mmc: sdhci: add quirk for broken HS200 support

[karo-tx-linux.git] / drivers / mmc / host / sdhci.c

/*
 *  linux/drivers/mmc/host/sdhci.c - Secure Digital Host Controller Interface driver
 *
 *  Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
 *
 * 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.
 *
 * Thanks to the following companies for their support:
 *
 *     - JMicron (hardware and technical support)
 */

#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>

#include <linux/leds.h>

#include <linux/mmc/mmc.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/slot-gpio.h>

#include "sdhci.h"

#define DRIVER_NAME "sdhci"

#define DBG(f, x...) \
        pr_debug(DRIVER_NAME " [%s()]: " f, __func__,## x)

#if defined(CONFIG_LEDS_CLASS) || (defined(CONFIG_LEDS_CLASS_MODULE) && \
        defined(CONFIG_MMC_SDHCI_MODULE))
#define SDHCI_USE_LEDS_CLASS
#endif

#define MAX_TUNING_LOOP 40

static unsigned int debug_quirks = 0;
static unsigned int debug_quirks2;

static void sdhci_finish_data(struct sdhci_host *);

static void sdhci_finish_command(struct sdhci_host *);
static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
static void sdhci_tuning_timer(unsigned long data);
static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);

#ifdef CONFIG_PM_RUNTIME
static int sdhci_runtime_pm_get(struct sdhci_host *host);
static int sdhci_runtime_pm_put(struct sdhci_host *host);
static void sdhci_runtime_pm_bus_on(struct sdhci_host *host);
static void sdhci_runtime_pm_bus_off(struct sdhci_host *host);
#else
static inline int sdhci_runtime_pm_get(struct sdhci_host *host)
{
        return 0;
}
static inline int sdhci_runtime_pm_put(struct sdhci_host *host)
{
        return 0;
}
static void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
{
}
static void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
{
}
#endif

static void sdhci_dumpregs(struct sdhci_host *host)
{
        pr_debug(DRIVER_NAME ": =========== REGISTER DUMP (%s)===========\n",
                mmc_hostname(host->mmc));

        pr_debug(DRIVER_NAME ": Sys addr: 0x%08x | Version:  0x%08x\n",
                sdhci_readl(host, SDHCI_DMA_ADDRESS),
                sdhci_readw(host, SDHCI_HOST_VERSION));
        pr_debug(DRIVER_NAME ": Blk size: 0x%08x | Blk cnt:  0x%08x\n",
                sdhci_readw(host, SDHCI_BLOCK_SIZE),
                sdhci_readw(host, SDHCI_BLOCK_COUNT));
        pr_debug(DRIVER_NAME ": Argument: 0x%08x | Trn mode: 0x%08x\n",
                sdhci_readl(host, SDHCI_ARGUMENT),
                sdhci_readw(host, SDHCI_TRANSFER_MODE));
        pr_debug(DRIVER_NAME ": Present:  0x%08x | Host ctl: 0x%08x\n",
                sdhci_readl(host, SDHCI_PRESENT_STATE),
                sdhci_readb(host, SDHCI_HOST_CONTROL));
        pr_debug(DRIVER_NAME ": Power:    0x%08x | Blk gap:  0x%08x\n",
                sdhci_readb(host, SDHCI_POWER_CONTROL),
                sdhci_readb(host, SDHCI_BLOCK_GAP_CONTROL));
        pr_debug(DRIVER_NAME ": Wake-up:  0x%08x | Clock:    0x%08x\n",
                sdhci_readb(host, SDHCI_WAKE_UP_CONTROL),
                sdhci_readw(host, SDHCI_CLOCK_CONTROL));
        pr_debug(DRIVER_NAME ": Timeout:  0x%08x | Int stat: 0x%08x\n",
                sdhci_readb(host, SDHCI_TIMEOUT_CONTROL),
                sdhci_readl(host, SDHCI_INT_STATUS));
        pr_debug(DRIVER_NAME ": Int enab: 0x%08x | Sig enab: 0x%08x\n",
                sdhci_readl(host, SDHCI_INT_ENABLE),
                sdhci_readl(host, SDHCI_SIGNAL_ENABLE));
        pr_debug(DRIVER_NAME ": AC12 err: 0x%08x | Slot int: 0x%08x\n",
                sdhci_readw(host, SDHCI_ACMD12_ERR),
                sdhci_readw(host, SDHCI_SLOT_INT_STATUS));
        pr_debug(DRIVER_NAME ": Caps:     0x%08x | Caps_1:   0x%08x\n",
                sdhci_readl(host, SDHCI_CAPABILITIES),
                sdhci_readl(host, SDHCI_CAPABILITIES_1));
        pr_debug(DRIVER_NAME ": Cmd:      0x%08x | Max curr: 0x%08x\n",
                sdhci_readw(host, SDHCI_COMMAND),
                sdhci_readl(host, SDHCI_MAX_CURRENT));
        pr_debug(DRIVER_NAME ": Host ctl2: 0x%08x\n",
                sdhci_readw(host, SDHCI_HOST_CONTROL2));

        if (host->flags & SDHCI_USE_ADMA)
                pr_debug(DRIVER_NAME ": ADMA Err: 0x%08x | ADMA Ptr: 0x%08x\n",
                       readl(host->ioaddr + SDHCI_ADMA_ERROR),
                       readl(host->ioaddr + SDHCI_ADMA_ADDRESS));

        pr_debug(DRIVER_NAME ": ===========================================\n");
}

/*****************************************************************************\
 *                                                                           *
 * Low level functions                                                       *
 *                                                                           *
\*****************************************************************************/

static void sdhci_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
{
        u32 ier;

        ier = sdhci_readl(host, SDHCI_INT_ENABLE);
        ier &= ~clear;
        ier |= set;
        sdhci_writel(host, ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
}

static void sdhci_unmask_irqs(struct sdhci_host *host, u32 irqs)
{
        sdhci_clear_set_irqs(host, 0, irqs);
}

static void sdhci_mask_irqs(struct sdhci_host *host, u32 irqs)
{
        sdhci_clear_set_irqs(host, irqs, 0);
}

static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
{
        u32 present, irqs;

        if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
            (host->mmc->caps & MMC_CAP_NONREMOVABLE))
                return;

        present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
                              SDHCI_CARD_PRESENT;
        irqs = present ? SDHCI_INT_CARD_REMOVE : SDHCI_INT_CARD_INSERT;

        if (enable)
                sdhci_unmask_irqs(host, irqs);
        else
                sdhci_mask_irqs(host, irqs);
}

static void sdhci_enable_card_detection(struct sdhci_host *host)
{
        sdhci_set_card_detection(host, true);
}

static void sdhci_disable_card_detection(struct sdhci_host *host)
{
        sdhci_set_card_detection(host, false);
}

static void sdhci_reset(struct sdhci_host *host, u8 mask)
{
        unsigned long timeout;
        u32 uninitialized_var(ier);

        if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
                if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
                        SDHCI_CARD_PRESENT))
                        return;
        }

        if (host->quirks & SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
                ier = sdhci_readl(host, SDHCI_INT_ENABLE);

        if (host->ops->platform_reset_enter)
                host->ops->platform_reset_enter(host, mask);

        sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);

        if (mask & SDHCI_RESET_ALL) {
                host->clock = 0;
                /* Reset-all turns off SD Bus Power */
                if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
                        sdhci_runtime_pm_bus_off(host);
        }

        /* Wait max 100 ms */
        timeout = 100;

        /* hw clears the bit when it's done */
        while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) {
                if (timeout == 0) {
                        pr_err("%s: Reset 0x%x never completed.\n",
                                mmc_hostname(host->mmc), (int)mask);
                        sdhci_dumpregs(host);
                        return;
                }
                timeout--;
                mdelay(1);
        }

        if (host->ops->platform_reset_exit)
                host->ops->platform_reset_exit(host, mask);

        if (host->quirks & SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
                sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK, ier);

        if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
                if ((host->ops->enable_dma) && (mask & SDHCI_RESET_ALL))
                        host->ops->enable_dma(host);
        }
}

static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);

static void sdhci_init(struct sdhci_host *host, int soft)
{
        if (soft)
                sdhci_reset(host, SDHCI_RESET_CMD|SDHCI_RESET_DATA);
        else
                sdhci_reset(host, SDHCI_RESET_ALL);

        sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK,
                SDHCI_INT_BUS_POWER | SDHCI_INT_DATA_END_BIT |
                SDHCI_INT_DATA_CRC | SDHCI_INT_DATA_TIMEOUT | SDHCI_INT_INDEX |
                SDHCI_INT_END_BIT | SDHCI_INT_CRC | SDHCI_INT_TIMEOUT |
                SDHCI_INT_DATA_END | SDHCI_INT_RESPONSE);

        if (soft) {
                /* force clock reconfiguration */
                host->clock = 0;
                sdhci_set_ios(host->mmc, &host->mmc->ios);
        }
}

static void sdhci_reinit(struct sdhci_host *host)
{
        sdhci_init(host, 0);
        /*
         * Retuning stuffs are affected by different cards inserted and only
         * applicable to UHS-I cards. So reset these fields to their initial
         * value when card is removed.
         */
        if (host->flags & SDHCI_USING_RETUNING_TIMER) {
                host->flags &= ~SDHCI_USING_RETUNING_TIMER;

                del_timer_sync(&host->tuning_timer);
                host->flags &= ~SDHCI_NEEDS_RETUNING;
                host->mmc->max_blk_count =
                        (host->quirks & SDHCI_QUIRK_NO_MULTIBLOCK) ? 1 : 65535;
        }
        sdhci_enable_card_detection(host);
}

static void sdhci_activate_led(struct sdhci_host *host)
{
        u8 ctrl;

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
        ctrl |= SDHCI_CTRL_LED;
        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}

static void sdhci_deactivate_led(struct sdhci_host *host)
{
        u8 ctrl;

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
        ctrl &= ~SDHCI_CTRL_LED;
        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}

#ifdef SDHCI_USE_LEDS_CLASS
static void sdhci_led_control(struct led_classdev *led,
        enum led_brightness brightness)
{
        struct sdhci_host *host = container_of(led, struct sdhci_host, led);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);

        if (host->runtime_suspended)
                goto out;

        if (brightness == LED_OFF)
                sdhci_deactivate_led(host);
        else
                sdhci_activate_led(host);
out:
        spin_unlock_irqrestore(&host->lock, flags);
}
#endif

/*****************************************************************************\
 *                                                                           *
 * Core functions                                                            *
 *                                                                           *
\*****************************************************************************/

static void sdhci_read_block_pio(struct sdhci_host *host)
{
        unsigned long flags;
        size_t blksize, len, chunk;
        u32 uninitialized_var(scratch);
        u8 *buf;

        DBG("PIO reading\n");

        blksize = host->data->blksz;
        chunk = 0;

        local_irq_save(flags);

        while (blksize) {
                if (!sg_miter_next(&host->sg_miter))
                        BUG();

                len = min(host->sg_miter.length, blksize);

                blksize -= len;
                host->sg_miter.consumed = len;

                buf = host->sg_miter.addr;

                while (len) {
                        if (chunk == 0) {
                                scratch = sdhci_readl(host, SDHCI_BUFFER);
                                chunk = 4;
                        }

                        *buf = scratch & 0xFF;

                        buf++;
                        scratch >>= 8;
                        chunk--;
                        len--;
                }
        }

        sg_miter_stop(&host->sg_miter);

        local_irq_restore(flags);
}

static void sdhci_write_block_pio(struct sdhci_host *host)
{
        unsigned long flags;
        size_t blksize, len, chunk;
        u32 scratch;
        u8 *buf;

        DBG("PIO writing\n");

        blksize = host->data->blksz;
        chunk = 0;
        scratch = 0;

        local_irq_save(flags);

        while (blksize) {
                if (!sg_miter_next(&host->sg_miter))
                        BUG();

                len = min(host->sg_miter.length, blksize);

                blksize -= len;
                host->sg_miter.consumed = len;

                buf = host->sg_miter.addr;

                while (len) {
                        scratch |= (u32)*buf << (chunk * 8);

                        buf++;
                        chunk++;
                        len--;

                        if ((chunk == 4) || ((len == 0) && (blksize == 0))) {
                                sdhci_writel(host, scratch, SDHCI_BUFFER);
                                chunk = 0;
                                scratch = 0;
                        }
                }
        }

        sg_miter_stop(&host->sg_miter);

        local_irq_restore(flags);
}

static void sdhci_transfer_pio(struct sdhci_host *host)
{
        u32 mask;

        BUG_ON(!host->data);

        if (host->blocks == 0)
                return;

        if (host->data->flags & MMC_DATA_READ)
                mask = SDHCI_DATA_AVAILABLE;
        else
                mask = SDHCI_SPACE_AVAILABLE;

        /*
         * Some controllers (JMicron JMB38x) mess up the buffer bits
         * for transfers < 4 bytes. As long as it is just one block,
         * we can ignore the bits.
         */
        if ((host->quirks & SDHCI_QUIRK_BROKEN_SMALL_PIO) &&
                (host->data->blocks == 1))
                mask = ~0;

        while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) {
                if (host->quirks & SDHCI_QUIRK_PIO_NEEDS_DELAY)
                        udelay(100);

                if (host->data->flags & MMC_DATA_READ)
                        sdhci_read_block_pio(host);
                else
                        sdhci_write_block_pio(host);

                host->blocks--;
                if (host->blocks == 0)
                        break;
        }

