// SPDX-License-Identifier: GPL-2.0-only
/* linux/drivers/mmc/host/sdhci-s3c.c
 *
 * Copyright 2008 Openmoko Inc.
 * Copyright 2008 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * SDHCI (HSMMC) support for Samsung SoC
 */

#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/platform_data/mmc-sdhci-s3c.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>

#include <linux/mmc/host.h>

#include "sdhci.h"

#define MAX_BUS_CLK     (4)

#define S3C_SDHCI_CONTROL2                      (0x80)
#define S3C_SDHCI_CONTROL3                      (0x84)
#define S3C64XX_SDHCI_CONTROL4                  (0x8C)

#define S3C64XX_SDHCI_CTRL2_ENSTAASYNCCLR       BIT(31)
#define S3C64XX_SDHCI_CTRL2_ENCMDCNFMSK         BIT(30)
#define S3C_SDHCI_CTRL2_CDINVRXD3               BIT(29)
#define S3C_SDHCI_CTRL2_SLCARDOUT               BIT(28)

#define S3C_SDHCI_CTRL2_FLTCLKSEL_MASK          (0xf << 24)
#define S3C_SDHCI_CTRL2_FLTCLKSEL_SHIFT         (24)
#define S3C_SDHCI_CTRL2_FLTCLKSEL(_x)           ((_x) << 24)

#define S3C_SDHCI_CTRL2_LVLDAT_MASK             (0xff << 16)
#define S3C_SDHCI_CTRL2_LVLDAT_SHIFT            (16)
#define S3C_SDHCI_CTRL2_LVLDAT(_x)              ((_x) << 16)

#define S3C_SDHCI_CTRL2_ENFBCLKTX               BIT(15)
#define S3C_SDHCI_CTRL2_ENFBCLKRX               BIT(14)
#define S3C_SDHCI_CTRL2_SDCDSEL                 BIT(13)
#define S3C_SDHCI_CTRL2_SDSIGPC                 BIT(12)
#define S3C_SDHCI_CTRL2_ENBUSYCHKTXSTART        BIT(11)

#define S3C_SDHCI_CTRL2_DFCNT_MASK              (0x3 << 9)
#define S3C_SDHCI_CTRL2_DFCNT_SHIFT             (9)
#define S3C_SDHCI_CTRL2_DFCNT_NONE              (0x0 << 9)
#define S3C_SDHCI_CTRL2_DFCNT_4SDCLK            (0x1 << 9)
#define S3C_SDHCI_CTRL2_DFCNT_16SDCLK           (0x2 << 9)
#define S3C_SDHCI_CTRL2_DFCNT_64SDCLK           (0x3 << 9)

#define S3C_SDHCI_CTRL2_ENCLKOUTHOLD            BIT(8)
#define S3C_SDHCI_CTRL2_RWAITMODE               BIT(7)
#define S3C_SDHCI_CTRL2_DISBUFRD                BIT(6)

#define S3C_SDHCI_CTRL2_SELBASECLK_MASK         (0x3 << 4)
#define S3C_SDHCI_CTRL2_SELBASECLK_SHIFT        (4)
#define S3C_SDHCI_CTRL2_PWRSYNC                 BIT(3)
#define S3C_SDHCI_CTRL2_ENCLKOUTMSKCON          BIT(1)
#define S3C_SDHCI_CTRL2_HWINITFIN               BIT(0)

#define S3C_SDHCI_CTRL3_FCSEL3                  BIT(31)
#define S3C_SDHCI_CTRL3_FCSEL2                  BIT(23)
#define S3C_SDHCI_CTRL3_FCSEL1                  BIT(15)
#define S3C_SDHCI_CTRL3_FCSEL0                  BIT(7)

#define S3C_SDHCI_CTRL3_FIA3_MASK               (0x7f << 24)
#define S3C_SDHCI_CTRL3_FIA3_SHIFT              (24)
#define S3C_SDHCI_CTRL3_FIA3(_x)                ((_x) << 24)

#define S3C_SDHCI_CTRL3_FIA2_MASK               (0x7f << 16)
#define S3C_SDHCI_CTRL3_FIA2_SHIFT              (16)
#define S3C_SDHCI_CTRL3_FIA2(_x)                ((_x) << 16)

