// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  linux/drivers/mmc/host/sdhci.c - Secure Digital Host Controller Interface driver
 *
 *  Copyright (C) 2005-2008 Pierre Ossman, All Rights Reserved.
 *
 * Thanks to the following companies for their support:
 *
 *     - JMicron (hardware and technical support)
 */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/ktime.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/sizes.h>
#include <linux/swiotlb.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>

#include <linux/leds.h>

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

#include "sdhci.h"

#define DRIVER_NAME "sdhci"

#define DBG(f, x...) \
        pr_debug("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)

#define SDHCI_DUMP(f, x...) \
        pr_err("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)

#define MAX_TUNING_LOOP 40

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

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

static bool sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd);

void sdhci_dumpregs(struct sdhci_host *host)
{
        SDHCI_DUMP("============ SDHCI REGISTER DUMP ===========\n");

        SDHCI_DUMP("Sys addr:  0x%08x | Version:  0x%08x\n",
                   sdhci_readl(host, SDHCI_DMA_ADDRESS),
                   sdhci_readw(host, SDHCI_HOST_VERSION));
        SDHCI_DUMP("Blk size:  0x%08x | Blk cnt:  0x%08x\n",
                   sdhci_readw(host, SDHCI_BLOCK_SIZE),
                   sdhci_readw(host, SDHCI_BLOCK_COUNT));
        SDHCI_DUMP("Argument:  0x%08x | Trn mode: 0x%08x\n",
                   sdhci_readl(host, SDHCI_ARGUMENT),
                   sdhci_readw(host, SDHCI_TRANSFER_MODE));
        SDHCI_DUMP("Present:   0x%08x | Host ctl: 0x%08x\n",
                   sdhci_readl(host, SDHCI_PRESENT_STATE),
                   sdhci_readb(host, SDHCI_HOST_CONTROL));
        SDHCI_DUMP("Power:     0x%08x | Blk gap:  0x%08x\n",
                   sdhci_readb(host, SDHCI_POWER_CONTROL),
                   sdhci_readb(host, SDHCI_BLOCK_GAP_CONTROL));
        SDHCI_DUMP("Wake-up:   0x%08x | Clock:    0x%08x\n",
                   sdhci_readb(host, SDHCI_WAKE_UP_CONTROL),
                   sdhci_readw(host, SDHCI_CLOCK_CONTROL));
        SDHCI_DUMP("Timeout:   0x%08x | Int stat: 0x%08x\n",
                   sdhci_readb(host, SDHCI_TIMEOUT_CONTROL),
                   sdhci_readl(host, SDHCI_INT_STATUS));
        SDHCI_DUMP("Int enab:  0x%08x | Sig enab: 0x%08x\n",
                   sdhci_readl(host, SDHCI_INT_ENABLE),
                   sdhci_readl(host, SDHCI_SIGNAL_ENABLE));
        SDHCI_DUMP("ACmd stat: 0x%08x | Slot int: 0x%08x\n",
                   sdhci_readw(host, SDHCI_AUTO_CMD_STATUS),
                   sdhci_readw(host, SDHCI_SLOT_INT_STATUS));
        SDHCI_DUMP("Caps:      0x%08x | Caps_1:   0x%08x\n",
                   sdhci_readl(host, SDHCI_CAPABILITIES),
                   sdhci_readl(host, SDHCI_CAPABILITIES_1));
        SDHCI_DUMP("Cmd:       0x%08x | Max curr: 0x%08x\n",
                   sdhci_readw(host, SDHCI_COMMAND),
                   sdhci_readl(host, SDHCI_MAX_CURRENT));
        SDHCI_DUMP("Resp[0]:   0x%08x | Resp[1]:  0x%08x\n",
                   sdhci_readl(host, SDHCI_RESPONSE),
                   sdhci_readl(host, SDHCI_RESPONSE + 4));
        SDHCI_DUMP("Resp[2]:   0x%08x | Resp[3]:  0x%08x\n",
                   sdhci_readl(host, SDHCI_RESPONSE + 8),
                   sdhci_readl(host, SDHCI_RESPONSE + 12));
        SDHCI_DUMP("Host ctl2: 0x%08x\n",
                   sdhci_readw(host, SDHCI_HOST_CONTROL2));

        if (host->flags & SDHCI_USE_ADMA) {
                if (host->flags & SDHCI_USE_64_BIT_DMA) {
                        SDHCI_DUMP("ADMA Err:  0x%08x | ADMA Ptr: 0x%08x%08x\n",
                                   sdhci_readl(host, SDHCI_ADMA_ERROR),
                                   sdhci_readl(host, SDHCI_ADMA_ADDRESS_HI),
                                   sdhci_readl(host, SDHCI_ADMA_ADDRESS));
                } else {
                        SDHCI_DUMP("ADMA Err:  0x%08x | ADMA Ptr: 0x%08x\n",
                                   sdhci_readl(host, SDHCI_ADMA_ERROR),
                                   sdhci_readl(host, SDHCI_ADMA_ADDRESS));
                }
        }

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

        SDHCI_DUMP("============================================\n");
}
EXPORT_SYMBOL_GPL(sdhci_dumpregs);

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

static void sdhci_do_enable_v4_mode(struct sdhci_host *host)
{
        u16 ctrl2;

        ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
        if (ctrl2 & SDHCI_CTRL_V4_MODE)
                return;

        ctrl2 |= SDHCI_CTRL_V4_MODE;
        sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
}

/*
 * This can be called before sdhci_add_host() by Vendor's host controller
 * driver to enable v4 mode if supported.
 */
void sdhci_enable_v4_mode(struct sdhci_host *host)
{
        host->v4_mode = true;
        sdhci_do_enable_v4_mode(host);
}
EXPORT_SYMBOL_GPL(sdhci_enable_v4_mode);

static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
{
        return cmd->data || cmd->flags & MMC_RSP_BUSY;
}

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

        if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) ||
            !mmc_card_is_removable(host->mmc) || mmc_can_gpio_cd(host->mmc))
                return;

        if (enable) {
                present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
                                      SDHCI_CARD_PRESENT;

                host->ier |= present ? SDHCI_INT_CARD_REMOVE :
                                       SDHCI_INT_CARD_INSERT;
        } else {
                host->ier &= ~(SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT);
        }

        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
}

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_runtime_pm_bus_on(struct sdhci_host *host)
{
        if (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->bus_on)
                return;
        host->bus_on = false;
        pm_runtime_put_noidle(host->mmc->parent);
}

void sdhci_reset(struct sdhci_host *host, u8 mask)
{
        ktime_t timeout;

        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 = ktime_add_ms(ktime_get(), 100);

        /* hw clears the bit when it's done */
        while (1) {
                bool timedout = ktime_after(ktime_get(), timeout);

                if (!(sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask))
                        break;
                if (timedout) {
                        pr_err("%s: Reset 0x%x never completed.\n",
                                mmc_hostname(host->mmc), (int)mask);
                        sdhci_dumpregs(host);
                        return;
                }
                udelay(10);
        }
}
EXPORT_SYMBOL_GPL(sdhci_reset);

static void sdhci_do_reset(struct sdhci_host *host, u8 mask)
{
        if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
                struct mmc_host *mmc = host->mmc;

                if (!mmc->ops->get_cd(mmc))
                        return;
        }

        host->ops->reset(host, mask);

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

                /* Resetting the controller clears many */
                host->preset_enabled = false;
        }
}

static void sdhci_set_default_irqs(struct sdhci_host *host)
{
        host->ier = 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 (host->tuning_mode == SDHCI_TUNING_MODE_2 ||
            host->tuning_mode == SDHCI_TUNING_MODE_3)
                host->ier |= SDHCI_INT_RETUNE;

        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
}

static void sdhci_config_dma(struct sdhci_host *host)
{
        u8 ctrl;
        u16 ctrl2;

        if (host->version < SDHCI_SPEC_200)
                return;

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);

        /*
         * Always adjust the DMA selection as some controllers
         * (e.g. JMicron) can't do PIO properly when the selection
         * is ADMA.
         */
        ctrl &= ~SDHCI_CTRL_DMA_MASK;
        if (!(host->flags & SDHCI_REQ_USE_DMA))
                goto out;

