/*
 * Copyright (c) 2014-2015 MediaTek Inc.
 * Author: Chaotian.Jing <chaotian.jing@mediatek.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <linux/mmc/card.h>
#include <linux/mmc/core.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/slot-gpio.h>

#define MAX_BD_NUM          1024

/*--------------------------------------------------------------------------*/
/* Common Definition                                                        */
/*--------------------------------------------------------------------------*/
#define MSDC_BUS_1BITS          0x0
#define MSDC_BUS_4BITS          0x1
#define MSDC_BUS_8BITS          0x2

#define MSDC_BURST_64B          0x6

/*--------------------------------------------------------------------------*/
/* Register Offset                                                          */
/*--------------------------------------------------------------------------*/
#define MSDC_CFG         0x0
#define MSDC_IOCON       0x04
#define MSDC_PS          0x08
#define MSDC_INT         0x0c
#define MSDC_INTEN       0x10
#define MSDC_FIFOCS      0x14
#define SDC_CFG          0x30
#define SDC_CMD          0x34
#define SDC_ARG          0x38
#define SDC_STS          0x3c
#define SDC_RESP0        0x40
#define SDC_RESP1        0x44
#define SDC_RESP2        0x48
#define SDC_RESP3        0x4c
#define SDC_BLK_NUM      0x50
#define EMMC_IOCON       0x7c
#define SDC_ACMD_RESP    0x80
#define MSDC_DMA_SA      0x90
#define MSDC_DMA_CTRL    0x98
#define MSDC_DMA_CFG     0x9c
#define MSDC_PATCH_BIT   0xb0
#define MSDC_PATCH_BIT1  0xb4
#define MSDC_PAD_TUNE    0xec
#define PAD_DS_TUNE      0x188
#define EMMC50_CFG0      0x208

/*--------------------------------------------------------------------------*/
/* Register Mask                                                            */
/*--------------------------------------------------------------------------*/

/* MSDC_CFG mask */
#define MSDC_CFG_MODE           (0x1 << 0)      /* RW */
#define MSDC_CFG_CKPDN          (0x1 << 1)      /* RW */
#define MSDC_CFG_RST            (0x1 << 2)      /* RW */
#define MSDC_CFG_PIO            (0x1 << 3)      /* RW */
#define MSDC_CFG_CKDRVEN        (0x1 << 4)      /* RW */
#define MSDC_CFG_BV18SDT        (0x1 << 5)      /* RW */
#define MSDC_CFG_BV18PSS        (0x1 << 6)      /* R  */
#define MSDC_CFG_CKSTB          (0x1 << 7)      /* R  */
#define MSDC_CFG_CKDIV          (0xff << 8)     /* RW */
#define MSDC_CFG_CKMOD          (0x3 << 16)     /* RW */
#define MSDC_CFG_HS400_CK_MODE  (0x1 << 18)     /* RW */

/* MSDC_IOCON mask */
#define MSDC_IOCON_SDR104CKS    (0x1 << 0)      /* RW */
#define MSDC_IOCON_RSPL         (0x1 << 1)      /* RW */
#define MSDC_IOCON_DSPL         (0x1 << 2)      /* RW */
#define MSDC_IOCON_DDLSEL       (0x1 << 3)      /* RW */
#define MSDC_IOCON_DDR50CKD     (0x1 << 4)      /* RW */
#define MSDC_IOCON_DSPLSEL      (0x1 << 5)      /* RW */
#define MSDC_IOCON_W_DSPL       (0x1 << 8)      /* RW */
#define MSDC_IOCON_D0SPL        (0x1 << 16)     /* RW */
#define MSDC_IOCON_D1SPL        (0x1 << 17)     /* RW */
#define MSDC_IOCON_D2SPL        (0x1 << 18)     /* RW */
#define MSDC_IOCON_D3SPL        (0x1 << 19)     /* RW */
#define MSDC_IOCON_D4SPL        (0x1 << 20)     /* RW */
#define MSDC_IOCON_D5SPL        (0x1 << 21)     /* RW */
#define MSDC_IOCON_D6SPL        (0x1 << 22)     /* RW */
#define MSDC_IOCON_D7SPL        (0x1 << 23)     /* RW */
#define MSDC_IOCON_RISCSZ       (0x3 << 24)     /* RW */

/* MSDC_PS mask */
#define MSDC_PS_CDEN            (0x1 << 0)      /* RW */
#define MSDC_PS_CDSTS           (0x1 << 1)      /* R  */
#define MSDC_PS_CDDEBOUNCE      (0xf << 12)     /* RW */
#define MSDC_PS_DAT             (0xff << 16)    /* R  */
#define MSDC_PS_CMD             (0x1 << 24)     /* R  */
#define MSDC_PS_WP              (0x1 << 31)     /* R  */

/* MSDC_INT mask */
#define MSDC_INT_MMCIRQ         (0x1 << 0)      /* W1C */
#define MSDC_INT_CDSC           (0x1 << 1)      /* W1C */
#define MSDC_INT_ACMDRDY        (0x1 << 3)      /* W1C */
#define MSDC_INT_ACMDTMO        (0x1 << 4)      /* W1C */
#define MSDC_INT_ACMDCRCERR     (0x1 << 5)      /* W1C */
#define MSDC_INT_DMAQ_EMPTY     (0x1 << 6)      /* W1C */
#define MSDC_INT_SDIOIRQ        (0x1 << 7)      /* W1C */
#define MSDC_INT_CMDRDY         (0x1 << 8)      /* W1C */
#define MSDC_INT_CMDTMO         (0x1 << 9)      /* W1C */
#define MSDC_INT_RSPCRCERR      (0x1 << 10)     /* W1C */
#define MSDC_INT_CSTA           (0x1 << 11)     /* R */
#define MSDC_INT_XFER_COMPL     (0x1 << 12)     /* W1C */
#define MSDC_INT_DXFER_DONE     (0x1 << 13)     /* W1C */
#define MSDC_INT_DATTMO         (0x1 << 14)     /* W1C */
#define MSDC_INT_DATCRCERR      (0x1 << 15)     /* W1C */
#define MSDC_INT_ACMD19_DONE    (0x1 << 16)     /* W1C */
#define MSDC_INT_DMA_BDCSERR    (0x1 << 17)     /* W1C */
#define MSDC_INT_DMA_GPDCSERR   (0x1 << 18)     /* W1C */
#define MSDC_INT_DMA_PROTECT    (0x1 << 19)     /* W1C */

/* MSDC_INTEN mask */
#define MSDC_INTEN_MMCIRQ       (0x1 << 0)      /* RW */
#define MSDC_INTEN_CDSC         (0x1 << 1)      /* RW */
#define MSDC_INTEN_ACMDRDY      (0x1 << 3)      /* RW */
#define MSDC_INTEN_ACMDTMO      (0x1 << 4)      /* RW */
#define MSDC_INTEN_ACMDCRCERR   (0x1 << 5)      /* RW */
#define MSDC_INTEN_DMAQ_EMPTY   (0x1 << 6)      /* RW */
#define MSDC_INTEN_SDIOIRQ      (0x1 << 7)      /* RW */
#define MSDC_INTEN_CMDRDY       (0x1 << 8)      /* RW */
#define MSDC_INTEN_CMDTMO       (0x1 << 9)      /* RW */
#define MSDC_INTEN_RSPCRCERR    (0x1 << 10)     /* RW */
#define MSDC_INTEN_CSTA         (0x1 << 11)     /* RW */
#define MSDC_INTEN_XFER_COMPL   (0x1 << 12)     /* RW */
#define MSDC_INTEN_DXFER_DONE   (0x1 << 13)     /* RW */
#define MSDC_INTEN_DATTMO       (0x1 << 14)     /* RW */
#define MSDC_INTEN_DATCRCERR    (0x1 << 15)     /* RW */
#define MSDC_INTEN_ACMD19_DONE  (0x1 << 16)     /* RW */
#define MSDC_INTEN_DMA_BDCSERR  (0x1 << 17)     /* RW */
#define MSDC_INTEN_DMA_GPDCSERR (0x1 << 18)     /* RW */
#define MSDC_INTEN_DMA_PROTECT  (0x1 << 19)     /* RW */

