/*
 * Synopsys DesignWare Multimedia Card Interface driver
 *  (Based on NXP driver for lpc 31xx)
 *
 * Copyright (C) 2009 NXP Semiconductors
 * Copyright (C) 2009, 2010 Imagination Technologies Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/blkdev.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include <linux/mmc/sdio.h>
#include <linux/bitops.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/mmc/slot-gpio.h>

#include "dw_mmc.h"

/* Common flag combinations */
#define DW_MCI_DATA_ERROR_FLAGS (SDMMC_INT_DRTO | SDMMC_INT_DCRC | \
                                 SDMMC_INT_HTO | SDMMC_INT_SBE  | \
                                 SDMMC_INT_EBE | SDMMC_INT_HLE)
#define DW_MCI_CMD_ERROR_FLAGS  (SDMMC_INT_RTO | SDMMC_INT_RCRC | \
                                 SDMMC_INT_RESP_ERR | SDMMC_INT_HLE)
#define DW_MCI_ERROR_FLAGS      (DW_MCI_DATA_ERROR_FLAGS | \
                                 DW_MCI_CMD_ERROR_FLAGS)
#define DW_MCI_SEND_STATUS      1
#define DW_MCI_RECV_STATUS      2
#define DW_MCI_DMA_THRESHOLD    16

#define DW_MCI_FREQ_MAX 200000000       /* unit: HZ */
#define DW_MCI_FREQ_MIN 100000          /* unit: HZ */

#define IDMAC_INT_CLR           (SDMMC_IDMAC_INT_AI | SDMMC_IDMAC_INT_NI | \
                                 SDMMC_IDMAC_INT_CES | SDMMC_IDMAC_INT_DU | \
                                 SDMMC_IDMAC_INT_FBE | SDMMC_IDMAC_INT_RI | \
                                 SDMMC_IDMAC_INT_TI)

#define DESC_RING_BUF_SZ        PAGE_SIZE

struct idmac_desc_64addr {
        u32             des0;   /* Control Descriptor */
#define IDMAC_OWN_CLR64(x) \
        !((x) & cpu_to_le32(IDMAC_DES0_OWN))

        u32             des1;   /* Reserved */

        u32             des2;   /*Buffer sizes */
#define IDMAC_64ADDR_SET_BUFFER1_SIZE(d, s) \
        ((d)->des2 = ((d)->des2 & cpu_to_le32(0x03ffe000)) | \
         ((cpu_to_le32(s)) & cpu_to_le32(0x1fff)))

        u32             des3;   /* Reserved */

        u32             des4;   /* Lower 32-bits of Buffer Address Pointer 1*/
        u32             des5;   /* Upper 32-bits of Buffer Address Pointer 1*/

        u32             des6;   /* Lower 32-bits of Next Descriptor Address */
        u32             des7;   /* Upper 32-bits of Next Descriptor Address */
};

struct idmac_desc {
        __le32          des0;   /* Control Descriptor */
#define IDMAC_DES0_DIC  BIT(1)
#define IDMAC_DES0_LD   BIT(2)
#define IDMAC_DES0_FD   BIT(3)
#define IDMAC_DES0_CH   BIT(4)
#define IDMAC_DES0_ER   BIT(5)
#define IDMAC_DES0_CES  BIT(30)
#define IDMAC_DES0_OWN  BIT(31)

        __le32          des1;   /* Buffer sizes */
#define IDMAC_SET_BUFFER1_SIZE(d, s) \
        ((d)->des1 = ((d)->des1 & cpu_to_le32(0x03ffe000)) | (cpu_to_le32((s) & 0x1fff)))

        __le32          des2;   /* buffer 1 physical address */

        __le32          des3;   /* buffer 2 physical address */
};

/* Each descriptor can transfer up to 4KB of data in chained mode */
#define DW_MCI_DESC_DATA_LENGTH 0x1000

#if defined(CONFIG_DEBUG_FS)
static int dw_mci_req_show(struct seq_file *s, void *v)
{
        struct dw_mci_slot *slot = s->private;
        struct mmc_request *mrq;
        struct mmc_command *cmd;
        struct mmc_command *stop;
        struct mmc_data *data;

        /* Make sure we get a consistent snapshot */
        spin_lock_bh(&slot->host->lock);
        mrq = slot->mrq;

        if (mrq) {
                cmd = mrq->cmd;
                data = mrq->data;
                stop = mrq->stop;

                if (cmd)
                        seq_printf(s,
                                   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
                                   cmd->opcode, cmd->arg, cmd->flags,
                                   cmd->resp[0], cmd->resp[1], cmd->resp[2],
                                   cmd->resp[2], cmd->error);
                if (data)
                        seq_printf(s, "DATA %u / %u * %u flg %x err %d\n",
                                   data->bytes_xfered, data->blocks,
                                   data->blksz, data->flags, data->error);
                if (stop)
                        seq_printf(s,
                                   "CMD%u(0x%x) flg %x rsp %x %x %x %x err %d\n",
                                   stop->opcode, stop->arg, stop->flags,
                                   stop->resp[0], stop->resp[1], stop->resp[2],
                                   stop->resp[2], stop->error);
        }

        spin_unlock_bh(&slot->host->lock);

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(dw_mci_req);

static int dw_mci_regs_show(struct seq_file *s, void *v)
{
        struct dw_mci *host = s->private;

        pm_runtime_get_sync(host->dev);

        seq_printf(s, "STATUS:\t0x%08x\n", mci_readl(host, STATUS));
        seq_printf(s, "RINTSTS:\t0x%08x\n", mci_readl(host, RINTSTS));
        seq_printf(s, "CMD:\t0x%08x\n", mci_readl(host, CMD));
        seq_printf(s, "CTRL:\t0x%08x\n", mci_readl(host, CTRL));
        seq_printf(s, "INTMASK:\t0x%08x\n", mci_readl(host, INTMASK));
        seq_printf(s, "CLKENA:\t0x%08x\n", mci_readl(host, CLKENA));

        pm_runtime_put_autosuspend(host->dev);

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(dw_mci_regs);

static void dw_mci_init_debugfs(struct dw_mci_slot *slot)
{
        struct mmc_host *mmc = slot->mmc;
        struct dw_mci *host = slot->host;
        struct dentry *root;
        struct dentry *node;

        root = mmc->debugfs_root;
        if (!root)
                return;

        node = debugfs_create_file("regs", S_IRUSR, root, host,
                                   &dw_mci_regs_fops);
        if (!node)
                goto err;

        node = debugfs_create_file("req", S_IRUSR, root, slot,
                                   &dw_mci_req_fops);
        if (!node)
                goto err;

        node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state);
        if (!node)
                goto err;

        node = debugfs_create_x32("pending_events", S_IRUSR, root,
                                  (u32 *)&host->pending_events);
        if (!node)
                goto err;

        node = debugfs_create_x32("completed_events", S_IRUSR, root,
                                  (u32 *)&host->completed_events);
        if (!node)
                goto err;

        return;

err:
        dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n");
}
#endif /* defined(CONFIG_DEBUG_FS) */

static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset)
{
        u32 ctrl;

        ctrl = mci_readl(host, CTRL);
        ctrl |= reset;
        mci_writel(host, CTRL, ctrl);

        /* wait till resets clear */
        if (readl_poll_timeout_atomic(host->regs + SDMMC_CTRL, ctrl,
                                      !(ctrl & reset),
                                      1, 500 * USEC_PER_MSEC)) {
                dev_err(host->dev,
                        "Timeout resetting block (ctrl reset %#x)\n",
                        ctrl & reset);
                return false;
        }

        return true;
}

static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags)
{
        u32 status;

        /*
         * Databook says that before issuing a new data transfer command
         * we need to check to see if the card is busy.  Data transfer commands
         * all have SDMMC_CMD_PRV_DAT_WAIT set, so we'll key off that.
         *
         * ...also allow sending for SDMMC_CMD_VOLT_SWITCH where busy is
         * expected.
         */
        if ((cmd_flags & SDMMC_CMD_PRV_DAT_WAIT) &&
            !(cmd_flags & SDMMC_CMD_VOLT_SWITCH)) {
                if (readl_poll_timeout_atomic(host->regs + SDMMC_STATUS,
                                              status,
                                              !(status & SDMMC_STATUS_BUSY),
                                              10, 500 * USEC_PER_MSEC))
                        dev_err(host->dev, "Busy; trying anyway\n");
        }
}

static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
{
        struct dw_mci *host = slot->host;
        unsigned int cmd_status = 0;

        mci_writel(host, CMDARG, arg);
        wmb(); /* drain writebuffer */
        dw_mci_wait_while_busy(host, cmd);
        mci_writel(host, CMD, SDMMC_CMD_START | cmd);

        if (readl_poll_timeout_atomic(host->regs + SDMMC_CMD, cmd_status,
                                      !(cmd_status & SDMMC_CMD_START),
                                      1, 500 * USEC_PER_MSEC))
                dev_err(&slot->mmc->class_dev,
                        "Timeout sending command (cmd %#x arg %#x status %#x)\n",
                        cmd, arg, cmd_status);
}

static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        u32 cmdr;

        cmd->error = -EINPROGRESS;
        cmdr = cmd->opcode;

        if (cmd->opcode == MMC_STOP_TRANSMISSION ||
            cmd->opcode == MMC_GO_IDLE_STATE ||
            cmd->opcode == MMC_GO_INACTIVE_STATE ||
            (cmd->opcode == SD_IO_RW_DIRECT &&
             ((cmd->arg >> 9) & 0x1FFFF) == SDIO_CCCR_ABORT))
                cmdr |= SDMMC_CMD_STOP;
        else if (cmd->opcode != MMC_SEND_STATUS && cmd->data)
                cmdr |= SDMMC_CMD_PRV_DAT_WAIT;

        if (cmd->opcode == SD_SWITCH_VOLTAGE) {
                u32 clk_en_a;

                /* Special bit makes CMD11 not die */
                cmdr |= SDMMC_CMD_VOLT_SWITCH;

                /* Change state to continue to handle CMD11 weirdness */
                WARN_ON(slot->host->state != STATE_SENDING_CMD);
                slot->host->state = STATE_SENDING_CMD11;