        /* Note if DMA Select is zero then SDMA is selected */
        if (host->flags & SDHCI_USE_ADMA)
                ctrl |= SDHCI_CTRL_ADMA32;

        if (host->flags & SDHCI_USE_64_BIT_DMA) {
                /*
                 * If v4 mode, all supported DMA can be 64-bit addressing if
                 * controller supports 64-bit system address, otherwise only
                 * ADMA can support 64-bit addressing.
                 */
                if (host->v4_mode) {
                        ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                        ctrl2 |= SDHCI_CTRL_64BIT_ADDR;
                        sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
                } else if (host->flags & SDHCI_USE_ADMA) {
                        /*
                         * Don't need to undo SDHCI_CTRL_ADMA32 in order to
                         * set SDHCI_CTRL_ADMA64.
                         */
                        ctrl |= SDHCI_CTRL_ADMA64;
                }
        }

out:
        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}

static void sdhci_init(struct sdhci_host *host, int soft)
{
        struct mmc_host *mmc = host->mmc;
        unsigned long flags;

        if (soft)
                sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
        else
                sdhci_do_reset(host, SDHCI_RESET_ALL);

        if (host->v4_mode)
                sdhci_do_enable_v4_mode(host);

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

        host->cqe_on = false;

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

static void sdhci_reinit(struct sdhci_host *host)
{
        u32 cd = host->ier & (SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT);

        sdhci_init(host, 0);
        sdhci_enable_card_detection(host);

        /*
         * A change to the card detect bits indicates a change in present state,
         * refer sdhci_set_card_detection(). A card detect interrupt might have
         * been missed while the host controller was being reset, so trigger a
         * rescan to check.
         */
        if (cd != (host->ier & (SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT)))
                mmc_detect_change(host->mmc, msecs_to_jiffies(200));
}

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

        if (host->quirks & SDHCI_QUIRK_NO_LED)
                return;

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

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

        if (host->quirks & SDHCI_QUIRK_NO_LED)
                return;

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

#if IS_REACHABLE(CONFIG_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_led_deactivate(host);
        else
                __sdhci_led_activate(host);
out:
        spin_unlock_irqrestore(&host->lock, flags);
}

static int sdhci_led_register(struct sdhci_host *host)
{
        struct mmc_host *mmc = host->mmc;

        if (host->quirks & SDHCI_QUIRK_NO_LED)
                return 0;

        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;

        return led_classdev_register(mmc_dev(mmc), &host->led);
}

static void sdhci_led_unregister(struct sdhci_host *host)
{
        if (host->quirks & SDHCI_QUIRK_NO_LED)
                return;

        led_classdev_unregister(&host->led);
}

static inline void sdhci_led_activate(struct sdhci_host *host)
{
}

static inline void sdhci_led_deactivate(struct sdhci_host *host)
{
}

#else

static inline int sdhci_led_register(struct sdhci_host *host)
{
        return 0;
}

static inline void sdhci_led_unregister(struct sdhci_host *host)
{
}

static inline void sdhci_led_activate(struct sdhci_host *host)
{
        __sdhci_led_activate(host);
}

static inline void sdhci_led_deactivate(struct sdhci_host *host)
{
        __sdhci_led_deactivate(host);
}

#endif

static void sdhci_mod_timer(struct sdhci_host *host, struct mmc_request *mrq,
                            unsigned long timeout)
{
        if (sdhci_data_line_cmd(mrq->cmd))
                mod_timer(&host->data_timer, timeout);
        else
                mod_timer(&host->timer, timeout);
}

static void sdhci_del_timer(struct sdhci_host *host, struct mmc_request *mrq)
{
        if (sdhci_data_line_cmd(mrq->cmd))
                del_timer(&host->data_timer);
        else
                del_timer(&host->timer);
}

static inline bool sdhci_has_requests(struct sdhci_host *host)
{
        return host->cmd || host->data_cmd;
}

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

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

        DBG("PIO reading\n");

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

        local_irq_save(flags);

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

                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) {
                BUG_ON(!sg_miter_next(&host->sg_miter));

                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;

        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 int sdhci_pre_dma_transfer(struct sdhci_host *host,
                                  struct mmc_data *data, int cookie)
{
        int sg_count;

        /*
         * If the data buffers are already mapped, return the previous
         * dma_map_sg() result.
         */
        if (data->host_cookie == COOKIE_PRE_MAPPED)
                return data->sg_count;

        /* Bounce write requests to the bounce buffer */
        if (host->bounce_buffer) {
                unsigned int length = data->blksz * data->blocks;

                if (length > host->bounce_buffer_size) {
                        pr_err("%s: asked for transfer of %u bytes exceeds bounce buffer %u bytes\n",
                               mmc_hostname(host->mmc), length,
                               host->bounce_buffer_size);
                        return -EIO;
                }
                if (mmc_get_dma_dir(data) == DMA_TO_DEVICE) {
                        /* Copy the data to the bounce buffer */
                        if (host->ops->copy_to_bounce_buffer) {
                                host->ops->copy_to_bounce_buffer(host,
                                                                 data, length);
                        } else {
                                sg_copy_to_buffer(data->sg, data->sg_len,
                                                  host->bounce_buffer, length);
                        }
                }
                /* Switch ownership to the DMA */
                dma_sync_single_for_device(host->mmc->parent,
                                           host->bounce_addr,
                                           host->bounce_buffer_size,
                                           mmc_get_dma_dir(data));
                /* Just a dummy value */
                sg_count = 1;
        } else {
                /* Just access the data directly from memory */
                sg_count = dma_map_sg(mmc_dev(host->mmc),
                                      data->sg, data->sg_len,
                                      mmc_get_dma_dir(data));
        }

        if (sg_count == 0)
                return -ENOSPC;

        data->sg_count = sg_count;
        data->host_cookie = cookie;

        return sg_count;
}

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);
}

void sdhci_adma_write_desc(struct sdhci_host *host, void **desc,
                           dma_addr_t addr, int len, unsigned int cmd)
{
        struct sdhci_adma2_64_desc *dma_desc = *desc;

        /* 32-bit and 64-bit descriptors have these members in same position */
        dma_desc->cmd = cpu_to_le16(cmd);
        dma_desc->len = cpu_to_le16(len);
        dma_desc->addr_lo = cpu_to_le32(lower_32_bits(addr));

        if (host->flags & SDHCI_USE_64_BIT_DMA)
                dma_desc->addr_hi = cpu_to_le32(upper_32_bits(addr));

        *desc += host->desc_sz;
}
EXPORT_SYMBOL_GPL(sdhci_adma_write_desc);

static inline void __sdhci_adma_write_desc(struct sdhci_host *host,
                                           void **desc, dma_addr_t addr,
                                           int len, unsigned int cmd)
{
        if (host->ops->adma_write_desc)
                host->ops->adma_write_desc(host, desc, addr, len, cmd);
        else
                sdhci_adma_write_desc(host, desc, addr, len, cmd);
}

static void sdhci_adma_mark_end(void *desc)
{
        struct sdhci_adma2_64_desc *dma_desc = desc;

        /* 32-bit and 64-bit descriptors have 'cmd' in same position */
        dma_desc->cmd |= cpu_to_le16(ADMA2_END);
}

static void sdhci_adma_table_pre(struct sdhci_host *host,
        struct mmc_data *data, int sg_count)
{
        struct scatterlist *sg;
        unsigned long flags;
        dma_addr_t addr, align_addr;
        void *desc, *align;
        char *buffer;
        int len, offset, i;

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

        host->sg_count = sg_count;

        desc = host->adma_table;
        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 = (SDHCI_ADMA2_ALIGN - (addr & SDHCI_ADMA2_MASK)) &
                         SDHCI_ADMA2_MASK;
                if (offset) {
                        if (data->flags & MMC_DATA_WRITE) {
                                buffer = sdhci_kmap_atomic(sg, &flags);
                                memcpy(align, buffer, offset);
                                sdhci_kunmap_atomic(buffer, &flags);
                        }

                        /* tran, valid */
                        __sdhci_adma_write_desc(host, &desc, align_addr,
                                                offset, ADMA2_TRAN_VALID);

                        BUG_ON(offset > 65536);

                        align += SDHCI_ADMA2_ALIGN;
                        align_addr += SDHCI_ADMA2_ALIGN;