/* MSDC_FIFOCS mask */
#define MSDC_FIFOCS_RXCNT       (0xff << 0)     /* R */
#define MSDC_FIFOCS_TXCNT       (0xff << 16)    /* R */
#define MSDC_FIFOCS_CLR         (0x1 << 31)     /* RW */

/* SDC_CFG mask */
#define SDC_CFG_SDIOINTWKUP     (0x1 << 0)      /* RW */
#define SDC_CFG_INSWKUP         (0x1 << 1)      /* RW */
#define SDC_CFG_BUSWIDTH        (0x3 << 16)     /* RW */
#define SDC_CFG_SDIO            (0x1 << 19)     /* RW */
#define SDC_CFG_SDIOIDE         (0x1 << 20)     /* RW */
#define SDC_CFG_INTATGAP        (0x1 << 21)     /* RW */
#define SDC_CFG_DTOC            (0xff << 24)    /* RW */

/* SDC_STS mask */
#define SDC_STS_SDCBUSY         (0x1 << 0)      /* RW */
#define SDC_STS_CMDBUSY         (0x1 << 1)      /* RW */
#define SDC_STS_SWR_COMPL       (0x1 << 31)     /* RW */

/* MSDC_DMA_CTRL mask */
#define MSDC_DMA_CTRL_START     (0x1 << 0)      /* W */
#define MSDC_DMA_CTRL_STOP      (0x1 << 1)      /* W */
#define MSDC_DMA_CTRL_RESUME    (0x1 << 2)      /* W */
#define MSDC_DMA_CTRL_MODE      (0x1 << 8)      /* RW */
#define MSDC_DMA_CTRL_LASTBUF   (0x1 << 10)     /* RW */
#define MSDC_DMA_CTRL_BRUSTSZ   (0x7 << 12)     /* RW */

/* MSDC_DMA_CFG mask */
#define MSDC_DMA_CFG_STS        (0x1 << 0)      /* R */
#define MSDC_DMA_CFG_DECSEN     (0x1 << 1)      /* RW */
#define MSDC_DMA_CFG_AHBHPROT2  (0x2 << 8)      /* RW */
#define MSDC_DMA_CFG_ACTIVEEN   (0x2 << 12)     /* RW */
#define MSDC_DMA_CFG_CS12B16B   (0x1 << 16)     /* RW */

/* MSDC_PATCH_BIT mask */
#define MSDC_PATCH_BIT_ODDSUPP    (0x1 <<  1)   /* RW */
#define MSDC_INT_DAT_LATCH_CK_SEL (0x7 <<  7)
#define MSDC_CKGEN_MSDC_DLY_SEL   (0x1f << 10)
#define MSDC_PATCH_BIT_IODSSEL    (0x1 << 16)   /* RW */
#define MSDC_PATCH_BIT_IOINTSEL   (0x1 << 17)   /* RW */
#define MSDC_PATCH_BIT_BUSYDLY    (0xf << 18)   /* RW */
#define MSDC_PATCH_BIT_WDOD       (0xf << 22)   /* RW */
#define MSDC_PATCH_BIT_IDRTSEL    (0x1 << 26)   /* RW */
#define MSDC_PATCH_BIT_CMDFSEL    (0x1 << 27)   /* RW */
#define MSDC_PATCH_BIT_INTDLSEL   (0x1 << 28)   /* RW */
#define MSDC_PATCH_BIT_SPCPUSH    (0x1 << 29)   /* RW */
#define MSDC_PATCH_BIT_DECRCTMO   (0x1 << 30)   /* RW */

#define MSDC_PAD_TUNE_DATRRDLY    (0x1f <<  8)  /* RW */
#define MSDC_PAD_TUNE_CMDRDLY     (0x1f << 16)  /* RW */

#define PAD_DS_TUNE_DLY1          (0x1f << 2)   /* RW */
#define PAD_DS_TUNE_DLY2          (0x1f << 7)   /* RW */
#define PAD_DS_TUNE_DLY3          (0x1f << 12)  /* RW */

#define EMMC50_CFG_PADCMD_LATCHCK (0x1 << 0)   /* RW */
#define EMMC50_CFG_CRCSTS_EDGE    (0x1 << 3)   /* RW */
#define EMMC50_CFG_CFCSTS_SEL     (0x1 << 4)   /* RW */

#define REQ_CMD_EIO  (0x1 << 0)
#define REQ_CMD_TMO  (0x1 << 1)
#define REQ_DAT_ERR  (0x1 << 2)
#define REQ_STOP_EIO (0x1 << 3)
#define REQ_STOP_TMO (0x1 << 4)
#define REQ_CMD_BUSY (0x1 << 5)

#define MSDC_PREPARE_FLAG (0x1 << 0)
#define MSDC_ASYNC_FLAG (0x1 << 1)
#define MSDC_MMAP_FLAG (0x1 << 2)

#define MTK_MMC_AUTOSUSPEND_DELAY       50
#define CMD_TIMEOUT         (HZ/10 * 5) /* 100ms x5 */
#define DAT_TIMEOUT         (HZ    * 5) /* 1000ms x5 */

#define PAD_DELAY_MAX   32 /* PAD delay cells */
/*--------------------------------------------------------------------------*/
/* Descriptor Structure                                                     */
/*--------------------------------------------------------------------------*/
struct mt_gpdma_desc {
        u32 gpd_info;
#define GPDMA_DESC_HWO          (0x1 << 0)
#define GPDMA_DESC_BDP          (0x1 << 1)
#define GPDMA_DESC_CHECKSUM     (0xff << 8) /* bit8 ~ bit15 */
#define GPDMA_DESC_INT          (0x1 << 16)
        u32 next;
        u32 ptr;
        u32 gpd_data_len;
#define GPDMA_DESC_BUFLEN       (0xffff) /* bit0 ~ bit15 */
#define GPDMA_DESC_EXTLEN       (0xff << 16) /* bit16 ~ bit23 */
        u32 arg;
        u32 blknum;
        u32 cmd;
};

struct mt_bdma_desc {
        u32 bd_info;
#define BDMA_DESC_EOL           (0x1 << 0)
#define BDMA_DESC_CHECKSUM      (0xff << 8) /* bit8 ~ bit15 */
#define BDMA_DESC_BLKPAD        (0x1 << 17)
#define BDMA_DESC_DWPAD         (0x1 << 18)
        u32 next;
        u32 ptr;
        u32 bd_data_len;
#define BDMA_DESC_BUFLEN        (0xffff) /* bit0 ~ bit15 */
};

struct msdc_dma {
        struct scatterlist *sg; /* I/O scatter list */
        struct mt_gpdma_desc *gpd;              /* pointer to gpd array */
        struct mt_bdma_desc *bd;                /* pointer to bd array */
        dma_addr_t gpd_addr;    /* the physical address of gpd array */
        dma_addr_t bd_addr;     /* the physical address of bd array */
};

struct msdc_save_para {
        u32 msdc_cfg;
        u32 iocon;
        u32 sdc_cfg;
        u32 pad_tune;
        u32 patch_bit0;
        u32 patch_bit1;
        u32 pad_ds_tune;
        u32 emmc50_cfg0;
};

struct msdc_tune_para {
        u32 iocon;
        u32 pad_tune;
};

struct msdc_delay_phase {
        u8 maxlen;
        u8 start;
        u8 final_phase;
};

struct msdc_host {
        struct device *dev;
        struct mmc_host *mmc;   /* mmc structure */
        int cmd_rsp;

        spinlock_t lock;
        struct mmc_request *mrq;
        struct mmc_command *cmd;
        struct mmc_data *data;
        int error;

        void __iomem *base;             /* host base address */

        struct msdc_dma dma;    /* dma channel */
        u64 dma_mask;

        u32 timeout_ns;         /* data timeout ns */
        u32 timeout_clks;       /* data timeout clks */

        struct pinctrl *pinctrl;
        struct pinctrl_state *pins_default;
        struct pinctrl_state *pins_uhs;
        struct delayed_work req_timeout;
        int irq;                /* host interrupt */