                /*
                 * We need to disable low power mode (automatic clock stop)
                 * while doing voltage switch so we don't confuse the card,
                 * since stopping the clock is a specific part of the UHS
                 * voltage change dance.
                 *
                 * Note that low power mode (SDMMC_CLKEN_LOW_PWR) will be
                 * unconditionally turned back on in dw_mci_setup_bus() if it's
                 * ever called with a non-zero clock.  That shouldn't happen
                 * until the voltage change is all done.
                 */
                clk_en_a = mci_readl(host, CLKENA);
                clk_en_a &= ~(SDMMC_CLKEN_LOW_PWR << slot->id);
                mci_writel(host, CLKENA, clk_en_a);
                mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
                             SDMMC_CMD_PRV_DAT_WAIT, 0);
        }

        if (cmd->flags & MMC_RSP_PRESENT) {
                /* We expect a response, so set this bit */
                cmdr |= SDMMC_CMD_RESP_EXP;
                if (cmd->flags & MMC_RSP_136)
                        cmdr |= SDMMC_CMD_RESP_LONG;
        }

        if (cmd->flags & MMC_RSP_CRC)
                cmdr |= SDMMC_CMD_RESP_CRC;

        if (cmd->data) {
                cmdr |= SDMMC_CMD_DAT_EXP;
                if (cmd->data->flags & MMC_DATA_WRITE)
                        cmdr |= SDMMC_CMD_DAT_WR;
        }

        if (!test_bit(DW_MMC_CARD_NO_USE_HOLD, &slot->flags))
                cmdr |= SDMMC_CMD_USE_HOLD_REG;

        return cmdr;
}

static u32 dw_mci_prep_stop_abort(struct dw_mci *host, struct mmc_command *cmd)
{
        struct mmc_command *stop;
        u32 cmdr;

        if (!cmd->data)
                return 0;

        stop = &host->stop_abort;
        cmdr = cmd->opcode;
        memset(stop, 0, sizeof(struct mmc_command));

        if (cmdr == MMC_READ_SINGLE_BLOCK ||
            cmdr == MMC_READ_MULTIPLE_BLOCK ||
            cmdr == MMC_WRITE_BLOCK ||
            cmdr == MMC_WRITE_MULTIPLE_BLOCK ||
            cmdr == MMC_SEND_TUNING_BLOCK ||
            cmdr == MMC_SEND_TUNING_BLOCK_HS200) {
                stop->opcode = MMC_STOP_TRANSMISSION;
                stop->arg = 0;
                stop->flags = MMC_RSP_R1B | MMC_CMD_AC;
        } else if (cmdr == SD_IO_RW_EXTENDED) {
                stop->opcode = SD_IO_RW_DIRECT;
                stop->arg |= (1 << 31) | (0 << 28) | (SDIO_CCCR_ABORT << 9) |
                             ((cmd->arg >> 28) & 0x7);
                stop->flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_AC;
        } else {
                return 0;
        }

        cmdr = stop->opcode | SDMMC_CMD_STOP |
                SDMMC_CMD_RESP_CRC | SDMMC_CMD_RESP_EXP;

        if (!test_bit(DW_MMC_CARD_NO_USE_HOLD, &host->slot->flags))
                cmdr |= SDMMC_CMD_USE_HOLD_REG;

        return cmdr;
}

static inline void dw_mci_set_cto(struct dw_mci *host)
{
        unsigned int cto_clks;
        unsigned int cto_div;
        unsigned int cto_ms;
        unsigned long irqflags;

        cto_clks = mci_readl(host, TMOUT) & 0xff;
        cto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
        if (cto_div == 0)
                cto_div = 1;

        cto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * cto_clks * cto_div,
                                  host->bus_hz);

        /* add a bit spare time */
        cto_ms += 10;

        /*
         * The durations we're working with are fairly short so we have to be
         * extra careful about synchronization here.  Specifically in hardware a
         * command timeout is _at most_ 5.1 ms, so that means we expect an
         * interrupt (either command done or timeout) to come rather quickly
         * after the mci_writel.  ...but just in case we have a long interrupt
         * latency let's add a bit of paranoia.
         *
         * In general we'll assume that at least an interrupt will be asserted
         * in hardware by the time the cto_timer runs.  ...and if it hasn't
         * been asserted in hardware by that time then we'll assume it'll never
         * come.
         */
        spin_lock_irqsave(&host->irq_lock, irqflags);
        if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
                mod_timer(&host->cto_timer,
                        jiffies + msecs_to_jiffies(cto_ms) + 1);
        spin_unlock_irqrestore(&host->irq_lock, irqflags);
}

static void dw_mci_start_command(struct dw_mci *host,
                                 struct mmc_command *cmd, u32 cmd_flags)
{
        host->cmd = cmd;
        dev_vdbg(host->dev,
                 "start command: ARGR=0x%08x CMDR=0x%08x\n",
                 cmd->arg, cmd_flags);

        mci_writel(host, CMDARG, cmd->arg);
        wmb(); /* drain writebuffer */
        dw_mci_wait_while_busy(host, cmd_flags);

        mci_writel(host, CMD, cmd_flags | SDMMC_CMD_START);

        /* response expected command only */
        if (cmd_flags & SDMMC_CMD_RESP_EXP)
                dw_mci_set_cto(host);
}

static inline void send_stop_abort(struct dw_mci *host, struct mmc_data *data)
{
        struct mmc_command *stop = &host->stop_abort;

        dw_mci_start_command(host, stop, host->stop_cmdr);
}

/* DMA interface functions */
static void dw_mci_stop_dma(struct dw_mci *host)
{
        if (host->using_dma) {
                host->dma_ops->stop(host);
                host->dma_ops->cleanup(host);
        }

        /* Data transfer was stopped by the interrupt handler */
        set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
}

static void dw_mci_dma_cleanup(struct dw_mci *host)
{
        struct mmc_data *data = host->data;

        if (data && data->host_cookie == COOKIE_MAPPED) {
                dma_unmap_sg(host->dev,
                             data->sg,
                             data->sg_len,
                             mmc_get_dma_dir(data));
                data->host_cookie = COOKIE_UNMAPPED;
        }
}

static void dw_mci_idmac_reset(struct dw_mci *host)
{
        u32 bmod = mci_readl(host, BMOD);
        /* Software reset of DMA */
        bmod |= SDMMC_IDMAC_SWRESET;
        mci_writel(host, BMOD, bmod);
}

static void dw_mci_idmac_stop_dma(struct dw_mci *host)
{
        u32 temp;

        /* Disable and reset the IDMAC interface */
        temp = mci_readl(host, CTRL);
        temp &= ~SDMMC_CTRL_USE_IDMAC;
        temp |= SDMMC_CTRL_DMA_RESET;
        mci_writel(host, CTRL, temp);

        /* Stop the IDMAC running */
        temp = mci_readl(host, BMOD);
        temp &= ~(SDMMC_IDMAC_ENABLE | SDMMC_IDMAC_FB);
        temp |= SDMMC_IDMAC_SWRESET;
        mci_writel(host, BMOD, temp);
}

static void dw_mci_dmac_complete_dma(void *arg)
{
        struct dw_mci *host = arg;
        struct mmc_data *data = host->data;

        dev_vdbg(host->dev, "DMA complete\n");

        if ((host->use_dma == TRANS_MODE_EDMAC) &&
            data && (data->flags & MMC_DATA_READ))
                /* Invalidate cache after read */
                dma_sync_sg_for_cpu(mmc_dev(host->slot->mmc),
                                    data->sg,
                                    data->sg_len,
                                    DMA_FROM_DEVICE);

        host->dma_ops->cleanup(host);

        /*
         * If the card was removed, data will be NULL. No point in trying to
         * send the stop command or waiting for NBUSY in this case.
         */
        if (data) {
                set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
                tasklet_schedule(&host->tasklet);
        }
}

static int dw_mci_idmac_init(struct dw_mci *host)
{
        int i;

        if (host->dma_64bit_address == 1) {
                struct idmac_desc_64addr *p;
                /* Number of descriptors in the ring buffer */
                host->ring_size =
                        DESC_RING_BUF_SZ / sizeof(struct idmac_desc_64addr);

                /* Forward link the descriptor list */
                for (i = 0, p = host->sg_cpu; i < host->ring_size - 1;
                                                                i++, p++) {
                        p->des6 = (host->sg_dma +
                                        (sizeof(struct idmac_desc_64addr) *
                                                        (i + 1))) & 0xffffffff;

                        p->des7 = (u64)(host->sg_dma +
                                        (sizeof(struct idmac_desc_64addr) *
                                                        (i + 1))) >> 32;
                        /* Initialize reserved and buffer size fields to "0" */
                        p->des0 = 0;
                        p->des1 = 0;
                        p->des2 = 0;
                        p->des3 = 0;
                }

                /* Set the last descriptor as the end-of-ring descriptor */
                p->des6 = host->sg_dma & 0xffffffff;
                p->des7 = (u64)host->sg_dma >> 32;
                p->des0 = IDMAC_DES0_ER;

        } else {
                struct idmac_desc *p;
                /* Number of descriptors in the ring buffer */
                host->ring_size =
                        DESC_RING_BUF_SZ / sizeof(struct idmac_desc);

                /* Forward link the descriptor list */
                for (i = 0, p = host->sg_cpu;
                     i < host->ring_size - 1;
                     i++, p++) {
                        p->des3 = cpu_to_le32(host->sg_dma +
                                        (sizeof(struct idmac_desc) * (i + 1)));
                        p->des0 = 0;
                        p->des1 = 0;
                }

                /* Set the last descriptor as the end-of-ring descriptor */
                p->des3 = cpu_to_le32(host->sg_dma);
                p->des0 = cpu_to_le32(IDMAC_DES0_ER);
        }

        dw_mci_idmac_reset(host);

        if (host->dma_64bit_address == 1) {
                /* Mask out interrupts - get Tx & Rx complete only */
                mci_writel(host, IDSTS64, IDMAC_INT_CLR);
                mci_writel(host, IDINTEN64, SDMMC_IDMAC_INT_NI |
                                SDMMC_IDMAC_INT_RI | SDMMC_IDMAC_INT_TI);

                /* Set the descriptor base address */
                mci_writel(host, DBADDRL, host->sg_dma & 0xffffffff);
                mci_writel(host, DBADDRU, (u64)host->sg_dma >> 32);

        } else {
                /* Mask out interrupts - get Tx & Rx complete only */
                mci_writel(host, IDSTS, IDMAC_INT_CLR);
                mci_writel(host, IDINTEN, SDMMC_IDMAC_INT_NI |
                                SDMMC_IDMAC_INT_RI | SDMMC_IDMAC_INT_TI);

                /* Set the descriptor base address */
                mci_writel(host, DBADDR, host->sg_dma);
        }

        return 0;
}

static inline int dw_mci_prepare_desc64(struct dw_mci *host,
                                         struct mmc_data *data,
                                         unsigned int sg_len)
{
        unsigned int desc_len;
        struct idmac_desc_64addr *desc_first, *desc_last, *desc;
        u32 val;
        int i;

        desc_first = desc_last = desc = host->sg_cpu;

        for (i = 0; i < sg_len; i++) {
                unsigned int length = sg_dma_len(&data->sg[i]);

                u64 mem_addr = sg_dma_address(&data->sg[i]);

                for ( ; length ; desc++) {
                        desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
                                   length : DW_MCI_DESC_DATA_LENGTH;

                        length -= desc_len;

                        /*
                         * Wait for the former clear OWN bit operation
                         * of IDMAC to make sure that this descriptor
                         * isn't still owned by IDMAC as IDMAC's write
                         * ops and CPU's read ops are asynchronous.
                         */
                        if (readl_poll_timeout_atomic(&desc->des0, val,
                                                !(val & IDMAC_DES0_OWN),
                                                10, 100 * USEC_PER_MSEC))
                                goto err_own_bit;

                        /*
                         * Set the OWN bit and disable interrupts
                         * for this descriptor
                         */
                        desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
                                                IDMAC_DES0_CH;

                        /* Buffer length */
                        IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, desc_len);

                        /* Physical address to DMA to/from */
                        desc->des4 = mem_addr & 0xffffffff;
                        desc->des5 = mem_addr >> 32;

                        /* Update physical address for the next desc */
                        mem_addr += desc_len;

                        /* Save pointer to the last descriptor */
                        desc_last = desc;
                }
        }

        /* Set first descriptor */
        desc_first->des0 |= IDMAC_DES0_FD;

        /* Set last descriptor */
        desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
        desc_last->des0 |= IDMAC_DES0_LD;

        return 0;
err_own_bit:
        /* restore the descriptor chain as it's polluted */
        dev_dbg(host->dev, "descriptor is still owned by IDMAC.\n");
        memset(host->sg_cpu, 0, DESC_RING_BUF_SZ);
        dw_mci_idmac_init(host);
        return -EINVAL;
}


static inline int dw_mci_prepare_desc32(struct dw_mci *host,
                                         struct mmc_data *data,
                                         unsigned int sg_len)
{
        unsigned int desc_len;
        struct idmac_desc *desc_first, *desc_last, *desc;
        u32 val;
        int i;

        desc_first = desc_last = desc = host->sg_cpu;

        for (i = 0; i < sg_len; i++) {
                unsigned int length = sg_dma_len(&data->sg[i]);

                u32 mem_addr = sg_dma_address(&data->sg[i]);

                for ( ; length ; desc++) {
                        desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
                                   length : DW_MCI_DESC_DATA_LENGTH;

