// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/drivers/mmc/host/au1xmmc.c - AU1XX0 MMC driver
 *
 *  Copyright (c) 2005, Advanced Micro Devices, Inc.
 *
 *  Developed with help from the 2.4.30 MMC AU1XXX controller including
 *  the following copyright notices:
 *     Copyright (c) 2003-2004 Embedded Edge, LLC.
 *     Portions Copyright (C) 2002 Embedix, Inc
 *     Copyright 2002 Hewlett-Packard Company

 *  2.6 version of this driver inspired by:
 *     (drivers/mmc/wbsd.c) Copyright (C) 2004-2005 Pierre Ossman,
 *     All Rights Reserved.
 *     (drivers/mmc/pxa.c) Copyright (C) 2003 Russell King,
 *     All Rights Reserved.
 *

 */

/* Why don't we use the SD controllers' carddetect feature?
 *
 * From the AU1100 MMC application guide:
 * If the Au1100-based design is intended to support both MultiMediaCards
 * and 1- or 4-data bit SecureDigital cards, then the solution is to
 * connect a weak (560KOhm) pull-up resistor to connector pin 1.
 * In doing so, a MMC card never enters SPI-mode communications,
 * but now the SecureDigital card-detect feature of CD/DAT3 is ineffective
 * (the low to high transition will not occur).
 */

#include <linux/clk.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/highmem.h>
#include <linux/leds.h>
#include <linux/mmc/host.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include <asm/io.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/au1xxx_dbdma.h>
#include <asm/mach-au1x00/au1100_mmc.h>

#define DRIVER_NAME "au1xxx-mmc"

/* Set this to enable special debugging macros */
/* #define DEBUG */

#ifdef DEBUG
#define DBG(fmt, idx, args...)  \
        pr_debug("au1xmmc(%d): DEBUG: " fmt, idx, ##args)
#else
#define DBG(fmt, idx, args...) do {} while (0)
#endif

/* Hardware definitions */
#define AU1XMMC_DESCRIPTOR_COUNT 1

/* max DMA seg size: 64KB on Au1100, 4MB on Au1200 */
#define AU1100_MMC_DESCRIPTOR_SIZE 0x0000ffff
#define AU1200_MMC_DESCRIPTOR_SIZE 0x003fffff

#define AU1XMMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \
                     MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \
                     MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36)

/* This gives us a hard value for the stop command that we can write directly
 * to the command register.
 */
#define STOP_CMD        \
        (SD_CMD_RT_1B | SD_CMD_CT_7 | (0xC << SD_CMD_CI_SHIFT) | SD_CMD_GO)

/* This is the set of interrupts that we configure by default. */
#define AU1XMMC_INTERRUPTS                              \
        (SD_CONFIG_SC | SD_CONFIG_DT | SD_CONFIG_RAT |  \
         SD_CONFIG_CR | SD_CONFIG_I)

/* The poll event (looking for insert/remove events runs twice a second. */
#define AU1XMMC_DETECT_TIMEOUT (HZ/2)

struct au1xmmc_host {
        struct mmc_host *mmc;
        struct mmc_request *mrq;

        u32 flags;
        void __iomem *iobase;
        u32 clock;
        u32 bus_width;
        u32 power_mode;

        int status;

        struct {
                int len;
                int dir;
        } dma;

        struct {
                int index;
                int offset;
                int len;
        } pio;

        u32 tx_chan;
        u32 rx_chan;

        int irq;

        struct work_struct finish_bh_work;
        struct work_struct data_bh_work;
        struct au1xmmc_platform_data *platdata;
        struct platform_device *pdev;
        struct resource *ioarea;
        struct clk *clk;
};

/* Status flags used by the host structure */
#define HOST_F_XMIT     0x0001
#define HOST_F_RECV     0x0002
#define HOST_F_DMA      0x0010
#define HOST_F_DBDMA    0x0020
#define HOST_F_ACTIVE   0x0100
#define HOST_F_STOP     0x1000

#define HOST_S_IDLE     0x0001
#define HOST_S_CMD      0x0002
#define HOST_S_DATA     0x0003
#define HOST_S_STOP     0x0004

/* Easy access macros */
#define HOST_STATUS(h)  ((h)->iobase + SD_STATUS)
#define HOST_CONFIG(h)  ((h)->iobase + SD_CONFIG)
#define HOST_ENABLE(h)  ((h)->iobase + SD_ENABLE)
#define HOST_TXPORT(h)  ((h)->iobase + SD_TXPORT)
#define HOST_RXPORT(h)  ((h)->iobase + SD_RXPORT)
#define HOST_CMDARG(h)  ((h)->iobase + SD_CMDARG)
#define HOST_BLKSIZE(h) ((h)->iobase + SD_BLKSIZE)
#define HOST_CMD(h)     ((h)->iobase + SD_CMD)
#define HOST_CONFIG2(h) ((h)->iobase + SD_CONFIG2)
#define HOST_TIMEOUT(h) ((h)->iobase + SD_TIMEOUT)
#define HOST_DEBUG(h)   ((h)->iobase + SD_DEBUG)

