[platform/kernel/linux-rpi.git] / drivers / mmc / host / dw_mmc.c

/*
 * 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/ioport.h>
#include <linux/module.h>
#include <linux/platform_device.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/mmc/dw_mmc.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 400000          /* 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)

struct idmac_desc_64addr {
        u32             des0;   /* Control Descriptor */

        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

static bool dw_mci_reset(struct dw_mci *host);
static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset);
static int dw_mci_card_busy(struct mmc_host *mmc);
static int dw_mci_get_cd(struct mmc_host *mmc);

#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;
}

static int dw_mci_req_open(struct inode *inode, struct file *file)
{
        return single_open(file, dw_mci_req_show, inode->i_private);
}

static const struct file_operations dw_mci_req_fops = {
        .owner          = THIS_MODULE,
        .open           = dw_mci_req_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int dw_mci_regs_show(struct seq_file *s, void *v)
{
        seq_printf(s, "STATUS:\t0x%08x\n", SDMMC_STATUS);
        seq_printf(s, "RINTSTS:\t0x%08x\n", SDMMC_RINTSTS);
        seq_printf(s, "CMD:\t0x%08x\n", SDMMC_CMD);
        seq_printf(s, "CTRL:\t0x%08x\n", SDMMC_CTRL);
        seq_printf(s, "INTMASK:\t0x%08x\n", SDMMC_INTMASK);
        seq_printf(s, "CLKENA:\t0x%08x\n", SDMMC_CLKENA);

        return 0;
}

static int dw_mci_regs_open(struct inode *inode, struct file *file)
{
        return single_open(file, dw_mci_regs_show, inode->i_private);
}

static const struct file_operations dw_mci_regs_fops = {
        .owner          = THIS_MODULE,
        .open           = dw_mci_regs_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

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 void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg);

static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
{
        struct mmc_data *data;
        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;

        data = cmd->data;
        if (data) {
                cmdr |= SDMMC_CMD_DAT_EXP;
                if (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;

        return cmdr;
}

static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(500);

        /*
         * 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)) {
                while (mci_readl(host, STATUS) & SDMMC_STATUS_BUSY) {
                        if (time_after(jiffies, timeout)) {
                                /* Command will fail; we'll pass error then */
                                dev_err(host->dev, "Busy; trying anyway\n");
                                break;
                        }
                        udelay(10);
                }
        }
}

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);
}

static inline void send_stop_abort(struct dw_mci *host, struct mmc_data *data)
{
        struct mmc_command *stop = data->stop ? data->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 int dw_mci_get_dma_dir(struct mmc_data *data)
{
        if (data->flags & MMC_DATA_WRITE)
                return DMA_TO_DEVICE;
        else
                return DMA_FROM_DEVICE;
}

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

        if (data)
                if (!data->host_cookie)
                        dma_unmap_sg(host->dev,
                                     data->sg,
                                     data->sg_len,
                                     dw_mci_get_dma_dir(data));
}

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->cur_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 void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
                                    unsigned int sg_len)
{
        unsigned int desc_len;
        int i;

        if (host->dma_64bit_address == 1) {
                struct idmac_desc_64addr *desc_first, *desc_last, *desc;

                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;

                                /*
                                 * 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;

        } else {
                struct idmac_desc *desc_first, *desc_last, *desc;

                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;

                                /*
                                 * 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);
        }

        wmb(); /* drain writebuffer */
}

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

        dw_mci_translate_sglist(host, host->data, sg_len);

        /* 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);

        return 0;
}

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 = PAGE_SIZE / 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->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 = PAGE_SIZE / 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->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 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;
        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->cur_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,
                                   bool next)
{
        struct scatterlist *sg;
        unsigned int i, sg_len;

        if (!next && data->host_cookie)
                return data->host_cookie;

        /*
         * 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,
                            dw_mci_get_dma_dir(data));
        if (sg_len == 0)
                return -EINVAL;

        if (next)
                data->host_cookie = sg_len;

        return sg_len;
}

static void dw_mci_pre_req(struct mmc_host *mmc,
                           struct mmc_request *mrq,
                           bool is_first_req)
{
        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) {
                data->host_cookie = 0;
                return;
        }

        if (dw_mci_pre_dma_transfer(slot->host, mrq->data, 1) < 0)
                data->host_cookie = 0;
}

