Merge branches 'for-4.11/upstream-fixes', 'for-4.12/accutouch', 'for-4.12/cp2112...

[mirror_ubuntu-artful-kernel.git] / drivers / mmc / host / mxs-mmc.c

/*
 * Portions copyright (C) 2003 Russell King, PXA MMCI Driver
 * Portions copyright (C) 2004-2005 Pierre Ossman, W83L51xD SD/MMC driver
 *
 * Copyright 2008 Embedded Alley Solutions, Inc.
 * Copyright 2009-2011 Freescale Semiconductor, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/highmem.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/completion.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#include <linux/stmp_device.h>
#include <linux/spi/mxs-spi.h>

#define DRIVER_NAME     "mxs-mmc"

#define MXS_MMC_IRQ_BITS        (BM_SSP_CTRL1_SDIO_IRQ          | \
                                 BM_SSP_CTRL1_RESP_ERR_IRQ      | \
                                 BM_SSP_CTRL1_RESP_TIMEOUT_IRQ  | \
                                 BM_SSP_CTRL1_DATA_TIMEOUT_IRQ  | \
                                 BM_SSP_CTRL1_DATA_CRC_IRQ      | \
                                 BM_SSP_CTRL1_FIFO_UNDERRUN_IRQ | \
                                 BM_SSP_CTRL1_RECV_TIMEOUT_IRQ  | \
                                 BM_SSP_CTRL1_FIFO_OVERRUN_IRQ)

/* card detect polling timeout */
#define MXS_MMC_DETECT_TIMEOUT                  (HZ/2)

struct mxs_mmc_host {
        struct mxs_ssp                  ssp;

        struct mmc_host                 *mmc;
        struct mmc_request              *mrq;
        struct mmc_command              *cmd;
        struct mmc_data                 *data;

        unsigned char                   bus_width;
        spinlock_t                      lock;
        int                             sdio_irq_en;
        bool                            broken_cd;
};

static int mxs_mmc_get_cd(struct mmc_host *mmc)
{
        struct mxs_mmc_host *host = mmc_priv(mmc);
        struct mxs_ssp *ssp = &host->ssp;
        int present, ret;

        if (host->broken_cd)
                return -ENOSYS;

        ret = mmc_gpio_get_cd(mmc);
        if (ret >= 0)
                return ret;

        present = mmc->caps & MMC_CAP_NEEDS_POLL ||
                !(readl(ssp->base + HW_SSP_STATUS(ssp)) &
                        BM_SSP_STATUS_CARD_DETECT);

        if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
                present = !present;

        return present;
}

static int mxs_mmc_reset(struct mxs_mmc_host *host)
{
        struct mxs_ssp *ssp = &host->ssp;
        u32 ctrl0, ctrl1;
        int ret;

        ret = stmp_reset_block(ssp->base);
        if (ret)
                return ret;

        ctrl0 = BM_SSP_CTRL0_IGNORE_CRC;
        ctrl1 = BF_SSP(0x3, CTRL1_SSP_MODE) |
                BF_SSP(0x7, CTRL1_WORD_LENGTH) |
                BM_SSP_CTRL1_DMA_ENABLE |
                BM_SSP_CTRL1_POLARITY |
                BM_SSP_CTRL1_RECV_TIMEOUT_IRQ_EN |
                BM_SSP_CTRL1_DATA_CRC_IRQ_EN |
                BM_SSP_CTRL1_DATA_TIMEOUT_IRQ_EN |
                BM_SSP_CTRL1_RESP_TIMEOUT_IRQ_EN |
                BM_SSP_CTRL1_RESP_ERR_IRQ_EN;

        writel(BF_SSP(0xffff, TIMING_TIMEOUT) |
               BF_SSP(2, TIMING_CLOCK_DIVIDE) |
               BF_SSP(0, TIMING_CLOCK_RATE),
               ssp->base + HW_SSP_TIMING(ssp));

