// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/mmc/host/mmci.c - ARM PrimeCell MMCI PL180/1 driver
 *
 *  Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved.
 *  Copyright (C) 2010 ST-Ericsson SA
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/log2.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/pm.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sd.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/amba/mmci.h>
#include <linux/pm_runtime.h>
#include <linux/types.h>
#include <linux/pinctrl/consumer.h>
#include <linux/reset.h>
#include <linux/gpio/consumer.h>
#include <linux/workqueue.h>

#include <asm/div64.h>
#include <asm/io.h>

#include "mmci.h"

#define DRIVER_NAME "mmci-pl18x"

static void mmci_variant_init(struct mmci_host *host);
static void ux500_variant_init(struct mmci_host *host);
static void ux500v2_variant_init(struct mmci_host *host);

static unsigned int fmax = 515633;

static struct variant_data variant_arm = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 16,
        .datactrl_blocksz       = 11,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
        .reversed_irq_handling  = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_ROD,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_arm_extended_fifo = {
        .fifosize               = 128 * 4,
        .fifohalfsize           = 64 * 4,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 16,
        .datactrl_blocksz       = 11,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_ROD,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_arm_extended_fifo_hwfc = {
        .fifosize               = 128 * 4,
        .fifohalfsize           = 64 * 4,
        .clkreg_enable          = MCI_ARM_HWFCEN,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 16,
        .datactrl_blocksz       = 11,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_ROD,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_u300 = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg_enable          = MCI_ST_U300_HWFCEN,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 16,
        .datactrl_blocksz       = 11,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                        = true,
        .pwrreg_powerup         = MCI_PWR_ON,
        .f_max                  = 100000000,
        .signal_direction       = true,
        .pwrreg_clkgate         = true,
        .pwrreg_nopower         = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_OD,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_nomadik = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 24,
        .datactrl_blocksz       = 11,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                = true,
        .st_clkdiv              = true,
        .pwrreg_powerup         = MCI_PWR_ON,
        .f_max                  = 100000000,
        .signal_direction       = true,
        .pwrreg_clkgate         = true,
        .pwrreg_nopower         = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_OD,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_ux500 = {
        .fifosize               = 30 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_enable          = MCI_ST_UX500_HWFCEN,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .clkreg_neg_edge_enable = MCI_ST_UX500_NEG_EDGE,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datalength_bits        = 24,
        .datactrl_blocksz       = 11,
        .datactrl_any_blocksz   = true,
        .dma_power_of_2         = true,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                = true,
        .st_clkdiv              = true,
        .pwrreg_powerup         = MCI_PWR_ON,
        .f_max                  = 100000000,
        .signal_direction       = true,
        .pwrreg_clkgate         = true,
        .busy_detect            = true,
        .busy_dpsm_flag         = MCI_DPSM_ST_BUSYMODE,
        .busy_detect_flag       = MCI_ST_CARDBUSY,
        .busy_detect_mask       = MCI_ST_BUSYENDMASK,
        .pwrreg_nopower         = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_OD,
        .init                   = ux500_variant_init,
};

static struct variant_data variant_ux500v2 = {
        .fifosize               = 30 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_enable          = MCI_ST_UX500_HWFCEN,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .clkreg_neg_edge_enable = MCI_ST_UX500_NEG_EDGE,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .datactrl_mask_ddrmode  = MCI_DPSM_ST_DDRMODE,
        .datalength_bits        = 24,
        .datactrl_blocksz       = 11,
        .datactrl_any_blocksz   = true,
        .dma_power_of_2         = true,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                = true,
        .st_clkdiv              = true,
        .pwrreg_powerup         = MCI_PWR_ON,
        .f_max                  = 100000000,
        .signal_direction       = true,
        .pwrreg_clkgate         = true,
        .busy_detect            = true,
        .busy_dpsm_flag         = MCI_DPSM_ST_BUSYMODE,
        .busy_detect_flag       = MCI_ST_CARDBUSY,
        .busy_detect_mask       = MCI_ST_BUSYENDMASK,
        .pwrreg_nopower         = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_OD,
        .init                   = ux500v2_variant_init,
};

static struct variant_data variant_stm32 = {
        .fifosize               = 32 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_enable          = MCI_ST_UX500_HWFCEN,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .clkreg_neg_edge_enable = MCI_ST_UX500_NEG_EDGE,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .datalength_bits        = 24,
        .datactrl_blocksz       = 11,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                = true,
        .st_clkdiv              = true,
        .pwrreg_powerup         = MCI_PWR_ON,
        .f_max                  = 48000000,
        .pwrreg_clkgate         = true,
        .pwrreg_nopower         = true,
        .dma_flow_controller    = true,
        .init                   = mmci_variant_init,
};

static struct variant_data variant_stm32_sdmmc = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .f_max                  = 208000000,
        .stm32_clkdiv           = true,
        .cmdreg_cpsm_enable     = MCI_CPSM_STM32_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_STM32_LRSP_CRC,
        .cmdreg_srsp_crc        = MCI_CPSM_STM32_SRSP_CRC,
        .cmdreg_srsp            = MCI_CPSM_STM32_SRSP,
        .cmdreg_stop            = MCI_CPSM_STM32_CMDSTOP,
        .data_cmd_enable        = MCI_CPSM_STM32_CMDTRANS,
        .irq_pio_mask           = MCI_IRQ_PIO_STM32_MASK,
        .datactrl_first         = true,
        .datacnt_useless        = true,
        .datalength_bits        = 25,
        .datactrl_blocksz       = 14,
        .datactrl_any_blocksz   = true,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .stm32_idmabsize_mask   = GENMASK(12, 5),
        .stm32_idmabsize_align  = BIT(5),
        .supports_sdio_irq      = true,
        .busy_timeout           = true,
        .busy_detect            = true,
        .busy_detect_flag       = MCI_STM32_BUSYD0,
        .busy_detect_mask       = MCI_STM32_BUSYD0ENDMASK,
        .init                   = sdmmc_variant_init,
};

static struct variant_data variant_stm32_sdmmcv2 = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .f_max                  = 267000000,
        .stm32_clkdiv           = true,
        .cmdreg_cpsm_enable     = MCI_CPSM_STM32_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_STM32_LRSP_CRC,
        .cmdreg_srsp_crc        = MCI_CPSM_STM32_SRSP_CRC,
        .cmdreg_srsp            = MCI_CPSM_STM32_SRSP,
        .cmdreg_stop            = MCI_CPSM_STM32_CMDSTOP,
        .data_cmd_enable        = MCI_CPSM_STM32_CMDTRANS,
        .irq_pio_mask           = MCI_IRQ_PIO_STM32_MASK,
        .datactrl_first         = true,
        .datacnt_useless        = true,
        .datalength_bits        = 25,
        .datactrl_blocksz       = 14,
        .datactrl_any_blocksz   = true,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .stm32_idmabsize_mask   = GENMASK(16, 5),
        .stm32_idmabsize_align  = BIT(5),
        .supports_sdio_irq      = true,
        .dma_lli                = true,
        .busy_timeout           = true,
        .busy_detect            = true,
        .busy_detect_flag       = MCI_STM32_BUSYD0,
        .busy_detect_mask       = MCI_STM32_BUSYD0ENDMASK,
        .init                   = sdmmc_variant_init,
};

static struct variant_data variant_stm32_sdmmcv3 = {
        .fifosize               = 256 * 4,
        .fifohalfsize           = 128 * 4,
        .f_max                  = 267000000,
        .stm32_clkdiv           = true,
        .cmdreg_cpsm_enable     = MCI_CPSM_STM32_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_STM32_LRSP_CRC,
        .cmdreg_srsp_crc        = MCI_CPSM_STM32_SRSP_CRC,
        .cmdreg_srsp            = MCI_CPSM_STM32_SRSP,
        .cmdreg_stop            = MCI_CPSM_STM32_CMDSTOP,
        .data_cmd_enable        = MCI_CPSM_STM32_CMDTRANS,
        .irq_pio_mask           = MCI_IRQ_PIO_STM32_MASK,
        .datactrl_first         = true,
        .datacnt_useless        = true,
        .datalength_bits        = 25,
        .datactrl_blocksz       = 14,
        .datactrl_any_blocksz   = true,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .stm32_idmabsize_mask   = GENMASK(16, 6),
        .stm32_idmabsize_align  = BIT(6),
        .supports_sdio_irq      = true,
        .dma_lli                = true,
        .busy_timeout           = true,
        .busy_detect            = true,
        .busy_detect_flag       = MCI_STM32_BUSYD0,
        .busy_detect_mask       = MCI_STM32_BUSYD0ENDMASK,
        .init                   = sdmmc_variant_init,
};

static struct variant_data variant_qcom = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_enable          = MCI_QCOM_CLK_FLOWENA |
                                  MCI_QCOM_CLK_SELECT_IN_FBCLK,
        .clkreg_8bit_bus_enable = MCI_QCOM_CLK_WIDEBUS_8,
        .datactrl_mask_ddrmode  = MCI_QCOM_CLK_SELECT_IN_DDR_MODE,
        .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
        .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
        .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
        .cmdreg_srsp            = MCI_CPSM_RESPONSE,
        .data_cmd_enable        = MCI_CPSM_QCOM_DATCMD,
        .datalength_bits        = 24,
        .datactrl_blocksz       = 11,
        .datactrl_any_blocksz   = true,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 208000000,
        .explicit_mclk_control  = true,
        .qcom_fifo              = true,
        .qcom_dml               = true,
        .mmcimask1              = true,
        .irq_pio_mask           = MCI_IRQ_PIO_MASK,
        .start_err              = MCI_STARTBITERR,
        .opendrain              = MCI_ROD,
        .init                   = qcom_variant_init,
};