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)
                dma_unmap_sg(slot->host->dev,
                             data->sg,
                             data->sg_len,
                             dw_mci_get_dma_dir(data));
        data->host_cookie = 0;
}

static void dw_mci_adjust_fifoth(struct dw_mci *host, struct mmc_data *data)
{
        unsigned int blksz = data->blksz;
        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) {
                msize = 0;
                rx_wmark = 1;
                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_rd_thld(struct dw_mci *host, struct mmc_data *data)
{
        unsigned int blksz = data->blksz;
        u32 blksz_depth, fifo_depth;
        u16 thld_size;

        WARN_ON(!(data->flags & MMC_DATA_READ));

        /*
         * 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)
                return;

        if (host->timing != MMC_TIMING_MMC_HS200 &&
            host->timing != MMC_TIMING_MMC_HS400 &&
            host->timing != MMC_TIMING_UHS_SDR104)
                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_RD_THLD(thld_size, 1));
        return;

disable:
        mci_writel(host, CDTHRCTL, SDMMC_SET_RD_THLD(0, 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, 0);
        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)) {
                /* We can't do DMA */
                dev_err(host->dev, "%s: failed to start DMA.\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;
                dw_mci_ctrl_rd_thld(host, data);
        } else {
                host->dir_status = DW_MCI_SEND_STATUS;
        }

        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 next issued data may be transfered by DMA mode,
                 * prev_blksz should be invalidated.
                 */
                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 mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
{
        struct dw_mci *host = slot->host;
        unsigned long timeout = jiffies + msecs_to_jiffies(500);
        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);

        while (time_before(jiffies, timeout)) {
                cmd_status = mci_readl(host, CMD);
                if (!(cmd_status & SDMMC_CMD_START))
                        return;
        }
        dev_err(&slot->mmc->class_dev,
                "Timeout sending command (cmd %#x arg %#x status %#x)\n",
                cmd, arg, cmd_status);
}

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;

        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 << div) != slot->__clk_old || 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);

                /* 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 clock with reflecting clock dividor */
                slot->__clk_old = clock << div;
        }

        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->cur_slot = slot;
        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);
        }

        if (mrq->stop)
                host->stop_cmdr = dw_mci_prepare_command(slot->mmc, mrq->stop);
        else
                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 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;
        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) {
                set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
                dev_dbg(&mmc->class_dev, "card is present\n");
        } else {
                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_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 mmc_host *mmc, int enb)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        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 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 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,
        .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->cur_slot->mmc;

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

        host->cur_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 = -EIO;
                        }
                } else {
                        /* SDMMC_INT_SBE is included */
                        data->error = -EIO;
                }

                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_ms;

        drto_clks = mci_readl(host, TMOUT) >> 8;
        drto_ms = DIV_ROUND_UP(drto_clks, host->bus_hz / 1000);

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

        mod_timer(&host->dto_timer, jiffies + msecs_to_jiffies(drto_ms));
}

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 (!test_and_clear_bit(EVENT_CMD_COMPLETE,
                                                &host->pending_events))
                                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) {
                                prev_state = state = STATE_SENDING_CMD;
                                __dw_mci_start_request(host, host->cur_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 (data->stop ||
                                    !(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->quirks & DW_MCI_QUIRK_BROKEN_DTO) &&
                                    (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 (data->stop ||
                                    !(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 (!test_and_clear_bit(EVENT_DATA_COMPLETE,
                                                &host->pending_events)) {
                                /*
                                 * If data error interrupt comes but data over
                                 * interrupt doesn't come within the given time.
                                 * in reading data state.
                                 */
                                if ((host->quirks & DW_MCI_QUIRK_BROKEN_DTO) &&
                                    (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 (!test_and_clear_bit(EVENT_CMD_COMPLETE,
                                                &host->pending_events))
                                break;

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

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

                        if (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)
{
        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)
{
        int i;

        for (i = 0; i < host->num_slots; i++) {
                struct dw_mci_slot *slot = host->slot[i];

                if (!slot)
                        continue;

                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;
        int i;

        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)) {
                        unsigned long irqflags;