        if (host->sdio_irq_en) {
                ctrl0 |= BM_SSP_CTRL0_SDIO_IRQ_CHECK;
                ctrl1 |= BM_SSP_CTRL1_SDIO_IRQ_EN;
        }

        writel(ctrl0, ssp->base + HW_SSP_CTRL0);
        writel(ctrl1, ssp->base + HW_SSP_CTRL1(ssp));
        return 0;
}

static void mxs_mmc_start_cmd(struct mxs_mmc_host *host,
                              struct mmc_command *cmd);

static void mxs_mmc_request_done(struct mxs_mmc_host *host)
{
        struct mmc_command *cmd = host->cmd;
        struct mmc_data *data = host->data;
        struct mmc_request *mrq = host->mrq;
        struct mxs_ssp *ssp = &host->ssp;

        if (mmc_resp_type(cmd) & MMC_RSP_PRESENT) {
                if (mmc_resp_type(cmd) & MMC_RSP_136) {
                        cmd->resp[3] = readl(ssp->base + HW_SSP_SDRESP0(ssp));
                        cmd->resp[2] = readl(ssp->base + HW_SSP_SDRESP1(ssp));
                        cmd->resp[1] = readl(ssp->base + HW_SSP_SDRESP2(ssp));
                        cmd->resp[0] = readl(ssp->base + HW_SSP_SDRESP3(ssp));
                } else {
                        cmd->resp[0] = readl(ssp->base + HW_SSP_SDRESP0(ssp));
                }
        }

        if (cmd == mrq->sbc) {
                /* Finished CMD23, now send actual command. */
                mxs_mmc_start_cmd(host, mrq->cmd);
                return;
        } else if (data) {
                dma_unmap_sg(mmc_dev(host->mmc), data->sg,
                             data->sg_len, ssp->dma_dir);
                /*
                 * If there was an error on any block, we mark all
                 * data blocks as being in error.
                 */
                if (!data->error)
                        data->bytes_xfered = data->blocks * data->blksz;
                else
                        data->bytes_xfered = 0;

                host->data = NULL;
                if (data->stop && (data->error || !mrq->sbc)) {
                        mxs_mmc_start_cmd(host, mrq->stop);
                        return;
                }
        }

        host->mrq = NULL;
        mmc_request_done(host->mmc, mrq);
}

static void mxs_mmc_dma_irq_callback(void *param)
{
        struct mxs_mmc_host *host = param;

        mxs_mmc_request_done(host);
}

static irqreturn_t mxs_mmc_irq_handler(int irq, void *dev_id)
{
        struct mxs_mmc_host *host = dev_id;
        struct mmc_command *cmd = host->cmd;
        struct mmc_data *data = host->data;
        struct mxs_ssp *ssp = &host->ssp;
        u32 stat;

        spin_lock(&host->lock);

        stat = readl(ssp->base + HW_SSP_CTRL1(ssp));
        writel(stat & MXS_MMC_IRQ_BITS,
               ssp->base + HW_SSP_CTRL1(ssp) + STMP_OFFSET_REG_CLR);

        spin_unlock(&host->lock);

        if ((stat & BM_SSP_CTRL1_SDIO_IRQ) && (stat & BM_SSP_CTRL1_SDIO_IRQ_EN))
                mmc_signal_sdio_irq(host->mmc);

        if (stat & BM_SSP_CTRL1_RESP_TIMEOUT_IRQ)
                cmd->error = -ETIMEDOUT;
        else if (stat & BM_SSP_CTRL1_RESP_ERR_IRQ)
                cmd->error = -EIO;

        if (data) {
                if (stat & (BM_SSP_CTRL1_DATA_TIMEOUT_IRQ |
                            BM_SSP_CTRL1_RECV_TIMEOUT_IRQ))
                        data->error = -ETIMEDOUT;
                else if (stat & BM_SSP_CTRL1_DATA_CRC_IRQ)
                        data->error = -EILSEQ;
                else if (stat & (BM_SSP_CTRL1_FIFO_UNDERRUN_IRQ |
                                 BM_SSP_CTRL1_FIFO_OVERRUN_IRQ))
                        data->error = -EIO;
        }

