ch_es);
  if (!(ch_err & EDMA_V3_CH_ERR))
   return;

  edma_writel_chreg(fsl_chan, EDMA_V3_CH_ERR, ch_es);
  val = edma_readl_chreg(fsl_chan, ch_csr);
  val &= ~EDMA_V3_CH_CSR_ERQ;
  edma_writel_chreg(fsl_chan, val, ch_csr);
 }

 /* Ignore this interrupt since channel has been disabled already */
 if (!fsl_chan->edesc)
  return;

 if (ch_err & EDMA_V3_CH_ERR_DBE)
  dev_err(&fsl_chan->pdev->dev, "Destination Bus Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_SBE)
  dev_err(&fsl_chan->pdev->dev, "Source Bus Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_SGE)
  dev_err(&fsl_chan->pdev->dev, "Scatter/Gather Configuration Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_NCE)
  dev_err(&fsl_chan->pdev->dev, "NBYTES/CITER Configuration Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_DOE)
  dev_err(&fsl_chan->pdev->dev, "Destination Offset Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_DAE)
  dev_err(&fsl_chan->pdev->dev, "Destination Address Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_SOE)
  dev_err(&fsl_chan->pdev->dev, "Source Offset Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_SAE)
  dev_err(&fsl_chan->pdev->dev, "Source Address Error interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_ECX)
  dev_err(&fsl_chan->pdev->dev, "Transfer Canceled interrupt.\n");

 if (ch_err & EDMA_V3_CH_ERR_UCE)
  dev_err(&fsl_chan->pdev->dev, "Uncorrectable TCD error during channel execution interrupt.\n");

 fsl_chan->status = DMA_ERROR;
}

static irqreturn_t fsl_edma3_err_handler_per_chan(int irq, void *dev_id)
{
 struct fsl_edma_chan *fsl_chan = dev_id;

 fsl_edma3_err_check(fsl_chan);

 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma3_err_handler_shared(int irq, void *dev_id)
{
 struct fsl_edma_engine *fsl_edma = dev_id;
 unsigned int ch;

 for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  if (fsl_edma->chan_masked & BIT(ch))
   continue;

  fsl_edma3_err_check(&fsl_edma->chans[ch]);
 }

 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma3_tx_handler(int irq, void *dev_id)
{
 struct fsl_edma_chan *fsl_chan = dev_id;
 unsigned int intr;

 intr = edma_readl_chreg(fsl_chan, ch_int);
 if (!intr)
  return IRQ_NONE;

 edma_writel_chreg(fsl_chan, 1, ch_int);

 fsl_edma_tx_chan_handler(fsl_chan);

 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma2_tx_handler(int irq, void *devi_id)
{
 struct fsl_edma_chan *fsl_chan = devi_id;

 return fsl_edma_tx_handler(irq, fsl_chan->edma);
}

static irqreturn_t fsl_edma3_or_tx_handler(int irq, void *dev_id,
        u8 start, u8 end)
{
 struct fsl_edma_engine *fsl_edma = dev_id;
 struct fsl_edma_chan *chan;
 int i;

 end = min(end, fsl_edma->n_chans);

 for (i = start; i < end; i++) {
  chan = &fsl_edma->chans[i];

  fsl_edma3_tx_handler(irq, chan);
 }

 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma3_tx_0_15_handler(int irq, void *dev_id)
{
 return fsl_edma3_or_tx_handler(irq, dev_id, 0, 16);
}

static irqreturn_t fsl_edma3_tx_16_31_handler(int irq, void *dev_id)
{
 return fsl_edma3_or_tx_handler(irq, dev_id, 16, 32);
}

static irqreturn_t fsl_edma3_or_err_handler(int irq, void *dev_id)
{
 struct fsl_edma_engine *fsl_edma = dev_id;
 struct edma_regs *regs = &fsl_edma->regs;
 unsigned int err, ch, ch_es;
 struct fsl_edma_chan *chan;

 err = edma_readl(fsl_edma, regs->es);
 if (!(err & EDMA_V3_MP_ES_VLD))
  return IRQ_NONE;

 for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  chan = &fsl_edma->chans[ch];

  ch_es = edma_readl_chreg(chan, ch_es);
  if (!(ch_es & EDMA_V3_CH_ES_ERR))
   continue;

  edma_writel_chreg(chan, EDMA_V3_CH_ES_ERR, ch_es);
  fsl_edma_disable_request(chan);
  fsl_edma->chans[ch].status = DMA_ERROR;
 }