        struct clk *src_clk;    /* msdc source clock */
        struct clk *h_clk;      /* msdc h_clk */
        u32 mclk;               /* mmc subsystem clock frequency */
        u32 src_clk_freq;       /* source clock frequency */
        u32 sclk;               /* SD/MS bus clock frequency */
        unsigned char timing;
        bool vqmmc_enabled;
        u32 hs400_ds_delay;
        bool hs400_mode;        /* current eMMC will run at hs400 mode */
        struct msdc_save_para save_para; /* used when gate HCLK */
        struct msdc_tune_para def_tune_para; /* default tune setting */
        struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
};

static void sdr_set_bits(void __iomem *reg, u32 bs)
{
        u32 val = readl(reg);

        val |= bs;
        writel(val, reg);
}

static void sdr_clr_bits(void __iomem *reg, u32 bs)
{
        u32 val = readl(reg);

        val &= ~bs;
        writel(val, reg);
}

static void sdr_set_field(void __iomem *reg, u32 field, u32 val)
{
        unsigned int tv = readl(reg);

        tv &= ~field;
        tv |= ((val) << (ffs((unsigned int)field) - 1));
        writel(tv, reg);
}

static void sdr_get_field(void __iomem *reg, u32 field, u32 *val)
{
        unsigned int tv = readl(reg);

        *val = ((tv & field) >> (ffs((unsigned int)field) - 1));
}

static void msdc_reset_hw(struct msdc_host *host)
{
        u32 val;

        sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_RST);
        while (readl(host->base + MSDC_CFG) & MSDC_CFG_RST)
                cpu_relax();

        sdr_set_bits(host->base + MSDC_FIFOCS, MSDC_FIFOCS_CLR);
        while (readl(host->base + MSDC_FIFOCS) & MSDC_FIFOCS_CLR)
                cpu_relax();

        val = readl(host->base + MSDC_INT);
        writel(val, host->base + MSDC_INT);
}

static void msdc_cmd_next(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd);

static const u32 cmd_ints_mask = MSDC_INTEN_CMDRDY | MSDC_INTEN_RSPCRCERR |
                        MSDC_INTEN_CMDTMO | MSDC_INTEN_ACMDRDY |
                        MSDC_INTEN_ACMDCRCERR | MSDC_INTEN_ACMDTMO;
static const u32 data_ints_mask = MSDC_INTEN_XFER_COMPL | MSDC_INTEN_DATTMO |
                        MSDC_INTEN_DATCRCERR | MSDC_INTEN_DMA_BDCSERR |
                        MSDC_INTEN_DMA_GPDCSERR | MSDC_INTEN_DMA_PROTECT;

static u8 msdc_dma_calcs(u8 *buf, u32 len)
{
        u32 i, sum = 0;

        for (i = 0; i < len; i++)
                sum += buf[i];
        return 0xff - (u8) sum;
}

static inline void msdc_dma_setup(struct msdc_host *host, struct msdc_dma *dma,
                struct mmc_data *data)
{
        unsigned int j, dma_len;
        dma_addr_t dma_address;
        u32 dma_ctrl;
        struct scatterlist *sg;
        struct mt_gpdma_desc *gpd;
        struct mt_bdma_desc *bd;

        sg = data->sg;

        gpd = dma->gpd;
        bd = dma->bd;

        /* modify gpd */
        gpd->gpd_info |= GPDMA_DESC_HWO;
        gpd->gpd_info |= GPDMA_DESC_BDP;
        /* need to clear first. use these bits to calc checksum */
        gpd->gpd_info &= ~GPDMA_DESC_CHECKSUM;
        gpd->gpd_info |= msdc_dma_calcs((u8 *) gpd, 16) << 8;

        /* modify bd */
        for_each_sg(data->sg, sg, data->sg_count, j) {
                dma_address = sg_dma_address(sg);
                dma_len = sg_dma_len(sg);

                /* init bd */
                bd[j].bd_info &= ~BDMA_DESC_BLKPAD;
                bd[j].bd_info &= ~BDMA_DESC_DWPAD;
                bd[j].ptr = (u32)dma_address;
                bd[j].bd_data_len &= ~BDMA_DESC_BUFLEN;
                bd[j].bd_data_len |= (dma_len & BDMA_DESC_BUFLEN);

                if (j == data->sg_count - 1) /* the last bd */
                        bd[j].bd_info |= BDMA_DESC_EOL;
                else
                        bd[j].bd_info &= ~BDMA_DESC_EOL;

                /* checksume need to clear first */
                bd[j].bd_info &= ~BDMA_DESC_CHECKSUM;
                bd[j].bd_info |= msdc_dma_calcs((u8 *)(&bd[j]), 16) << 8;
        }

        sdr_set_field(host->base + MSDC_DMA_CFG, MSDC_DMA_CFG_DECSEN, 1);
        dma_ctrl = readl_relaxed(host->base + MSDC_DMA_CTRL);
        dma_ctrl &= ~(MSDC_DMA_CTRL_BRUSTSZ | MSDC_DMA_CTRL_MODE);
        dma_ctrl |= (MSDC_BURST_64B << 12 | 1 << 8);
        writel_relaxed(dma_ctrl, host->base + MSDC_DMA_CTRL);
        writel((u32)dma->gpd_addr, host->base + MSDC_DMA_SA);
}

static void msdc_prepare_data(struct msdc_host *host, struct mmc_request *mrq)
{
        struct mmc_data *data = mrq->data;

        if (!(data->host_cookie & MSDC_PREPARE_FLAG)) {
                bool read = (data->flags & MMC_DATA_READ) != 0;

                data->host_cookie |= MSDC_PREPARE_FLAG;
                data->sg_count = dma_map_sg(host->dev, data->sg, data->sg_len,
                                           read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
        }
}

static void msdc_unprepare_data(struct msdc_host *host, struct mmc_request *mrq)
{
        struct mmc_data *data = mrq->data;

        if (data->host_cookie & MSDC_ASYNC_FLAG)
                return;

        if (data->host_cookie & MSDC_PREPARE_FLAG) {
                bool read = (data->flags & MMC_DATA_READ) != 0;

                dma_unmap_sg(host->dev, data->sg, data->sg_len,
                             read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
                data->host_cookie &= ~MSDC_PREPARE_FLAG;
        }
}

/* clock control primitives */
static void msdc_set_timeout(struct msdc_host *host, u32 ns, u32 clks)
{
        u32 timeout, clk_ns;
        u32 mode = 0;

        host->timeout_ns = ns;
        host->timeout_clks = clks;
        if (host->sclk == 0) {
                timeout = 0;
        } else {
                clk_ns  = 1000000000UL / host->sclk;
                timeout = (ns + clk_ns - 1) / clk_ns + clks;
                /* in 1048576 sclk cycle unit */
                timeout = (timeout + (0x1 << 20) - 1) >> 20;
                sdr_get_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD, &mode);
                /*DDR mode will double the clk cycles for data timeout */
                timeout = mode >= 2 ? timeout * 2 : timeout;
                timeout = timeout > 1 ? timeout - 1 : 0;
                timeout = timeout > 255 ? 255 : timeout;
        }
        sdr_set_field(host->base + SDC_CFG, SDC_CFG_DTOC, timeout);
}

static void msdc_gate_clock(struct msdc_host *host)
{
        clk_disable_unprepare(host->src_clk);
        clk_disable_unprepare(host->h_clk);
}

static void msdc_ungate_clock(struct msdc_host *host)
{
        clk_prepare_enable(host->h_clk);
        clk_prepare_enable(host->src_clk);
        while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
                cpu_relax();
}

static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
{
        u32 mode;
        u32 flags;
        u32 div;
        u32 sclk;

        if (!hz) {
                dev_dbg(host->dev, "set mclk to 0\n");
                host->mclk = 0;
                sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN);
                return;
        }