                        length -= desc_len;

                        /*
                         * Wait for the former clear OWN bit operation
                         * of IDMAC to make sure that this descriptor
                         * isn't still owned by IDMAC as IDMAC's write
                         * ops and CPU's read ops are asynchronous.
                         */
                        if (readl_poll_timeout_atomic(&desc->des0, val,
                                                      IDMAC_OWN_CLR64(val),
                                                      10,
                                                      100 * USEC_PER_MSEC))
                                goto err_own_bit;

                        /*
                         * Set the OWN bit and disable interrupts
                         * for this descriptor
                         */
                        desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
                                                 IDMAC_DES0_DIC |
                                                 IDMAC_DES0_CH);

                        /* Buffer length */
                        IDMAC_SET_BUFFER1_SIZE(desc, desc_len);

                        /* Physical address to DMA to/from */
                        desc->des2 = cpu_to_le32(mem_addr);

                        /* Update physical address for the next desc */
                        mem_addr += desc_len;

                        /* Save pointer to the last descriptor */
                        desc_last = desc;
                }
        }

        /* Set first descriptor */
        desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);

        /* Set last descriptor */
        desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
                                       IDMAC_DES0_DIC));
        desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);

        return 0;
err_own_bit:
        /* restore the descriptor chain as it's polluted */
        dev_dbg(host->dev, "descriptor is still owned by IDMAC.\n");
        memset(host->sg_cpu, 0, DESC_RING_BUF_SZ);
        dw_mci_idmac_init(host);
        return -EINVAL;
}

static int dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
{
        u32 temp;
        int ret;

        if (host->dma_64bit_address == 1)
                ret = dw_mci_prepare_desc64(host, host->data, sg_len);
        else
                ret = dw_mci_prepare_desc32(host, host->data, sg_len);

        if (ret)
                goto out;

        /* drain writebuffer */
        wmb();

        /* Make sure to reset DMA in case we did PIO before this */
        dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET);
        dw_mci_idmac_reset(host);

        /* Select IDMAC interface */
        temp = mci_readl(host, CTRL);
        temp |= SDMMC_CTRL_USE_IDMAC;
        mci_writel(host, CTRL, temp);

        /* drain writebuffer */
        wmb();

        /* Enable the IDMAC */
        temp = mci_readl(host, BMOD);
        temp |= SDMMC_IDMAC_ENABLE | SDMMC_IDMAC_FB;
        mci_writel(host, BMOD, temp);

        /* Start it running */
        mci_writel(host, PLDMND, 1);

out:
        return ret;
}

static const struct dw_mci_dma_ops dw_mci_idmac_ops = {
        .init = dw_mci_idmac_init,
        .start = dw_mci_idmac_start_dma,
        .stop = dw_mci_idmac_stop_dma,
        .complete = dw_mci_dmac_complete_dma,
        .cleanup = dw_mci_dma_cleanup,
};

static void dw_mci_edmac_stop_dma(struct dw_mci *host)
{
        dmaengine_terminate_async(host->dms->ch);
}

static int dw_mci_edmac_start_dma(struct dw_mci *host,
                                            unsigned int sg_len)
{
        struct dma_slave_config cfg;
        struct dma_async_tx_descriptor *desc = NULL;
        struct scatterlist *sgl = host->data->sg;
        static const u32 mszs[] = {1, 4, 8, 16, 32, 64, 128, 256};
        u32 sg_elems = host->data->sg_len;
        u32 fifoth_val;
        u32 fifo_offset = host->fifo_reg - host->regs;
        int ret = 0;

        /* Set external dma config: burst size, burst width */
        cfg.dst_addr = host->phy_regs + fifo_offset;
        cfg.src_addr = cfg.dst_addr;
        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

        /* Match burst msize with external dma config */
        fifoth_val = mci_readl(host, FIFOTH);
        cfg.dst_maxburst = mszs[(fifoth_val >> 28) & 0x7];
        cfg.src_maxburst = cfg.dst_maxburst;

        if (host->data->flags & MMC_DATA_WRITE)
                cfg.direction = DMA_MEM_TO_DEV;
        else
                cfg.direction = DMA_DEV_TO_MEM;

        ret = dmaengine_slave_config(host->dms->ch, &cfg);
        if (ret) {
                dev_err(host->dev, "Failed to config edmac.\n");
                return -EBUSY;
        }

        desc = dmaengine_prep_slave_sg(host->dms->ch, sgl,
                                       sg_len, cfg.direction,
                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!desc) {
                dev_err(host->dev, "Can't prepare slave sg.\n");
                return -EBUSY;
        }

        /* Set dw_mci_dmac_complete_dma as callback */
        desc->callback = dw_mci_dmac_complete_dma;
        desc->callback_param = (void *)host;
        dmaengine_submit(desc);

        /* Flush cache before write */
        if (host->data->flags & MMC_DATA_WRITE)
                dma_sync_sg_for_device(mmc_dev(host->slot->mmc), sgl,
                                       sg_elems, DMA_TO_DEVICE);

        dma_async_issue_pending(host->dms->ch);

        return 0;
}

static int dw_mci_edmac_init(struct dw_mci *host)
{
        /* Request external dma channel */
        host->dms = kzalloc(sizeof(struct dw_mci_dma_slave), GFP_KERNEL);
        if (!host->dms)
                return -ENOMEM;

        host->dms->ch = dma_request_slave_channel(host->dev, "rx-tx");
        if (!host->dms->ch) {
                dev_err(host->dev, "Failed to get external DMA channel.\n");
                kfree(host->dms);
                host->dms = NULL;
                return -ENXIO;
        }

        return 0;
}

static void dw_mci_edmac_exit(struct dw_mci *host)
{
        if (host->dms) {
                if (host->dms->ch) {
                        dma_release_channel(host->dms->ch);
                        host->dms->ch = NULL;
                }
                kfree(host->dms);
                host->dms = NULL;
        }
}

static const struct dw_mci_dma_ops dw_mci_edmac_ops = {
        .init = dw_mci_edmac_init,
        .exit = dw_mci_edmac_exit,
        .start = dw_mci_edmac_start_dma,
        .stop = dw_mci_edmac_stop_dma,
        .complete = dw_mci_dmac_complete_dma,
        .cleanup = dw_mci_dma_cleanup,
};

static int dw_mci_pre_dma_transfer(struct dw_mci *host,
                                   struct mmc_data *data,
                                   int cookie)
{
        struct scatterlist *sg;
        unsigned int i, sg_len;

        if (data->host_cookie == COOKIE_PRE_MAPPED)
                return data->sg_len;

        /*
         * We don't do DMA on "complex" transfers, i.e. with
         * non-word-aligned buffers or lengths. Also, we don't bother
         * with all the DMA setup overhead for short transfers.
         */
        if (data->blocks * data->blksz < DW_MCI_DMA_THRESHOLD)
                return -EINVAL;

        if (data->blksz & 3)
                return -EINVAL;

        for_each_sg(data->sg, sg, data->sg_len, i) {
                if (sg->offset & 3 || sg->length & 3)
                        return -EINVAL;
        }

        sg_len = dma_map_sg(host->dev,
                            data->sg,
                            data->sg_len,
                            mmc_get_dma_dir(data));
        if (sg_len == 0)
                return -EINVAL;

        data->host_cookie = cookie;

        return sg_len;
}

static void dw_mci_pre_req(struct mmc_host *mmc,
                           struct mmc_request *mrq)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!slot->host->use_dma || !data)
                return;

        /* This data might be unmapped at this time */
        data->host_cookie = COOKIE_UNMAPPED;

        if (dw_mci_pre_dma_transfer(slot->host, mrq->data,
                                COOKIE_PRE_MAPPED) < 0)
                data->host_cookie = COOKIE_UNMAPPED;
}

static void dw_mci_post_req(struct mmc_host *mmc,
                            struct mmc_request *mrq,
                            int err)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!slot->host->use_dma || !data)
                return;

        if (data->host_cookie != COOKIE_UNMAPPED)
                dma_unmap_sg(slot->host->dev,
                             data->sg,
                             data->sg_len,
                             mmc_get_dma_dir(data));
        data->host_cookie = COOKIE_UNMAPPED;
}

static int dw_mci_get_cd(struct mmc_host *mmc)
{
        int present;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        int gpio_cd = mmc_gpio_get_cd(mmc);

        /* Use platform get_cd function, else try onboard card detect */
        if (((mmc->caps & MMC_CAP_NEEDS_POLL)
                                || !mmc_card_is_removable(mmc))) {
                present = 1;

                if (!test_bit(DW_MMC_CARD_PRESENT, &slot->flags)) {
                        if (mmc->caps & MMC_CAP_NEEDS_POLL) {
                                dev_info(&mmc->class_dev,
                                        "card is polling.\n");
                        } else {
                                dev_info(&mmc->class_dev,
                                        "card is non-removable.\n");
                        }
                        set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
                }

                return present;
        } else if (gpio_cd >= 0)
                present = gpio_cd;
        else
                present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
                        == 0 ? 1 : 0;

        spin_lock_bh(&host->lock);
        if (present && !test_and_set_bit(DW_MMC_CARD_PRESENT, &slot->flags))
                dev_dbg(&mmc->class_dev, "card is present\n");
        else if (!present &&

                        !test_and_clear_bit(DW_MMC_CARD_PRESENT, &slot->flags))
                dev_dbg(&mmc->class_dev, "card is not present\n");
        spin_unlock_bh(&host->lock);

        return present;
}

static void dw_mci_adjust_fifoth(struct dw_mci *host, struct mmc_data *data)
{
        unsigned int blksz = data->blksz;
        static const u32 mszs[] = {1, 4, 8, 16, 32, 64, 128, 256};
        u32 fifo_width = 1 << host->data_shift;
        u32 blksz_depth = blksz / fifo_width, fifoth_val;
        u32 msize = 0, rx_wmark = 1, tx_wmark, tx_wmark_invers;
        int idx = ARRAY_SIZE(mszs) - 1;

        /* pio should ship this scenario */
        if (!host->use_dma)
                return;

        tx_wmark = (host->fifo_depth) / 2;
        tx_wmark_invers = host->fifo_depth - tx_wmark;

        /*
         * MSIZE is '1',
         * if blksz is not a multiple of the FIFO width
         */
        if (blksz % fifo_width)
                goto done;

        do {
                if (!((blksz_depth % mszs[idx]) ||
                     (tx_wmark_invers % mszs[idx]))) {
                        msize = idx;
                        rx_wmark = mszs[idx] - 1;
                        break;
                }
        } while (--idx > 0);
        /*
         * If idx is '0', it won't be tried
         * Thus, initial values are uesed
         */
done:
        fifoth_val = SDMMC_SET_FIFOTH(msize, rx_wmark, tx_wmark);
        mci_writel(host, FIFOTH, fifoth_val);
}

static void dw_mci_ctrl_thld(struct dw_mci *host, struct mmc_data *data)
{
        unsigned int blksz = data->blksz;
        u32 blksz_depth, fifo_depth;
        u16 thld_size;
        u8 enable;

        /*
         * CDTHRCTL doesn't exist prior to 240A (in fact that register offset is
         * in the FIFO region, so we really shouldn't access it).
         */
        if (host->verid < DW_MMC_240A ||
                (host->verid < DW_MMC_280A && data->flags & MMC_DATA_WRITE))
                return;

