// SPDX-License-Identifier: GPL-2.0
/*
 * MMCIF eMMC driver.
 *
 * Copyright (C) 2010 Renesas Solutions Corp.
 * Yusuke Goda <yusuke.goda.sx@renesas.com>
 */

/*
 * The MMCIF driver is now processing MMC requests asynchronously, according
 * to the Linux MMC API requirement.
 *
 * The MMCIF driver processes MMC requests in up to 3 stages: command, optional
 * data, and optional stop. To achieve asynchronous processing each of these
 * stages is split into two halves: a top and a bottom half. The top half
 * initialises the hardware, installs a timeout handler to handle completion
 * timeouts, and returns. In case of the command stage this immediately returns
 * control to the caller, leaving all further processing to run asynchronously.
 * All further request processing is performed by the bottom halves.
 *
 * The bottom half further consists of a "hard" IRQ handler, an IRQ handler
 * thread, a DMA completion callback, if DMA is used, a timeout work, and
 * request- and stage-specific handler methods.
 *
 * Each bottom half run begins with either a hardware interrupt, a DMA callback
 * invocation, or a timeout work run. In case of an error or a successful
 * processing completion, the MMC core is informed and the request processing is
 * finished. In case processing has to continue, i.e., if data has to be read
 * from or written to the card, or if a stop command has to be sent, the next
 * top half is called, which performs the necessary hardware handling and
 * reschedules the timeout work. This returns the driver state machine into the
 * bottom half waiting state.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/mmc/card.h>
#include <linux/mmc/core.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/pagemap.h>
#include <linux/platform_data/sh_mmcif.h>
#include <linux/platform_device.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/spinlock.h>
#include <linux/module.h>

#define DRIVER_NAME     "sh_mmcif"

/* CE_CMD_SET */
#define CMD_MASK                0x3f000000
#define CMD_SET_RTYP_NO         ((0 << 23) | (0 << 22))
#define CMD_SET_RTYP_6B         ((0 << 23) | (1 << 22)) /* R1/R1b/R3/R4/R5 */
#define CMD_SET_RTYP_17B        ((1 << 23) | (0 << 22)) /* R2 */
#define CMD_SET_RBSY            (1 << 21) /* R1b */
#define CMD_SET_CCSEN           (1 << 20)
#define CMD_SET_WDAT            (1 << 19) /* 1: on data, 0: no data */
#define CMD_SET_DWEN            (1 << 18) /* 1: write, 0: read */
#define CMD_SET_CMLTE           (1 << 17) /* 1: multi block trans, 0: single */
#define CMD_SET_CMD12EN         (1 << 16) /* 1: CMD12 auto issue */
#define CMD_SET_RIDXC_INDEX     ((0 << 15) | (0 << 14)) /* index check */
#define CMD_SET_RIDXC_BITS      ((0 << 15) | (1 << 14)) /* check bits check */
#define CMD_SET_RIDXC_NO        ((1 << 15) | (0 << 14)) /* no check */
#define CMD_SET_CRC7C           ((0 << 13) | (0 << 12)) /* CRC7 check*/
#define CMD_SET_CRC7C_BITS      ((0 << 13) | (1 << 12)) /* check bits check*/
#define CMD_SET_CRC7C_INTERNAL  ((1 << 13) | (0 << 12)) /* internal CRC7 check*/
#define CMD_SET_CRC16C          (1 << 10) /* 0: CRC16 check*/
#define CMD_SET_CRCSTE          (1 << 8) /* 1: not receive CRC status */
#define CMD_SET_TBIT            (1 << 7) /* 1: tran mission bit "Low" */
#define CMD_SET_OPDM            (1 << 6) /* 1: open/drain */
#define CMD_SET_CCSH            (1 << 5)
#define CMD_SET_DARS            (1 << 2) /* Dual Data Rate */
#define CMD_SET_DATW_1          ((0 << 1) | (0 << 0)) /* 1bit */
#define CMD_SET_DATW_4          ((0 << 1) | (1 << 0)) /* 4bit */
#define CMD_SET_DATW_8          ((1 << 1) | (0 << 0)) /* 8bit */

/* CE_CMD_CTRL */
#define CMD_CTRL_BREAK          (1 << 0)

/* CE_BLOCK_SET */
#define BLOCK_SIZE_MASK         0x0000ffff

/* CE_INT */
#define INT_CCSDE               (1 << 29)
#define INT_CMD12DRE            (1 << 26)
#define INT_CMD12RBE            (1 << 25)
#define INT_CMD12CRE            (1 << 24)
#define INT_DTRANE              (1 << 23)
#define INT_BUFRE               (1 << 22)
#define INT_BUFWEN              (1 << 21)
#define INT_BUFREN              (1 << 20)
#define INT_CCSRCV              (1 << 19)
#define INT_RBSYE               (1 << 17)
#define INT_CRSPE               (1 << 16)
#define INT_CMDVIO              (1 << 15)
#define INT_BUFVIO              (1 << 14)
#define INT_WDATERR             (1 << 11)
#define INT_RDATERR             (1 << 10)
#define INT_RIDXERR             (1 << 9)
#define INT_RSPERR              (1 << 8)
#define INT_CCSTO               (1 << 5)
#define INT_CRCSTO              (1 << 4)
#define INT_WDATTO              (1 << 3)
#define INT_RDATTO              (1 << 2)
#define INT_RBSYTO              (1 << 1)
#define INT_RSPTO               (1 << 0)
#define INT_ERR_STS             (INT_CMDVIO | INT_BUFVIO | INT_WDATERR |  \
                                 INT_RDATERR | INT_RIDXERR | INT_RSPERR | \
                                 INT_CCSTO | INT_CRCSTO | INT_WDATTO |    \
                                 INT_RDATTO | INT_RBSYTO | INT_RSPTO)

#define INT_ALL                 (INT_RBSYE | INT_CRSPE | INT_BUFREN |    \
                                 INT_BUFWEN | INT_CMD12DRE | INT_BUFRE | \
                                 INT_DTRANE | INT_CMD12RBE | INT_CMD12CRE)

#define INT_CCS                 (INT_CCSTO | INT_CCSRCV | INT_CCSDE)

/* CE_INT_MASK */
#define MASK_ALL                0x00000000
#define MASK_MCCSDE             (1 << 29)
#define MASK_MCMD12DRE          (1 << 26)
#define MASK_MCMD12RBE          (1 << 25)
#define MASK_MCMD12CRE          (1 << 24)
#define MASK_MDTRANE            (1 << 23)
#define MASK_MBUFRE             (1 << 22)
#define MASK_MBUFWEN            (1 << 21)
#define MASK_MBUFREN            (1 << 20)
#define MASK_MCCSRCV            (1 << 19)
#define MASK_MRBSYE             (1 << 17)
#define MASK_MCRSPE             (1 << 16)
#define MASK_MCMDVIO            (1 << 15)
#define MASK_MBUFVIO            (1 << 14)
#define MASK_MWDATERR           (1 << 11)
#define MASK_MRDATERR           (1 << 10)
#define MASK_MRIDXERR           (1 << 9)
#define MASK_MRSPERR            (1 << 8)
#define MASK_MCCSTO             (1 << 5)
#define MASK_MCRCSTO            (1 << 4)
#define MASK_MWDATTO            (1 << 3)
#define MASK_MRDATTO            (1 << 2)
#define MASK_MRBSYTO            (1 << 1)
#define MASK_MRSPTO             (1 << 0)