#define DMA_CHANNEL(h)  \
        (((h)->flags & HOST_F_XMIT) ? (h)->tx_chan : (h)->rx_chan)

static inline int has_dbdma(void)
{
        switch (alchemy_get_cputype()) {
        case ALCHEMY_CPU_AU1200:
        case ALCHEMY_CPU_AU1300:
                return 1;
        default:
                return 0;
        }
}

static inline void IRQ_ON(struct au1xmmc_host *host, u32 mask)
{
        u32 val = __raw_readl(HOST_CONFIG(host));
        val |= mask;
        __raw_writel(val, HOST_CONFIG(host));
        wmb(); /* drain writebuffer */
}

static inline void FLUSH_FIFO(struct au1xmmc_host *host)
{
        u32 val = __raw_readl(HOST_CONFIG2(host));

        __raw_writel(val | SD_CONFIG2_FF, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */
        mdelay(1);

        /* SEND_STOP will turn off clock control - this re-enables it */
        val &= ~SD_CONFIG2_DF;

        __raw_writel(val, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */
}

static inline void IRQ_OFF(struct au1xmmc_host *host, u32 mask)
{
        u32 val = __raw_readl(HOST_CONFIG(host));
        val &= ~mask;
        __raw_writel(val, HOST_CONFIG(host));
        wmb(); /* drain writebuffer */
}

static inline void SEND_STOP(struct au1xmmc_host *host)
{
        u32 config2;

        WARN_ON(host->status != HOST_S_DATA);
        host->status = HOST_S_STOP;

        config2 = __raw_readl(HOST_CONFIG2(host));
        __raw_writel(config2 | SD_CONFIG2_DF, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */

        /* Send the stop command */
        __raw_writel(STOP_CMD, HOST_CMD(host));
        wmb(); /* drain writebuffer */
}

static void au1xmmc_set_power(struct au1xmmc_host *host, int state)
{
        if (host->platdata && host->platdata->set_power)
                host->platdata->set_power(host->mmc, state);
}

static int au1xmmc_card_inserted(struct mmc_host *mmc)
{
        struct au1xmmc_host *host = mmc_priv(mmc);

        if (host->platdata && host->platdata->card_inserted)
                return !!host->platdata->card_inserted(host->mmc);

        return -ENOSYS;
}

static int au1xmmc_card_readonly(struct mmc_host *mmc)
{
        struct au1xmmc_host *host = mmc_priv(mmc);

        if (host->platdata && host->platdata->card_readonly)
                return !!host->platdata->card_readonly(mmc);

        return -ENOSYS;
}

static void au1xmmc_finish_request(struct au1xmmc_host *host)
{
        struct mmc_request *mrq = host->mrq;

        host->mrq = NULL;
        host->flags &= HOST_F_ACTIVE | HOST_F_DMA;

        host->dma.len = 0;
        host->dma.dir = 0;

        host->pio.index  = 0;
        host->pio.offset = 0;
        host->pio.len = 0;

        host->status = HOST_S_IDLE;

        mmc_request_done(host->mmc, mrq);
}

static void au1xmmc_finish_bh_work(struct work_struct *t)
{
        struct au1xmmc_host *host = from_work(host, t, finish_bh_work);
        au1xmmc_finish_request(host);
}

static int au1xmmc_send_command(struct au1xmmc_host *host,
                                struct mmc_command *cmd, struct mmc_data *data)
{
        u32 mmccmd = (cmd->opcode << SD_CMD_CI_SHIFT);

        switch (mmc_resp_type(cmd)) {
        case MMC_RSP_NONE:
                break;
        case MMC_RSP_R1:
                mmccmd |= SD_CMD_RT_1;
                break;
        case MMC_RSP_R1B:
                mmccmd |= SD_CMD_RT_1B;
                break;
        case MMC_RSP_R2:
                mmccmd |= SD_CMD_RT_2;
                break;
        case MMC_RSP_R3:
                mmccmd |= SD_CMD_RT_3;
                break;
        default:
                pr_info("au1xmmc: unhandled response type %02x\n",
                        mmc_resp_type(cmd));
                return -EINVAL;
        }

        if (data) {
                if (data->flags & MMC_DATA_READ) {
                        if (data->blocks > 1)
                                mmccmd |= SD_CMD_CT_4;
                        else
                                mmccmd |= SD_CMD_CT_2;
                } else if (data->flags & MMC_DATA_WRITE) {
                        if (data->blocks > 1)
                                mmccmd |= SD_CMD_CT_3;
                        else
                                mmccmd |= SD_CMD_CT_1;
                }
        }