                        addr += offset;
                        len -= offset;
                }

                BUG_ON(len > 65536);

                /* tran, valid */
                if (len)
                        __sdhci_adma_write_desc(host, &desc, addr, len,
                                                ADMA2_TRAN_VALID);

                /*
                 * If this triggers then we have a calculation bug
                 * somewhere. :/
                 */
                WARN_ON((desc - host->adma_table) >= host->adma_table_sz);
        }

        if (host->quirks & SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC) {
                /* Mark the last descriptor as the terminating descriptor */
                if (desc != host->adma_table) {
                        desc -= host->desc_sz;
                        sdhci_adma_mark_end(desc);
                }
        } else {
                /* Add a terminating entry - nop, end, valid */
                __sdhci_adma_write_desc(host, &desc, 0, 0, ADMA2_NOP_END_VALID);
        }
}

static void sdhci_adma_table_post(struct sdhci_host *host,
        struct mmc_data *data)
{
        struct scatterlist *sg;
        int i, size;
        void *align;
        char *buffer;
        unsigned long flags;

        if (data->flags & MMC_DATA_READ) {
                bool has_unaligned = false;

                /* Do a quick scan of the SG list for any unaligned mappings */
                for_each_sg(data->sg, sg, host->sg_count, i)
                        if (sg_dma_address(sg) & SDHCI_ADMA2_MASK) {
                                has_unaligned = true;
                                break;
                        }

                if (has_unaligned) {
                        dma_sync_sg_for_cpu(mmc_dev(host->mmc), data->sg,
                                            data->sg_len, DMA_FROM_DEVICE);

                        align = host->align_buffer;

                        for_each_sg(data->sg, sg, host->sg_count, i) {
                                if (sg_dma_address(sg) & SDHCI_ADMA2_MASK) {
                                        size = SDHCI_ADMA2_ALIGN -
                                               (sg_dma_address(sg) & SDHCI_ADMA2_MASK);

                                        buffer = sdhci_kmap_atomic(sg, &flags);
                                        memcpy(buffer, align, size);
                                        sdhci_kunmap_atomic(buffer, &flags);

                                        align += SDHCI_ADMA2_ALIGN;
                                }
                        }
                }
        }
}

static void sdhci_set_adma_addr(struct sdhci_host *host, dma_addr_t addr)
{
        sdhci_writel(host, lower_32_bits(addr), SDHCI_ADMA_ADDRESS);
        if (host->flags & SDHCI_USE_64_BIT_DMA)
                sdhci_writel(host, upper_32_bits(addr), SDHCI_ADMA_ADDRESS_HI);
}

static dma_addr_t sdhci_sdma_address(struct sdhci_host *host)
{
        if (host->bounce_buffer)
                return host->bounce_addr;
        else
                return sg_dma_address(host->data->sg);
}

static void sdhci_set_sdma_addr(struct sdhci_host *host, dma_addr_t addr)
{
        if (host->v4_mode)
                sdhci_set_adma_addr(host, addr);
        else
                sdhci_writel(host, addr, SDHCI_DMA_ADDRESS);
}

static unsigned int sdhci_target_timeout(struct sdhci_host *host,
                                         struct mmc_command *cmd,
                                         struct mmc_data *data)
{
        unsigned int target_timeout;

        /* timeout in us */
        if (!data) {
                target_timeout = cmd->busy_timeout * 1000;
        } else {
                target_timeout = DIV_ROUND_UP(data->timeout_ns, 1000);
                if (host->clock && data->timeout_clks) {
                        unsigned long long val;

                        /*
                         * data->timeout_clks is in units of clock cycles.
                         * host->clock is in Hz.  target_timeout is in us.
                         * Hence, us = 1000000 * cycles / Hz.  Round up.
                         */
                        val = 1000000ULL * data->timeout_clks;
                        if (do_div(val, host->clock))
                                target_timeout++;
                        target_timeout += val;
                }
        }

        return target_timeout;
}

static void sdhci_calc_sw_timeout(struct sdhci_host *host,
                                  struct mmc_command *cmd)
{
        struct mmc_data *data = cmd->data;
        struct mmc_host *mmc = host->mmc;
        struct mmc_ios *ios = &mmc->ios;
        unsigned char bus_width = 1 << ios->bus_width;
        unsigned int blksz;
        unsigned int freq;
        u64 target_timeout;
        u64 transfer_time;

        target_timeout = sdhci_target_timeout(host, cmd, data);
        target_timeout *= NSEC_PER_USEC;

        if (data) {
                blksz = data->blksz;
                freq = host->mmc->actual_clock ? : host->clock;
                transfer_time = (u64)blksz * NSEC_PER_SEC * (8 / bus_width);
                do_div(transfer_time, freq);
                /* multiply by '2' to account for any unknowns */
                transfer_time = transfer_time * 2;
                /* calculate timeout for the entire data */
                host->data_timeout = data->blocks * target_timeout +
                                     transfer_time;
        } else {
                host->data_timeout = target_timeout;
        }

        if (host->data_timeout)
                host->data_timeout += MMC_CMD_TRANSFER_TIME;
}

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

        *too_big = true;

        /*
         * 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 command, asume max */
        if (cmd == NULL)
                return 0xE;

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

        /* timeout in us */
        target_timeout = sdhci_target_timeout(host, cmd, data);

        /*
         * 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) {
                if (!(host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT))
                        DBG("Too large timeout 0x%x requested for CMD%d!\n",
                            count, cmd->opcode);
                count = 0xE;
        } else {
                *too_big = false;
        }

        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)
                host->ier = (host->ier & ~pio_irqs) | dma_irqs;
        else
                host->ier = (host->ier & ~dma_irqs) | pio_irqs;

        if (host->flags & (SDHCI_AUTO_CMD23 | SDHCI_AUTO_CMD12))
                host->ier |= SDHCI_INT_AUTO_CMD_ERR;
        else

                host->ier &= ~SDHCI_INT_AUTO_CMD_ERR;

        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
}

void sdhci_set_data_timeout_irq(struct sdhci_host *host, bool enable)
{
        if (enable)
                host->ier |= SDHCI_INT_DATA_TIMEOUT;
        else
                host->ier &= ~SDHCI_INT_DATA_TIMEOUT;
        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
}
EXPORT_SYMBOL_GPL(sdhci_set_data_timeout_irq);

void __sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
        bool too_big = false;
        u8 count = sdhci_calc_timeout(host, cmd, &too_big);

        if (too_big &&
            host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT) {
                sdhci_calc_sw_timeout(host, cmd);
                sdhci_set_data_timeout_irq(host, false);
        } else if (!(host->ier & SDHCI_INT_DATA_TIMEOUT)) {
                sdhci_set_data_timeout_irq(host, true);
        }

        sdhci_writeb(host, count, SDHCI_TIMEOUT_CONTROL);
}
EXPORT_SYMBOL_GPL(__sdhci_set_timeout);

static void sdhci_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
{
        if (host->ops->set_timeout)
                host->ops->set_timeout(host, cmd);
        else
                __sdhci_set_timeout(host, cmd);
}

static void sdhci_initialize_data(struct sdhci_host *host,
                                  struct mmc_data *data)
{
        WARN_ON(host->data);

        /* 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;
}

static inline void sdhci_set_block_info(struct sdhci_host *host,
                                        struct mmc_data *data)
{
        /* Set the DMA boundary value and block size */
        sdhci_writew(host,
                     SDHCI_MAKE_BLKSZ(host->sdma_boundary, data->blksz),
                     SDHCI_BLOCK_SIZE);
        /*
         * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count
         * can be supported, in that case 16-bit block count register must be 0.
         */
        if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
            (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) {
                if (sdhci_readw(host, SDHCI_BLOCK_COUNT))
                        sdhci_writew(host, 0, SDHCI_BLOCK_COUNT);
                sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT);
        } else {
                sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
        }
}

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

        sdhci_initialize_data(host, data);

        if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
                struct scatterlist *sg;
                unsigned int length_mask, offset_mask;
                int i;

                host->flags |= SDHCI_REQ_USE_DMA;