 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
{
 struct fsl_edma_engine *fsl_edma = dev_id;
 unsigned int err, ch;
 struct edma_regs *regs = &fsl_edma->regs;

 err = edma_readl(fsl_edma, regs->errl);
 if (!err)
  return IRQ_NONE;

 for (ch = 0; ch < fsl_edma->n_chans; ch++) {
  if (err & (0x1 << ch)) {
   fsl_edma_disable_request(&fsl_edma->chans[ch]);
   edma_writeb(fsl_edma, EDMA_CERR_CERR(ch), regs->cerr);
   fsl_edma_err_chan_handler(&fsl_edma->chans[ch]);
  }
 }
 return IRQ_HANDLED;
}

static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
{
 if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
  return IRQ_HANDLED;

 return fsl_edma_err_handler(irq, dev_id);
}

static bool fsl_edma_srcid_in_use(struct fsl_edma_engine *fsl_edma, u32 srcid)
{
 struct fsl_edma_chan *fsl_chan;
 int i;

 for (i = 0; i < fsl_edma->n_chans; i++) {
  fsl_chan = &fsl_edma->chans[i];

  if (fsl_chan->srcid && srcid == fsl_chan->srcid) {
   dev_err(&fsl_chan->pdev->dev, "The srcid is in use, can't use!\n");
   return true;
  }
 }
 return false;
}

static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
  struct of_dma *ofdma)
{
 struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
 struct dma_chan *chan, *_chan;
 struct fsl_edma_chan *fsl_chan;
 u32 dmamux_nr = fsl_edma->drvdata->dmamuxs;
 unsigned long chans_per_mux = fsl_edma->n_chans / dmamux_nr;

 if (dma_spec->args_count != 2)
  return NULL;

 guard(mutex)(&fsl_edma->fsl_edma_mutex);

 list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels, device_node) {
  if (chan->client_count)
   continue;

  if (fsl_edma_srcid_in_use(fsl_edma, dma_spec->args[1]))
   return NULL;

  if ((chan->chan_id / chans_per_mux) == dma_spec->args[0]) {
   chan = dma_get_slave_channel(chan);
   if (chan) {
    chan->device->privatecnt++;
    fsl_chan = to_fsl_edma_chan(chan);
    fsl_chan->srcid = dma_spec->args[1];

    if (!fsl_chan->srcid) {
     dev_err(&fsl_chan->pdev->dev, "Invalidate srcid %d\n",
      fsl_chan->srcid);
     return NULL;
    }

    fsl_edma_chan_mux(fsl_chan, fsl_chan->srcid,
      true);
    return chan;
   }
  }
 }
 return NULL;
}

static struct dma_chan *fsl_edma3_xlate(struct of_phandle_args *dma_spec,
     struct of_dma *ofdma)
{
 struct fsl_edma_engine *fsl_edma = ofdma->of_dma_data;
 struct dma_chan *chan, *_chan;
 struct fsl_edma_chan *fsl_chan;
 bool b_chmux;
 int i;

 if (dma_spec->args_count != 3)
  return NULL;

 b_chmux = !!(fsl_edma->drvdata->flags & FSL_EDMA_DRV_HAS_CHMUX);

 guard(mutex)(&fsl_edma->fsl_edma_mutex);
 list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels,
     device_node) {

  if (chan->client_count)
   continue;

  fsl_chan = to_fsl_edma_chan(chan);
  if (fsl_edma_srcid_in_use(fsl_edma, dma_spec->args[0]))
   return NULL;
  i = fsl_chan - fsl_edma->chans;

  fsl_chan->priority = dma_spec->args[1];
  fsl_chan->is_rxchan = dma_spec->args[2] & FSL_EDMA_RX;
  fsl_chan->is_remote = dma_spec->args[2] & FSL_EDMA_REMOTE;
  fsl_chan->is_multi_fifo = dma_spec->args[2] & FSL_EDMA_MULTI_FIFO;

  if ((dma_spec->args[2] & FSL_EDMA_EVEN_CH) && (i & 0x1))
   continue;

