/*
 * Freescale eSDHC i.MX controller driver for the platform bus.
 *
 * derived from the OF-version.
 *
 * Copyright (c) 2010 Pengutronix e.K.
 *   Author: Wolfram Sang <w.sang@pengutronix.de>
 *
 * 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.
 */

#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_data/mmc-esdhc-imx.h>
#include "sdhci-pltfm.h"
#include "sdhci-esdhc.h"

#define ESDHC_CTRL_D3CD                 0x08
/* VENDOR SPEC register */
#define ESDHC_VENDOR_SPEC               0xc0
#define  ESDHC_VENDOR_SPEC_SDIO_QUIRK   (1 << 1)
#define ESDHC_WTMK_LVL                  0x44
#define ESDHC_MIX_CTRL                  0x48
#define  ESDHC_MIX_CTRL_AC23EN          (1 << 7)
/* Bits 3 and 6 are not SDHCI standard definitions */
#define  ESDHC_MIX_CTRL_SDHCI_MASK      0xb7

/*
 * Our interpretation of the SDHCI_HOST_CONTROL register
 */
#define ESDHC_CTRL_4BITBUS              (0x1 << 1)
#define ESDHC_CTRL_8BITBUS              (0x2 << 1)
#define ESDHC_CTRL_BUSWIDTH_MASK        (0x3 << 1)

/*
 * There is an INT DMA ERR mis-match between eSDHC and STD SDHC SPEC:
 * Bit25 is used in STD SPEC, and is reserved in fsl eSDHC design,
 * but bit28 is used as the INT DMA ERR in fsl eSDHC design.
 * Define this macro DMA error INT for fsl eSDHC
 */
#define ESDHC_INT_VENDOR_SPEC_DMA_ERR   (1 << 28)

/*
 * The CMDTYPE of the CMD register (offset 0xE) should be set to
 * "11" when the STOP CMD12 is issued on imx53 to abort one
 * open ended multi-blk IO. Otherwise the TC INT wouldn't
 * be generated.
 * In exact block transfer, the controller doesn't complete the
 * operations automatically as required at the end of the
 * transfer and remains on hold if the abort command is not sent.
 * As a result, the TC flag is not asserted and SW  received timeout
 * exeception. Bit1 of Vendor Spec registor is used to fix it.
 */
#define ESDHC_FLAG_MULTIBLK_NO_INT      (1 << 1)

enum imx_esdhc_type {
        IMX25_ESDHC,
        IMX35_ESDHC,
        IMX51_ESDHC,
        IMX53_ESDHC,
        IMX6Q_USDHC,
};

struct pltfm_imx_data {
        int flags;
        u32 scratchpad;
        enum imx_esdhc_type devtype;
        struct pinctrl *pinctrl;
        struct esdhc_platform_data boarddata;
        struct clk *clk_ipg;
        struct clk *clk_ahb;
        struct clk *clk_per;
};

static struct platform_device_id imx_esdhc_devtype[] = {
        {
                .name = "sdhci-esdhc-imx25",
                .driver_data = IMX25_ESDHC,
        }, {
                .name = "sdhci-esdhc-imx35",
                .driver_data = IMX35_ESDHC,
        }, {
                .name = "sdhci-esdhc-imx51",
                .driver_data = IMX51_ESDHC,
        }, {
                .name = "sdhci-esdhc-imx53",
                .driver_data = IMX53_ESDHC,
        }, {
                .name = "sdhci-usdhc-imx6q",
                .driver_data = IMX6Q_USDHC,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, imx_esdhc_devtype);

static const struct of_device_id imx_esdhc_dt_ids[] = {
        { .compatible = "fsl,imx25-esdhc", .data = &imx_esdhc_devtype[IMX25_ESDHC], },
        { .compatible = "fsl,imx35-esdhc", .data = &imx_esdhc_devtype[IMX35_ESDHC], },
        { .compatible = "fsl,imx51-esdhc", .data = &imx_esdhc_devtype[IMX51_ESDHC], },
        { .compatible = "fsl,imx53-esdhc", .data = &imx_esdhc_devtype[IMX53_ESDHC], },
        { .compatible = "fsl,imx6q-usdhc", .data = &imx_esdhc_devtype[IMX6Q_USDHC], },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_esdhc_dt_ids);

static inline int is_imx25_esdhc(struct pltfm_imx_data *data)
{
        return data->devtype == IMX25_ESDHC;
}