        /*
         * Card write Threshold is introduced since 2.80a
         * It's used when HS400 mode is enabled.
         */
        if (data->flags & MMC_DATA_WRITE &&
                host->timing != MMC_TIMING_MMC_HS400)
                goto disable;

        if (data->flags & MMC_DATA_WRITE)
                enable = SDMMC_CARD_WR_THR_EN;
        else
                enable = SDMMC_CARD_RD_THR_EN;

        if (host->timing != MMC_TIMING_MMC_HS200 &&
            host->timing != MMC_TIMING_UHS_SDR104 &&
            host->timing != MMC_TIMING_MMC_HS400)
                goto disable;

        blksz_depth = blksz / (1 << host->data_shift);
        fifo_depth = host->fifo_depth;

        if (blksz_depth > fifo_depth)
                goto disable;

        /*
         * If (blksz_depth) >= (fifo_depth >> 1), should be 'thld_size <= blksz'
         * If (blksz_depth) <  (fifo_depth >> 1), should be thld_size = blksz
         * Currently just choose blksz.
         */
        thld_size = blksz;
        mci_writel(host, CDTHRCTL, SDMMC_SET_THLD(thld_size, enable));
        return;

disable:
        mci_writel(host, CDTHRCTL, 0);
}

static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
{
        unsigned long irqflags;
        int sg_len;
        u32 temp;

        host->using_dma = 0;

        /* If we don't have a channel, we can't do DMA */
        if (!host->use_dma)
                return -ENODEV;

        sg_len = dw_mci_pre_dma_transfer(host, data, COOKIE_MAPPED);
        if (sg_len < 0) {
                host->dma_ops->stop(host);
                return sg_len;
        }

        host->using_dma = 1;

        if (host->use_dma == TRANS_MODE_IDMAC)
                dev_vdbg(host->dev,
                         "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
                         (unsigned long)host->sg_cpu,
                         (unsigned long)host->sg_dma,
                         sg_len);

        /*
         * Decide the MSIZE and RX/TX Watermark.
         * If current block size is same with previous size,
         * no need to update fifoth.
         */
        if (host->prev_blksz != data->blksz)
                dw_mci_adjust_fifoth(host, data);

        /* Enable the DMA interface */
        temp = mci_readl(host, CTRL);
        temp |= SDMMC_CTRL_DMA_ENABLE;
        mci_writel(host, CTRL, temp);

        /* Disable RX/TX IRQs, let DMA handle it */
        spin_lock_irqsave(&host->irq_lock, irqflags);
        temp = mci_readl(host, INTMASK);
        temp  &= ~(SDMMC_INT_RXDR | SDMMC_INT_TXDR);
        mci_writel(host, INTMASK, temp);
        spin_unlock_irqrestore(&host->irq_lock, irqflags);

        if (host->dma_ops->start(host, sg_len)) {
                host->dma_ops->stop(host);
                /* We can't do DMA, try PIO for this one */
                dev_dbg(host->dev,
                        "%s: fall back to PIO mode for current transfer\n",
                        __func__);
                return -ENODEV;
        }

        return 0;
}

static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data)
{
        unsigned long irqflags;
        int flags = SG_MITER_ATOMIC;
        u32 temp;

        data->error = -EINPROGRESS;

        WARN_ON(host->data);
        host->sg = NULL;
        host->data = data;

        if (data->flags & MMC_DATA_READ)
                host->dir_status = DW_MCI_RECV_STATUS;
        else
                host->dir_status = DW_MCI_SEND_STATUS;

        dw_mci_ctrl_thld(host, data);

        if (dw_mci_submit_data_dma(host, data)) {
                if (host->data->flags & MMC_DATA_READ)
                        flags |= SG_MITER_TO_SG;
                else
                        flags |= SG_MITER_FROM_SG;

                sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
                host->sg = data->sg;
                host->part_buf_start = 0;
                host->part_buf_count = 0;

                mci_writel(host, RINTSTS, SDMMC_INT_TXDR | SDMMC_INT_RXDR);

                spin_lock_irqsave(&host->irq_lock, irqflags);
                temp = mci_readl(host, INTMASK);
                temp |= SDMMC_INT_TXDR | SDMMC_INT_RXDR;
                mci_writel(host, INTMASK, temp);
                spin_unlock_irqrestore(&host->irq_lock, irqflags);

                temp = mci_readl(host, CTRL);
                temp &= ~SDMMC_CTRL_DMA_ENABLE;
                mci_writel(host, CTRL, temp);

                /*
                 * Use the initial fifoth_val for PIO mode. If wm_algined
                 * is set, we set watermark same as data size.
                 * If next issued data may be transfered by DMA mode,
                 * prev_blksz should be invalidated.
                 */
                if (host->wm_aligned)
                        dw_mci_adjust_fifoth(host, data);
                else
                        mci_writel(host, FIFOTH, host->fifoth_val);
                host->prev_blksz = 0;
        } else {
                /*
                 * Keep the current block size.
                 * It will be used to decide whether to update
                 * fifoth register next time.
                 */
                host->prev_blksz = data->blksz;
        }
}

static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
{
        struct dw_mci *host = slot->host;
        unsigned int clock = slot->clock;
        u32 div;
        u32 clk_en_a;
        u32 sdmmc_cmd_bits = SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT;

        /* We must continue to set bit 28 in CMD until the change is complete */
        if (host->state == STATE_WAITING_CMD11_DONE)
                sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH;

        slot->mmc->actual_clock = 0;

        if (!clock) {
                mci_writel(host, CLKENA, 0);
                mci_send_cmd(slot, sdmmc_cmd_bits, 0);
        } else if (clock != host->current_speed || force_clkinit) {
                div = host->bus_hz / clock;
                if (host->bus_hz % clock && host->bus_hz > clock)
                        /*
                         * move the + 1 after the divide to prevent
                         * over-clocking the card.
                         */
                        div += 1;

                div = (host->bus_hz != clock) ? DIV_ROUND_UP(div, 2) : 0;

                if ((clock != slot->__clk_old &&
                        !test_bit(DW_MMC_CARD_NEEDS_POLL, &slot->flags)) ||
                        force_clkinit) {
                        /* Silent the verbose log if calling from PM context */
                        if (!force_clkinit)
                                dev_info(&slot->mmc->class_dev,
                                         "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n",
                                         slot->id, host->bus_hz, clock,
                                         div ? ((host->bus_hz / div) >> 1) :
                                         host->bus_hz, div);

                        /*
                         * If card is polling, display the message only
                         * one time at boot time.
                         */
                        if (slot->mmc->caps & MMC_CAP_NEEDS_POLL &&
                                        slot->mmc->f_min == clock)
                                set_bit(DW_MMC_CARD_NEEDS_POLL, &slot->flags);
                }

                /* disable clock */
                mci_writel(host, CLKENA, 0);
                mci_writel(host, CLKSRC, 0);

                /* inform CIU */
                mci_send_cmd(slot, sdmmc_cmd_bits, 0);

                /* set clock to desired speed */
                mci_writel(host, CLKDIV, div);

                /* inform CIU */
                mci_send_cmd(slot, sdmmc_cmd_bits, 0);

                /* enable clock; only low power if no SDIO */
                clk_en_a = SDMMC_CLKEN_ENABLE << slot->id;
                if (!test_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags))
                        clk_en_a |= SDMMC_CLKEN_LOW_PWR << slot->id;
                mci_writel(host, CLKENA, clk_en_a);

                /* inform CIU */
                mci_send_cmd(slot, sdmmc_cmd_bits, 0);

                /* keep the last clock value that was requested from core */
                slot->__clk_old = clock;
                slot->mmc->actual_clock = div ? ((host->bus_hz / div) >> 1) :
                                          host->bus_hz;
        }

        host->current_speed = clock;

        /* Set the current slot bus width */
        mci_writel(host, CTYPE, (slot->ctype << slot->id));
}

static void __dw_mci_start_request(struct dw_mci *host,
                                   struct dw_mci_slot *slot,
                                   struct mmc_command *cmd)
{
        struct mmc_request *mrq;
        struct mmc_data *data;
        u32 cmdflags;

        mrq = slot->mrq;

        host->mrq = mrq;

        host->pending_events = 0;
        host->completed_events = 0;
        host->cmd_status = 0;
        host->data_status = 0;
        host->dir_status = 0;

        data = cmd->data;
        if (data) {
                mci_writel(host, TMOUT, 0xFFFFFFFF);
                mci_writel(host, BYTCNT, data->blksz*data->blocks);
                mci_writel(host, BLKSIZ, data->blksz);
        }

        cmdflags = dw_mci_prepare_command(slot->mmc, cmd);

        /* this is the first command, send the initialization clock */
        if (test_and_clear_bit(DW_MMC_CARD_NEED_INIT, &slot->flags))
                cmdflags |= SDMMC_CMD_INIT;

        if (data) {
                dw_mci_submit_data(host, data);
                wmb(); /* drain writebuffer */
        }

        dw_mci_start_command(host, cmd, cmdflags);

        if (cmd->opcode == SD_SWITCH_VOLTAGE) {
                unsigned long irqflags;

                /*
                 * Databook says to fail after 2ms w/ no response, but evidence
                 * shows that sometimes the cmd11 interrupt takes over 130ms.
                 * We'll set to 500ms, plus an extra jiffy just in case jiffies
                 * is just about to roll over.
                 *
                 * We do this whole thing under spinlock and only if the
                 * command hasn't already completed (indicating the the irq
                 * already ran so we don't want the timeout).
                 */
                spin_lock_irqsave(&host->irq_lock, irqflags);
                if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
                        mod_timer(&host->cmd11_timer,
                                jiffies + msecs_to_jiffies(500) + 1);
                spin_unlock_irqrestore(&host->irq_lock, irqflags);
        }

        host->stop_cmdr = dw_mci_prep_stop_abort(host, cmd);
}

static void dw_mci_start_request(struct dw_mci *host,
                                 struct dw_mci_slot *slot)
{
        struct mmc_request *mrq = slot->mrq;
        struct mmc_command *cmd;

        cmd = mrq->sbc ? mrq->sbc : mrq->cmd;
        __dw_mci_start_request(host, slot, cmd);
}

/* must be called with host->lock held */
static void dw_mci_queue_request(struct dw_mci *host, struct dw_mci_slot *slot,
                                 struct mmc_request *mrq)
{
        dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n",
                 host->state);

        slot->mrq = mrq;

        if (host->state == STATE_WAITING_CMD11_DONE) {
                dev_warn(&slot->mmc->class_dev,
                         "Voltage change didn't complete\n");
                /*
                 * this case isn't expected to happen, so we can
                 * either crash here or just try to continue on
                 * in the closest possible state
                 */
                host->state = STATE_IDLE;
        }

        if (host->state == STATE_IDLE) {
                host->state = STATE_SENDING_CMD;
                dw_mci_start_request(host, slot);
        } else {
                list_add_tail(&slot->queue_node, &host->queue);
        }
}

static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;

        WARN_ON(slot->mrq);

        /*
         * The check for card presence and queueing of the request must be
         * atomic, otherwise the card could be removed in between and the
         * request wouldn't fail until another card was inserted.
         */

        if (!dw_mci_get_cd(mmc)) {
                mrq->cmd->error = -ENOMEDIUM;
                mmc_request_done(mmc, mrq);
                return;
        }

        spin_lock_bh(&host->lock);

        dw_mci_queue_request(host, slot, mrq);

        spin_unlock_bh(&host->lock);
}

static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        const struct dw_mci_drv_data *drv_data = slot->host->drv_data;
        u32 regs;
        int ret;

        switch (ios->bus_width) {
        case MMC_BUS_WIDTH_4:
                slot->ctype = SDMMC_CTYPE_4BIT;
                break;
        case MMC_BUS_WIDTH_8:
                slot->ctype = SDMMC_CTYPE_8BIT;
                break;
        default:
                /* set default 1 bit mode */
                slot->ctype = SDMMC_CTYPE_1BIT;
        }

        regs = mci_readl(slot->host, UHS_REG);