  if ((dma_spec->args[2] & FSL_EDMA_ODD_CH) && !(i & 0x1))
   continue;

  if (!b_chmux && i == dma_spec->args[0]) {
   chan = dma_get_slave_channel(chan);
   chan->device->privatecnt++;
   return chan;
  } else if (b_chmux && !fsl_chan->srcid) {
   /* if controller support channel mux, choose a free channel */
   chan = dma_get_slave_channel(chan);
   chan->device->privatecnt++;
   fsl_chan->srcid = dma_spec->args[0];
   return chan;
  }
 }
 return NULL;
}

static int
fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
 int ret;

 edma_writel(fsl_edma, ~0, fsl_edma->regs.intl);

 fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
 if (fsl_edma->txirq < 0)
  return fsl_edma->txirq;

 fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
 if (fsl_edma->errirq < 0)
  return fsl_edma->errirq;

 if (fsl_edma->txirq == fsl_edma->errirq) {
  ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
    fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
  if (ret) {
   dev_err(&pdev->dev, "Can't register eDMA IRQ.\n");
   return ret;
  }
 } else {
  ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
    fsl_edma_tx_handler, 0, "eDMA tx", fsl_edma);
  if (ret) {
   dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
   return ret;
  }

  ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
    fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
  if (ret) {
   dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
   return ret;
  }
 }

 return 0;
}

static int fsl_edma3_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
 char *errirq_name;
 int i, ret;

 for (i = 0; i < fsl_edma->n_chans; i++) {

  struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];

  if (fsl_edma->chan_masked & BIT(i))
   continue;

  /* request channel irq */
  fsl_chan->txirq = platform_get_irq(pdev, i);
  if (fsl_chan->txirq < 0)
   return  -EINVAL;

  fsl_chan->irq_handler = fsl_edma3_tx_handler;

  if (!(fsl_edma->drvdata->flags & FSL_EDMA_DRV_ERRIRQ_SHARE)) {
   fsl_chan->errirq = fsl_chan->txirq;
   fsl_chan->errirq_handler = fsl_edma3_err_handler_per_chan;
  }
 }

 /* All channel err use one irq number */
 if (fsl_edma->drvdata->flags & FSL_EDMA_DRV_ERRIRQ_SHARE) {
  /* last one is error irq */
  fsl_edma->errirq = platform_get_irq_optional(pdev, fsl_edma->n_chans);
  if (fsl_edma->errirq < 0)
   return 0; /* dts miss err irq, treat as no err irq case */

  errirq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s-err",
          dev_name(&pdev->dev));

  ret = devm_request_irq(&pdev->dev, fsl_edma->errirq, fsl_edma3_err_handler_shared,
           0, errirq_name, fsl_edma);
  if (ret)
   return dev_err_probe(&pdev->dev, ret, "Can't register eDMA err IRQ.\n");
 }

 return 0;
}

static int fsl_edma3_or_irq_init(struct platform_device *pdev,
     struct fsl_edma_engine *fsl_edma)
{
 int ret;

 fsl_edma->txirq = platform_get_irq_byname(pdev, "tx-0-15");
 if (fsl_edma->txirq < 0)
  return fsl_edma->txirq;

 fsl_edma->txirq_16_31 = platform_get_irq_byname(pdev, "tx-16-31");
 if (fsl_edma->txirq_16_31 < 0)
  return fsl_edma->txirq_16_31;

 fsl_edma->errirq = platform_get_irq_byname(pdev, "err");
 if (fsl_edma->errirq < 0)
  return fsl_edma->errirq;

 ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
          fsl_edma3_tx_0_15_handler, 0, "eDMA tx0_15",
          fsl_edma);
 if (ret)
  return dev_err_probe(&pdev->dev, ret,
          "Can't register eDMA tx0_15 IRQ.\n");

 if (fsl_edma->n_chans > 16) {
  ret = devm_request_irq(&pdev->dev, fsl_edma->txirq_16_31,
           fsl_edma3_tx_16_31_handler, 0,
           "eDMA tx16_31", fsl_edma);
  if (ret)
   return dev_err_probe(&pdev->dev, ret,
     "Can't register eDMA tx16_31 IRQ.\n");
 }

 ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
          fsl_edma3_or_err_handler, 0, "eDMA err",
          fsl_edma);
 if (ret)
  return dev_err_probe(&pdev->dev, ret,
         "Can't register eDMA err IRQ.\n");

 return 0;
}

static int
fsl_edma2_irq_init(struct platform_device *pdev,
     struct fsl_edma_engine *fsl_edma)
{
 int i, ret, irq;
 int count;

 edma_writel(fsl_edma, ~0, fsl_edma->regs.intl);

 count = platform_irq_count(pdev);
 dev_dbg(&pdev->dev, "%s Found %d interrupts\r\n", __func__, count);
 if (count <= 2) {
  dev_err(&pdev->dev, "Interrupts in DTS not correct.\n");
  return -EINVAL;
 }
 /*
 * 16 channel independent interrupts + 1 error interrupt on i.mx7ulp.
 * 2 channel share one interrupt, for example, ch0/ch16, ch1/ch17...
 * For now, just simply request irq without IRQF_SHARED flag, since 16
 * channels are enough on i.mx7ulp whose M4 domain own some peripherals.
 */
 for (i = 0; i < count; i++) {
  irq = platform_get_irq(pdev, i);
  ret = 0;
  if (irq < 0)
   return -ENXIO;

  /* The last IRQ is for eDMA err */
  if (i == count - 1) {
   fsl_edma->errirq = irq;
   ret = devm_request_irq(&pdev->dev, irq,
      fsl_edma_err_handler,
      0, "eDMA2-ERR", fsl_edma);
  } else {
   fsl_edma->chans[i].txirq = irq;
   fsl_edma->chans[i].irq_handler = fsl_edma2_tx_handler;
  }

  if (ret)
   return ret;
 }

 return 0;
}

static void fsl_edma_irq_exit(
  struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
 if (fsl_edma->txirq == fsl_edma->errirq) {
  if (fsl_edma->txirq >= 0)
   devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
 } else {
  if (fsl_edma->txirq >= 0)
   devm_free_irq(&pdev->dev, fsl_edma->txirq, fsl_edma);
  if (fsl_edma->errirq >= 0)
   devm_free_irq(&pdev->dev, fsl_edma->errirq, fsl_edma);
 }
}

static void fsl_disable_clocks(struct fsl_edma_engine *fsl_edma, int nr_clocks)
{
 int i;

 for (i = 0; i < nr_clocks; i++)
  clk_disable_unprepare(fsl_edma->muxclk[i]);
}

static struct fsl_edma_drvdata vf610_data = {
 .dmamuxs = DMAMUX_NR,
 .flags = FSL_EDMA_DRV_WRAP_IO,
 .chreg_off = EDMA_TCD,
 .chreg_space_sz = sizeof(struct fsl_edma_hw_tcd),
 .setup_irq = fsl_edma_irq_init,
};

static struct fsl_edma_drvdata ls1028a_data = {
 .dmamuxs = DMAMUX_NR,
 .flags = FSL_EDMA_DRV_MUX_SWAP | FSL_EDMA_DRV_WRAP_IO,
 .chreg_off = EDMA_TCD,
 .chreg_space_sz = sizeof(struct fsl_edma_hw_tcd),
 .setup_irq = fsl_edma_irq_init,
};

static struct fsl_edma_drvdata imx7ulp_data = {
 .dmamuxs = 1,
 .chreg_off = EDMA_TCD,
 .chreg_space_sz = sizeof(struct fsl_edma_hw_tcd),
 .flags = FSL_EDMA_DRV_HAS_DMACLK | FSL_EDMA_DRV_CONFIG32,
 .setup_irq = fsl_edma2_irq_init,
};

static struct fsl_edma_drvdata imx8qm_data = {
 .flags = FSL_EDMA_DRV_HAS_PD | FSL_EDMA_DRV_EDMA3 | FSL_EDMA_DRV_MEM_REMOTE
   | FSL_EDMA_DRV_ERRIRQ_SHARE,
 .chreg_space_sz = 0x10000,
 .chreg_off = 0x10000,
 .setup_irq = fsl_edma3_irq_init,
};

static struct fsl_edma_drvdata imx8ulp_data = {
 .flags = FSL_EDMA_DRV_HAS_CHMUX | FSL_EDMA_DRV_HAS_CHCLK | FSL_EDMA_DRV_HAS_DMACLK |
   FSL_EDMA_DRV_EDMA3,
 .chreg_space_sz = 0x10000,
 .chreg_off = 0x10000,
 .mux_off = 0x10000 + offsetof(struct fsl_edma3_ch_reg, ch_mux),
 .mux_skip = 0x10000,
 .setup_irq = fsl_edma3_irq_init,
};

