// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/mmc/s3cmci.h - Samsung S3C MCI driver
 *
 *  Copyright (C) 2004-2006 maintech GmbH, Thomas Kleffel <tk@maintech.de>
 *
 * Current driver maintained by Ben Dooks and Simtec Electronics
 *  Copyright (C) 2008 Simtec Electronics <ben-linux@fluff.org>
 */

#include <linux/module.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/mmc/host.h>
#include <linux/platform_device.h>
#include <linux/cpufreq.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/mmc/slot-gpio.h>

#include <plat/gpio-cfg.h>
#include <mach/dma.h>
#include <mach/gpio-samsung.h>

#include <linux/platform_data/mmc-s3cmci.h>

#include "s3cmci.h"

#define DRIVER_NAME "s3c-mci"

#define S3C2410_SDICON                  (0x00)
#define S3C2410_SDIPRE                  (0x04)
#define S3C2410_SDICMDARG               (0x08)
#define S3C2410_SDICMDCON               (0x0C)
#define S3C2410_SDICMDSTAT              (0x10)
#define S3C2410_SDIRSP0                 (0x14)
#define S3C2410_SDIRSP1                 (0x18)
#define S3C2410_SDIRSP2                 (0x1C)
#define S3C2410_SDIRSP3                 (0x20)
#define S3C2410_SDITIMER                (0x24)
#define S3C2410_SDIBSIZE                (0x28)
#define S3C2410_SDIDCON                 (0x2C)
#define S3C2410_SDIDCNT                 (0x30)
#define S3C2410_SDIDSTA                 (0x34)
#define S3C2410_SDIFSTA                 (0x38)

#define S3C2410_SDIDATA                 (0x3C)
#define S3C2410_SDIIMSK                 (0x40)

#define S3C2440_SDIDATA                 (0x40)
#define S3C2440_SDIIMSK                 (0x3C)

#define S3C2440_SDICON_SDRESET          (1 << 8)
#define S3C2410_SDICON_SDIOIRQ          (1 << 3)
#define S3C2410_SDICON_FIFORESET        (1 << 1)
#define S3C2410_SDICON_CLOCKTYPE        (1 << 0)

#define S3C2410_SDICMDCON_LONGRSP       (1 << 10)
#define S3C2410_SDICMDCON_WAITRSP       (1 << 9)
#define S3C2410_SDICMDCON_CMDSTART      (1 << 8)
#define S3C2410_SDICMDCON_SENDERHOST    (1 << 6)
#define S3C2410_SDICMDCON_INDEX         (0x3f)

#define S3C2410_SDICMDSTAT_CRCFAIL      (1 << 12)
#define S3C2410_SDICMDSTAT_CMDSENT      (1 << 11)
#define S3C2410_SDICMDSTAT_CMDTIMEOUT   (1 << 10)
#define S3C2410_SDICMDSTAT_RSPFIN       (1 << 9)

#define S3C2440_SDIDCON_DS_WORD         (2 << 22)
#define S3C2410_SDIDCON_TXAFTERRESP     (1 << 20)
#define S3C2410_SDIDCON_RXAFTERCMD      (1 << 19)
#define S3C2410_SDIDCON_BLOCKMODE       (1 << 17)
#define S3C2410_SDIDCON_WIDEBUS         (1 << 16)
#define S3C2410_SDIDCON_DMAEN           (1 << 15)
#define S3C2410_SDIDCON_STOP            (1 << 14)
#define S3C2440_SDIDCON_DATSTART        (1 << 14)

#define S3C2410_SDIDCON_XFER_RXSTART    (2 << 12)
#define S3C2410_SDIDCON_XFER_TXSTART    (3 << 12)

#define S3C2410_SDIDCON_BLKNUM_MASK     (0xFFF)

#define S3C2410_SDIDSTA_SDIOIRQDETECT   (1 << 9)
#define S3C2410_SDIDSTA_FIFOFAIL        (1 << 8)
#define S3C2410_SDIDSTA_CRCFAIL         (1 << 7)
#define S3C2410_SDIDSTA_RXCRCFAIL       (1 << 6)
#define S3C2410_SDIDSTA_DATATIMEOUT     (1 << 5)
#define S3C2410_SDIDSTA_XFERFINISH      (1 << 4)
#define S3C2410_SDIDSTA_TXDATAON        (1 << 1)
#define S3C2410_SDIDSTA_RXDATAON        (1 << 0)

#define S3C2440_SDIFSTA_FIFORESET       (1 << 16)
#define S3C2440_SDIFSTA_FIFOFAIL        (3 << 14)
#define S3C2410_SDIFSTA_TFDET           (1 << 13)
#define S3C2410_SDIFSTA_RFDET           (1 << 12)
#define S3C2410_SDIFSTA_COUNTMASK       (0x7f)

#define S3C2410_SDIIMSK_RESPONSECRC     (1 << 17)
#define S3C2410_SDIIMSK_CMDSENT         (1 << 16)
#define S3C2410_SDIIMSK_CMDTIMEOUT      (1 << 15)
#define S3C2410_SDIIMSK_RESPONSEND      (1 << 14)
#define S3C2410_SDIIMSK_SDIOIRQ         (1 << 12)
#define S3C2410_SDIIMSK_FIFOFAIL        (1 << 11)
#define S3C2410_SDIIMSK_CRCSTATUS       (1 << 10)
#define S3C2410_SDIIMSK_DATACRC         (1 << 9)
#define S3C2410_SDIIMSK_DATATIMEOUT     (1 << 8)
#define S3C2410_SDIIMSK_DATAFINISH      (1 << 7)
#define S3C2410_SDIIMSK_TXFIFOHALF      (1 << 4)
#define S3C2410_SDIIMSK_RXFIFOLAST      (1 << 2)
#define S3C2410_SDIIMSK_RXFIFOHALF      (1 << 0)

enum dbg_channels {
        dbg_err   = (1 << 0),
        dbg_debug = (1 << 1),
        dbg_info  = (1 << 2),
        dbg_irq   = (1 << 3),
        dbg_sg    = (1 << 4),
        dbg_dma   = (1 << 5),
        dbg_pio   = (1 << 6),
        dbg_fail  = (1 << 7),
        dbg_conf  = (1 << 8),
};

static const int dbgmap_err   = dbg_fail;
static const int dbgmap_info  = dbg_info | dbg_conf;
static const int dbgmap_debug = dbg_err | dbg_debug;

#define dbg(host, channels, args...)              \
        do {                                      \
        if (dbgmap_err & channels)                \
                dev_err(&host->pdev->dev, args);  \
        else if (dbgmap_info & channels)          \
                dev_info(&host->pdev->dev, args); \
        else if (dbgmap_debug & channels)         \
                dev_dbg(&host->pdev->dev, args);  \
        } while (0)

static void finalize_request(struct s3cmci_host *host);
static void s3cmci_send_request(struct mmc_host *mmc);
static void s3cmci_reset(struct s3cmci_host *host);