        return IRQ_HANDLED;
}

static struct dma_async_tx_descriptor *mxs_mmc_prep_dma(
        struct mxs_mmc_host *host, unsigned long flags)
{
        struct mxs_ssp *ssp = &host->ssp;
        struct dma_async_tx_descriptor *desc;
        struct mmc_data *data = host->data;
        struct scatterlist * sgl;
        unsigned int sg_len;

        if (data) {
                /* data */
                dma_map_sg(mmc_dev(host->mmc), data->sg,
                           data->sg_len, ssp->dma_dir);
                sgl = data->sg;
                sg_len = data->sg_len;
        } else {
                /* pio */
                sgl = (struct scatterlist *) ssp->ssp_pio_words;
                sg_len = SSP_PIO_NUM;
        }

        desc = dmaengine_prep_slave_sg(ssp->dmach,
                                sgl, sg_len, ssp->slave_dirn, flags);
        if (desc) {
                desc->callback = mxs_mmc_dma_irq_callback;
                desc->callback_param = host;
        } else {
                if (data)
                        dma_unmap_sg(mmc_dev(host->mmc), data->sg,
                                     data->sg_len, ssp->dma_dir);
        }

        return desc;
}

static void mxs_mmc_bc(struct mxs_mmc_host *host)
{
        struct mxs_ssp *ssp = &host->ssp;
        struct mmc_command *cmd = host->cmd;
        struct dma_async_tx_descriptor *desc;
        u32 ctrl0, cmd0, cmd1;

        ctrl0 = BM_SSP_CTRL0_ENABLE | BM_SSP_CTRL0_IGNORE_CRC;
        cmd0 = BF_SSP(cmd->opcode, CMD0_CMD) | BM_SSP_CMD0_APPEND_8CYC;
        cmd1 = cmd->arg;

        if (host->sdio_irq_en) {
                ctrl0 |= BM_SSP_CTRL0_SDIO_IRQ_CHECK;
                cmd0 |= BM_SSP_CMD0_CONT_CLKING_EN | BM_SSP_CMD0_SLOW_CLKING_EN;
        }

        ssp->ssp_pio_words[0] = ctrl0;
        ssp->ssp_pio_words[1] = cmd0;
        ssp->ssp_pio_words[2] = cmd1;
        ssp->dma_dir = DMA_NONE;
        ssp->slave_dirn = DMA_TRANS_NONE;
        desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK);
        if (!desc)
                goto out;

        dmaengine_submit(desc);
        dma_async_issue_pending(ssp->dmach);
        return;

out:
        dev_warn(mmc_dev(host->mmc),
                 "%s: failed to prep dma\n", __func__);
}

static void mxs_mmc_ac(struct mxs_mmc_host *host)
{
        struct mxs_ssp *ssp = &host->ssp;
        struct mmc_command *cmd = host->cmd;
        struct dma_async_tx_descriptor *desc;
        u32 ignore_crc, get_resp, long_resp;
        u32 ctrl0, cmd0, cmd1;

        ignore_crc = (mmc_resp_type(cmd) & MMC_RSP_CRC) ?
                        0 : BM_SSP_CTRL0_IGNORE_CRC;
        get_resp = (mmc_resp_type(cmd) & MMC_RSP_PRESENT) ?
                        BM_SSP_CTRL0_GET_RESP : 0;
        long_resp = (mmc_resp_type(cmd) & MMC_RSP_136) ?
                        BM_SSP_CTRL0_LONG_RESP : 0;

        ctrl0 = BM_SSP_CTRL0_ENABLE | ignore_crc | get_resp | long_resp;
        cmd0 = BF_SSP(cmd->opcode, CMD0_CMD);
        cmd1 = cmd->arg;