static struct fsl_edma_drvdata imx93_data3 = {
 .flags = FSL_EDMA_DRV_HAS_DMACLK | FSL_EDMA_DRV_EDMA3 | FSL_EDMA_DRV_ERRIRQ_SHARE,
 .chreg_space_sz = 0x10000,
 .chreg_off = 0x10000,
 .setup_irq = fsl_edma3_irq_init,
};

static struct fsl_edma_drvdata imx93_data4 = {
 .flags = FSL_EDMA_DRV_HAS_CHMUX | FSL_EDMA_DRV_HAS_DMACLK | FSL_EDMA_DRV_EDMA4
   | FSL_EDMA_DRV_ERRIRQ_SHARE,
 .chreg_space_sz = 0x8000,
 .chreg_off = 0x10000,
 .mux_off = 0x10000 + offsetof(struct fsl_edma3_ch_reg, ch_mux),
 .mux_skip = 0x8000,
 .setup_irq = fsl_edma3_irq_init,
};

static struct fsl_edma_drvdata imx95_data5 = {
 .flags = FSL_EDMA_DRV_HAS_CHMUX | FSL_EDMA_DRV_HAS_DMACLK | FSL_EDMA_DRV_EDMA4 |
   FSL_EDMA_DRV_TCD64 | FSL_EDMA_DRV_ERRIRQ_SHARE,
 .chreg_space_sz = 0x8000,
 .chreg_off = 0x10000,
 .mux_off = 0x200,
 .mux_skip = sizeof(u32),
 .setup_irq = fsl_edma3_irq_init,
};

static const struct fsl_edma_drvdata s32g2_data = {
 .dmamuxs = DMAMUX_NR,
 .chreg_space_sz = EDMA_TCD,
 .chreg_off = 0x4000,
 .flags = FSL_EDMA_DRV_EDMA3 | FSL_EDMA_DRV_MUX_SWAP,
 .setup_irq = fsl_edma3_or_irq_init,
};

static const struct of_device_id fsl_edma_dt_ids[] = {
 { .compatible = "fsl,vf610-edma", .data = &vf610_data},
 { .compatible = "fsl,ls1028a-edma", .data = &ls1028a_data},
 { .compatible = "fsl,imx7ulp-edma", .data = &imx7ulp_data},
 { .compatible = "fsl,imx8qm-edma", .data = &imx8qm_data},
 { .compatible = "fsl,imx8ulp-edma", .data = &imx8ulp_data},
 { .compatible = "fsl,imx93-edma3", .data = &imx93_data3},
 { .compatible = "fsl,imx93-edma4", .data = &imx93_data4},
 { .compatible = "fsl,imx95-edma5", .data = &imx95_data5},
 { .compatible = "nxp,s32g2-edma", .data = &s32g2_data},
 { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);

static void fsl_edma3_detach_pd(struct fsl_edma_engine *fsl_edma)
{
 struct fsl_edma_chan *fsl_chan;
 int i;

 for (i = 0; i < fsl_edma->n_chans; i++) {
  if (fsl_edma->chan_masked & BIT(i))
   continue;
  fsl_chan = &fsl_edma->chans[i];
  if (fsl_chan->pd_dev_link)
   device_link_del(fsl_chan->pd_dev_link);
  if (fsl_chan->pd_dev) {
   dev_pm_domain_detach(fsl_chan->pd_dev, false);
   pm_runtime_dont_use_autosuspend(fsl_chan->pd_dev);
   pm_runtime_set_suspended(fsl_chan->pd_dev);
  }
 }
}

static void devm_fsl_edma3_detach_pd(void *data)
{
 fsl_edma3_detach_pd(data);
}

static int fsl_edma3_attach_pd(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
{
 struct fsl_edma_chan *fsl_chan;
 struct device *pd_chan;
 struct device *dev;
 int i;

 dev = &pdev->dev;

 for (i = 0; i < fsl_edma->n_chans; i++) {
  if (fsl_edma->chan_masked & BIT(i))
   continue;