                        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) {
                        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);
                }

                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) {
                        if (host->quirks & DW_MCI_QUIRK_BROKEN_DTO)
                                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);
                }

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

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

                /* Handle SDIO Interrupts */
                for (i = 0; i < host->num_slots; i++) {
                        struct dw_mci_slot *slot = host->slot[i];

                        if (!slot)
                                continue;

                        if (pending & SDMMC_INT_SDIO(slot->sdio_id)) {
                                mci_writel(host, RINTSTS,
                                           SDMMC_INT_SDIO(slot->sdio_id));
                                mmc_signal_sdio_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);
                        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);
                        host->dma_ops->complete((void *)host);
                }
        }

        return IRQ_HANDLED;
}

#ifdef CONFIG_OF
/* given a slot, find out the device node representing that slot */
static struct device_node *dw_mci_of_find_slot_node(struct dw_mci_slot *slot)
{
        struct device *dev = slot->mmc->parent;
        struct device_node *np;
        const __be32 *addr;
        int len;

        if (!dev || !dev->of_node)
                return NULL;

        for_each_child_of_node(dev->of_node, np) {
                addr = of_get_property(np, "reg", &len);
                if (!addr || (len < sizeof(int)))
                        continue;
                if (be32_to_cpup(addr) == slot->id)
                        return np;
        }
        return NULL;
}

static void dw_mci_slot_of_parse(struct dw_mci_slot *slot)
{
        struct device_node *np = dw_mci_of_find_slot_node(slot);

        if (!np)
                return;

        if (of_property_read_bool(np, "disable-wp")) {
                slot->mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
                dev_warn(slot->mmc->parent,
                        "Slot quirk 'disable-wp' is deprecated\n");
        }
}
#else /* CONFIG_OF */
static void dw_mci_slot_of_parse(struct dw_mci_slot *slot)
{
}
#endif /* CONFIG_OF */

static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
{
        struct mmc_host *mmc;
        struct dw_mci_slot *slot;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int ctrl_id, ret;
        u32 freq[2];

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

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

        mmc->ops = &dw_mci_ops;
        if (of_property_read_u32_array(host->dev->of_node,
                                       "clock-freq-min-max", freq, 2)) {
                mmc->f_min = DW_MCI_FREQ_MIN;
                mmc->f_max = DW_MCI_FREQ_MAX;
        } else {
                mmc->f_min = freq[0];
                mmc->f_max = freq[1];
        }

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

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

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

        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)
                mmc->caps |= drv_data->caps[ctrl_id];

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

        dw_mci_slot_of_parse(slot);

        ret = mmc_of_parse(mmc);
        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, unsigned int id)
{
        /* Debugfs stuff is cleaned up by mmc core */
        mmc_remove_host(slot->mmc);
        slot->host->slot[id] = NULL;
        mmc_free_host(slot->mmc);
}

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

        /*
        * 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, PAGE_SIZE,
                                                   &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 ((of_property_count_strings(np, "dma-names") < 0) ||
                    (!of_find_property(np, "dmas", NULL))) {
                        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 bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset)
{
        unsigned long timeout = jiffies + msecs_to_jiffies(500);
        u32 ctrl;

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

        /* wait till resets clear */
        do {
                ctrl = mci_readl(host, CTRL);
                if (!(ctrl & reset))
                        return true;
        } while (time_before(jiffies, timeout));

        dev_err(host->dev,
                "Timeout resetting block (ctrl reset %#x)\n",
                ctrl & reset);

        return false;
}

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

        /*
         * Reseting 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 using dma we wait for dma_req to clear */
                if (host->use_dma) {
                        unsigned long timeout = jiffies + msecs_to_jiffies(500);
                        u32 status;

                        do {
                                status = mci_readl(host, STATUS);
                                if (!(status & SDMMC_STATUS_DMA_REQ))
                                        break;
                                cpu_relax();
                        } while (time_before(jiffies, timeout));

                        if (status & SDMMC_STATUS_DMA_REQ) {
                                dev_err(host->dev,
                                        "%s: Timeout waiting for dma_req to clear during reset\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 recommended that we reset and reprogram idmac */
                dw_mci_idmac_reset(host);

        ret = true;