#ifdef CONFIG_MMC_DEBUG

static void dbg_dumpregs(struct s3cmci_host *host, char *prefix)
{
        u32 con, pre, cmdarg, cmdcon, cmdsta, r0, r1, r2, r3, timer, bsize;
        u32 datcon, datcnt, datsta, fsta, imask;

        con     = readl(host->base + S3C2410_SDICON);
        pre     = readl(host->base + S3C2410_SDIPRE);
        cmdarg  = readl(host->base + S3C2410_SDICMDARG);
        cmdcon  = readl(host->base + S3C2410_SDICMDCON);
        cmdsta  = readl(host->base + S3C2410_SDICMDSTAT);
        r0      = readl(host->base + S3C2410_SDIRSP0);
        r1      = readl(host->base + S3C2410_SDIRSP1);
        r2      = readl(host->base + S3C2410_SDIRSP2);
        r3      = readl(host->base + S3C2410_SDIRSP3);
        timer   = readl(host->base + S3C2410_SDITIMER);
        bsize   = readl(host->base + S3C2410_SDIBSIZE);
        datcon  = readl(host->base + S3C2410_SDIDCON);
        datcnt  = readl(host->base + S3C2410_SDIDCNT);
        datsta  = readl(host->base + S3C2410_SDIDSTA);
        fsta    = readl(host->base + S3C2410_SDIFSTA);
        imask   = readl(host->base + host->sdiimsk);

        dbg(host, dbg_debug, "%s  CON:[%08x]  PRE:[%08x]  TMR:[%08x]\n",
                                prefix, con, pre, timer);

        dbg(host, dbg_debug, "%s CCON:[%08x] CARG:[%08x] CSTA:[%08x]\n",
                                prefix, cmdcon, cmdarg, cmdsta);

        dbg(host, dbg_debug, "%s DCON:[%08x] FSTA:[%08x]"
                               " DSTA:[%08x] DCNT:[%08x]\n",
                                prefix, datcon, fsta, datsta, datcnt);

        dbg(host, dbg_debug, "%s   R0:[%08x]   R1:[%08x]"
                               "   R2:[%08x]   R3:[%08x]\n",
                                prefix, r0, r1, r2, r3);
}

static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
                           int stop)
{
        snprintf(host->dbgmsg_cmd, 300,
                 "#%u%s op:%i arg:0x%08x flags:0x08%x retries:%u",
                 host->ccnt, (stop ? " (STOP)" : ""),
                 cmd->opcode, cmd->arg, cmd->flags, cmd->retries);

        if (cmd->data) {
                snprintf(host->dbgmsg_dat, 300,
                         "#%u bsize:%u blocks:%u bytes:%u",
                         host->dcnt, cmd->data->blksz,
                         cmd->data->blocks,
                         cmd->data->blocks * cmd->data->blksz);
        } else {
                host->dbgmsg_dat[0] = '\0';
        }
}

static void dbg_dumpcmd(struct s3cmci_host *host, struct mmc_command *cmd,
                        int fail)
{
        unsigned int dbglvl = fail ? dbg_fail : dbg_debug;

        if (!cmd)
                return;

        if (cmd->error == 0) {
                dbg(host, dbglvl, "CMD[OK] %s R0:0x%08x\n",
                        host->dbgmsg_cmd, cmd->resp[0]);
        } else {
                dbg(host, dbglvl, "CMD[ERR %i] %s Status:%s\n",
                        cmd->error, host->dbgmsg_cmd, host->status);
        }

        if (!cmd->data)
                return;

        if (cmd->data->error == 0) {
                dbg(host, dbglvl, "DAT[OK] %s\n", host->dbgmsg_dat);
        } else {
                dbg(host, dbglvl, "DAT[ERR %i] %s DCNT:0x%08x\n",
                        cmd->data->error, host->dbgmsg_dat,
                        readl(host->base + S3C2410_SDIDCNT));
        }
}
#else
static void dbg_dumpcmd(struct s3cmci_host *host,
                        struct mmc_command *cmd, int fail) { }

static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
                           int stop) { }

static void dbg_dumpregs(struct s3cmci_host *host, char *prefix) { }

#endif /* CONFIG_MMC_DEBUG */

/**
 * s3cmci_host_usedma - return whether the host is using dma or pio
 * @host: The host state
 *
 * Return true if the host is using DMA to transfer data, else false
 * to use PIO mode. Will return static data depending on the driver
 * configuration.
 */
static inline bool s3cmci_host_usedma(struct s3cmci_host *host)
{
#ifdef CONFIG_MMC_S3C_PIO
        return false;
#else /* CONFIG_MMC_S3C_DMA */
        return true;
#endif
}

static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
{
        u32 newmask;

        newmask = readl(host->base + host->sdiimsk);
        newmask |= imask;

        writel(newmask, host->base + host->sdiimsk);

        return newmask;
}

static inline u32 disable_imask(struct s3cmci_host *host, u32 imask)
{
        u32 newmask;

        newmask = readl(host->base + host->sdiimsk);
        newmask &= ~imask;

        writel(newmask, host->base + host->sdiimsk);

        return newmask;
}

static inline void clear_imask(struct s3cmci_host *host)
{
        u32 mask = readl(host->base + host->sdiimsk);

        /* preserve the SDIO IRQ mask state */
        mask &= S3C2410_SDIIMSK_SDIOIRQ;
        writel(mask, host->base + host->sdiimsk);
}

/**
 * s3cmci_check_sdio_irq - test whether the SDIO IRQ is being signalled
 * @host: The host to check.
 *
 * Test to see if the SDIO interrupt is being signalled in case the
 * controller has failed to re-detect a card interrupt. Read GPE8 and
 * see if it is low and if so, signal a SDIO interrupt.
 *
 * This is currently called if a request is finished (we assume that the
 * bus is now idle) and when the SDIO IRQ is enabled in case the IRQ is
 * already being indicated.
*/
static void s3cmci_check_sdio_irq(struct s3cmci_host *host)
{
        if (host->sdio_irqen) {
                if (gpio_get_value(S3C2410_GPE(8)) == 0) {
                        pr_debug("%s: signalling irq\n", __func__);
                        mmc_signal_sdio_irq(host->mmc);
                }
        }
}

static inline int get_data_buffer(struct s3cmci_host *host,
                                  u32 *bytes, u32 **pointer)
{
        struct scatterlist *sg;

        if (host->pio_active == XFER_NONE)
                return -EINVAL;

        if ((!host->mrq) || (!host->mrq->data))
                return -EINVAL;

        if (host->pio_sgptr >= host->mrq->data->sg_len) {
                dbg(host, dbg_debug, "no more buffers (%i/%i)\n",
                      host->pio_sgptr, host->mrq->data->sg_len);
                return -EBUSY;
        }
        sg = &host->mrq->data->sg[host->pio_sgptr];

        *bytes = sg->length;
        *pointer = sg_virt(sg);

        host->pio_sgptr++;

        dbg(host, dbg_sg, "new buffer (%i/%i)\n",
            host->pio_sgptr, host->mrq->data->sg_len);

        return 0;
}

static inline u32 fifo_count(struct s3cmci_host *host)
{
        u32 fifostat = readl(host->base + S3C2410_SDIFSTA);

        fifostat &= S3C2410_SDIFSTA_COUNTMASK;
        return fifostat;
}

static inline u32 fifo_free(struct s3cmci_host *host)
{
        u32 fifostat = readl(host->base + S3C2410_SDIFSTA);

        fifostat &= S3C2410_SDIFSTA_COUNTMASK;
        return 63 - fifostat;
}

/**
 * s3cmci_enable_irq - enable IRQ, after having disabled it.
 * @host: The device state.
 * @more: True if more IRQs are expected from transfer.
 *
 * Enable the main IRQ if needed after it has been disabled.
 *
 * The IRQ can be one of the following states:
 *      - disabled during IDLE
 *      - disabled whilst processing data
 *      - enabled during transfer
 *      - enabled whilst awaiting SDIO interrupt detection
 */
static void s3cmci_enable_irq(struct s3cmci_host *host, bool more)
{
        unsigned long flags;
        bool enable = false;

        local_irq_save(flags);

        host->irq_enabled = more;
        host->irq_disabled = false;

        enable = more | host->sdio_irqen;

        if (host->irq_state != enable) {
                host->irq_state = enable;

                if (enable)
                        enable_irq(host->irq);
                else
                        disable_irq(host->irq);
        }

        local_irq_restore(flags);
}

/**
 *
 */
static void s3cmci_disable_irq(struct s3cmci_host *host, bool transfer)
{
        unsigned long flags;

        local_irq_save(flags);