        flags = readl(host->base + MSDC_INTEN);
        sdr_clr_bits(host->base + MSDC_INTEN, flags);
        sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_HS400_CK_MODE);
        if (timing == MMC_TIMING_UHS_DDR50 ||
            timing == MMC_TIMING_MMC_DDR52 ||
            timing == MMC_TIMING_MMC_HS400) {
                if (timing == MMC_TIMING_MMC_HS400)
                        mode = 0x3;
                else
                        mode = 0x2; /* ddr mode and use divisor */

                if (hz >= (host->src_clk_freq >> 2)) {
                        div = 0; /* mean div = 1/4 */
                        sclk = host->src_clk_freq >> 2; /* sclk = clk / 4 */
                } else {
                        div = (host->src_clk_freq + ((hz << 2) - 1)) / (hz << 2);
                        sclk = (host->src_clk_freq >> 2) / div;
                        div = (div >> 1);
                }

                if (timing == MMC_TIMING_MMC_HS400 &&
                    hz >= (host->src_clk_freq >> 1)) {
                        sdr_set_bits(host->base + MSDC_CFG,
                                     MSDC_CFG_HS400_CK_MODE);
                        sclk = host->src_clk_freq >> 1;
                        div = 0; /* div is ignore when bit18 is set */
                }
        } else if (hz >= host->src_clk_freq) {
                mode = 0x1; /* no divisor */
                div = 0;
                sclk = host->src_clk_freq;
        } else {
                mode = 0x0; /* use divisor */
                if (hz >= (host->src_clk_freq >> 1)) {
                        div = 0; /* mean div = 1/2 */
                        sclk = host->src_clk_freq >> 1; /* sclk = clk / 2 */
                } else {
                        div = (host->src_clk_freq + ((hz << 2) - 1)) / (hz << 2);
                        sclk = (host->src_clk_freq >> 2) / div;
                }
        }
        sdr_set_field(host->base + MSDC_CFG, MSDC_CFG_CKMOD | MSDC_CFG_CKDIV,
                        (mode << 8) | (div % 0xff));
        sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN);
        while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
                cpu_relax();
        host->sclk = sclk;
        host->mclk = hz;
        host->timing = timing;
        /* need because clk changed. */
        msdc_set_timeout(host, host->timeout_ns, host->timeout_clks);
        sdr_set_bits(host->base + MSDC_INTEN, flags);

        /*
         * mmc_select_hs400() will drop to 50Mhz and High speed mode,
         * tune result of hs200/200Mhz is not suitable for 50Mhz
         */
        if (host->sclk <= 52000000) {
                writel(host->def_tune_para.iocon, host->base + MSDC_IOCON);
                writel(host->def_tune_para.pad_tune, host->base + MSDC_PAD_TUNE);
        } else {
                writel(host->saved_tune_para.iocon, host->base + MSDC_IOCON);
                writel(host->saved_tune_para.pad_tune, host->base + MSDC_PAD_TUNE);
        }

        dev_dbg(host->dev, "sclk: %d, timing: %d\n", host->sclk, timing);
}

static inline u32 msdc_cmd_find_resp(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd)
{
        u32 resp;

        switch (mmc_resp_type(cmd)) {
                /* Actually, R1, R5, R6, R7 are the same */
        case MMC_RSP_R1:
                resp = 0x1;
                break;
        case MMC_RSP_R1B:
                resp = 0x7;
                break;
        case MMC_RSP_R2:
                resp = 0x2;
                break;
        case MMC_RSP_R3:
                resp = 0x3;
                break;
        case MMC_RSP_NONE:
        default:
                resp = 0x0;
                break;
        }

        return resp;
}

static inline u32 msdc_cmd_prepare_raw_cmd(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd)
{
        /* rawcmd :
         * vol_swt << 30 | auto_cmd << 28 | blklen << 16 | go_irq << 15 |
         * stop << 14 | rw << 13 | dtype << 11 | rsptyp << 7 | brk << 6 | opcode
         */
        u32 opcode = cmd->opcode;
        u32 resp = msdc_cmd_find_resp(host, mrq, cmd);
        u32 rawcmd = (opcode & 0x3f) | ((resp & 0x7) << 7);

        host->cmd_rsp = resp;

        if ((opcode == SD_IO_RW_DIRECT && cmd->flags == (unsigned int) -1) ||
            opcode == MMC_STOP_TRANSMISSION)
                rawcmd |= (0x1 << 14);
        else if (opcode == SD_SWITCH_VOLTAGE)
                rawcmd |= (0x1 << 30);
        else if (opcode == SD_APP_SEND_SCR ||
                 opcode == SD_APP_SEND_NUM_WR_BLKS ||
                 (opcode == SD_SWITCH && mmc_cmd_type(cmd) == MMC_CMD_ADTC) ||
                 (opcode == SD_APP_SD_STATUS && mmc_cmd_type(cmd) == MMC_CMD_ADTC) ||
                 (opcode == MMC_SEND_EXT_CSD && mmc_cmd_type(cmd) == MMC_CMD_ADTC))
                rawcmd |= (0x1 << 11);

        if (cmd->data) {
                struct mmc_data *data = cmd->data;

                if (mmc_op_multi(opcode)) {
                        if (mmc_card_mmc(host->mmc->card) && mrq->sbc &&
                            !(mrq->sbc->arg & 0xFFFF0000))
                                rawcmd |= 0x2 << 28; /* AutoCMD23 */
                }

                rawcmd |= ((data->blksz & 0xFFF) << 16);
                if (data->flags & MMC_DATA_WRITE)
                        rawcmd |= (0x1 << 13);
                if (data->blocks > 1)
                        rawcmd |= (0x2 << 11);
                else
                        rawcmd |= (0x1 << 11);
                /* Always use dma mode */
                sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_PIO);

                if (host->timeout_ns != data->timeout_ns ||
                    host->timeout_clks != data->timeout_clks)
                        msdc_set_timeout(host, data->timeout_ns,
                                        data->timeout_clks);

                writel(data->blocks, host->base + SDC_BLK_NUM);
        }
        return rawcmd;
}

static void msdc_start_data(struct msdc_host *host, struct mmc_request *mrq,
                            struct mmc_command *cmd, struct mmc_data *data)
{
        bool read;

        WARN_ON(host->data);
        host->data = data;
        read = data->flags & MMC_DATA_READ;

        mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
        msdc_dma_setup(host, &host->dma, data);
        sdr_set_bits(host->base + MSDC_INTEN, data_ints_mask);
        sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_START, 1);
        dev_dbg(host->dev, "DMA start\n");
        dev_dbg(host->dev, "%s: cmd=%d DMA data: %d blocks; read=%d\n",
                        __func__, cmd->opcode, data->blocks, read);
}

static int msdc_auto_cmd_done(struct msdc_host *host, int events,
                struct mmc_command *cmd)
{
        u32 *rsp = cmd->resp;

        rsp[0] = readl(host->base + SDC_ACMD_RESP);

        if (events & MSDC_INT_ACMDRDY) {
                cmd->error = 0;
        } else {
                msdc_reset_hw(host);
                if (events & MSDC_INT_ACMDCRCERR) {
                        cmd->error = -EILSEQ;
                        host->error |= REQ_STOP_EIO;
                } else if (events & MSDC_INT_ACMDTMO) {
                        cmd->error = -ETIMEDOUT;
                        host->error |= REQ_STOP_TMO;
                }
                dev_err(host->dev,
                        "%s: AUTO_CMD%d arg=%08X; rsp %08X; cmd_error=%d\n",
                        __func__, cmd->opcode, cmd->arg, rsp[0], cmd->error);
        }
        return cmd->error;
}

static void msdc_track_cmd_data(struct msdc_host *host,
                                struct mmc_command *cmd, struct mmc_data *data)
{
        if (host->error)
                dev_dbg(host->dev, "%s: cmd=%d arg=%08X; host->error=0x%08X\n",
                        __func__, cmd->opcode, cmd->arg, host->error);
}

static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq)
{
        unsigned long flags;
        bool ret;

        ret = cancel_delayed_work(&host->req_timeout);
        if (!ret) {
                /* delay work already running */
                return;
        }
        spin_lock_irqsave(&host->lock, flags);
        host->mrq = NULL;
        spin_unlock_irqrestore(&host->lock, flags);

        msdc_track_cmd_data(host, mrq->cmd, mrq->data);
        if (mrq->data)
                msdc_unprepare_data(host, mrq);
        mmc_request_done(host->mmc, mrq);
}