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

        return ret;
}

static void dw_mci_cmd11_timer(unsigned long arg)
{
        struct dw_mci *host = (struct dw_mci *)arg;

        if (host->state != STATE_SENDING_CMD11) {
                dev_warn(host->dev, "Unexpected CMD11 timeout\n");
                return;
        }

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

static void dw_mci_dto_timer(unsigned long arg)
{
        struct dw_mci *host = (struct dw_mci *)arg;

        switch (host->state) {
        case STATE_SENDING_DATA:
        case STATE_DATA_BUSY:
                /*
                 * If DTO interrupt does NOT come in sending data state,
                 * we should notify the driver to terminate current transfer
                 * and report a data timeout to the core.
                 */
                host->data_status = SDMMC_INT_DRTO;
                set_bit(EVENT_DATA_ERROR, &host->pending_events);
                set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
                tasklet_schedule(&host->tasklet);
                break;
        default:
                break;
        }
}

#ifdef CONFIG_OF
static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
{
        struct dw_mci_board *pdata;
        struct device *dev = host->dev;
        struct device_node *np = dev->of_node;
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int ret;
        u32 clock_frequency;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);

        /* find out number of slots supported */
        of_property_read_u32(np, "num-slots", &pdata->num_slots);

        if (of_property_read_u32(np, "fifo-depth", &pdata->fifo_depth))
                dev_info(dev,
                         "fifo-depth property not found, using value of FIFOTH register as default\n");

        of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);

        if (!of_property_read_u32(np, "clock-frequency", &clock_frequency))
                pdata->bus_hz = clock_frequency;

        if (drv_data && drv_data->parse_dt) {
                ret = drv_data->parse_dt(host);
                if (ret)
                        return ERR_PTR(ret);
        }

        if (of_find_property(np, "supports-highspeed", NULL)) {
                dev_info(dev, "supports-highspeed property is deprecated.\n");
                pdata->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
        }

        return pdata;
}

#else /* CONFIG_OF */
static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
{
        return ERR_PTR(-EINVAL);
}
#endif /* CONFIG_OF */

static void dw_mci_enable_cd(struct dw_mci *host)
{
        unsigned long irqflags;
        u32 temp;
        int i;
        struct dw_mci_slot *slot;

        /*
         * No need for CD if all slots have a non-error GPIO
         * as well as broken card detection is found.
         */
        for (i = 0; i < host->num_slots; i++) {
                slot = host->slot[i];
                if (slot->mmc->caps & MMC_CAP_NEEDS_POLL)
                        return;

                if (mmc_gpio_get_cd(slot->mmc) < 0)
                        break;
        }
        if (i == host->num_slots)
                return;

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

int dw_mci_probe(struct dw_mci *host)
{
        const struct dw_mci_drv_data *drv_data = host->drv_data;
        int width, i, ret = 0;
        u32 fifo_size;
        int init_slots = 0;

        if (!host->pdata) {
                host->pdata = dw_mci_parse_dt(host);
                if (IS_ERR(host->pdata)) {
                        dev_err(host->dev, "platform data not available\n");
                        return -EINVAL;
                }
        }

        host->biu_clk = devm_clk_get(host->dev, "biu");
        if (IS_ERR(host->biu_clk)) {
                dev_dbg(host->dev, "biu clock not available\n");
        } else {
                ret = clk_prepare_enable(host->biu_clk);
                if (ret) {
                        dev_err(host->dev, "failed to enable biu clock\n");
                        return ret;
                }
        }

        host->ciu_clk = devm_clk_get(host->dev, "ciu");
        if (IS_ERR(host->ciu_clk)) {
                dev_dbg(host->dev, "ciu clock not available\n");
                host->bus_hz = host->pdata->bus_hz;
        } else {
                ret = clk_prepare_enable(host->ciu_clk);
                if (ret) {
                        dev_err(host->dev, "failed to enable ciu clock\n");
                        goto err_clk_biu;
                }

                if (host->pdata->bus_hz) {
                        ret = clk_set_rate(host->ciu_clk, host->pdata->bus_hz);
                        if (ret)
                                dev_warn(host->dev,
                                         "Unable to set bus rate to %uHz\n",
                                         host->pdata->bus_hz);
                }
                host->bus_hz = clk_get_rate(host->ciu_clk);
        }

