root/drivers/dma/fsl-edma-main.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;

                if (!b_chmux && i != dma_spec->args[0])
                        continue;

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

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

                fsl_chan->srcid = dma_spec->args[0];
                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;

                chan = dma_get_slave_channel(chan);
                chan->device->privatecnt++;
                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)
                return dev_err_probe(&pdev->dev, -EINVAL,
                                     "unable to find driver data\n");

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

        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))
                        return dev_err_probe(&pdev->dev,
                                             PTR_ERR(fsl_edma->dmaclk),
                                             "Missing DMA block clock.\n");
        }

        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]))
                        return dev_err_probe(&pdev->dev,
                                             PTR_ERR(fsl_edma->muxclk[i]),
                                             "Missing DMAMUX block clock.\n");
        }

        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 = dmaenginem_async_device_register(&fsl_edma->dma_dev);
        if (ret)
                return dev_err_probe(&pdev->dev, ret,
                                     "Can't register Freescale eDMA engine.\n");

        ret = devm_of_dma_controller_register(&pdev->dev, np,
                        drvdata->dmamuxs ? fsl_edma_xlate : fsl_edma3_xlate,
                        fsl_edma);
        if (ret)
                return dev_err_probe(&pdev->dev, ret,
                                     "Can't register Freescale eDMA of_dma.\n");

        /* 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 fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);

        fsl_edma_irq_exit(pdev, fsl_edma);
        fsl_edma_cleanup_vchan(&fsl_edma->dma_dev);
}

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_DESCRIPTION("Freescale eDMA engine driver");
MODULE_LICENSE("GPL v2");