/* Busy detection for the ST Micro variant */
static int mmci_card_busy(struct mmc_host *mmc)
{
        struct mmci_host *host = mmc_priv(mmc);
        unsigned long flags;
        int busy = 0;

        spin_lock_irqsave(&host->lock, flags);
        if (readl(host->base + MMCISTATUS) & host->variant->busy_detect_flag)
                busy = 1;
        spin_unlock_irqrestore(&host->lock, flags);

        return busy;
}

static void mmci_reg_delay(struct mmci_host *host)
{
        /*
         * According to the spec, at least three feedback clock cycles
         * of max 52 MHz must pass between two writes to the MMCICLOCK reg.
         * Three MCLK clock cycles must pass between two MMCIPOWER reg writes.
         * Worst delay time during card init is at 100 kHz => 30 us.
         * Worst delay time when up and running is at 25 MHz => 120 ns.
         */
        if (host->cclk < 25000000)
                udelay(30);
        else
                ndelay(120);
}

/*
 * This must be called with host->lock held
 */
void mmci_write_clkreg(struct mmci_host *host, u32 clk)
{
        if (host->clk_reg != clk) {
                host->clk_reg = clk;
                writel(clk, host->base + MMCICLOCK);
        }
}

/*
 * This must be called with host->lock held
 */
void mmci_write_pwrreg(struct mmci_host *host, u32 pwr)
{
        if (host->pwr_reg != pwr) {
                host->pwr_reg = pwr;
                writel(pwr, host->base + MMCIPOWER);
        }
}

/*
 * This must be called with host->lock held
 */
static void mmci_write_datactrlreg(struct mmci_host *host, u32 datactrl)
{
        /* Keep busy mode in DPSM and SDIO mask if enabled */
        datactrl |= host->datactrl_reg & (host->variant->busy_dpsm_flag |
                                          host->variant->datactrl_mask_sdio);

        if (host->datactrl_reg != datactrl) {
                host->datactrl_reg = datactrl;
                writel(datactrl, host->base + MMCIDATACTRL);
        }
}

/*
 * This must be called with host->lock held
 */
static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
{
        struct variant_data *variant = host->variant;
        u32 clk = variant->clkreg;

        /* Make sure cclk reflects the current calculated clock */
        host->cclk = 0;

        if (desired) {
                if (variant->explicit_mclk_control) {
                        host->cclk = host->mclk;
                } else if (desired >= host->mclk) {
                        clk = MCI_CLK_BYPASS;
                        if (variant->st_clkdiv)
                                clk |= MCI_ST_UX500_NEG_EDGE;
                        host->cclk = host->mclk;
                } else if (variant->st_clkdiv) {
                        /*
                         * DB8500 TRM says f = mclk / (clkdiv + 2)
                         * => clkdiv = (mclk / f) - 2
                         * Round the divider up so we don't exceed the max
                         * frequency
                         */
                        clk = DIV_ROUND_UP(host->mclk, desired) - 2;
                        if (clk >= 256)
                                clk = 255;
                        host->cclk = host->mclk / (clk + 2);
                } else {
                        /*
                         * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
                         * => clkdiv = mclk / (2 * f) - 1
                         */
                        clk = host->mclk / (2 * desired) - 1;
                        if (clk >= 256)
                                clk = 255;
                        host->cclk = host->mclk / (2 * (clk + 1));
                }

                clk |= variant->clkreg_enable;
                clk |= MCI_CLK_ENABLE;
                /* This hasn't proven to be worthwhile */
                /* clk |= MCI_CLK_PWRSAVE; */
        }

        /* Set actual clock for debug */
        host->mmc->actual_clock = host->cclk;

        if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
                clk |= MCI_4BIT_BUS;
        if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
                clk |= variant->clkreg_8bit_bus_enable;

        if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50 ||
            host->mmc->ios.timing == MMC_TIMING_MMC_DDR52)
                clk |= variant->clkreg_neg_edge_enable;

        mmci_write_clkreg(host, clk);
}

static void mmci_dma_release(struct mmci_host *host)
{
        if (host->ops && host->ops->dma_release)
                host->ops->dma_release(host);

        host->use_dma = false;
}

static void mmci_dma_setup(struct mmci_host *host)
{
        if (!host->ops || !host->ops->dma_setup)
                return;

        if (host->ops->dma_setup(host))
                return;

        /* initialize pre request cookie */
        host->next_cookie = 1;

        host->use_dma = true;
}

/*
 * Validate mmc prerequisites
 */
static int mmci_validate_data(struct mmci_host *host,
                              struct mmc_data *data)
{
        struct variant_data *variant = host->variant;

        if (!data)
                return 0;
        if (!is_power_of_2(data->blksz) && !variant->datactrl_any_blocksz) {
                dev_err(mmc_dev(host->mmc),
                        "unsupported block size (%d bytes)\n", data->blksz);
                return -EINVAL;
        }

        if (host->ops && host->ops->validate_data)
                return host->ops->validate_data(host, data);

        return 0;
}

static int mmci_prep_data(struct mmci_host *host, struct mmc_data *data, bool next)
{
        int err;

        if (!host->ops || !host->ops->prep_data)
                return 0;

        err = host->ops->prep_data(host, data, next);

        if (next && !err)
                data->host_cookie = ++host->next_cookie < 0 ?
                        1 : host->next_cookie;

        return err;
}

static void mmci_unprep_data(struct mmci_host *host, struct mmc_data *data,
                      int err)
{
        if (host->ops && host->ops->unprep_data)
                host->ops->unprep_data(host, data, err);

        data->host_cookie = 0;
}

static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
        WARN_ON(data->host_cookie && data->host_cookie != host->next_cookie);

        if (host->ops && host->ops->get_next_data)
                host->ops->get_next_data(host, data);
}

static int mmci_dma_start(struct mmci_host *host, unsigned int datactrl)
{
        struct mmc_data *data = host->data;
        int ret;

        if (!host->use_dma)
                return -EINVAL;

        ret = mmci_prep_data(host, data, false);
        if (ret)
                return ret;

        if (!host->ops || !host->ops->dma_start)
                return -EINVAL;

        /* Okay, go for it. */
        dev_vdbg(mmc_dev(host->mmc),
                 "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
                 data->sg_len, data->blksz, data->blocks, data->flags);

        ret = host->ops->dma_start(host, &datactrl);
        if (ret)
                return ret;

        /* Trigger the DMA transfer */
        mmci_write_datactrlreg(host, datactrl);

        /*
         * Let the MMCI say when the data is ended and it's time
         * to fire next DMA request. When that happens, MMCI will
         * call mmci_data_end()
         */
        writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
               host->base + MMCIMASK0);
        return 0;
}

static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
{
        if (!host->use_dma)
                return;

        if (host->ops && host->ops->dma_finalize)
                host->ops->dma_finalize(host, data);
}

static void mmci_dma_error(struct mmci_host *host)
{
        if (!host->use_dma)
                return;

        if (host->ops && host->ops->dma_error)
                host->ops->dma_error(host);
}

static void
mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
{
        writel(0, host->base + MMCICOMMAND);

        BUG_ON(host->data);

        host->mrq = NULL;
        host->cmd = NULL;

        mmc_request_done(host->mmc, mrq);
}

static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
{
        void __iomem *base = host->base;
        struct variant_data *variant = host->variant;

        if (host->singleirq) {
                unsigned int mask0 = readl(base + MMCIMASK0);

                mask0 &= ~variant->irq_pio_mask;
                mask0 |= mask;

                writel(mask0, base + MMCIMASK0);
        }

        if (variant->mmcimask1)
                writel(mask, base + MMCIMASK1);

        host->mask1_reg = mask;
}

static void mmci_stop_data(struct mmci_host *host)
{
        mmci_write_datactrlreg(host, 0);
        mmci_set_mask1(host, 0);
        host->data = NULL;
}

static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
{
        unsigned int flags = SG_MITER_ATOMIC;

        if (data->flags & MMC_DATA_READ)
                flags |= SG_MITER_TO_SG;
        else
                flags |= SG_MITER_FROM_SG;

        sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
}

static u32 mmci_get_dctrl_cfg(struct mmci_host *host)
{
        return MCI_DPSM_ENABLE | mmci_dctrl_blksz(host);
}

static u32 ux500v2_get_dctrl_cfg(struct mmci_host *host)
{
        return MCI_DPSM_ENABLE | (host->data->blksz << 16);
}

static void ux500_busy_clear_mask_done(struct mmci_host *host)
{
        void __iomem *base = host->base;

        writel(host->variant->busy_detect_mask, base + MMCICLEAR);
        writel(readl(base + MMCIMASK0) &
               ~host->variant->busy_detect_mask, base + MMCIMASK0);
        host->busy_state = MMCI_BUSY_DONE;
        host->busy_status = 0;
}

/*
 * ux500_busy_complete() - this will wait until the busy status
 * goes off, saving any status that occur in the meantime into
 * host->busy_status until we know the card is not busy any more.
 * The function returns true when the busy detection is ended
 * and we should continue processing the command.
 *
 * The Ux500 typically fires two IRQs over a busy cycle like this:
 *
 *  DAT0 busy          +-----------------+
 *                     |                 |
 *  DAT0 not busy  ----+                 +--------
 *
 *                     ^                 ^
 *                     |                 |
 *                    IRQ1              IRQ2
 */
static bool ux500_busy_complete(struct mmci_host *host, struct mmc_command *cmd,
                                u32 status, u32 err_msk)
{
        void __iomem *base = host->base;
        int retries = 10;

        if (status & err_msk) {
                /* Stop any ongoing busy detection if an error occurs */
                ux500_busy_clear_mask_done(host);
                goto out_ret_state;
        }

        /*
         * The state transitions are encoded in a state machine crossing
         * the edges in this switch statement.
         */
        switch (host->busy_state) {