static inline int is_imx35_esdhc(struct pltfm_imx_data *data)
{
        return data->devtype == IMX35_ESDHC;
}

static inline int is_imx51_esdhc(struct pltfm_imx_data *data)
{
        return data->devtype == IMX51_ESDHC;
}

static inline int is_imx53_esdhc(struct pltfm_imx_data *data)
{
        return data->devtype == IMX53_ESDHC;
}

static inline int is_imx6q_usdhc(struct pltfm_imx_data *data)
{
        return data->devtype == IMX6Q_USDHC;
}

static inline void esdhc_clrset_le(struct sdhci_host *host, u32 mask, u32 val, int reg)
{
        void __iomem *base = host->ioaddr + (reg & ~0x3);
        u32 shift = (reg & 0x3) * 8;

        writel(((readl(base) & ~(mask << shift)) | (val << shift)), base);
}

static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
{
        u32 val = readl(host->ioaddr + reg);

        if (unlikely(reg == SDHCI_CAPABILITIES)) {
                /* In FSL esdhc IC module, only bit20 is used to indicate the
                 * ADMA2 capability of esdhc, but this bit is messed up on
                 * some SOCs (e.g. on MX25, MX35 this bit is set, but they
                 * don't actually support ADMA2). So set the BROKEN_ADMA
                 * uirk on MX25/35 platforms.
                 */

                if (val & SDHCI_CAN_DO_ADMA1) {
                        val &= ~SDHCI_CAN_DO_ADMA1;
                        val |= SDHCI_CAN_DO_ADMA2;
                }
        }

        if (unlikely(reg == SDHCI_INT_STATUS)) {
                if (val & ESDHC_INT_VENDOR_SPEC_DMA_ERR) {
                        val &= ~ESDHC_INT_VENDOR_SPEC_DMA_ERR;
                        val |= SDHCI_INT_ADMA_ERROR;
                }
        }

        return val;
}

static void esdhc_writel_le(struct sdhci_host *host, u32 val, int reg)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;
        u32 data;

        if (unlikely(reg == SDHCI_INT_ENABLE || reg == SDHCI_SIGNAL_ENABLE)) {
                if (val & SDHCI_INT_CARD_INT) {
                        /*
                         * Clear and then set D3CD bit to avoid missing the
                         * card interrupt.  This is a eSDHC controller problem
                         * so we need to apply the following workaround: clear
                         * and set D3CD bit will make eSDHC re-sample the card
                         * interrupt. In case a card interrupt was lost,
                         * re-sample it by the following steps.
                         */
                        data = readl(host->ioaddr + SDHCI_HOST_CONTROL);
                        data &= ~ESDHC_CTRL_D3CD;
                        writel(data, host->ioaddr + SDHCI_HOST_CONTROL);
                        data |= ESDHC_CTRL_D3CD;
                        writel(data, host->ioaddr + SDHCI_HOST_CONTROL);
                }
        }

        if (unlikely((imx_data->flags & ESDHC_FLAG_MULTIBLK_NO_INT)
                                && (reg == SDHCI_INT_STATUS)
                                && (val & SDHCI_INT_DATA_END))) {
                        u32 v;
                        v = readl(host->ioaddr + ESDHC_VENDOR_SPEC);
                        v &= ~ESDHC_VENDOR_SPEC_SDIO_QUIRK;
                        writel(v, host->ioaddr + ESDHC_VENDOR_SPEC);
        }

        if (unlikely(reg == SDHCI_INT_ENABLE || reg == SDHCI_SIGNAL_ENABLE)) {
                if (val & SDHCI_INT_ADMA_ERROR) {
                        val &= ~SDHCI_INT_ADMA_ERROR;
                        val |= ESDHC_INT_VENDOR_SPEC_DMA_ERR;
                }
        }

        writel(val, host->ioaddr + reg);
}

static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;

        if (unlikely(reg == SDHCI_HOST_VERSION)) {
                reg ^= 2;
                if (is_imx6q_usdhc(imx_data)) {
                        /*
                         * The usdhc register returns a wrong host version.
                         * Correct it here.
                         */
                        return SDHCI_SPEC_300;
                }
        }

        return readw(host->ioaddr + reg);
}

static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;