  fsl_chan = &fsl_edma->chans[i];

  pd_chan = dev_pm_domain_attach_by_id(dev, i);
  if (IS_ERR_OR_NULL(pd_chan)) {
   dev_err(dev, "Failed attach pd %d\n", i);
   goto detach;
  }

  fsl_chan->pd_dev_link = device_link_add(dev, pd_chan, DL_FLAG_STATELESS |
          DL_FLAG_PM_RUNTIME |
          DL_FLAG_RPM_ACTIVE);
  if (!fsl_chan->pd_dev_link) {
   dev_err(dev, "Failed to add device_link to %d\n", i);
   dev_pm_domain_detach(pd_chan, false);
   goto detach;
  }

  fsl_chan->pd_dev = pd_chan;

  pm_runtime_use_autosuspend(fsl_chan->pd_dev);
  pm_runtime_set_autosuspend_delay(fsl_chan->pd_dev, 200);
  pm_runtime_set_active(fsl_chan->pd_dev);
 }

 return 0;

detach:
 fsl_edma3_detach_pd(fsl_edma);
 return -EINVAL;
}

static int fsl_edma_probe(struct platform_device *pdev)
{
 struct device_node *np = pdev->dev.of_node;
 struct fsl_edma_engine *fsl_edma;
 const struct fsl_edma_drvdata *drvdata = NULL;
 u32 chan_mask[2] = {0, 0};
 char clk_name[36];
 struct edma_regs *regs;
 int chans;
 int ret, i;

 drvdata = device_get_match_data(&pdev->dev);
 if (!drvdata) {
  dev_err(&pdev->dev, "unable to find driver data\n");
  return -EINVAL;
 }

 ret = of_property_read_u32(np, "dma-channels", &chans);
 if (ret) {
  dev_err(&pdev->dev, "Can't get dma-channels.\n");
  return ret;
 }

 fsl_edma = devm_kzalloc(&pdev->dev, struct_size(fsl_edma, chans, chans),
    GFP_KERNEL);
 if (!fsl_edma)
  return -ENOMEM;

 fsl_edma->errirq = -EINVAL;
 fsl_edma->txirq = -EINVAL;
 fsl_edma->drvdata = drvdata;
 fsl_edma->n_chans = chans;
 mutex_init(&fsl_edma->fsl_edma_mutex);

 fsl_edma->membase = devm_platform_ioremap_resource(pdev, 0);
 if (IS_ERR(fsl_edma->membase))
  return PTR_ERR(fsl_edma->membase);

 if (!(drvdata->flags & FSL_EDMA_DRV_SPLIT_REG)) {
  fsl_edma_setup_regs(fsl_edma);
  regs = &fsl_edma->regs;
 }

 if (drvdata->flags & FSL_EDMA_DRV_HAS_DMACLK) {
  fsl_edma->dmaclk = devm_clk_get_enabled(&pdev->dev, "dma");
  if (IS_ERR(fsl_edma->dmaclk)) {
   dev_err(&pdev->dev, "Missing DMA block clock.\n");
   return PTR_ERR(fsl_edma->dmaclk);
  }
 }

 ret = of_property_read_variable_u32_array(np, "dma-channel-mask", chan_mask, 1, 2);

 if (ret > 0) {
  fsl_edma->chan_masked = chan_mask[1];
  fsl_edma->chan_masked <<= 32;
  fsl_edma->chan_masked |= chan_mask[0];
 }

 for (i = 0; i < fsl_edma->drvdata->dmamuxs; i++) {
  char clkname[32];

  fsl_edma->muxbase[i] = devm_platform_ioremap_resource(pdev,
              1 + i);
  if (IS_ERR(fsl_edma->muxbase[i])) {
   /* on error: disable all previously enabled clks */
   fsl_disable_clocks(fsl_edma, i);
   return PTR_ERR(fsl_edma->muxbase[i]);
  }

  sprintf(clkname, "dmamux%d", i);
  fsl_edma->muxclk[i] = devm_clk_get_enabled(&pdev->dev, clkname);
  if (IS_ERR(fsl_edma->muxclk[i])) {
   dev_err(&pdev->dev, "Missing DMAMUX block clock.\n");
   /* on error: disable all previously enabled clks */
   return PTR_ERR(fsl_edma->muxclk[i]);
  }
 }

 fsl_edma->big_endian = of_property_read_bool(np, "big-endian");

 if (drvdata->flags & FSL_EDMA_DRV_HAS_PD) {
  ret = fsl_edma3_attach_pd(pdev, fsl_edma);
  if (ret)
   return ret;
  ret = devm_add_action_or_reset(&pdev->dev, devm_fsl_edma3_detach_pd, fsl_edma);
  if (ret)
   return ret;
 }

 if (drvdata->flags & FSL_EDMA_DRV_TCD64)
  dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));

 INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
 for (i = 0; i < fsl_edma->n_chans; i++) {
  struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
  int len;

  if (fsl_edma->chan_masked & BIT(i))
   continue;

  snprintf(fsl_chan->chan_name, sizeof(fsl_chan->chan_name), "%s-CH%02d",
          dev_name(&pdev->dev), i);

  snprintf(fsl_chan->errirq_name, sizeof(fsl_chan->errirq_name),
    "%s-CH%02d-err", dev_name(&pdev->dev), i);

  fsl_chan->edma = fsl_edma;
  fsl_chan->pm_state = RUNNING;
  fsl_chan->srcid = 0;
  fsl_chan->dma_dir = DMA_NONE;
  fsl_chan->vchan.desc_free = fsl_edma_free_desc;

  len = (drvdata->flags & FSL_EDMA_DRV_SPLIT_REG) ?
    offsetof(struct fsl_edma3_ch_reg, tcd) : 0;
  fsl_chan->tcd = fsl_edma->membase
    + i * drvdata->chreg_space_sz + drvdata->chreg_off + len;
  fsl_chan->mux_addr = fsl_edma->membase + drvdata->mux_off + i * drvdata->mux_skip;

  if (drvdata->flags & FSL_EDMA_DRV_HAS_CHCLK) {
   snprintf(clk_name, sizeof(clk_name), "ch%02d", i);
   fsl_chan->clk = devm_clk_get_enabled(&pdev->dev,
            (const char *)clk_name);

   if (IS_ERR(fsl_chan->clk))
    return PTR_ERR(fsl_chan->clk);
  }
  fsl_chan->pdev = pdev;
  vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);

  edma_write_tcdreg(fsl_chan, cpu_to_le32(0), csr);
  fsl_edma_chan_mux(fsl_chan, 0, false);
  if (fsl_chan->edma->drvdata->flags & FSL_EDMA_DRV_HAS_CHCLK)
   clk_disable_unprepare(fsl_chan->clk);
 }

 ret = fsl_edma->drvdata->setup_irq(pdev, fsl_edma);
 if (ret)
  return ret;

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

 fsl_edma->dma_dev.dev = &pdev->dev;
 fsl_edma->dma_dev.device_alloc_chan_resources
  = fsl_edma_alloc_chan_resources;
 fsl_edma->dma_dev.device_free_chan_resources
  = fsl_edma_free_chan_resources;
 fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
 fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
 fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
 fsl_edma->dma_dev.device_prep_dma_memcpy = fsl_edma_prep_memcpy;
 fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
 fsl_edma->dma_dev.device_pause = fsl_edma_pause;
 fsl_edma->dma_dev.device_resume = fsl_edma_resume;
 fsl_edma->dma_dev.device_terminate_all = fsl_edma_terminate_all;
 fsl_edma->dma_dev.device_synchronize = fsl_edma_synchronize;
 fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;

 fsl_edma->dma_dev.src_addr_widths = FSL_EDMA_BUSWIDTHS;
 fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;

 if (drvdata->flags & FSL_EDMA_DRV_BUS_8BYTE) {
  fsl_edma->dma_dev.src_addr_widths |= BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
  fsl_edma->dma_dev.dst_addr_widths |= BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
 }

 fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
 if (drvdata->flags & FSL_EDMA_DRV_DEV_TO_DEV)
  fsl_edma->dma_dev.directions |= BIT(DMA_DEV_TO_DEV);

 fsl_edma->dma_dev.copy_align = drvdata->flags & FSL_EDMA_DRV_ALIGN_64BYTE ?
     DMAENGINE_ALIGN_64_BYTES :
     DMAENGINE_ALIGN_32_BYTES;