        /*
         * Before unmasking for the busy end IRQ, confirm that the
         * command was sent successfully. To keep track of having a
         * command in-progress, waiting for busy signaling to end,
         * store the status in host->busy_status.
         *
         * Note that, the card may need a couple of clock cycles before
         * it starts signaling busy on DAT0, hence re-read the
         * MMCISTATUS register here, to allow the busy bit to be set.
         */
        case MMCI_BUSY_DONE:
                /*
                 * Save the first status register read to be sure to catch
                 * all bits that may be lost will retrying. If the command
                 * is still busy this will result in assigning 0 to
                 * host->busy_status, which is what it should be in IDLE.
                 */
                host->busy_status = status & (MCI_CMDSENT | MCI_CMDRESPEND);
                while (retries) {
                        status = readl(base + MMCISTATUS);
                        /* Keep accumulating status bits */
                        host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
                        if (status & host->variant->busy_detect_flag) {
                                writel(readl(base + MMCIMASK0) |
                                       host->variant->busy_detect_mask,
                                       base + MMCIMASK0);
                                host->busy_state = MMCI_BUSY_WAITING_FOR_START_IRQ;
                                schedule_delayed_work(&host->ux500_busy_timeout_work,
                                      msecs_to_jiffies(cmd->busy_timeout));
                                goto out_ret_state;
                        }
                        retries--;
                }
                dev_dbg(mmc_dev(host->mmc),
                        "no busy signalling in time CMD%02x\n", cmd->opcode);
                ux500_busy_clear_mask_done(host);
                break;

        /*
         * If there is a command in-progress that has been successfully
         * sent, then bail out if busy status is set and wait for the
         * busy end IRQ.
         *
         * Note that, the HW triggers an IRQ on both edges while
         * monitoring DAT0 for busy completion, but there is only one
         * status bit in MMCISTATUS for the busy state. Therefore
         * both the start and the end interrupts needs to be cleared,
         * one after the other. So, clear the busy start IRQ here.
         */
        case MMCI_BUSY_WAITING_FOR_START_IRQ:
                if (status & host->variant->busy_detect_flag) {
                        host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
                        writel(host->variant->busy_detect_mask, base + MMCICLEAR);
                        host->busy_state = MMCI_BUSY_WAITING_FOR_END_IRQ;
                } else {
                        dev_dbg(mmc_dev(host->mmc),
                                "lost busy status when waiting for busy start IRQ CMD%02x\n",
                                cmd->opcode);
                        cancel_delayed_work(&host->ux500_busy_timeout_work);
                        ux500_busy_clear_mask_done(host);
                }
                break;

        case MMCI_BUSY_WAITING_FOR_END_IRQ:
                if (!(status & host->variant->busy_detect_flag)) {
                        host->busy_status |= status & (MCI_CMDSENT | MCI_CMDRESPEND);
                        writel(host->variant->busy_detect_mask, base + MMCICLEAR);
                        cancel_delayed_work(&host->ux500_busy_timeout_work);
                        ux500_busy_clear_mask_done(host);
                } else {
                        dev_dbg(mmc_dev(host->mmc),
                                "busy status still asserted when handling busy end IRQ - will keep waiting CMD%02x\n",
                                cmd->opcode);
                }
                break;

        default:
                dev_dbg(mmc_dev(host->mmc), "fell through on state %d, CMD%02x\n",
                        host->busy_state, cmd->opcode);
                break;
        }

out_ret_state:
        return (host->busy_state == MMCI_BUSY_DONE);
}

/*
 * All the DMA operation mode stuff goes inside this ifdef.
 * This assumes that you have a generic DMA device interface,
 * no custom DMA interfaces are supported.
 */
#ifdef CONFIG_DMA_ENGINE
struct mmci_dmae_next {
        struct dma_async_tx_descriptor *desc;
        struct dma_chan *chan;
};

struct mmci_dmae_priv {
        struct dma_chan *cur;
        struct dma_chan *rx_channel;
        struct dma_chan *tx_channel;
        struct dma_async_tx_descriptor  *desc_current;
        struct mmci_dmae_next next_data;
};

int mmci_dmae_setup(struct mmci_host *host)
{
        const char *rxname, *txname;
        struct mmci_dmae_priv *dmae;

        dmae = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dmae), GFP_KERNEL);
        if (!dmae)
                return -ENOMEM;

        host->dma_priv = dmae;

        dmae->rx_channel = dma_request_chan(mmc_dev(host->mmc), "rx");
        if (IS_ERR(dmae->rx_channel)) {
                int ret = PTR_ERR(dmae->rx_channel);
                dmae->rx_channel = NULL;
                return ret;
        }

        dmae->tx_channel = dma_request_chan(mmc_dev(host->mmc), "tx");
        if (IS_ERR(dmae->tx_channel)) {
                if (PTR_ERR(dmae->tx_channel) == -EPROBE_DEFER)
                        dev_warn(mmc_dev(host->mmc),
                                 "Deferred probe for TX channel ignored\n");
                dmae->tx_channel = NULL;
        }

        /*
         * If only an RX channel is specified, the driver will
         * attempt to use it bidirectionally, however if it
         * is specified but cannot be located, DMA will be disabled.
         */
        if (dmae->rx_channel && !dmae->tx_channel)
                dmae->tx_channel = dmae->rx_channel;

        if (dmae->rx_channel)
                rxname = dma_chan_name(dmae->rx_channel);
        else
                rxname = "none";

        if (dmae->tx_channel)
                txname = dma_chan_name(dmae->tx_channel);
        else
                txname = "none";

        dev_info(mmc_dev(host->mmc), "DMA channels RX %s, TX %s\n",
                 rxname, txname);

        /*
         * Limit the maximum segment size in any SG entry according to
         * the parameters of the DMA engine device.
         */
        if (dmae->tx_channel) {
                struct device *dev = dmae->tx_channel->device->dev;
                unsigned int max_seg_size = dma_get_max_seg_size(dev);

                if (max_seg_size < host->mmc->max_seg_size)
                        host->mmc->max_seg_size = max_seg_size;
        }
        if (dmae->rx_channel) {
                struct device *dev = dmae->rx_channel->device->dev;
                unsigned int max_seg_size = dma_get_max_seg_size(dev);

                if (max_seg_size < host->mmc->max_seg_size)
                        host->mmc->max_seg_size = max_seg_size;
        }

        if (!dmae->tx_channel || !dmae->rx_channel) {
                mmci_dmae_release(host);
                return -EINVAL;
        }

        return 0;
}

/*
 * This is used in or so inline it
 * so it can be discarded.
 */
void mmci_dmae_release(struct mmci_host *host)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;

        if (dmae->rx_channel)
                dma_release_channel(dmae->rx_channel);
        if (dmae->tx_channel)
                dma_release_channel(dmae->tx_channel);
        dmae->rx_channel = dmae->tx_channel = NULL;
}

static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        struct dma_chan *chan;

        if (data->flags & MMC_DATA_READ)
                chan = dmae->rx_channel;
        else
                chan = dmae->tx_channel;

        dma_unmap_sg(chan->device->dev, data->sg, data->sg_len,
                     mmc_get_dma_dir(data));
}

void mmci_dmae_error(struct mmci_host *host)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;

        if (!dma_inprogress(host))
                return;

        dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
        dmaengine_terminate_all(dmae->cur);
        host->dma_in_progress = false;
        dmae->cur = NULL;
        dmae->desc_current = NULL;
        host->data->host_cookie = 0;

        mmci_dma_unmap(host, host->data);
}

void mmci_dmae_finalize(struct mmci_host *host, struct mmc_data *data)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        u32 status;
        int i;

        if (!dma_inprogress(host))
                return;

        /* Wait up to 1ms for the DMA to complete */
        for (i = 0; ; i++) {
                status = readl(host->base + MMCISTATUS);
                if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
                        break;
                udelay(10);
        }

        /*
         * Check to see whether we still have some data left in the FIFO -
         * this catches DMA controllers which are unable to monitor the
         * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
         * contiguous buffers.  On TX, we'll get a FIFO underrun error.
         */
        if (status & MCI_RXDATAAVLBLMASK) {
                mmci_dma_error(host);
                if (!data->error)
                        data->error = -EIO;
        } else if (!data->host_cookie) {
                mmci_dma_unmap(host, data);
        }

        /*
         * Use of DMA with scatter-gather is impossible.
         * Give up with DMA and switch back to PIO mode.
         */
        if (status & MCI_RXDATAAVLBLMASK) {
                dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
                mmci_dma_release(host);
        }

        host->dma_in_progress = false;
        dmae->cur = NULL;
        dmae->desc_current = NULL;
}

/* prepares DMA channel and DMA descriptor, returns non-zero on failure */
static int _mmci_dmae_prep_data(struct mmci_host *host, struct mmc_data *data,
                                struct dma_chan **dma_chan,
                                struct dma_async_tx_descriptor **dma_desc)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        struct variant_data *variant = host->variant;
        struct dma_slave_config conf = {
                .src_addr = host->phybase + MMCIFIFO,
                .dst_addr = host->phybase + MMCIFIFO,
                .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
                .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
                .src_maxburst = variant->fifohalfsize >> 2, /* # of words */
                .dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
                .device_fc = variant->dma_flow_controller,
        };
        struct dma_chan *chan;
        struct dma_device *device;
        struct dma_async_tx_descriptor *desc;
        int nr_sg;
        unsigned long flags = DMA_CTRL_ACK;

        if (data->flags & MMC_DATA_READ) {
                conf.direction = DMA_DEV_TO_MEM;
                chan = dmae->rx_channel;
        } else {
                conf.direction = DMA_MEM_TO_DEV;
                chan = dmae->tx_channel;
        }

        /* If there's no DMA channel, fall back to PIO */
        if (!chan)
                return -EINVAL;

        /* If less than or equal to the fifo size, don't bother with DMA */
        if (data->blksz * data->blocks <= variant->fifosize)
                return -EINVAL;