/* returns true if command is fully handled; returns false otherwise */
static bool msdc_cmd_done(struct msdc_host *host, int events,
                          struct mmc_request *mrq, struct mmc_command *cmd)
{
        bool done = false;
        bool sbc_error;
        unsigned long flags;
        u32 *rsp = cmd->resp;

        if (mrq->sbc && cmd == mrq->cmd &&
            (events & (MSDC_INT_ACMDRDY | MSDC_INT_ACMDCRCERR
                                   | MSDC_INT_ACMDTMO)))
                msdc_auto_cmd_done(host, events, mrq->sbc);

        sbc_error = mrq->sbc && mrq->sbc->error;

        if (!sbc_error && !(events & (MSDC_INT_CMDRDY
                                        | MSDC_INT_RSPCRCERR
                                        | MSDC_INT_CMDTMO)))
                return done;

        spin_lock_irqsave(&host->lock, flags);
        done = !host->cmd;
        host->cmd = NULL;
        spin_unlock_irqrestore(&host->lock, flags);

        if (done)
                return true;

        sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);

        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136) {
                        rsp[0] = readl(host->base + SDC_RESP3);
                        rsp[1] = readl(host->base + SDC_RESP2);
                        rsp[2] = readl(host->base + SDC_RESP1);
                        rsp[3] = readl(host->base + SDC_RESP0);
                } else {
                        rsp[0] = readl(host->base + SDC_RESP0);
                }
        }

        if (!sbc_error && !(events & MSDC_INT_CMDRDY)) {
                if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
                    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200)
                        /*
                         * should not clear fifo/interrupt as the tune data
                         * may have alreay come.
                         */
                        msdc_reset_hw(host);
                if (events & MSDC_INT_RSPCRCERR) {
                        cmd->error = -EILSEQ;
                        host->error |= REQ_CMD_EIO;
                } else if (events & MSDC_INT_CMDTMO) {
                        cmd->error = -ETIMEDOUT;
                        host->error |= REQ_CMD_TMO;
                }
        }
        if (cmd->error)
                dev_dbg(host->dev,
                                "%s: cmd=%d arg=%08X; rsp %08X; cmd_error=%d\n",
                                __func__, cmd->opcode, cmd->arg, rsp[0],
                                cmd->error);

        msdc_cmd_next(host, mrq, cmd);
        return true;
}

/* It is the core layer's responsibility to ensure card status
 * is correct before issue a request. but host design do below
 * checks recommended.
 */
static inline bool msdc_cmd_is_ready(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd)
{
        /* The max busy time we can endure is 20ms */
        unsigned long tmo = jiffies + msecs_to_jiffies(20);

        while ((readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) &&
                        time_before(jiffies, tmo))
                cpu_relax();
        if (readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) {
                dev_err(host->dev, "CMD bus busy detected\n");
                host->error |= REQ_CMD_BUSY;
                msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
                return false;
        }

        if (mmc_resp_type(cmd) == MMC_RSP_R1B || cmd->data) {
                tmo = jiffies + msecs_to_jiffies(20);
                /* R1B or with data, should check SDCBUSY */
                while ((readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) &&
                                time_before(jiffies, tmo))
                        cpu_relax();
                if (readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) {
                        dev_err(host->dev, "Controller busy detected\n");
                        host->error |= REQ_CMD_BUSY;
                        msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
                        return false;
                }
        }
        return true;
}

static void msdc_start_command(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd)
{
        u32 rawcmd;

        WARN_ON(host->cmd);
        host->cmd = cmd;

        if (!msdc_cmd_is_ready(host, mrq, cmd))
                return;

        if ((readl(host->base + MSDC_FIFOCS) & MSDC_FIFOCS_TXCNT) >> 16 ||
            readl(host->base + MSDC_FIFOCS) & MSDC_FIFOCS_RXCNT) {
                dev_err(host->dev, "TX/RX FIFO non-empty before start of IO. Reset\n");
                msdc_reset_hw(host);
        }

        cmd->error = 0;
        rawcmd = msdc_cmd_prepare_raw_cmd(host, mrq, cmd);
        mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);

        sdr_set_bits(host->base + MSDC_INTEN, cmd_ints_mask);
        writel(cmd->arg, host->base + SDC_ARG);
        writel(rawcmd, host->base + SDC_CMD);
}

static void msdc_cmd_next(struct msdc_host *host,
                struct mmc_request *mrq, struct mmc_command *cmd)
{
        if ((cmd->error &&
            !(cmd->error == -EILSEQ &&
              (cmd->opcode == MMC_SEND_TUNING_BLOCK ||
               cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200))) ||
            (mrq->sbc && mrq->sbc->error))
                msdc_request_done(host, mrq);
        else if (cmd == mrq->sbc)
                msdc_start_command(host, mrq, mrq->cmd);
        else if (!cmd->data)
                msdc_request_done(host, mrq);
        else
                msdc_start_data(host, mrq, cmd, cmd->data);
}

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

        host->error = 0;
        WARN_ON(host->mrq);
        host->mrq = mrq;

        if (mrq->data)
                msdc_prepare_data(host, mrq);

        /* if SBC is required, we have HW option and SW option.
         * if HW option is enabled, and SBC does not have "special" flags,
         * use HW option,  otherwise use SW option
         */
        if (mrq->sbc && (!mmc_card_mmc(mmc->card) ||
            (mrq->sbc->arg & 0xFFFF0000)))
                msdc_start_command(host, mrq, mrq->sbc);
        else
                msdc_start_command(host, mrq, mrq->cmd);
}

static void msdc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
                bool is_first_req)
{
        struct msdc_host *host = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!data)
                return;

        msdc_prepare_data(host, mrq);
        data->host_cookie |= MSDC_ASYNC_FLAG;
}

static void msdc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
                int err)
{
        struct msdc_host *host = mmc_priv(mmc);
        struct mmc_data *data;

        data = mrq->data;
        if (!data)
                return;
        if (data->host_cookie) {
                data->host_cookie &= ~MSDC_ASYNC_FLAG;
                msdc_unprepare_data(host, mrq);
        }
}

static void msdc_data_xfer_next(struct msdc_host *host,
                                struct mmc_request *mrq, struct mmc_data *data)
{
        if (mmc_op_multi(mrq->cmd->opcode) && mrq->stop && !mrq->stop->error &&
            !mrq->sbc)
                msdc_start_command(host, mrq, mrq->stop);
        else
                msdc_request_done(host, mrq);
}

static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
                                struct mmc_request *mrq, struct mmc_data *data)
{
        struct mmc_command *stop = data->stop;
        unsigned long flags;
        bool done;
        unsigned int check_data = events &
            (MSDC_INT_XFER_COMPL | MSDC_INT_DATCRCERR | MSDC_INT_DATTMO
             | MSDC_INT_DMA_BDCSERR | MSDC_INT_DMA_GPDCSERR
             | MSDC_INT_DMA_PROTECT);

        spin_lock_irqsave(&host->lock, flags);
        done = !host->data;
        if (check_data)
                host->data = NULL;
        spin_unlock_irqrestore(&host->lock, flags);

        if (done)
                return true;

        if (check_data || (stop && stop->error)) {
                dev_dbg(host->dev, "DMA status: 0x%8X\n",
                                readl(host->base + MSDC_DMA_CFG));
                sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_STOP,
                                1);
                while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
                        cpu_relax();
                sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
                dev_dbg(host->dev, "DMA stop\n");

                if ((events & MSDC_INT_XFER_COMPL) && (!stop || !stop->error)) {
                        data->bytes_xfered = data->blocks * data->blksz;
                } else {

                        dev_dbg(host->dev, "interrupt events: %x\n", events);
                        msdc_reset_hw(host);
                        host->error |= REQ_DAT_ERR;
                        data->bytes_xfered = 0;