        /* DDR mode set */
        if (ios->timing == MMC_TIMING_MMC_DDR52 ||
            ios->timing == MMC_TIMING_UHS_DDR50 ||
            ios->timing == MMC_TIMING_MMC_HS400)
                regs |= ((0x1 << slot->id) << 16);
        else
                regs &= ~((0x1 << slot->id) << 16);

        mci_writel(slot->host, UHS_REG, regs);
        slot->host->timing = ios->timing;

        /*
         * Use mirror of ios->clock to prevent race with mmc
         * core ios update when finding the minimum.
         */
        slot->clock = ios->clock;

        if (drv_data && drv_data->set_ios)
                drv_data->set_ios(slot->host, ios);

        switch (ios->power_mode) {
        case MMC_POWER_UP:
                if (!IS_ERR(mmc->supply.vmmc)) {
                        ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
                                        ios->vdd);
                        if (ret) {
                                dev_err(slot->host->dev,
                                        "failed to enable vmmc regulator\n");
                                /*return, if failed turn on vmmc*/
                                return;
                        }
                }
                set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
                regs = mci_readl(slot->host, PWREN);
                regs |= (1 << slot->id);
                mci_writel(slot->host, PWREN, regs);
                break;
        case MMC_POWER_ON:
                if (!slot->host->vqmmc_enabled) {
                        if (!IS_ERR(mmc->supply.vqmmc)) {
                                ret = regulator_enable(mmc->supply.vqmmc);
                                if (ret < 0)
                                        dev_err(slot->host->dev,
                                                "failed to enable vqmmc\n");
                                else
                                        slot->host->vqmmc_enabled = true;

                        } else {
                                /* Keep track so we don't reset again */
                                slot->host->vqmmc_enabled = true;
                        }

                        /* Reset our state machine after powering on */
                        dw_mci_ctrl_reset(slot->host,
                                          SDMMC_CTRL_ALL_RESET_FLAGS);
                }

                /* Adjust clock / bus width after power is up */
                dw_mci_setup_bus(slot, false);

                break;
        case MMC_POWER_OFF:
                /* Turn clock off before power goes down */
                dw_mci_setup_bus(slot, false);

                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);

                if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled)
                        regulator_disable(mmc->supply.vqmmc);
                slot->host->vqmmc_enabled = false;

                regs = mci_readl(slot->host, PWREN);
                regs &= ~(1 << slot->id);
                mci_writel(slot->host, PWREN, regs);
                break;
        default:
                break;
        }

        if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
                slot->host->state = STATE_IDLE;
}

static int dw_mci_card_busy(struct mmc_host *mmc)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        u32 status;

        /*
         * Check the busy bit which is low when DAT[3:0]
         * (the data lines) are 0000
         */
        status = mci_readl(slot->host, STATUS);

        return !!(status & SDMMC_STATUS_BUSY);
}

static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        u32 uhs;
        u32 v18 = SDMMC_UHS_18V << slot->id;
        int ret;

        if (drv_data && drv_data->switch_voltage)
                return drv_data->switch_voltage(mmc, ios);

        /*
         * Program the voltage.  Note that some instances of dw_mmc may use
         * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
         * does no harm but you need to set the regulator directly.  Try both.
         */
        uhs = mci_readl(host, UHS_REG);
        if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
                uhs &= ~v18;
        else
                uhs |= v18;

        if (!IS_ERR(mmc->supply.vqmmc)) {
                ret = mmc_regulator_set_vqmmc(mmc, ios);

                if (ret) {
                        dev_dbg(&mmc->class_dev,
                                         "Regulator set error %d - %s V\n",
                                         ret, uhs & v18 ? "1.8" : "3.3");
                        return ret;
                }
        }
        mci_writel(host, UHS_REG, uhs);

        return 0;
}

static int dw_mci_get_ro(struct mmc_host *mmc)
{
        int read_only;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        int gpio_ro = mmc_gpio_get_ro(mmc);

        /* Use platform get_ro function, else try on board write protect */
        if (gpio_ro >= 0)
                read_only = gpio_ro;
        else
                read_only =
                        mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;

        dev_dbg(&mmc->class_dev, "card is %s\n",
                read_only ? "read-only" : "read-write");

        return read_only;
}

static void dw_mci_hw_reset(struct mmc_host *mmc)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        int reset;

        if (host->use_dma == TRANS_MODE_IDMAC)
                dw_mci_idmac_reset(host);

        if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET |
                                     SDMMC_CTRL_FIFO_RESET))
                return;

        /*
         * According to eMMC spec, card reset procedure:
         * tRstW >= 1us:   RST_n pulse width
         * tRSCA >= 200us: RST_n to Command time
         * tRSTH >= 1us:   RST_n high period
         */
        reset = mci_readl(host, RST_N);
        reset &= ~(SDMMC_RST_HWACTIVE << slot->id);
        mci_writel(host, RST_N, reset);
        usleep_range(1, 2);
        reset |= SDMMC_RST_HWACTIVE << slot->id;
        mci_writel(host, RST_N, reset);
        usleep_range(200, 300);
}

static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;

        /*
         * Low power mode will stop the card clock when idle.  According to the
         * description of the CLKENA register we should disable low power mode
         * for SDIO cards if we need SDIO interrupts to work.
         */
        if (mmc->caps & MMC_CAP_SDIO_IRQ) {
                const u32 clken_low_pwr = SDMMC_CLKEN_LOW_PWR << slot->id;
                u32 clk_en_a_old;
                u32 clk_en_a;

                clk_en_a_old = mci_readl(host, CLKENA);

                if (card->type == MMC_TYPE_SDIO ||
                    card->type == MMC_TYPE_SD_COMBO) {
                        set_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
                        clk_en_a = clk_en_a_old & ~clken_low_pwr;
                } else {
                        clear_bit(DW_MMC_CARD_NO_LOW_PWR, &slot->flags);
                        clk_en_a = clk_en_a_old | clken_low_pwr;
                }

                if (clk_en_a != clk_en_a_old) {
                        mci_writel(host, CLKENA, clk_en_a);
                        mci_send_cmd(slot, SDMMC_CMD_UPD_CLK |
                                     SDMMC_CMD_PRV_DAT_WAIT, 0);
                }
        }
}

static void __dw_mci_enable_sdio_irq(struct dw_mci_slot *slot, int enb)
{
        struct dw_mci *host = slot->host;
        unsigned long irqflags;
        u32 int_mask;

        spin_lock_irqsave(&host->irq_lock, irqflags);

        /* Enable/disable Slot Specific SDIO interrupt */
        int_mask = mci_readl(host, INTMASK);
        if (enb)
                int_mask |= SDMMC_INT_SDIO(slot->sdio_id);
        else
                int_mask &= ~SDMMC_INT_SDIO(slot->sdio_id);
        mci_writel(host, INTMASK, int_mask);

        spin_unlock_irqrestore(&host->irq_lock, irqflags);
}

static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;

        __dw_mci_enable_sdio_irq(slot, enb);

        /* Avoid runtime suspending the device when SDIO IRQ is enabled */
        if (enb)
                pm_runtime_get_noresume(host->dev);
        else
                pm_runtime_put_noidle(host->dev);
}

static void dw_mci_ack_sdio_irq(struct mmc_host *mmc)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);

        __dw_mci_enable_sdio_irq(slot, 1);
}

static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int err = -EINVAL;

        if (drv_data && drv_data->execute_tuning)
                err = drv_data->execute_tuning(slot, opcode);
        return err;
}

static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc,
                                       struct mmc_ios *ios)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct dw_mci *host = slot->host;
        const struct dw_mci_drv_data *drv_data = host->drv_data;

        if (drv_data && drv_data->prepare_hs400_tuning)
                return drv_data->prepare_hs400_tuning(host, ios);

        return 0;
}

static bool dw_mci_reset(struct dw_mci *host)
{
        u32 flags = SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET;
        bool ret = false;
        u32 status = 0;

        /*
         * Resetting generates a block interrupt, hence setting
         * the scatter-gather pointer to NULL.
         */
        if (host->sg) {
                sg_miter_stop(&host->sg_miter);
                host->sg = NULL;
        }

        if (host->use_dma)
                flags |= SDMMC_CTRL_DMA_RESET;

        if (dw_mci_ctrl_reset(host, flags)) {
                /*
                 * In all cases we clear the RAWINTS
                 * register to clear any interrupts.
                 */
                mci_writel(host, RINTSTS, 0xFFFFFFFF);

                if (!host->use_dma) {
                        ret = true;
                        goto ciu_out;
                }

                /* Wait for dma_req to be cleared */
                if (readl_poll_timeout_atomic(host->regs + SDMMC_STATUS,
                                              status,
                                              !(status & SDMMC_STATUS_DMA_REQ),
                                              1, 500 * USEC_PER_MSEC)) {
                        dev_err(host->dev,
                                "%s: Timeout waiting for dma_req to be cleared\n",
                                __func__);
                        goto ciu_out;
                }

                /* when using DMA next we reset the fifo again */
                if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_FIFO_RESET))
                        goto ciu_out;
        } else {
                /* if the controller reset bit did clear, then set clock regs */
                if (!(mci_readl(host, CTRL) & SDMMC_CTRL_RESET)) {
                        dev_err(host->dev,
                                "%s: fifo/dma reset bits didn't clear but ciu was reset, doing clock update\n",
                                __func__);
                        goto ciu_out;
                }
        }

        if (host->use_dma == TRANS_MODE_IDMAC)
                /* It is also required that we reinit idmac */
                dw_mci_idmac_init(host);

        ret = true;

ciu_out:
        /* After a CTRL reset we need to have CIU set clock registers  */
        mci_send_cmd(host->slot, SDMMC_CMD_UPD_CLK, 0);

        return ret;
}

static const struct mmc_host_ops dw_mci_ops = {
        .request                = dw_mci_request,
        .pre_req                = dw_mci_pre_req,
        .post_req               = dw_mci_post_req,
        .set_ios                = dw_mci_set_ios,
        .get_ro                 = dw_mci_get_ro,
        .get_cd                 = dw_mci_get_cd,
        .hw_reset               = dw_mci_hw_reset,
        .enable_sdio_irq        = dw_mci_enable_sdio_irq,
        .ack_sdio_irq           = dw_mci_ack_sdio_irq,
        .execute_tuning         = dw_mci_execute_tuning,
        .card_busy              = dw_mci_card_busy,
        .start_signal_voltage_switch = dw_mci_switch_voltage,
        .init_card              = dw_mci_init_card,
        .prepare_hs400_tuning   = dw_mci_prepare_hs400_tuning,
};

static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
        __releases(&host->lock)
        __acquires(&host->lock)
{
        struct dw_mci_slot *slot;
        struct mmc_host *prev_mmc = host->slot->mmc;