#define S3C_SDHCI_CTRL3_FIA1_MASK               (0x7f << 8)
#define S3C_SDHCI_CTRL3_FIA1_SHIFT              (8)
#define S3C_SDHCI_CTRL3_FIA1(_x)                ((_x) << 8)

#define S3C_SDHCI_CTRL3_FIA0_MASK               (0x7f << 0)
#define S3C_SDHCI_CTRL3_FIA0_SHIFT              (0)
#define S3C_SDHCI_CTRL3_FIA0(_x)                ((_x) << 0)

#define S3C64XX_SDHCI_CONTROL4_DRIVE_MASK       (0x3 << 16)
#define S3C64XX_SDHCI_CONTROL4_DRIVE_SHIFT      (16)
#define S3C64XX_SDHCI_CONTROL4_DRIVE_2mA        (0x0 << 16)
#define S3C64XX_SDHCI_CONTROL4_DRIVE_4mA        (0x1 << 16)
#define S3C64XX_SDHCI_CONTROL4_DRIVE_7mA        (0x2 << 16)
#define S3C64XX_SDHCI_CONTROL4_DRIVE_9mA        (0x3 << 16)

#define S3C64XX_SDHCI_CONTROL4_BUSY             (1)

/**
 * struct sdhci_s3c - S3C SDHCI instance
 * @host: The SDHCI host created
 * @pdev: The platform device we where created from.
 * @ioarea: The resource created when we claimed the IO area.
 * @pdata: The platform data for this controller.
 * @cur_clk: The index of the current bus clock.
 * @clk_io: The clock for the internal bus interface.
 * @clk_bus: The clocks that are available for the SD/MMC bus clock.
 */
struct sdhci_s3c {
        struct sdhci_host       *host;
        struct platform_device  *pdev;
        struct resource         *ioarea;
        struct s3c_sdhci_platdata *pdata;
        int                     cur_clk;
        int                     ext_cd_irq;
        int                     ext_cd_gpio;

        struct clk              *clk_io;
        struct clk              *clk_bus[MAX_BUS_CLK];
        unsigned long           clk_rates[MAX_BUS_CLK];

        bool                    no_divider;
};

/**
 * struct sdhci_s3c_driver_data - S3C SDHCI platform specific driver data
 * @sdhci_quirks: sdhci host specific quirks.
 *
 * Specifies platform specific configuration of sdhci controller.
 * Note: A structure for driver specific platform data is used for future
 * expansion of its usage.
 */
struct sdhci_s3c_drv_data {
        unsigned int    sdhci_quirks;
        bool            no_divider;
};

static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
{
        return sdhci_priv(host);
}

/**
 * sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
 * @host: The SDHCI host instance.
 *
 * Callback to return the maximum clock rate acheivable by the controller.
*/
static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        unsigned long rate, max = 0;
        int src;

        for (src = 0; src < MAX_BUS_CLK; src++) {
                rate = ourhost->clk_rates[src];
                if (rate > max)
                        max = rate;
        }

        return max;
}

/**
 * sdhci_s3c_consider_clock - consider one the bus clocks for current setting
 * @ourhost: Our SDHCI instance.
 * @src: The source clock index.
 * @wanted: The clock frequency wanted.
 */
static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
                                             unsigned int src,
                                             unsigned int wanted)
{
        unsigned long rate;
        struct clk *clksrc = ourhost->clk_bus[src];
        int shift;

        if (IS_ERR(clksrc))
                return UINT_MAX;

        /*
         * If controller uses a non-standard clock division, find the best clock
         * speed possible with selected clock source and skip the division.
         */
        if (ourhost->no_divider) {
                rate = clk_round_rate(clksrc, wanted);
                return wanted - rate;
        }

        rate = ourhost->clk_rates[src];

        for (shift = 0; shift <= 8; ++shift) {
                if ((rate >> shift) <= wanted)
                        break;
        }

        if (shift > 8) {
                dev_dbg(&ourhost->pdev->dev,
                        "clk %d: rate %ld, min rate %lu > wanted %u\n",
                        src, rate, rate / 256, wanted);
                return UINT_MAX;
        }

        dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
                src, rate, wanted, rate >> shift);

        return wanted - (rate >> shift);
}

/**
 * sdhci_s3c_set_clock - callback on clock change
 * @host: The SDHCI host being changed
 * @clock: The clock rate being requested.
 *
 * When the card's clock is going to be changed, look at the new frequency
 * and find the best clock source to go with it.
*/
static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        unsigned int best = UINT_MAX;
        unsigned int delta;
        int best_src = 0;
        int src;
        u32 ctrl;

        host->mmc->actual_clock = 0;