                        if (events & MSDC_INT_DATTMO)
                                data->error = -ETIMEDOUT;
                        else if (events & MSDC_INT_DATCRCERR)
                                data->error = -EILSEQ;

                        dev_dbg(host->dev, "%s: cmd=%d; blocks=%d",
                                __func__, mrq->cmd->opcode, data->blocks);
                        dev_dbg(host->dev, "data_error=%d xfer_size=%d\n",
                                (int)data->error, data->bytes_xfered);
                }

                msdc_data_xfer_next(host, mrq, data);
                done = true;
        }
        return done;
}

static void msdc_set_buswidth(struct msdc_host *host, u32 width)
{
        u32 val = readl(host->base + SDC_CFG);

        val &= ~SDC_CFG_BUSWIDTH;

        switch (width) {
        default:
        case MMC_BUS_WIDTH_1:
                val |= (MSDC_BUS_1BITS << 16);
                break;
        case MMC_BUS_WIDTH_4:
                val |= (MSDC_BUS_4BITS << 16);
                break;
        case MMC_BUS_WIDTH_8:
                val |= (MSDC_BUS_8BITS << 16);
                break;
        }

        writel(val, host->base + SDC_CFG);
        dev_dbg(host->dev, "Bus Width = %d", width);
}

static int msdc_ops_switch_volt(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct msdc_host *host = mmc_priv(mmc);
        int ret = 0;

        if (!IS_ERR(mmc->supply.vqmmc)) {
                if (ios->signal_voltage != MMC_SIGNAL_VOLTAGE_330 &&
                    ios->signal_voltage != MMC_SIGNAL_VOLTAGE_180) {
                        dev_err(host->dev, "Unsupported signal voltage!\n");
                        return -EINVAL;
                }

                ret = mmc_regulator_set_vqmmc(mmc, ios);
                if (ret) {
                        dev_dbg(host->dev, "Regulator set error %d (%d)\n",
                                ret, ios->signal_voltage);
                } else {
                        /* Apply different pinctrl settings for different signal voltage */
                        if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
                                pinctrl_select_state(host->pinctrl, host->pins_uhs);
                        else
                                pinctrl_select_state(host->pinctrl, host->pins_default);
                }
        }
        return ret;
}

static int msdc_card_busy(struct mmc_host *mmc)
{
        struct msdc_host *host = mmc_priv(mmc);
        u32 status = readl(host->base + MSDC_PS);

        /* check if any pin between dat[0:3] is low */
        if (((status >> 16) & 0xf) != 0xf)
                return 1;

        return 0;
}

static void msdc_request_timeout(struct work_struct *work)
{
        struct msdc_host *host = container_of(work, struct msdc_host,
                        req_timeout.work);

        /* simulate HW timeout status */
        dev_err(host->dev, "%s: aborting cmd/data/mrq\n", __func__);
        if (host->mrq) {
                dev_err(host->dev, "%s: aborting mrq=%p cmd=%d\n", __func__,
                                host->mrq, host->mrq->cmd->opcode);
                if (host->cmd) {
                        dev_err(host->dev, "%s: aborting cmd=%d\n",
                                        __func__, host->cmd->opcode);
                        msdc_cmd_done(host, MSDC_INT_CMDTMO, host->mrq,
                                        host->cmd);
                } else if (host->data) {
                        dev_err(host->dev, "%s: abort data: cmd%d; %d blocks\n",
                                        __func__, host->mrq->cmd->opcode,
                                        host->data->blocks);
                        msdc_data_xfer_done(host, MSDC_INT_DATTMO, host->mrq,
                                        host->data);
                }
        }
}

static irqreturn_t msdc_irq(int irq, void *dev_id)
{
        struct msdc_host *host = (struct msdc_host *) dev_id;

        while (true) {
                unsigned long flags;
                struct mmc_request *mrq;
                struct mmc_command *cmd;
                struct mmc_data *data;
                u32 events, event_mask;

                spin_lock_irqsave(&host->lock, flags);
                events = readl(host->base + MSDC_INT);
                event_mask = readl(host->base + MSDC_INTEN);
                /* clear interrupts */
                writel(events & event_mask, host->base + MSDC_INT);

                mrq = host->mrq;
                cmd = host->cmd;
                data = host->data;
                spin_unlock_irqrestore(&host->lock, flags);

                if (!(events & event_mask))
                        break;

                if (!mrq) {
                        dev_err(host->dev,
                                "%s: MRQ=NULL; events=%08X; event_mask=%08X\n",
                                __func__, events, event_mask);
                        WARN_ON(1);
                        break;
                }

                dev_dbg(host->dev, "%s: events=%08X\n", __func__, events);

                if (cmd)
                        msdc_cmd_done(host, events, mrq, cmd);
                else if (data)
                        msdc_data_xfer_done(host, events, mrq, data);
        }

        return IRQ_HANDLED;
}

static void msdc_init_hw(struct msdc_host *host)
{
        u32 val;

        /* Configure to MMC/SD mode, clock free running */
        sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_MODE | MSDC_CFG_CKPDN);

        /* Reset */
        msdc_reset_hw(host);

        /* Disable card detection */
        sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);

        /* Disable and clear all interrupts */
        writel(0, host->base + MSDC_INTEN);
        val = readl(host->base + MSDC_INT);
        writel(val, host->base + MSDC_INT);

        writel(0, host->base + MSDC_PAD_TUNE);
        writel(0, host->base + MSDC_IOCON);
        sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DDLSEL, 0);
        writel(0x403c0046, host->base + MSDC_PATCH_BIT);
        sdr_set_field(host->base + MSDC_PATCH_BIT, MSDC_CKGEN_MSDC_DLY_SEL, 1);
        writel(0xffff0089, host->base + MSDC_PATCH_BIT1);
        sdr_set_bits(host->base + EMMC50_CFG0, EMMC50_CFG_CFCSTS_SEL);

        /* Configure to enable SDIO mode.
         * it's must otherwise sdio cmd5 failed
         */
        sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIO);

        /* disable detect SDIO device interrupt function */
        sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);

        /* Configure to default data timeout */
        sdr_set_field(host->base + SDC_CFG, SDC_CFG_DTOC, 3);

        host->def_tune_para.iocon = readl(host->base + MSDC_IOCON);
        host->def_tune_para.pad_tune = readl(host->base + MSDC_PAD_TUNE);
        dev_dbg(host->dev, "init hardware done!");
}

static void msdc_deinit_hw(struct msdc_host *host)
{
        u32 val;
        /* Disable and clear all interrupts */
        writel(0, host->base + MSDC_INTEN);

        val = readl(host->base + MSDC_INT);
        writel(val, host->base + MSDC_INT);
}

/* init gpd and bd list in msdc_drv_probe */
static void msdc_init_gpd_bd(struct msdc_host *host, struct msdc_dma *dma)
{
        struct mt_gpdma_desc *gpd = dma->gpd;
        struct mt_bdma_desc *bd = dma->bd;
        int i;

        memset(gpd, 0, sizeof(struct mt_gpdma_desc) * 2);

        gpd->gpd_info = GPDMA_DESC_BDP; /* hwo, cs, bd pointer */
        gpd->ptr = (u32)dma->bd_addr; /* physical address */
        /* gpd->next is must set for desc DMA
         * That's why must alloc 2 gpd structure.
         */
        gpd->next = (u32)dma->gpd_addr + sizeof(struct mt_gpdma_desc);
        memset(bd, 0, sizeof(struct mt_bdma_desc) * MAX_BD_NUM);
        for (i = 0; i < (MAX_BD_NUM - 1); i++)
                bd[i].next = (u32)dma->bd_addr + sizeof(*bd) * (i + 1);
}

static void msdc_ops_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct msdc_host *host = mmc_priv(mmc);
        int ret;

        msdc_set_buswidth(host, ios->bus_width);