#define MASK_START_CMD          (MASK_MCMDVIO | MASK_MBUFVIO | MASK_MWDATERR | \
                                 MASK_MRDATERR | MASK_MRIDXERR | MASK_MRSPERR | \
                                 MASK_MCRCSTO | MASK_MWDATTO | \
                                 MASK_MRDATTO | MASK_MRBSYTO | MASK_MRSPTO)

#define MASK_CLEAN              (INT_ERR_STS | MASK_MRBSYE | MASK_MCRSPE |      \
                                 MASK_MBUFREN | MASK_MBUFWEN |                  \
                                 MASK_MCMD12DRE | MASK_MBUFRE | MASK_MDTRANE |  \
                                 MASK_MCMD12RBE | MASK_MCMD12CRE)

/* CE_HOST_STS1 */
#define STS1_CMDSEQ             (1 << 31)

/* CE_HOST_STS2 */
#define STS2_CRCSTE             (1 << 31)
#define STS2_CRC16E             (1 << 30)
#define STS2_AC12CRCE           (1 << 29)
#define STS2_RSPCRC7E           (1 << 28)
#define STS2_CRCSTEBE           (1 << 27)
#define STS2_RDATEBE            (1 << 26)
#define STS2_AC12REBE           (1 << 25)
#define STS2_RSPEBE             (1 << 24)
#define STS2_AC12IDXE           (1 << 23)
#define STS2_RSPIDXE            (1 << 22)
#define STS2_CCSTO              (1 << 15)
#define STS2_RDATTO             (1 << 14)
#define STS2_DATBSYTO           (1 << 13)
#define STS2_CRCSTTO            (1 << 12)
#define STS2_AC12BSYTO          (1 << 11)
#define STS2_RSPBSYTO           (1 << 10)
#define STS2_AC12RSPTO          (1 << 9)
#define STS2_RSPTO              (1 << 8)
#define STS2_CRC_ERR            (STS2_CRCSTE | STS2_CRC16E |            \
                                 STS2_AC12CRCE | STS2_RSPCRC7E | STS2_CRCSTEBE)
#define STS2_TIMEOUT_ERR        (STS2_CCSTO | STS2_RDATTO |             \
                                 STS2_DATBSYTO | STS2_CRCSTTO |         \
                                 STS2_AC12BSYTO | STS2_RSPBSYTO |       \
                                 STS2_AC12RSPTO | STS2_RSPTO)

#define CLKDEV_EMMC_DATA        52000000 /* 52 MHz */
#define CLKDEV_MMC_DATA         20000000 /* 20 MHz */
#define CLKDEV_INIT             400000   /* 400 kHz */

enum sh_mmcif_state {
        STATE_IDLE,
        STATE_REQUEST,
        STATE_IOS,
        STATE_TIMEOUT,
};

enum sh_mmcif_wait_for {
        MMCIF_WAIT_FOR_REQUEST,
        MMCIF_WAIT_FOR_CMD,
        MMCIF_WAIT_FOR_MREAD,
        MMCIF_WAIT_FOR_MWRITE,
        MMCIF_WAIT_FOR_READ,
        MMCIF_WAIT_FOR_WRITE,
        MMCIF_WAIT_FOR_READ_END,
        MMCIF_WAIT_FOR_WRITE_END,
        MMCIF_WAIT_FOR_STOP,
};

/*
 * difference for each SoC
 */
struct sh_mmcif_host {
        struct mmc_host *mmc;
        struct mmc_request *mrq;
        struct platform_device *pd;
        struct clk *clk;
        int bus_width;
        unsigned char timing;
        bool sd_error;
        bool dying;
        long timeout;
        void __iomem *addr;
        spinlock_t lock;                /* protect sh_mmcif_host::state */
        enum sh_mmcif_state state;
        enum sh_mmcif_wait_for wait_for;
        struct delayed_work timeout_work;
        size_t blocksize;
        struct sg_mapping_iter sg_miter;
        bool power;
        bool ccs_enable;                /* Command Completion Signal support */
        bool clk_ctrl2_enable;
        struct mutex thread_lock;
        u32 clkdiv_map;         /* see CE_CLK_CTRL::CLKDIV */

        /* DMA support */
        struct dma_chan         *chan_rx;
        struct dma_chan         *chan_tx;
        struct completion       dma_complete;
        bool                    dma_active;
};

static const struct of_device_id sh_mmcif_of_match[] = {
        { .compatible = "renesas,sh-mmcif" },
        { }
};
MODULE_DEVICE_TABLE(of, sh_mmcif_of_match);

#define sh_mmcif_host_to_dev(host) (&host->pd->dev)

static inline void sh_mmcif_bitset(struct sh_mmcif_host *host,
                                        unsigned int reg, u32 val)
{
        writel(val | readl(host->addr + reg), host->addr + reg);
}

static inline void sh_mmcif_bitclr(struct sh_mmcif_host *host,
                                        unsigned int reg, u32 val)
{
        writel(~val & readl(host->addr + reg), host->addr + reg);
}

static void sh_mmcif_dma_complete(void *arg)
{
        struct sh_mmcif_host *host = arg;
        struct mmc_request *mrq = host->mrq;
        struct device *dev = sh_mmcif_host_to_dev(host);

        dev_dbg(dev, "Command completed\n");

        if (WARN(!mrq || !mrq->data, "%s: NULL data in DMA completion!\n",
                 dev_name(dev)))
                return;

        complete(&host->dma_complete);
}

static void sh_mmcif_start_dma_rx(struct sh_mmcif_host *host)
{
        struct mmc_data *data = host->mrq->data;
        struct scatterlist *sg = data->sg;
        struct dma_async_tx_descriptor *desc = NULL;
        struct dma_chan *chan = host->chan_rx;
        struct device *dev = sh_mmcif_host_to_dev(host);
        dma_cookie_t cookie = -EINVAL;
        int ret;

        ret = dma_map_sg(chan->device->dev, sg, data->sg_len,
                         DMA_FROM_DEVICE);
        if (ret > 0) {
                host->dma_active = true;
                desc = dmaengine_prep_slave_sg(chan, sg, ret,
                        DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        }

        if (desc) {
                desc->callback = sh_mmcif_dma_complete;
                desc->callback_param = host;
                cookie = dmaengine_submit(desc);
                sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN);
                dma_async_issue_pending(chan);
        }
        dev_dbg(dev, "%s(): mapped %d -> %d, cookie %d\n",
                __func__, data->sg_len, ret, cookie);