        /* pr_debug("%s: transfer %d\n", __func__, transfer); */

        host->irq_disabled = transfer;

        if (transfer && host->irq_state) {
                host->irq_state = false;
                disable_irq(host->irq);
        }

        local_irq_restore(flags);
}

static void do_pio_read(struct s3cmci_host *host)
{
        int res;
        u32 fifo;
        u32 *ptr;
        u32 fifo_words;
        void __iomem *from_ptr;

        /* write real prescaler to host, it might be set slow to fix */
        writel(host->prescaler, host->base + S3C2410_SDIPRE);

        from_ptr = host->base + host->sdidata;

        while ((fifo = fifo_count(host))) {
                if (!host->pio_bytes) {
                        res = get_data_buffer(host, &host->pio_bytes,
                                              &host->pio_ptr);
                        if (res) {
                                host->pio_active = XFER_NONE;
                                host->complete_what = COMPLETION_FINALIZE;

                                dbg(host, dbg_pio, "pio_read(): "
                                    "complete (no more data).\n");
                                return;
                        }

                        dbg(host, dbg_pio,
                            "pio_read(): new target: [%i]@[%p]\n",
                            host->pio_bytes, host->pio_ptr);
                }

                dbg(host, dbg_pio,
                    "pio_read(): fifo:[%02i] buffer:[%03i] dcnt:[%08X]\n",
                    fifo, host->pio_bytes,
                    readl(host->base + S3C2410_SDIDCNT));

                /* If we have reached the end of the block, we can
                 * read a word and get 1 to 3 bytes.  If we in the
                 * middle of the block, we have to read full words,
                 * otherwise we will write garbage, so round down to
                 * an even multiple of 4. */
                if (fifo >= host->pio_bytes)
                        fifo = host->pio_bytes;
                else
                        fifo -= fifo & 3;

                host->pio_bytes -= fifo;
                host->pio_count += fifo;

                fifo_words = fifo >> 2;
                ptr = host->pio_ptr;
                while (fifo_words--)
                        *ptr++ = readl(from_ptr);
                host->pio_ptr = ptr;

                if (fifo & 3) {
                        u32 n = fifo & 3;
                        u32 data = readl(from_ptr);
                        u8 *p = (u8 *)host->pio_ptr;

                        while (n--) {
                                *p++ = data;
                                data >>= 8;
                        }
                }
        }

        if (!host->pio_bytes) {
                res = get_data_buffer(host, &host->pio_bytes, &host->pio_ptr);
                if (res) {
                        dbg(host, dbg_pio,
                            "pio_read(): complete (no more buffers).\n");
                        host->pio_active = XFER_NONE;
                        host->complete_what = COMPLETION_FINALIZE;

                        return;
                }
        }

        enable_imask(host,
                     S3C2410_SDIIMSK_RXFIFOHALF | S3C2410_SDIIMSK_RXFIFOLAST);
}

static void do_pio_write(struct s3cmci_host *host)
{
        void __iomem *to_ptr;
        int res;
        u32 fifo;
        u32 *ptr;

        to_ptr = host->base + host->sdidata;

        while ((fifo = fifo_free(host)) > 3) {
                if (!host->pio_bytes) {
                        res = get_data_buffer(host, &host->pio_bytes,
                                                        &host->pio_ptr);
                        if (res) {
                                dbg(host, dbg_pio,
                                    "pio_write(): complete (no more data).\n");
                                host->pio_active = XFER_NONE;

                                return;
                        }

                        dbg(host, dbg_pio,
                            "pio_write(): new source: [%i]@[%p]\n",
                            host->pio_bytes, host->pio_ptr);

                }

                /* If we have reached the end of the block, we have to
                 * write exactly the remaining number of bytes.  If we
                 * in the middle of the block, we have to write full
                 * words, so round down to an even multiple of 4. */
                if (fifo >= host->pio_bytes)
                        fifo = host->pio_bytes;
                else
                        fifo -= fifo & 3;

                host->pio_bytes -= fifo;
                host->pio_count += fifo;

                fifo = (fifo + 3) >> 2;
                ptr = host->pio_ptr;
                while (fifo--)
                        writel(*ptr++, to_ptr);
                host->pio_ptr = ptr;
        }

        enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
}

static void pio_tasklet(unsigned long data)
{
        struct s3cmci_host *host = (struct s3cmci_host *) data;

        s3cmci_disable_irq(host, true);

        if (host->pio_active == XFER_WRITE)
                do_pio_write(host);

        if (host->pio_active == XFER_READ)
                do_pio_read(host);

        if (host->complete_what == COMPLETION_FINALIZE) {
                clear_imask(host);
                if (host->pio_active != XFER_NONE) {
                        dbg(host, dbg_err, "unfinished %s "
                            "- pio_count:[%u] pio_bytes:[%u]\n",
                            (host->pio_active == XFER_READ) ? "read" : "write",
                            host->pio_count, host->pio_bytes);

                        if (host->mrq->data)
                                host->mrq->data->error = -EINVAL;
                }

                s3cmci_enable_irq(host, false);
                finalize_request(host);
        } else
                s3cmci_enable_irq(host, true);
}

/*
 * ISR for SDI Interface IRQ
 * Communication between driver and ISR works as follows:
 *   host->mrq                  points to current request
 *   host->complete_what        Indicates when the request is considered done
 *     COMPLETION_CMDSENT         when the command was sent
 *     COMPLETION_RSPFIN          when a response was received
 *     COMPLETION_XFERFINISH      when the data transfer is finished
 *     COMPLETION_XFERFINISH_RSPFIN both of the above.
 *   host->complete_request     is the completion-object the driver waits for
 *
 * 1) Driver sets up host->mrq and host->complete_what
 * 2) Driver prepares the transfer
 * 3) Driver enables interrupts
 * 4) Driver starts transfer
 * 5) Driver waits for host->complete_rquest
 * 6) ISR checks for request status (errors and success)
 * 6) ISR sets host->mrq->cmd->error and host->mrq->data->error
 * 7) ISR completes host->complete_request
 * 8) ISR disables interrupts
 * 9) Driver wakes up and takes care of the request
 *
 * Note: "->error"-fields are expected to be set to 0 before the request
 *       was issued by mmc.c - therefore they are only set, when an error
 *       contition comes up
 */

static irqreturn_t s3cmci_irq(int irq, void *dev_id)
{
        struct s3cmci_host *host = dev_id;
        struct mmc_command *cmd;
        u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt, mci_imsk;
        u32 mci_cclear = 0, mci_dclear;
        unsigned long iflags;

        mci_dsta = readl(host->base + S3C2410_SDIDSTA);
        mci_imsk = readl(host->base + host->sdiimsk);

        if (mci_dsta & S3C2410_SDIDSTA_SDIOIRQDETECT) {
                if (mci_imsk & S3C2410_SDIIMSK_SDIOIRQ) {
                        mci_dclear = S3C2410_SDIDSTA_SDIOIRQDETECT;
                        writel(mci_dclear, host->base + S3C2410_SDIDSTA);