 /* Per worst case 'nbytes = 1' take CITER as the max_seg_size */
 dma_set_max_seg_size(fsl_edma->dma_dev.dev,
        FIELD_GET(EDMA_TCD_ITER_MASK, EDMA_TCD_ITER_MASK));

 fsl_edma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;

 platform_set_drvdata(pdev, fsl_edma);

 ret = dma_async_device_register(&fsl_edma->dma_dev);
 if (ret) {
  dev_err(&pdev->dev,
   "Can't register Freescale eDMA engine. (%d)\n", ret);
  return ret;
 }

 ret = of_dma_controller_register(np,
   drvdata->dmamuxs ? fsl_edma_xlate : fsl_edma3_xlate,
   fsl_edma);
 if (ret) {
  dev_err(&pdev->dev,
   "Can't register Freescale eDMA of_dma. (%d)\n", ret);
  dma_async_device_unregister(&fsl_edma->dma_dev);
  return ret;
 }

 /* enable round robin arbitration */
 if (!(drvdata->flags & FSL_EDMA_DRV_SPLIT_REG))
  edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);

 return 0;
}

static void fsl_edma_remove(struct platform_device *pdev)
{
 struct device_node *np = pdev->dev.of_node;
 struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);

 fsl_edma_irq_exit(pdev, fsl_edma);
 of_dma_controller_free(np);
 dma_async_device_unregister(&fsl_edma->dma_dev);
 fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
 fsl_disable_clocks(fsl_edma, fsl_edma->drvdata->dmamuxs);
}

static int fsl_edma_suspend_late(struct device *dev)
{
 struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
 struct fsl_edma_chan *fsl_chan;
 unsigned long flags;
 int i;

 for (i = 0; i < fsl_edma->n_chans; i++) {
  fsl_chan = &fsl_edma->chans[i];
  if (fsl_edma->chan_masked & BIT(i))
   continue;
  spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
  /* Make sure chan is idle or will force disable. */
  if (unlikely(fsl_chan->status == DMA_IN_PROGRESS)) {
   dev_warn(dev, "WARN: There is non-idle channel.\n");
   fsl_edma_disable_request(fsl_chan);
   fsl_edma_chan_mux(fsl_chan, 0, false);
  }

  fsl_chan->pm_state = SUSPENDED;
  spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 }

 return 0;
}

static int fsl_edma_resume_early(struct device *dev)
{
 struct fsl_edma_engine *fsl_edma = dev_get_drvdata(dev);
 struct fsl_edma_chan *fsl_chan;
 struct edma_regs *regs = &fsl_edma->regs;
 int i;

 for (i = 0; i < fsl_edma->n_chans; i++) {
  fsl_chan = &fsl_edma->chans[i];
  if (fsl_edma->chan_masked & BIT(i))
   continue;
  fsl_chan->pm_state = RUNNING;
  edma_write_tcdreg(fsl_chan, 0, csr);
  if (fsl_chan->srcid != 0)
   fsl_edma_chan_mux(fsl_chan, fsl_chan->srcid, true);
 }

 if (!(fsl_edma->drvdata->flags & FSL_EDMA_DRV_SPLIT_REG))
  edma_writel(fsl_edma, EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);

 return 0;
}

/*
 * eDMA provides the service to others, so it should be suspend late
 * and resume early. When eDMA suspend, all of the clients should stop
 * the DMA data transmission and let the channel idle.
 */
static const struct dev_pm_ops fsl_edma_pm_ops = {
 .suspend_late   = fsl_edma_suspend_late,
 .resume_early   = fsl_edma_resume_early,
};

static struct platform_driver fsl_edma_driver = {
 .driver  = {
  .name = "fsl-edma",
  .of_match_table = fsl_edma_dt_ids,
  .pm     = &fsl_edma_pm_ops,
 },
 .probe          = fsl_edma_probe,
 .remove  = fsl_edma_remove,
};

static int __init fsl_edma_init(void)
{
 return platform_driver_register(&fsl_edma_driver);
}
subsys_initcall(fsl_edma_init);

static void __exit fsl_edma_exit(void)
{
 platform_driver_unregister(&fsl_edma_driver);
}
module_exit(fsl_edma_exit);

MODULE_ALIAS("platform:fsl-edma");
MODULE_DESCRIPTION("Freescale eDMA engine driver");
MODULE_LICENSE("GPL v2");