        WARN_ON(host->cmd || host->data);

        host->slot->mrq = NULL;
        host->mrq = NULL;
        if (!list_empty(&host->queue)) {
                slot = list_entry(host->queue.next,
                                  struct dw_mci_slot, queue_node);
                list_del(&slot->queue_node);
                dev_vdbg(host->dev, "list not empty: %s is next\n",
                         mmc_hostname(slot->mmc));
                host->state = STATE_SENDING_CMD;
                dw_mci_start_request(host, slot);
        } else {
                dev_vdbg(host->dev, "list empty\n");

                if (host->state == STATE_SENDING_CMD11)
                        host->state = STATE_WAITING_CMD11_DONE;
                else
                        host->state = STATE_IDLE;
        }

        spin_unlock(&host->lock);
        mmc_request_done(prev_mmc, mrq);
        spin_lock(&host->lock);
}

static int dw_mci_command_complete(struct dw_mci *host, struct mmc_command *cmd)
{
        u32 status = host->cmd_status;

        host->cmd_status = 0;

        /* Read the response from the card (up to 16 bytes) */
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        cmd->resp[3] = mci_readl(host, RESP0);
                        cmd->resp[2] = mci_readl(host, RESP1);
                        cmd->resp[1] = mci_readl(host, RESP2);
                        cmd->resp[0] = mci_readl(host, RESP3);
                } else {
                        cmd->resp[0] = mci_readl(host, RESP0);
                        cmd->resp[1] = 0;
                        cmd->resp[2] = 0;
                        cmd->resp[3] = 0;
                }
        }

        if (status & SDMMC_INT_RTO)
                cmd->error = -ETIMEDOUT;
        else if ((cmd->flags & MMC_RSP_CRC) && (status & SDMMC_INT_RCRC))
                cmd->error = -EILSEQ;
        else if (status & SDMMC_INT_RESP_ERR)
                cmd->error = -EIO;
        else
                cmd->error = 0;

        return cmd->error;
}

static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
{
        u32 status = host->data_status;

        if (status & DW_MCI_DATA_ERROR_FLAGS) {
                if (status & SDMMC_INT_DRTO) {
                        data->error = -ETIMEDOUT;
                } else if (status & SDMMC_INT_DCRC) {
                        data->error = -EILSEQ;
                } else if (status & SDMMC_INT_EBE) {
                        if (host->dir_status ==
                                DW_MCI_SEND_STATUS) {
                                /*
                                 * No data CRC status was returned.
                                 * The number of bytes transferred
                                 * will be exaggerated in PIO mode.
                                 */
                                data->bytes_xfered = 0;
                                data->error = -ETIMEDOUT;
                        } else if (host->dir_status ==
                                        DW_MCI_RECV_STATUS) {
                                data->error = -EILSEQ;
                        }
                } else {
                        /* SDMMC_INT_SBE is included */
                        data->error = -EILSEQ;
                }

                dev_dbg(host->dev, "data error, status 0x%08x\n", status);

                /*
                 * After an error, there may be data lingering
                 * in the FIFO
                 */
                dw_mci_reset(host);
        } else {
                data->bytes_xfered = data->blocks * data->blksz;
                data->error = 0;
        }

        return data->error;
}

static void dw_mci_set_drto(struct dw_mci *host)
{
        unsigned int drto_clks;
        unsigned int drto_div;
        unsigned int drto_ms;
        unsigned long irqflags;

        drto_clks = mci_readl(host, TMOUT) >> 8;
        drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
        if (drto_div == 0)
                drto_div = 1;

        drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div,
                                   host->bus_hz);

        /* add a bit spare time */
        drto_ms += 10;

        spin_lock_irqsave(&host->irq_lock, irqflags);
        if (!test_bit(EVENT_DATA_COMPLETE, &host->pending_events))
                mod_timer(&host->dto_timer,
                          jiffies + msecs_to_jiffies(drto_ms));
        spin_unlock_irqrestore(&host->irq_lock, irqflags);
}

static bool dw_mci_clear_pending_cmd_complete(struct dw_mci *host)
{
        if (!test_bit(EVENT_CMD_COMPLETE, &host->pending_events))
                return false;

        /*
         * Really be certain that the timer has stopped.  This is a bit of
         * paranoia and could only really happen if we had really bad
         * interrupt latency and the interrupt routine and timeout were
         * running concurrently so that the del_timer() in the interrupt
         * handler couldn't run.
         */
        WARN_ON(del_timer_sync(&host->cto_timer));
        clear_bit(EVENT_CMD_COMPLETE, &host->pending_events);

        return true;
}

static bool dw_mci_clear_pending_data_complete(struct dw_mci *host)
{
        if (!test_bit(EVENT_DATA_COMPLETE, &host->pending_events))
                return false;

        /* Extra paranoia just like dw_mci_clear_pending_cmd_complete() */
        WARN_ON(del_timer_sync(&host->dto_timer));
        clear_bit(EVENT_DATA_COMPLETE, &host->pending_events);

        return true;
}

static void dw_mci_tasklet_func(unsigned long priv)
{
        struct dw_mci *host = (struct dw_mci *)priv;
        struct mmc_data *data;
        struct mmc_command *cmd;
        struct mmc_request *mrq;
        enum dw_mci_state state;
        enum dw_mci_state prev_state;
        unsigned int err;

        spin_lock(&host->lock);

        state = host->state;
        data = host->data;
        mrq = host->mrq;

        do {
                prev_state = state;

                switch (state) {
                case STATE_IDLE:

                case STATE_WAITING_CMD11_DONE:
                        break;

                case STATE_SENDING_CMD11:
                case STATE_SENDING_CMD:
                        if (!dw_mci_clear_pending_cmd_complete(host))
                                break;

                        cmd = host->cmd;
                        host->cmd = NULL;
                        set_bit(EVENT_CMD_COMPLETE, &host->completed_events);
                        err = dw_mci_command_complete(host, cmd);
                        if (cmd == mrq->sbc && !err) {
                                __dw_mci_start_request(host, host->slot,
                                                       mrq->cmd);
                                goto unlock;
                        }

                        if (cmd->data && err) {
                                /*
                                 * During UHS tuning sequence, sending the stop
                                 * command after the response CRC error would
                                 * throw the system into a confused state
                                 * causing all future tuning phases to report
                                 * failure.
                                 *
                                 * In such case controller will move into a data
                                 * transfer state after a response error or
                                 * response CRC error. Let's let that finish
                                 * before trying to send a stop, so we'll go to
                                 * STATE_SENDING_DATA.
                                 *
                                 * Although letting the data transfer take place
                                 * will waste a bit of time (we already know
                                 * the command was bad), it can't cause any
                                 * errors since it's possible it would have
                                 * taken place anyway if this tasklet got
                                 * delayed. Allowing the transfer to take place
                                 * avoids races and keeps things simple.
                                 */
                                if ((err != -ETIMEDOUT) &&
                                    (cmd->opcode == MMC_SEND_TUNING_BLOCK)) {
                                        state = STATE_SENDING_DATA;
                                        continue;
                                }

                                dw_mci_stop_dma(host);
                                send_stop_abort(host, data);
                                state = STATE_SENDING_STOP;
                                break;
                        }

                        if (!cmd->data || err) {
                                dw_mci_request_end(host, mrq);
                                goto unlock;
                        }

                        prev_state = state = STATE_SENDING_DATA;
                        /* fall through */

                case STATE_SENDING_DATA:
                        /*
                         * We could get a data error and never a transfer
                         * complete so we'd better check for it here.
                         *
                         * Note that we don't really care if we also got a
                         * transfer complete; stopping the DMA and sending an
                         * abort won't hurt.
                         */
                        if (test_and_clear_bit(EVENT_DATA_ERROR,
                                               &host->pending_events)) {
                                dw_mci_stop_dma(host);
                                if (!(host->data_status & (SDMMC_INT_DRTO |
                                                           SDMMC_INT_EBE)))
                                        send_stop_abort(host, data);
                                state = STATE_DATA_ERROR;
                                break;
                        }

                        if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
                                                &host->pending_events)) {
                                /*
                                 * If all data-related interrupts don't come
                                 * within the given time in reading data state.
                                 */
                                if (host->dir_status == DW_MCI_RECV_STATUS)
                                        dw_mci_set_drto(host);
                                break;
                        }

                        set_bit(EVENT_XFER_COMPLETE, &host->completed_events);

                        /*
                         * Handle an EVENT_DATA_ERROR that might have shown up
                         * before the transfer completed.  This might not have
                         * been caught by the check above because the interrupt
                         * could have gone off between the previous check and
                         * the check for transfer complete.
                         *
                         * Technically this ought not be needed assuming we
                         * get a DATA_COMPLETE eventually (we'll notice the
                         * error and end the request), but it shouldn't hurt.
                         *
                         * This has the advantage of sending the stop command.
                         */
                        if (test_and_clear_bit(EVENT_DATA_ERROR,
                                               &host->pending_events)) {
                                dw_mci_stop_dma(host);
                                if (!(host->data_status & (SDMMC_INT_DRTO |
                                                           SDMMC_INT_EBE)))
                                        send_stop_abort(host, data);
                                state = STATE_DATA_ERROR;
                                break;
                        }
                        prev_state = state = STATE_DATA_BUSY;

                        /* fall through */

                case STATE_DATA_BUSY:
                        if (!dw_mci_clear_pending_data_complete(host)) {
                                /*
                                 * If data error interrupt comes but data over
                                 * interrupt doesn't come within the given time.
                                 * in reading data state.
                                 */
                                if (host->dir_status == DW_MCI_RECV_STATUS)
                                        dw_mci_set_drto(host);
                                break;
                        }

                        host->data = NULL;
                        set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
                        err = dw_mci_data_complete(host, data);

                        if (!err) {
                                if (!data->stop || mrq->sbc) {
                                        if (mrq->sbc && data->stop)
                                                data->stop->error = 0;
                                        dw_mci_request_end(host, mrq);
                                        goto unlock;
                                }

                                /* stop command for open-ended transfer*/
                                if (data->stop)
                                        send_stop_abort(host, data);
                        } else {
                                /*
                                 * If we don't have a command complete now we'll
                                 * never get one since we just reset everything;
                                 * better end the request.
                                 *
                                 * If we do have a command complete we'll fall
                                 * through to the SENDING_STOP command and
                                 * everything will be peachy keen.
                                 */
                                if (!test_bit(EVENT_CMD_COMPLETE,
                                              &host->pending_events)) {
                                        host->cmd = NULL;
                                        dw_mci_request_end(host, mrq);
                                        goto unlock;
                                }
                        }

                        /*
                         * If err has non-zero,
                         * stop-abort command has been already issued.
                         */
                        prev_state = state = STATE_SENDING_STOP;

                        /* fall through */

                case STATE_SENDING_STOP:
                        if (!dw_mci_clear_pending_cmd_complete(host))
                                break;

                        /* CMD error in data command */
                        if (mrq->cmd->error && mrq->data)
                                dw_mci_reset(host);

                        host->cmd = NULL;
                        host->data = NULL;

                        if (!mrq->sbc && mrq->stop)
                                dw_mci_command_complete(host, mrq->stop);
                        else
                                host->cmd_status = 0;

                        dw_mci_request_end(host, mrq);
                        goto unlock;

                case STATE_DATA_ERROR:
                        if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
                                                &host->pending_events))
                                break;

                        state = STATE_DATA_BUSY;
                        break;
                }
        } while (state != prev_state);

        host->state = state;
unlock:
        spin_unlock(&host->lock);

}

/* push final bytes to part_buf, only use during push */
static void dw_mci_set_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        memcpy((void *)&host->part_buf, buf, cnt);
        host->part_buf_count = cnt;
}

/* append bytes to part_buf, only use during push */
static int dw_mci_push_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        cnt = min(cnt, (1 << host->data_shift) - host->part_buf_count);
        memcpy((void *)&host->part_buf + host->part_buf_count, buf, cnt);
        host->part_buf_count += cnt;
        return cnt;
}