                        mmc_signal_sdio_irq(host->mmc);
                        return IRQ_HANDLED;
                }
        }

        spin_lock_irqsave(&host->complete_lock, iflags);

        mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
        mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
        mci_fsta = readl(host->base + S3C2410_SDIFSTA);
        mci_dclear = 0;

        if ((host->complete_what == COMPLETION_NONE) ||
            (host->complete_what == COMPLETION_FINALIZE)) {
                host->status = "nothing to complete";
                clear_imask(host);
                goto irq_out;
        }

        if (!host->mrq) {
                host->status = "no active mrq";
                clear_imask(host);
                goto irq_out;
        }

        cmd = host->cmd_is_stop ? host->mrq->stop : host->mrq->cmd;

        if (!cmd) {
                host->status = "no active cmd";
                clear_imask(host);
                goto irq_out;
        }

        if (!s3cmci_host_usedma(host)) {
                if ((host->pio_active == XFER_WRITE) &&
                    (mci_fsta & S3C2410_SDIFSTA_TFDET)) {

                        disable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
                        tasklet_schedule(&host->pio_tasklet);
                        host->status = "pio tx";
                }

                if ((host->pio_active == XFER_READ) &&
                    (mci_fsta & S3C2410_SDIFSTA_RFDET)) {

                        disable_imask(host,
                                      S3C2410_SDIIMSK_RXFIFOHALF |
                                      S3C2410_SDIIMSK_RXFIFOLAST);

                        tasklet_schedule(&host->pio_tasklet);
                        host->status = "pio rx";
                }
        }

        if (mci_csta & S3C2410_SDICMDSTAT_CMDTIMEOUT) {
                dbg(host, dbg_err, "CMDSTAT: error CMDTIMEOUT\n");
                cmd->error = -ETIMEDOUT;
                host->status = "error: command timeout";
                goto fail_transfer;
        }

        if (mci_csta & S3C2410_SDICMDSTAT_CMDSENT) {
                if (host->complete_what == COMPLETION_CMDSENT) {
                        host->status = "ok: command sent";
                        goto close_transfer;
                }

                mci_cclear |= S3C2410_SDICMDSTAT_CMDSENT;
        }

        if (mci_csta & S3C2410_SDICMDSTAT_CRCFAIL) {
                if (cmd->flags & MMC_RSP_CRC) {
                        if (host->mrq->cmd->flags & MMC_RSP_136) {
                                dbg(host, dbg_irq,
                                    "fixup: ignore CRC fail with long rsp\n");
                        } else {
                                /* note, we used to fail the transfer
                                 * here, but it seems that this is just
                                 * the hardware getting it wrong.
                                 *
                                 * cmd->error = -EILSEQ;
                                 * host->status = "error: bad command crc";
                                 * goto fail_transfer;
                                */
                        }
                }

                mci_cclear |= S3C2410_SDICMDSTAT_CRCFAIL;
        }

        if (mci_csta & S3C2410_SDICMDSTAT_RSPFIN) {
                if (host->complete_what == COMPLETION_RSPFIN) {
                        host->status = "ok: command response received";
                        goto close_transfer;
                }

                if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
                        host->complete_what = COMPLETION_XFERFINISH;

                mci_cclear |= S3C2410_SDICMDSTAT_RSPFIN;
        }

        /* errors handled after this point are only relevant
           when a data transfer is in progress */

        if (!cmd->data)
                goto clear_status_bits;

        /* Check for FIFO failure */
        if (host->is2440) {
                if (mci_fsta & S3C2440_SDIFSTA_FIFOFAIL) {
                        dbg(host, dbg_err, "FIFO failure\n");
                        host->mrq->data->error = -EILSEQ;
                        host->status = "error: 2440 fifo failure";
                        goto fail_transfer;
                }
        } else {
                if (mci_dsta & S3C2410_SDIDSTA_FIFOFAIL) {
                        dbg(host, dbg_err, "FIFO failure\n");
                        cmd->data->error = -EILSEQ;
                        host->status = "error:  fifo failure";
                        goto fail_transfer;
                }
        }

        if (mci_dsta & S3C2410_SDIDSTA_RXCRCFAIL) {
                dbg(host, dbg_err, "bad data crc (outgoing)\n");
                cmd->data->error = -EILSEQ;
                host->status = "error: bad data crc (outgoing)";
                goto fail_transfer;
        }

        if (mci_dsta & S3C2410_SDIDSTA_CRCFAIL) {
                dbg(host, dbg_err, "bad data crc (incoming)\n");
                cmd->data->error = -EILSEQ;
                host->status = "error: bad data crc (incoming)";
                goto fail_transfer;
        }

        if (mci_dsta & S3C2410_SDIDSTA_DATATIMEOUT) {
                dbg(host, dbg_err, "data timeout\n");
                cmd->data->error = -ETIMEDOUT;
                host->status = "error: data timeout";
                goto fail_transfer;
        }

        if (mci_dsta & S3C2410_SDIDSTA_XFERFINISH) {
                if (host->complete_what == COMPLETION_XFERFINISH) {
                        host->status = "ok: data transfer completed";
                        goto close_transfer;
                }

                if (host->complete_what == COMPLETION_XFERFINISH_RSPFIN)
                        host->complete_what = COMPLETION_RSPFIN;

                mci_dclear |= S3C2410_SDIDSTA_XFERFINISH;
        }

clear_status_bits:
        writel(mci_cclear, host->base + S3C2410_SDICMDSTAT);
        writel(mci_dclear, host->base + S3C2410_SDIDSTA);

        goto irq_out;

fail_transfer:
        host->pio_active = XFER_NONE;

close_transfer:
        host->complete_what = COMPLETION_FINALIZE;

        clear_imask(host);
        tasklet_schedule(&host->pio_tasklet);

        goto irq_out;

irq_out:
        dbg(host, dbg_irq,
            "csta:0x%08x dsta:0x%08x fsta:0x%08x dcnt:0x%08x status:%s.\n",
            mci_csta, mci_dsta, mci_fsta, mci_dcnt, host->status);

        spin_unlock_irqrestore(&host->complete_lock, iflags);
        return IRQ_HANDLED;

}

static void s3cmci_dma_done_callback(void *arg)
{
        struct s3cmci_host *host = arg;
        unsigned long iflags;

        BUG_ON(!host->mrq);
        BUG_ON(!host->mrq->data);

        spin_lock_irqsave(&host->complete_lock, iflags);

        dbg(host, dbg_dma, "DMA FINISHED\n");

        host->dma_complete = 1;
        host->complete_what = COMPLETION_FINALIZE;

        tasklet_schedule(&host->pio_tasklet);
        spin_unlock_irqrestore(&host->complete_lock, iflags);

}

static void finalize_request(struct s3cmci_host *host)
{
        struct mmc_request *mrq = host->mrq;
        struct mmc_command *cmd;
        int debug_as_failure = 0;

        if (host->complete_what != COMPLETION_FINALIZE)
                return;

        if (!mrq)
                return;
        cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;

        if (cmd->data && (cmd->error == 0) &&
            (cmd->data->error == 0)) {
                if (s3cmci_host_usedma(host) && (!host->dma_complete)) {
                        dbg(host, dbg_dma, "DMA Missing (%d)!\n",
                            host->dma_complete);
                        return;
                }
        }