        DBG("PIO transfer complete.\n");
}

static char *sdhci_kmap_atomic(struct scatterlist *sg, unsigned long *flags)
{
        local_irq_save(*flags);
        return kmap_atomic(sg_page(sg)) + sg->offset;
}

static void sdhci_kunmap_atomic(void *buffer, unsigned long *flags)
{
        kunmap_atomic(buffer);
        local_irq_restore(*flags);
}

static void sdhci_set_adma_desc(u8 *desc, u32 addr, int len, unsigned cmd)
{
        __le32 *dataddr = (__le32 __force *)(desc + 4);
        __le16 *cmdlen = (__le16 __force *)desc;

        /* SDHCI specification says ADMA descriptors should be 4 byte
         * aligned, so using 16 or 32bit operations should be safe. */

        cmdlen[0] = cpu_to_le16(cmd);
        cmdlen[1] = cpu_to_le16(len);

        dataddr[0] = cpu_to_le32(addr);
}

static int sdhci_adma_table_pre(struct sdhci_host *host,
        struct mmc_data *data)
{
        int direction;

        u8 *desc;
        u8 *align;
        dma_addr_t addr;
        dma_addr_t align_addr;
        int len, offset;

        struct scatterlist *sg;
        int i;
        char *buffer;
        unsigned long flags;

        /*
         * The spec does not specify endianness of descriptor table.
         * We currently guess that it is LE.
         */

        if (data->flags & MMC_DATA_READ)
                direction = DMA_FROM_DEVICE;
        else
                direction = DMA_TO_DEVICE;

        /*
         * The ADMA descriptor table is mapped further down as we
         * need to fill it with data first.
         */

        host->align_addr = dma_map_single(mmc_dev(host->mmc),
                host->align_buffer, 128 * 4, direction);
        if (dma_mapping_error(mmc_dev(host->mmc), host->align_addr))
                goto fail;
        BUG_ON(host->align_addr & 0x3);

        host->sg_count = dma_map_sg(mmc_dev(host->mmc),
                data->sg, data->sg_len, direction);
        if (host->sg_count == 0)
                goto unmap_align;

        desc = host->adma_desc;
        align = host->align_buffer;

        align_addr = host->align_addr;

        for_each_sg(data->sg, sg, host->sg_count, i) {
                addr = sg_dma_address(sg);
                len = sg_dma_len(sg);

                /*
                 * The SDHCI specification states that ADMA
                 * addresses must be 32-bit aligned. If they
                 * aren't, then we use a bounce buffer for
                 * the (up to three) bytes that screw up the
                 * alignment.
                 */
                offset = (4 - (addr & 0x3)) & 0x3;
                if (offset) {
                        if (data->flags & MMC_DATA_WRITE) {
                                buffer = sdhci_kmap_atomic(sg, &flags);
                                WARN_ON(((long)buffer & PAGE_MASK) > (PAGE_SIZE - 3));
                                memcpy(align, buffer, offset);
                                sdhci_kunmap_atomic(buffer, &flags);
                        }

                        /* tran, valid */
                        sdhci_set_adma_desc(desc, align_addr, offset, 0x21);

                        BUG_ON(offset > 65536);

                        align += 4;
                        align_addr += 4;

                        desc += 8;

                        addr += offset;
                        len -= offset;
                }

                BUG_ON(len > 65536);

                /* tran, valid */
                sdhci_set_adma_desc(desc, addr, len, 0x21);
                desc += 8;

                /*
                 * If this triggers then we have a calculation bug
                 * somewhere. :/
                 */
                WARN_ON((desc - host->adma_desc) > (128 * 2 + 1) * 4);
        }

        if (host->quirks & SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC) {
                /*
                * Mark the last descriptor as the terminating descriptor
                */
                if (desc != host->adma_desc) {
                        desc -= 8;
                        desc[0] |= 0x2; /* end */
                }
        } else {
                /*
                * Add a terminating entry.
                */

                /* nop, end, valid */
                sdhci_set_adma_desc(desc, 0, 0, 0x3);
        }

        /*
         * Resync align buffer as we might have changed it.
         */
        if (data->flags & MMC_DATA_WRITE) {
                dma_sync_single_for_device(mmc_dev(host->mmc),
                        host->align_addr, 128 * 4, direction);
        }

        host->adma_addr = dma_map_single(mmc_dev(host->mmc),
                host->adma_desc, (128 * 2 + 1) * 4, DMA_TO_DEVICE);
        if (dma_mapping_error(mmc_dev(host->mmc), host->adma_addr))
                goto unmap_entries;
        BUG_ON(host->adma_addr & 0x3);

        return 0;

unmap_entries:
        dma_unmap_sg(mmc_dev(host->mmc), data->sg,
                data->sg_len, direction);
unmap_align:
        dma_unmap_single(mmc_dev(host->mmc), host->align_addr,
                128 * 4, direction);
fail:
        return -EINVAL;
}

static void sdhci_adma_table_post(struct sdhci_host *host,
        struct mmc_data *data)
{
        int direction;

        struct scatterlist *sg;
        int i, size;
        u8 *align;
        char *buffer;
        unsigned long flags;

        if (data->flags & MMC_DATA_READ)
                direction = DMA_FROM_DEVICE;
        else
                direction = DMA_TO_DEVICE;

        dma_unmap_single(mmc_dev(host->mmc), host->adma_addr,
                (128 * 2 + 1) * 4, DMA_TO_DEVICE);

        dma_unmap_single(mmc_dev(host->mmc), host->align_addr,
                128 * 4, direction);

        if (data->flags & MMC_DATA_READ) {
                dma_sync_sg_for_cpu(mmc_dev(host->mmc), data->sg,
                        data->sg_len, direction);

                align = host->align_buffer;

                for_each_sg(data->sg, sg, host->sg_count, i) {
                        if (sg_dma_address(sg) & 0x3) {
                                size = 4 - (sg_dma_address(sg) & 0x3);

                                buffer = sdhci_kmap_atomic(sg, &flags);
                                WARN_ON(((long)buffer & PAGE_MASK) > (PAGE_SIZE - 3));
                                memcpy(buffer, align, size);
                                sdhci_kunmap_atomic(buffer, &flags);

                                align += 4;
                        }
                }
        }

        dma_unmap_sg(mmc_dev(host->mmc), data->sg,
                data->sg_len, direction);
}

static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
        u8 count;
        struct mmc_data *data = cmd->data;
        unsigned target_timeout, current_timeout;

        /*
         * If the host controller provides us with an incorrect timeout
         * value, just skip the check and use 0xE.  The hardware may take
         * longer to time out, but that's much better than having a too-short
         * timeout value.
         */
        if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
                return 0xE;

        /* Unspecified timeout, assume max */
        if (!data && !cmd->cmd_timeout_ms)
                return 0xE;

        /* timeout in us */
        if (!data)
                target_timeout = cmd->cmd_timeout_ms * 1000;
        else {
                target_timeout = data->timeout_ns / 1000;
                if (host->clock)
                        target_timeout += data->timeout_clks / host->clock;
        }

        /*
         * Figure out needed cycles.
         * We do this in steps in order to fit inside a 32 bit int.
         * The first step is the minimum timeout, which will have a
         * minimum resolution of 6 bits:
         * (1) 2^13*1000 > 2^22,
         * (2) host->timeout_clk < 2^16
         *     =>
         *     (1) / (2) > 2^6
         */
        count = 0;
        current_timeout = (1 << 13) * 1000 / host->timeout_clk;
        while (current_timeout < target_timeout) {
                count++;
                current_timeout <<= 1;
                if (count >= 0xF)
                        break;
        }

        if (count >= 0xF) {
                DBG("%s: Too large timeout 0x%x requested for CMD%d!\n",
                    mmc_hostname(host->mmc), count, cmd->opcode);
                count = 0xE;
        }

        return count;
}

static void sdhci_set_transfer_irqs(struct sdhci_host *host)
{
        u32 pio_irqs = SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL;
        u32 dma_irqs = SDHCI_INT_DMA_END | SDHCI_INT_ADMA_ERROR;

        if (host->flags & SDHCI_REQ_USE_DMA)
                sdhci_clear_set_irqs(host, pio_irqs, dma_irqs);
        else
                sdhci_clear_set_irqs(host, dma_irqs, pio_irqs);
}

static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
{
        u8 count;
        u8 ctrl;
        struct mmc_data *data = cmd->data;
        int ret;

        WARN_ON(host->data);

        if (data || (cmd->flags & MMC_RSP_BUSY)) {
                count = sdhci_calc_timeout(host, cmd);
                sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
        }

        if (!data)
                return;

        /* Sanity checks */
        BUG_ON(data->blksz * data->blocks > 524288);
        BUG_ON(data->blksz > host->mmc->max_blk_size);
        BUG_ON(data->blocks > 65535);

        host->data = data;
        host->data_early = 0;
        host->data->bytes_xfered = 0;

        if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA))
                host->flags |= SDHCI_REQ_USE_DMA;

        /*
         * FIXME: This doesn't account for merging when mapping the
         * scatterlist.
         */
        if (host->flags & SDHCI_REQ_USE_DMA) {
                int broken, i;
                struct scatterlist *sg;

                broken = 0;
                if (host->flags & SDHCI_USE_ADMA) {
                        if (host->quirks & SDHCI_QUIRK_32BIT_ADMA_SIZE)
                                broken = 1;
                } else {
                        if (host->quirks & SDHCI_QUIRK_32BIT_DMA_SIZE)
                                broken = 1;
                }

                if (unlikely(broken)) {
                        for_each_sg(data->sg, sg, data->sg_len, i) {
                                if (sg->length & 0x3) {
                                        DBG("Reverting to PIO because of "
                                                "transfer size (%d)\n",
                                                sg->length);
                                        host->flags &= ~SDHCI_REQ_USE_DMA;
                                        break;
                                }
                        }
                }
        }

        /*
         * The assumption here being that alignment is the same after
         * translation to device address space.
         */
        if (host->flags & SDHCI_REQ_USE_DMA) {
                int broken, i;
                struct scatterlist *sg;

                broken = 0;
                if (host->flags & SDHCI_USE_ADMA) {
                        /*
                         * As we use 3 byte chunks to work around
                         * alignment problems, we need to check this
                         * quirk.
                         */
                        if (host->quirks & SDHCI_QUIRK_32BIT_ADMA_SIZE)
                                broken = 1;
                } else {
                        if (host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR)
                                broken = 1;
                }

                if (unlikely(broken)) {
                        for_each_sg(data->sg, sg, data->sg_len, i) {
                                if (sg->offset & 0x3) {
                                        DBG("Reverting to PIO because of "
                                                "bad alignment\n");
                                        host->flags &= ~SDHCI_REQ_USE_DMA;
                                        break;
                                }
                        }
                }
        }

        if (host->flags & SDHCI_REQ_USE_DMA) {
                if (host->flags & SDHCI_USE_ADMA) {
                        ret = sdhci_adma_table_pre(host, data);
                        if (ret) {
                                /*
                                 * This only happens when someone fed
                                 * us an invalid request.
                                 */
                                WARN_ON(1);
                                host->flags &= ~SDHCI_REQ_USE_DMA;
                        } else {
                                sdhci_writel(host, host->adma_addr,
                                        SDHCI_ADMA_ADDRESS);
                        }
                } else {
                        int sg_cnt;

                        sg_cnt = dma_map_sg(mmc_dev(host->mmc),
                                        data->sg, data->sg_len,
                                        (data->flags & MMC_DATA_READ) ?
                                                DMA_FROM_DEVICE :
                                                DMA_TO_DEVICE);
                        if (sg_cnt == 0) {
                                /*
                                 * This only happens when someone fed
                                 * us an invalid request.
                                 */
                                WARN_ON(1);
                                host->flags &= ~SDHCI_REQ_USE_DMA;
                        } else {
                                WARN_ON(sg_cnt != 1);
                                sdhci_writel(host, sg_dma_address(data->sg),
                                        SDHCI_DMA_ADDRESS);
                        }
                }
        }

        /*
         * Always adjust the DMA selection as some controllers
         * (e.g. JMicron) can't do PIO properly when the selection
         * is ADMA.
         */
        if (host->version >= SDHCI_SPEC_200) {
                ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
                ctrl &= ~SDHCI_CTRL_DMA_MASK;
                if ((host->flags & SDHCI_REQ_USE_DMA) &&
                        (host->flags & SDHCI_USE_ADMA))
                        ctrl |= SDHCI_CTRL_ADMA32;
                else
                        ctrl |= SDHCI_CTRL_SDMA;
                sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
        }

        if (!(host->flags & SDHCI_REQ_USE_DMA)) {
                int flags;

                flags = SG_MITER_ATOMIC;
                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->blocks = data->blocks;
        }

        sdhci_set_transfer_irqs(host);