        if (!desc) {
                /* DMA failed, fall back to PIO */
                if (ret >= 0)
                        ret = -EIO;
                host->chan_rx = NULL;
                host->dma_active = false;
                dma_release_channel(chan);
                /* Free the Tx channel too */
                chan = host->chan_tx;
                if (chan) {
                        host->chan_tx = NULL;
                        dma_release_channel(chan);
                }
                dev_warn(dev,
                         "DMA failed: %d, falling back to PIO\n", ret);
                sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN);
        }

        dev_dbg(dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
                desc, cookie, data->sg_len);
}

static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host)
{
        struct mmc_data *data = host->mrq->data;
        struct scatterlist *sg = data->sg;
        struct dma_async_tx_descriptor *desc = NULL;
        struct dma_chan *chan = host->chan_tx;
        struct device *dev = sh_mmcif_host_to_dev(host);
        dma_cookie_t cookie = -EINVAL;
        int ret;

        ret = dma_map_sg(chan->device->dev, sg, data->sg_len,
                         DMA_TO_DEVICE);
        if (ret > 0) {
                host->dma_active = true;
                desc = dmaengine_prep_slave_sg(chan, sg, ret,
                        DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        }

        if (desc) {
                desc->callback = sh_mmcif_dma_complete;
                desc->callback_param = host;
                cookie = dmaengine_submit(desc);
                sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAWEN);
                dma_async_issue_pending(chan);
        }
        dev_dbg(dev, "%s(): mapped %d -> %d, cookie %d\n",
                __func__, data->sg_len, ret, cookie);

        if (!desc) {
                /* DMA failed, fall back to PIO */
                if (ret >= 0)
                        ret = -EIO;
                host->chan_tx = NULL;
                host->dma_active = false;
                dma_release_channel(chan);
                /* Free the Rx channel too */
                chan = host->chan_rx;
                if (chan) {
                        host->chan_rx = NULL;
                        dma_release_channel(chan);
                }
                dev_warn(dev,
                         "DMA failed: %d, falling back to PIO\n", ret);
                sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN);
        }

        dev_dbg(dev, "%s(): desc %p, cookie %d\n", __func__,
                desc, cookie);
}

static struct dma_chan *
sh_mmcif_request_dma_pdata(struct sh_mmcif_host *host, uintptr_t slave_id)
{
        dma_cap_mask_t mask;

        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
        if (slave_id <= 0)
                return NULL;

        return dma_request_channel(mask, shdma_chan_filter, (void *)slave_id);
}

static int sh_mmcif_dma_slave_config(struct sh_mmcif_host *host,
                                     struct dma_chan *chan,
                                     enum dma_transfer_direction direction)
{
        struct resource *res;
        struct dma_slave_config cfg = { 0, };

        res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
        if (!res)
                return -EINVAL;

        cfg.direction = direction;

        if (direction == DMA_DEV_TO_MEM) {
                cfg.src_addr = res->start + MMCIF_CE_DATA;
                cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        } else {
                cfg.dst_addr = res->start + MMCIF_CE_DATA;
                cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        }

        return dmaengine_slave_config(chan, &cfg);
}

static void sh_mmcif_request_dma(struct sh_mmcif_host *host)
{
        struct device *dev = sh_mmcif_host_to_dev(host);
        host->dma_active = false;

        /* We can only either use DMA for both Tx and Rx or not use it at all */
        if (IS_ENABLED(CONFIG_SUPERH) && dev->platform_data) {
                struct sh_mmcif_plat_data *pdata = dev->platform_data;

                host->chan_tx = sh_mmcif_request_dma_pdata(host,
                                                        pdata->slave_id_tx);
                host->chan_rx = sh_mmcif_request_dma_pdata(host,
                                                        pdata->slave_id_rx);
        } else {
                host->chan_tx = dma_request_chan(dev, "tx");
                if (IS_ERR(host->chan_tx))
                        host->chan_tx = NULL;
                host->chan_rx = dma_request_chan(dev, "rx");
                if (IS_ERR(host->chan_rx))
                        host->chan_rx = NULL;
        }

        if (!host->chan_tx || !host->chan_rx ||
            sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) ||
            sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM))
                goto error;

        dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx,
                host->chan_rx);

        return;

error:
        if (host->chan_tx)
                dma_release_channel(host->chan_tx);
        if (host->chan_rx)
                dma_release_channel(host->chan_rx);
        host->chan_tx = host->chan_rx = NULL;
}

static void sh_mmcif_release_dma(struct sh_mmcif_host *host)
{
        sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC, BUF_ACC_DMAREN | BUF_ACC_DMAWEN);
        /* Descriptors are freed automatically */
        if (host->chan_tx) {
                struct dma_chan *chan = host->chan_tx;
                host->chan_tx = NULL;
                dma_release_channel(chan);
        }
        if (host->chan_rx) {
                struct dma_chan *chan = host->chan_rx;
                host->chan_rx = NULL;
                dma_release_channel(chan);
        }

        host->dma_active = false;
}

static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
{
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct sh_mmcif_plat_data *p = dev->platform_data;
        bool sup_pclk = p ? p->sup_pclk : false;
        unsigned int current_clk = clk_get_rate(host->clk);
        unsigned int clkdiv;

        sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
        sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR);

        if (!clk)
                return;

        if (host->clkdiv_map) {
                unsigned int freq, best_freq, myclk, div, diff_min, diff;
                int i;

                clkdiv = 0;
                diff_min = ~0;
                best_freq = 0;
                for (i = 31; i >= 0; i--) {
                        if (!((1 << i) & host->clkdiv_map))
                                continue;

                        /*
                         * clk = parent_freq / div
                         * -> parent_freq = clk x div
                         */

                        div = 1 << (i + 1);
                        freq = clk_round_rate(host->clk, clk * div);
                        myclk = freq / div;
                        diff = (myclk > clk) ? myclk - clk : clk - myclk;