        /* Read response from controller. */
        cmd->resp[0] = readl(host->base + S3C2410_SDIRSP0);
        cmd->resp[1] = readl(host->base + S3C2410_SDIRSP1);
        cmd->resp[2] = readl(host->base + S3C2410_SDIRSP2);
        cmd->resp[3] = readl(host->base + S3C2410_SDIRSP3);

        writel(host->prescaler, host->base + S3C2410_SDIPRE);

        if (cmd->error)
                debug_as_failure = 1;

        if (cmd->data && cmd->data->error)
                debug_as_failure = 1;

        dbg_dumpcmd(host, cmd, debug_as_failure);

        /* Cleanup controller */
        writel(0, host->base + S3C2410_SDICMDARG);
        writel(S3C2410_SDIDCON_STOP, host->base + S3C2410_SDIDCON);
        writel(0, host->base + S3C2410_SDICMDCON);
        clear_imask(host);

        if (cmd->data && cmd->error)
                cmd->data->error = cmd->error;

        if (cmd->data && cmd->data->stop && (!host->cmd_is_stop)) {
                host->cmd_is_stop = 1;
                s3cmci_send_request(host->mmc);
                return;
        }

        /* If we have no data transfer we are finished here */
        if (!mrq->data)
                goto request_done;

        /* Calculate the amout of bytes transfer if there was no error */
        if (mrq->data->error == 0) {
                mrq->data->bytes_xfered =
                        (mrq->data->blocks * mrq->data->blksz);
        } else {
                mrq->data->bytes_xfered = 0;
        }

        /* If we had an error while transferring data we flush the
         * DMA channel and the fifo to clear out any garbage. */
        if (mrq->data->error != 0) {
                if (s3cmci_host_usedma(host))
                        dmaengine_terminate_all(host->dma);

                if (host->is2440) {
                        /* Clear failure register and reset fifo. */
                        writel(S3C2440_SDIFSTA_FIFORESET |
                               S3C2440_SDIFSTA_FIFOFAIL,
                               host->base + S3C2410_SDIFSTA);
                } else {
                        u32 mci_con;

                        /* reset fifo */
                        mci_con = readl(host->base + S3C2410_SDICON);
                        mci_con |= S3C2410_SDICON_FIFORESET;

                        writel(mci_con, host->base + S3C2410_SDICON);
                }
        }

request_done:
        host->complete_what = COMPLETION_NONE;
        host->mrq = NULL;

        s3cmci_check_sdio_irq(host);
        mmc_request_done(host->mmc, mrq);
}

static void s3cmci_send_command(struct s3cmci_host *host,
                                        struct mmc_command *cmd)
{
        u32 ccon, imsk;

        imsk  = S3C2410_SDIIMSK_CRCSTATUS | S3C2410_SDIIMSK_CMDTIMEOUT |
                S3C2410_SDIIMSK_RESPONSEND | S3C2410_SDIIMSK_CMDSENT |
                S3C2410_SDIIMSK_RESPONSECRC;

        enable_imask(host, imsk);

        if (cmd->data)
                host->complete_what = COMPLETION_XFERFINISH_RSPFIN;
        else if (cmd->flags & MMC_RSP_PRESENT)
                host->complete_what = COMPLETION_RSPFIN;
        else
                host->complete_what = COMPLETION_CMDSENT;

        writel(cmd->arg, host->base + S3C2410_SDICMDARG);

        ccon  = cmd->opcode & S3C2410_SDICMDCON_INDEX;
        ccon |= S3C2410_SDICMDCON_SENDERHOST | S3C2410_SDICMDCON_CMDSTART;

        if (cmd->flags & MMC_RSP_PRESENT)
                ccon |= S3C2410_SDICMDCON_WAITRSP;

        if (cmd->flags & MMC_RSP_136)
                ccon |= S3C2410_SDICMDCON_LONGRSP;

        writel(ccon, host->base + S3C2410_SDICMDCON);
}

static int s3cmci_setup_data(struct s3cmci_host *host, struct mmc_data *data)
{
        u32 dcon, imsk, stoptries = 3;

        if ((data->blksz & 3) != 0) {
                /* We cannot deal with unaligned blocks with more than
                 * one block being transferred. */

                if (data->blocks > 1) {
                        pr_warn("%s: can't do non-word sized block transfers (blksz %d)\n",
                                __func__, data->blksz);
                        return -EINVAL;
                }
        }

        while (readl(host->base + S3C2410_SDIDSTA) &
               (S3C2410_SDIDSTA_TXDATAON | S3C2410_SDIDSTA_RXDATAON)) {

                dbg(host, dbg_err,
                    "mci_setup_data() transfer stillin progress.\n");

                writel(S3C2410_SDIDCON_STOP, host->base + S3C2410_SDIDCON);
                s3cmci_reset(host);

                if ((stoptries--) == 0) {
                        dbg_dumpregs(host, "DRF");
                        return -EINVAL;
                }
        }

        dcon  = data->blocks & S3C2410_SDIDCON_BLKNUM_MASK;

        if (s3cmci_host_usedma(host))
                dcon |= S3C2410_SDIDCON_DMAEN;

        if (host->bus_width == MMC_BUS_WIDTH_4)
                dcon |= S3C2410_SDIDCON_WIDEBUS;

        dcon |= S3C2410_SDIDCON_BLOCKMODE;

        if (data->flags & MMC_DATA_WRITE) {
                dcon |= S3C2410_SDIDCON_TXAFTERRESP;
                dcon |= S3C2410_SDIDCON_XFER_TXSTART;
        }

        if (data->flags & MMC_DATA_READ) {
                dcon |= S3C2410_SDIDCON_RXAFTERCMD;
                dcon |= S3C2410_SDIDCON_XFER_RXSTART;
        }

        if (host->is2440) {
                dcon |= S3C2440_SDIDCON_DS_WORD;
                dcon |= S3C2440_SDIDCON_DATSTART;
        }

        writel(dcon, host->base + S3C2410_SDIDCON);

        /* write BSIZE register */

        writel(data->blksz, host->base + S3C2410_SDIBSIZE);

        /* add to IMASK register */
        imsk = S3C2410_SDIIMSK_FIFOFAIL | S3C2410_SDIIMSK_DATACRC |
               S3C2410_SDIIMSK_DATATIMEOUT | S3C2410_SDIIMSK_DATAFINISH;

        enable_imask(host, imsk);

        /* write TIMER register */

        if (host->is2440) {
                writel(0x007FFFFF, host->base + S3C2410_SDITIMER);
        } else {
                writel(0x0000FFFF, host->base + S3C2410_SDITIMER);

                /* FIX: set slow clock to prevent timeouts on read */
                if (data->flags & MMC_DATA_READ)
                        writel(0xFF, host->base + S3C2410_SDIPRE);
        }

        return 0;
}

#define BOTH_DIR (MMC_DATA_WRITE | MMC_DATA_READ)

static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data)
{
        int rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;

        BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);

        host->pio_sgptr = 0;
        host->pio_bytes = 0;
        host->pio_count = 0;
        host->pio_active = rw ? XFER_WRITE : XFER_READ;

        if (rw) {
                do_pio_write(host);
                enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
        } else {
                enable_imask(host, S3C2410_SDIIMSK_RXFIFOHALF
                             | S3C2410_SDIIMSK_RXFIFOLAST);
        }

        return 0;
}

static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data *data)
{
        int rw = data->flags & MMC_DATA_WRITE;
        struct dma_async_tx_descriptor *desc;
        struct dma_slave_config conf = {
                .src_addr = host->mem->start + host->sdidata,
                .dst_addr = host->mem->start + host->sdidata,
                .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
                .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
        };

        BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);