        /* Set the DMA boundary value and block size */
        sdhci_writew(host, SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG,
                data->blksz), SDHCI_BLOCK_SIZE);
        sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
}

static void sdhci_set_transfer_mode(struct sdhci_host *host,
        struct mmc_command *cmd)
{
        u16 mode;
        struct mmc_data *data = cmd->data;

        if (data == NULL) {
                /* clear Auto CMD settings for no data CMDs */
                mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
                sdhci_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
                                SDHCI_TRNS_AUTO_CMD23), SDHCI_TRANSFER_MODE);
                return;
        }

        WARN_ON(!host->data);

        mode = SDHCI_TRNS_BLK_CNT_EN;
        if (mmc_op_multi(cmd->opcode) || data->blocks > 1) {
                mode |= SDHCI_TRNS_MULTI;
                /*
                 * If we are sending CMD23, CMD12 never gets sent
                 * on successful completion (so no Auto-CMD12).
                 */
                if (!host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD12))
                        mode |= SDHCI_TRNS_AUTO_CMD12;
                else if (host->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
                        mode |= SDHCI_TRNS_AUTO_CMD23;
                        sdhci_writel(host, host->mrq->sbc->arg, SDHCI_ARGUMENT2);
                }
        }

        if (data->flags & MMC_DATA_READ)
                mode |= SDHCI_TRNS_READ;
        if (host->flags & SDHCI_REQ_USE_DMA)
                mode |= SDHCI_TRNS_DMA;

        sdhci_writew(host, mode, SDHCI_TRANSFER_MODE);
}

static void sdhci_finish_data(struct sdhci_host *host)
{
        struct mmc_data *data;

        BUG_ON(!host->data);

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

        if (host->flags & SDHCI_REQ_USE_DMA) {
                if (host->flags & SDHCI_USE_ADMA)
                        sdhci_adma_table_post(host, data);
                else {
                        dma_unmap_sg(mmc_dev(host->mmc), data->sg,
                                data->sg_len, (data->flags & MMC_DATA_READ) ?
                                        DMA_FROM_DEVICE : DMA_TO_DEVICE);
                }
        }

        /*
         * The specification states that the block count register must
         * be updated, but it does not specify at what point in the
         * data flow. That makes the register entirely useless to read
         * back so we have to assume that nothing made it to the card
         * in the event of an error.
         */
        if (data->error)
                data->bytes_xfered = 0;
        else
                data->bytes_xfered = data->blksz * data->blocks;

        /*
         * Need to send CMD12 if -
         * a) open-ended multiblock transfer (no CMD23)
         * b) error in multiblock transfer
         */
        if (data->stop &&
            (data->error ||
             !host->mrq->sbc)) {

                /*
                 * The controller needs a reset of internal state machines
                 * upon error conditions.
                 */
                if (data->error) {
                        sdhci_reset(host, SDHCI_RESET_CMD);
                        sdhci_reset(host, SDHCI_RESET_DATA);
                }

                sdhci_send_command(host, data->stop);
        } else
                tasklet_schedule(&host->finish_tasklet);
}

void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
{
        int flags;
        u32 mask;
        unsigned long timeout;

        WARN_ON(host->cmd);

        /* Wait max 10 ms */
        timeout = 10;

        mask = SDHCI_CMD_INHIBIT;
        if ((cmd->data != NULL) || (cmd->flags & MMC_RSP_BUSY))
                mask |= SDHCI_DATA_INHIBIT;

        /* We shouldn't wait for data inihibit for stop commands, even
           though they might use busy signaling */
        if (host->mrq->data && (cmd == host->mrq->data->stop))
                mask &= ~SDHCI_DATA_INHIBIT;

        while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) {
                if (timeout == 0) {
                        pr_err("%s: Controller never released "
                                "inhibit bit(s).\n", mmc_hostname(host->mmc));
                        sdhci_dumpregs(host);
                        cmd->error = -EIO;
                        tasklet_schedule(&host->finish_tasklet);
                        return;
                }
                timeout--;
                mdelay(1);
        }

        mod_timer(&host->timer, jiffies + 10 * HZ);

        host->cmd = cmd;

        sdhci_prepare_data(host, cmd);

        sdhci_writel(host, cmd->arg, SDHCI_ARGUMENT);

        sdhci_set_transfer_mode(host, cmd);

        if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
                pr_err("%s: Unsupported response type!\n",
                        mmc_hostname(host->mmc));
                cmd->error = -EINVAL;
                tasklet_schedule(&host->finish_tasklet);
                return;
        }

        if (!(cmd->flags & MMC_RSP_PRESENT))
                flags = SDHCI_CMD_RESP_NONE;
        else if (cmd->flags & MMC_RSP_136)
                flags = SDHCI_CMD_RESP_LONG;
        else if (cmd->flags & MMC_RSP_BUSY)
                flags = SDHCI_CMD_RESP_SHORT_BUSY;
        else
                flags = SDHCI_CMD_RESP_SHORT;

        if (cmd->flags & MMC_RSP_CRC)
                flags |= SDHCI_CMD_CRC;
        if (cmd->flags & MMC_RSP_OPCODE)
                flags |= SDHCI_CMD_INDEX;

        /* CMD19 is special in that the Data Present Select should be set */
        if (cmd->data || cmd->opcode == MMC_SEND_TUNING_BLOCK ||
            cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200)
                flags |= SDHCI_CMD_DATA;

        sdhci_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), SDHCI_COMMAND);
}
EXPORT_SYMBOL_GPL(sdhci_send_command);

static void sdhci_finish_command(struct sdhci_host *host)
{
        int i;

        BUG_ON(host->cmd == NULL);

        if (host->cmd->flags & MMC_RSP_PRESENT) {
                if (host->cmd->flags & MMC_RSP_136) {
                        /* CRC is stripped so we need to do some shifting. */
                        for (i = 0;i < 4;i++) {
                                host->cmd->resp[i] = sdhci_readl(host,
                                        SDHCI_RESPONSE + (3-i)*4) << 8;
                                if (i != 3)
                                        host->cmd->resp[i] |=
                                                sdhci_readb(host,
                                                SDHCI_RESPONSE + (3-i)*4-1);
                        }
                } else {
                        host->cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE);
                }
        }

        host->cmd->error = 0;

        /* Finished CMD23, now send actual command. */
        if (host->cmd == host->mrq->sbc) {
                host->cmd = NULL;
                sdhci_send_command(host, host->mrq->cmd);
        } else {

                /* Processed actual command. */
                if (host->data && host->data_early)
                        sdhci_finish_data(host);

                if (!host->cmd->data)
                        tasklet_schedule(&host->finish_tasklet);

                host->cmd = NULL;
        }
}

static u16 sdhci_get_preset_value(struct sdhci_host *host)
{
        u16 ctrl, preset = 0;

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

        switch (ctrl & SDHCI_CTRL_UHS_MASK) {
        case SDHCI_CTRL_UHS_SDR12:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR12);
                break;
        case SDHCI_CTRL_UHS_SDR25:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR25);
                break;
        case SDHCI_CTRL_UHS_SDR50:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR50);
                break;
        case SDHCI_CTRL_UHS_SDR104:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR104);
                break;
        case SDHCI_CTRL_UHS_DDR50:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_DDR50);
                break;
        default:
                pr_warn("%s: Invalid UHS-I mode selected\n",
                        mmc_hostname(host->mmc));
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR12);
                break;
        }
        return preset;
}

static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
        int div = 0; /* Initialized for compiler warning */
        int real_div = div, clk_mul = 1;
        u16 clk = 0;
        unsigned long timeout;

        if (clock && clock == host->clock)
                return;

        host->mmc->actual_clock = 0;

        if (host->ops->set_clock) {
                host->ops->set_clock(host, clock);
                if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK)
                        return;
        }

        sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);

        if (clock == 0)
                goto out;

        if (host->version >= SDHCI_SPEC_300) {
                if (sdhci_readw(host, SDHCI_HOST_CONTROL2) &
                        SDHCI_CTRL_PRESET_VAL_ENABLE) {
                        u16 pre_val;

                        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                        pre_val = sdhci_get_preset_value(host);
                        div = (pre_val & SDHCI_PRESET_SDCLK_FREQ_MASK)
                                >> SDHCI_PRESET_SDCLK_FREQ_SHIFT;
                        if (host->clk_mul &&
                                (pre_val & SDHCI_PRESET_CLKGEN_SEL_MASK)) {
                                clk = SDHCI_PROG_CLOCK_MODE;
                                real_div = div + 1;
                                clk_mul = host->clk_mul;
                        } else {
                                real_div = max_t(int, 1, div << 1);
                        }
                        goto clock_set;
                }

                /*
                 * Check if the Host Controller supports Programmable Clock
                 * Mode.
                 */
                if (host->clk_mul) {
                        for (div = 1; div <= 1024; div++) {
                                if ((host->max_clk * host->clk_mul / div)
                                        <= clock)
                                        break;
                        }
                        /*
                         * Set Programmable Clock Mode in the Clock
                         * Control register.
                         */
                        clk = SDHCI_PROG_CLOCK_MODE;
                        real_div = div;
                        clk_mul = host->clk_mul;
                        div--;
                } else {
                        /* Version 3.00 divisors must be a multiple of 2. */
                        if (host->max_clk <= clock)
                                div = 1;
                        else {
                                for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
                                     div += 2) {
                                        if ((host->max_clk / div) <= clock)
                                                break;
                                }
                        }
                        real_div = div;
                        div >>= 1;
                }
        } else {
                /* Version 2.00 divisors must be a power of 2. */
                for (div = 1; div < SDHCI_MAX_DIV_SPEC_200; div *= 2) {
                        if ((host->max_clk / div) <= clock)
                                break;
                }
                real_div = div;
                div >>= 1;
        }

clock_set:
        if (real_div)
                host->mmc->actual_clock = (host->max_clk * clk_mul) / real_div;

        clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
        clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
                << SDHCI_DIVIDER_HI_SHIFT;
        clk |= SDHCI_CLOCK_INT_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

        /* Wait max 20 ms */
        timeout = 20;
        while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
                & SDHCI_CLOCK_INT_STABLE)) {
                if (timeout == 0) {
                        pr_err("%s: Internal clock never "
                                "stabilised.\n", mmc_hostname(host->mmc));
                        sdhci_dumpregs(host);
                        return;
                }
                timeout--;
                mdelay(1);
        }

        clk |= SDHCI_CLOCK_CARD_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

out:
        host->clock = clock;
}

static inline void sdhci_update_clock(struct sdhci_host *host)
{
        unsigned int clock;

        clock = host->clock;
        host->clock = 0;
        sdhci_set_clock(host, clock);
}

static int sdhci_set_power(struct sdhci_host *host, unsigned short power)
{
        u8 pwr = 0;

        if (power != (unsigned short)-1) {
                switch (1 << power) {
                case MMC_VDD_165_195:
                        pwr = SDHCI_POWER_180;
                        break;
                case MMC_VDD_29_30:
                case MMC_VDD_30_31:
                        pwr = SDHCI_POWER_300;
                        break;
                case MMC_VDD_32_33:
                case MMC_VDD_33_34:
                        pwr = SDHCI_POWER_330;
                        break;
                default:
                        BUG();
                }
        }

        if (host->pwr == pwr)
                return -1;

        host->pwr = pwr;

        if (pwr == 0) {
                sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
                if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
                        sdhci_runtime_pm_bus_off(host);
                return 0;
        }

        /*
         * Spec says that we should clear the power reg before setting
         * a new value. Some controllers don't seem to like this though.
         */
        if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE))
                sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);

        /*
         * At least the Marvell CaFe chip gets confused if we set the voltage
         * and set turn on power at the same time, so set the voltage first.
         */
        if (host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER)
                sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);

        pwr |= SDHCI_POWER_ON;

        sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);

        if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
                sdhci_runtime_pm_bus_on(host);

        /*
         * Some controllers need an extra 10ms delay of 10ms before they
         * can apply clock after applying power
         */
        if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
                mdelay(10);

        return power;
}

/*****************************************************************************\
 *                                                                           *
 * MMC callbacks                                                             *
 *                                                                           *
\*****************************************************************************/

static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sdhci_host *host;
        int present;
        unsigned long flags;
        u32 tuning_opcode;

        host = mmc_priv(mmc);

        sdhci_runtime_pm_get(host);

        spin_lock_irqsave(&host->lock, flags);

        WARN_ON(host->mrq != NULL);

#ifndef SDHCI_USE_LEDS_CLASS
        sdhci_activate_led(host);
#endif

        /*
         * Ensure we don't send the STOP for non-SET_BLOCK_COUNTED
         * requests if Auto-CMD12 is enabled.
         */
        if (!mrq->sbc && (host->flags & SDHCI_AUTO_CMD12)) {
                if (mrq->stop) {
                        mrq->data->stop = NULL;
                        mrq->stop = NULL;
                }
        }

        host->mrq = mrq;