        if (cmd->opcode == MMC_STOP_TRANSMISSION)
                cmd0 |= BM_SSP_CMD0_APPEND_8CYC;

        if (host->sdio_irq_en) {
                ctrl0 |= BM_SSP_CTRL0_SDIO_IRQ_CHECK;
                cmd0 |= BM_SSP_CMD0_CONT_CLKING_EN | BM_SSP_CMD0_SLOW_CLKING_EN;
        }

        ssp->ssp_pio_words[0] = ctrl0;
        ssp->ssp_pio_words[1] = cmd0;
        ssp->ssp_pio_words[2] = cmd1;
        ssp->dma_dir = DMA_NONE;
        ssp->slave_dirn = DMA_TRANS_NONE;
        desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK);
        if (!desc)
                goto out;

        dmaengine_submit(desc);
        dma_async_issue_pending(ssp->dmach);
        return;

out:
        dev_warn(mmc_dev(host->mmc),
                 "%s: failed to prep dma\n", __func__);
}

static unsigned short mxs_ns_to_ssp_ticks(unsigned clock_rate, unsigned ns)
{
        const unsigned int ssp_timeout_mul = 4096;
        /*
         * Calculate ticks in ms since ns are large numbers
         * and might overflow
         */
        const unsigned int clock_per_ms = clock_rate / 1000;
        const unsigned int ms = ns / 1000;
        const unsigned int ticks = ms * clock_per_ms;
        const unsigned int ssp_ticks = ticks / ssp_timeout_mul;

        WARN_ON(ssp_ticks == 0);
        return ssp_ticks;
}

static void mxs_mmc_adtc(struct mxs_mmc_host *host)
{
        struct mmc_command *cmd = host->cmd;
        struct mmc_data *data = cmd->data;
        struct dma_async_tx_descriptor *desc;
        struct scatterlist *sgl = data->sg, *sg;
        unsigned int sg_len = data->sg_len;
        unsigned int i;

        unsigned short dma_data_dir, timeout;
        enum dma_transfer_direction slave_dirn;
        unsigned int data_size = 0, log2_blksz;
        unsigned int blocks = data->blocks;

        struct mxs_ssp *ssp = &host->ssp;

        u32 ignore_crc, get_resp, long_resp, read;
        u32 ctrl0, cmd0, cmd1, val;

        ignore_crc = (mmc_resp_type(cmd) & MMC_RSP_CRC) ?
                        0 : BM_SSP_CTRL0_IGNORE_CRC;
        get_resp = (mmc_resp_type(cmd) & MMC_RSP_PRESENT) ?
                        BM_SSP_CTRL0_GET_RESP : 0;
        long_resp = (mmc_resp_type(cmd) & MMC_RSP_136) ?
                        BM_SSP_CTRL0_LONG_RESP : 0;

        if (data->flags & MMC_DATA_WRITE) {
                dma_data_dir = DMA_TO_DEVICE;
                slave_dirn = DMA_MEM_TO_DEV;
                read = 0;
        } else {
                dma_data_dir = DMA_FROM_DEVICE;
                slave_dirn = DMA_DEV_TO_MEM;
                read = BM_SSP_CTRL0_READ;
        }

        ctrl0 = BF_SSP(host->bus_width, CTRL0_BUS_WIDTH) |
                ignore_crc | get_resp | long_resp |
                BM_SSP_CTRL0_DATA_XFER | read |
                BM_SSP_CTRL0_WAIT_FOR_IRQ |
                BM_SSP_CTRL0_ENABLE;

        cmd0 = BF_SSP(cmd->opcode, CMD0_CMD);

        /* get logarithm to base 2 of block size for setting register */
        log2_blksz = ilog2(data->blksz);