        if (!host->bus_hz) {
                dev_err(host->dev,
                        "Platform data must supply bus speed\n");
                ret = -ENODEV;
                goto err_clk_ciu;
        }

        if (drv_data && drv_data->init) {
                ret = drv_data->init(host);
                if (ret) {
                        dev_err(host->dev,
                                "implementation specific init failed\n");
                        goto err_clk_ciu;
                }
        }

        setup_timer(&host->cmd11_timer,
                    dw_mci_cmd11_timer, (unsigned long)host);

        host->quirks = host->pdata->quirks;

        if (host->quirks & DW_MCI_QUIRK_BROKEN_DTO)
                setup_timer(&host->dto_timer,
                            dw_mci_dto_timer, (unsigned long)host);

        spin_lock_init(&host->lock);
        spin_lock_init(&host->irq_lock);
        INIT_LIST_HEAD(&host->queue);

        /*
         * Get the host data width - this assumes that HCON has been set with
         * the correct values.
         */
        i = SDMMC_GET_HDATA_WIDTH(mci_readl(host, HCON));
        if (!i) {
                host->push_data = dw_mci_push_data16;
                host->pull_data = dw_mci_pull_data16;
                width = 16;
                host->data_shift = 1;
        } else if (i == 2) {
                host->push_data = dw_mci_push_data64;
                host->pull_data = dw_mci_pull_data64;
                width = 64;
                host->data_shift = 3;
        } else {
                /* Check for a reserved value, and warn if it is */
                WARN((i != 1),
                     "HCON reports a reserved host data width!\n"
                     "Defaulting to 32-bit access.\n");
                host->push_data = dw_mci_push_data32;
                host->pull_data = dw_mci_pull_data32;
                width = 32;
                host->data_shift = 2;
        }

        /* Reset all blocks */
        if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
                ret = -ENODEV;
                goto err_clk_ciu;
        }

        host->dma_ops = host->pdata->dma_ops;
        dw_mci_init_dma(host);

        /* Clear the interrupts for the host controller */
        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

        /* Put in max timeout */
        mci_writel(host, TMOUT, 0xFFFFFFFF);

        /*
         * FIFO threshold settings  RxMark  = fifo_size / 2 - 1,
         *                          Tx Mark = fifo_size / 2 DMA Size = 8
         */
        if (!host->pdata->fifo_depth) {
                /*
                 * Power-on value of RX_WMark is FIFO_DEPTH-1, but this may
                 * have been overwritten by the bootloader, just like we're
                 * about to do, so if you know the value for your hardware, you
                 * should put it in the platform data.
                 */
                fifo_size = mci_readl(host, FIFOTH);
                fifo_size = 1 + ((fifo_size >> 16) & 0xfff);
        } else {
                fifo_size = host->pdata->fifo_depth;
        }
        host->fifo_depth = fifo_size;
        host->fifoth_val =
                SDMMC_SET_FIFOTH(0x2, fifo_size / 2 - 1, fifo_size / 2);
        mci_writel(host, FIFOTH, host->fifoth_val);

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

        /*
         * In 2.40a spec, Data offset is changed.
         * Need to check the version-id and set data-offset for DATA register.
         */
        host->verid = SDMMC_GET_VERID(mci_readl(host, VERID));
        dev_info(host->dev, "Version ID is %04x\n", host->verid);

        if (host->verid < DW_MMC_240A)
                host->fifo_reg = host->regs + DATA_OFFSET;
        else
                host->fifo_reg = host->regs + DATA_240A_OFFSET;

        tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);
        ret = devm_request_irq(host->dev, host->irq, dw_mci_interrupt,
                               host->irq_flags, "dw-mci", host);
        if (ret)
                goto err_dmaunmap;

        if (host->pdata->num_slots)
                host->num_slots = host->pdata->num_slots;
        else
                host->num_slots = 1;

        if (host->num_slots < 1 ||
            host->num_slots > SDMMC_GET_SLOT_NUM(mci_readl(host, HCON))) {
                dev_err(host->dev,
                        "Platform data must supply correct num_slots.\n");
                ret = -ENODEV;
                goto err_clk_ciu;
        }