        /*
         * This is necessary to get SDIO working on the Ux500. We do not yet
         * know if this is a bug in:
         * - The Ux500 DMA controller (DMA40)
         * - The MMCI DMA interface on the Ux500
         * some power of two blocks (such as 64 bytes) are sent regularly
         * during SDIO traffic and those work fine so for these we enable DMA
         * transfers.
         */
        if (host->variant->dma_power_of_2 && !is_power_of_2(data->blksz))
                return -EINVAL;

        device = chan->device;
        nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len,
                           mmc_get_dma_dir(data));
        if (nr_sg == 0)
                return -EINVAL;

        if (host->variant->qcom_dml)
                flags |= DMA_PREP_INTERRUPT;

        dmaengine_slave_config(chan, &conf);
        desc = dmaengine_prep_slave_sg(chan, data->sg, nr_sg,
                                            conf.direction, flags);
        if (!desc)
                goto unmap_exit;

        *dma_chan = chan;
        *dma_desc = desc;

        return 0;

 unmap_exit:
        dma_unmap_sg(device->dev, data->sg, data->sg_len,
                     mmc_get_dma_dir(data));
        return -ENOMEM;
}

int mmci_dmae_prep_data(struct mmci_host *host,
                        struct mmc_data *data,
                        bool next)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        struct mmci_dmae_next *nd = &dmae->next_data;

        if (!host->use_dma)
                return -EINVAL;

        if (next)
                return _mmci_dmae_prep_data(host, data, &nd->chan, &nd->desc);
        /* Check if next job is already prepared. */
        if (dmae->cur && dmae->desc_current)
                return 0;

        /* No job were prepared thus do it now. */
        return _mmci_dmae_prep_data(host, data, &dmae->cur,
                                    &dmae->desc_current);
}

int mmci_dmae_start(struct mmci_host *host, unsigned int *datactrl)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        int ret;

        host->dma_in_progress = true;
        ret = dma_submit_error(dmaengine_submit(dmae->desc_current));
        if (ret < 0) {
                host->dma_in_progress = false;
                return ret;
        }
        dma_async_issue_pending(dmae->cur);

        *datactrl |= MCI_DPSM_DMAENABLE;

        return 0;
}

void mmci_dmae_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
        struct mmci_dmae_priv *dmae = host->dma_priv;
        struct mmci_dmae_next *next = &dmae->next_data;

        if (!host->use_dma)
                return;

        WARN_ON(!data->host_cookie && (next->desc || next->chan));

        dmae->desc_current = next->desc;
        dmae->cur = next->chan;
        next->desc = NULL;
        next->chan = NULL;
}

void mmci_dmae_unprep_data(struct mmci_host *host,
                           struct mmc_data *data, int err)

{
        struct mmci_dmae_priv *dmae = host->dma_priv;

        if (!host->use_dma)
                return;

        mmci_dma_unmap(host, data);

        if (err) {
                struct mmci_dmae_next *next = &dmae->next_data;
                struct dma_chan *chan;
                if (data->flags & MMC_DATA_READ)
                        chan = dmae->rx_channel;
                else
                        chan = dmae->tx_channel;
                dmaengine_terminate_all(chan);

                if (dmae->desc_current == next->desc)
                        dmae->desc_current = NULL;

                if (dmae->cur == next->chan) {
                        host->dma_in_progress = false;
                        dmae->cur = NULL;
                }

                next->desc = NULL;
                next->chan = NULL;
        }
}

static struct mmci_host_ops mmci_variant_ops = {
        .prep_data = mmci_dmae_prep_data,
        .unprep_data = mmci_dmae_unprep_data,
        .get_datactrl_cfg = mmci_get_dctrl_cfg,
        .get_next_data = mmci_dmae_get_next_data,
        .dma_setup = mmci_dmae_setup,
        .dma_release = mmci_dmae_release,
        .dma_start = mmci_dmae_start,
        .dma_finalize = mmci_dmae_finalize,
        .dma_error = mmci_dmae_error,
};
#else
static struct mmci_host_ops mmci_variant_ops = {
        .get_datactrl_cfg = mmci_get_dctrl_cfg,
};
#endif

static void mmci_variant_init(struct mmci_host *host)
{
        host->ops = &mmci_variant_ops;
}

static void ux500_variant_init(struct mmci_host *host)
{
        host->ops = &mmci_variant_ops;
        host->ops->busy_complete = ux500_busy_complete;
}

static void ux500v2_variant_init(struct mmci_host *host)
{
        host->ops = &mmci_variant_ops;
        host->ops->busy_complete = ux500_busy_complete;
        host->ops->get_datactrl_cfg = ux500v2_get_dctrl_cfg;
}

static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct mmci_host *host = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!data)
                return;

        WARN_ON(data->host_cookie);

        if (mmci_validate_data(host, data))
                return;

        mmci_prep_data(host, data, true);
}

static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
                              int err)
{
        struct mmci_host *host = mmc_priv(mmc);
        struct mmc_data *data = mrq->data;

        if (!data || !data->host_cookie)
                return;

        mmci_unprep_data(host, data, err);
}

static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
        struct variant_data *variant = host->variant;
        unsigned int datactrl, timeout, irqmask;
        unsigned long long clks;
        void __iomem *base;

        dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
                data->blksz, data->blocks, data->flags);

        host->data = data;
        host->size = data->blksz * data->blocks;
        data->bytes_xfered = 0;

        clks = (unsigned long long)data->timeout_ns * host->cclk;
        do_div(clks, NSEC_PER_SEC);

        timeout = data->timeout_clks + (unsigned int)clks;

        base = host->base;
        writel(timeout, base + MMCIDATATIMER);
        writel(host->size, base + MMCIDATALENGTH);

        datactrl = host->ops->get_datactrl_cfg(host);
        datactrl |= host->data->flags & MMC_DATA_READ ? MCI_DPSM_DIRECTION : 0;

        if (host->mmc->card && mmc_card_sdio(host->mmc->card)) {
                u32 clk;

                datactrl |= variant->datactrl_mask_sdio;

                /*
                 * The ST Micro variant for SDIO small write transfers
                 * needs to have clock H/W flow control disabled,
                 * otherwise the transfer will not start. The threshold
                 * depends on the rate of MCLK.
                 */
                if (variant->st_sdio && data->flags & MMC_DATA_WRITE &&
                    (host->size < 8 ||
                     (host->size <= 8 && host->mclk > 50000000)))
                        clk = host->clk_reg & ~variant->clkreg_enable;
                else
                        clk = host->clk_reg | variant->clkreg_enable;

                mmci_write_clkreg(host, clk);
        }

        if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50 ||
            host->mmc->ios.timing == MMC_TIMING_MMC_DDR52)
                datactrl |= variant->datactrl_mask_ddrmode;

        /*
         * Attempt to use DMA operation mode, if this
         * should fail, fall back to PIO mode
         */
        if (!mmci_dma_start(host, datactrl))
                return;

        /* IRQ mode, map the SG list for CPU reading/writing */
        mmci_init_sg(host, data);

        if (data->flags & MMC_DATA_READ) {
                irqmask = MCI_RXFIFOHALFFULLMASK;

                /*
                 * If we have less than the fifo 'half-full' threshold to
                 * transfer, trigger a PIO interrupt as soon as any data
                 * is available.
                 */
                if (host->size < variant->fifohalfsize)
                        irqmask |= MCI_RXDATAAVLBLMASK;
        } else {
                /*
                 * We don't actually need to include "FIFO empty" here
                 * since its implicit in "FIFO half empty".
                 */
                irqmask = MCI_TXFIFOHALFEMPTYMASK;
        }

        mmci_write_datactrlreg(host, datactrl);
        writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
        mmci_set_mask1(host, irqmask);
}

static void
mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
{
        void __iomem *base = host->base;
        bool busy_resp = cmd->flags & MMC_RSP_BUSY;
        unsigned long long clks;

        dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
            cmd->opcode, cmd->arg, cmd->flags);

        if (readl(base + MMCICOMMAND) & host->variant->cmdreg_cpsm_enable) {
                writel(0, base + MMCICOMMAND);
                mmci_reg_delay(host);
        }

        if (host->variant->cmdreg_stop &&
            cmd->opcode == MMC_STOP_TRANSMISSION)
                c |= host->variant->cmdreg_stop;

        c |= cmd->opcode | host->variant->cmdreg_cpsm_enable;
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136)
                        c |= host->variant->cmdreg_lrsp_crc;
                else if (cmd->flags & MMC_RSP_CRC)
                        c |= host->variant->cmdreg_srsp_crc;
                else
                        c |= host->variant->cmdreg_srsp;
        }

        host->busy_status = 0;
        host->busy_state = MMCI_BUSY_DONE;

        /* Assign a default timeout if the core does not provide one */
        if (busy_resp && !cmd->busy_timeout)
                cmd->busy_timeout = 10 * MSEC_PER_SEC;

        if (busy_resp && host->variant->busy_timeout) {
                if (cmd->busy_timeout > host->mmc->max_busy_timeout)
                        clks = (unsigned long long)host->mmc->max_busy_timeout * host->cclk;
                else
                        clks = (unsigned long long)cmd->busy_timeout * host->cclk;

                do_div(clks, MSEC_PER_SEC);
                writel_relaxed(clks, host->base + MMCIDATATIMER);
        }

        if (host->ops->pre_sig_volt_switch && cmd->opcode == SD_SWITCH_VOLTAGE)
                host->ops->pre_sig_volt_switch(host);

        if (/*interrupt*/0)
                c |= MCI_CPSM_INTERRUPT;

        if (mmc_cmd_type(cmd) == MMC_CMD_ADTC)
                c |= host->variant->data_cmd_enable;

        host->cmd = cmd;

        writel(cmd->arg, base + MMCIARGUMENT);
        writel(c, base + MMCICOMMAND);
}

static void mmci_stop_command(struct mmci_host *host)
{
        host->stop_abort.error = 0;
        mmci_start_command(host, &host->stop_abort, 0);
}

static void
mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
              unsigned int status)
{
        unsigned int status_err;