        switch (reg) {
        case SDHCI_TRANSFER_MODE:
                if ((imx_data->flags & ESDHC_FLAG_MULTIBLK_NO_INT)
                                && (host->cmd->opcode == SD_IO_RW_EXTENDED)
                                && (host->cmd->data->blocks > 1)
                                && (host->cmd->data->flags & MMC_DATA_READ)) {
                        u32 v;
                        v = readl(host->ioaddr + ESDHC_VENDOR_SPEC);
                        v |= ESDHC_VENDOR_SPEC_SDIO_QUIRK;
                        writel(v, host->ioaddr + ESDHC_VENDOR_SPEC);
                }

                if (is_imx6q_usdhc(imx_data)) {
                        u32 m = readl(host->ioaddr + ESDHC_MIX_CTRL);
                        /* Swap AC23 bit */
                        if (val & SDHCI_TRNS_AUTO_CMD23) {
                                val &= ~SDHCI_TRNS_AUTO_CMD23;
                                val |= ESDHC_MIX_CTRL_AC23EN;
                        }
                        m = val | (m & ~ESDHC_MIX_CTRL_SDHCI_MASK);
                        writel(m, host->ioaddr + ESDHC_MIX_CTRL);
                } else {
                        /*
                         * Postpone this write, we must do it together with a
                         * command write that is down below.
                         */
                        imx_data->scratchpad = val;
                }
                return;
        case SDHCI_COMMAND:
                if ((host->cmd->opcode == MMC_STOP_TRANSMISSION ||
                     host->cmd->opcode == MMC_SET_BLOCK_COUNT) &&
                    (imx_data->flags & ESDHC_FLAG_MULTIBLK_NO_INT))
                        val |= SDHCI_CMD_ABORTCMD;

                if (is_imx6q_usdhc(imx_data))
                        writel(val << 16,
                               host->ioaddr + SDHCI_TRANSFER_MODE);
                else
                        writel(val << 16 | imx_data->scratchpad,
                               host->ioaddr + SDHCI_TRANSFER_MODE);
                return;
        case SDHCI_BLOCK_SIZE:
                val &= ~SDHCI_MAKE_BLKSZ(0x7, 0);
                break;
        }
        esdhc_clrset_le(host, 0xffff, val, reg);
}

static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;
        u32 new_val;
        u32 mask;

        switch (reg) {
        case SDHCI_POWER_CONTROL:
                /*
                 * FSL put some DMA bits here
                 * If your board has a regulator, code should be here
                 */
                return;
        case SDHCI_HOST_CONTROL:
                /* FSL messed up here, so we need to manually compose it. */
                new_val = val & SDHCI_CTRL_LED;
                /* ensure the endianness */
                new_val |= ESDHC_HOST_CONTROL_LE;
                /* bits 8&9 are reserved on mx25 */
                if (!is_imx25_esdhc(imx_data)) {
                        /* DMA mode bits are shifted */
                        new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;
                }

                /*
                 * Do not touch buswidth bits here. This is done in
                 * esdhc_pltfm_bus_width.
                 */
                mask = 0xffff & ~ESDHC_CTRL_BUSWIDTH_MASK;

                esdhc_clrset_le(host, mask, new_val, reg);
                return;
        }
        esdhc_clrset_le(host, 0xff, val, reg);

        /*
         * The esdhc has a design violation to SDHC spec which tells
         * that software reset should not affect card detection circuit.
         * But esdhc clears its SYSCTL register bits [0..2] during the
         * software reset.  This will stop those clocks that card detection
         * circuit relies on.  To work around it, we turn the clocks on back
         * to keep card detection circuit functional.
         */
        if ((reg == SDHCI_SOFTWARE_RESET) && (val & 1)) {
                esdhc_clrset_le(host, 0x7, 0x7, ESDHC_SYSTEM_CONTROL);
                /*
                 * The reset on usdhc fails to clear MIX_CTRL register.
                 * Do it manually here.
                 */
                if (is_imx6q_usdhc(imx_data))
                        writel(0, host->ioaddr + ESDHC_MIX_CTRL);
        }
}

static unsigned int esdhc_pltfm_get_min_clock(struct sdhci_host *host)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);

        return clk_get_rate(pltfm_host->clk) / 256 / 16;
}

static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;
        struct esdhc_platform_data *boarddata = &imx_data->boarddata;