                        if (diff <= diff_min) {
                                best_freq = freq;
                                clkdiv = i;
                                diff_min = diff;
                        }
                }

                dev_dbg(dev, "clk %u/%u (%u, 0x%x)\n",
                        (best_freq >> (clkdiv + 1)), clk, best_freq, clkdiv);

                clk_set_rate(host->clk, best_freq);
                clkdiv = clkdiv << 16;
        } else if (sup_pclk && clk == current_clk) {
                clkdiv = CLK_SUP_PCLK;
        } else {
                clkdiv = (fls(DIV_ROUND_UP(current_clk, clk) - 1) - 1) << 16;
        }

        sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR & clkdiv);
        sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
}

static void sh_mmcif_sync_reset(struct sh_mmcif_host *host)
{
        u32 tmp;

        tmp = 0x010f0000 & sh_mmcif_readl(host->addr, MMCIF_CE_CLK_CTRL);

        sh_mmcif_writel(host->addr, MMCIF_CE_VERSION, SOFT_RST_ON);
        sh_mmcif_writel(host->addr, MMCIF_CE_VERSION, SOFT_RST_OFF);
        if (host->ccs_enable)
                tmp |= SCCSTO_29;
        if (host->clk_ctrl2_enable)
                sh_mmcif_writel(host->addr, MMCIF_CE_CLK_CTRL2, 0x0F0F0000);
        sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, tmp |
                SRSPTO_256 | SRBSYTO_29 | SRWDTO_29);
        /* byte swap on */
        sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_ATYP);
}

static int sh_mmcif_error_manage(struct sh_mmcif_host *host)
{
        struct device *dev = sh_mmcif_host_to_dev(host);
        u32 state1, state2;
        int ret, timeout;

        host->sd_error = false;

        state1 = sh_mmcif_readl(host->addr, MMCIF_CE_HOST_STS1);
        state2 = sh_mmcif_readl(host->addr, MMCIF_CE_HOST_STS2);
        dev_dbg(dev, "ERR HOST_STS1 = %08x\n", state1);
        dev_dbg(dev, "ERR HOST_STS2 = %08x\n", state2);

        if (state1 & STS1_CMDSEQ) {
                sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, CMD_CTRL_BREAK);
                sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, ~CMD_CTRL_BREAK);
                for (timeout = 10000; timeout; timeout--) {
                        if (!(sh_mmcif_readl(host->addr, MMCIF_CE_HOST_STS1)
                              & STS1_CMDSEQ))
                                break;
                        mdelay(1);
                }
                if (!timeout) {
                        dev_err(dev,
                                "Forced end of command sequence timeout err\n");
                        return -EIO;
                }
                sh_mmcif_sync_reset(host);
                dev_dbg(dev, "Forced end of command sequence\n");
                return -EIO;
        }

        if (state2 & STS2_CRC_ERR) {
                dev_err(dev, " CRC error: state %u, wait %u\n",
                        host->state, host->wait_for);
                ret = -EIO;
        } else if (state2 & STS2_TIMEOUT_ERR) {
                dev_err(dev, " Timeout: state %u, wait %u\n",
                        host->state, host->wait_for);
                ret = -ETIMEDOUT;
        } else {
                dev_dbg(dev, " End/Index error: state %u, wait %u\n",
                        host->state, host->wait_for);
                ret = -EIO;
        }
        return ret;
}

static void sh_mmcif_single_read(struct sh_mmcif_host *host,
                                 struct mmc_request *mrq)
{
        struct mmc_data *data = mrq->data;

        host->blocksize = (sh_mmcif_readl(host->addr, MMCIF_CE_BLOCK_SET) &
                           BLOCK_SIZE_MASK) + 3;

        sg_miter_start(&host->sg_miter, data->sg, data->sg_len,
                       SG_MITER_TO_SG);

        host->wait_for = MMCIF_WAIT_FOR_READ;

        /* buf read enable */
        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
}

static bool sh_mmcif_read_block(struct sh_mmcif_host *host)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct mmc_data *data = host->mrq->data;
        u32 *p;
        int i;

        if (host->sd_error) {
                sg_miter_stop(sgm);
                data->error = sh_mmcif_error_manage(host);
                dev_dbg(dev, "%s(): %d\n", __func__, data->error);
                return false;
        }

        if (!sg_miter_next(sgm)) {
                /* This should not happen on single blocks */
                sg_miter_stop(sgm);
                return false;
        }

        p = sgm->addr;

        for (i = 0; i < host->blocksize / 4; i++)
                *p++ = sh_mmcif_readl(host->addr, MMCIF_CE_DATA);

        sg_miter_stop(&host->sg_miter);

        /* buffer read end */
        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFRE);
        host->wait_for = MMCIF_WAIT_FOR_READ_END;

        return true;
}

static void sh_mmcif_multi_read(struct sh_mmcif_host *host,
                                struct mmc_request *mrq)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct mmc_data *data = mrq->data;

        if (!data->sg_len || !data->sg->length)
                return;

        host->blocksize = sh_mmcif_readl(host->addr, MMCIF_CE_BLOCK_SET) &
                BLOCK_SIZE_MASK;

        sg_miter_start(sgm, data->sg, data->sg_len,
                       SG_MITER_TO_SG);

        /* Advance to the first sglist entry */
        if (!sg_miter_next(sgm)) {
                sg_miter_stop(sgm);
                return;
        }

        host->wait_for = MMCIF_WAIT_FOR_MREAD;

        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
}

static bool sh_mmcif_mread_block(struct sh_mmcif_host *host)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct mmc_data *data = host->mrq->data;
        u32 *p;
        int i;

        if (host->sd_error) {
                sg_miter_stop(sgm);
                data->error = sh_mmcif_error_manage(host);
                dev_dbg(dev, "%s(): %d\n", __func__, data->error);
                return false;
        }

        p = sgm->addr;

        for (i = 0; i < host->blocksize / 4; i++)
                *p++ = sh_mmcif_readl(host->addr, MMCIF_CE_DATA);

        sgm->consumed = host->blocksize;

        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);

        if (!sg_miter_next(sgm)) {
                sg_miter_stop(sgm);
                return false;
        }

        return true;
}

static void sh_mmcif_single_write(struct sh_mmcif_host *host,
                                        struct mmc_request *mrq)
{
        struct mmc_data *data = mrq->data;

        host->blocksize = (sh_mmcif_readl(host->addr, MMCIF_CE_BLOCK_SET) &
                           BLOCK_SIZE_MASK) + 3;

        sg_miter_start(&host->sg_miter, data->sg, data->sg_len,
                       SG_MITER_FROM_SG);

        host->wait_for = MMCIF_WAIT_FOR_WRITE;

        /* buf write enable */
        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
}

static bool sh_mmcif_write_block(struct sh_mmcif_host *host)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct mmc_data *data = host->mrq->data;
        u32 *p;
        int i;

        if (host->sd_error) {
                sg_miter_stop(sgm);
                data->error = sh_mmcif_error_manage(host);
                dev_dbg(dev, "%s(): %d\n", __func__, data->error);
                return false;
        }

        if (!sg_miter_next(sgm)) {
                /* This should not happen on single blocks */
                sg_miter_stop(sgm);
                return false;
        }

        p = sgm->addr;

        for (i = 0; i < host->blocksize / 4; i++)
                sh_mmcif_writel(host->addr, MMCIF_CE_DATA, *p++);

        sg_miter_stop(&host->sg_miter);