        /* Make sure we have data to handle */
        if (!data)
                return;

        /* First check for errors */
        status_err = status & (host->variant->start_err |
                               MCI_DATACRCFAIL | MCI_DATATIMEOUT |
                               MCI_TXUNDERRUN | MCI_RXOVERRUN);

        if (status_err) {
                u32 remain, success;

                /* Terminate the DMA transfer */
                mmci_dma_error(host);

                /*
                 * Calculate how far we are into the transfer.  Note that
                 * the data counter gives the number of bytes transferred
                 * on the MMC bus, not on the host side.  On reads, this
                 * can be as much as a FIFO-worth of data ahead.  This
                 * matters for FIFO overruns only.
                 */
                if (!host->variant->datacnt_useless) {
                        remain = readl(host->base + MMCIDATACNT);
                        success = data->blksz * data->blocks - remain;
                } else {
                        success = 0;
                }

                dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
                        status_err, success);
                if (status_err & MCI_DATACRCFAIL) {
                        /* Last block was not successful */
                        success -= 1;
                        data->error = -EILSEQ;
                } else if (status_err & MCI_DATATIMEOUT) {
                        data->error = -ETIMEDOUT;
                } else if (status_err & MCI_STARTBITERR) {
                        data->error = -ECOMM;
                } else if (status_err & MCI_TXUNDERRUN) {
                        data->error = -EIO;
                } else if (status_err & MCI_RXOVERRUN) {
                        if (success > host->variant->fifosize)
                                success -= host->variant->fifosize;
                        else
                                success = 0;
                        data->error = -EIO;
                }
                data->bytes_xfered = round_down(success, data->blksz);
        }

        if (status & MCI_DATABLOCKEND)
                dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");

        if (status & MCI_DATAEND || data->error) {
                mmci_dma_finalize(host, data);

                mmci_stop_data(host);

                if (!data->error)
                        /* The error clause is handled above, success! */
                        data->bytes_xfered = data->blksz * data->blocks;

                if (!data->stop) {
                        if (host->variant->cmdreg_stop && data->error)
                                mmci_stop_command(host);
                        else
                                mmci_request_end(host, data->mrq);
                } else if (host->mrq->sbc && !data->error) {
                        mmci_request_end(host, data->mrq);
                } else {
                        mmci_start_command(host, data->stop, 0);
                }
        }
}

static void
mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
             unsigned int status)
{
        u32 err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT;
        void __iomem *base = host->base;
        bool sbc, busy_resp;

        if (!cmd)
                return;

        sbc = (cmd == host->mrq->sbc);
        busy_resp = !!(cmd->flags & MMC_RSP_BUSY);

        /*
         * We need to be one of these interrupts to be considered worth
         * handling. Note that we tag on any latent IRQs postponed
         * due to waiting for busy status.
         */
        if (host->variant->busy_timeout && busy_resp)
                err_msk |= MCI_DATATIMEOUT;

        if (!((status | host->busy_status) &
              (err_msk | MCI_CMDSENT | MCI_CMDRESPEND)))
                return;

        /* Handle busy detection on DAT0 if the variant supports it. */
        if (busy_resp && host->variant->busy_detect)
                if (!host->ops->busy_complete(host, cmd, status, err_msk))
                        return;

        host->cmd = NULL;

        if (status & MCI_CMDTIMEOUT) {
                cmd->error = -ETIMEDOUT;
        } else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
                cmd->error = -EILSEQ;
        } else if (host->variant->busy_timeout && busy_resp &&
                   status & MCI_DATATIMEOUT) {
                cmd->error = -ETIMEDOUT;
                /*
                 * This will wake up mmci_irq_thread() which will issue
                 * a hardware reset of the MMCI block.
                 */
                host->irq_action = IRQ_WAKE_THREAD;
        } else {
                cmd->resp[0] = readl(base + MMCIRESPONSE0);
                cmd->resp[1] = readl(base + MMCIRESPONSE1);
                cmd->resp[2] = readl(base + MMCIRESPONSE2);
                cmd->resp[3] = readl(base + MMCIRESPONSE3);
        }

        if ((!sbc && !cmd->data) || cmd->error) {
                if (host->data) {
                        /* Terminate the DMA transfer */
                        mmci_dma_error(host);

                        mmci_stop_data(host);
                        if (host->variant->cmdreg_stop && cmd->error) {
                                mmci_stop_command(host);
                                return;
                        }
                }

                if (host->irq_action != IRQ_WAKE_THREAD)
                        mmci_request_end(host, host->mrq);

        } else if (sbc) {
                mmci_start_command(host, host->mrq->cmd, 0);
        } else if (!host->variant->datactrl_first &&
                   !(cmd->data->flags & MMC_DATA_READ)) {
                mmci_start_data(host, cmd->data);
        }
}

static char *ux500_state_str(struct mmci_host *host)
{
        switch (host->busy_state) {
        case MMCI_BUSY_WAITING_FOR_START_IRQ:
                return "waiting for start IRQ";
        case MMCI_BUSY_WAITING_FOR_END_IRQ:
                return "waiting for end IRQ";
        case MMCI_BUSY_DONE:
                return "not waiting for IRQs";
        default:
                return "unknown";
        }
}

/*
 * This busy timeout worker is used to "kick" the command IRQ if a
 * busy detect IRQ fails to appear in reasonable time. Only used on
 * variants with busy detection IRQ delivery.
 */
static void ux500_busy_timeout_work(struct work_struct *work)
{
        struct mmci_host *host = container_of(work, struct mmci_host,
                                        ux500_busy_timeout_work.work);
        unsigned long flags;
        u32 status;

        spin_lock_irqsave(&host->lock, flags);

        if (host->cmd) {
                /* If we are still busy let's tag on a cmd-timeout error. */
                status = readl(host->base + MMCISTATUS);
                if (status & host->variant->busy_detect_flag) {
                        status |= MCI_CMDTIMEOUT;
                        dev_err(mmc_dev(host->mmc),
                                "timeout in state %s still busy with CMD%02x\n",
                                ux500_state_str(host), host->cmd->opcode);
                } else {
                        dev_err(mmc_dev(host->mmc),
                                "timeout in state %s waiting for busy CMD%02x\n",
                                ux500_state_str(host), host->cmd->opcode);
                }

                mmci_cmd_irq(host, host->cmd, status);
        }

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

static int mmci_get_rx_fifocnt(struct mmci_host *host, u32 status, int remain)
{
        return remain - (readl(host->base + MMCIFIFOCNT) << 2);
}

static int mmci_qcom_get_rx_fifocnt(struct mmci_host *host, u32 status, int r)
{
        /*
         * on qcom SDCC4 only 8 words are used in each burst so only 8 addresses
         * from the fifo range should be used
         */
        if (status & MCI_RXFIFOHALFFULL)
                return host->variant->fifohalfsize;
        else if (status & MCI_RXDATAAVLBL)
                return 4;

        return 0;
}

static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
{
        void __iomem *base = host->base;
        char *ptr = buffer;
        u32 status = readl(host->base + MMCISTATUS);
        int host_remain = host->size;

        do {
                int count = host->get_rx_fifocnt(host, status, host_remain);

                if (count > remain)
                        count = remain;

                if (count <= 0)
                        break;

                /*
                 * SDIO especially may want to send something that is
                 * not divisible by 4 (as opposed to card sectors
                 * etc). Therefore make sure to always read the last bytes
                 * while only doing full 32-bit reads towards the FIFO.
                 */
                if (unlikely(count & 0x3)) {
                        if (count < 4) {
                                unsigned char buf[4];
                                ioread32_rep(base + MMCIFIFO, buf, 1);
                                memcpy(ptr, buf, count);
                        } else {
                                ioread32_rep(base + MMCIFIFO, ptr, count >> 2);
                                count &= ~0x3;
                        }
                } else {
                        ioread32_rep(base + MMCIFIFO, ptr, count >> 2);
                }

                ptr += count;
                remain -= count;
                host_remain -= count;

                if (remain == 0)
                        break;

                status = readl(base + MMCISTATUS);
        } while (status & MCI_RXDATAAVLBL);

        return ptr - buffer;
}

static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
{
        struct variant_data *variant = host->variant;
        void __iomem *base = host->base;
        char *ptr = buffer;

        do {
                unsigned int count, maxcnt;

                maxcnt = status & MCI_TXFIFOEMPTY ?
                         variant->fifosize : variant->fifohalfsize;
                count = min(remain, maxcnt);

                /*
                 * SDIO especially may want to send something that is
                 * not divisible by 4 (as opposed to card sectors
                 * etc), and the FIFO only accept full 32-bit writes.
                 * So compensate by adding +3 on the count, a single
                 * byte become a 32bit write, 7 bytes will be two
                 * 32bit writes etc.
                 */
                iowrite32_rep(base + MMCIFIFO, ptr, (count + 3) >> 2);

                ptr += count;
                remain -= count;

                if (remain == 0)
                        break;

                status = readl(base + MMCISTATUS);
        } while (status & MCI_TXFIFOHALFEMPTY);

        return ptr - buffer;
}

/*
 * PIO data transfer IRQ handler.
 */
static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
{
        struct mmci_host *host = dev_id;
        struct sg_mapping_iter *sg_miter = &host->sg_miter;
        struct variant_data *variant = host->variant;
        void __iomem *base = host->base;
        u32 status;

        status = readl(base + MMCISTATUS);

        dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);

        do {
                unsigned int remain, len;
                char *buffer;