        /*
         * Firstly check card presence from cd-gpio.  The return could
         * be one of the following possibilities:
         *     negative: cd-gpio is not available
         *     zero: cd-gpio is used, and card is removed
         *     one: cd-gpio is used, and card is present
         */
        present = mmc_gpio_get_cd(host->mmc);
        if (present < 0) {
                /* If polling, assume that the card is always present. */
                if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
                        present = 1;
                else
                        present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
                                        SDHCI_CARD_PRESENT;
        }

        if (!present || host->flags & SDHCI_DEVICE_DEAD) {
                host->mrq->cmd->error = -ENOMEDIUM;
                tasklet_schedule(&host->finish_tasklet);
        } else {
                u32 present_state;

                present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
                /*
                 * Check if the re-tuning timer has already expired and there
                 * is no on-going data transfer. If so, we need to execute
                 * tuning procedure before sending command.
                 */
                if ((host->flags & SDHCI_NEEDS_RETUNING) &&
                    !(present_state & (SDHCI_DOING_WRITE | SDHCI_DOING_READ))) {
                        if (mmc->card) {
                                /* eMMC uses cmd21 but sd and sdio use cmd19 */
                                tuning_opcode =
                                        mmc->card->type == MMC_TYPE_MMC ?
                                        MMC_SEND_TUNING_BLOCK_HS200 :
                                        MMC_SEND_TUNING_BLOCK;

                                /* Here we need to set the host->mrq to NULL,
                                 * in case the pending finish_tasklet
                                 * finishes it incorrectly.
                                 */
                                host->mrq = NULL;

                                spin_unlock_irqrestore(&host->lock, flags);
                                sdhci_execute_tuning(mmc, tuning_opcode);
                                spin_lock_irqsave(&host->lock, flags);

                                /* Restore original mmc_request structure */
                                host->mrq = mrq;
                        }
                }

                if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))
                        sdhci_send_command(host, mrq->sbc);
                else
                        sdhci_send_command(host, mrq->cmd);
        }

        mmiowb();
        spin_unlock_irqrestore(&host->lock, flags);
}

static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios)
{
        unsigned long flags;
        int vdd_bit = -1;
        u8 ctrl;

        spin_lock_irqsave(&host->lock, flags);

        if (host->flags & SDHCI_DEVICE_DEAD) {
                spin_unlock_irqrestore(&host->lock, flags);
                if (host->vmmc && ios->power_mode == MMC_POWER_OFF)
                        mmc_regulator_set_ocr(host->mmc, host->vmmc, 0);
                return;
        }

        /*
         * Reset the chip on each power off.
         * Should clear out any weird states.
         */
        if (ios->power_mode == MMC_POWER_OFF) {
                sdhci_writel(host, 0, SDHCI_SIGNAL_ENABLE);
                sdhci_reinit(host);
        }

        if (host->version >= SDHCI_SPEC_300 &&
                (ios->power_mode == MMC_POWER_UP) &&
                !(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN))
                sdhci_enable_preset_value(host, false);

        sdhci_set_clock(host, ios->clock);

        if (ios->power_mode == MMC_POWER_OFF)
                vdd_bit = sdhci_set_power(host, -1);
        else
                vdd_bit = sdhci_set_power(host, ios->vdd);

        if (host->vmmc && vdd_bit != -1) {
                spin_unlock_irqrestore(&host->lock, flags);
                mmc_regulator_set_ocr(host->mmc, host->vmmc, vdd_bit);
                spin_lock_irqsave(&host->lock, flags);
        }

        if (host->ops->platform_send_init_74_clocks)
                host->ops->platform_send_init_74_clocks(host, ios->power_mode);

        /*
         * If your platform has 8-bit width support but is not a v3 controller,
         * or if it requires special setup code, you should implement that in
         * platform_bus_width().
         */
        if (host->ops->platform_bus_width) {
                host->ops->platform_bus_width(host, ios->bus_width);
        } else {
                ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
                if (ios->bus_width == MMC_BUS_WIDTH_8) {
                        ctrl &= ~SDHCI_CTRL_4BITBUS;
                        if (host->version >= SDHCI_SPEC_300)
                                ctrl |= SDHCI_CTRL_8BITBUS;
                } else {
                        if (host->version >= SDHCI_SPEC_300)
                                ctrl &= ~SDHCI_CTRL_8BITBUS;
                        if (ios->bus_width == MMC_BUS_WIDTH_4)
                                ctrl |= SDHCI_CTRL_4BITBUS;
                        else
                                ctrl &= ~SDHCI_CTRL_4BITBUS;
                }
                sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
        }

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);

        if ((ios->timing == MMC_TIMING_SD_HS ||
             ios->timing == MMC_TIMING_MMC_HS)
            && !(host->quirks & SDHCI_QUIRK_NO_HISPD_BIT))
                ctrl |= SDHCI_CTRL_HISPD;
        else
                ctrl &= ~SDHCI_CTRL_HISPD;

        if (host->version >= SDHCI_SPEC_300) {
                u16 clk, ctrl_2;

                /* In case of UHS-I modes, set High Speed Enable */
                if ((ios->timing == MMC_TIMING_MMC_HS200) ||
                    (ios->timing == MMC_TIMING_UHS_SDR50) ||
                    (ios->timing == MMC_TIMING_UHS_SDR104) ||
                    (ios->timing == MMC_TIMING_UHS_DDR50) ||
                    (ios->timing == MMC_TIMING_UHS_SDR25))
                        ctrl |= SDHCI_CTRL_HISPD;

                ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                if (!(ctrl_2 & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
                        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
                        /*
                         * We only need to set Driver Strength if the
                         * preset value enable is not set.
                         */
                        ctrl_2 &= ~SDHCI_CTRL_DRV_TYPE_MASK;
                        if (ios->drv_type == MMC_SET_DRIVER_TYPE_A)
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_A;
                        else if (ios->drv_type == MMC_SET_DRIVER_TYPE_C)
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_C;

                        sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
                } else {
                        /*
                         * According to SDHC Spec v3.00, if the Preset Value
                         * Enable in the Host Control 2 register is set, we
                         * need to reset SD Clock Enable before changing High
                         * Speed Enable to avoid generating clock gliches.
                         */

                        /* Reset SD Clock Enable */
                        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                        clk &= ~SDHCI_CLOCK_CARD_EN;
                        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

                        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);

                        /* Re-enable SD Clock */
                        sdhci_update_clock(host);
                }


                /* Reset SD Clock Enable */
                clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                clk &= ~SDHCI_CLOCK_CARD_EN;
                sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

                if (host->ops->set_uhs_signaling)
                        host->ops->set_uhs_signaling(host, ios->timing);
                else {
                        ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                        /* Select Bus Speed Mode for host */
                        ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
                        if ((ios->timing == MMC_TIMING_MMC_HS200) ||
                            (ios->timing == MMC_TIMING_UHS_SDR104))
                                ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
                        else if (ios->timing == MMC_TIMING_UHS_SDR12)
                                ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
                        else if (ios->timing == MMC_TIMING_UHS_SDR25)
                                ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
                        else if (ios->timing == MMC_TIMING_UHS_SDR50)
                                ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
                        else if (ios->timing == MMC_TIMING_UHS_DDR50)
                                ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
                        sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
                }

                if (!(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN) &&
                                ((ios->timing == MMC_TIMING_UHS_SDR12) ||
                                 (ios->timing == MMC_TIMING_UHS_SDR25) ||
                                 (ios->timing == MMC_TIMING_UHS_SDR50) ||
                                 (ios->timing == MMC_TIMING_UHS_SDR104) ||
                                 (ios->timing == MMC_TIMING_UHS_DDR50))) {
                        u16 preset;

                        sdhci_enable_preset_value(host, true);
                        preset = sdhci_get_preset_value(host);
                        ios->drv_type = (preset & SDHCI_PRESET_DRV_MASK)
                                >> SDHCI_PRESET_DRV_SHIFT;
                }

                /* Re-enable SD Clock */
                sdhci_update_clock(host);
        } else
                sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);

        /*
         * Some (ENE) controllers go apeshit on some ios operation,
         * signalling timeout and CRC errors even on CMD0. Resetting
         * it on each ios seems to solve the problem.
         */
        if(host->quirks & SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS)
                sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);

        mmiowb();
        spin_unlock_irqrestore(&host->lock, flags);
}

static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);

        sdhci_runtime_pm_get(host);
        sdhci_do_set_ios(host, ios);
        sdhci_runtime_pm_put(host);
}

static int sdhci_do_get_cd(struct sdhci_host *host)
{
        int gpio_cd = mmc_gpio_get_cd(host->mmc);

        if (host->flags & SDHCI_DEVICE_DEAD)
                return 0;

        /* If polling/nonremovable, assume that the card is always present. */
        if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
            (host->mmc->caps & MMC_CAP_NONREMOVABLE))
                return 1;

        /* Try slot gpio detect */
        if (!IS_ERR_VALUE(gpio_cd))
                return !!gpio_cd;

        /* Host native card detect */
        return !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
}

static int sdhci_get_cd(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);
        int ret;

        sdhci_runtime_pm_get(host);
        ret = sdhci_do_get_cd(host);
        sdhci_runtime_pm_put(host);
        return ret;
}

static int sdhci_check_ro(struct sdhci_host *host)
{
        unsigned long flags;
        int is_readonly;

        spin_lock_irqsave(&host->lock, flags);

        if (host->flags & SDHCI_DEVICE_DEAD)
                is_readonly = 0;
        else if (host->ops->get_ro)
                is_readonly = host->ops->get_ro(host);
        else
                is_readonly = !(sdhci_readl(host, SDHCI_PRESENT_STATE)
                                & SDHCI_WRITE_PROTECT);

        spin_unlock_irqrestore(&host->lock, flags);

        /* This quirk needs to be replaced by a callback-function later */
        return host->quirks & SDHCI_QUIRK_INVERTED_WRITE_PROTECT ?
                !is_readonly : is_readonly;
}

#define SAMPLE_COUNT    5

static int sdhci_do_get_ro(struct sdhci_host *host)
{
        int i, ro_count;

        if (!(host->quirks & SDHCI_QUIRK_UNSTABLE_RO_DETECT))
                return sdhci_check_ro(host);

        ro_count = 0;
        for (i = 0; i < SAMPLE_COUNT; i++) {
                if (sdhci_check_ro(host)) {
                        if (++ro_count > SAMPLE_COUNT / 2)
                                return 1;
                }
                msleep(30);
        }
        return 0;
}

static void sdhci_hw_reset(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);

        if (host->ops && host->ops->hw_reset)
                host->ops->hw_reset(host);
}

static int sdhci_get_ro(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);
        int ret;

        sdhci_runtime_pm_get(host);
        ret = sdhci_do_get_ro(host);
        sdhci_runtime_pm_put(host);
        return ret;
}

static void sdhci_enable_sdio_irq_nolock(struct sdhci_host *host, int enable)
{
        if (host->flags & SDHCI_DEVICE_DEAD)
                goto out;

        if (enable)
                host->flags |= SDHCI_SDIO_IRQ_ENABLED;
        else
                host->flags &= ~SDHCI_SDIO_IRQ_ENABLED;

        /* SDIO IRQ will be enabled as appropriate in runtime resume */
        if (host->runtime_suspended)
                goto out;

        if (enable)
                sdhci_unmask_irqs(host, SDHCI_INT_CARD_INT);
        else
                sdhci_mask_irqs(host, SDHCI_INT_CARD_INT);
out:
        mmiowb();
}

static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
{
        struct sdhci_host *host = mmc_priv(mmc);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);
        sdhci_enable_sdio_irq_nolock(host, enable);
        spin_unlock_irqrestore(&host->lock, flags);
}

static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,
                                                struct mmc_ios *ios)
{
        u16 ctrl;
        int ret;

        /*
         * Signal Voltage Switching is only applicable for Host Controllers
         * v3.00 and above.
         */
        if (host->version < SDHCI_SPEC_300)
                return 0;

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

        switch (ios->signal_voltage) {
        case MMC_SIGNAL_VOLTAGE_330:
                /* Set 1.8V Signal Enable in the Host Control2 register to 0 */
                ctrl &= ~SDHCI_CTRL_VDD_180;
                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);

                if (host->vqmmc) {
                        ret = regulator_set_voltage(host->vqmmc, 2700000, 3600000);
                        if (ret) {
                                pr_warning("%s: Switching to 3.3V signalling voltage "
                                                " failed\n", mmc_hostname(host->mmc));
                                return -EIO;
                        }
                }
                /* Wait for 5ms */
                usleep_range(5000, 5500);

                /* 3.3V regulator output should be stable within 5 ms */
                ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                if (!(ctrl & SDHCI_CTRL_VDD_180))
                        return 0;

                pr_warning("%s: 3.3V regulator output did not became stable\n",
                                mmc_hostname(host->mmc));

                return -EAGAIN;
        case MMC_SIGNAL_VOLTAGE_180:
                if (host->vqmmc) {
                        ret = regulator_set_voltage(host->vqmmc,
                                        1700000, 1950000);
                        if (ret) {
                                pr_warning("%s: Switching to 1.8V signalling voltage "
                                                " failed\n", mmc_hostname(host->mmc));
                                return -EIO;
                        }
                }

                /*
                 * Enable 1.8V Signal Enable in the Host Control2
                 * register
                 */
                ctrl |= SDHCI_CTRL_VDD_180;
                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);

                /* Wait for 5ms */
                usleep_range(5000, 5500);