        /*
         * take special care of the case that data size from data->sg
         * is not equal to blocks x blksz
         */
        for_each_sg(sgl, sg, sg_len, i)
                data_size += sg->length;

        if (data_size != data->blocks * data->blksz)
                blocks = 1;

        /* xfer count, block size and count need to be set differently */
        if (ssp_is_old(ssp)) {
                ctrl0 |= BF_SSP(data_size, CTRL0_XFER_COUNT);
                cmd0 |= BF_SSP(log2_blksz, CMD0_BLOCK_SIZE) |
                        BF_SSP(blocks - 1, CMD0_BLOCK_COUNT);
        } else {
                writel(data_size, ssp->base + HW_SSP_XFER_SIZE);
                writel(BF_SSP(log2_blksz, BLOCK_SIZE_BLOCK_SIZE) |
                       BF_SSP(blocks - 1, BLOCK_SIZE_BLOCK_COUNT),
                       ssp->base + HW_SSP_BLOCK_SIZE);
        }

        if (cmd->opcode == SD_IO_RW_EXTENDED)
                cmd0 |= BM_SSP_CMD0_APPEND_8CYC;

        cmd1 = cmd->arg;

        if (host->sdio_irq_en) {
                ctrl0 |= BM_SSP_CTRL0_SDIO_IRQ_CHECK;
                cmd0 |= BM_SSP_CMD0_CONT_CLKING_EN | BM_SSP_CMD0_SLOW_CLKING_EN;
        }

        /* set the timeout count */
        timeout = mxs_ns_to_ssp_ticks(ssp->clk_rate, data->timeout_ns);
        val = readl(ssp->base + HW_SSP_TIMING(ssp));
        val &= ~(BM_SSP_TIMING_TIMEOUT);
        val |= BF_SSP(timeout, TIMING_TIMEOUT);
        writel(val, ssp->base + HW_SSP_TIMING(ssp));

        /* pio */
        ssp->ssp_pio_words[0] = ctrl0;
        ssp->ssp_pio_words[1] = cmd0;
        ssp->ssp_pio_words[2] = cmd1;
        ssp->dma_dir = DMA_NONE;
        ssp->slave_dirn = DMA_TRANS_NONE;
        desc = mxs_mmc_prep_dma(host, 0);
        if (!desc)
                goto out;

        /* append data sg */
        WARN_ON(host->data != NULL);
        host->data = data;
        ssp->dma_dir = dma_data_dir;
        ssp->slave_dirn = slave_dirn;
        desc = mxs_mmc_prep_dma(host, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!desc)
                goto out;

        dmaengine_submit(desc);
        dma_async_issue_pending(ssp->dmach);
        return;
out:
        dev_warn(mmc_dev(host->mmc),
                 "%s: failed to prep dma\n", __func__);
}

static void mxs_mmc_start_cmd(struct mxs_mmc_host *host,
                              struct mmc_command *cmd)
{
        host->cmd = cmd;

        switch (mmc_cmd_type(cmd)) {
        case MMC_CMD_BC:
                mxs_mmc_bc(host);
                break;
        case MMC_CMD_BCR:
                mxs_mmc_ac(host);
                break;
        case MMC_CMD_AC:
                mxs_mmc_ac(host);
                break;
        case MMC_CMD_ADTC:
                mxs_mmc_adtc(host);
                break;
        default:
                dev_warn(mmc_dev(host->mmc),
                         "%s: unknown MMC command\n", __func__);
                break;
        }
}

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

        WARN_ON(host->mrq != NULL);
        host->mrq = mrq;

        if (mrq->sbc)
                mxs_mmc_start_cmd(host, mrq->sbc);
        else
                mxs_mmc_start_cmd(host, mrq->cmd);
}