        /* Restore prescaler value */
        writel(host->prescaler, host->base + S3C2410_SDIPRE);

        if (!rw)
                conf.direction = DMA_DEV_TO_MEM;
        else
                conf.direction = DMA_MEM_TO_DEV;

        dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
                   mmc_get_dma_dir(data));

        dmaengine_slave_config(host->dma, &conf);
        desc = dmaengine_prep_slave_sg(host->dma, data->sg, data->sg_len,
                conf.direction,
                DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
        if (!desc)
                goto unmap_exit;
        desc->callback = s3cmci_dma_done_callback;
        desc->callback_param = host;
        dmaengine_submit(desc);
        dma_async_issue_pending(host->dma);

        return 0;

unmap_exit:
        dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
                     mmc_get_dma_dir(data));
        return -ENOMEM;
}

static void s3cmci_send_request(struct mmc_host *mmc)
{
        struct s3cmci_host *host = mmc_priv(mmc);
        struct mmc_request *mrq = host->mrq;
        struct mmc_command *cmd = host->cmd_is_stop ? mrq->stop : mrq->cmd;

        host->ccnt++;
        prepare_dbgmsg(host, cmd, host->cmd_is_stop);

        /* Clear command, data and fifo status registers
           Fifo clear only necessary on 2440, but doesn't hurt on 2410
        */
        writel(0xFFFFFFFF, host->base + S3C2410_SDICMDSTAT);
        writel(0xFFFFFFFF, host->base + S3C2410_SDIDSTA);
        writel(0xFFFFFFFF, host->base + S3C2410_SDIFSTA);

        if (cmd->data) {
                int res = s3cmci_setup_data(host, cmd->data);

                host->dcnt++;

                if (res) {
                        dbg(host, dbg_err, "setup data error %d\n", res);
                        cmd->error = res;
                        cmd->data->error = res;

                        mmc_request_done(mmc, mrq);
                        return;
                }

                if (s3cmci_host_usedma(host))
                        res = s3cmci_prepare_dma(host, cmd->data);
                else
                        res = s3cmci_prepare_pio(host, cmd->data);

                if (res) {
                        dbg(host, dbg_err, "data prepare error %d\n", res);
                        cmd->error = res;
                        cmd->data->error = res;

                        mmc_request_done(mmc, mrq);
                        return;
                }
        }

        /* Send command */
        s3cmci_send_command(host, cmd);

        /* Enable Interrupt */
        s3cmci_enable_irq(host, true);
}

static void s3cmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct s3cmci_host *host = mmc_priv(mmc);

        host->status = "mmc request";
        host->cmd_is_stop = 0;
        host->mrq = mrq;

        if (mmc_gpio_get_cd(mmc) == 0) {
                dbg(host, dbg_err, "%s: no medium present\n", __func__);
                host->mrq->cmd->error = -ENOMEDIUM;
                mmc_request_done(mmc, mrq);
        } else
                s3cmci_send_request(mmc);
}

static void s3cmci_set_clk(struct s3cmci_host *host, struct mmc_ios *ios)
{
        u32 mci_psc;

        /* Set clock */
        for (mci_psc = 0; mci_psc < 255; mci_psc++) {
                host->real_rate = host->clk_rate / (host->clk_div*(mci_psc+1));

                if (host->real_rate <= ios->clock)
                        break;
        }

        if (mci_psc > 255)
                mci_psc = 255;

        host->prescaler = mci_psc;
        writel(host->prescaler, host->base + S3C2410_SDIPRE);

        /* If requested clock is 0, real_rate will be 0, too */
        if (ios->clock == 0)
                host->real_rate = 0;
}

static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct s3cmci_host *host = mmc_priv(mmc);
        u32 mci_con;

        /* Set the power state */

        mci_con = readl(host->base + S3C2410_SDICON);

        switch (ios->power_mode) {
        case MMC_POWER_ON:
        case MMC_POWER_UP:
                /* Configure GPE5...GPE10 pins in SD mode */
                if (!host->pdev->dev.of_node)
                        s3c_gpio_cfgall_range(S3C2410_GPE(5), 6, S3C_GPIO_SFN(2),
                                              S3C_GPIO_PULL_NONE);

                if (host->pdata->set_power)
                        host->pdata->set_power(ios->power_mode, ios->vdd);

                if (!host->is2440)
                        mci_con |= S3C2410_SDICON_FIFORESET;

                break;

        case MMC_POWER_OFF:
        default:
                if (!host->pdev->dev.of_node)
                        gpio_direction_output(S3C2410_GPE(5), 0);

                if (host->is2440)
                        mci_con |= S3C2440_SDICON_SDRESET;

                if (host->pdata->set_power)
                        host->pdata->set_power(ios->power_mode, ios->vdd);

                break;
        }

        s3cmci_set_clk(host, ios);

        /* Set CLOCK_ENABLE */
        if (ios->clock)
                mci_con |= S3C2410_SDICON_CLOCKTYPE;
        else
                mci_con &= ~S3C2410_SDICON_CLOCKTYPE;

        writel(mci_con, host->base + S3C2410_SDICON);

        if ((ios->power_mode == MMC_POWER_ON) ||
            (ios->power_mode == MMC_POWER_UP)) {
                dbg(host, dbg_conf, "running at %lukHz (requested: %ukHz).\n",
                        host->real_rate/1000, ios->clock/1000);
        } else {
                dbg(host, dbg_conf, "powered down.\n");
        }

        host->bus_width = ios->bus_width;
}

static void s3cmci_reset(struct s3cmci_host *host)
{
        u32 con = readl(host->base + S3C2410_SDICON);

        con |= S3C2440_SDICON_SDRESET;
        writel(con, host->base + S3C2410_SDICON);
}

static void s3cmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
{
        struct s3cmci_host *host = mmc_priv(mmc);
        unsigned long flags;
        u32 con;

        local_irq_save(flags);

        con = readl(host->base + S3C2410_SDICON);
        host->sdio_irqen = enable;

        if (enable == host->sdio_irqen)
                goto same_state;

        if (enable) {
                con |= S3C2410_SDICON_SDIOIRQ;
                enable_imask(host, S3C2410_SDIIMSK_SDIOIRQ);

                if (!host->irq_state && !host->irq_disabled) {
                        host->irq_state = true;
                        enable_irq(host->irq);
                }
        } else {
                disable_imask(host, S3C2410_SDIIMSK_SDIOIRQ);
                con &= ~S3C2410_SDICON_SDIOIRQ;

                if (!host->irq_enabled && host->irq_state) {
                        disable_irq_nosync(host->irq);
                        host->irq_state = false;
                }
        }

        writel(con, host->base + S3C2410_SDICON);

 same_state:
        local_irq_restore(flags);

        s3cmci_check_sdio_irq(host);
}

static const struct mmc_host_ops s3cmci_ops = {
        .request        = s3cmci_request,
        .set_ios        = s3cmci_set_ios,
        .get_ro         = mmc_gpio_get_ro,
        .get_cd         = mmc_gpio_get_cd,
        .enable_sdio_irq = s3cmci_enable_sdio_irq,
};

static struct s3c24xx_mci_pdata s3cmci_def_pdata = {
        /* This is currently here to avoid a number of if (host->pdata)
         * checks. Any zero fields to ensure reasonable defaults are picked. */
         .no_wprotect = 1,
         .no_detect = 1,
};