                /* 1.8V regulator output should be stable within 5 ms */
                ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                if (ctrl & SDHCI_CTRL_VDD_180)
                        return 0;

                pr_warning("%s: 1.8V regulator output did not became stable\n",
                                mmc_hostname(host->mmc));

                return -EAGAIN;
        case MMC_SIGNAL_VOLTAGE_120:
                if (host->vqmmc) {
                        ret = regulator_set_voltage(host->vqmmc, 1100000, 1300000);
                        if (ret) {
                                pr_warning("%s: Switching to 1.2V signalling voltage "
                                                " failed\n", mmc_hostname(host->mmc));
                                return -EIO;
                        }
                }
                return 0;
        default:
                /* No signal voltage switch required */
                return 0;
        }
}

static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
        struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);
        int err;

        if (host->version < SDHCI_SPEC_300)
                return 0;
        sdhci_runtime_pm_get(host);
        err = sdhci_do_start_signal_voltage_switch(host, ios);
        sdhci_runtime_pm_put(host);
        return err;
}

static int sdhci_card_busy(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);
        u32 present_state;

        sdhci_runtime_pm_get(host);
        /* Check whether DAT[3:0] is 0000 */
        present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
        sdhci_runtime_pm_put(host);

        return !(present_state & SDHCI_DATA_LVL_MASK);
}

static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
        struct sdhci_host *host;
        u16 ctrl;
        u32 ier;
        int tuning_loop_counter = MAX_TUNING_LOOP;
        unsigned long timeout;
        int err = 0;
        bool requires_tuning_nonuhs = false;

        host = mmc_priv(mmc);

        sdhci_runtime_pm_get(host);
        disable_irq(host->irq);
        spin_lock(&host->lock);

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

        /*
         * The Host Controller needs tuning only in case of SDR104 mode
         * and for SDR50 mode when Use Tuning for SDR50 is set in the
         * Capabilities register.
         * If the Host Controller supports the HS200 mode then the
         * tuning function has to be executed.
         */
        if (((ctrl & SDHCI_CTRL_UHS_MASK) == SDHCI_CTRL_UHS_SDR50) &&
            (host->flags & SDHCI_SDR50_NEEDS_TUNING ||
             host->flags & SDHCI_SDR104_NEEDS_TUNING))
                requires_tuning_nonuhs = true;

        if (((ctrl & SDHCI_CTRL_UHS_MASK) == SDHCI_CTRL_UHS_SDR104) ||
            requires_tuning_nonuhs)
                ctrl |= SDHCI_CTRL_EXEC_TUNING;
        else {
                spin_unlock(&host->lock);
                enable_irq(host->irq);
                sdhci_runtime_pm_put(host);
                return 0;
        }

        if (host->ops->platform_execute_tuning) {
                spin_unlock(&host->lock);
                enable_irq(host->irq);
                err = host->ops->platform_execute_tuning(host, opcode);
                sdhci_runtime_pm_put(host);
                return err;
        }

        sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);

        /*
         * As per the Host Controller spec v3.00, tuning command
         * generates Buffer Read Ready interrupt, so enable that.
         *
         * Note: The spec clearly says that when tuning sequence
         * is being performed, the controller does not generate
         * interrupts other than Buffer Read Ready interrupt. But
         * to make sure we don't hit a controller bug, we _only_
         * enable Buffer Read Ready interrupt here.
         */
        ier = sdhci_readl(host, SDHCI_INT_ENABLE);
        sdhci_clear_set_irqs(host, ier, SDHCI_INT_DATA_AVAIL);

        /*
         * Issue CMD19 repeatedly till Execute Tuning is set to 0 or the number
         * of loops reaches 40 times or a timeout of 150ms occurs.
         */
        timeout = 150;
        do {
                struct mmc_command cmd = {0};
                struct mmc_request mrq = {NULL};

                if (!tuning_loop_counter && !timeout)
                        break;

                cmd.opcode = opcode;
                cmd.arg = 0;
                cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
                cmd.retries = 0;
                cmd.data = NULL;
                cmd.error = 0;

                mrq.cmd = &cmd;
                host->mrq = &mrq;

                /*
                 * In response to CMD19, the card sends 64 bytes of tuning
                 * block to the Host Controller. So we set the block size
                 * to 64 here.
                 */
                if (cmd.opcode == MMC_SEND_TUNING_BLOCK_HS200) {
                        if (mmc->ios.bus_width == MMC_BUS_WIDTH_8)
                                sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 128),
                                             SDHCI_BLOCK_SIZE);
                        else if (mmc->ios.bus_width == MMC_BUS_WIDTH_4)
                                sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
                                             SDHCI_BLOCK_SIZE);
                } else {
                        sdhci_writew(host, SDHCI_MAKE_BLKSZ(7, 64),
                                     SDHCI_BLOCK_SIZE);
                }

                /*
                 * The tuning block is sent by the card to the host controller.
                 * So we set the TRNS_READ bit in the Transfer Mode register.
                 * This also takes care of setting DMA Enable and Multi Block
                 * Select in the same register to 0.
                 */
                sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);

                sdhci_send_command(host, &cmd);

                host->cmd = NULL;
                host->mrq = NULL;

                spin_unlock(&host->lock);
                enable_irq(host->irq);

                /* Wait for Buffer Read Ready interrupt */
                wait_event_interruptible_timeout(host->buf_ready_int,
                                        (host->tuning_done == 1),
                                        msecs_to_jiffies(50));
                disable_irq(host->irq);
                spin_lock(&host->lock);

                if (!host->tuning_done) {
                        pr_info(DRIVER_NAME ": Timeout waiting for "
                                "Buffer Read Ready interrupt during tuning "
                                "procedure, falling back to fixed sampling "
                                "clock\n");
                        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                        ctrl &= ~SDHCI_CTRL_TUNED_CLK;
                        ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
                        sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);

                        err = -EIO;
                        goto out;
                }

                host->tuning_done = 0;

                ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                tuning_loop_counter--;
                timeout--;
                mdelay(1);
        } while (ctrl & SDHCI_CTRL_EXEC_TUNING);

        /*
         * The Host Driver has exhausted the maximum number of loops allowed,
         * so use fixed sampling frequency.
         */
        if (!tuning_loop_counter || !timeout) {
                ctrl &= ~SDHCI_CTRL_TUNED_CLK;
                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
                err = -EIO;
        } else {
                if (!(ctrl & SDHCI_CTRL_TUNED_CLK)) {
                        pr_info(DRIVER_NAME ": Tuning procedure"
                                " failed, falling back to fixed sampling"
                                " clock\n");
                        err = -EIO;
                }
        }

out:
        /*
         * If this is the very first time we are here, we start the retuning
         * timer. Since only during the first time, SDHCI_NEEDS_RETUNING
         * flag won't be set, we check this condition before actually starting
         * the timer.
         */
        if (!(host->flags & SDHCI_NEEDS_RETUNING) && host->tuning_count &&
            (host->tuning_mode == SDHCI_TUNING_MODE_1)) {
                host->flags |= SDHCI_USING_RETUNING_TIMER;
                mod_timer(&host->tuning_timer, jiffies +
                        host->tuning_count * HZ);
                /* Tuning mode 1 limits the maximum data length to 4MB */
                mmc->max_blk_count = (4 * 1024 * 1024) / mmc->max_blk_size;
        } else {
                host->flags &= ~SDHCI_NEEDS_RETUNING;
                /* Reload the new initial value for timer */
                if (host->tuning_mode == SDHCI_TUNING_MODE_1)
                        mod_timer(&host->tuning_timer, jiffies +
                                host->tuning_count * HZ);
        }

        /*
         * In case tuning fails, host controllers which support re-tuning can
         * try tuning again at a later time, when the re-tuning timer expires.
         * So for these controllers, we return 0. Since there might be other
         * controllers who do not have this capability, we return error for
         * them. SDHCI_USING_RETUNING_TIMER means the host is currently using
         * a retuning timer to do the retuning for the card.
         */
        if (err && (host->flags & SDHCI_USING_RETUNING_TIMER))
                err = 0;

        sdhci_clear_set_irqs(host, SDHCI_INT_DATA_AVAIL, ier);
        spin_unlock(&host->lock);
        enable_irq(host->irq);
        sdhci_runtime_pm_put(host);

        return err;
}


static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
{
        u16 ctrl;

        /* Host Controller v3.00 defines preset value registers */
        if (host->version < SDHCI_SPEC_300)
                return;

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

        /*
         * We only enable or disable Preset Value if they are not already
         * enabled or disabled respectively. Otherwise, we bail out.
         */
        if (enable && !(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
                ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE;
                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
                host->flags |= SDHCI_PV_ENABLED;
        } else if (!enable && (ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
                ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;
                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
                host->flags &= ~SDHCI_PV_ENABLED;
        }
}

static void sdhci_card_event(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);
        unsigned long flags;

        /* First check if client has provided their own card event */
        if (host->ops->card_event)
                host->ops->card_event(host);

        spin_lock_irqsave(&host->lock, flags);

        /* Check host->mrq first in case we are runtime suspended */
        if (host->mrq && !sdhci_do_get_cd(host)) {
                pr_err("%s: Card removed during transfer!\n",
                        mmc_hostname(host->mmc));
                pr_err("%s: Resetting controller.\n",
                        mmc_hostname(host->mmc));

                sdhci_reset(host, SDHCI_RESET_CMD);
                sdhci_reset(host, SDHCI_RESET_DATA);

                host->mrq->cmd->error = -ENOMEDIUM;
                tasklet_schedule(&host->finish_tasklet);
        }

        spin_unlock_irqrestore(&host->lock, flags);
}

static const struct mmc_host_ops sdhci_ops = {
        .request        = sdhci_request,
        .set_ios        = sdhci_set_ios,
        .get_cd         = sdhci_get_cd,
        .get_ro         = sdhci_get_ro,
        .hw_reset       = sdhci_hw_reset,
        .enable_sdio_irq = sdhci_enable_sdio_irq,
        .start_signal_voltage_switch    = sdhci_start_signal_voltage_switch,
        .execute_tuning                 = sdhci_execute_tuning,
        .card_event                     = sdhci_card_event,
        .card_busy      = sdhci_card_busy,
};

/*****************************************************************************\
 *                                                                           *
 * Tasklets                                                                  *
 *                                                                           *
\*****************************************************************************/

static void sdhci_tasklet_card(unsigned long param)
{
        struct sdhci_host *host = (struct sdhci_host*)param;

        sdhci_card_event(host->mmc);

        mmc_detect_change(host->mmc, msecs_to_jiffies(200));
}

static void sdhci_tasklet_finish(unsigned long param)
{
        struct sdhci_host *host;
        unsigned long flags;
        struct mmc_request *mrq;

        host = (struct sdhci_host*)param;

        spin_lock_irqsave(&host->lock, flags);

        /*
         * If this tasklet gets rescheduled while running, it will
         * be run again afterwards but without any active request.
         */
        if (!host->mrq) {
                spin_unlock_irqrestore(&host->lock, flags);
                return;
        }

        del_timer(&host->timer);

        mrq = host->mrq;

        /*
         * The controller needs a reset of internal state machines
         * upon error conditions.
         */
        if (!(host->flags & SDHCI_DEVICE_DEAD) &&
            ((mrq->cmd && mrq->cmd->error) ||
                 (mrq->data && (mrq->data->error ||
                  (mrq->data->stop && mrq->data->stop->error))) ||
                   (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST))) {

                /* Some controllers need this kick or reset won't work here */
                if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
                        /* This is to force an update */
                        sdhci_update_clock(host);

                /* Spec says we should do both at the same time, but Ricoh
                   controllers do not like that. */
                sdhci_reset(host, SDHCI_RESET_CMD);
                sdhci_reset(host, SDHCI_RESET_DATA);
        }

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

#ifndef SDHCI_USE_LEDS_CLASS
        sdhci_deactivate_led(host);
#endif

        mmiowb();
        spin_unlock_irqrestore(&host->lock, flags);

        mmc_request_done(host->mmc, mrq);
        sdhci_runtime_pm_put(host);
}

static void sdhci_timeout_timer(unsigned long data)
{
        struct sdhci_host *host;
        unsigned long flags;

        host = (struct sdhci_host*)data;

        spin_lock_irqsave(&host->lock, flags);

        if (host->mrq) {
                pr_err("%s: Timeout waiting for hardware "
                        "interrupt.\n", mmc_hostname(host->mmc));
                sdhci_dumpregs(host);

                if (host->data) {
                        host->data->error = -ETIMEDOUT;
                        sdhci_finish_data(host);
                } else {
                        if (host->cmd)
                                host->cmd->error = -ETIMEDOUT;
                        else
                                host->mrq->cmd->error = -ETIMEDOUT;