                /*
                 * For write, we only need to test the half-empty flag
                 * here - if the FIFO is completely empty, then by
                 * definition it is more than half empty.
                 *
                 * For read, check for data available.
                 */
                if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
                        break;

                if (!sg_miter_next(sg_miter))
                        break;

                buffer = sg_miter->addr;
                remain = sg_miter->length;

                len = 0;
                if (status & MCI_RXACTIVE)
                        len = mmci_pio_read(host, buffer, remain);
                if (status & MCI_TXACTIVE)
                        len = mmci_pio_write(host, buffer, remain, status);

                sg_miter->consumed = len;

                host->size -= len;
                remain -= len;

                if (remain)
                        break;

                status = readl(base + MMCISTATUS);
        } while (1);

        sg_miter_stop(sg_miter);

        /*
         * If we have less than the fifo 'half-full' threshold to transfer,
         * trigger a PIO interrupt as soon as any data is available.
         */
        if (status & MCI_RXACTIVE && host->size < variant->fifohalfsize)
                mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);

        /*
         * If we run out of data, disable the data IRQs; this
         * prevents a race where the FIFO becomes empty before
         * the chip itself has disabled the data path, and
         * stops us racing with our data end IRQ.
         */
        if (host->size == 0) {
                mmci_set_mask1(host, 0);
                writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
        }

        return IRQ_HANDLED;
}

static void mmci_write_sdio_irq_bit(struct mmci_host *host, int enable)
{
        void __iomem *base = host->base;
        u32 mask = readl_relaxed(base + MMCIMASK0);

        if (enable)
                writel_relaxed(mask | MCI_ST_SDIOITMASK, base + MMCIMASK0);
        else
                writel_relaxed(mask & ~MCI_ST_SDIOITMASK, base + MMCIMASK0);
}

static void mmci_signal_sdio_irq(struct mmci_host *host, u32 status)
{
        if (status & MCI_ST_SDIOIT) {
                mmci_write_sdio_irq_bit(host, 0);
                sdio_signal_irq(host->mmc);
        }
}

/*
 * Handle completion of command and data transfers.
 */
static irqreturn_t mmci_irq(int irq, void *dev_id)
{
        struct mmci_host *host = dev_id;
        u32 status;

        spin_lock(&host->lock);
        host->irq_action = IRQ_HANDLED;

        do {
                status = readl(host->base + MMCISTATUS);
                if (!status)
                        break;

                if (host->singleirq) {
                        if (status & host->mask1_reg)
                                mmci_pio_irq(irq, dev_id);

                        status &= ~host->variant->irq_pio_mask;
                }

                /*
                 * Busy detection is managed by mmci_cmd_irq(), including to
                 * clear the corresponding IRQ.
                 */
                status &= readl(host->base + MMCIMASK0);
                if (host->variant->busy_detect)
                        writel(status & ~host->variant->busy_detect_mask,
                               host->base + MMCICLEAR);
                else
                        writel(status, host->base + MMCICLEAR);

                dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);

                if (host->variant->reversed_irq_handling) {
                        mmci_data_irq(host, host->data, status);
                        mmci_cmd_irq(host, host->cmd, status);
                } else {
                        mmci_cmd_irq(host, host->cmd, status);
                        mmci_data_irq(host, host->data, status);
                }

                if (host->variant->supports_sdio_irq)
                        mmci_signal_sdio_irq(host, status);

                /*
                 * Busy detection has been handled by mmci_cmd_irq() above.
                 * Clear the status bit to prevent polling in IRQ context.
                 */
                if (host->variant->busy_detect_flag)
                        status &= ~host->variant->busy_detect_flag;

        } while (status);

        spin_unlock(&host->lock);

        return host->irq_action;
}

/*
 * mmci_irq_thread() - A threaded IRQ handler that manages a reset of the HW.
 *
 * A reset is needed for some variants, where a datatimeout for a R1B request
 * causes the DPSM to stay busy (non-functional).
 */
static irqreturn_t mmci_irq_thread(int irq, void *dev_id)
{
        struct mmci_host *host = dev_id;
        unsigned long flags;

        if (host->rst) {
                reset_control_assert(host->rst);
                udelay(2);
                reset_control_deassert(host->rst);
        }

        spin_lock_irqsave(&host->lock, flags);
        writel(host->clk_reg, host->base + MMCICLOCK);
        writel(host->pwr_reg, host->base + MMCIPOWER);
        writel(MCI_IRQENABLE | host->variant->start_err,
               host->base + MMCIMASK0);

        host->irq_action = IRQ_HANDLED;
        mmci_request_end(host, host->mrq);
        spin_unlock_irqrestore(&host->lock, flags);

        return host->irq_action;
}

static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
        struct mmci_host *host = mmc_priv(mmc);
        unsigned long flags;

        WARN_ON(host->mrq != NULL);

        mrq->cmd->error = mmci_validate_data(host, mrq->data);
        if (mrq->cmd->error) {
                mmc_request_done(mmc, mrq);
                return;
        }

        spin_lock_irqsave(&host->lock, flags);

        host->mrq = mrq;

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

        if (mrq->data &&
            (host->variant->datactrl_first || mrq->data->flags & MMC_DATA_READ))
                mmci_start_data(host, mrq->data);

        if (mrq->sbc)
                mmci_start_command(host, mrq->sbc, 0);
        else
                mmci_start_command(host, mrq->cmd, 0);

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

static void mmci_set_max_busy_timeout(struct mmc_host *mmc)
{
        struct mmci_host *host = mmc_priv(mmc);
        u32 max_busy_timeout = 0;

        if (!host->variant->busy_detect)
                return;

        if (host->variant->busy_timeout && mmc->actual_clock)
                max_busy_timeout = U32_MAX / DIV_ROUND_UP(mmc->actual_clock,
                                                          MSEC_PER_SEC);

        mmc->max_busy_timeout = max_busy_timeout;
}

static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct mmci_host *host = mmc_priv(mmc);
        struct variant_data *variant = host->variant;
        u32 pwr = 0;
        unsigned long flags;
        int ret;

        switch (ios->power_mode) {
        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;
        case MMC_POWER_UP:
                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);

                /*
                 * The ST Micro variant doesn't have the PL180s MCI_PWR_UP
                 * and instead uses MCI_PWR_ON so apply whatever value is
                 * configured in the variant data.
                 */
                pwr |= variant->pwrreg_powerup;

                break;
        case MMC_POWER_ON:
                if (!IS_ERR(mmc->supply.vqmmc) && !host->vqmmc_enabled) {
                        ret = regulator_enable(mmc->supply.vqmmc);
                        if (ret < 0)
                                dev_err(mmc_dev(mmc),
                                        "failed to enable vqmmc regulator\n");
                        else
                                host->vqmmc_enabled = true;
                }

                pwr |= MCI_PWR_ON;
                break;
        }

        if (variant->signal_direction && ios->power_mode != MMC_POWER_OFF) {
                /*
                 * The ST Micro variant has some additional bits
                 * indicating signal direction for the signals in
                 * the SD/MMC bus and feedback-clock usage.
                 */
                pwr |= host->pwr_reg_add;

                if (ios->bus_width == MMC_BUS_WIDTH_4)
                        pwr &= ~MCI_ST_DATA74DIREN;
                else if (ios->bus_width == MMC_BUS_WIDTH_1)
                        pwr &= (~MCI_ST_DATA74DIREN &
                                ~MCI_ST_DATA31DIREN &
                                ~MCI_ST_DATA2DIREN);
        }

        if (variant->opendrain) {
                if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
                        pwr |= variant->opendrain;
        } else {
                /*
                 * If the variant cannot configure the pads by its own, then we
                 * expect the pinctrl to be able to do that for us
                 */
                if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
                        pinctrl_select_state(host->pinctrl, host->pins_opendrain);
                else
                        pinctrl_select_default_state(mmc_dev(mmc));
        }

        /*
         * If clock = 0 and the variant requires the MMCIPOWER to be used for
         * gating the clock, the MCI_PWR_ON bit is cleared.
         */
        if (!ios->clock && variant->pwrreg_clkgate)
                pwr &= ~MCI_PWR_ON;

        if (host->variant->explicit_mclk_control &&
            ios->clock != host->clock_cache) {
                ret = clk_set_rate(host->clk, ios->clock);
                if (ret < 0)
                        dev_err(mmc_dev(host->mmc),
                                "Error setting clock rate (%d)\n", ret);
                else
                        host->mclk = clk_get_rate(host->clk);
        }
        host->clock_cache = ios->clock;

        spin_lock_irqsave(&host->lock, flags);

        if (host->ops && host->ops->set_clkreg)
                host->ops->set_clkreg(host, ios->clock);
        else
                mmci_set_clkreg(host, ios->clock);

        mmci_set_max_busy_timeout(mmc);

        if (host->ops && host->ops->set_pwrreg)
                host->ops->set_pwrreg(host, pwr);
        else
                mmci_write_pwrreg(host, pwr);

        mmci_reg_delay(host);