        switch (boarddata->wp_type) {
        case ESDHC_WP_GPIO:
                return mmc_gpio_get_ro(host->mmc);
        case ESDHC_WP_CONTROLLER:
                return !(readl(host->ioaddr + SDHCI_PRESENT_STATE) &
                               SDHCI_WRITE_PROTECT);
        case ESDHC_WP_NONE:
                break;
        }

        return -ENOSYS;
}

static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width)
{
        u32 ctrl;

        switch (width) {
        case MMC_BUS_WIDTH_8:
                ctrl = ESDHC_CTRL_8BITBUS;
                break;
        case MMC_BUS_WIDTH_4:
                ctrl = ESDHC_CTRL_4BITBUS;
                break;
        default:
                ctrl = 0;
                break;
        }

        esdhc_clrset_le(host, ESDHC_CTRL_BUSWIDTH_MASK, ctrl,
                        SDHCI_HOST_CONTROL);

        return 0;
}

static struct sdhci_ops sdhci_esdhc_ops = {
        .read_l = esdhc_readl_le,
        .read_w = esdhc_readw_le,
        .write_l = esdhc_writel_le,
        .write_w = esdhc_writew_le,
        .write_b = esdhc_writeb_le,
        .set_clock = esdhc_set_clock,
        .get_max_clock = sdhci_pltfm_clk_get_max_clock,
        .get_min_clock = esdhc_pltfm_get_min_clock,
        .get_ro = esdhc_pltfm_get_ro,
        .platform_bus_width = esdhc_pltfm_bus_width,
};

static struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
        .quirks = ESDHC_DEFAULT_QUIRKS | SDHCI_QUIRK_NO_HISPD_BIT
                        | SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC
                        | SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC
                        | SDHCI_QUIRK_BROKEN_CARD_DETECTION,
        .ops = &sdhci_esdhc_ops,
};

#ifdef CONFIG_OF
static int
sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
                         struct esdhc_platform_data *boarddata)
{
        struct device_node *np = pdev->dev.of_node;

        if (!np)
                return -ENODEV;

        if (of_get_property(np, "non-removable", NULL))
                boarddata->cd_type = ESDHC_CD_PERMANENT;

        if (of_get_property(np, "fsl,cd-controller", NULL))
                boarddata->cd_type = ESDHC_CD_CONTROLLER;

        if (of_get_property(np, "fsl,wp-controller", NULL))
                boarddata->wp_type = ESDHC_WP_CONTROLLER;

        boarddata->cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
        if (gpio_is_valid(boarddata->cd_gpio))
                boarddata->cd_type = ESDHC_CD_GPIO;

        boarddata->wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
        if (gpio_is_valid(boarddata->wp_gpio))
                boarddata->wp_type = ESDHC_WP_GPIO;

        of_property_read_u32(np, "bus-width", &boarddata->max_bus_width);

        return 0;
}
#else
static inline int
sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
                         struct esdhc_platform_data *boarddata)
{
        return -ENODEV;
}
#endif

static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
{
        const struct of_device_id *of_id =
                        of_match_device(imx_esdhc_dt_ids, &pdev->dev);
        struct sdhci_pltfm_host *pltfm_host;
        struct sdhci_host *host;
        struct esdhc_platform_data *boarddata;
        int err;
        struct pltfm_imx_data *imx_data;

        host = sdhci_pltfm_init(pdev, &sdhci_esdhc_imx_pdata);
        if (IS_ERR(host))
                return PTR_ERR(host);

        pltfm_host = sdhci_priv(host);

        imx_data = devm_kzalloc(&pdev->dev, sizeof(*imx_data), GFP_KERNEL);
        if (!imx_data) {
                err = -ENOMEM;
                goto free_sdhci;
        }

        if (of_id)
                pdev->id_entry = of_id->data;
        imx_data->devtype = pdev->id_entry->driver_data;
        pltfm_host->priv = imx_data;

        imx_data->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
        if (IS_ERR(imx_data->clk_ipg)) {
                err = PTR_ERR(imx_data->clk_ipg);
                goto free_sdhci;
        }

        imx_data->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
        if (IS_ERR(imx_data->clk_ahb)) {
                err = PTR_ERR(imx_data->clk_ahb);
                goto free_sdhci;
        }

        imx_data->clk_per = devm_clk_get(&pdev->dev, "per");
        if (IS_ERR(imx_data->clk_per)) {
                err = PTR_ERR(imx_data->clk_per);
                goto free_sdhci;
        }

        pltfm_host->clk = imx_data->clk_per;