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

        if (ios->bus_width == MMC_BUS_WIDTH_8)
                host->bus_width = 2;
        else if (ios->bus_width == MMC_BUS_WIDTH_4)
                host->bus_width = 1;
        else
                host->bus_width = 0;

        if (ios->clock)
                mxs_ssp_set_clk_rate(&host->ssp, ios->clock);
}

static void mxs_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
{
        struct mxs_mmc_host *host = mmc_priv(mmc);
        struct mxs_ssp *ssp = &host->ssp;
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);

        host->sdio_irq_en = enable;

        if (enable) {
                writel(BM_SSP_CTRL0_SDIO_IRQ_CHECK,
                       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_SET);
                writel(BM_SSP_CTRL1_SDIO_IRQ_EN,
                       ssp->base + HW_SSP_CTRL1(ssp) + STMP_OFFSET_REG_SET);
        } else {
                writel(BM_SSP_CTRL0_SDIO_IRQ_CHECK,
                       ssp->base + HW_SSP_CTRL0 + STMP_OFFSET_REG_CLR);
                writel(BM_SSP_CTRL1_SDIO_IRQ_EN,
                       ssp->base + HW_SSP_CTRL1(ssp) + STMP_OFFSET_REG_CLR);
        }

        spin_unlock_irqrestore(&host->lock, flags);

        if (enable && readl(ssp->base + HW_SSP_STATUS(ssp)) &
                        BM_SSP_STATUS_SDIO_IRQ)
                mmc_signal_sdio_irq(host->mmc);

}

static const struct mmc_host_ops mxs_mmc_ops = {
        .request = mxs_mmc_request,
        .get_ro = mmc_gpio_get_ro,
        .get_cd = mxs_mmc_get_cd,
        .set_ios = mxs_mmc_set_ios,
        .enable_sdio_irq = mxs_mmc_enable_sdio_irq,
};

static const struct platform_device_id mxs_ssp_ids[] = {
        {
                .name = "imx23-mmc",
                .driver_data = IMX23_SSP,
        }, {
                .name = "imx28-mmc",
                .driver_data = IMX28_SSP,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, mxs_ssp_ids);

static const struct of_device_id mxs_mmc_dt_ids[] = {
        { .compatible = "fsl,imx23-mmc", .data = (void *) IMX23_SSP, },
        { .compatible = "fsl,imx28-mmc", .data = (void *) IMX28_SSP, },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxs_mmc_dt_ids);

static int mxs_mmc_probe(struct platform_device *pdev)
{
        const struct of_device_id *of_id =
                        of_match_device(mxs_mmc_dt_ids, &pdev->dev);
        struct device_node *np = pdev->dev.of_node;
        struct mxs_mmc_host *host;
        struct mmc_host *mmc;
        struct resource *iores;
        int ret = 0, irq_err;
        struct regulator *reg_vmmc;
        struct mxs_ssp *ssp;

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

        mmc = mmc_alloc_host(sizeof(struct mxs_mmc_host), &pdev->dev);
        if (!mmc)
                return -ENOMEM;

        host = mmc_priv(mmc);
        ssp = &host->ssp;
        ssp->dev = &pdev->dev;
        iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        ssp->base = devm_ioremap_resource(&pdev->dev, iores);
        if (IS_ERR(ssp->base)) {
                ret = PTR_ERR(ssp->base);
                goto out_mmc_free;
        }

        ssp->devid = (enum mxs_ssp_id) of_id->data;

        host->mmc = mmc;
        host->sdio_irq_en = 0;

        reg_vmmc = devm_regulator_get(&pdev->dev, "vmmc");
        if (!IS_ERR(reg_vmmc)) {
                ret = regulator_enable(reg_vmmc);
                if (ret) {
                        dev_err(&pdev->dev,
                                "Failed to enable vmmc regulator: %d\n", ret);
                        goto out_mmc_free;
                }
        }

        ssp->clk = devm_clk_get(&pdev->dev, NULL);
        if (IS_ERR(ssp->clk)) {
                ret = PTR_ERR(ssp->clk);
                goto out_mmc_free;
        }
        ret = clk_prepare_enable(ssp->clk);
        if (ret)
                goto out_mmc_free;

        ret = mxs_mmc_reset(host);
        if (ret) {
                dev_err(&pdev->dev, "Failed to reset mmc: %d\n", ret);
                goto out_clk_disable;
        }

        ssp->dmach = dma_request_slave_channel(&pdev->dev, "rx-tx");
        if (!ssp->dmach) {
                dev_err(mmc_dev(host->mmc),
                        "%s: failed to request dma\n", __func__);
                ret = -ENODEV;
                goto out_clk_disable;
        }