        /* don't bother if the clock is going off. */
        if (clock == 0) {
                sdhci_set_clock(host, clock);
                return;
        }

        for (src = 0; src < MAX_BUS_CLK; src++) {
                delta = sdhci_s3c_consider_clock(ourhost, src, clock);
                if (delta < best) {
                        best = delta;
                        best_src = src;
                }
        }

        dev_dbg(&ourhost->pdev->dev,
                "selected source %d, clock %d, delta %d\n",
                 best_src, clock, best);

        /* select the new clock source */
        if (ourhost->cur_clk != best_src) {
                struct clk *clk = ourhost->clk_bus[best_src];

                clk_prepare_enable(clk);
                if (ourhost->cur_clk >= 0)
                        clk_disable_unprepare(
                                        ourhost->clk_bus[ourhost->cur_clk]);

                ourhost->cur_clk = best_src;
                host->max_clk = ourhost->clk_rates[best_src];
        }

        /* turn clock off to card before changing clock source */
        writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);

        ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
        ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
        ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
        writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);

        /* reprogram default hardware configuration */
        writel(S3C64XX_SDHCI_CONTROL4_DRIVE_9mA,
                host->ioaddr + S3C64XX_SDHCI_CONTROL4);

        ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
        ctrl |= (S3C64XX_SDHCI_CTRL2_ENSTAASYNCCLR |
                  S3C64XX_SDHCI_CTRL2_ENCMDCNFMSK |
                  S3C_SDHCI_CTRL2_ENFBCLKRX |
                  S3C_SDHCI_CTRL2_DFCNT_NONE |
                  S3C_SDHCI_CTRL2_ENCLKOUTHOLD);
        writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);

        /* reconfigure the controller for new clock rate */
        ctrl = (S3C_SDHCI_CTRL3_FCSEL1 | S3C_SDHCI_CTRL3_FCSEL0);
        if (clock < 25 * 1000000)
                ctrl |= (S3C_SDHCI_CTRL3_FCSEL3 | S3C_SDHCI_CTRL3_FCSEL2);
        writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL3);

        sdhci_set_clock(host, clock);
}

/**
 * sdhci_s3c_get_min_clock - callback to get minimal supported clock value
 * @host: The SDHCI host being queried
 *
 * To init mmc host properly a minimal clock value is needed. For high system
 * bus clock's values the standard formula gives values out of allowed range.
 * The clock still can be set to lower values, if clock source other then
 * system bus is selected.
*/
static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        unsigned long rate, min = ULONG_MAX;
        int src;

        for (src = 0; src < MAX_BUS_CLK; src++) {
                rate = ourhost->clk_rates[src] / 256;
                if (!rate)
                        continue;
                if (rate < min)
                        min = rate;
        }

        return min;
}

/* sdhci_cmu_get_max_clk - callback to get maximum clock frequency.*/
static unsigned int sdhci_cmu_get_max_clock(struct sdhci_host *host)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        unsigned long rate, max = 0;
        int src;

        for (src = 0; src < MAX_BUS_CLK; src++) {
                struct clk *clk;

                clk = ourhost->clk_bus[src];
                if (IS_ERR(clk))
                        continue;

                rate = clk_round_rate(clk, ULONG_MAX);
                if (rate > max)
                        max = rate;
        }

        return max;
}

/* sdhci_cmu_get_min_clock - callback to get minimal supported clock value. */
static unsigned int sdhci_cmu_get_min_clock(struct sdhci_host *host)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        unsigned long rate, min = ULONG_MAX;
        int src;

        for (src = 0; src < MAX_BUS_CLK; src++) {
                struct clk *clk;

                clk = ourhost->clk_bus[src];
                if (IS_ERR(clk))
                        continue;

                rate = clk_round_rate(clk, 0);
                if (rate < min)
                        min = rate;
        }

        return min;
}

/* sdhci_cmu_set_clock - callback on clock change.*/
static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
{
        struct sdhci_s3c *ourhost = to_s3c(host);
        struct device *dev = &ourhost->pdev->dev;
        unsigned long timeout;
        u16 clk = 0;
        int ret;

        host->mmc->actual_clock = 0;