        /*
         * Enable interrupts for command done, data over, data empty,
         * receive ready and error such as transmit, receive timeout, crc error
         */
        mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
                   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
                   DW_MCI_ERROR_FLAGS);
        /* Enable mci interrupt */
        mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);

        dev_info(host->dev,
                 "DW MMC controller at irq %d,%d bit host data width,%u deep fifo\n",
                 host->irq, width, fifo_size);

        /* We need at least one slot to succeed */
        for (i = 0; i < host->num_slots; i++) {
                ret = dw_mci_init_slot(host, i);
                if (ret)
                        dev_dbg(host->dev, "slot %d init failed\n", i);
                else
                        init_slots++;
        }

        if (init_slots) {
                dev_info(host->dev, "%d slots initialized\n", init_slots);
        } else {
                dev_dbg(host->dev,
                        "attempted to initialize %d slots, but failed on all\n",
                        host->num_slots);
                goto err_dmaunmap;
        }

        /* Now that slots are all setup, we can enable card detect */
        dw_mci_enable_cd(host);

        return 0;

err_dmaunmap:
        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);

err_clk_ciu:
        if (!IS_ERR(host->ciu_clk))
                clk_disable_unprepare(host->ciu_clk);

err_clk_biu:
        if (!IS_ERR(host->biu_clk))
                clk_disable_unprepare(host->biu_clk);

        return ret;
}
EXPORT_SYMBOL(dw_mci_probe);

void dw_mci_remove(struct dw_mci *host)
{
        int i;

        for (i = 0; i < host->num_slots; i++) {
                dev_dbg(host->dev, "remove slot %d\n", i);
                if (host->slot[i])
                        dw_mci_cleanup_slot(host->slot[i], i);
        }

        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */

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

        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);

        if (!IS_ERR(host->ciu_clk))
                clk_disable_unprepare(host->ciu_clk);

        if (!IS_ERR(host->biu_clk))
                clk_disable_unprepare(host->biu_clk);
}
EXPORT_SYMBOL(dw_mci_remove);



#ifdef CONFIG_PM_SLEEP
/*
 * TODO: we should probably disable the clock to the card in the suspend path.
 */
int dw_mci_suspend(struct dw_mci *host)
{
        if (host->use_dma && host->dma_ops->exit)
                host->dma_ops->exit(host);

        return 0;
}
EXPORT_SYMBOL(dw_mci_suspend);

int dw_mci_resume(struct dw_mci *host)
{
        int i, ret;

        if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
                ret = -ENODEV;
                return ret;
        }

        if (host->use_dma && host->dma_ops->init)
                host->dma_ops->init(host);

        /*
         * Restore the initial value at FIFOTH register
         * And Invalidate the prev_blksz with zero
         */
        mci_writel(host, FIFOTH, host->fifoth_val);
        host->prev_blksz = 0;

        /* Put in max timeout */
        mci_writel(host, TMOUT, 0xFFFFFFFF);

        mci_writel(host, RINTSTS, 0xFFFFFFFF);
        mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
                   SDMMC_INT_TXDR | SDMMC_INT_RXDR |
                   DW_MCI_ERROR_FLAGS);
        mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);

        for (i = 0; i < host->num_slots; i++) {
                struct dw_mci_slot *slot = host->slot[i];

                if (!slot)
                        continue;
                if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) {
                        dw_mci_set_ios(slot->mmc, &slot->mmc->ios);
                        dw_mci_setup_bus(slot, true);
                }
        }

        /* Now that slots are all setup, we can enable card detect */
        dw_mci_enable_cd(host);

        return 0;
}
EXPORT_SYMBOL(dw_mci_resume);
#endif /* CONFIG_PM_SLEEP */

static int __init dw_mci_init(void)
{
        pr_info("Synopsys Designware Multimedia Card Interface Driver\n");
        return 0;
}

static void __exit dw_mci_exit(void)
{
}

module_init(dw_mci_init);
module_exit(dw_mci_exit);

MODULE_DESCRIPTION("DW Multimedia Card Interface driver");
MODULE_AUTHOR("NXP Semiconductor VietNam");
MODULE_AUTHOR("Imagination Technologies Ltd");
MODULE_LICENSE("GPL v2");