/*
 *  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
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#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/pm.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/gpio.h>
#include <linux/of_gpio.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 <asm/div64.h>
#include <asm/io.h>

#include "mmci.h"
#include "mmci_qcom_dml.h"

#define DRIVER_NAME "mmci-pl18x"

static unsigned int fmax = 515633;

/**
 * struct variant_data - MMCI variant-specific quirks
 * @clkreg: default value for MCICLOCK register
 * @clkreg_enable: enable value for MMCICLOCK register
 * @clkreg_8bit_bus_enable: enable value for 8 bit bus
 * @clkreg_neg_edge_enable: enable value for inverted data/cmd output
 * @datalength_bits: number of bits in the MMCIDATALENGTH register
 * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
 *            is asserted (likewise for RX)
 * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
 *                is asserted (likewise for RX)
 * @data_cmd_enable: enable value for data commands.
 * @st_sdio: enable ST specific SDIO logic
 * @st_clkdiv: true if using a ST-specific clock divider algorithm
 * @datactrl_mask_ddrmode: ddr mode mask in datactrl register.
 * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
 * @blksz_datactrl4: true if Block size is at b4..b16 position in datactrl
 *                   register
 * @datactrl_mask_sdio: SDIO enable mask in datactrl register
 * @pwrreg_powerup: power up value for MMCIPOWER register
 * @f_max: maximum clk frequency supported by the controller.
 * @signal_direction: input/out direction of bus signals can be indicated
 * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
 * @busy_detect: true if the variant supports busy detection on DAT0.
 * @busy_dpsm_flag: bitmask enabling busy detection in the DPSM
 * @busy_detect_flag: bitmask identifying the bit in the MMCISTATUS register
 *                    indicating that the card is busy
 * @busy_detect_mask: bitmask identifying the bit in the MMCIMASK0 to mask for
 *                    getting busy end detection interrupts
 * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
 * @explicit_mclk_control: enable explicit mclk control in driver.
 * @qcom_fifo: enables qcom specific fifo pio read logic.
 * @qcom_dml: enables qcom specific dma glue for dma transfers.
 * @reversed_irq_handling: handle data irq before cmd irq.
 */
struct variant_data {
        unsigned int            clkreg;
        unsigned int            clkreg_enable;
        unsigned int            clkreg_8bit_bus_enable;
        unsigned int            clkreg_neg_edge_enable;
        unsigned int            datalength_bits;
        unsigned int            fifosize;
        unsigned int            fifohalfsize;
        unsigned int            data_cmd_enable;
        unsigned int            datactrl_mask_ddrmode;
        unsigned int            datactrl_mask_sdio;
        bool                    st_sdio;
        bool                    st_clkdiv;
        bool                    blksz_datactrl16;
        bool                    blksz_datactrl4;
        u32                     pwrreg_powerup;
        u32                     f_max;
        bool                    signal_direction;
        bool                    pwrreg_clkgate;
        bool                    busy_detect;
        u32                     busy_dpsm_flag;
        u32                     busy_detect_flag;
        u32                     busy_detect_mask;
        bool                    pwrreg_nopower;
        bool                    explicit_mclk_control;
        bool                    qcom_fifo;
        bool                    qcom_dml;
        bool                    reversed_irq_handling;
};

static struct variant_data variant_arm = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .datalength_bits        = 16,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
        .reversed_irq_handling  = true,
};

static struct variant_data variant_arm_extended_fifo = {
        .fifosize               = 128 * 4,
        .fifohalfsize           = 64 * 4,
        .datalength_bits        = 16,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
};

static struct variant_data variant_arm_extended_fifo_hwfc = {
        .fifosize               = 128 * 4,
        .fifohalfsize           = 64 * 4,
        .clkreg_enable          = MCI_ARM_HWFCEN,
        .datalength_bits        = 16,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 100000000,
};

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,
        .datalength_bits        = 16,
        .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,
};

static struct variant_data variant_nomadik = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
        .clkreg                 = MCI_CLK_ENABLE,
        .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
        .datalength_bits        = 24,
        .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,
};

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,
        .datalength_bits        = 24,
        .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,
};

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,
        .datactrl_mask_ddrmode  = MCI_DPSM_ST_DDRMODE,
        .datalength_bits        = 24,
        .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
        .st_sdio                = true,
        .st_clkdiv              = true,
        .blksz_datactrl16       = 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,
};

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,
        .data_cmd_enable        = MCI_CPSM_QCOM_DATCMD,
        .blksz_datactrl4        = true,
        .datalength_bits        = 24,
        .pwrreg_powerup         = MCI_PWR_UP,
        .f_max                  = 208000000,
        .explicit_mclk_control  = true,
        .qcom_fifo              = true,
        .qcom_dml               = true,
};

/* 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;
}

/*
 * Validate mmc prerequisites
 */
static int mmci_validate_data(struct mmci_host *host,
                              struct mmc_data *data)
{
        if (!data)
                return 0;

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

        return 0;
}

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
 */
static 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
 */
static 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 if enabled */
        datactrl |= host->datactrl_reg & host->variant->busy_dpsm_flag;

        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_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;

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

                mask0 &= ~MCI_IRQ1MASK;
                mask0 |= mask;

                writel(mask0, base + MMCIMASK0);
        }

        writel(mask, base + MMCIMASK1);
}

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);
}

/*
 * 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
static void mmci_dma_setup(struct mmci_host *host)
{
        const char *rxname, *txname;
        struct variant_data *variant = host->variant;

        host->dma_rx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "rx");
        host->dma_tx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "tx");