        /* If the clock is going off, set to 0 at clock control register */
        if (clock == 0) {
                sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
                return;
        }

        sdhci_s3c_set_clock(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);

        ret = clk_set_rate(ourhost->clk_bus[ourhost->cur_clk], clock);
        if (ret != 0) {
                dev_err(dev, "%s: failed to set clock rate %uHz\n",
                        mmc_hostname(host->mmc), clock);
                return;
        }

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

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

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

static struct sdhci_ops sdhci_s3c_ops = {
        .get_max_clock          = sdhci_s3c_get_max_clk,
        .set_clock              = sdhci_s3c_set_clock,
        .get_min_clock          = sdhci_s3c_get_min_clock,
        .set_bus_width          = sdhci_set_bus_width,
        .reset                  = sdhci_reset,
        .set_uhs_signaling      = sdhci_set_uhs_signaling,
};

#ifdef CONFIG_OF
static int sdhci_s3c_parse_dt(struct device *dev,
                struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
{
        struct device_node *node = dev->of_node;
        u32 max_width;

        /* if the bus-width property is not specified, assume width as 1 */
        if (of_property_read_u32(node, "bus-width", &max_width))
                max_width = 1;
        pdata->max_width = max_width;

        /* get the card detection method */
        if (of_get_property(node, "broken-cd", NULL)) {
                pdata->cd_type = S3C_SDHCI_CD_NONE;
                return 0;
        }

        if (of_get_property(node, "non-removable", NULL)) {
                pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
                return 0;
        }

        if (of_get_named_gpio(node, "cd-gpios", 0))
                return 0;

        /* assuming internal card detect that will be configured by pinctrl */
        pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
        return 0;
}
#else
static int sdhci_s3c_parse_dt(struct device *dev,
                struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
{
        return -EINVAL;
}
#endif

static const struct of_device_id sdhci_s3c_dt_match[];

static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
                        struct platform_device *pdev)
{
#ifdef CONFIG_OF
        if (pdev->dev.of_node) {
                const struct of_device_id *match;
                match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
                return (struct sdhci_s3c_drv_data *)match->data;
        }
#endif
        return (struct sdhci_s3c_drv_data *)
                        platform_get_device_id(pdev)->driver_data;
}

static int sdhci_s3c_probe(struct platform_device *pdev)
{
        struct s3c_sdhci_platdata *pdata;
        struct sdhci_s3c_drv_data *drv_data;
        struct device *dev = &pdev->dev;
        struct sdhci_host *host;
        struct sdhci_s3c *sc;
        struct resource *res;
        int ret, irq, ptr, clks;

        if (!pdev->dev.platform_data && !pdev->dev.of_node) {
                dev_err(dev, "no device data specified\n");
                return -ENOENT;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
        if (IS_ERR(host)) {
                dev_err(dev, "sdhci_alloc_host() failed\n");
                return PTR_ERR(host);
        }
        sc = sdhci_priv(host);

        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
                ret = -ENOMEM;
                goto err_pdata_io_clk;
        }

        if (pdev->dev.of_node) {
                ret = sdhci_s3c_parse_dt(&pdev->dev, host, pdata);
                if (ret)
                        goto err_pdata_io_clk;
        } else {
                memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
                sc->ext_cd_gpio = -1; /* invalid gpio number */
        }

        drv_data = sdhci_s3c_get_driver_data(pdev);

        sc->host = host;
        sc->pdev = pdev;
        sc->pdata = pdata;
        sc->cur_clk = -1;

        platform_set_drvdata(pdev, host);

        sc->clk_io = devm_clk_get(dev, "hsmmc");
        if (IS_ERR(sc->clk_io)) {
                dev_err(dev, "failed to get io clock\n");
                ret = PTR_ERR(sc->clk_io);
                goto err_pdata_io_clk;
        }