        /* buffer write end */
        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MDTRANE);
        host->wait_for = MMCIF_WAIT_FOR_WRITE_END;

        return true;
}

static void sh_mmcif_multi_write(struct sh_mmcif_host *host,
                                struct mmc_request *mrq)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct mmc_data *data = mrq->data;

        if (!data->sg_len || !data->sg->length)
                return;

        host->blocksize = sh_mmcif_readl(host->addr, MMCIF_CE_BLOCK_SET) &
                BLOCK_SIZE_MASK;

        sg_miter_start(sgm, data->sg, data->sg_len,
                       SG_MITER_FROM_SG);

        /* Advance to the first sglist entry */
        if (!sg_miter_next(sgm)) {
                sg_miter_stop(sgm);
                return;
        }

        host->wait_for = MMCIF_WAIT_FOR_MWRITE;

        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
}

static bool sh_mmcif_mwrite_block(struct sh_mmcif_host *host)
{
        struct sg_mapping_iter *sgm = &host->sg_miter;
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct mmc_data *data = host->mrq->data;
        u32 *p;
        int i;

        if (host->sd_error) {
                sg_miter_stop(sgm);
                data->error = sh_mmcif_error_manage(host);
                dev_dbg(dev, "%s(): %d\n", __func__, data->error);
                return false;
        }

        p = sgm->addr;

        for (i = 0; i < host->blocksize / 4; i++)
                sh_mmcif_writel(host->addr, MMCIF_CE_DATA, *p++);

        sgm->consumed = host->blocksize;

        if (!sg_miter_next(sgm)) {
                sg_miter_stop(sgm);
                return false;
        }

        sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);

        return true;
}

static void sh_mmcif_get_response(struct sh_mmcif_host *host,
                                                struct mmc_command *cmd)
{
        if (cmd->flags & MMC_RSP_136) {
                cmd->resp[0] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP3);
                cmd->resp[1] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP2);
                cmd->resp[2] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP1);
                cmd->resp[3] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP0);
        } else
                cmd->resp[0] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP0);
}

static void sh_mmcif_get_cmd12response(struct sh_mmcif_host *host,
                                                struct mmc_command *cmd)
{
        cmd->resp[0] = sh_mmcif_readl(host->addr, MMCIF_CE_RESP_CMD12);
}

static u32 sh_mmcif_set_cmd(struct sh_mmcif_host *host,
                            struct mmc_request *mrq)
{
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct mmc_data *data = mrq->data;
        struct mmc_command *cmd = mrq->cmd;
        u32 opc = cmd->opcode;
        u32 tmp = 0;

        /* Response Type check */
        switch (mmc_resp_type(cmd)) {
        case MMC_RSP_NONE:
                tmp |= CMD_SET_RTYP_NO;
                break;
        case MMC_RSP_R1:
        case MMC_RSP_R3:
                tmp |= CMD_SET_RTYP_6B;
                break;
        case MMC_RSP_R1B:
                tmp |= CMD_SET_RBSY | CMD_SET_RTYP_6B;
                break;
        case MMC_RSP_R2:
                tmp |= CMD_SET_RTYP_17B;
                break;
        default:
                dev_err(dev, "Unsupported response type.\n");
                break;
        }

        /* WDAT / DATW */
        if (data) {
                tmp |= CMD_SET_WDAT;
                switch (host->bus_width) {
                case MMC_BUS_WIDTH_1:
                        tmp |= CMD_SET_DATW_1;
                        break;
                case MMC_BUS_WIDTH_4:
                        tmp |= CMD_SET_DATW_4;
                        break;
                case MMC_BUS_WIDTH_8:
                        tmp |= CMD_SET_DATW_8;
                        break;
                default:
                        dev_err(dev, "Unsupported bus width.\n");
                        break;
                }
                switch (host->timing) {
                case MMC_TIMING_MMC_DDR52:
                        /*
                         * MMC core will only set this timing, if the host
                         * advertises the MMC_CAP_1_8V_DDR/MMC_CAP_1_2V_DDR
                         * capability. MMCIF implementations with this
                         * capability, e.g. sh73a0, will have to set it
                         * in their platform data.
                         */
                        tmp |= CMD_SET_DARS;
                        break;
                }
        }
        /* DWEN */
        if (opc == MMC_WRITE_BLOCK || opc == MMC_WRITE_MULTIPLE_BLOCK)
                tmp |= CMD_SET_DWEN;
        /* CMLTE/CMD12EN */
        if (opc == MMC_READ_MULTIPLE_BLOCK || opc == MMC_WRITE_MULTIPLE_BLOCK) {
                tmp |= CMD_SET_CMLTE | CMD_SET_CMD12EN;
                sh_mmcif_bitset(host, MMCIF_CE_BLOCK_SET,
                                data->blocks << 16);
        }
        /* RIDXC[1:0] check bits */
        if (opc == MMC_SEND_OP_COND || opc == MMC_ALL_SEND_CID ||
            opc == MMC_SEND_CSD || opc == MMC_SEND_CID)
                tmp |= CMD_SET_RIDXC_BITS;
        /* RCRC7C[1:0] check bits */
        if (opc == MMC_SEND_OP_COND)
                tmp |= CMD_SET_CRC7C_BITS;
        /* RCRC7C[1:0] internal CRC7 */
        if (opc == MMC_ALL_SEND_CID ||
                opc == MMC_SEND_CSD || opc == MMC_SEND_CID)
                tmp |= CMD_SET_CRC7C_INTERNAL;

        return (opc << 24) | tmp;
}

static int sh_mmcif_data_trans(struct sh_mmcif_host *host,
                               struct mmc_request *mrq, u32 opc)
{
        struct device *dev = sh_mmcif_host_to_dev(host);

        switch (opc) {
        case MMC_READ_MULTIPLE_BLOCK:
                sh_mmcif_multi_read(host, mrq);
                return 0;
        case MMC_WRITE_MULTIPLE_BLOCK:
                sh_mmcif_multi_write(host, mrq);
                return 0;
        case MMC_WRITE_BLOCK:
                sh_mmcif_single_write(host, mrq);
                return 0;
        case MMC_READ_SINGLE_BLOCK:
        case MMC_SEND_EXT_CSD:
                sh_mmcif_single_read(host, mrq);
                return 0;
        default:
                dev_err(dev, "Unsupported CMD%d\n", opc);
                return -EINVAL;
        }
}

static void sh_mmcif_start_cmd(struct sh_mmcif_host *host,
                               struct mmc_request *mrq)
{
        struct mmc_command *cmd = mrq->cmd;
        u32 opc;
        u32 mask = 0;
        unsigned long flags;

        if (cmd->flags & MMC_RSP_BUSY)
                mask = MASK_START_CMD | MASK_MRBSYE;
        else
                mask = MASK_START_CMD | MASK_MCRSPE;

        if (host->ccs_enable)
                mask |= MASK_MCCSTO;

        if (mrq->data) {
                sh_mmcif_writel(host->addr, MMCIF_CE_BLOCK_SET, 0);
                sh_mmcif_writel(host->addr, MMCIF_CE_BLOCK_SET,
                                mrq->data->blksz);
        }
        opc = sh_mmcif_set_cmd(host, mrq);