                        tasklet_schedule(&host->finish_tasklet);
                }
        }

        mmiowb();
        spin_unlock_irqrestore(&host->lock, flags);
}

static void sdhci_tuning_timer(unsigned long data)
{
        struct sdhci_host *host;
        unsigned long flags;

        host = (struct sdhci_host *)data;

        spin_lock_irqsave(&host->lock, flags);

        host->flags |= SDHCI_NEEDS_RETUNING;

        spin_unlock_irqrestore(&host->lock, flags);
}

/*****************************************************************************\
 *                                                                           *
 * Interrupt handling                                                        *
 *                                                                           *
\*****************************************************************************/

static void sdhci_cmd_irq(struct sdhci_host *host, u32 intmask)
{
        BUG_ON(intmask == 0);

        if (!host->cmd) {
                pr_err("%s: Got command interrupt 0x%08x even "
                        "though no command operation was in progress.\n",
                        mmc_hostname(host->mmc), (unsigned)intmask);
                sdhci_dumpregs(host);
                return;
        }

        if (intmask & SDHCI_INT_TIMEOUT)
                host->cmd->error = -ETIMEDOUT;
        else if (intmask & (SDHCI_INT_CRC | SDHCI_INT_END_BIT |
                        SDHCI_INT_INDEX))
                host->cmd->error = -EILSEQ;

        if (host->cmd->error) {
                tasklet_schedule(&host->finish_tasklet);
                return;
        }

        /*
         * The host can send and interrupt when the busy state has
         * ended, allowing us to wait without wasting CPU cycles.
         * Unfortunately this is overloaded on the "data complete"
         * interrupt, so we need to take some care when handling
         * it.
         *
         * Note: The 1.0 specification is a bit ambiguous about this
         *       feature so there might be some problems with older
         *       controllers.
         */
        if (host->cmd->flags & MMC_RSP_BUSY) {
                if (host->cmd->data)
                        DBG("Cannot wait for busy signal when also "
                                "doing a data transfer");
                else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ))
                        return;

                /* The controller does not support the end-of-busy IRQ,
                 * fall through and take the SDHCI_INT_RESPONSE */
        }

        if (intmask & SDHCI_INT_RESPONSE)
                sdhci_finish_command(host);
}

#ifdef CONFIG_MMC_DEBUG
static void sdhci_show_adma_error(struct sdhci_host *host)
{
        const char *name = mmc_hostname(host->mmc);
        u8 *desc = host->adma_desc;
        __le32 *dma;
        __le16 *len;
        u8 attr;

        sdhci_dumpregs(host);

        while (true) {
                dma = (__le32 *)(desc + 4);
                len = (__le16 *)(desc + 2);
                attr = *desc;

                DBG("%s: %p: DMA 0x%08x, LEN 0x%04x, Attr=0x%02x\n",
                    name, desc, le32_to_cpu(*dma), le16_to_cpu(*len), attr);

                desc += 8;

                if (attr & 2)
                        break;
        }
}
#else
static void sdhci_show_adma_error(struct sdhci_host *host) { }
#endif

static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
{
        u32 command;
        BUG_ON(intmask == 0);

        /* CMD19 generates _only_ Buffer Read Ready interrupt */
        if (intmask & SDHCI_INT_DATA_AVAIL) {
                command = SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND));
                if (command == MMC_SEND_TUNING_BLOCK ||
                    command == MMC_SEND_TUNING_BLOCK_HS200) {
                        host->tuning_done = 1;
                        wake_up(&host->buf_ready_int);
                        return;
                }
        }

        if (!host->data) {
                /*
                 * The "data complete" interrupt is also used to
                 * indicate that a busy state has ended. See comment
                 * above in sdhci_cmd_irq().
                 */
                if (host->cmd && (host->cmd->flags & MMC_RSP_BUSY)) {
                        if (intmask & SDHCI_INT_DATA_END) {
                                sdhci_finish_command(host);
                                return;
                        }
                }

                pr_err("%s: Got data interrupt 0x%08x even "
                        "though no data operation was in progress.\n",
                        mmc_hostname(host->mmc), (unsigned)intmask);
                sdhci_dumpregs(host);

                return;
        }

        if (intmask & SDHCI_INT_DATA_TIMEOUT)
                host->data->error = -ETIMEDOUT;
        else if (intmask & SDHCI_INT_DATA_END_BIT)
                host->data->error = -EILSEQ;
        else if ((intmask & SDHCI_INT_DATA_CRC) &&
                SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
                        != MMC_BUS_TEST_R)
                host->data->error = -EILSEQ;
        else if (intmask & SDHCI_INT_ADMA_ERROR) {
                pr_err("%s: ADMA error\n", mmc_hostname(host->mmc));
                sdhci_show_adma_error(host);
                host->data->error = -EIO;
                if (host->ops->adma_workaround)
                        host->ops->adma_workaround(host, intmask);
        }

        if (host->data->error)
                sdhci_finish_data(host);
        else {
                if (intmask & (SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL))
                        sdhci_transfer_pio(host);

                /*
                 * We currently don't do anything fancy with DMA
                 * boundaries, but as we can't disable the feature
                 * we need to at least restart the transfer.
                 *
                 * According to the spec sdhci_readl(host, SDHCI_DMA_ADDRESS)
                 * should return a valid address to continue from, but as
                 * some controllers are faulty, don't trust them.
                 */
                if (intmask & SDHCI_INT_DMA_END) {
                        u32 dmastart, dmanow;
                        dmastart = sg_dma_address(host->data->sg);
                        dmanow = dmastart + host->data->bytes_xfered;
                        /*
                         * Force update to the next DMA block boundary.
                         */
                        dmanow = (dmanow &
                                ~(SDHCI_DEFAULT_BOUNDARY_SIZE - 1)) +
                                SDHCI_DEFAULT_BOUNDARY_SIZE;
                        host->data->bytes_xfered = dmanow - dmastart;
                        DBG("%s: DMA base 0x%08x, transferred 0x%06x bytes,"
                                " next 0x%08x\n",
                                mmc_hostname(host->mmc), dmastart,
                                host->data->bytes_xfered, dmanow);
                        sdhci_writel(host, dmanow, SDHCI_DMA_ADDRESS);
                }

                if (intmask & SDHCI_INT_DATA_END) {
                        if (host->cmd) {
                                /*
                                 * Data managed to finish before the
                                 * command completed. Make sure we do
                                 * things in the proper order.
                                 */
                                host->data_early = 1;
                        } else {
                                sdhci_finish_data(host);
                        }
                }
        }
}

static irqreturn_t sdhci_irq(int irq, void *dev_id)
{
        irqreturn_t result;
        struct sdhci_host *host = dev_id;
        u32 intmask, unexpected = 0;
        int cardint = 0, max_loops = 16;

        spin_lock(&host->lock);

        if (host->runtime_suspended) {
                spin_unlock(&host->lock);
                pr_warning("%s: got irq while runtime suspended\n",
                       mmc_hostname(host->mmc));
                return IRQ_HANDLED;
        }

        intmask = sdhci_readl(host, SDHCI_INT_STATUS);

        if (!intmask || intmask == 0xffffffff) {
                result = IRQ_NONE;
                goto out;
        }

again:
        DBG("*** %s got interrupt: 0x%08x\n",
                mmc_hostname(host->mmc), intmask);

        if (intmask & (SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE)) {
                u32 present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
                              SDHCI_CARD_PRESENT;

                /*
                 * There is a observation on i.mx esdhc.  INSERT bit will be
                 * immediately set again when it gets cleared, if a card is
                 * inserted.  We have to mask the irq to prevent interrupt
                 * storm which will freeze the system.  And the REMOVE gets
                 * the same situation.
                 *
                 * More testing are needed here to ensure it works for other
                 * platforms though.
                 */
                sdhci_mask_irqs(host, present ? SDHCI_INT_CARD_INSERT :
                                                SDHCI_INT_CARD_REMOVE);
                sdhci_unmask_irqs(host, present ? SDHCI_INT_CARD_REMOVE :
                                                  SDHCI_INT_CARD_INSERT);

                sdhci_writel(host, intmask & (SDHCI_INT_CARD_INSERT |
                             SDHCI_INT_CARD_REMOVE), SDHCI_INT_STATUS);
                intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE);
                tasklet_schedule(&host->card_tasklet);
        }

        if (intmask & SDHCI_INT_CMD_MASK) {
                sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK,
                        SDHCI_INT_STATUS);
                sdhci_cmd_irq(host, intmask & SDHCI_INT_CMD_MASK);
        }

        if (intmask & SDHCI_INT_DATA_MASK) {
                sdhci_writel(host, intmask & SDHCI_INT_DATA_MASK,
                        SDHCI_INT_STATUS);
                sdhci_data_irq(host, intmask & SDHCI_INT_DATA_MASK);
        }

        intmask &= ~(SDHCI_INT_CMD_MASK | SDHCI_INT_DATA_MASK);

        intmask &= ~SDHCI_INT_ERROR;

        if (intmask & SDHCI_INT_BUS_POWER) {
                pr_err("%s: Card is consuming too much power!\n",
                        mmc_hostname(host->mmc));
                sdhci_writel(host, SDHCI_INT_BUS_POWER, SDHCI_INT_STATUS);
        }

        intmask &= ~SDHCI_INT_BUS_POWER;

        if (intmask & SDHCI_INT_CARD_INT)
                cardint = 1;

        intmask &= ~SDHCI_INT_CARD_INT;

        if (intmask) {
                unexpected |= intmask;
                sdhci_writel(host, intmask, SDHCI_INT_STATUS);
        }

        result = IRQ_HANDLED;

        intmask = sdhci_readl(host, SDHCI_INT_STATUS);

        /*
         * If we know we'll call the driver to signal SDIO IRQ, disregard
         * further indications of Card Interrupt in the status to avoid a
         * needless loop.
         */
        if (cardint)
                intmask &= ~SDHCI_INT_CARD_INT;
        if (intmask && --max_loops)
                goto again;
out:
        spin_unlock(&host->lock);

        if (unexpected) {
                pr_err("%s: Unexpected interrupt 0x%08x.\n",
                           mmc_hostname(host->mmc), unexpected);
                sdhci_dumpregs(host);
        }
        /*
         * We have to delay this as it calls back into the driver.
         */
        if (cardint)
                mmc_signal_sdio_irq(host->mmc);

        return result;
}

/*****************************************************************************\
 *                                                                           *
 * Suspend/resume                                                            *
 *                                                                           *
\*****************************************************************************/

#ifdef CONFIG_PM
void sdhci_enable_irq_wakeups(struct sdhci_host *host)
{
        u8 val;
        u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
                        | SDHCI_WAKE_ON_INT;

        val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
        val |= mask ;
        /* Avoid fake wake up */
        if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
                val &= ~(SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE);
        sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
}
EXPORT_SYMBOL_GPL(sdhci_enable_irq_wakeups);

void sdhci_disable_irq_wakeups(struct sdhci_host *host)
{
        u8 val;
        u8 mask = SDHCI_WAKE_ON_INSERT | SDHCI_WAKE_ON_REMOVE
                        | SDHCI_WAKE_ON_INT;

        val = sdhci_readb(host, SDHCI_WAKE_UP_CONTROL);
        val &= ~mask;
        sdhci_writeb(host, val, SDHCI_WAKE_UP_CONTROL);
}
EXPORT_SYMBOL_GPL(sdhci_disable_irq_wakeups);

int sdhci_suspend_host(struct sdhci_host *host)
{
        if (host->ops->platform_suspend)
                host->ops->platform_suspend(host);

        sdhci_disable_card_detection(host);

        /* Disable tuning since we are suspending */
        if (host->flags & SDHCI_USING_RETUNING_TIMER) {
                del_timer_sync(&host->tuning_timer);
                host->flags &= ~SDHCI_NEEDS_RETUNING;
        }

        if (!device_may_wakeup(mmc_dev(host->mmc))) {
                sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
                free_irq(host->irq, host);
        } else {
                sdhci_enable_irq_wakeups(host);
                enable_irq_wake(host->irq);
        }
        return 0;
}

EXPORT_SYMBOL_GPL(sdhci_suspend_host);

int sdhci_resume_host(struct sdhci_host *host)
{
        int ret = 0;

        if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
                if (host->ops->enable_dma)
                        host->ops->enable_dma(host);
        }

        if (!device_may_wakeup(mmc_dev(host->mmc))) {
                ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
                                  mmc_hostname(host->mmc), host);
                if (ret)
                        return ret;
        } else {
                sdhci_disable_irq_wakeups(host);
                disable_irq_wake(host->irq);
        }

        if ((host->mmc->pm_flags & MMC_PM_KEEP_POWER) &&
            (host->quirks2 & SDHCI_QUIRK2_HOST_OFF_CARD_ON)) {
                /* Card keeps power but host controller does not */
                sdhci_init(host, 0);
                host->pwr = 0;
                host->clock = 0;
                sdhci_do_set_ios(host, &host->mmc->ios);
        } else {
                sdhci_init(host, (host->mmc->pm_flags & MMC_PM_KEEP_POWER));
                mmiowb();
        }

        sdhci_enable_card_detection(host);

        if (host->ops->platform_resume)
                host->ops->platform_resume(host);