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

static int mmci_get_cd(struct mmc_host *mmc)
{
        struct mmci_host *host = mmc_priv(mmc);
        struct mmci_platform_data *plat = host->plat;
        unsigned int status = mmc_gpio_get_cd(mmc);

        if (status == -ENOSYS) {
                if (!plat->status)
                        return 1; /* Assume always present */

                status = plat->status(mmc_dev(host->mmc));
        }
        return status;
}

static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct mmci_host *host = mmc_priv(mmc);
        int ret;

        ret = mmc_regulator_set_vqmmc(mmc, ios);

        if (!ret && host->ops && host->ops->post_sig_volt_switch)
                ret = host->ops->post_sig_volt_switch(host, ios);
        else if (ret)
                ret = 0;

        if (ret < 0)
                dev_warn(mmc_dev(mmc), "Voltage switch failed\n");

        return ret;
}

static void mmci_enable_sdio_irq(struct mmc_host *mmc, int enable)
{
        struct mmci_host *host = mmc_priv(mmc);
        unsigned long flags;

        if (enable)
                /* Keep the SDIO mode bit if SDIO irqs are enabled */
                pm_runtime_get_sync(mmc_dev(mmc));

        spin_lock_irqsave(&host->lock, flags);
        mmci_write_sdio_irq_bit(host, enable);
        spin_unlock_irqrestore(&host->lock, flags);

        if (!enable) {
                pm_runtime_put_autosuspend(mmc_dev(mmc));
        }
}

static void mmci_ack_sdio_irq(struct mmc_host *mmc)
{
        struct mmci_host *host = mmc_priv(mmc);
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);
        mmci_write_sdio_irq_bit(host, 1);
        spin_unlock_irqrestore(&host->lock, flags);
}

static struct mmc_host_ops mmci_ops = {
        .request        = mmci_request,
        .pre_req        = mmci_pre_request,
        .post_req       = mmci_post_request,
        .set_ios        = mmci_set_ios,
        .get_ro         = mmc_gpio_get_ro,
        .get_cd         = mmci_get_cd,
        .start_signal_voltage_switch = mmci_sig_volt_switch,
};

static void mmci_probe_level_translator(struct mmc_host *mmc)
{
        struct device *dev = mmc_dev(mmc);
        struct mmci_host *host = mmc_priv(mmc);
        struct gpio_desc *cmd_gpio;
        struct gpio_desc *ck_gpio;
        struct gpio_desc *ckin_gpio;
        int clk_hi, clk_lo;

        /*
         * Assume the level translator is present if st,use-ckin is set.
         * This is to cater for DTs which do not implement this test.
         */
        host->clk_reg_add |= MCI_STM32_CLK_SELCKIN;

        cmd_gpio = gpiod_get(dev, "st,cmd", GPIOD_OUT_HIGH);
        if (IS_ERR(cmd_gpio))
                goto exit_cmd;

        ck_gpio = gpiod_get(dev, "st,ck", GPIOD_OUT_HIGH);
        if (IS_ERR(ck_gpio))
                goto exit_ck;

        ckin_gpio = gpiod_get(dev, "st,ckin", GPIOD_IN);
        if (IS_ERR(ckin_gpio))
                goto exit_ckin;

        /* All GPIOs are valid, test whether level translator works */

        /* Sample CKIN */
        clk_hi = !!gpiod_get_value(ckin_gpio);

        /* Set CK low */
        gpiod_set_value(ck_gpio, 0);

        /* Sample CKIN */
        clk_lo = !!gpiod_get_value(ckin_gpio);

        /* Tristate all */
        gpiod_direction_input(cmd_gpio);
        gpiod_direction_input(ck_gpio);

        /* Level translator is present if CK signal is propagated to CKIN */
        if (!clk_hi || clk_lo) {
                host->clk_reg_add &= ~MCI_STM32_CLK_SELCKIN;
                dev_warn(dev,
                         "Level translator inoperable, CK signal not detected on CKIN, disabling.\n");
        }

        gpiod_put(ckin_gpio);

exit_ckin:
        gpiod_put(ck_gpio);
exit_ck:
        gpiod_put(cmd_gpio);
exit_cmd:
        pinctrl_select_default_state(dev);
}

static int mmci_of_parse(struct device_node *np, struct mmc_host *mmc)
{
        struct mmci_host *host = mmc_priv(mmc);
        int ret = mmc_of_parse(mmc);

        if (ret)
                return ret;

        if (of_property_read_bool(np, "st,sig-dir-dat0"))
                host->pwr_reg_add |= MCI_ST_DATA0DIREN;
        if (of_property_read_bool(np, "st,sig-dir-dat2"))
                host->pwr_reg_add |= MCI_ST_DATA2DIREN;
        if (of_property_read_bool(np, "st,sig-dir-dat31"))
                host->pwr_reg_add |= MCI_ST_DATA31DIREN;
        if (of_property_read_bool(np, "st,sig-dir-dat74"))
                host->pwr_reg_add |= MCI_ST_DATA74DIREN;
        if (of_property_read_bool(np, "st,sig-dir-cmd"))
                host->pwr_reg_add |= MCI_ST_CMDDIREN;
        if (of_property_read_bool(np, "st,sig-pin-fbclk"))
                host->pwr_reg_add |= MCI_ST_FBCLKEN;
        if (of_property_read_bool(np, "st,sig-dir"))
                host->pwr_reg_add |= MCI_STM32_DIRPOL;
        if (of_property_read_bool(np, "st,neg-edge"))
                host->clk_reg_add |= MCI_STM32_CLK_NEGEDGE;
        if (of_property_read_bool(np, "st,use-ckin"))
                mmci_probe_level_translator(mmc);

        if (of_property_read_bool(np, "mmc-cap-mmc-highspeed"))
                mmc->caps |= MMC_CAP_MMC_HIGHSPEED;
        if (of_property_read_bool(np, "mmc-cap-sd-highspeed"))
                mmc->caps |= MMC_CAP_SD_HIGHSPEED;

        return 0;
}

static int mmci_probe(struct amba_device *dev,
        const struct amba_id *id)
{
        struct mmci_platform_data *plat = dev->dev.platform_data;
        struct device_node *np = dev->dev.of_node;
        struct variant_data *variant = id->data;
        struct mmci_host *host;
        struct mmc_host *mmc;
        int ret;

        /* Must have platform data or Device Tree. */
        if (!plat && !np) {
                dev_err(&dev->dev, "No plat data or DT found\n");
                return -EINVAL;
        }

        if (!plat) {
                plat = devm_kzalloc(&dev->dev, sizeof(*plat), GFP_KERNEL);
                if (!plat)
                        return -ENOMEM;
        }

        mmc = devm_mmc_alloc_host(&dev->dev, sizeof(*host));
        if (!mmc)
                return -ENOMEM;

        host = mmc_priv(mmc);
        host->mmc = mmc;
        host->mmc_ops = &mmci_ops;
        mmc->ops = &mmci_ops;

        ret = mmci_of_parse(np, mmc);
        if (ret)
                return ret;

        /*
         * Some variant (STM32) doesn't have opendrain bit, nevertheless
         * pins can be set accordingly using pinctrl
         */
        if (!variant->opendrain) {
                host->pinctrl = devm_pinctrl_get(&dev->dev);
                if (IS_ERR(host->pinctrl))
                        return dev_err_probe(&dev->dev, PTR_ERR(host->pinctrl),
                                             "failed to get pinctrl\n");

                host->pins_opendrain = pinctrl_lookup_state(host->pinctrl,
                                                            MMCI_PINCTRL_STATE_OPENDRAIN);
                if (IS_ERR(host->pins_opendrain))
                        return dev_err_probe(&dev->dev, PTR_ERR(host->pins_opendrain),
                                             "Can't select opendrain pins\n");
        }

        host->hw_designer = amba_manf(dev);
        host->hw_revision = amba_rev(dev);
        dev_dbg(mmc_dev(mmc), "designer ID = 0x%02x\n", host->hw_designer);
        dev_dbg(mmc_dev(mmc), "revision = 0x%01x\n", host->hw_revision);

        host->clk = devm_clk_get(&dev->dev, NULL);
        if (IS_ERR(host->clk))
                return PTR_ERR(host->clk);

        ret = clk_prepare_enable(host->clk);
        if (ret)
                return ret;

        if (variant->qcom_fifo)
                host->get_rx_fifocnt = mmci_qcom_get_rx_fifocnt;
        else
                host->get_rx_fifocnt = mmci_get_rx_fifocnt;

        host->plat = plat;
        host->variant = variant;
        host->mclk = clk_get_rate(host->clk);
        /*
         * According to the spec, mclk is max 100 MHz,
         * so we try to adjust the clock down to this,
         * (if possible).
         */
        if (host->mclk > variant->f_max) {
                ret = clk_set_rate(host->clk, variant->f_max);
                if (ret < 0)
                        goto clk_disable;
                host->mclk = clk_get_rate(host->clk);
                dev_dbg(mmc_dev(mmc), "eventual mclk rate: %u Hz\n",
                        host->mclk);
        }

        host->phybase = dev->res.start;
        host->base = devm_ioremap_resource(&dev->dev, &dev->res);
        if (IS_ERR(host->base)) {
                ret = PTR_ERR(host->base);
                goto clk_disable;
        }

        if (variant->init)
                variant->init(host);

        /*
         * The ARM and ST versions of the block have slightly different
         * clock divider equations which means that the minimum divider
         * differs too.
         * on Qualcomm like controllers get the nearest minimum clock to 100Khz
         */
        if (variant->st_clkdiv)
                mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
        else if (variant->stm32_clkdiv)
                mmc->f_min = DIV_ROUND_UP(host->mclk, 2046);
        else if (variant->explicit_mclk_control)
                mmc->f_min = clk_round_rate(host->clk, 100000);
        else
                mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
        /*
         * If no maximum operating frequency is supplied, fall back to use
         * the module parameter, which has a (low) default value in case it
         * is not specified. Either value must not exceed the clock rate into
         * the block, of course.
         */
        if (mmc->f_max)
                mmc->f_max = variant->explicit_mclk_control ?
                                min(variant->f_max, mmc->f_max) :
                                min(host->mclk, mmc->f_max);
        else
                mmc->f_max = variant->explicit_mclk_control ?
                                fmax : min(host->mclk, fmax);


        dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max);

        host->rst = devm_reset_control_get_optional_exclusive(&dev->dev, NULL);
        if (IS_ERR(host->rst)) {
                ret = PTR_ERR(host->rst);
                goto clk_disable;
        }
        ret = reset_control_deassert(host->rst);
        if (ret)
                dev_err(mmc_dev(mmc), "failed to de-assert reset\n");

        /* Get regulators and the supported OCR mask */
        ret = mmc_regulator_get_supply(mmc);
        if (ret)
                goto clk_disable;

        if (!mmc->ocr_avail)
                mmc->ocr_avail = plat->ocr_mask;
        else if (plat->ocr_mask)
                dev_warn(mmc_dev(mmc), "Platform OCR mask is ignored\n");