        __raw_writel(cmd->arg, HOST_CMDARG(host));
        wmb(); /* drain writebuffer */

        __raw_writel((mmccmd | SD_CMD_GO), HOST_CMD(host));
        wmb(); /* drain writebuffer */

        /* Wait for the command to go on the line */
        while (__raw_readl(HOST_CMD(host)) & SD_CMD_GO)
                /* nop */;

        return 0;
}

static void au1xmmc_data_complete(struct au1xmmc_host *host, u32 status)
{
        struct mmc_request *mrq = host->mrq;
        struct mmc_data *data;
        u32 crc;

        WARN_ON((host->status != HOST_S_DATA) && (host->status != HOST_S_STOP));

        if (host->mrq == NULL)
                return;

        data = mrq->cmd->data;

        if (status == 0)
                status = __raw_readl(HOST_STATUS(host));

        /* The transaction is really over when the SD_STATUS_DB bit is clear */
        while ((host->flags & HOST_F_XMIT) && (status & SD_STATUS_DB))
                status = __raw_readl(HOST_STATUS(host));

        data->error = 0;
        dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, host->dma.dir);

        /* Process any errors */
        crc = (status & (SD_STATUS_WC | SD_STATUS_RC));
        if (host->flags & HOST_F_XMIT)
                crc |= ((status & 0x07) == 0x02) ? 0 : 1;

        if (crc)
                data->error = -EILSEQ;

        /* Clear the CRC bits */
        __raw_writel(SD_STATUS_WC | SD_STATUS_RC, HOST_STATUS(host));

        data->bytes_xfered = 0;

        if (!data->error) {
                if (host->flags & (HOST_F_DMA | HOST_F_DBDMA)) {
                        u32 chan = DMA_CHANNEL(host);

                        chan_tab_t *c = *((chan_tab_t **)chan);
                        au1x_dma_chan_t *cp = c->chan_ptr;
                        data->bytes_xfered = cp->ddma_bytecnt;
                } else
                        data->bytes_xfered =
                                (data->blocks * data->blksz) - host->pio.len;
        }

        au1xmmc_finish_request(host);
}

static void au1xmmc_data_bh_work(struct work_struct *t)
{
        struct au1xmmc_host *host = from_work(host, t, data_bh_work);

        u32 status = __raw_readl(HOST_STATUS(host));
        au1xmmc_data_complete(host, status);
}

#define AU1XMMC_MAX_TRANSFER 8

static void au1xmmc_send_pio(struct au1xmmc_host *host)
{
        struct mmc_data *data;
        int sg_len, max, count;
        unsigned char *sg_ptr, val;
        u32 status;
        struct scatterlist *sg;

        data = host->mrq->data;

        if (!(host->flags & HOST_F_XMIT))
                return;

        /* This is the pointer to the data buffer */
        sg = &data->sg[host->pio.index];
        sg_ptr = kmap_local_page(sg_page(sg)) + sg->offset + host->pio.offset;

        /* This is the space left inside the buffer */
        sg_len = data->sg[host->pio.index].length - host->pio.offset;

        /* Check if we need less than the size of the sg_buffer */
        max = (sg_len > host->pio.len) ? host->pio.len : sg_len;
        if (max > AU1XMMC_MAX_TRANSFER)
                max = AU1XMMC_MAX_TRANSFER;

        for (count = 0; count < max; count++) {
                status = __raw_readl(HOST_STATUS(host));

                if (!(status & SD_STATUS_TH))
                        break;

                val = sg_ptr[count];

                __raw_writel((unsigned long)val, HOST_TXPORT(host));
                wmb(); /* drain writebuffer */
        }
        kunmap_local(sg_ptr);

        host->pio.len -= count;
        host->pio.offset += count;

        if (count == sg_len) {
                host->pio.index++;
                host->pio.offset = 0;
        }

        if (host->pio.len == 0) {
                IRQ_OFF(host, SD_CONFIG_TH);

                if (host->flags & HOST_F_STOP)
                        SEND_STOP(host);

                queue_work(system_bh_wq, &host->data_bh_work);
        }
}

static void au1xmmc_receive_pio(struct au1xmmc_host *host)
{
        struct mmc_data *data;
        int max, count, sg_len = 0;
        unsigned char *sg_ptr = NULL;
        u32 status, val;
        struct scatterlist *sg;

        data = host->mrq->data;

        if (!(host->flags & HOST_F_RECV))
                return;

        max = host->pio.len;

        if (host->pio.index < host->dma.len) {
                sg = &data->sg[host->pio.index];
                sg_ptr = kmap_local_page(sg_page(sg)) + sg->offset + host->pio.offset;

                /* This is the space left inside the buffer */
                sg_len = sg_dma_len(&data->sg[host->pio.index]) - host->pio.offset;