                /*
                 * FIXME: This doesn't account for merging when mapping the
                 * scatterlist.
                 *
                 * The assumption here being that alignment and lengths are
                 * the same after DMA mapping to device address space.
                 */
                length_mask = 0;
                offset_mask = 0;
                if (host->flags & SDHCI_USE_ADMA) {
                        if (host->quirks & SDHCI_QUIRK_32BIT_ADMA_SIZE) {
                                length_mask = 3;
                                /*
                                 * As we use up to 3 byte chunks to work
                                 * around alignment problems, we need to
                                 * check the offset as well.
                                 */
                                offset_mask = 3;
                        }
                } else {
                        if (host->quirks & SDHCI_QUIRK_32BIT_DMA_SIZE)
                                length_mask = 3;
                        if (host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR)
                                offset_mask = 3;
                }

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

        if (host->flags & SDHCI_REQ_USE_DMA) {
                int sg_cnt = sdhci_pre_dma_transfer(host, data, COOKIE_MAPPED);

                if (sg_cnt <= 0) {
                        /*
                         * This only happens when someone fed
                         * us an invalid request.
                         */
                        WARN_ON(1);
                        host->flags &= ~SDHCI_REQ_USE_DMA;
                } else if (host->flags & SDHCI_USE_ADMA) {
                        sdhci_adma_table_pre(host, data, sg_cnt);
                        sdhci_set_adma_addr(host, host->adma_addr);
                } else {
                        WARN_ON(sg_cnt != 1);
                        sdhci_set_sdma_addr(host, sdhci_sdma_address(host));
                }
        }

        sdhci_config_dma(host);

        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);

        sdhci_set_block_info(host, data);
}

#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)

static int sdhci_external_dma_init(struct sdhci_host *host)
{
        int ret = 0;
        struct mmc_host *mmc = host->mmc;

        host->tx_chan = dma_request_chan(mmc->parent, "tx");
        if (IS_ERR(host->tx_chan)) {
                ret = PTR_ERR(host->tx_chan);
                if (ret != -EPROBE_DEFER)
                        pr_warn("Failed to request TX DMA channel.\n");
                host->tx_chan = NULL;
                return ret;
        }

        host->rx_chan = dma_request_chan(mmc->parent, "rx");
        if (IS_ERR(host->rx_chan)) {
                if (host->tx_chan) {
                        dma_release_channel(host->tx_chan);
                        host->tx_chan = NULL;
                }

                ret = PTR_ERR(host->rx_chan);
                if (ret != -EPROBE_DEFER)
                        pr_warn("Failed to request RX DMA channel.\n");
                host->rx_chan = NULL;
        }

        return ret;
}

static struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
                                                   struct mmc_data *data)
{
        return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
}

static int sdhci_external_dma_setup(struct sdhci_host *host,
                                    struct mmc_command *cmd)
{
        int ret, i;
        enum dma_transfer_direction dir;
        struct dma_async_tx_descriptor *desc;
        struct mmc_data *data = cmd->data;
        struct dma_chan *chan;
        struct dma_slave_config cfg;
        dma_cookie_t cookie;
        int sg_cnt;

        if (!host->mapbase)
                return -EINVAL;

        cfg.src_addr = host->mapbase + SDHCI_BUFFER;
        cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.src_maxburst = data->blksz / 4;
        cfg.dst_maxburst = data->blksz / 4;

        /* Sanity check: all the SG entries must be aligned by block size. */
        for (i = 0; i < data->sg_len; i++) {
                if ((data->sg + i)->length % data->blksz)
                        return -EINVAL;
        }

        chan = sdhci_external_dma_channel(host, data);

        ret = dmaengine_slave_config(chan, &cfg);
        if (ret)
                return ret;

        sg_cnt = sdhci_pre_dma_transfer(host, data, COOKIE_MAPPED);
        if (sg_cnt <= 0)
                return -EINVAL;

        dir = data->flags & MMC_DATA_WRITE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
        desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len, dir,
                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!desc)
                return -EINVAL;

        desc->callback = NULL;
        desc->callback_param = NULL;

        cookie = dmaengine_submit(desc);
        if (dma_submit_error(cookie))
                ret = cookie;

        return ret;
}

static void sdhci_external_dma_release(struct sdhci_host *host)
{
        if (host->tx_chan) {
                dma_release_channel(host->tx_chan);
                host->tx_chan = NULL;
        }

        if (host->rx_chan) {
                dma_release_channel(host->rx_chan);
                host->rx_chan = NULL;
        }

        sdhci_switch_external_dma(host, false);
}

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

        sdhci_initialize_data(host, data);

        host->flags |= SDHCI_REQ_USE_DMA;
        sdhci_set_transfer_irqs(host);

        sdhci_set_block_info(host, data);
}

static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
                                            struct mmc_command *cmd)
{
        if (!sdhci_external_dma_setup(host, cmd)) {
                __sdhci_external_dma_prepare_data(host, cmd);
        } else {
                sdhci_external_dma_release(host);
                pr_err("%s: Cannot use external DMA, switch to the DMA/PIO which standard SDHCI provides.\n",
                       mmc_hostname(host->mmc));
                sdhci_prepare_data(host, cmd);
        }
}

static void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
                                            struct mmc_command *cmd)
{
        struct dma_chan *chan;

        if (!cmd->data)
                return;

        chan = sdhci_external_dma_channel(host, cmd->data);
        if (chan)
                dma_async_issue_pending(chan);
}

#else

static inline int sdhci_external_dma_init(struct sdhci_host *host)
{
        return -EOPNOTSUPP;
}

static inline void sdhci_external_dma_release(struct sdhci_host *host)
{
}

static inline void sdhci_external_dma_prepare_data(struct sdhci_host *host,
                                                   struct mmc_command *cmd)
{
        /* This should never happen */
        WARN_ON_ONCE(1);
}

static inline void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
                                                   struct mmc_command *cmd)
{
}

static inline struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
                                                          struct mmc_data *data)
{
        return NULL;
}

#endif

void sdhci_switch_external_dma(struct sdhci_host *host, bool en)
{
        host->use_external_dma = en;
}
EXPORT_SYMBOL_GPL(sdhci_switch_external_dma);

static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
                                    struct mmc_request *mrq)
{
        return !mrq->sbc && (host->flags & SDHCI_AUTO_CMD12) &&
               !mrq->cap_cmd_during_tfr;
}

static inline bool sdhci_auto_cmd23(struct sdhci_host *host,
                                    struct mmc_request *mrq)
{
        return mrq->sbc && (host->flags & SDHCI_AUTO_CMD23);
}

static inline bool sdhci_manual_cmd23(struct sdhci_host *host,
                                      struct mmc_request *mrq)
{
        return mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23);
}

static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
                                         struct mmc_command *cmd,
                                         u16 *mode)
{
        bool use_cmd12 = sdhci_auto_cmd12(host, cmd->mrq) &&
                         (cmd->opcode != SD_IO_RW_EXTENDED);
        bool use_cmd23 = sdhci_auto_cmd23(host, cmd->mrq);
        u16 ctrl2;

        /*
         * In case of Version 4.10 or later, use of 'Auto CMD Auto
         * Select' is recommended rather than use of 'Auto CMD12
         * Enable' or 'Auto CMD23 Enable'. We require Version 4 Mode
         * here because some controllers (e.g sdhci-of-dwmshc) expect it.
         */
        if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
            (use_cmd12 || use_cmd23)) {
                *mode |= SDHCI_TRNS_AUTO_SEL;

                ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                if (use_cmd23)
                        ctrl2 |= SDHCI_CMD23_ENABLE;
                else
                        ctrl2 &= ~SDHCI_CMD23_ENABLE;
                sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);

                return;
        }

        /*
         * If we are sending CMD23, CMD12 never gets sent
         * on successful completion (so no Auto-CMD12).
         */
        if (use_cmd12)
                *mode |= SDHCI_TRNS_AUTO_CMD12;
        else if (use_cmd23)
                *mode |= SDHCI_TRNS_AUTO_CMD23;
}

static void sdhci_set_transfer_mode(struct sdhci_host *host,
        struct mmc_command *cmd)
{
        u16 mode = 0;
        struct mmc_data *data = cmd->data;

        if (data == NULL) {
                if (host->quirks2 &
                        SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD) {
                        /* must not clear SDHCI_TRANSFER_MODE when tuning */
                        if (cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
                                sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
                } else {
                /* 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);

        if (!(host->quirks2 & SDHCI_QUIRK2_SUPPORT_SINGLE))
                mode = SDHCI_TRNS_BLK_CNT_EN;

        if (mmc_op_multi(cmd->opcode) || data->blocks > 1) {
                mode = SDHCI_TRNS_BLK_CNT_EN | SDHCI_TRNS_MULTI;
                sdhci_auto_cmd_select(host, cmd, &mode);
                if (sdhci_auto_cmd23(host, cmd->mrq))
                        sdhci_writel(host, cmd->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 bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
{
        return (!(host->flags & SDHCI_DEVICE_DEAD) &&
                ((mrq->cmd && mrq->cmd->error) ||
                 (mrq->sbc && mrq->sbc->error) ||
                 (mrq->data && mrq->data->stop && mrq->data->stop->error) ||
                 (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST)));
}

static void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq)
{
        int i;

        for (i = 0; i < SDHCI_MAX_MRQS; i++) {
                if (host->mrqs_done[i] == mrq) {
                        WARN_ON(1);
                        return;
                }
        }

        for (i = 0; i < SDHCI_MAX_MRQS; i++) {
                if (!host->mrqs_done[i]) {
                        host->mrqs_done[i] = mrq;
                        break;
                }
        }

        WARN_ON(i >= SDHCI_MAX_MRQS);
}

static void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
{
        if (host->cmd && host->cmd->mrq == mrq)
                host->cmd = NULL;

        if (host->data_cmd && host->data_cmd->mrq == mrq)
                host->data_cmd = NULL;

        if (host->deferred_cmd && host->deferred_cmd->mrq == mrq)
                host->deferred_cmd = NULL;

        if (host->data && host->data->mrq == mrq)
                host->data = NULL;

        if (sdhci_needs_reset(host, mrq))
                host->pending_reset = true;

        sdhci_set_mrq_done(host, mrq);

        sdhci_del_timer(host, mrq);

        if (!sdhci_has_requests(host))
                sdhci_led_deactivate(host);
}

static void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
{
        __sdhci_finish_mrq(host, mrq);

        queue_work(host->complete_wq, &host->complete_work);
}

static void __sdhci_finish_data(struct sdhci_host *host, bool sw_data_timeout)
{
        struct mmc_command *data_cmd = host->data_cmd;
        struct mmc_data *data = host->data;

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

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

        if ((host->flags & (SDHCI_REQ_USE_DMA | SDHCI_USE_ADMA)) ==
            (SDHCI_REQ_USE_DMA | SDHCI_USE_ADMA))
                sdhci_adma_table_post(host, data);

        /*
         * 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 not using auto CMD12 (no CMD23)
         * b) error in multiblock transfer
         */
        if (data->stop &&
            ((!data->mrq->sbc && !sdhci_auto_cmd12(host, data->mrq)) ||
             data->error)) {
                /*
                 * 'cap_cmd_during_tfr' request must not use the command line
                 * after mmc_command_done() has been called. It is upper layer's
                 * responsibility to send the stop command if required.
                 */
                if (data->mrq->cap_cmd_during_tfr) {
                        __sdhci_finish_mrq(host, data->mrq);
                } else {
                        /* Avoid triggering warning in sdhci_send_command() */
                        host->cmd = NULL;
                        if (!sdhci_send_command(host, data->stop)) {
                                if (sw_data_timeout) {
                                        /*
                                         * This is anyway a sw data timeout, so
                                         * give up now.
                                         */
                                        data->stop->error = -EIO;
                                        __sdhci_finish_mrq(host, data->mrq);
                                } else {
                                        WARN_ON(host->deferred_cmd);
                                        host->deferred_cmd = data->stop;
                                }
                        }
                }
        } else {
                __sdhci_finish_mrq(host, data->mrq);
        }
}

static void sdhci_finish_data(struct sdhci_host *host)
{
        __sdhci_finish_data(host, false);
}

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

        WARN_ON(host->cmd);

        /* Initially, a command has no error */
        cmd->error = 0;

        if ((host->quirks2 & SDHCI_QUIRK2_STOP_WITH_TC) &&
            cmd->opcode == MMC_STOP_TRANSMISSION)
                cmd->flags |= MMC_RSP_BUSY;

        mask = SDHCI_CMD_INHIBIT;
        if (sdhci_data_line_cmd(cmd))
                mask |= SDHCI_DATA_INHIBIT;

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

        if (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask)
                return false;

        host->cmd = cmd;
        host->data_timeout = 0;
        if (sdhci_data_line_cmd(cmd)) {
                WARN_ON(host->data_cmd);
                host->data_cmd = cmd;
                sdhci_set_timeout(host, cmd);
        }

        if (cmd->data) {
                if (host->use_external_dma)
                        sdhci_external_dma_prepare_data(host, cmd);
                else
                        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)) {
                WARN_ONCE(1, "Unsupported response type!\n");
                /*
                 * This does not happen in practice because 136-bit response
                 * commands never have busy waiting, so rather than complicate
                 * the error path, just remove busy waiting and continue.
                 */
                cmd->flags &= ~MMC_RSP_BUSY;
        }

        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;

        timeout = jiffies;
        if (host->data_timeout)
                timeout += nsecs_to_jiffies(host->data_timeout);
        else if (!cmd->data && cmd->busy_timeout > 9000)
                timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
        else
                timeout += 10 * HZ;
        sdhci_mod_timer(host, cmd->mrq, timeout);

        if (host->use_external_dma)
                sdhci_external_dma_pre_transfer(host, cmd);

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

        return true;
}

static bool sdhci_present_error(struct sdhci_host *host,
                                struct mmc_command *cmd, bool present)
{
        if (!present || host->flags & SDHCI_DEVICE_DEAD) {
                cmd->error = -ENOMEDIUM;
                return true;
        }

        return false;
}

static bool sdhci_send_command_retry(struct sdhci_host *host,
                                     struct mmc_command *cmd,
                                     unsigned long flags)
        __releases(host->lock)
        __acquires(host->lock)
{
        struct mmc_command *deferred_cmd = host->deferred_cmd;
        int timeout = 10; /* Approx. 10 ms */
        bool present;

        while (!sdhci_send_command(host, cmd)) {
                if (!timeout--) {
                        pr_err("%s: Controller never released inhibit bit(s).\n",
                               mmc_hostname(host->mmc));
                        sdhci_dumpregs(host);
                        cmd->error = -EIO;
                        return false;
                }

                spin_unlock_irqrestore(&host->lock, flags);

                usleep_range(1000, 1250);

                present = host->mmc->ops->get_cd(host->mmc);

                spin_lock_irqsave(&host->lock, flags);

                /* A deferred command might disappear, handle that */
                if (cmd == deferred_cmd && cmd != host->deferred_cmd)
                        return true;

                if (sdhci_present_error(host, cmd, present))
                        return false;
        }

        if (cmd == host->deferred_cmd)
                host->deferred_cmd = NULL;

        return true;
}

static void sdhci_read_rsp_136(struct sdhci_host *host, struct mmc_command *cmd)
{
        int i, reg;

        for (i = 0; i < 4; i++) {
                reg = SDHCI_RESPONSE + (3 - i) * 4;
                cmd->resp[i] = sdhci_readl(host, reg);
        }

        if (host->quirks2 & SDHCI_QUIRK2_RSP_136_HAS_CRC)
                return;

        /* CRC is stripped so we need to do some shifting */
        for (i = 0; i < 4; i++) {
                cmd->resp[i] <<= 8;
                if (i != 3)
                        cmd->resp[i] |= cmd->resp[i + 1] >> 24;
        }
}

static void sdhci_finish_command(struct sdhci_host *host)
{
        struct mmc_command *cmd = host->cmd;

        host->cmd = NULL;

        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        sdhci_read_rsp_136(host, cmd);
                } else {
                        cmd->resp[0] = sdhci_readl(host, SDHCI_RESPONSE);
                }
        }

        if (cmd->mrq->cap_cmd_during_tfr && cmd == cmd->mrq->cmd)
                mmc_command_done(host->mmc, cmd->mrq);