/* pull first bytes from part_buf, only use during pull */
static int dw_mci_pull_part_bytes(struct dw_mci *host, void *buf, int cnt)
{
        cnt = min_t(int, cnt, host->part_buf_count);
        if (cnt) {
                memcpy(buf, (void *)&host->part_buf + host->part_buf_start,
                       cnt);
                host->part_buf_count -= cnt;
                host->part_buf_start += cnt;
        }
        return cnt;
}

/* pull final bytes from the part_buf, assuming it's just been filled */
static void dw_mci_pull_final_bytes(struct dw_mci *host, void *buf, int cnt)
{
        memcpy(buf, &host->part_buf, cnt);
        host->part_buf_start = cnt;
        host->part_buf_count = (1 << host->data_shift) - cnt;
}

static void dw_mci_push_data16(struct dw_mci *host, void *buf, int cnt)
{
        struct mmc_data *data = host->data;
        int init_cnt = cnt;

        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);

                buf += len;
                cnt -= len;
                if (host->part_buf_count == 2) {
                        mci_fifo_writew(host->fifo_reg, host->part_buf16);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x1)) {
                while (cnt >= 2) {
                        u16 aligned_buf[64];
                        int len = min(cnt & -2, (int)sizeof(aligned_buf));
                        int items = len >> 1;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_fifo_writew(host->fifo_reg, aligned_buf[i]);
                }
        } else
#endif
        {
                u16 *pdata = buf;

                for (; cnt >= 2; cnt -= 2)
                        mci_fifo_writew(host->fifo_reg, *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                 /* Push data if we have reached the expected data length */
                if ((data->bytes_xfered + init_cnt) ==
                    (data->blksz * data->blocks))
                        mci_fifo_writew(host->fifo_reg, host->part_buf16);
        }
}

static void dw_mci_pull_data16(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x1)) {
                while (cnt >= 2) {
                        /* pull data from fifo into aligned buffer */
                        u16 aligned_buf[64];
                        int len = min(cnt & -2, (int)sizeof(aligned_buf));
                        int items = len >> 1;
                        int i;

                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_fifo_readw(host->fifo_reg);
                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u16 *pdata = buf;

                for (; cnt >= 2; cnt -= 2)
                        *pdata++ = mci_fifo_readw(host->fifo_reg);
                buf = pdata;
        }
        if (cnt) {
                host->part_buf16 = mci_fifo_readw(host->fifo_reg);
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_push_data32(struct dw_mci *host, void *buf, int cnt)
{
        struct mmc_data *data = host->data;
        int init_cnt = cnt;

        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);

                buf += len;
                cnt -= len;
                if (host->part_buf_count == 4) {
                        mci_fifo_writel(host->fifo_reg, host->part_buf32);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x3)) {
                while (cnt >= 4) {
                        u32 aligned_buf[32];
                        int len = min(cnt & -4, (int)sizeof(aligned_buf));
                        int items = len >> 2;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_fifo_writel(host->fifo_reg, aligned_buf[i]);
                }
        } else
#endif
        {
                u32 *pdata = buf;

                for (; cnt >= 4; cnt -= 4)
                        mci_fifo_writel(host->fifo_reg, *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                 /* Push data if we have reached the expected data length */
                if ((data->bytes_xfered + init_cnt) ==
                    (data->blksz * data->blocks))
                        mci_fifo_writel(host->fifo_reg, host->part_buf32);
        }
}

static void dw_mci_pull_data32(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x3)) {
                while (cnt >= 4) {
                        /* pull data from fifo into aligned buffer */
                        u32 aligned_buf[32];
                        int len = min(cnt & -4, (int)sizeof(aligned_buf));
                        int items = len >> 2;
                        int i;

                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_fifo_readl(host->fifo_reg);
                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u32 *pdata = buf;

                for (; cnt >= 4; cnt -= 4)
                        *pdata++ = mci_fifo_readl(host->fifo_reg);
                buf = pdata;
        }
        if (cnt) {
                host->part_buf32 = mci_fifo_readl(host->fifo_reg);
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_push_data64(struct dw_mci *host, void *buf, int cnt)
{
        struct mmc_data *data = host->data;
        int init_cnt = cnt;

        /* try and push anything in the part_buf */
        if (unlikely(host->part_buf_count)) {
                int len = dw_mci_push_part_bytes(host, buf, cnt);

                buf += len;
                cnt -= len;

                if (host->part_buf_count == 8) {
                        mci_fifo_writeq(host->fifo_reg, host->part_buf);
                        host->part_buf_count = 0;
                }
        }
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x7)) {
                while (cnt >= 8) {
                        u64 aligned_buf[16];
                        int len = min(cnt & -8, (int)sizeof(aligned_buf));
                        int items = len >> 3;
                        int i;
                        /* memcpy from input buffer into aligned buffer */
                        memcpy(aligned_buf, buf, len);
                        buf += len;
                        cnt -= len;
                        /* push data from aligned buffer into fifo */
                        for (i = 0; i < items; ++i)
                                mci_fifo_writeq(host->fifo_reg, aligned_buf[i]);
                }
        } else
#endif
        {
                u64 *pdata = buf;

                for (; cnt >= 8; cnt -= 8)
                        mci_fifo_writeq(host->fifo_reg, *pdata++);
                buf = pdata;
        }
        /* put anything remaining in the part_buf */
        if (cnt) {
                dw_mci_set_part_bytes(host, buf, cnt);
                /* Push data if we have reached the expected data length */
                if ((data->bytes_xfered + init_cnt) ==
                    (data->blksz * data->blocks))
                        mci_fifo_writeq(host->fifo_reg, host->part_buf);
        }
}

static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt)
{
#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
        if (unlikely((unsigned long)buf & 0x7)) {
                while (cnt >= 8) {
                        /* pull data from fifo into aligned buffer */
                        u64 aligned_buf[16];
                        int len = min(cnt & -8, (int)sizeof(aligned_buf));
                        int items = len >> 3;
                        int i;

                        for (i = 0; i < items; ++i)
                                aligned_buf[i] = mci_fifo_readq(host->fifo_reg);

                        /* memcpy from aligned buffer into output buffer */
                        memcpy(buf, aligned_buf, len);
                        buf += len;
                        cnt -= len;
                }
        } else
#endif
        {
                u64 *pdata = buf;

                for (; cnt >= 8; cnt -= 8)
                        *pdata++ = mci_fifo_readq(host->fifo_reg);
                buf = pdata;
        }
        if (cnt) {
                host->part_buf = mci_fifo_readq(host->fifo_reg);
                dw_mci_pull_final_bytes(host, buf, cnt);
        }
}

static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt)
{
        int len;

        /* get remaining partial bytes */
        len = dw_mci_pull_part_bytes(host, buf, cnt);
        if (unlikely(len == cnt))
                return;
        buf += len;
        cnt -= len;

        /* get the rest of the data */
        host->pull_data(host, buf, cnt);
}

static void dw_mci_read_data_pio(struct dw_mci *host, bool dto)
{
        struct sg_mapping_iter *sg_miter = &host->sg_miter;
        void *buf;
        unsigned int offset;
        struct mmc_data *data = host->data;
        int shift = host->data_shift;
        u32 status;
        unsigned int len;
        unsigned int remain, fcnt;

        do {
                if (!sg_miter_next(sg_miter))
                        goto done;

                host->sg = sg_miter->piter.sg;
                buf = sg_miter->addr;
                remain = sg_miter->length;
                offset = 0;

                do {
                        fcnt = (SDMMC_GET_FCNT(mci_readl(host, STATUS))
                                        << shift) + host->part_buf_count;
                        len = min(remain, fcnt);
                        if (!len)
                                break;
                        dw_mci_pull_data(host, (void *)(buf + offset), len);
                        data->bytes_xfered += len;
                        offset += len;
                        remain -= len;
                } while (remain);

                sg_miter->consumed = offset;
                status = mci_readl(host, MINTSTS);
                mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
        /* if the RXDR is ready read again */
        } while ((status & SDMMC_INT_RXDR) ||
                 (dto && SDMMC_GET_FCNT(mci_readl(host, STATUS))));

        if (!remain) {
                if (!sg_miter_next(sg_miter))
                        goto done;
                sg_miter->consumed = 0;
        }
        sg_miter_stop(sg_miter);
        return;

done:
        sg_miter_stop(sg_miter);
        host->sg = NULL;
        smp_wmb(); /* drain writebuffer */
        set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
}

static void dw_mci_write_data_pio(struct dw_mci *host)
{
        struct sg_mapping_iter *sg_miter = &host->sg_miter;
        void *buf;
        unsigned int offset;
        struct mmc_data *data = host->data;
        int shift = host->data_shift;
        u32 status;
        unsigned int len;
        unsigned int fifo_depth = host->fifo_depth;
        unsigned int remain, fcnt;

        do {
                if (!sg_miter_next(sg_miter))
                        goto done;

                host->sg = sg_miter->piter.sg;
                buf = sg_miter->addr;
                remain = sg_miter->length;
                offset = 0;

                do {
                        fcnt = ((fifo_depth -
                                 SDMMC_GET_FCNT(mci_readl(host, STATUS)))
                                        << shift) - host->part_buf_count;
                        len = min(remain, fcnt);
                        if (!len)
                                break;
                        host->push_data(host, (void *)(buf + offset), len);
                        data->bytes_xfered += len;
                        offset += len;
                        remain -= len;
                } while (remain);

                sg_miter->consumed = offset;
                status = mci_readl(host, MINTSTS);
                mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
        } while (status & SDMMC_INT_TXDR); /* if TXDR write again */

        if (!remain) {
                if (!sg_miter_next(sg_miter))
                        goto done;
                sg_miter->consumed = 0;
        }
        sg_miter_stop(sg_miter);
        return;

done:
        sg_miter_stop(sg_miter);
        host->sg = NULL;
        smp_wmb(); /* drain writebuffer */
        set_bit(EVENT_XFER_COMPLETE, &host->pending_events);
}

static void dw_mci_cmd_interrupt(struct dw_mci *host, u32 status)
{
        del_timer(&host->cto_timer);

        if (!host->cmd_status)
                host->cmd_status = status;

        smp_wmb(); /* drain writebuffer */

        set_bit(EVENT_CMD_COMPLETE, &host->pending_events);
        tasklet_schedule(&host->tasklet);
}

static void dw_mci_handle_cd(struct dw_mci *host)
{
        struct dw_mci_slot *slot = host->slot;

        if (slot->mmc->ops->card_event)
                slot->mmc->ops->card_event(slot->mmc);
        mmc_detect_change(slot->mmc,
                msecs_to_jiffies(host->pdata->detect_delay_ms));
}

static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
{
        struct dw_mci *host = dev_id;
        u32 pending;
        struct dw_mci_slot *slot = host->slot;
        unsigned long irqflags;

        pending = mci_readl(host, MINTSTS); /* read-only mask reg */

        if (pending) {
                /* Check volt switch first, since it can look like an error */
                if ((host->state == STATE_SENDING_CMD11) &&
                    (pending & SDMMC_INT_VOLT_SWITCH)) {
                        mci_writel(host, RINTSTS, SDMMC_INT_VOLT_SWITCH);
                        pending &= ~SDMMC_INT_VOLT_SWITCH;

                        /*
                         * Hold the lock; we know cmd11_timer can't be kicked
                         * off after the lock is released, so safe to delete.
                         */
                        spin_lock_irqsave(&host->irq_lock, irqflags);
                        dw_mci_cmd_interrupt(host, pending);
                        spin_unlock_irqrestore(&host->irq_lock, irqflags);

                        del_timer(&host->cmd11_timer);
                }

                if (pending & DW_MCI_CMD_ERROR_FLAGS) {
                        spin_lock_irqsave(&host->irq_lock, irqflags);