        /* Suspend/Resume will do power off/on */
        switch (ios->power_mode) {
        case MMC_POWER_UP:
                if (!IS_ERR(mmc->supply.vmmc)) {
                        msdc_init_hw(host);
                        ret = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
                                        ios->vdd);
                        if (ret) {
                                dev_err(host->dev, "Failed to set vmmc power!\n");
                                return;
                        }
                }
                break;
        case MMC_POWER_ON:
                if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
                        ret = regulator_enable(mmc->supply.vqmmc);
                        if (ret)
                                dev_err(host->dev, "Failed to set vqmmc power!\n");
                        else
                                host->vqmmc_enabled = true;
                }
                break;
        case MMC_POWER_OFF:
                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);

                if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled) {
                        regulator_disable(mmc->supply.vqmmc);
                        host->vqmmc_enabled = false;
                }
                break;
        default:
                break;
        }

        if (host->mclk != ios->clock || host->timing != ios->timing)
                msdc_set_mclk(host, ios->timing, ios->clock);
}

static u32 test_delay_bit(u32 delay, u32 bit)
{
        bit %= PAD_DELAY_MAX;
        return delay & (1 << bit);
}

static int get_delay_len(u32 delay, u32 start_bit)
{
        int i;

        for (i = 0; i < (PAD_DELAY_MAX - start_bit); i++) {
                if (test_delay_bit(delay, start_bit + i) == 0)
                        return i;
        }
        return PAD_DELAY_MAX - start_bit;
}

static struct msdc_delay_phase get_best_delay(struct msdc_host *host, u32 delay)
{
        int start = 0, len = 0;
        int start_final = 0, len_final = 0;
        u8 final_phase = 0xff;
        struct msdc_delay_phase delay_phase = { 0, };

        if (delay == 0) {
                dev_err(host->dev, "phase error: [map:%x]\n", delay);
                delay_phase.final_phase = final_phase;
                return delay_phase;
        }

        while (start < PAD_DELAY_MAX) {
                len = get_delay_len(delay, start);
                if (len_final < len) {
                        start_final = start;
                        len_final = len;
                }
                start += len ? len : 1;
                if (len >= 8 && start_final < 4)
                        break;
        }

        /* The rule is that to find the smallest delay cell */
        if (start_final == 0)
                final_phase = (start_final + len_final / 3) % PAD_DELAY_MAX;
        else
                final_phase = (start_final + len_final / 2) % PAD_DELAY_MAX;
        dev_info(host->dev, "phase: [map:%x] [maxlen:%d] [final:%d]\n",
                 delay, len_final, final_phase);

        delay_phase.maxlen = len_final;
        delay_phase.start = start_final;
        delay_phase.final_phase = final_phase;
        return delay_phase;
}

static int msdc_tune_response(struct mmc_host *mmc, u32 opcode)
{
        struct msdc_host *host = mmc_priv(mmc);
        u32 rise_delay = 0, fall_delay = 0;
        struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,};
        u8 final_delay, final_maxlen;
        int cmd_err;
        int i;

        sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
        for (i = 0 ; i < PAD_DELAY_MAX; i++) {
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_CMDRDLY, i);
                mmc_send_tuning(mmc, opcode, &cmd_err);
                if (!cmd_err)
                        rise_delay |= (1 << i);
        }
        final_rise_delay = get_best_delay(host, rise_delay);
        /* if rising edge has enough margin, then do not scan falling edge */
        if (final_rise_delay.maxlen >= 10 ||
            (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4))
                goto skip_fall;

        sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
        for (i = 0; i < PAD_DELAY_MAX; i++) {
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_CMDRDLY, i);
                mmc_send_tuning(mmc, opcode, &cmd_err);
                if (!cmd_err)
                        fall_delay |= (1 << i);
        }
        final_fall_delay = get_best_delay(host, fall_delay);

skip_fall:
        final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
        if (final_maxlen == final_rise_delay.maxlen) {
                sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
                sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY,
                              final_rise_delay.final_phase);
                final_delay = final_rise_delay.final_phase;
        } else {
                sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
                sdr_set_field(host->base + MSDC_PAD_TUNE, MSDC_PAD_TUNE_CMDRDLY,
                              final_fall_delay.final_phase);
                final_delay = final_fall_delay.final_phase;
        }

        return final_delay == 0xff ? -EIO : 0;
}

static int msdc_tune_data(struct mmc_host *mmc, u32 opcode)
{
        struct msdc_host *host = mmc_priv(mmc);
        u32 rise_delay = 0, fall_delay = 0;
        struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,};
        u8 final_delay, final_maxlen;
        int i, ret;

        sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
        sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
        for (i = 0 ; i < PAD_DELAY_MAX; i++) {
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_DATRRDLY, i);
                ret = mmc_send_tuning(mmc, opcode, NULL);
                if (!ret)
                        rise_delay |= (1 << i);
        }
        final_rise_delay = get_best_delay(host, rise_delay);
        /* if rising edge has enough margin, then do not scan falling edge */
        if (final_rise_delay.maxlen >= 10 ||
            (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4))
                goto skip_fall;

        sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
        sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
        for (i = 0; i < PAD_DELAY_MAX; i++) {
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_DATRRDLY, i);
                ret = mmc_send_tuning(mmc, opcode, NULL);
                if (!ret)
                        fall_delay |= (1 << i);
        }
        final_fall_delay = get_best_delay(host, fall_delay);

skip_fall:
        final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
        if (final_maxlen == final_rise_delay.maxlen) {
                sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
                sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_DATRRDLY,
                              final_rise_delay.final_phase);
                final_delay = final_rise_delay.final_phase;
        } else {
                sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL);
                sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);
                sdr_set_field(host->base + MSDC_PAD_TUNE,
                              MSDC_PAD_TUNE_DATRRDLY,
                              final_fall_delay.final_phase);
                final_delay = final_fall_delay.final_phase;
        }

        return final_delay == 0xff ? -EIO : 0;
}

static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
        struct msdc_host *host = mmc_priv(mmc);
        int ret;

        ret = msdc_tune_response(mmc, opcode);
        if (ret == -EIO) {
                dev_err(host->dev, "Tune response fail!\n");
                return ret;
        }
        if (host->hs400_mode == false) {
                ret = msdc_tune_data(mmc, opcode);
                if (ret == -EIO)
                        dev_err(host->dev, "Tune data fail!\n");
        }

        host->saved_tune_para.iocon = readl(host->base + MSDC_IOCON);
        host->saved_tune_para.pad_tune = readl(host->base + MSDC_PAD_TUNE);
        return ret;
}

static int msdc_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct msdc_host *host = mmc_priv(mmc);
        host->hs400_mode = true;

        writel(host->hs400_ds_delay, host->base + PAD_DS_TUNE);
        return 0;
}

static void msdc_hw_reset(struct mmc_host *mmc)
{
        struct msdc_host *host = mmc_priv(mmc);

        sdr_set_bits(host->base + EMMC_IOCON, 1);
        udelay(10); /* 10us is enough */
        sdr_clr_bits(host->base + EMMC_IOCON, 1);
}

static struct mmc_host_ops mt_msdc_ops = {
        .post_req = msdc_post_req,
        .pre_req = msdc_pre_req,
        .request = msdc_ops_request,
        .set_ios = msdc_ops_set_ios,
        .get_ro = mmc_gpio_get_ro,
        .start_signal_voltage_switch = msdc_ops_switch_volt,
        .card_busy = msdc_card_busy,
        .execute_tuning = msdc_execute_tuning,
        .prepare_hs400_tuning = msdc_prepare_hs400_tuning,
        .hw_reset = msdc_hw_reset,
};

static int msdc_drv_probe(struct platform_device *pdev)
{
        struct mmc_host *mmc;
        struct msdc_host *host;
        struct resource *res;
        int ret;

        if (!pdev->dev.of_node) {
                dev_err(&pdev->dev, "No DT found\n");
                return -EINVAL;
        }
        /* Allocate MMC host for this device */
        mmc = mmc_alloc_host(sizeof(struct msdc_host), &pdev->dev);
        if (!mmc)
                return -ENOMEM;

        host = mmc_priv(mmc);
        ret = mmc_of_parse(mmc);
        if (ret)
                goto host_free;