                /* Check if we need less than the size of the sg_buffer */
                if (sg_len < max)
                        max = sg_len;
        }

        if (max > AU1XMMC_MAX_TRANSFER)
                max = AU1XMMC_MAX_TRANSFER;

        for (count = 0; count < max; count++) {
                status = __raw_readl(HOST_STATUS(host));

                if (!(status & SD_STATUS_NE))
                        break;

                if (status & SD_STATUS_RC) {
                        DBG("RX CRC Error [%d + %d].\n", host->pdev->id,
                                        host->pio.len, count);
                        break;
                }

                if (status & SD_STATUS_RO) {
                        DBG("RX Overrun [%d + %d]\n", host->pdev->id,
                                        host->pio.len, count);
                        break;
                }
                else if (status & SD_STATUS_RU) {
                        DBG("RX Underrun [%d + %d]\n", host->pdev->id,
                                        host->pio.len,  count);
                        break;
                }

                val = __raw_readl(HOST_RXPORT(host));

                if (sg_ptr)
                        sg_ptr[count] = (unsigned char)(val & 0xFF);
        }
        if (sg_ptr)
                kunmap_local(sg_ptr);

        host->pio.len -= count;
        host->pio.offset += count;

        if (sg_len && count == sg_len) {
                host->pio.index++;
                host->pio.offset = 0;
        }

        if (host->pio.len == 0) {
                /* IRQ_OFF(host, SD_CONFIG_RA | SD_CONFIG_RF); */
                IRQ_OFF(host, SD_CONFIG_NE);

                if (host->flags & HOST_F_STOP)
                        SEND_STOP(host);

                queue_work(system_bh_wq, &host->data_bh_work);
        }
}

/* This is called when a command has been completed - grab the response
 * and check for errors.  Then start the data transfer if it is indicated.
 */
static void au1xmmc_cmd_complete(struct au1xmmc_host *host, u32 status)
{
        struct mmc_request *mrq = host->mrq;
        struct mmc_command *cmd;
        u32 r[4];
        int i, trans;

        if (!host->mrq)
                return;

        cmd = mrq->cmd;
        cmd->error = 0;

        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        r[0] = __raw_readl(host->iobase + SD_RESP3);
                        r[1] = __raw_readl(host->iobase + SD_RESP2);
                        r[2] = __raw_readl(host->iobase + SD_RESP1);
                        r[3] = __raw_readl(host->iobase + SD_RESP0);

                        /* The CRC is omitted from the response, so really
                         * we only got 120 bytes, but the engine expects
                         * 128 bits, so we have to shift things up.
                         */
                        for (i = 0; i < 4; i++) {
                                cmd->resp[i] = (r[i] & 0x00FFFFFF) << 8;
                                if (i != 3)
                                        cmd->resp[i] |= (r[i + 1] & 0xFF000000) >> 24;
                        }
                } else {
                        /* Technically, we should be getting all 48 bits of
                         * the response (SD_RESP1 + SD_RESP2), but because
                         * our response omits the CRC, our data ends up
                         * being shifted 8 bits to the right.  In this case,
                         * that means that the OSR data starts at bit 31,
                         * so we can just read RESP0 and return that.
                         */
                        cmd->resp[0] = __raw_readl(host->iobase + SD_RESP0);
                }
        }

        /* Figure out errors */
        if (status & (SD_STATUS_SC | SD_STATUS_WC | SD_STATUS_RC))
                cmd->error = -EILSEQ;

        trans = host->flags & (HOST_F_XMIT | HOST_F_RECV);

        if (!trans || cmd->error) {
                IRQ_OFF(host, SD_CONFIG_TH | SD_CONFIG_RA | SD_CONFIG_RF);
                queue_work(system_bh_wq, &host->finish_bh_work);
                return;
        }

        host->status = HOST_S_DATA;

        if ((host->flags & (HOST_F_DMA | HOST_F_DBDMA))) {
                u32 channel = DMA_CHANNEL(host);

                /* Start the DBDMA as soon as the buffer gets something in it */

                if (host->flags & HOST_F_RECV) {
                        u32 mask = SD_STATUS_DB | SD_STATUS_NE;

                        while((status & mask) != mask)
                                status = __raw_readl(HOST_STATUS(host));
                }

                au1xxx_dbdma_start(channel);
        }
}

static void au1xmmc_set_clock(struct au1xmmc_host *host, int rate)
{
        unsigned int pbus = clk_get_rate(host->clk);
        unsigned int divisor = ((pbus / rate) / 2) - 1;
        u32 config;

        config = __raw_readl(HOST_CONFIG(host));

        config &= ~(SD_CONFIG_DIV);
        config |= (divisor & SD_CONFIG_DIV) | SD_CONFIG_DE;

        __raw_writel(config, HOST_CONFIG(host));
        wmb(); /* drain writebuffer */
}

static int au1xmmc_prepare_data(struct au1xmmc_host *host,
                                struct mmc_data *data)
{
        int datalen = data->blocks * data->blksz;

        if (data->flags & MMC_DATA_READ)
                host->flags |= HOST_F_RECV;
        else
                host->flags |= HOST_F_XMIT;

        if (host->mrq->stop)
                host->flags |= HOST_F_STOP;

        host->dma.dir = DMA_BIDIRECTIONAL;

        host->dma.len = dma_map_sg(mmc_dev(host->mmc), data->sg,
                                   data->sg_len, host->dma.dir);

        if (host->dma.len == 0)
                return -ETIMEDOUT;