        /* enable the local io clock and keep it running for the moment. */
        clk_prepare_enable(sc->clk_io);

        for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
                char name[14];

                snprintf(name, 14, "mmc_busclk.%d", ptr);
                sc->clk_bus[ptr] = devm_clk_get(dev, name);
                if (IS_ERR(sc->clk_bus[ptr]))
                        continue;

                clks++;
                sc->clk_rates[ptr] = clk_get_rate(sc->clk_bus[ptr]);

                dev_info(dev, "clock source %d: %s (%ld Hz)\n",
                                ptr, name, sc->clk_rates[ptr]);
        }

        if (clks == 0) {
                dev_err(dev, "failed to find any bus clocks\n");
                ret = -ENOENT;
                goto err_no_busclks;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        host->ioaddr = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(host->ioaddr)) {
                ret = PTR_ERR(host->ioaddr);
                goto err_req_regs;
        }

        /* Ensure we have minimal gpio selected CMD/CLK/Detect */
        if (pdata->cfg_gpio)
                pdata->cfg_gpio(pdev, pdata->max_width);

        host->hw_name = "samsung-hsmmc";
        host->ops = &sdhci_s3c_ops;
        host->quirks = 0;
        host->quirks2 = 0;
        host->irq = irq;

        /* Setup quirks for the controller */
        host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
        host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
        if (drv_data) {
                host->quirks |= drv_data->sdhci_quirks;
                sc->no_divider = drv_data->no_divider;
        }

#ifndef CONFIG_MMC_SDHCI_S3C_DMA

        /* we currently see overruns on errors, so disable the SDMA
         * support as well. */
        host->quirks |= SDHCI_QUIRK_BROKEN_DMA;

#endif /* CONFIG_MMC_SDHCI_S3C_DMA */

        /* It seems we do not get an DATA transfer complete on non-busy
         * transfers, not sure if this is a problem with this specific
         * SDHCI block, or a missing configuration that needs to be set. */
        host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;

        /* This host supports the Auto CMD12 */
        host->quirks |= SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12;

        /* Samsung SoCs need BROKEN_ADMA_ZEROLEN_DESC */
        host->quirks |= SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC;

        if (pdata->cd_type == S3C_SDHCI_CD_NONE ||
            pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
                host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;

        if (pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
                host->mmc->caps = MMC_CAP_NONREMOVABLE;

        switch (pdata->max_width) {
        case 8:
                host->mmc->caps |= MMC_CAP_8_BIT_DATA;
                /* Fall through */
        case 4:
                host->mmc->caps |= MMC_CAP_4_BIT_DATA;
                break;
        }

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

        host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
                         SDHCI_QUIRK_32BIT_DMA_SIZE);

        /* HSMMC on Samsung SoCs uses SDCLK as timeout clock */
        host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;

        /*
         * If controller does not have internal clock divider,
         * we can use overriding functions instead of default.
         */
        if (sc->no_divider) {
                sdhci_s3c_ops.set_clock = sdhci_cmu_set_clock;
                sdhci_s3c_ops.get_min_clock = sdhci_cmu_get_min_clock;
                sdhci_s3c_ops.get_max_clock = sdhci_cmu_get_max_clock;
        }

        /* It supports additional host capabilities if needed */
        if (pdata->host_caps)
                host->mmc->caps |= pdata->host_caps;

        if (pdata->host_caps2)
                host->mmc->caps2 |= pdata->host_caps2;

        pm_runtime_enable(&pdev->dev);
        pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
        pm_runtime_use_autosuspend(&pdev->dev);
        pm_suspend_ignore_children(&pdev->dev, 1);

        ret = mmc_of_parse(host->mmc);
        if (ret)
                goto err_req_regs;

        ret = sdhci_add_host(host);
        if (ret)
                goto err_req_regs;