        if (host->ccs_enable)
                sh_mmcif_writel(host->addr, MMCIF_CE_INT, 0xD80430C0);
        else
                sh_mmcif_writel(host->addr, MMCIF_CE_INT, 0xD80430C0 | INT_CCS);
        sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, mask);
        /* set arg */
        sh_mmcif_writel(host->addr, MMCIF_CE_ARG, cmd->arg);
        /* set cmd */
        spin_lock_irqsave(&host->lock, flags);
        sh_mmcif_writel(host->addr, MMCIF_CE_CMD_SET, opc);

        host->wait_for = MMCIF_WAIT_FOR_CMD;
        schedule_delayed_work(&host->timeout_work, host->timeout);
        spin_unlock_irqrestore(&host->lock, flags);
}

static void sh_mmcif_stop_cmd(struct sh_mmcif_host *host,
                              struct mmc_request *mrq)
{
        struct device *dev = sh_mmcif_host_to_dev(host);

        switch (mrq->cmd->opcode) {
        case MMC_READ_MULTIPLE_BLOCK:
                sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MCMD12DRE);
                break;
        case MMC_WRITE_MULTIPLE_BLOCK:
                sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MCMD12RBE);
                break;
        default:
                dev_err(dev, "unsupported stop cmd\n");
                mrq->stop->error = sh_mmcif_error_manage(host);
                return;
        }

        host->wait_for = MMCIF_WAIT_FOR_STOP;
}

static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sh_mmcif_host *host = mmc_priv(mmc);
        struct device *dev = sh_mmcif_host_to_dev(host);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);
        if (host->state != STATE_IDLE) {
                dev_dbg(dev, "%s() rejected, state %u\n",
                        __func__, host->state);
                spin_unlock_irqrestore(&host->lock, flags);
                mrq->cmd->error = -EAGAIN;
                mmc_request_done(mmc, mrq);
                return;
        }

        host->state = STATE_REQUEST;
        spin_unlock_irqrestore(&host->lock, flags);

        host->mrq = mrq;

        sh_mmcif_start_cmd(host, mrq);
}

static void sh_mmcif_clk_setup(struct sh_mmcif_host *host)
{
        struct device *dev = sh_mmcif_host_to_dev(host);

        if (host->mmc->f_max) {
                unsigned int f_max, f_min = 0, f_min_old;

                f_max = host->mmc->f_max;
                for (f_min_old = f_max; f_min_old > 2;) {
                        f_min = clk_round_rate(host->clk, f_min_old / 2);
                        if (f_min == f_min_old)
                                break;
                        f_min_old = f_min;
                }

                /*
                 * This driver assumes this SoC is R-Car Gen2 or later
                 */
                host->clkdiv_map = 0x3ff;

                host->mmc->f_max = f_max >> ffs(host->clkdiv_map);
                host->mmc->f_min = f_min >> fls(host->clkdiv_map);
        } else {
                unsigned int clk = clk_get_rate(host->clk);

                host->mmc->f_max = clk / 2;
                host->mmc->f_min = clk / 512;
        }

        dev_dbg(dev, "clk max/min = %d/%d\n",
                host->mmc->f_max, host->mmc->f_min);
}

static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct sh_mmcif_host *host = mmc_priv(mmc);
        struct device *dev = sh_mmcif_host_to_dev(host);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);
        if (host->state != STATE_IDLE) {
                dev_dbg(dev, "%s() rejected, state %u\n",
                        __func__, host->state);
                spin_unlock_irqrestore(&host->lock, flags);
                return;
        }

        host->state = STATE_IOS;
        spin_unlock_irqrestore(&host->lock, flags);

        switch (ios->power_mode) {
        case MMC_POWER_UP:
                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
                if (!host->power) {
                        clk_prepare_enable(host->clk);
                        pm_runtime_get_sync(dev);
                        sh_mmcif_sync_reset(host);
                        sh_mmcif_request_dma(host);
                        host->power = true;
                }
                break;
        case MMC_POWER_OFF:
                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
                if (host->power) {
                        sh_mmcif_clock_control(host, 0);
                        sh_mmcif_release_dma(host);
                        pm_runtime_put(dev);
                        clk_disable_unprepare(host->clk);
                        host->power = false;
                }
                break;
        case MMC_POWER_ON:
                sh_mmcif_clock_control(host, ios->clock);
                break;
        }

        host->timing = ios->timing;
        host->bus_width = ios->bus_width;
        host->state = STATE_IDLE;
}

static const struct mmc_host_ops sh_mmcif_ops = {
        .request        = sh_mmcif_request,
        .set_ios        = sh_mmcif_set_ios,
        .get_cd         = mmc_gpio_get_cd,
};

static bool sh_mmcif_end_cmd(struct sh_mmcif_host *host)
{
        struct mmc_command *cmd = host->mrq->cmd;
        struct mmc_data *data = host->mrq->data;
        struct device *dev = sh_mmcif_host_to_dev(host);
        long time;

        if (host->sd_error) {
                switch (cmd->opcode) {
                case MMC_ALL_SEND_CID:
                case MMC_SELECT_CARD:
                case MMC_APP_CMD:
                        cmd->error = -ETIMEDOUT;
                        break;
                default:
                        cmd->error = sh_mmcif_error_manage(host);
                        break;
                }
                dev_dbg(dev, "CMD%d error %d\n",
                        cmd->opcode, cmd->error);
                host->sd_error = false;
                return false;
        }
        if (!(cmd->flags & MMC_RSP_PRESENT)) {
                cmd->error = 0;
                return false;
        }

        sh_mmcif_get_response(host, cmd);

        if (!data)
                return false;

        /*
         * Completion can be signalled from DMA callback and error, so, have to
         * reset here, before setting .dma_active
         */
        init_completion(&host->dma_complete);

        if (data->flags & MMC_DATA_READ) {
                if (host->chan_rx)
                        sh_mmcif_start_dma_rx(host);
        } else {
                if (host->chan_tx)
                        sh_mmcif_start_dma_tx(host);
        }

        if (!host->dma_active) {
                data->error = sh_mmcif_data_trans(host, host->mrq, cmd->opcode);
                return !data->error;
        }