        __raw_writel(data->blksz - 1, HOST_BLKSIZE(host));

        if (host->flags & (HOST_F_DMA | HOST_F_DBDMA)) {
                int i;
                u32 channel = DMA_CHANNEL(host);

                au1xxx_dbdma_stop(channel);

                for (i = 0; i < host->dma.len; i++) {
                        u32 ret = 0, flags = DDMA_FLAGS_NOIE;
                        struct scatterlist *sg = &data->sg[i];
                        int sg_len = sg->length;

                        int len = (datalen > sg_len) ? sg_len : datalen;

                        if (i == host->dma.len - 1)
                                flags = DDMA_FLAGS_IE;

                        if (host->flags & HOST_F_XMIT) {
                                ret = au1xxx_dbdma_put_source(channel,
                                        sg_phys(sg), len, flags);
                        } else {
                                ret = au1xxx_dbdma_put_dest(channel,
                                        sg_phys(sg), len, flags);
                        }

                        if (!ret)
                                goto dataerr;

                        datalen -= len;
                }
        } else {
                host->pio.index = 0;
                host->pio.offset = 0;
                host->pio.len = datalen;

                if (host->flags & HOST_F_XMIT)
                        IRQ_ON(host, SD_CONFIG_TH);
                else
                        IRQ_ON(host, SD_CONFIG_NE);
                        /* IRQ_ON(host, SD_CONFIG_RA | SD_CONFIG_RF); */
        }

        return 0;

dataerr:
        dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
                        host->dma.dir);
        return -ETIMEDOUT;
}

/* This actually starts a command or data transaction */
static void au1xmmc_request(struct mmc_host* mmc, struct mmc_request* mrq)
{
        struct au1xmmc_host *host = mmc_priv(mmc);
        int ret = 0;

        WARN_ON(irqs_disabled());
        WARN_ON(host->status != HOST_S_IDLE);

        host->mrq = mrq;
        host->status = HOST_S_CMD;

        /* fail request immediately if no card is present */
        if (0 == au1xmmc_card_inserted(mmc)) {
                mrq->cmd->error = -ENOMEDIUM;
                au1xmmc_finish_request(host);
                return;
        }

        if (mrq->data) {
                FLUSH_FIFO(host);
                ret = au1xmmc_prepare_data(host, mrq->data);
        }

        if (!ret)
                ret = au1xmmc_send_command(host, mrq->cmd, mrq->data);

        if (ret) {
                mrq->cmd->error = ret;
                au1xmmc_finish_request(host);
        }
}

static void au1xmmc_reset_controller(struct au1xmmc_host *host)
{
        /* Apply the clock */
        __raw_writel(SD_ENABLE_CE, HOST_ENABLE(host));
        wmb(); /* drain writebuffer */
        mdelay(1);

        __raw_writel(SD_ENABLE_R | SD_ENABLE_CE, HOST_ENABLE(host));
        wmb(); /* drain writebuffer */
        mdelay(5);

        __raw_writel(~0, HOST_STATUS(host));
        wmb(); /* drain writebuffer */

        __raw_writel(0, HOST_BLKSIZE(host));
        __raw_writel(0x001fffff, HOST_TIMEOUT(host));
        wmb(); /* drain writebuffer */

        __raw_writel(SD_CONFIG2_EN, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */

        __raw_writel(SD_CONFIG2_EN | SD_CONFIG2_FF, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */
        mdelay(1);

        __raw_writel(SD_CONFIG2_EN, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */

        /* Configure interrupts */
        __raw_writel(AU1XMMC_INTERRUPTS, HOST_CONFIG(host));
        wmb(); /* drain writebuffer */
}


static void au1xmmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct au1xmmc_host *host = mmc_priv(mmc);
        u32 config2;

        if (ios->power_mode == MMC_POWER_OFF)
                au1xmmc_set_power(host, 0);
        else if (ios->power_mode == MMC_POWER_ON) {
                au1xmmc_set_power(host, 1);
        }

        if (ios->clock && ios->clock != host->clock) {
                au1xmmc_set_clock(host, ios->clock);
                host->clock = ios->clock;
        }

        config2 = __raw_readl(HOST_CONFIG2(host));
        switch (ios->bus_width) {
        case MMC_BUS_WIDTH_8:
                config2 |= SD_CONFIG2_BB;
                break;
        case MMC_BUS_WIDTH_4:
                config2 &= ~SD_CONFIG2_BB;
                config2 |= SD_CONFIG2_WB;
                break;
        case MMC_BUS_WIDTH_1:
                config2 &= ~(SD_CONFIG2_WB | SD_CONFIG2_BB);
                break;
        }
        __raw_writel(config2, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */
}