#ifdef CONFIG_ARM_S3C24XX_CPUFREQ

static int s3cmci_cpufreq_transition(struct notifier_block *nb,
                                     unsigned long val, void *data)
{
        struct s3cmci_host *host;
        struct mmc_host *mmc;
        unsigned long newclk;
        unsigned long flags;

        host = container_of(nb, struct s3cmci_host, freq_transition);
        newclk = clk_get_rate(host->clk);
        mmc = host->mmc;

        if ((val == CPUFREQ_PRECHANGE && newclk > host->clk_rate) ||
            (val == CPUFREQ_POSTCHANGE && newclk < host->clk_rate)) {
                spin_lock_irqsave(&mmc->lock, flags);

                host->clk_rate = newclk;

                if (mmc->ios.power_mode != MMC_POWER_OFF &&
                    mmc->ios.clock != 0)
                        s3cmci_set_clk(host, &mmc->ios);

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

        return 0;
}

static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)
{
        host->freq_transition.notifier_call = s3cmci_cpufreq_transition;

        return cpufreq_register_notifier(&host->freq_transition,
                                         CPUFREQ_TRANSITION_NOTIFIER);
}

static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)
{
        cpufreq_unregister_notifier(&host->freq_transition,
                                    CPUFREQ_TRANSITION_NOTIFIER);
}

#else
static inline int s3cmci_cpufreq_register(struct s3cmci_host *host)
{
        return 0;
}

static inline void s3cmci_cpufreq_deregister(struct s3cmci_host *host)
{
}
#endif


#ifdef CONFIG_DEBUG_FS

static int s3cmci_state_show(struct seq_file *seq, void *v)
{
        struct s3cmci_host *host = seq->private;

        seq_printf(seq, "Register base = 0x%08x\n", (u32)host->base);
        seq_printf(seq, "Clock rate = %ld\n", host->clk_rate);
        seq_printf(seq, "Prescale = %d\n", host->prescaler);
        seq_printf(seq, "is2440 = %d\n", host->is2440);
        seq_printf(seq, "IRQ = %d\n", host->irq);
        seq_printf(seq, "IRQ enabled = %d\n", host->irq_enabled);
        seq_printf(seq, "IRQ disabled = %d\n", host->irq_disabled);
        seq_printf(seq, "IRQ state = %d\n", host->irq_state);
        seq_printf(seq, "CD IRQ = %d\n", host->irq_cd);
        seq_printf(seq, "Do DMA = %d\n", s3cmci_host_usedma(host));
        seq_printf(seq, "SDIIMSK at %d\n", host->sdiimsk);
        seq_printf(seq, "SDIDATA at %d\n", host->sdidata);

        return 0;
}

DEFINE_SHOW_ATTRIBUTE(s3cmci_state);

#define DBG_REG(_r) { .addr = S3C2410_SDI##_r, .name = #_r }

struct s3cmci_reg {
        unsigned short  addr;
        unsigned char   *name;
};

static const struct s3cmci_reg debug_regs[] = {
        DBG_REG(CON),
        DBG_REG(PRE),
        DBG_REG(CMDARG),
        DBG_REG(CMDCON),
        DBG_REG(CMDSTAT),
        DBG_REG(RSP0),
        DBG_REG(RSP1),
        DBG_REG(RSP2),
        DBG_REG(RSP3),
        DBG_REG(TIMER),
        DBG_REG(BSIZE),
        DBG_REG(DCON),
        DBG_REG(DCNT),
        DBG_REG(DSTA),
        DBG_REG(FSTA),
        {}
};

static int s3cmci_regs_show(struct seq_file *seq, void *v)
{
        struct s3cmci_host *host = seq->private;
        const struct s3cmci_reg *rptr = debug_regs;

        for (; rptr->name; rptr++)
                seq_printf(seq, "SDI%s\t=0x%08x\n", rptr->name,
                           readl(host->base + rptr->addr));

        seq_printf(seq, "SDIIMSK\t=0x%08x\n", readl(host->base + host->sdiimsk));

        return 0;
}

DEFINE_SHOW_ATTRIBUTE(s3cmci_regs);

static void s3cmci_debugfs_attach(struct s3cmci_host *host)
{
        struct device *dev = &host->pdev->dev;
        struct dentry *root;

        root = debugfs_create_dir(dev_name(dev), NULL);
        host->debug_root = root;

        debugfs_create_file("state", 0444, root, host, &s3cmci_state_fops);
        debugfs_create_file("regs", 0444, root, host, &s3cmci_regs_fops);
}

static void s3cmci_debugfs_remove(struct s3cmci_host *host)
{
        debugfs_remove_recursive(host->debug_root);
}

#else
static inline void s3cmci_debugfs_attach(struct s3cmci_host *host) { }
static inline void s3cmci_debugfs_remove(struct s3cmci_host *host) { }

#endif /* CONFIG_DEBUG_FS */

static int s3cmci_probe_pdata(struct s3cmci_host *host)
{
        struct platform_device *pdev = host->pdev;
        struct mmc_host *mmc = host->mmc;
        struct s3c24xx_mci_pdata *pdata;
        int i, ret;

        host->is2440 = platform_get_device_id(pdev)->driver_data;

        for (i = S3C2410_GPE(5); i <= S3C2410_GPE(10); i++) {
                ret = gpio_request(i, dev_name(&pdev->dev));
                if (ret) {
                        dev_err(&pdev->dev, "failed to get gpio %d\n", i);

                        for (i--; i >= S3C2410_GPE(5); i--)
                                gpio_free(i);

                        return ret;
                }
        }

        if (!pdev->dev.platform_data)
                pdev->dev.platform_data = &s3cmci_def_pdata;

        pdata = pdev->dev.platform_data;

        if (pdata->no_wprotect)
                mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;

        if (pdata->no_detect)
                mmc->caps |= MMC_CAP_NEEDS_POLL;

        if (pdata->wprotect_invert)
                mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;

        /* If we get -ENOENT we have no card detect GPIO line */
        ret = mmc_gpiod_request_cd(mmc, "cd", 0, false, 0);
        if (ret != -ENOENT) {
                dev_err(&pdev->dev, "error requesting GPIO for CD %d\n",
                        ret);
                return ret;
        }

        ret = mmc_gpiod_request_ro(host->mmc, "wp", 0, 0);
        if (ret != -ENOENT) {
                dev_err(&pdev->dev, "error requesting GPIO for WP %d\n",
                        ret);
                return ret;
        }

        return 0;
}

static int s3cmci_probe_dt(struct s3cmci_host *host)
{
        struct platform_device *pdev = host->pdev;
        struct s3c24xx_mci_pdata *pdata;
        struct mmc_host *mmc = host->mmc;
        int ret;

        host->is2440 = (int) of_device_get_match_data(&pdev->dev);

        ret = mmc_of_parse(mmc);
        if (ret)
                return ret;

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

        pdev->dev.platform_data = pdata;

        return 0;
}

static int s3cmci_probe(struct platform_device *pdev)
{
        struct s3cmci_host *host;
        struct mmc_host *mmc;
        int ret;
        int i;

        mmc = mmc_alloc_host(sizeof(struct s3cmci_host), &pdev->dev);
        if (!mmc) {
                ret = -ENOMEM;
                goto probe_out;
        }