        /*
         * The host can send and interrupt when the busy state has
         * ended, allowing us to wait without wasting CPU cycles.
         * The busy signal uses DAT0 so this is similar to waiting
         * for data to complete.
         *
         * Note: The 1.0 specification is a bit ambiguous about this
         *       feature so there might be some problems with older
         *       controllers.
         */
        if (cmd->flags & MMC_RSP_BUSY) {
                if (cmd->data) {
                        DBG("Cannot wait for busy signal when also doing a data transfer");
                } else if (!(host->quirks & SDHCI_QUIRK_NO_BUSY_IRQ) &&
                           cmd == host->data_cmd) {
                        /* Command complete before busy is ended */
                        return;
                }
        }

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

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

                if (!cmd->data)
                        __sdhci_finish_mrq(host, cmd->mrq);
        }
}

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

        switch (host->timing) {
        case MMC_TIMING_UHS_SDR12:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR12);
                break;
        case MMC_TIMING_UHS_SDR25:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR25);
                break;
        case MMC_TIMING_UHS_SDR50:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR50);
                break;
        case MMC_TIMING_UHS_SDR104:
        case MMC_TIMING_MMC_HS200:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_SDR104);
                break;
        case MMC_TIMING_UHS_DDR50:
        case MMC_TIMING_MMC_DDR52:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_DDR50);
                break;
        case MMC_TIMING_MMC_HS400:
                preset = sdhci_readw(host, SDHCI_PRESET_FOR_HS400);
                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;
}

u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
                   unsigned int *actual_clock)
{
        int div = 0; /* Initialized for compiler warning */
        int real_div = div, clk_mul = 1;
        u16 clk = 0;
        bool switch_base_clk = false;

        if (host->version >= SDHCI_SPEC_300) {
                if (host->preset_enabled) {
                        u16 pre_val;

                        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                        pre_val = sdhci_get_preset_value(host);
                        div = FIELD_GET(SDHCI_PRESET_SDCLK_FREQ_MASK, pre_val);
                        if (host->clk_mul &&
                                (pre_val & SDHCI_PRESET_CLKGEN_SEL)) {
                                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;
                        }
                        if ((host->max_clk * host->clk_mul / div) <= clock) {
                                /*
                                 * Set Programmable Clock Mode in the Clock
                                 * Control register.
                                 */
                                clk = SDHCI_PROG_CLOCK_MODE;
                                real_div = div;
                                clk_mul = host->clk_mul;
                                div--;
                        } else {
                                /*
                                 * Divisor can be too small to reach clock
                                 * speed requirement. Then use the base clock.
                                 */
                                switch_base_clk = true;
                        }
                }

                if (!host->clk_mul || switch_base_clk) {
                        /* 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;
                        if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
                                && !div && host->max_clk <= 25000000)
                                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)
                *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;

        return clk;
}
EXPORT_SYMBOL_GPL(sdhci_calc_clk);

void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
{
        ktime_t timeout;

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

        /* Wait max 150 ms */
        timeout = ktime_add_ms(ktime_get(), 150);
        while (1) {
                bool timedout = ktime_after(ktime_get(), timeout);

                clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                if (clk & SDHCI_CLOCK_INT_STABLE)
                        break;
                if (timedout) {
                        pr_err("%s: Internal clock never stabilised.\n",
                               mmc_hostname(host->mmc));
                        sdhci_dumpregs(host);
                        return;
                }
                udelay(10);
        }

        if (host->version >= SDHCI_SPEC_410 && host->v4_mode) {
                clk |= SDHCI_CLOCK_PLL_EN;
                clk &= ~SDHCI_CLOCK_INT_STABLE;
                sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

                /* Wait max 150 ms */
                timeout = ktime_add_ms(ktime_get(), 150);
                while (1) {
                        bool timedout = ktime_after(ktime_get(), timeout);

                        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                        if (clk & SDHCI_CLOCK_INT_STABLE)
                                break;
                        if (timedout) {
                                pr_err("%s: PLL clock never stabilised.\n",
                                       mmc_hostname(host->mmc));
                                sdhci_dumpregs(host);
                                return;
                        }
                        udelay(10);
                }
        }

        clk |= SDHCI_CLOCK_CARD_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
}
EXPORT_SYMBOL_GPL(sdhci_enable_clk);

void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
        u16 clk;

        host->mmc->actual_clock = 0;

        sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);

        if (clock == 0)
                return;

        clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);

        sdhci_enable_clk(host, clk);
}
EXPORT_SYMBOL_GPL(sdhci_set_clock);

static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
                                unsigned short vdd)
{
        struct mmc_host *mmc = host->mmc;

        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);

        if (mode != MMC_POWER_OFF)
                sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
        else
                sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
}

void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
                           unsigned short vdd)
{
        u8 pwr = 0;

        if (mode != MMC_POWER_OFF) {
                switch (1 << vdd) {
                case MMC_VDD_165_195:
                /*
                 * Without a regulator, SDHCI does not support 2.0v
                 * so we only get here if the driver deliberately
                 * added the 2.0v range to ocr_avail. Map it to 1.8v
                 * for the purpose of turning on the power.
                 */
                case MMC_VDD_20_21:
                        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:
                        WARN(1, "%s: Invalid vdd %#x\n",
                             mmc_hostname(host->mmc), vdd);
                        break;
                }
        }

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

        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);
        } else {
                /*
                 * 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);
        }
}
EXPORT_SYMBOL_GPL(sdhci_set_power_noreg);

void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
                     unsigned short vdd)
{
        if (IS_ERR(host->mmc->supply.vmmc))
                sdhci_set_power_noreg(host, mode, vdd);
        else
                sdhci_set_power_reg(host, mode, vdd);
}
EXPORT_SYMBOL_GPL(sdhci_set_power);

/*
 * Some controllers need to configure a valid bus voltage on their power
 * register regardless of whether an external regulator is taking care of power
 * supply. This helper function takes care of it if set as the controller's
 * sdhci_ops.set_power callback.
 */
void sdhci_set_power_and_bus_voltage(struct sdhci_host *host,
                                     unsigned char mode,
                                     unsigned short vdd)
{
        if (!IS_ERR(host->mmc->supply.vmmc)) {
                struct mmc_host *mmc = host->mmc;

                mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
        }
        sdhci_set_power_noreg(host, mode, vdd);
}
EXPORT_SYMBOL_GPL(sdhci_set_power_and_bus_voltage);

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

void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sdhci_host *host = mmc_priv(mmc);
        struct mmc_command *cmd;
        unsigned long flags;
        bool present;

        /* Firstly check card presence */
        present = mmc->ops->get_cd(mmc);

        spin_lock_irqsave(&host->lock, flags);

        sdhci_led_activate(host);

        if (sdhci_present_error(host, mrq->cmd, present))
                goto out_finish;

        cmd = sdhci_manual_cmd23(host, mrq) ? mrq->sbc : mrq->cmd;

        if (!sdhci_send_command_retry(host, cmd, flags))
                goto out_finish;

        spin_unlock_irqrestore(&host->lock, flags);

        return;

out_finish:
        sdhci_finish_mrq(host, mrq);
        spin_unlock_irqrestore(&host->lock, flags);
}
EXPORT_SYMBOL_GPL(sdhci_request);

int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sdhci_host *host = mmc_priv(mmc);
        struct mmc_command *cmd;
        unsigned long flags;
        int ret = 0;

        spin_lock_irqsave(&host->lock, flags);

        if (sdhci_present_error(host, mrq->cmd, true)) {
                sdhci_finish_mrq(host, mrq);
                goto out_finish;
        }

        cmd = sdhci_manual_cmd23(host, mrq) ? mrq->sbc : mrq->cmd;

        /*
         * The HSQ may send a command in interrupt context without polling
         * the busy signaling, which means we should return BUSY if controller
         * has not released inhibit bits to allow HSQ trying to send request
         * again in non-atomic context. So we should not finish this request
         * here.
         */
        if (!sdhci_send_command(host, cmd))
                ret = -EBUSY;
        else
                sdhci_led_activate(host);

out_finish:
        spin_unlock_irqrestore(&host->lock, flags);
        return ret;
}
EXPORT_SYMBOL_GPL(sdhci_request_atomic);

void sdhci_set_bus_width(struct sdhci_host *host, int width)
{
        u8 ctrl;