#define STATUS_TIMEOUT (SD_STATUS_RAT | SD_STATUS_DT)
#define STATUS_DATA_IN  (SD_STATUS_NE)
#define STATUS_DATA_OUT (SD_STATUS_TH)

static irqreturn_t au1xmmc_irq(int irq, void *dev_id)
{
        struct au1xmmc_host *host = dev_id;
        u32 status;

        status = __raw_readl(HOST_STATUS(host));

        if (!(status & SD_STATUS_I))
                return IRQ_NONE;        /* not ours */

        if (status & SD_STATUS_SI)      /* SDIO */
                mmc_signal_sdio_irq(host->mmc);

        if (host->mrq && (status & STATUS_TIMEOUT)) {
                if (status & SD_STATUS_RAT)
                        host->mrq->cmd->error = -ETIMEDOUT;
                else if (status & SD_STATUS_DT)
                        host->mrq->data->error = -ETIMEDOUT;

                /* In PIO mode, interrupts might still be enabled */
                IRQ_OFF(host, SD_CONFIG_NE | SD_CONFIG_TH);

                /* IRQ_OFF(host, SD_CONFIG_TH | SD_CONFIG_RA | SD_CONFIG_RF); */
                queue_work(system_bh_wq, &host->finish_bh_work);
        }
#if 0
        else if (status & SD_STATUS_DD) {
                /* Sometimes we get a DD before a NE in PIO mode */
                if (!(host->flags & HOST_F_DMA) && (status & SD_STATUS_NE))
                        au1xmmc_receive_pio(host);
                else {
                        au1xmmc_data_complete(host, status);
                        /* queue_work(system_bh_wq, &host->data_bh_work); */
                }
        }
#endif
        else if (status & SD_STATUS_CR) {
                if (host->status == HOST_S_CMD)
                        au1xmmc_cmd_complete(host, status);

        } else if (!(host->flags & HOST_F_DMA)) {
                if ((host->flags & HOST_F_XMIT) && (status & STATUS_DATA_OUT))
                        au1xmmc_send_pio(host);
                else if ((host->flags & HOST_F_RECV) && (status & STATUS_DATA_IN))
                        au1xmmc_receive_pio(host);

        } else if (status & 0x203F3C70) {
                        DBG("Unhandled status %8.8x\n", host->pdev->id,
                                status);
        }

        __raw_writel(status, HOST_STATUS(host));
        wmb(); /* drain writebuffer */

        return IRQ_HANDLED;
}

/* 8bit memory DMA device */
static dbdev_tab_t au1xmmc_mem_dbdev = {
        .dev_id         = DSCR_CMD0_ALWAYS,
        .dev_flags      = DEV_FLAGS_ANYUSE,
        .dev_tsize      = 0,
        .dev_devwidth   = 8,
        .dev_physaddr   = 0x00000000,
        .dev_intlevel   = 0,
        .dev_intpolarity = 0,
};
static int memid;

static void au1xmmc_dbdma_callback(int irq, void *dev_id)
{
        struct au1xmmc_host *host = (struct au1xmmc_host *)dev_id;

        /* Avoid spurious interrupts */
        if (!host->mrq)
                return;

        if (host->flags & HOST_F_STOP)
                SEND_STOP(host);

        queue_work(system_bh_wq, &host->data_bh_work);
}

static int au1xmmc_dbdma_init(struct au1xmmc_host *host)
{
        struct resource *res;
        int txid, rxid;

        res = platform_get_resource(host->pdev, IORESOURCE_DMA, 0);
        if (!res)
                return -ENODEV;
        txid = res->start;

        res = platform_get_resource(host->pdev, IORESOURCE_DMA, 1);
        if (!res)
                return -ENODEV;
        rxid = res->start;

        if (!memid)
                return -ENODEV;

        host->tx_chan = au1xxx_dbdma_chan_alloc(memid, txid,
                                au1xmmc_dbdma_callback, (void *)host);
        if (!host->tx_chan) {
                dev_err(&host->pdev->dev, "cannot allocate TX DMA\n");
                return -ENODEV;
        }

        host->rx_chan = au1xxx_dbdma_chan_alloc(rxid, memid,
                                au1xmmc_dbdma_callback, (void *)host);
        if (!host->rx_chan) {
                dev_err(&host->pdev->dev, "cannot allocate RX DMA\n");
                au1xxx_dbdma_chan_free(host->tx_chan);
                return -ENODEV;
        }

        au1xxx_dbdma_set_devwidth(host->tx_chan, 8);
        au1xxx_dbdma_set_devwidth(host->rx_chan, 8);

        au1xxx_dbdma_ring_alloc(host->tx_chan, AU1XMMC_DESCRIPTOR_COUNT);
        au1xxx_dbdma_ring_alloc(host->rx_chan, AU1XMMC_DESCRIPTOR_COUNT);