        /* Running in the IRQ thread, can sleep */
        time = wait_for_completion_interruptible_timeout(&host->dma_complete,
                                                         host->timeout);

        if (data->flags & MMC_DATA_READ)
                dma_unmap_sg(host->chan_rx->device->dev,
                             data->sg, data->sg_len,
                             DMA_FROM_DEVICE);
        else
                dma_unmap_sg(host->chan_tx->device->dev,
                             data->sg, data->sg_len,
                             DMA_TO_DEVICE);

        if (host->sd_error) {
                dev_err(host->mmc->parent,
                        "Error IRQ while waiting for DMA completion!\n");
                /* Woken up by an error IRQ: abort DMA */
                data->error = sh_mmcif_error_manage(host);
        } else if (!time) {
                dev_err(host->mmc->parent, "DMA timeout!\n");
                data->error = -ETIMEDOUT;
        } else if (time < 0) {
                dev_err(host->mmc->parent,
                        "wait_for_completion_...() error %ld!\n", time);
                data->error = time;
        }
        sh_mmcif_bitclr(host, MMCIF_CE_BUF_ACC,
                        BUF_ACC_DMAREN | BUF_ACC_DMAWEN);
        host->dma_active = false;

        if (data->error) {
                data->bytes_xfered = 0;
                /* Abort DMA */
                if (data->flags & MMC_DATA_READ)
                        dmaengine_terminate_sync(host->chan_rx);
                else
                        dmaengine_terminate_sync(host->chan_tx);
        }

        return false;
}

static irqreturn_t sh_mmcif_irqt(int irq, void *dev_id)
{
        struct sh_mmcif_host *host = dev_id;
        struct mmc_request *mrq;
        struct device *dev = sh_mmcif_host_to_dev(host);
        bool wait = false;
        unsigned long flags;
        int wait_work;

        spin_lock_irqsave(&host->lock, flags);
        wait_work = host->wait_for;
        spin_unlock_irqrestore(&host->lock, flags);

        cancel_delayed_work_sync(&host->timeout_work);

        mutex_lock(&host->thread_lock);

        mrq = host->mrq;
        if (!mrq) {
                dev_dbg(dev, "IRQ thread state %u, wait %u: NULL mrq!\n",
                        host->state, host->wait_for);
                mutex_unlock(&host->thread_lock);
                return IRQ_HANDLED;
        }

        /*
         * All handlers return true, if processing continues, and false, if the
         * request has to be completed - successfully or not
         */
        switch (wait_work) {
        case MMCIF_WAIT_FOR_REQUEST:
                /* We're too late, the timeout has already kicked in */
                mutex_unlock(&host->thread_lock);
                return IRQ_HANDLED;
        case MMCIF_WAIT_FOR_CMD:
                /* Wait for data? */
                wait = sh_mmcif_end_cmd(host);
                break;
        case MMCIF_WAIT_FOR_MREAD:
                /* Wait for more data? */
                wait = sh_mmcif_mread_block(host);
                break;
        case MMCIF_WAIT_FOR_READ:
                /* Wait for data end? */
                wait = sh_mmcif_read_block(host);
                break;
        case MMCIF_WAIT_FOR_MWRITE:
                /* Wait data to write? */
                wait = sh_mmcif_mwrite_block(host);
                break;
        case MMCIF_WAIT_FOR_WRITE:
                /* Wait for data end? */
                wait = sh_mmcif_write_block(host);
                break;
        case MMCIF_WAIT_FOR_STOP:
                if (host->sd_error) {
                        mrq->stop->error = sh_mmcif_error_manage(host);
                        dev_dbg(dev, "%s(): %d\n", __func__, mrq->stop->error);
                        break;
                }
                sh_mmcif_get_cmd12response(host, mrq->stop);
                mrq->stop->error = 0;
                break;
        case MMCIF_WAIT_FOR_READ_END:
        case MMCIF_WAIT_FOR_WRITE_END:
                if (host->sd_error) {
                        mrq->data->error = sh_mmcif_error_manage(host);
                        dev_dbg(dev, "%s(): %d\n", __func__, mrq->data->error);
                }
                break;
        default:
                BUG();
        }

        if (wait) {
                schedule_delayed_work(&host->timeout_work, host->timeout);
                /* Wait for more data */
                mutex_unlock(&host->thread_lock);
                return IRQ_HANDLED;
        }

        if (host->wait_for != MMCIF_WAIT_FOR_STOP) {
                struct mmc_data *data = mrq->data;
                if (!mrq->cmd->error && data && !data->error)
                        data->bytes_xfered =
                                data->blocks * data->blksz;

                if (mrq->stop && !mrq->cmd->error && (!data || !data->error)) {
                        sh_mmcif_stop_cmd(host, mrq);
                        if (!mrq->stop->error) {
                                schedule_delayed_work(&host->timeout_work, host->timeout);
                                mutex_unlock(&host->thread_lock);
                                return IRQ_HANDLED;
                        }
                }
        }

        host->wait_for = MMCIF_WAIT_FOR_REQUEST;
        host->state = STATE_IDLE;
        host->mrq = NULL;
        mmc_request_done(host->mmc, mrq);

        mutex_unlock(&host->thread_lock);

        return IRQ_HANDLED;
}

static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
{
        struct sh_mmcif_host *host = dev_id;
        struct device *dev = sh_mmcif_host_to_dev(host);
        u32 state, mask;

        state = sh_mmcif_readl(host->addr, MMCIF_CE_INT);
        mask = sh_mmcif_readl(host->addr, MMCIF_CE_INT_MASK);
        if (host->ccs_enable)
                sh_mmcif_writel(host->addr, MMCIF_CE_INT, ~(state & mask));
        else
                sh_mmcif_writel(host->addr, MMCIF_CE_INT, INT_CCS | ~(state & mask));
        sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state & MASK_CLEAN);

        if (state & ~MASK_CLEAN)
                dev_dbg(dev, "IRQ state = 0x%08x incompletely cleared\n",
                        state);

        if (state & INT_ERR_STS || state & ~INT_ALL) {
                host->sd_error = true;
                dev_dbg(dev, "int err state = 0x%08x\n", state);
        }
        if (state & ~(INT_CMD12RBE | INT_CMD12CRE)) {
                if (!host->mrq)
                        dev_dbg(dev, "NULL IRQ state = 0x%08x\n", state);
                if (!host->dma_active)
                        return IRQ_WAKE_THREAD;
                else if (host->sd_error)
                        sh_mmcif_dma_complete(host);
        } else {
                dev_dbg(dev, "Unexpected IRQ 0x%x\n", state);
        }

        return IRQ_HANDLED;
}

static void sh_mmcif_timeout_work(struct work_struct *work)
{
        struct delayed_work *d = to_delayed_work(work);
        struct sh_mmcif_host *host = container_of(d, struct sh_mmcif_host, timeout_work);
        struct mmc_request *mrq = host->mrq;
        struct device *dev = sh_mmcif_host_to_dev(host);
        unsigned long flags;

        if (host->dying)
                /* Don't run after mmc_remove_host() */
                return;

        spin_lock_irqsave(&host->lock, flags);
        if (host->state == STATE_IDLE) {
                spin_unlock_irqrestore(&host->lock, flags);
                return;
        }

        dev_err(dev, "Timeout waiting for %u on CMD%u\n",
                host->wait_for, mrq->cmd->opcode);

        host->state = STATE_TIMEOUT;
        spin_unlock_irqrestore(&host->lock, flags);