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
        if (width == MMC_BUS_WIDTH_8) {
                ctrl &= ~SDHCI_CTRL_4BITBUS;
                ctrl |= SDHCI_CTRL_8BITBUS;
        } else {
                if (host->mmc->caps & MMC_CAP_8_BIT_DATA)
                        ctrl &= ~SDHCI_CTRL_8BITBUS;
                if (width == MMC_BUS_WIDTH_4)
                        ctrl |= SDHCI_CTRL_4BITBUS;
                else
                        ctrl &= ~SDHCI_CTRL_4BITBUS;
        }
        sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}
EXPORT_SYMBOL_GPL(sdhci_set_bus_width);

void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing)
{
        u16 ctrl_2;

        ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
        /* Select Bus Speed Mode for host */
        ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
        if ((timing == MMC_TIMING_MMC_HS200) ||
            (timing == MMC_TIMING_UHS_SDR104))
                ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
        else if (timing == MMC_TIMING_UHS_SDR12)
                ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
        else if (timing == MMC_TIMING_UHS_SDR25)
                ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
        else if (timing == MMC_TIMING_UHS_SDR50)
                ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
        else if ((timing == MMC_TIMING_UHS_DDR50) ||
                 (timing == MMC_TIMING_MMC_DDR52))
                ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
        else if (timing == MMC_TIMING_MMC_HS400)
                ctrl_2 |= SDHCI_CTRL_HS400; /* Non-standard */
        sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}
EXPORT_SYMBOL_GPL(sdhci_set_uhs_signaling);

void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);
        u8 ctrl;

        if (ios->power_mode == MMC_POWER_UNDEFINED)
                return;

        if (host->flags & SDHCI_DEVICE_DEAD) {
                if (!IS_ERR(mmc->supply.vmmc) &&
                    ios->power_mode == MMC_POWER_OFF)
                        mmc_regulator_set_ocr(mmc, mmc->supply.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);

        if (!ios->clock || ios->clock != host->clock) {
                host->ops->set_clock(host, ios->clock);
                host->clock = ios->clock;

                if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK &&
                    host->clock) {
                        host->timeout_clk = host->mmc->actual_clock ?
                                                host->mmc->actual_clock / 1000 :
                                                host->clock / 1000;
                        host->mmc->max_busy_timeout =
                                host->ops->get_max_timeout_count ?
                                host->ops->get_max_timeout_count(host) :
                                1 << 27;
                        host->mmc->max_busy_timeout /= host->timeout_clk;
                }
        }

        if (host->ops->set_power)
                host->ops->set_power(host, ios->power_mode, ios->vdd);
        else
                sdhci_set_power(host, ios->power_mode, ios->vdd);

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

        host->ops->set_bus_width(host, ios->bus_width);

        ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);

        if (!(host->quirks & SDHCI_QUIRK_NO_HISPD_BIT)) {
                if (ios->timing == MMC_TIMING_SD_HS ||
                     ios->timing == MMC_TIMING_MMC_HS ||
                     ios->timing == MMC_TIMING_MMC_HS400 ||
                     ios->timing == MMC_TIMING_MMC_HS200 ||
                     ios->timing == MMC_TIMING_MMC_DDR52 ||
                     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;
                else
                        ctrl &= ~SDHCI_CTRL_HISPD;
        }

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

                if (!host->preset_enabled) {
                        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_readw(host, SDHCI_HOST_CONTROL2);
                        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_B)
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_B;
                        else if (ios->drv_type == MMC_SET_DRIVER_TYPE_C)
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_C;
                        else if (ios->drv_type == MMC_SET_DRIVER_TYPE_D)
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_D;
                        else {
                                pr_warn("%s: invalid driver type, default to driver type B\n",
                                        mmc_hostname(mmc));
                                ctrl_2 |= SDHCI_CTRL_DRV_TYPE_B;
                        }

                        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 */
                        host->ops->set_clock(host, host->clock);
                }

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

                host->ops->set_uhs_signaling(host, ios->timing);
                host->timing = ios->timing;

                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) ||
                                 (ios->timing == MMC_TIMING_MMC_DDR52))) {
                        u16 preset;

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

                /* Re-enable SD Clock */
                host->ops->set_clock(host, host->clock);
        } 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_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
}
EXPORT_SYMBOL_GPL(sdhci_set_ios);

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

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

        /* If nonremovable, assume that the card is always present. */
        if (!mmc_card_is_removable(host->mmc))
                return 1;

        /*
         * Try slot gpio detect, if defined it take precedence
         * over build in controller functionality
         */
        if (gpio_cd >= 0)
                return !!gpio_cd;

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

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

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 if (mmc_can_gpio_ro(host->mmc))
                is_readonly = mmc_gpio_get_ro(host->mmc);
        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_get_ro(struct mmc_host *mmc)
{
        struct sdhci_host *host = mmc_priv(mmc);
        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 void sdhci_enable_sdio_irq_nolock(struct sdhci_host *host, int enable)
{
        if (!(host->flags & SDHCI_DEVICE_DEAD)) {
                if (enable)
                        host->ier |= SDHCI_INT_CARD_INT;
                else
                        host->ier &= ~SDHCI_INT_CARD_INT;

                sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
                sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
        }
}

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

        if (enable)
                pm_runtime_get_noresume(host->mmc->parent);

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

        if (!enable)
                pm_runtime_put_noidle(host->mmc->parent);
}
EXPORT_SYMBOL_GPL(sdhci_enable_sdio_irq);

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

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

int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
                                      struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);
        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:
                if (!(host->flags & SDHCI_SIGNALING_330))
                        return -EINVAL;
                /* 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 (!IS_ERR(mmc->supply.vqmmc)) {
                        ret = mmc_regulator_set_vqmmc(mmc, ios);
                        if (ret < 0) {
                                pr_warn("%s: Switching to 3.3V signalling voltage failed\n",
                                        mmc_hostname(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_warn("%s: 3.3V regulator output did not become stable\n",
                        mmc_hostname(mmc));

                return -EAGAIN;
        case MMC_SIGNAL_VOLTAGE_180:
                if (!(host->flags & SDHCI_SIGNALING_180))
                        return -EINVAL;
                if (!IS_ERR(mmc->supply.vqmmc)) {
                        ret = mmc_regulator_set_vqmmc(mmc, ios);
                        if (ret < 0) {
                                pr_warn("%s: Switching to 1.8V signalling voltage failed\n",
                                        mmc_hostname(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);

                /* Some controller need to do more when switching */
                if (host->ops->voltage_switch)
                        host->ops->voltage_switch(host);

                /* 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_warn("%s: 1.8V regulator output did not become stable\n",
                        mmc_hostname(mmc));

                return -EAGAIN;
        case MMC_SIGNAL_VOLTAGE_120:
                if (!(host->flags & SDHCI_SIGNALING_120))
                        return -EINVAL;
                if (!IS_ERR(mmc->supply.vqmmc)) {
                        ret = mmc_regulator_set_vqmmc(mmc, ios);
                        if (ret < 0) {
                                pr_warn("%s: Switching to 1.2V signalling voltage failed\n",
                                        mmc_hostname(mmc));
                                return -EIO;
                        }
                }
                return 0;
        default:
                /* No signal voltage switch required */
                return 0;
        }
}
EXPORT_SYMBOL_GPL(sdhci_start_signal_voltage_switch);

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

        /* Check whether DAT[0] is 0 */
        present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);

        return !(present_state & SDHCI_DATA_0_LVL_MASK);
}

static int sdhci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct sdhci_host *host = mmc_priv(mmc);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);
        host->flags |= SDHCI_HS400_TUNING;
        spin_unlock_irqrestore(&host->lock, flags);

        return 0;
}

void sdhci_start_tuning(struct sdhci_host *host)
{
        u16 ctrl;

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
        ctrl |= SDHCI_CTRL_EXEC_TUNING;
        if (host->quirks2 & SDHCI_QUIRK2_TUNING_WORK_AROUND)
                ctrl |= SDHCI_CTRL_TUNED_CLK;
        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.
         */
        sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE);
        sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE);
}
EXPORT_SYMBOL_GPL(sdhci_start_tuning);

void sdhci_end_tuning(struct sdhci_host *host)
{
        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
}
EXPORT_SYMBOL_GPL(sdhci_end_tuning);

void sdhci_reset_tuning(struct sdhci_host *host)
{
        u16 ctrl;