                        del_timer(&host->cto_timer);
                        mci_writel(host, RINTSTS, DW_MCI_CMD_ERROR_FLAGS);
                        host->cmd_status = pending;
                        smp_wmb(); /* drain writebuffer */
                        set_bit(EVENT_CMD_COMPLETE, &host->pending_events);

                        spin_unlock_irqrestore(&host->irq_lock, irqflags);
                }

                if (pending & DW_MCI_DATA_ERROR_FLAGS) {
                        /* if there is an error report DATA_ERROR */
                        mci_writel(host, RINTSTS, DW_MCI_DATA_ERROR_FLAGS);
                        host->data_status = pending;
                        smp_wmb(); /* drain writebuffer */
                        set_bit(EVENT_DATA_ERROR, &host->pending_events);
                        tasklet_schedule(&host->tasklet);
                }

                if (pending & SDMMC_INT_DATA_OVER) {
                        spin_lock_irqsave(&host->irq_lock, irqflags);

                        del_timer(&host->dto_timer);

                        mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
                        if (!host->data_status)
                                host->data_status = pending;
                        smp_wmb(); /* drain writebuffer */
                        if (host->dir_status == DW_MCI_RECV_STATUS) {
                                if (host->sg != NULL)
                                        dw_mci_read_data_pio(host, true);
                        }
                        set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
                        tasklet_schedule(&host->tasklet);

                        spin_unlock_irqrestore(&host->irq_lock, irqflags);
                }

                if (pending & SDMMC_INT_RXDR) {
                        mci_writel(host, RINTSTS, SDMMC_INT_RXDR);
                        if (host->dir_status == DW_MCI_RECV_STATUS && host->sg)
                                dw_mci_read_data_pio(host, false);
                }

                if (pending & SDMMC_INT_TXDR) {
                        mci_writel(host, RINTSTS, SDMMC_INT_TXDR);
                        if (host->dir_status == DW_MCI_SEND_STATUS && host->sg)
                                dw_mci_write_data_pio(host);
                }

                if (pending & SDMMC_INT_CMD_DONE) {
                        spin_lock_irqsave(&host->irq_lock, irqflags);

                        mci_writel(host, RINTSTS, SDMMC_INT_CMD_DONE);
                        dw_mci_cmd_interrupt(host, pending);

                        spin_unlock_irqrestore(&host->irq_lock, irqflags);
                }

                if (pending & SDMMC_INT_CD) {
                        mci_writel(host, RINTSTS, SDMMC_INT_CD);
                        dw_mci_handle_cd(host);
                }

                if (pending & SDMMC_INT_SDIO(slot->sdio_id)) {
                        mci_writel(host, RINTSTS,
                                   SDMMC_INT_SDIO(slot->sdio_id));
                        __dw_mci_enable_sdio_irq(slot, 0);
                        sdio_signal_irq(slot->mmc);
                }

        }

        if (host->use_dma != TRANS_MODE_IDMAC)
                return IRQ_HANDLED;

        /* Handle IDMA interrupts */
        if (host->dma_64bit_address == 1) {
                pending = mci_readl(host, IDSTS64);
                if (pending & (SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI)) {
                        mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_TI |
                                                        SDMMC_IDMAC_INT_RI);
                        mci_writel(host, IDSTS64, SDMMC_IDMAC_INT_NI);
                        if (!test_bit(EVENT_DATA_ERROR, &host->pending_events))
                                host->dma_ops->complete((void *)host);
                }
        } else {
                pending = mci_readl(host, IDSTS);
                if (pending & (SDMMC_IDMAC_INT_TI | SDMMC_IDMAC_INT_RI)) {
                        mci_writel(host, IDSTS, SDMMC_IDMAC_INT_TI |
                                                        SDMMC_IDMAC_INT_RI);
                        mci_writel(host, IDSTS, SDMMC_IDMAC_INT_NI);
                        if (!test_bit(EVENT_DATA_ERROR, &host->pending_events))
                                host->dma_ops->complete((void *)host);
                }
        }

        return IRQ_HANDLED;
}

static int dw_mci_init_slot_caps(struct dw_mci_slot *slot)
{
        struct dw_mci *host = slot->host;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        struct mmc_host *mmc = slot->mmc;
        int ctrl_id;

        if (host->pdata->caps)
                mmc->caps = host->pdata->caps;

        /*
         * Support MMC_CAP_ERASE by default.
         * It needs to use trim/discard/erase commands.
         */
        mmc->caps |= MMC_CAP_ERASE;

        if (host->pdata->pm_caps)
                mmc->pm_caps = host->pdata->pm_caps;

        if (host->dev->of_node) {
                ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
                if (ctrl_id < 0)
                        ctrl_id = 0;
        } else {
                ctrl_id = to_platform_device(host->dev)->id;
        }

        if (drv_data && drv_data->caps) {
                if (ctrl_id >= drv_data->num_caps) {
                        dev_err(host->dev, "invalid controller id %d\n",
                                ctrl_id);
                        return -EINVAL;
                }
                mmc->caps |= drv_data->caps[ctrl_id];
        }

        if (host->pdata->caps2)
                mmc->caps2 = host->pdata->caps2;

        mmc->f_min = DW_MCI_FREQ_MIN;
        if (!mmc->f_max)
                mmc->f_max = DW_MCI_FREQ_MAX;

        /* Process SDIO IRQs through the sdio_irq_work. */
        if (mmc->caps & MMC_CAP_SDIO_IRQ)
                mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;

        return 0;
}

static int dw_mci_init_slot(struct dw_mci *host)
{
        struct mmc_host *mmc;
        struct dw_mci_slot *slot;
        int ret;

        mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
        if (!mmc)
                return -ENOMEM;

        slot = mmc_priv(mmc);
        slot->id = 0;
        slot->sdio_id = host->sdio_id0 + slot->id;
        slot->mmc = mmc;
        slot->host = host;
        host->slot = slot;

        mmc->ops = &dw_mci_ops;

        /*if there are external regulators, get them*/
        ret = mmc_regulator_get_supply(mmc);
        if (ret)
                goto err_host_allocated;

        if (!mmc->ocr_avail)
                mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;

        ret = mmc_of_parse(mmc);
        if (ret)
                goto err_host_allocated;

        ret = dw_mci_init_slot_caps(slot);
        if (ret)
                goto err_host_allocated;

        /* Useful defaults if platform data is unset. */
        if (host->use_dma == TRANS_MODE_IDMAC) {
                mmc->max_segs = host->ring_size;
                mmc->max_blk_size = 65535;
                mmc->max_seg_size = 0x1000;
                mmc->max_req_size = mmc->max_seg_size * host->ring_size;
                mmc->max_blk_count = mmc->max_req_size / 512;
        } else if (host->use_dma == TRANS_MODE_EDMAC) {
                mmc->max_segs = 64;
                mmc->max_blk_size = 65535;
                mmc->max_blk_count = 65535;
                mmc->max_req_size =
                                mmc->max_blk_size * mmc->max_blk_count;
                mmc->max_seg_size = mmc->max_req_size;
        } else {
                /* TRANS_MODE_PIO */
                mmc->max_segs = 64;
                mmc->max_blk_size = 65535; /* BLKSIZ is 16 bits */
                mmc->max_blk_count = 512;
                mmc->max_req_size = mmc->max_blk_size *
                                    mmc->max_blk_count;
                mmc->max_seg_size = mmc->max_req_size;
        }

        dw_mci_get_cd(mmc);

        ret = mmc_add_host(mmc);
        if (ret)
                goto err_host_allocated;

#if defined(CONFIG_DEBUG_FS)
        dw_mci_init_debugfs(slot);
#endif

        return 0;

err_host_allocated:
        mmc_free_host(mmc);
        return ret;
}

static void dw_mci_cleanup_slot(struct dw_mci_slot *slot)
{
        /* Debugfs stuff is cleaned up by mmc core */
        mmc_remove_host(slot->mmc);
        slot->host->slot = NULL;
        mmc_free_host(slot->mmc);
}

static void dw_mci_init_dma(struct dw_mci *host)
{
        int addr_config;
        struct device *dev = host->dev;

        /*
        * Check tansfer mode from HCON[17:16]
        * Clear the ambiguous description of dw_mmc databook:
        * 2b'00: No DMA Interface -> Actually means using Internal DMA block
        * 2b'01: DesignWare DMA Interface -> Synopsys DW-DMA block
        * 2b'10: Generic DMA Interface -> non-Synopsys generic DMA block
        * 2b'11: Non DW DMA Interface -> pio only
        * Compared to DesignWare DMA Interface, Generic DMA Interface has a
        * simpler request/acknowledge handshake mechanism and both of them
        * are regarded as external dma master for dw_mmc.
        */
        host->use_dma = SDMMC_GET_TRANS_MODE(mci_readl(host, HCON));
        if (host->use_dma == DMA_INTERFACE_IDMA) {
                host->use_dma = TRANS_MODE_IDMAC;
        } else if (host->use_dma == DMA_INTERFACE_DWDMA ||
                   host->use_dma == DMA_INTERFACE_GDMA) {
                host->use_dma = TRANS_MODE_EDMAC;
        } else {
                goto no_dma;
        }

        /* Determine which DMA interface to use */
        if (host->use_dma == TRANS_MODE_IDMAC) {
                /*
                * Check ADDR_CONFIG bit in HCON to find
                * IDMAC address bus width
                */
                addr_config = SDMMC_GET_ADDR_CONFIG(mci_readl(host, HCON));

                if (addr_config == 1) {
                        /* host supports IDMAC in 64-bit address mode */
                        host->dma_64bit_address = 1;
                        dev_info(host->dev,
                                 "IDMAC supports 64-bit address mode.\n");
                        if (!dma_set_mask(host->dev, DMA_BIT_MASK(64)))
                                dma_set_coherent_mask(host->dev,
                                                      DMA_BIT_MASK(64));
                } else {
                        /* host supports IDMAC in 32-bit address mode */
                        host->dma_64bit_address = 0;
                        dev_info(host->dev,
                                 "IDMAC supports 32-bit address mode.\n");
                }

                /* Alloc memory for sg translation */
                host->sg_cpu = dmam_alloc_coherent(host->dev,
                                                   DESC_RING_BUF_SZ,
                                                   &host->sg_dma, GFP_KERNEL);
                if (!host->sg_cpu) {
                        dev_err(host->dev,
                                "%s: could not alloc DMA memory\n",
                                __func__);
                        goto no_dma;
                }

                host->dma_ops = &dw_mci_idmac_ops;
                dev_info(host->dev, "Using internal DMA controller.\n");
        } else {
                /* TRANS_MODE_EDMAC: check dma bindings again */
                if ((device_property_read_string_array(dev, "dma-names",
                                                       NULL, 0) < 0) ||
                    !device_property_present(dev, "dmas")) {
                        goto no_dma;
                }
                host->dma_ops = &dw_mci_edmac_ops;
                dev_info(host->dev, "Using external DMA controller.\n");
        }

        if (host->dma_ops->init && host->dma_ops->start &&
            host->dma_ops->stop && host->dma_ops->cleanup) {
                if (host->dma_ops->init(host)) {
                        dev_err(host->dev, "%s: Unable to initialize DMA Controller.\n",
                                __func__);
                        goto no_dma;
                }
        } else {
                dev_err(host->dev, "DMA initialization not found.\n");
                goto no_dma;
        }

        return;

no_dma:
        dev_info(host->dev, "Using PIO mode.\n");
        host->use_dma = TRANS_MODE_PIO;
}

static void dw_mci_cmd11_timer(struct timer_list *t)
{
        struct dw_mci *host = from_timer(host, t, cmd11_timer);

        if (host->state != STATE_SENDING_CMD11) {