        /*
         * Handle races with cancel_delayed_work(), unless
         * cancel_delayed_work_sync() is used
         */
        switch (host->wait_for) {
        case MMCIF_WAIT_FOR_CMD:
                mrq->cmd->error = sh_mmcif_error_manage(host);
                break;
        case MMCIF_WAIT_FOR_STOP:
                mrq->stop->error = sh_mmcif_error_manage(host);
                break;
        case MMCIF_WAIT_FOR_MREAD:
        case MMCIF_WAIT_FOR_MWRITE:
        case MMCIF_WAIT_FOR_READ:
        case MMCIF_WAIT_FOR_WRITE:
        case MMCIF_WAIT_FOR_READ_END:
        case MMCIF_WAIT_FOR_WRITE_END:
                mrq->data->error = sh_mmcif_error_manage(host);
                break;
        default:
                BUG();
        }

        host->state = STATE_IDLE;
        host->wait_for = MMCIF_WAIT_FOR_REQUEST;
        host->mrq = NULL;
        mmc_request_done(host->mmc, mrq);
}

static void sh_mmcif_init_ocr(struct sh_mmcif_host *host)
{
        struct device *dev = sh_mmcif_host_to_dev(host);
        struct sh_mmcif_plat_data *pd = dev->platform_data;
        struct mmc_host *mmc = host->mmc;

        mmc_regulator_get_supply(mmc);

        if (!pd)
                return;

        if (!mmc->ocr_avail)
                mmc->ocr_avail = pd->ocr;
        else if (pd->ocr)
                dev_warn(mmc_dev(mmc), "Platform OCR mask is ignored\n");
}

static int sh_mmcif_probe(struct platform_device *pdev)
{
        int ret = 0, irq[2];
        struct mmc_host *mmc;
        struct sh_mmcif_host *host;
        struct device *dev = &pdev->dev;
        struct sh_mmcif_plat_data *pd = dev->platform_data;
        void __iomem *reg;
        const char *name;

        irq[0] = platform_get_irq(pdev, 0);
        irq[1] = platform_get_irq_optional(pdev, 1);
        if (irq[0] < 0)
                return irq[0];

        reg = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(reg))
                return PTR_ERR(reg);

        mmc = devm_mmc_alloc_host(dev, sizeof(*host));
        if (!mmc)
                return -ENOMEM;

        ret = mmc_of_parse(mmc);
        if (ret < 0)
                return ret;

        host            = mmc_priv(mmc);
        host->mmc       = mmc;
        host->addr      = reg;
        host->timeout   = msecs_to_jiffies(10000);
        host->ccs_enable = true;
        host->clk_ctrl2_enable = false;

        host->pd = pdev;

        spin_lock_init(&host->lock);

        mmc->ops = &sh_mmcif_ops;
        sh_mmcif_init_ocr(host);

        mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_WAIT_WHILE_BUSY;
        mmc->caps2 |= MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
        mmc->max_busy_timeout = 10000;

        if (pd && pd->caps)
                mmc->caps |= pd->caps;
        mmc->max_segs = 32;
        mmc->max_blk_size = 512;
        mmc->max_req_size = PAGE_SIZE * mmc->max_segs;
        mmc->max_blk_count = mmc->max_req_size / mmc->max_blk_size;
        mmc->max_seg_size = mmc->max_req_size;

        platform_set_drvdata(pdev, host);

        host->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(host->clk))
                return dev_err_probe(dev, PTR_ERR(host->clk),
                                     "cannot get clock\n");

        ret = clk_prepare_enable(host->clk);
        if (ret < 0)
                return ret;

        sh_mmcif_clk_setup(host);

        pm_runtime_enable(dev);
        host->power = false;

        ret = pm_runtime_get_sync(dev);
        if (ret < 0)
                goto err_clk;

        INIT_DELAYED_WORK(&host->timeout_work, sh_mmcif_timeout_work);

        sh_mmcif_sync_reset(host);
        sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);

        name = irq[1] < 0 ? dev_name(dev) : "sh_mmc:error";
        ret = devm_request_threaded_irq(dev, irq[0], sh_mmcif_intr,
                                        sh_mmcif_irqt, 0, name, host);
        if (ret) {
                dev_err(dev, "request_irq error (%s)\n", name);
                goto err_clk;
        }
        if (irq[1] >= 0) {
                ret = devm_request_threaded_irq(dev, irq[1],
                                                sh_mmcif_intr, sh_mmcif_irqt,
                                                0, "sh_mmc:int", host);
                if (ret) {
                        dev_err(dev, "request_irq error (sh_mmc:int)\n");
                        goto err_clk;
                }
        }

        mutex_init(&host->thread_lock);

        ret = mmc_add_host(mmc);
        if (ret < 0)
                goto err_clk;

        dev_pm_qos_expose_latency_limit(dev, 100);

        dev_info(dev, "Chip version 0x%04x, clock rate %luMHz\n",
                 sh_mmcif_readl(host->addr, MMCIF_CE_VERSION) & 0xffff,
                 clk_get_rate(host->clk) / 1000000UL);

        pm_runtime_put(dev);
        clk_disable_unprepare(host->clk);
        return ret;

err_clk:
        clk_disable_unprepare(host->clk);
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);
        return ret;
}

static void sh_mmcif_remove(struct platform_device *pdev)
{
        struct sh_mmcif_host *host = platform_get_drvdata(pdev);

        host->dying = true;
        clk_prepare_enable(host->clk);
        pm_runtime_get_sync(&pdev->dev);

        dev_pm_qos_hide_latency_limit(&pdev->dev);

        mmc_remove_host(host->mmc);
        sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);

        /*
         * FIXME: cancel_delayed_work(_sync)() and free_irq() race with the
         * mmc_remove_host() call above. But swapping order doesn't help either
         * (a query on the linux-mmc mailing list didn't bring any replies).
         */
        cancel_delayed_work_sync(&host->timeout_work);

        clk_disable_unprepare(host->clk);
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
}

static int sh_mmcif_suspend(struct device *dev)
{
        struct sh_mmcif_host *host = dev_get_drvdata(dev);

        pm_runtime_get_sync(dev);
        sh_mmcif_writel(host->addr, MMCIF_CE_INT_MASK, MASK_ALL);
        pm_runtime_put(dev);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(sh_mmcif_dev_pm_ops, sh_mmcif_suspend, NULL);

static struct platform_driver sh_mmcif_driver = {
        .probe          = sh_mmcif_probe,
        .remove         = sh_mmcif_remove,
        .driver         = {
                .name   = DRIVER_NAME,
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .pm     = pm_sleep_ptr(&sh_mmcif_dev_pm_ops),
                .of_match_table = sh_mmcif_of_match,
        },
};

module_platform_driver(sh_mmcif_driver);

MODULE_DESCRIPTION("SuperH on-chip MMC/eMMC interface driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("Yusuke Goda <yusuke.goda.sx@renesas.com>");