#ifdef CONFIG_PM
        if (pdata->cd_type != S3C_SDHCI_CD_INTERNAL)
                clk_disable_unprepare(sc->clk_io);
#endif
        return 0;

 err_req_regs:
        pm_runtime_disable(&pdev->dev);

 err_no_busclks:
        clk_disable_unprepare(sc->clk_io);

 err_pdata_io_clk:
        sdhci_free_host(host);

        return ret;
}

static int sdhci_s3c_remove(struct platform_device *pdev)
{
        struct sdhci_host *host =  platform_get_drvdata(pdev);
        struct sdhci_s3c *sc = sdhci_priv(host);

        if (sc->ext_cd_irq)
                free_irq(sc->ext_cd_irq, sc);

#ifdef CONFIG_PM
        if (sc->pdata->cd_type != S3C_SDHCI_CD_INTERNAL)
                clk_prepare_enable(sc->clk_io);
#endif
        sdhci_remove_host(host, 1);

        pm_runtime_dont_use_autosuspend(&pdev->dev);
        pm_runtime_disable(&pdev->dev);

        clk_disable_unprepare(sc->clk_io);

        sdhci_free_host(host);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int sdhci_s3c_suspend(struct device *dev)
{
        struct sdhci_host *host = dev_get_drvdata(dev);

        if (host->tuning_mode != SDHCI_TUNING_MODE_3)
                mmc_retune_needed(host->mmc);

        return sdhci_suspend_host(host);
}

static int sdhci_s3c_resume(struct device *dev)
{
        struct sdhci_host *host = dev_get_drvdata(dev);

        return sdhci_resume_host(host);
}
#endif

#ifdef CONFIG_PM
static int sdhci_s3c_runtime_suspend(struct device *dev)
{
        struct sdhci_host *host = dev_get_drvdata(dev);
        struct sdhci_s3c *ourhost = to_s3c(host);
        struct clk *busclk = ourhost->clk_io;
        int ret;

        ret = sdhci_runtime_suspend_host(host);

        if (host->tuning_mode != SDHCI_TUNING_MODE_3)
                mmc_retune_needed(host->mmc);

        if (ourhost->cur_clk >= 0)
                clk_disable_unprepare(ourhost->clk_bus[ourhost->cur_clk]);
        clk_disable_unprepare(busclk);
        return ret;
}

static int sdhci_s3c_runtime_resume(struct device *dev)
{
        struct sdhci_host *host = dev_get_drvdata(dev);
        struct sdhci_s3c *ourhost = to_s3c(host);
        struct clk *busclk = ourhost->clk_io;
        int ret;

        clk_prepare_enable(busclk);
        if (ourhost->cur_clk >= 0)
                clk_prepare_enable(ourhost->clk_bus[ourhost->cur_clk]);
        ret = sdhci_runtime_resume_host(host, 0);
        return ret;
}
#endif

static const struct dev_pm_ops sdhci_s3c_pmops = {
        SET_SYSTEM_SLEEP_PM_OPS(sdhci_s3c_suspend, sdhci_s3c_resume)
        SET_RUNTIME_PM_OPS(sdhci_s3c_runtime_suspend, sdhci_s3c_runtime_resume,
                           NULL)
};

static const struct platform_device_id sdhci_s3c_driver_ids[] = {
        {
                .name           = "s3c-sdhci",
                .driver_data    = (kernel_ulong_t)NULL,
        },
        { }
};
MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);

#ifdef CONFIG_OF
static struct sdhci_s3c_drv_data exynos4_sdhci_drv_data = {
        .no_divider = true,
};

static const struct of_device_id sdhci_s3c_dt_match[] = {
        { .compatible = "samsung,s3c6410-sdhci", },
        { .compatible = "samsung,exynos4210-sdhci",
                .data = &exynos4_sdhci_drv_data },
        {},
};
MODULE_DEVICE_TABLE(of, sdhci_s3c_dt_match);
#endif

static struct platform_driver sdhci_s3c_driver = {
        .probe          = sdhci_s3c_probe,
        .remove         = sdhci_s3c_remove,
        .id_table       = sdhci_s3c_driver_ids,
        .driver         = {
                .name   = "s3c-sdhci",
                .of_match_table = of_match_ptr(sdhci_s3c_dt_match),
                .pm     = &sdhci_s3c_pmops,
        },
};

module_platform_driver(sdhci_s3c_driver);

MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:s3c-sdhci");