        /* Set the re-tuning expiration flag */
        if (host->flags & SDHCI_USING_RETUNING_TIMER)
                host->flags |= SDHCI_NEEDS_RETUNING;

        return ret;
}

EXPORT_SYMBOL_GPL(sdhci_resume_host);
#endif /* CONFIG_PM */

#ifdef CONFIG_PM_RUNTIME

static int sdhci_runtime_pm_get(struct sdhci_host *host)
{
        return pm_runtime_get_sync(host->mmc->parent);
}

static int sdhci_runtime_pm_put(struct sdhci_host *host)
{
        pm_runtime_mark_last_busy(host->mmc->parent);
        return pm_runtime_put_autosuspend(host->mmc->parent);
}

static void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
{
        if (host->runtime_suspended || host->bus_on)
                return;
        host->bus_on = true;
        pm_runtime_get_noresume(host->mmc->parent);
}

static void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
{
        if (host->runtime_suspended || !host->bus_on)
                return;
        host->bus_on = false;
        pm_runtime_put_noidle(host->mmc->parent);
}

int sdhci_runtime_suspend_host(struct sdhci_host *host)
{
        unsigned long flags;
        int ret = 0;

        /* Disable tuning since we are suspending */
        if (host->flags & SDHCI_USING_RETUNING_TIMER) {
                del_timer_sync(&host->tuning_timer);
                host->flags &= ~SDHCI_NEEDS_RETUNING;
        }

        spin_lock_irqsave(&host->lock, flags);
        sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
        spin_unlock_irqrestore(&host->lock, flags);

        synchronize_irq(host->irq);

        spin_lock_irqsave(&host->lock, flags);
        host->runtime_suspended = true;
        spin_unlock_irqrestore(&host->lock, flags);

        return ret;
}
EXPORT_SYMBOL_GPL(sdhci_runtime_suspend_host);

int sdhci_runtime_resume_host(struct sdhci_host *host)
{
        unsigned long flags;
        int ret = 0, host_flags = host->flags;

        if (host_flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
                if (host->ops->enable_dma)
                        host->ops->enable_dma(host);
        }

        sdhci_init(host, 0);

        /* Force clock and power re-program */
        host->pwr = 0;
        host->clock = 0;
        sdhci_do_set_ios(host, &host->mmc->ios);

        sdhci_do_start_signal_voltage_switch(host, &host->mmc->ios);
        if ((host_flags & SDHCI_PV_ENABLED) &&
                !(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN)) {
                spin_lock_irqsave(&host->lock, flags);
                sdhci_enable_preset_value(host, true);
                spin_unlock_irqrestore(&host->lock, flags);
        }

        /* Set the re-tuning expiration flag */
        if (host->flags & SDHCI_USING_RETUNING_TIMER)
                host->flags |= SDHCI_NEEDS_RETUNING;

        spin_lock_irqsave(&host->lock, flags);

        host->runtime_suspended = false;

        /* Enable SDIO IRQ */
        if ((host->flags & SDHCI_SDIO_IRQ_ENABLED))
                sdhci_enable_sdio_irq_nolock(host, true);

        /* Enable Card Detection */
        sdhci_enable_card_detection(host);

        spin_unlock_irqrestore(&host->lock, flags);

        return ret;
}
EXPORT_SYMBOL_GPL(sdhci_runtime_resume_host);

#endif

/*****************************************************************************\
 *                                                                           *
 * Device allocation/registration                                            *
 *                                                                           *
\*****************************************************************************/

struct sdhci_host *sdhci_alloc_host(struct device *dev,
        size_t priv_size)
{
        struct mmc_host *mmc;
        struct sdhci_host *host;

        WARN_ON(dev == NULL);

        mmc = mmc_alloc_host(sizeof(struct sdhci_host) + priv_size, dev);
        if (!mmc)
                return ERR_PTR(-ENOMEM);

        host = mmc_priv(mmc);
        host->mmc = mmc;

        return host;
}

EXPORT_SYMBOL_GPL(sdhci_alloc_host);

int sdhci_add_host(struct sdhci_host *host)
{
        struct mmc_host *mmc;
        u32 caps[2] = {0, 0};
        u32 max_current_caps;
        unsigned int ocr_avail;
        int ret;

        WARN_ON(host == NULL);
        if (host == NULL)
                return -EINVAL;

        mmc = host->mmc;

        if (debug_quirks)
                host->quirks = debug_quirks;
        if (debug_quirks2)
                host->quirks2 = debug_quirks2;

        sdhci_reset(host, SDHCI_RESET_ALL);

        host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
        host->version = (host->version & SDHCI_SPEC_VER_MASK)
                                >> SDHCI_SPEC_VER_SHIFT;
        if (host->version > SDHCI_SPEC_300) {
                pr_err("%s: Unknown controller version (%d). "
                        "You may experience problems.\n", mmc_hostname(mmc),
                        host->version);
        }

        caps[0] = (host->quirks & SDHCI_QUIRK_MISSING_CAPS) ? host->caps :
                sdhci_readl(host, SDHCI_CAPABILITIES);

        if (host->version >= SDHCI_SPEC_300)
                caps[1] = (host->quirks & SDHCI_QUIRK_MISSING_CAPS) ?
                        host->caps1 :
                        sdhci_readl(host, SDHCI_CAPABILITIES_1);

        if (host->quirks & SDHCI_QUIRK_FORCE_DMA)
                host->flags |= SDHCI_USE_SDMA;
        else if (!(caps[0] & SDHCI_CAN_DO_SDMA))
                DBG("Controller doesn't have SDMA capability\n");
        else
                host->flags |= SDHCI_USE_SDMA;

        if ((host->quirks & SDHCI_QUIRK_BROKEN_DMA) &&
                (host->flags & SDHCI_USE_SDMA)) {
                DBG("Disabling DMA as it is marked broken\n");
                host->flags &= ~SDHCI_USE_SDMA;
        }

        if ((host->version >= SDHCI_SPEC_200) &&
                (caps[0] & SDHCI_CAN_DO_ADMA2))
                host->flags |= SDHCI_USE_ADMA;

        if ((host->quirks & SDHCI_QUIRK_BROKEN_ADMA) &&
                (host->flags & SDHCI_USE_ADMA)) {
                DBG("Disabling ADMA as it is marked broken\n");
                host->flags &= ~SDHCI_USE_ADMA;
        }

        if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
                if (host->ops->enable_dma) {
                        if (host->ops->enable_dma(host)) {
                                pr_warning("%s: No suitable DMA "
                                        "available. Falling back to PIO.\n",
                                        mmc_hostname(mmc));
                                host->flags &=
                                        ~(SDHCI_USE_SDMA | SDHCI_USE_ADMA);
                        }
                }
        }

        if (host->flags & SDHCI_USE_ADMA) {
                /*
                 * We need to allocate descriptors for all sg entries
                 * (128) and potentially one alignment transfer for
                 * each of those entries.
                 */
                host->adma_desc = kmalloc((128 * 2 + 1) * 4, GFP_KERNEL);
                host->align_buffer = kmalloc(128 * 4, GFP_KERNEL);
                if (!host->adma_desc || !host->align_buffer) {
                        kfree(host->adma_desc);
                        kfree(host->align_buffer);
                        pr_warning("%s: Unable to allocate ADMA "
                                "buffers. Falling back to standard DMA.\n",
                                mmc_hostname(mmc));
                        host->flags &= ~SDHCI_USE_ADMA;
                }
        }

        /*
         * If we use DMA, then it's up to the caller to set the DMA
         * mask, but PIO does not need the hw shim so we set a new
         * mask here in that case.
         */
        if (!(host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA))) {
                host->dma_mask = DMA_BIT_MASK(64);
                mmc_dev(host->mmc)->dma_mask = &host->dma_mask;
        }

        if (host->version >= SDHCI_SPEC_300)
                host->max_clk = (caps[0] & SDHCI_CLOCK_V3_BASE_MASK)
                        >> SDHCI_CLOCK_BASE_SHIFT;
        else
                host->max_clk = (caps[0] & SDHCI_CLOCK_BASE_MASK)
                        >> SDHCI_CLOCK_BASE_SHIFT;

        host->max_clk *= 1000000;
        if (host->max_clk == 0 || host->quirks &
                        SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN) {
                if (!host->ops->get_max_clock) {
                        pr_err("%s: Hardware doesn't specify base clock "
                               "frequency.\n", mmc_hostname(mmc));
                        return -ENODEV;
                }
                host->max_clk = host->ops->get_max_clock(host);
        }

        /*
         * In case of Host Controller v3.00, find out whether clock
         * multiplier is supported.
         */
        host->clk_mul = (caps[1] & SDHCI_CLOCK_MUL_MASK) >>
                        SDHCI_CLOCK_MUL_SHIFT;

        /*
         * In case the value in Clock Multiplier is 0, then programmable
         * clock mode is not supported, otherwise the actual clock
         * multiplier is one more than the value of Clock Multiplier
         * in the Capabilities Register.
         */
        if (host->clk_mul)
                host->clk_mul += 1;

        /*
         * Set host parameters.
         */
        mmc->ops = &sdhci_ops;
        mmc->f_max = host->max_clk;
        if (host->ops->get_min_clock)
                mmc->f_min = host->ops->get_min_clock(host);
        else if (host->version >= SDHCI_SPEC_300) {
                if (host->clk_mul) {
                        mmc->f_min = (host->max_clk * host->clk_mul) / 1024;
                        mmc->f_max = host->max_clk * host->clk_mul;
                } else
                        mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
        } else
                mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;

        host->timeout_clk =
                (caps[0] & SDHCI_TIMEOUT_CLK_MASK) >> SDHCI_TIMEOUT_CLK_SHIFT;
        if (host->timeout_clk == 0) {
                if (host->ops->get_timeout_clock) {
                        host->timeout_clk = host->ops->get_timeout_clock(host);
                } else if (!(host->quirks &
                                SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
                        pr_err("%s: Hardware doesn't specify timeout clock "
                               "frequency.\n", mmc_hostname(mmc));
                        return -ENODEV;
                }
        }
        if (caps[0] & SDHCI_TIMEOUT_CLK_UNIT)
                host->timeout_clk *= 1000;

        if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
                host->timeout_clk = mmc->f_max / 1000;

        mmc->max_discard_to = (1 << 27) / host->timeout_clk;

        mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23;

        if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
                host->flags |= SDHCI_AUTO_CMD12;

        /* Auto-CMD23 stuff only works in ADMA or PIO. */
        if ((host->version >= SDHCI_SPEC_300) &&
            ((host->flags & SDHCI_USE_ADMA) ||
             !(host->flags & SDHCI_USE_SDMA))) {
                host->flags |= SDHCI_AUTO_CMD23;
                DBG("%s: Auto-CMD23 available\n", mmc_hostname(mmc));
        } else {
                DBG("%s: Auto-CMD23 unavailable\n", mmc_hostname(mmc));
        }

        /*
         * A controller may support 8-bit width, but the board itself
         * might not have the pins brought out.  Boards that support
         * 8-bit width must set "mmc->caps |= MMC_CAP_8_BIT_DATA;" in
         * their platform code before calling sdhci_add_host(), and we
         * won't assume 8-bit width for hosts without that CAP.
         */
        if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
                mmc->caps |= MMC_CAP_4_BIT_DATA;

        if (host->quirks2 & SDHCI_QUIRK2_HOST_NO_CMD23)
                mmc->caps &= ~MMC_CAP_CMD23;

        if (caps[0] & SDHCI_CAN_DO_HISPD)
                mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;

        if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) &&
            !(host->mmc->caps & MMC_CAP_NONREMOVABLE))
                mmc->caps |= MMC_CAP_NEEDS_POLL;

        /* If vqmmc regulator and no 1.8V signalling, then there's no UHS */
        host->vqmmc = regulator_get_optional(mmc_dev(mmc), "vqmmc");
        if (IS_ERR_OR_NULL(host->vqmmc)) {
                if (PTR_ERR(host->vqmmc) < 0) {
                        pr_info("%s: no vqmmc regulator found\n",
                                mmc_hostname(mmc));
                        host->vqmmc = NULL;
                }
        } else {
                ret = regulator_enable(host->vqmmc);
                if (!regulator_is_supported_voltage(host->vqmmc, 1700000,
                        1950000))
                        caps[1] &= ~(SDHCI_SUPPORT_SDR104 |
                                        SDHCI_SUPPORT_SDR50 |
                                        SDHCI_SUPPORT_DDR50);
                if (ret) {
                        pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
                                mmc_hostname(mmc), ret);
                        host->vqmmc = NULL;
                }
        }

        if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V)
                caps[1] &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
                       SDHCI_SUPPORT_DDR50);

        /* Any UHS-I mode in caps implies SDR12 and SDR25 support. */
        if (caps[1] & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
                       SDHCI_SUPPORT_DDR50))
                mmc->caps |= MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25;

        /* SDR104 supports also implies SDR50 support */
        if (caps[1] & SDHCI_SUPPORT_SDR104) {
                mmc->caps |= MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_SDR50;
                /* SD3.0: SDR104 is supported so (for eMMC) the caps2
                 * field can be promoted to support HS200.
                 */
                if (!(host->quirks2 & SDHCI_QUIRK2_BROKEN_HS200))
                        mmc->caps2 |= MMC_CAP2_HS200;
        } else if (caps[1] & SDHCI_SUPPORT_SDR50)
                mmc->caps |= MMC_CAP_UHS_SDR50;

        if (caps[1] & SDHCI_SUPPORT_DDR50)
                mmc->caps |= MMC_CAP_UHS_DDR50;