        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
        ctrl &= ~SDHCI_CTRL_TUNED_CLK;
        ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
        sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
}
EXPORT_SYMBOL_GPL(sdhci_reset_tuning);

void sdhci_abort_tuning(struct sdhci_host *host, u32 opcode)
{
        sdhci_reset_tuning(host);

        sdhci_do_reset(host, SDHCI_RESET_CMD);
        sdhci_do_reset(host, SDHCI_RESET_DATA);

        sdhci_end_tuning(host);

        mmc_abort_tuning(host->mmc, opcode);
}
EXPORT_SYMBOL_GPL(sdhci_abort_tuning);

/*
 * We use sdhci_send_tuning() because mmc_send_tuning() is not a good fit. SDHCI
 * tuning command does not have a data payload (or rather the hardware does it
 * automatically) so mmc_send_tuning() will return -EIO. Also the tuning command
 * interrupt setup is different to other commands and there is no timeout
 * interrupt so special handling is needed.
 */
void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
{
        struct mmc_host *mmc = host->mmc;
        struct mmc_command cmd = {};
        struct mmc_request mrq = {};
        unsigned long flags;
        u32 b = host->sdma_boundary;

        spin_lock_irqsave(&host->lock, flags);

        cmd.opcode = opcode;
        cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
        cmd.mrq = &mrq;

        mrq.cmd = &cmd;
        /*
         * 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 &&
            mmc->ios.bus_width == MMC_BUS_WIDTH_8)
                sdhci_writew(host, SDHCI_MAKE_BLKSZ(b, 128), SDHCI_BLOCK_SIZE);
        else
                sdhci_writew(host, SDHCI_MAKE_BLKSZ(b, 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);

        if (!sdhci_send_command_retry(host, &cmd, flags)) {
                spin_unlock_irqrestore(&host->lock, flags);
                host->tuning_done = 0;
                return;
        }

        host->cmd = NULL;

        sdhci_del_timer(host, &mrq);

        host->tuning_done = 0;

        spin_unlock_irqrestore(&host->lock, flags);

        /* Wait for Buffer Read Ready interrupt */
        wait_event_timeout(host->buf_ready_int, (host->tuning_done == 1),
                           msecs_to_jiffies(50));

}
EXPORT_SYMBOL_GPL(sdhci_send_tuning);

static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
{
        int i;

        /*
         * Issue opcode repeatedly till Execute Tuning is set to 0 or the number
         * of loops reaches tuning loop count.
         */
        for (i = 0; i < host->tuning_loop_count; i++) {
                u16 ctrl;

                sdhci_send_tuning(host, opcode);

                if (!host->tuning_done) {
                        pr_debug("%s: Tuning timeout, falling back to fixed sampling clock\n",
                                 mmc_hostname(host->mmc));
                        sdhci_abort_tuning(host, opcode);
                        return -ETIMEDOUT;
                }

                /* Spec does not require a delay between tuning cycles */
                if (host->tuning_delay > 0)
                        mdelay(host->tuning_delay);

                ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
                if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) {
                        if (ctrl & SDHCI_CTRL_TUNED_CLK)
                                return 0; /* Success! */
                        break;
                }

        }

        pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",
                mmc_hostname(host->mmc));
        sdhci_reset_tuning(host);
        return -EAGAIN;
}

int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
        struct sdhci_host *host = mmc_priv(mmc);
        int err = 0;
        unsigned int tuning_count = 0;
        bool hs400_tuning;

        hs400_tuning = host->flags & SDHCI_HS400_TUNING;

        if (host->tuning_mode == SDHCI_TUNING_MODE_1)
                tuning_count = host->tuning_count;

        /*
         * The Host Controller needs tuning in case of SDR104 and DDR50
         * 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.
         */
        switch (host->timing) {
        /* HS400 tuning is done in HS200 mode */
        case MMC_TIMING_MMC_HS400:
                err = -EINVAL;
                goto out;

        case MMC_TIMING_MMC_HS200:
                /*
                 * Periodic re-tuning for HS400 is not expected to be needed, so
                 * disable it here.
                 */
                if (hs400_tuning)
                        tuning_count = 0;
                break;

        case MMC_TIMING_UHS_SDR104:
        case MMC_TIMING_UHS_DDR50:
                break;

        case MMC_TIMING_UHS_SDR50:
                if (host->flags & SDHCI_SDR50_NEEDS_TUNING)
                        break;
                fallthrough;

        default:
                goto out;
        }

        if (host->ops->platform_execute_tuning) {
                err = host->ops->platform_execute_tuning(host, opcode);
                goto out;
        }

        host->mmc->retune_period = tuning_count;

        if (host->tuning_delay < 0)
                host->tuning_delay = opcode == MMC_SEND_TUNING_BLOCK;

        sdhci_start_tuning(host);

        host->tuning_err = __sdhci_execute_tuning(host, opcode);

        sdhci_end_tuning(host);
out:
        host->flags &= ~SDHCI_HS400_TUNING;

        return err;
}
EXPORT_SYMBOL_GPL(sdhci_execute_tuning);

static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
{
        /* Host Controller v3.00 defines preset value registers */
        if (host->version < SDHCI_SPEC_300)
                return;

        /*
         * We only enable or disable Preset Value if they are not already
         * enabled or disabled respectively. Otherwise, we bail out.
         */
        if (host->preset_enabled != enable) {
                u16 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);

                if (enable)
                        ctrl |= SDHCI_CTRL_PRESET_VAL_ENABLE;
                else
                        ctrl &= ~SDHCI_CTRL_PRESET_VAL_ENABLE;

                sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);

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

                host->preset_enabled = enable;
        }
}

static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
                                int err)
{
        struct sdhci_host *host = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (data->host_cookie != COOKIE_UNMAPPED)
                dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
                             mmc_get_dma_dir(data));

        data->host_cookie = COOKIE_UNMAPPED;
}

static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct sdhci_host *host = mmc_priv(mmc);

        mrq->data->host_cookie = COOKIE_UNMAPPED;

        /*
         * No pre-mapping in the pre hook if we're using the bounce buffer,
         * for that we would need two bounce buffers since one buffer is
         * in flight when this is getting called.
         */
        if (host->flags & SDHCI_REQ_USE_DMA && !host->bounce_buffer)
                sdhci_pre_dma_transfer(host, mrq->data, COOKIE_PRE_MAPPED);
}

static void sdhci_error_out_mrqs(struct sdhci_host *host, int err)
{
        if (host->data_cmd) {
                host->data_cmd->error = err;
                sdhci_finish_mrq(host, host->data_cmd->mrq);
        }

        if (host->cmd) {
                host->cmd->error = err;
                sdhci_finish_mrq(host, host->cmd->mrq);
        }
}

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

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

        present = mmc->ops->get_cd(mmc);

        spin_lock_irqsave(&host->lock, flags);

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

                sdhci_do_reset(host, SDHCI_RESET_CMD);
                sdhci_do_reset(host, SDHCI_RESET_DATA);

                sdhci_error_out_mrqs(host, -ENOMEDIUM);
        }

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

static const struct mmc_host_ops sdhci_ops = {
        .request        = sdhci_request,
        .post_req       = sdhci_post_req,
        .pre_req        = sdhci_pre_req,
        .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,
        .ack_sdio_irq    = sdhci_ack_sdio_irq,
        .start_signal_voltage_switch    = sdhci_start_signal_voltage_switch,
        .prepare_hs400_tuning           = sdhci_prepare_hs400_tuning,
        .execute_tuning                 = sdhci_execute_tuning,
        .card_event                     = sdhci_card_event,
        .card_busy      = sdhci_card_busy,
};

/*****************************************************************************\
 *                                                                           *
 * Request done                                                              *
 *                                                                           *
\*****************************************************************************/

static bool sdhci_request_done(struct sdhci_host *host)
{
        unsigned long flags;
        struct mmc_request *mrq;
        int i;

        spin_lock_irqsave(&host->lock, flags);

        for (i = 0; i < SDHCI_MAX_MRQS; i++) {
                mrq = host->mrqs_done[i];
                if (mrq)
                        break;
        }

        if (!mrq) {
                spin_unlock_irqrestore(&host->lock, flags);
                return true;
        }

        /*