        /* DBDMA is good to go */
        host->flags |= HOST_F_DMA | HOST_F_DBDMA;

        return 0;
}

static void au1xmmc_dbdma_shutdown(struct au1xmmc_host *host)
{
        if (host->flags & HOST_F_DMA) {
                host->flags &= ~HOST_F_DMA;
                au1xxx_dbdma_chan_free(host->tx_chan);
                au1xxx_dbdma_chan_free(host->rx_chan);
        }
}

static void au1xmmc_enable_sdio_irq(struct mmc_host *mmc, int en)
{
        struct au1xmmc_host *host = mmc_priv(mmc);

        if (en)
                IRQ_ON(host, SD_CONFIG_SI);
        else
                IRQ_OFF(host, SD_CONFIG_SI);
}

static const struct mmc_host_ops au1xmmc_ops = {
        .request        = au1xmmc_request,
        .set_ios        = au1xmmc_set_ios,
        .get_ro         = au1xmmc_card_readonly,
        .get_cd         = au1xmmc_card_inserted,
        .enable_sdio_irq = au1xmmc_enable_sdio_irq,
};

static int au1xmmc_probe(struct platform_device *pdev)
{
        struct mmc_host *mmc;
        struct au1xmmc_host *host;
        struct resource *r;
        int ret, iflag;

        mmc = devm_mmc_alloc_host(&pdev->dev, sizeof(*host));
        if (!mmc) {
                dev_err(&pdev->dev, "no memory for mmc_host\n");
                return -ENOMEM;
        }

        host = mmc_priv(mmc);
        host->mmc = mmc;
        host->platdata = pdev->dev.platform_data;
        host->pdev = pdev;

        ret = -ENODEV;
        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!r) {
                dev_err(&pdev->dev, "no mmio defined\n");
                return ret;
        }

        host->ioarea = request_mem_region(r->start, resource_size(r),
                                           pdev->name);
        if (!host->ioarea) {
                dev_err(&pdev->dev, "mmio already in use\n");
                return ret;
        }

        host->iobase = ioremap(r->start, 0x3c);
        if (!host->iobase) {
                dev_err(&pdev->dev, "cannot remap mmio\n");
                goto out2;
        }

        host->irq = platform_get_irq(pdev, 0);
        if (host->irq < 0) {
                ret = host->irq;
                goto out3;
        }

        mmc->ops = &au1xmmc_ops;

        mmc->f_min =   450000;
        mmc->f_max = 24000000;

        mmc->max_blk_size = 2048;
        mmc->max_blk_count = 512;

        mmc->ocr_avail = AU1XMMC_OCR;
        mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
        mmc->max_segs = AU1XMMC_DESCRIPTOR_COUNT;

        iflag = IRQF_SHARED;    /* Au1100/Au1200: one int for both ctrls */

        switch (alchemy_get_cputype()) {
        case ALCHEMY_CPU_AU1100:
                mmc->max_seg_size = AU1100_MMC_DESCRIPTOR_SIZE;
                break;
        case ALCHEMY_CPU_AU1200:
                mmc->max_seg_size = AU1200_MMC_DESCRIPTOR_SIZE;
                break;
        case ALCHEMY_CPU_AU1300:
                iflag = 0;      /* nothing is shared */
                mmc->max_seg_size = AU1200_MMC_DESCRIPTOR_SIZE;
                mmc->f_max = 52000000;
                if (host->ioarea->start == AU1100_SD0_PHYS_ADDR)
                        mmc->caps |= MMC_CAP_8_BIT_DATA;
                break;
        }

        ret = request_irq(host->irq, au1xmmc_irq, iflag, DRIVER_NAME, host);
        if (ret) {
                dev_err(&pdev->dev, "cannot grab IRQ\n");
                goto out3;
        }

        host->clk = clk_get(&pdev->dev, ALCHEMY_PERIPH_CLK);
        if (IS_ERR(host->clk)) {
                dev_err(&pdev->dev, "cannot find clock\n");
                ret = PTR_ERR(host->clk);
                goto out_irq;
        }

        ret = clk_prepare_enable(host->clk);
        if (ret) {
                dev_err(&pdev->dev, "cannot enable clock\n");
                goto out_clk;
        }

        host->status = HOST_S_IDLE;

        /* board-specific carddetect setup, if any */
        if (host->platdata && host->platdata->cd_setup) {
                ret = host->platdata->cd_setup(mmc, 1);
                if (ret) {
                        dev_warn(&pdev->dev, "board CD setup failed\n");
                        mmc->caps |= MMC_CAP_NEEDS_POLL;
                }
        } else
                mmc->caps |= MMC_CAP_NEEDS_POLL;

        /* platform may not be able to use all advertised caps */
        if (host->platdata)
                mmc->caps &= ~(host->platdata->mask_host_caps);

        INIT_WORK(&host->data_bh_work, au1xmmc_data_bh_work);

        INIT_WORK(&host->finish_bh_work, au1xmmc_finish_bh_work);

        if (has_dbdma()) {
                ret = au1xmmc_dbdma_init(host);
                if (ret)
                        pr_info(DRIVER_NAME ": DBDMA init failed; using PIO\n");
        }