        /* Does the host need tuning for SDR50? */
        if (caps[1] & SDHCI_USE_SDR50_TUNING)
                host->flags |= SDHCI_SDR50_NEEDS_TUNING;

        /* Does the host need tuning for SDR104 / HS200? */
        if (mmc->caps2 & MMC_CAP2_HS200)
                host->flags |= SDHCI_SDR104_NEEDS_TUNING;

        /* Driver Type(s) (A, C, D) supported by the host */
        if (caps[1] & SDHCI_DRIVER_TYPE_A)
                mmc->caps |= MMC_CAP_DRIVER_TYPE_A;
        if (caps[1] & SDHCI_DRIVER_TYPE_C)
                mmc->caps |= MMC_CAP_DRIVER_TYPE_C;
        if (caps[1] & SDHCI_DRIVER_TYPE_D)
                mmc->caps |= MMC_CAP_DRIVER_TYPE_D;

        /* Initial value for re-tuning timer count */
        host->tuning_count = (caps[1] & SDHCI_RETUNING_TIMER_COUNT_MASK) >>
                              SDHCI_RETUNING_TIMER_COUNT_SHIFT;

        /*
         * In case Re-tuning Timer is not disabled, the actual value of
         * re-tuning timer will be 2 ^ (n - 1).
         */
        if (host->tuning_count)
                host->tuning_count = 1 << (host->tuning_count - 1);

        /* Re-tuning mode supported by the Host Controller */
        host->tuning_mode = (caps[1] & SDHCI_RETUNING_MODE_MASK) >>
                             SDHCI_RETUNING_MODE_SHIFT;

        ocr_avail = 0;

        host->vmmc = regulator_get_optional(mmc_dev(mmc), "vmmc");
        if (IS_ERR_OR_NULL(host->vmmc)) {
                if (PTR_ERR(host->vmmc) < 0) {
                        pr_info("%s: no vmmc regulator found\n",
                                mmc_hostname(mmc));
                        host->vmmc = NULL;
                }
        }

#ifdef CONFIG_REGULATOR
        /*
         * Voltage range check makes sense only if regulator reports
         * any voltage value.
         */
        if (host->vmmc && regulator_get_voltage(host->vmmc) > 0) {
                ret = regulator_is_supported_voltage(host->vmmc, 2700000,
                        3600000);
                if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_330)))
                        caps[0] &= ~SDHCI_CAN_VDD_330;
                if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_300)))
                        caps[0] &= ~SDHCI_CAN_VDD_300;
                ret = regulator_is_supported_voltage(host->vmmc, 1700000,
                        1950000);
                if ((ret <= 0) || (!(caps[0] & SDHCI_CAN_VDD_180)))
                        caps[0] &= ~SDHCI_CAN_VDD_180;
        }
#endif /* CONFIG_REGULATOR */

        /*
         * According to SD Host Controller spec v3.00, if the Host System
         * can afford more than 150mA, Host Driver should set XPC to 1. Also
         * the value is meaningful only if Voltage Support in the Capabilities
         * register is set. The actual current value is 4 times the register
         * value.
         */
        max_current_caps = sdhci_readl(host, SDHCI_MAX_CURRENT);
        if (!max_current_caps && host->vmmc) {
                u32 curr = regulator_get_current_limit(host->vmmc);
                if (curr > 0) {

                        /* convert to SDHCI_MAX_CURRENT format */
                        curr = curr/1000;  /* convert to mA */
                        curr = curr/SDHCI_MAX_CURRENT_MULTIPLIER;

                        curr = min_t(u32, curr, SDHCI_MAX_CURRENT_LIMIT);
                        max_current_caps =
                                (curr << SDHCI_MAX_CURRENT_330_SHIFT) |
                                (curr << SDHCI_MAX_CURRENT_300_SHIFT) |
                                (curr << SDHCI_MAX_CURRENT_180_SHIFT);
                }
        }

        if (caps[0] & SDHCI_CAN_VDD_330) {
                ocr_avail |= MMC_VDD_32_33 | MMC_VDD_33_34;

                mmc->max_current_330 = ((max_current_caps &
                                   SDHCI_MAX_CURRENT_330_MASK) >>
                                   SDHCI_MAX_CURRENT_330_SHIFT) *
                                   SDHCI_MAX_CURRENT_MULTIPLIER;
        }
        if (caps[0] & SDHCI_CAN_VDD_300) {
                ocr_avail |= MMC_VDD_29_30 | MMC_VDD_30_31;

                mmc->max_current_300 = ((max_current_caps &
                                   SDHCI_MAX_CURRENT_300_MASK) >>
                                   SDHCI_MAX_CURRENT_300_SHIFT) *
                                   SDHCI_MAX_CURRENT_MULTIPLIER;
        }
        if (caps[0] & SDHCI_CAN_VDD_180) {
                ocr_avail |= MMC_VDD_165_195;

                mmc->max_current_180 = ((max_current_caps &
                                   SDHCI_MAX_CURRENT_180_MASK) >>
                                   SDHCI_MAX_CURRENT_180_SHIFT) *
                                   SDHCI_MAX_CURRENT_MULTIPLIER;
        }

        if (host->ocr_mask)
                ocr_avail = host->ocr_mask;

        mmc->ocr_avail = ocr_avail;
        mmc->ocr_avail_sdio = ocr_avail;
        if (host->ocr_avail_sdio)
                mmc->ocr_avail_sdio &= host->ocr_avail_sdio;
        mmc->ocr_avail_sd = ocr_avail;
        if (host->ocr_avail_sd)
                mmc->ocr_avail_sd &= host->ocr_avail_sd;
        else /* normal SD controllers don't support 1.8V */
                mmc->ocr_avail_sd &= ~MMC_VDD_165_195;
        mmc->ocr_avail_mmc = ocr_avail;
        if (host->ocr_avail_mmc)
                mmc->ocr_avail_mmc &= host->ocr_avail_mmc;

        if (mmc->ocr_avail == 0) {
                pr_err("%s: Hardware doesn't report any "
                        "support voltages.\n", mmc_hostname(mmc));
                return -ENODEV;
        }

        spin_lock_init(&host->lock);

        /*
         * Maximum number of segments. Depends on if the hardware
         * can do scatter/gather or not.
         */
        if (host->flags & SDHCI_USE_ADMA)
                mmc->max_segs = 128;
        else if (host->flags & SDHCI_USE_SDMA)
                mmc->max_segs = 1;
        else /* PIO */
                mmc->max_segs = 128;

        /*
         * Maximum number of sectors in one transfer. Limited by DMA boundary
         * size (512KiB).
         */
        mmc->max_req_size = 524288;

        /*
         * Maximum segment size. Could be one segment with the maximum number
         * of bytes. When doing hardware scatter/gather, each entry cannot
         * be larger than 64 KiB though.
         */
        if (host->flags & SDHCI_USE_ADMA) {
                if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC)
                        mmc->max_seg_size = 65535;
                else
                        mmc->max_seg_size = 65536;
        } else {
                mmc->max_seg_size = mmc->max_req_size;
        }

        /*
         * Maximum block size. This varies from controller to controller and
         * is specified in the capabilities register.
         */
        if (host->quirks & SDHCI_QUIRK_FORCE_BLK_SZ_2048) {
                mmc->max_blk_size = 2;
        } else {
                mmc->max_blk_size = (caps[0] & SDHCI_MAX_BLOCK_MASK) >>
                                SDHCI_MAX_BLOCK_SHIFT;
                if (mmc->max_blk_size >= 3) {
                        pr_warning("%s: Invalid maximum block size, "
                                "assuming 512 bytes\n", mmc_hostname(mmc));
                        mmc->max_blk_size = 0;
                }
        }

        mmc->max_blk_size = 512 << mmc->max_blk_size;

        /*
         * Maximum block count.
         */
        mmc->max_blk_count = (host->quirks & SDHCI_QUIRK_NO_MULTIBLOCK) ? 1 : 65535;

        /*
         * Init tasklets.
         */
        tasklet_init(&host->card_tasklet,
                sdhci_tasklet_card, (unsigned long)host);
        tasklet_init(&host->finish_tasklet,
                sdhci_tasklet_finish, (unsigned long)host);

        setup_timer(&host->timer, sdhci_timeout_timer, (unsigned long)host);

        if (host->version >= SDHCI_SPEC_300) {
                init_waitqueue_head(&host->buf_ready_int);

                /* Initialize re-tuning timer */
                init_timer(&host->tuning_timer);
                host->tuning_timer.data = (unsigned long)host;
                host->tuning_timer.function = sdhci_tuning_timer;
        }

        sdhci_init(host, 0);

        ret = request_irq(host->irq, sdhci_irq, IRQF_SHARED,
                mmc_hostname(mmc), host);
        if (ret) {
                pr_err("%s: Failed to request IRQ %d: %d\n",
                       mmc_hostname(mmc), host->irq, ret);
                goto untasklet;
        }

#ifdef CONFIG_MMC_DEBUG
        sdhci_dumpregs(host);
#endif

#ifdef SDHCI_USE_LEDS_CLASS
        snprintf(host->led_name, sizeof(host->led_name),
                "%s::", mmc_hostname(mmc));
        host->led.name = host->led_name;
        host->led.brightness = LED_OFF;
        host->led.default_trigger = mmc_hostname(mmc);
        host->led.brightness_set = sdhci_led_control;

        ret = led_classdev_register(mmc_dev(mmc), &host->led);
        if (ret) {
                pr_err("%s: Failed to register LED device: %d\n",
                       mmc_hostname(mmc), ret);
                goto reset;
        }
#endif

        mmiowb();

        mmc_add_host(mmc);

        pr_info("%s: SDHCI controller on %s [%s] using %s\n",
                mmc_hostname(mmc), host->hw_name, dev_name(mmc_dev(mmc)),
                (host->flags & SDHCI_USE_ADMA) ? "ADMA" :
                (host->flags & SDHCI_USE_SDMA) ? "DMA" : "PIO");

        sdhci_enable_card_detection(host);

        return 0;

#ifdef SDHCI_USE_LEDS_CLASS
reset:
        sdhci_reset(host, SDHCI_RESET_ALL);
        sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
        free_irq(host->irq, host);
#endif
untasklet:
        tasklet_kill(&host->card_tasklet);
        tasklet_kill(&host->finish_tasklet);

        return ret;
}

EXPORT_SYMBOL_GPL(sdhci_add_host);

void sdhci_remove_host(struct sdhci_host *host, int dead)
{
        unsigned long flags;

        if (dead) {
                spin_lock_irqsave(&host->lock, flags);

                host->flags |= SDHCI_DEVICE_DEAD;

                if (host->mrq) {
                        pr_err("%s: Controller removed during "
                                " transfer!\n", mmc_hostname(host->mmc));

                        host->mrq->cmd->error = -ENOMEDIUM;
                        tasklet_schedule(&host->finish_tasklet);
                }

                spin_unlock_irqrestore(&host->lock, flags);
        }

        sdhci_disable_card_detection(host);

        mmc_remove_host(host->mmc);

#ifdef SDHCI_USE_LEDS_CLASS
        led_classdev_unregister(&host->led);
#endif

        if (!dead)
                sdhci_reset(host, SDHCI_RESET_ALL);

        sdhci_mask_irqs(host, SDHCI_INT_ALL_MASK);
        free_irq(host->irq, host);

        del_timer_sync(&host->timer);

        tasklet_kill(&host->card_tasklet);
        tasklet_kill(&host->finish_tasklet);

        if (host->vmmc) {
                regulator_disable(host->vmmc);
                regulator_put(host->vmmc);
        }

        if (host->vqmmc) {
                regulator_disable(host->vqmmc);
                regulator_put(host->vqmmc);
        }

        kfree(host->adma_desc);
        kfree(host->align_buffer);

        host->adma_desc = NULL;
        host->align_buffer = NULL;
}

EXPORT_SYMBOL_GPL(sdhci_remove_host);

void sdhci_free_host(struct sdhci_host *host)
{
        mmc_free_host(host->mmc);
}

EXPORT_SYMBOL_GPL(sdhci_free_host);

/*****************************************************************************\
 *                                                                           *
 * Driver init/exit                                                          *
 *                                                                           *
\*****************************************************************************/

static int __init sdhci_drv_init(void)
{
        pr_info(DRIVER_NAME
                ": Secure Digital Host Controller Interface driver\n");
        pr_info(DRIVER_NAME ": Copyright(c) Pierre Ossman\n");

        return 0;
}

static void __exit sdhci_drv_exit(void)
{
}

module_init(sdhci_drv_init);
module_exit(sdhci_drv_exit);

module_param(debug_quirks, uint, 0444);
module_param(debug_quirks2, uint, 0444);

MODULE_AUTHOR("Pierre Ossman <pierre@ossman.eu>");
MODULE_DESCRIPTION("Secure Digital Host Controller Interface core driver");
MODULE_LICENSE("GPL");

MODULE_PARM_DESC(debug_quirks, "Force certain quirks.");
MODULE_PARM_DESC(debug_quirks2, "Force certain other quirks.");