        /* We support these capabilities. */
        mmc->caps |= MMC_CAP_CMD23;

        /*
         * Enable busy detection.
         */
        if (variant->busy_detect) {
                mmci_ops.card_busy = mmci_card_busy;
                /*
                 * Not all variants have a flag to enable busy detection
                 * in the DPSM, but if they do, set it here.
                 */
                if (variant->busy_dpsm_flag)
                        mmci_write_datactrlreg(host,
                                               host->variant->busy_dpsm_flag);
                mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
        }

        if (variant->supports_sdio_irq && host->mmc->caps & MMC_CAP_SDIO_IRQ) {
                mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;

                mmci_ops.enable_sdio_irq = mmci_enable_sdio_irq;
                mmci_ops.ack_sdio_irq   = mmci_ack_sdio_irq;

                mmci_write_datactrlreg(host,
                                       host->variant->datactrl_mask_sdio);
        }

        /* Variants with mandatory busy timeout in HW needs R1B responses. */
        if (variant->busy_timeout)
                mmc->caps |= MMC_CAP_NEED_RSP_BUSY;

        /* Prepare a CMD12 - needed to clear the DPSM on some variants. */
        host->stop_abort.opcode = MMC_STOP_TRANSMISSION;
        host->stop_abort.arg = 0;
        host->stop_abort.flags = MMC_RSP_R1B | MMC_CMD_AC;

        /* We support these PM capabilities. */
        mmc->pm_caps |= MMC_PM_KEEP_POWER;

        /*
         * We can do SGIO
         */
        mmc->max_segs = NR_SG;

        /*
         * Since only a certain number of bits are valid in the data length
         * register, we must ensure that we don't exceed 2^num-1 bytes in a
         * single request.
         */
        mmc->max_req_size = (1 << variant->datalength_bits) - 1;

        /*
         * Set the maximum segment size.  Since we aren't doing DMA
         * (yet) we are only limited by the data length register.
         */
        mmc->max_seg_size = mmc->max_req_size;

        /*
         * Block size can be up to 2048 bytes, but must be a power of two.
         */
        mmc->max_blk_size = 1 << variant->datactrl_blocksz;

        /*
         * Limit the number of blocks transferred so that we don't overflow
         * the maximum request size.
         */
        mmc->max_blk_count = mmc->max_req_size >> variant->datactrl_blocksz;

        spin_lock_init(&host->lock);

        writel(0, host->base + MMCIMASK0);

        if (variant->mmcimask1)
                writel(0, host->base + MMCIMASK1);

        writel(0xfff, host->base + MMCICLEAR);

        /*
         * If:
         * - not using DT but using a descriptor table, or
         * - using a table of descriptors ALONGSIDE DT, or
         * look up these descriptors named "cd" and "wp" right here, fail
         * silently of these do not exist
         */
        if (!np) {
                ret = mmc_gpiod_request_cd(mmc, "cd", 0, false, 0);
                if (ret == -EPROBE_DEFER)
                        goto clk_disable;

                ret = mmc_gpiod_request_ro(mmc, "wp", 0, 0);
                if (ret == -EPROBE_DEFER)
                        goto clk_disable;
        }

        ret = devm_request_threaded_irq(&dev->dev, dev->irq[0], mmci_irq,
                                        mmci_irq_thread, IRQF_SHARED,
                                        DRIVER_NAME " (cmd)", host);
        if (ret)
                goto clk_disable;

        if (!dev->irq[1])
                host->singleirq = true;
        else {
                ret = devm_request_irq(&dev->dev, dev->irq[1], mmci_pio_irq,
                                IRQF_SHARED, DRIVER_NAME " (pio)", host);
                if (ret)
                        goto clk_disable;
        }

        if (host->variant->busy_detect)
                INIT_DELAYED_WORK(&host->ux500_busy_timeout_work,
                                  ux500_busy_timeout_work);

        writel(MCI_IRQENABLE | variant->start_err, host->base + MMCIMASK0);

        amba_set_drvdata(dev, mmc);

        dev_info(&dev->dev, "%s: PL%03x manf %x rev%u at 0x%08llx irq %d,%d (pio)\n",
                 mmc_hostname(mmc), amba_part(dev), amba_manf(dev),
                 amba_rev(dev), (unsigned long long)dev->res.start,
                 dev->irq[0], dev->irq[1]);

        mmci_dma_setup(host);

        pm_runtime_set_autosuspend_delay(&dev->dev, 50);
        pm_runtime_use_autosuspend(&dev->dev);

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

        pm_runtime_put(&dev->dev);
        return 0;

 clk_disable:
        clk_disable_unprepare(host->clk);
        return ret;
}

static void mmci_remove(struct amba_device *dev)
{
        struct mmc_host *mmc = amba_get_drvdata(dev);

        if (mmc) {
                struct mmci_host *host = mmc_priv(mmc);
                struct variant_data *variant = host->variant;

                /*
                 * Undo pm_runtime_put() in probe.  We use the _sync
                 * version here so that we can access the primecell.
                 */
                pm_runtime_get_sync(&dev->dev);

                mmc_remove_host(mmc);

                writel(0, host->base + MMCIMASK0);

                if (variant->mmcimask1)
                        writel(0, host->base + MMCIMASK1);

                writel(0, host->base + MMCICOMMAND);
                writel(0, host->base + MMCIDATACTRL);

                mmci_dma_release(host);
                clk_disable_unprepare(host->clk);
        }
}

static void mmci_save(struct mmci_host *host)
{
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);

        writel(0, host->base + MMCIMASK0);
        if (host->variant->pwrreg_nopower) {
                writel(0, host->base + MMCIDATACTRL);
                writel(0, host->base + MMCIPOWER);
                writel(0, host->base + MMCICLOCK);
        }
        mmci_reg_delay(host);

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

static void mmci_restore(struct mmci_host *host)
{
        unsigned long flags;

        spin_lock_irqsave(&host->lock, flags);

        if (host->variant->pwrreg_nopower) {
                writel(host->clk_reg, host->base + MMCICLOCK);
                writel(host->datactrl_reg, host->base + MMCIDATACTRL);
                writel(host->pwr_reg, host->base + MMCIPOWER);
        }
        writel(MCI_IRQENABLE | host->variant->start_err,
               host->base + MMCIMASK0);
        mmci_reg_delay(host);

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

static int mmci_runtime_suspend(struct device *dev)
{
        struct amba_device *adev = to_amba_device(dev);
        struct mmc_host *mmc = amba_get_drvdata(adev);

        if (mmc) {
                struct mmci_host *host = mmc_priv(mmc);
                pinctrl_pm_select_sleep_state(dev);
                mmci_save(host);
                clk_disable_unprepare(host->clk);
        }

        return 0;
}

static int mmci_runtime_resume(struct device *dev)
{
        struct amba_device *adev = to_amba_device(dev);
        struct mmc_host *mmc = amba_get_drvdata(adev);

        if (mmc) {
                struct mmci_host *host = mmc_priv(mmc);
                clk_prepare_enable(host->clk);
                mmci_restore(host);
                pinctrl_select_default_state(dev);
        }

        return 0;
}

static const struct dev_pm_ops mmci_dev_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
        RUNTIME_PM_OPS(mmci_runtime_suspend, mmci_runtime_resume, NULL)
};

static const struct amba_id mmci_ids[] = {
        {
                .id     = 0x00041180,
                .mask   = 0xff0fffff,
                .data   = &variant_arm,
        },
        {
                .id     = 0x01041180,
                .mask   = 0xff0fffff,
                .data   = &variant_arm_extended_fifo,
        },
        {
                .id     = 0x02041180,
                .mask   = 0xff0fffff,
                .data   = &variant_arm_extended_fifo_hwfc,
        },
        {
                .id     = 0x00041181,
                .mask   = 0x000fffff,
                .data   = &variant_arm,
        },
        /* ST Micro variants */
        {
                .id     = 0x00180180,
                .mask   = 0x00ffffff,
                .data   = &variant_u300,
        },
        {
                .id     = 0x10180180,
                .mask   = 0xf0ffffff,
                .data   = &variant_nomadik,
        },
        {
                .id     = 0x00280180,
                .mask   = 0x00ffffff,
                .data   = &variant_nomadik,
        },
        {
                .id     = 0x00480180,
                .mask   = 0xf0ffffff,
                .data   = &variant_ux500,
        },
        {
                .id     = 0x10480180,
                .mask   = 0xf0ffffff,
                .data   = &variant_ux500v2,
        },
        {
                .id     = 0x00880180,
                .mask   = 0x00ffffff,
                .data   = &variant_stm32,
        },
        {
                .id     = 0x10153180,
                .mask   = 0xf0ffffff,
                .data   = &variant_stm32_sdmmc,
        },
        {
                .id     = 0x00253180,
                .mask   = 0xf0ffffff,
                .data   = &variant_stm32_sdmmcv2,
        },
        {
                .id     = 0x20253180,
                .mask   = 0xf0ffffff,
                .data   = &variant_stm32_sdmmcv2,
        },
        {
                .id     = 0x00353180,
                .mask   = 0xf0ffffff,
                .data   = &variant_stm32_sdmmcv3,
        },
        /* Qualcomm variants */
        {
                .id     = 0x00051180,
                .mask   = 0x000fffff,
                .data   = &variant_qcom,
        },
        { 0, 0 },
};

MODULE_DEVICE_TABLE(amba, mmci_ids);

static struct amba_driver mmci_driver = {
        .drv            = {
                .name   = DRIVER_NAME,
                .pm     = pm_ptr(&mmci_dev_pm_ops),
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe          = mmci_probe,
        .remove         = mmci_remove,
        .id_table       = mmci_ids,
};

module_amba_driver(mmci_driver);

module_param(fmax, uint, 0444);

MODULE_DESCRIPTION("ARM PrimeCell PL180/181 Multimedia Card Interface driver");
MODULE_LICENSE("GPL");