        /* set mmc core parameters */
        mmc->ops = &mxs_mmc_ops;
        mmc->caps = MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
                    MMC_CAP_SDIO_IRQ | MMC_CAP_NEEDS_POLL | MMC_CAP_CMD23;

        host->broken_cd = of_property_read_bool(np, "broken-cd");

        mmc->f_min = 400000;
        mmc->f_max = 288000000;

        ret = mmc_of_parse(mmc);
        if (ret)
                goto out_clk_disable;

        mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;

        mmc->max_segs = 52;
        mmc->max_blk_size = 1 << 0xf;
        mmc->max_blk_count = (ssp_is_old(ssp)) ? 0xff : 0xffffff;
        mmc->max_req_size = (ssp_is_old(ssp)) ? 0xffff : 0xffffffff;
        mmc->max_seg_size = dma_get_max_seg_size(ssp->dmach->device->dev);

        platform_set_drvdata(pdev, mmc);

        spin_lock_init(&host->lock);

        ret = devm_request_irq(&pdev->dev, irq_err, mxs_mmc_irq_handler, 0,
                               dev_name(&pdev->dev), host);
        if (ret)
                goto out_free_dma;

        ret = mmc_add_host(mmc);
        if (ret)
                goto out_free_dma;

        dev_info(mmc_dev(host->mmc), "initialized\n");

        return 0;

out_free_dma:
        dma_release_channel(ssp->dmach);
out_clk_disable:
        clk_disable_unprepare(ssp->clk);
out_mmc_free:
        mmc_free_host(mmc);
        return ret;
}

static int mxs_mmc_remove(struct platform_device *pdev)
{
        struct mmc_host *mmc = platform_get_drvdata(pdev);
        struct mxs_mmc_host *host = mmc_priv(mmc);
        struct mxs_ssp *ssp = &host->ssp;

        mmc_remove_host(mmc);

        if (ssp->dmach)
                dma_release_channel(ssp->dmach);

        clk_disable_unprepare(ssp->clk);

        mmc_free_host(mmc);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mxs_mmc_suspend(struct device *dev)
{
        struct mmc_host *mmc = dev_get_drvdata(dev);
        struct mxs_mmc_host *host = mmc_priv(mmc);
        struct mxs_ssp *ssp = &host->ssp;

        clk_disable_unprepare(ssp->clk);
        return 0;
}

static int mxs_mmc_resume(struct device *dev)
{
        struct mmc_host *mmc = dev_get_drvdata(dev);
        struct mxs_mmc_host *host = mmc_priv(mmc);
        struct mxs_ssp *ssp = &host->ssp;

        return clk_prepare_enable(ssp->clk);
}
#endif

static SIMPLE_DEV_PM_OPS(mxs_mmc_pm_ops, mxs_mmc_suspend, mxs_mmc_resume);

static struct platform_driver mxs_mmc_driver = {
        .probe          = mxs_mmc_probe,
        .remove         = mxs_mmc_remove,
        .id_table       = mxs_ssp_ids,
        .driver         = {
                .name   = DRIVER_NAME,
                .pm     = &mxs_mmc_pm_ops,
                .of_match_table = mxs_mmc_dt_ids,
        },
};

module_platform_driver(mxs_mmc_driver);

MODULE_DESCRIPTION("FREESCALE MXS MMC peripheral");
MODULE_AUTHOR("Freescale Semiconductor");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);