        clk_prepare_enable(imx_data->clk_per);
        clk_prepare_enable(imx_data->clk_ipg);
        clk_prepare_enable(imx_data->clk_ahb);

        imx_data->pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
        if (IS_ERR(imx_data->pinctrl)) {
                err = PTR_ERR(imx_data->pinctrl);
                goto disable_clk;
        }

        host->quirks |= SDHCI_QUIRK_BROKEN_TIMEOUT_VAL;

        if (is_imx25_esdhc(imx_data) || is_imx35_esdhc(imx_data))
                /* Fix errata ENGcm07207 present on i.MX25 and i.MX35 */
                host->quirks |= SDHCI_QUIRK_NO_MULTIBLOCK
                        | SDHCI_QUIRK_BROKEN_ADMA;

        if (is_imx53_esdhc(imx_data))
                imx_data->flags |= ESDHC_FLAG_MULTIBLK_NO_INT;

        /*
         * The imx6q ROM code will change the default watermark level setting
         * to something insane.  Change it back here.
         */
        if (is_imx6q_usdhc(imx_data))
                writel(0x08100810, host->ioaddr + ESDHC_WTMK_LVL);

        boarddata = &imx_data->boarddata;
        if (sdhci_esdhc_imx_probe_dt(pdev, boarddata) < 0) {
                if (!host->mmc->parent->platform_data) {
                        dev_err(mmc_dev(host->mmc), "no board data!\n");
                        err = -EINVAL;
                        goto disable_clk;
                }
                imx_data->boarddata = *((struct esdhc_platform_data *)
                                        host->mmc->parent->platform_data);
        }

        /* write_protect */
        if (boarddata->wp_type == ESDHC_WP_GPIO) {
                err = mmc_gpio_request_ro(host->mmc, boarddata->wp_gpio);
                if (err) {
                        dev_err(mmc_dev(host->mmc),
                                "failed to request write-protect gpio!\n");
                        goto disable_clk;
                }
                host->mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
        }

        /* card_detect */
        switch (boarddata->cd_type) {
        case ESDHC_CD_GPIO:
                err = mmc_gpio_request_cd(host->mmc, boarddata->cd_gpio);
                if (err) {
                        dev_err(mmc_dev(host->mmc),
                                "failed to request card-detect gpio!\n");
                        goto disable_clk;
                }
                /* fall through */

        case ESDHC_CD_CONTROLLER:
                /* we have a working card_detect back */
                host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
                break;

        case ESDHC_CD_PERMANENT:
                host->mmc->caps = MMC_CAP_NONREMOVABLE;
                break;

        case ESDHC_CD_NONE:
                break;
        }

        switch (boarddata->max_bus_width) {
        case 8:
                host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;
                break;
        case 4:
                host->mmc->caps |= MMC_CAP_4_BIT_DATA;
                break;
        case 1:
        default:
                host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
                break;
        }

        err = sdhci_add_host(host);
        if (err)
                goto disable_clk;

        return 0;

disable_clk:
        clk_disable_unprepare(imx_data->clk_per);
        clk_disable_unprepare(imx_data->clk_ipg);
        clk_disable_unprepare(imx_data->clk_ahb);
free_sdhci:
        sdhci_pltfm_free(pdev);
        return err;
}

static int sdhci_esdhc_imx_remove(struct platform_device *pdev)
{
        struct sdhci_host *host = platform_get_drvdata(pdev);
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;
        int dead = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);

        sdhci_remove_host(host, dead);

        clk_disable_unprepare(imx_data->clk_per);
        clk_disable_unprepare(imx_data->clk_ipg);
        clk_disable_unprepare(imx_data->clk_ahb);

        sdhci_pltfm_free(pdev);

        return 0;
}

static struct platform_driver sdhci_esdhc_imx_driver = {
        .driver         = {
                .name   = "sdhci-esdhc-imx",
                .owner  = THIS_MODULE,
                .of_match_table = imx_esdhc_dt_ids,
                .pm     = SDHCI_PLTFM_PMOPS,
        },
        .id_table       = imx_esdhc_devtype,
        .probe          = sdhci_esdhc_imx_probe,
        .remove         = sdhci_esdhc_imx_remove,
};

module_platform_driver(sdhci_esdhc_imx_driver);

MODULE_DESCRIPTION("SDHCI driver for Freescale i.MX eSDHC");
MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
MODULE_LICENSE("GPL v2");