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

        if (pdev->dev.of_node)
                ret = s3cmci_probe_dt(host);
        else
                ret = s3cmci_probe_pdata(host);

        if (ret)
                goto probe_free_host;

        host->pdata = pdev->dev.platform_data;

        spin_lock_init(&host->complete_lock);
        tasklet_init(&host->pio_tasklet, pio_tasklet, (unsigned long) host);

        if (host->is2440) {
                host->sdiimsk   = S3C2440_SDIIMSK;
                host->sdidata   = S3C2440_SDIDATA;
                host->clk_div   = 1;
        } else {
                host->sdiimsk   = S3C2410_SDIIMSK;
                host->sdidata   = S3C2410_SDIDATA;
                host->clk_div   = 2;
        }

        host->complete_what     = COMPLETION_NONE;
        host->pio_active        = XFER_NONE;

        host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!host->mem) {
                dev_err(&pdev->dev,
                        "failed to get io memory region resource.\n");

                ret = -ENOENT;
                goto probe_free_gpio;
        }

        host->mem = request_mem_region(host->mem->start,
                                       resource_size(host->mem), pdev->name);

        if (!host->mem) {
                dev_err(&pdev->dev, "failed to request io memory region.\n");
                ret = -ENOENT;
                goto probe_free_gpio;
        }

        host->base = ioremap(host->mem->start, resource_size(host->mem));
        if (!host->base) {
                dev_err(&pdev->dev, "failed to ioremap() io memory region.\n");
                ret = -EINVAL;
                goto probe_free_mem_region;
        }

        host->irq = platform_get_irq(pdev, 0);
        if (host->irq <= 0) {
                ret = -EINVAL;
                goto probe_iounmap;
        }

        if (request_irq(host->irq, s3cmci_irq, 0, DRIVER_NAME, host)) {
                dev_err(&pdev->dev, "failed to request mci interrupt.\n");
                ret = -ENOENT;
                goto probe_iounmap;
        }

        /* We get spurious interrupts even when we have set the IMSK
         * register to ignore everything, so use disable_irq() to make
         * ensure we don't lock the system with un-serviceable requests. */

        disable_irq(host->irq);
        host->irq_state = false;

        /* Depending on the dma state, get a DMA channel to use. */

        if (s3cmci_host_usedma(host)) {
                host->dma = dma_request_chan(&pdev->dev, "rx-tx");
                ret = PTR_ERR_OR_ZERO(host->dma);
                if (ret) {
                        dev_err(&pdev->dev, "cannot get DMA channel.\n");
                        goto probe_free_irq;
                }
        }

        host->clk = clk_get(&pdev->dev, "sdi");
        if (IS_ERR(host->clk)) {
                dev_err(&pdev->dev, "failed to find clock source.\n");
                ret = PTR_ERR(host->clk);
                host->clk = NULL;
                goto probe_free_dma;
        }

        ret = clk_prepare_enable(host->clk);
        if (ret) {
                dev_err(&pdev->dev, "failed to enable clock source.\n");
                goto clk_free;
        }

        host->clk_rate = clk_get_rate(host->clk);

        mmc->ops        = &s3cmci_ops;
        mmc->ocr_avail  = MMC_VDD_32_33 | MMC_VDD_33_34;
#ifdef CONFIG_MMC_S3C_HW_SDIO_IRQ
        mmc->caps       = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
#else
        mmc->caps       = MMC_CAP_4_BIT_DATA;
#endif
        mmc->f_min      = host->clk_rate / (host->clk_div * 256);
        mmc->f_max      = host->clk_rate / host->clk_div;

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

        mmc->max_blk_count      = 4095;
        mmc->max_blk_size       = 4095;
        mmc->max_req_size       = 4095 * 512;
        mmc->max_seg_size       = mmc->max_req_size;

        mmc->max_segs           = 128;

        dbg(host, dbg_debug,
            "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%p.\n",
            (host->is2440?"2440":""),
            host->base, host->irq, host->irq_cd, host->dma);

        ret = s3cmci_cpufreq_register(host);
        if (ret) {
                dev_err(&pdev->dev, "failed to register cpufreq\n");
                goto free_dmabuf;
        }

        ret = mmc_add_host(mmc);
        if (ret) {
                dev_err(&pdev->dev, "failed to add mmc host.\n");
                goto free_cpufreq;
        }

        s3cmci_debugfs_attach(host);

        platform_set_drvdata(pdev, mmc);
        dev_info(&pdev->dev, "%s - using %s, %s SDIO IRQ\n", mmc_hostname(mmc),
                 s3cmci_host_usedma(host) ? "dma" : "pio",
                 mmc->caps & MMC_CAP_SDIO_IRQ ? "hw" : "sw");

        return 0;

 free_cpufreq:
        s3cmci_cpufreq_deregister(host);

 free_dmabuf:
        clk_disable_unprepare(host->clk);

 clk_free:
        clk_put(host->clk);

 probe_free_dma:
        if (s3cmci_host_usedma(host))
                dma_release_channel(host->dma);

 probe_free_irq:
        free_irq(host->irq, host);

 probe_iounmap:
        iounmap(host->base);

 probe_free_mem_region:
        release_mem_region(host->mem->start, resource_size(host->mem));

 probe_free_gpio:
        if (!pdev->dev.of_node)
                for (i = S3C2410_GPE(5); i <= S3C2410_GPE(10); i++)
                        gpio_free(i);

 probe_free_host:
        mmc_free_host(mmc);

 probe_out:
        return ret;
}

static void s3cmci_shutdown(struct platform_device *pdev)
{
        struct mmc_host *mmc = platform_get_drvdata(pdev);
        struct s3cmci_host *host = mmc_priv(mmc);

        if (host->irq_cd >= 0)
                free_irq(host->irq_cd, host);

        s3cmci_debugfs_remove(host);
        s3cmci_cpufreq_deregister(host);
        mmc_remove_host(mmc);
        clk_disable_unprepare(host->clk);
}

static int s3cmci_remove(struct platform_device *pdev)
{
        struct mmc_host         *mmc  = platform_get_drvdata(pdev);
        struct s3cmci_host      *host = mmc_priv(mmc);
        int i;

        s3cmci_shutdown(pdev);

        clk_put(host->clk);

        tasklet_disable(&host->pio_tasklet);

        if (s3cmci_host_usedma(host))
                dma_release_channel(host->dma);

        free_irq(host->irq, host);

        if (!pdev->dev.of_node)
                for (i = S3C2410_GPE(5); i <= S3C2410_GPE(10); i++)
                        gpio_free(i);

        iounmap(host->base);
        release_mem_region(host->mem->start, resource_size(host->mem));

        mmc_free_host(mmc);
        return 0;
}

static const struct of_device_id s3cmci_dt_match[] = {
        {
                .compatible = "samsung,s3c2410-sdi",
                .data = (void *)0,
        },
        {
                .compatible = "samsung,s3c2412-sdi",
                .data = (void *)1,
        },
        {
                .compatible = "samsung,s3c2440-sdi",
                .data = (void *)1,
        },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, s3cmci_dt_match);

static const struct platform_device_id s3cmci_driver_ids[] = {
        {
                .name   = "s3c2410-sdi",
                .driver_data    = 0,
        }, {
                .name   = "s3c2412-sdi",
                .driver_data    = 1,
        }, {
                .name   = "s3c2440-sdi",
                .driver_data    = 1,
        },
        { }
};

MODULE_DEVICE_TABLE(platform, s3cmci_driver_ids);

static struct platform_driver s3cmci_driver = {
        .driver = {
                .name   = "s3c-sdi",
                .of_match_table = s3cmci_dt_match,
        },
        .id_table       = s3cmci_driver_ids,
        .probe          = s3cmci_probe,
        .remove         = s3cmci_remove,
        .shutdown       = s3cmci_shutdown,
};

module_platform_driver(s3cmci_driver);

MODULE_DESCRIPTION("Samsung S3C MMC/SD Card Interface driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Thomas Kleffel <tk@maintech.de>, Ben Dooks <ben-linux@fluff.org>");