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

        ret = mmc_regulator_get_supply(mmc);
        if (ret == -EPROBE_DEFER)
                goto host_free;

        host->src_clk = devm_clk_get(&pdev->dev, "source");
        if (IS_ERR(host->src_clk)) {
                ret = PTR_ERR(host->src_clk);
                goto host_free;
        }

        host->h_clk = devm_clk_get(&pdev->dev, "hclk");
        if (IS_ERR(host->h_clk)) {
                ret = PTR_ERR(host->h_clk);
                goto host_free;
        }

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

        host->pinctrl = devm_pinctrl_get(&pdev->dev);
        if (IS_ERR(host->pinctrl)) {
                ret = PTR_ERR(host->pinctrl);
                dev_err(&pdev->dev, "Cannot find pinctrl!\n");
                goto host_free;
        }

        host->pins_default = pinctrl_lookup_state(host->pinctrl, "default");
        if (IS_ERR(host->pins_default)) {
                ret = PTR_ERR(host->pins_default);
                dev_err(&pdev->dev, "Cannot find pinctrl default!\n");
                goto host_free;
        }

        host->pins_uhs = pinctrl_lookup_state(host->pinctrl, "state_uhs");
        if (IS_ERR(host->pins_uhs)) {
                ret = PTR_ERR(host->pins_uhs);
                dev_err(&pdev->dev, "Cannot find pinctrl uhs!\n");
                goto host_free;
        }

        if (!of_property_read_u32(pdev->dev.of_node, "hs400-ds-delay",
                                  &host->hs400_ds_delay))
                dev_dbg(&pdev->dev, "hs400-ds-delay: %x\n",
                        host->hs400_ds_delay);

        host->dev = &pdev->dev;
        host->mmc = mmc;
        host->src_clk_freq = clk_get_rate(host->src_clk);
        /* Set host parameters to mmc */
        mmc->ops = &mt_msdc_ops;
        mmc->f_min = host->src_clk_freq / (4 * 255);

        mmc->caps |= MMC_CAP_ERASE | MMC_CAP_CMD23;
        /* MMC core transfer sizes tunable parameters */
        mmc->max_segs = MAX_BD_NUM;
        mmc->max_seg_size = BDMA_DESC_BUFLEN;
        mmc->max_blk_size = 2048;
        mmc->max_req_size = 512 * 1024;
        mmc->max_blk_count = mmc->max_req_size / 512;
        host->dma_mask = DMA_BIT_MASK(32);
        mmc_dev(mmc)->dma_mask = &host->dma_mask;

        host->timeout_clks = 3 * 1048576;
        host->dma.gpd = dma_alloc_coherent(&pdev->dev,
                                2 * sizeof(struct mt_gpdma_desc),
                                &host->dma.gpd_addr, GFP_KERNEL);
        host->dma.bd = dma_alloc_coherent(&pdev->dev,
                                MAX_BD_NUM * sizeof(struct mt_bdma_desc),
                                &host->dma.bd_addr, GFP_KERNEL);
        if (!host->dma.gpd || !host->dma.bd) {
                ret = -ENOMEM;
                goto release_mem;
        }
        msdc_init_gpd_bd(host, &host->dma);
        INIT_DELAYED_WORK(&host->req_timeout, msdc_request_timeout);
        spin_lock_init(&host->lock);

        platform_set_drvdata(pdev, mmc);
        msdc_ungate_clock(host);
        msdc_init_hw(host);

        ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
                IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
        if (ret)
                goto release;

        pm_runtime_set_active(host->dev);
        pm_runtime_set_autosuspend_delay(host->dev, MTK_MMC_AUTOSUSPEND_DELAY);
        pm_runtime_use_autosuspend(host->dev);
        pm_runtime_enable(host->dev);
        ret = mmc_add_host(mmc);

        if (ret)
                goto end;

        return 0;
end:
        pm_runtime_disable(host->dev);
release:
        platform_set_drvdata(pdev, NULL);
        msdc_deinit_hw(host);
        msdc_gate_clock(host);
release_mem:
        if (host->dma.gpd)
                dma_free_coherent(&pdev->dev,
                        2 * sizeof(struct mt_gpdma_desc),
                        host->dma.gpd, host->dma.gpd_addr);
        if (host->dma.bd)
                dma_free_coherent(&pdev->dev,
                        MAX_BD_NUM * sizeof(struct mt_bdma_desc),
                        host->dma.bd, host->dma.bd_addr);
host_free:
        mmc_free_host(mmc);

        return ret;
}

static int msdc_drv_remove(struct platform_device *pdev)
{
        struct mmc_host *mmc;
        struct msdc_host *host;

        mmc = platform_get_drvdata(pdev);
        host = mmc_priv(mmc);

        pm_runtime_get_sync(host->dev);

        platform_set_drvdata(pdev, NULL);
        mmc_remove_host(host->mmc);
        msdc_deinit_hw(host);
        msdc_gate_clock(host);

        pm_runtime_disable(host->dev);
        pm_runtime_put_noidle(host->dev);
        dma_free_coherent(&pdev->dev,
                        sizeof(struct mt_gpdma_desc),
                        host->dma.gpd, host->dma.gpd_addr);
        dma_free_coherent(&pdev->dev, MAX_BD_NUM * sizeof(struct mt_bdma_desc),
                        host->dma.bd, host->dma.bd_addr);

        mmc_free_host(host->mmc);

        return 0;
}

#ifdef CONFIG_PM
static void msdc_save_reg(struct msdc_host *host)
{
        host->save_para.msdc_cfg = readl(host->base + MSDC_CFG);
        host->save_para.iocon = readl(host->base + MSDC_IOCON);
        host->save_para.sdc_cfg = readl(host->base + SDC_CFG);
        host->save_para.pad_tune = readl(host->base + MSDC_PAD_TUNE);
        host->save_para.patch_bit0 = readl(host->base + MSDC_PATCH_BIT);
        host->save_para.patch_bit1 = readl(host->base + MSDC_PATCH_BIT1);
        host->save_para.pad_ds_tune = readl(host->base + PAD_DS_TUNE);
        host->save_para.emmc50_cfg0 = readl(host->base + EMMC50_CFG0);
}

static void msdc_restore_reg(struct msdc_host *host)
{
        writel(host->save_para.msdc_cfg, host->base + MSDC_CFG);
        writel(host->save_para.iocon, host->base + MSDC_IOCON);
        writel(host->save_para.sdc_cfg, host->base + SDC_CFG);
        writel(host->save_para.pad_tune, host->base + MSDC_PAD_TUNE);
        writel(host->save_para.patch_bit0, host->base + MSDC_PATCH_BIT);
        writel(host->save_para.patch_bit1, host->base + MSDC_PATCH_BIT1);
        writel(host->save_para.pad_ds_tune, host->base + PAD_DS_TUNE);
        writel(host->save_para.emmc50_cfg0, host->base + EMMC50_CFG0);
}

static int msdc_runtime_suspend(struct device *dev)
{
        struct mmc_host *mmc = dev_get_drvdata(dev);
        struct msdc_host *host = mmc_priv(mmc);

        msdc_save_reg(host);
        msdc_gate_clock(host);
        return 0;
}

static int msdc_runtime_resume(struct device *dev)
{
        struct mmc_host *mmc = dev_get_drvdata(dev);
        struct msdc_host *host = mmc_priv(mmc);

        msdc_ungate_clock(host);
        msdc_restore_reg(host);
        return 0;
}
#endif

static const struct dev_pm_ops msdc_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
                                pm_runtime_force_resume)
        SET_RUNTIME_PM_OPS(msdc_runtime_suspend, msdc_runtime_resume, NULL)
};

static const struct of_device_id msdc_of_ids[] = {
        {   .compatible = "mediatek,mt8135-mmc", },
        {}
};

static struct platform_driver mt_msdc_driver = {
        .probe = msdc_drv_probe,
        .remove = msdc_drv_remove,
        .driver = {
                .name = "mtk-msdc",
                .of_match_table = msdc_of_ids,
                .pm = &msdc_dev_pm_ops,
        },
};

module_platform_driver(mt_msdc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MediaTek SD/MMC Card Driver");