#ifdef CONFIG_LEDS_CLASS
        if (host->platdata && host->platdata->led) {
                struct led_classdev *led = host->platdata->led;
                led->name = mmc_hostname(mmc);
                led->brightness = LED_OFF;
                led->default_trigger = mmc_hostname(mmc);
                ret = led_classdev_register(mmc_dev(mmc), led);
                if (ret)
                        goto out5;
        }
#endif

        au1xmmc_reset_controller(host);

        ret = mmc_add_host(mmc);
        if (ret) {
                dev_err(&pdev->dev, "cannot add mmc host\n");
                goto out6;
        }

        platform_set_drvdata(pdev, host);

        pr_info(DRIVER_NAME ": MMC Controller %d set up at %p"
                " (mode=%s)\n", pdev->id, host->iobase,
                host->flags & HOST_F_DMA ? "dma" : "pio");

        return 0;       /* all ok */

out6:
#ifdef CONFIG_LEDS_CLASS
        if (host->platdata && host->platdata->led)
                led_classdev_unregister(host->platdata->led);
out5:
#endif
        __raw_writel(0, HOST_ENABLE(host));
        __raw_writel(0, HOST_CONFIG(host));
        __raw_writel(0, HOST_CONFIG2(host));
        wmb(); /* drain writebuffer */

        if (host->flags & HOST_F_DBDMA)
                au1xmmc_dbdma_shutdown(host);

        cancel_work_sync(&host->data_bh_work);
        cancel_work_sync(&host->finish_bh_work);

        if (host->platdata && host->platdata->cd_setup &&
            !(mmc->caps & MMC_CAP_NEEDS_POLL))
                host->platdata->cd_setup(mmc, 0);

        clk_disable_unprepare(host->clk);
out_clk:
        clk_put(host->clk);
out_irq:
        free_irq(host->irq, host);
out3:
        iounmap((void *)host->iobase);
out2:
        release_resource(host->ioarea);
        kfree(host->ioarea);
        return ret;
}

static void au1xmmc_remove(struct platform_device *pdev)
{
        struct au1xmmc_host *host = platform_get_drvdata(pdev);

        if (host) {
                mmc_remove_host(host->mmc);

#ifdef CONFIG_LEDS_CLASS
                if (host->platdata && host->platdata->led)
                        led_classdev_unregister(host->platdata->led);
#endif

                if (host->platdata && host->platdata->cd_setup &&
                    !(host->mmc->caps & MMC_CAP_NEEDS_POLL))
                        host->platdata->cd_setup(host->mmc, 0);

                __raw_writel(0, HOST_ENABLE(host));
                __raw_writel(0, HOST_CONFIG(host));
                __raw_writel(0, HOST_CONFIG2(host));
                wmb(); /* drain writebuffer */

                cancel_work_sync(&host->data_bh_work);
                cancel_work_sync(&host->finish_bh_work);

                if (host->flags & HOST_F_DBDMA)
                        au1xmmc_dbdma_shutdown(host);

                au1xmmc_set_power(host, 0);

                clk_disable_unprepare(host->clk);
                clk_put(host->clk);

                free_irq(host->irq, host);
                iounmap((void *)host->iobase);
                release_resource(host->ioarea);
                kfree(host->ioarea);
        }
}

static int au1xmmc_suspend(struct device *dev)
{
        struct au1xmmc_host *host = dev_get_drvdata(dev);

        __raw_writel(0, HOST_CONFIG2(host));
        __raw_writel(0, HOST_CONFIG(host));
        __raw_writel(0xffffffff, HOST_STATUS(host));
        __raw_writel(0, HOST_ENABLE(host));
        wmb(); /* drain writebuffer */

        return 0;
}

static int au1xmmc_resume(struct device *dev)
{
        struct au1xmmc_host *host = dev_get_drvdata(dev);

        au1xmmc_reset_controller(host);

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(au1xmmc_pmops, au1xmmc_suspend, au1xmmc_resume);

static struct platform_driver au1xmmc_driver = {
        .probe         = au1xmmc_probe,
        .remove        = au1xmmc_remove,
        .driver        = {
                .name  = DRIVER_NAME,
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .pm = pm_sleep_ptr(&au1xmmc_pmops),
        },
};

static int __init au1xmmc_init(void)
{
        if (has_dbdma()) {
                /* DSCR_CMD0_ALWAYS has a stride of 32 bits, we need a stride
                * of 8 bits.  And since devices are shared, we need to create
                * our own to avoid freaking out other devices.
                */
                memid = au1xxx_ddma_add_device(&au1xmmc_mem_dbdev);
                if (!memid)
                        pr_err("au1xmmc: cannot add memory dbdma\n");
        }
        return platform_driver_register(&au1xmmc_driver);
}

static void __exit au1xmmc_exit(void)
{
        if (has_dbdma() && memid)
                au1xxx_ddma_del_device(memid);

        platform_driver_unregister(&au1xmmc_driver);
}

module_init(au1xmmc_init);
module_exit(au1xmmc_exit);

MODULE_AUTHOR("Advanced Micro Devices, Inc");
MODULE_DESCRIPTION("MMC/SD driver for the Alchemy Au1XXX");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:au1xxx-mmc");