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

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

        if (host->dma_rx_channel)
                rxname = dma_chan_name(host->dma_rx_channel);
        else
                rxname = "none";

        if (host->dma_tx_channel)
                txname = dma_chan_name(host->dma_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 (host->dma_tx_channel) {
                struct device *dev = host->dma_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 (host->dma_rx_channel) {
                struct device *dev = host->dma_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 (variant->qcom_dml && host->dma_rx_channel && host->dma_tx_channel)
                if (dml_hw_init(host, host->mmc->parent->of_node))
                        variant->qcom_dml = false;
}

/*
 * This is used in or so inline it
 * so it can be discarded.
 */
static inline void mmci_dma_release(struct mmci_host *host)
{
        if (host->dma_rx_channel)
                dma_release_channel(host->dma_rx_channel);
        if (host->dma_tx_channel)
                dma_release_channel(host->dma_tx_channel);
        host->dma_rx_channel = host->dma_tx_channel = NULL;
}

static void mmci_dma_data_error(struct mmci_host *host)
{
        dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
        dmaengine_terminate_all(host->dma_current);
        host->dma_in_progress = false;
        host->dma_current = NULL;
        host->dma_desc_current = NULL;
        host->data->host_cookie = 0;
}

static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
{
        struct dma_chan *chan;

        if (data->flags & MMC_DATA_READ)
                chan = host->dma_rx_channel;
        else
                chan = host->dma_tx_channel;

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

static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
{
        u32 status;
        int i;

        /* 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_data_error(host);
                if (!data->error)
                        data->error = -EIO;
        }

        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;
        host->dma_current = NULL;
        host->dma_desc_current = NULL;
}

/* prepares DMA channel and DMA descriptor, returns non-zero on failure */
static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
                                struct dma_chan **dma_chan,
                                struct dma_async_tx_descriptor **dma_desc)
{
        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 = false,
        };
        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 = host->dma_rx_channel;
        } else {
                conf.direction = DMA_MEM_TO_DEV;
                chan = host->dma_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;

        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;
}

static inline int mmci_dma_prep_data(struct mmci_host *host,
                                     struct mmc_data *data)
{
        /* Check if next job is already prepared. */
        if (host->dma_current && host->dma_desc_current)
                return 0;

        /* No job were prepared thus do it now. */
        return __mmci_dma_prep_data(host, data, &host->dma_current,
                                    &host->dma_desc_current);
}

static inline int mmci_dma_prep_next(struct mmci_host *host,
                                     struct mmc_data *data)
{
        struct mmci_host_next *nd = &host->next_data;
        return __mmci_dma_prep_data(host, data, &nd->dma_chan, &nd->dma_desc);
}

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

        ret = mmci_dma_prep_data(host, host->data);
        if (ret)
                return ret;

        /* 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);
        host->dma_in_progress = true;
        dmaengine_submit(host->dma_desc_current);
        dma_async_issue_pending(host->dma_current);

        if (host->variant->qcom_dml)
                dml_start_xfer(host, data);

        datactrl |= MCI_DPSM_DMAENABLE;

        /* 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_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
        struct mmci_host_next *next = &host->next_data;

        WARN_ON(data->host_cookie && data->host_cookie != next->cookie);
        WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan));

        host->dma_desc_current = next->dma_desc;
        host->dma_current = next->dma_chan;
        next->dma_desc = NULL;
        next->dma_chan = NULL;
}

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;
        struct mmci_host_next *nd = &host->next_data;

        if (!data)
                return;

        BUG_ON(data->host_cookie);

        if (mmci_validate_data(host, data))
                return;

        if (!mmci_dma_prep_next(host, data))
                data->host_cookie = ++nd->cookie < 0 ? 1 : nd->cookie;
}

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_dma_unmap(host, data);

        if (err) {
                struct mmci_host_next *next = &host->next_data;
                struct dma_chan *chan;
                if (data->flags & MMC_DATA_READ)
                        chan = host->dma_rx_channel;
                else
                        chan = host->dma_tx_channel;
                dmaengine_terminate_all(chan);

                if (host->dma_desc_current == next->dma_desc)
                        host->dma_desc_current = NULL;

                if (host->dma_current == next->dma_chan) {
                        host->dma_in_progress = false;
                        host->dma_current = NULL;
                }

                next->dma_desc = NULL;
                next->dma_chan = NULL;
                data->host_cookie = 0;
        }
}

#else
/* Blank functions if the DMA engine is not available */
static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
{
}
static inline void mmci_dma_setup(struct mmci_host *host)
{
}

static inline void mmci_dma_release(struct mmci_host *host)
{
}

static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
{
}

static inline void mmci_dma_finalize(struct mmci_host *host,
                                     struct mmc_data *data)
{
}

static inline void mmci_dma_data_error(struct mmci_host *host)
{
}

static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
{
        return -ENOSYS;
}

#define mmci_pre_request NULL
#define mmci_post_request NULL

#endif

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;
        int blksz_bits;

        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);

        blksz_bits = ffs(data->blksz) - 1;
        BUG_ON(1 << blksz_bits != data->blksz);

        if (variant->blksz_datactrl16)
                datactrl = MCI_DPSM_ENABLE | (data->blksz << 16);
        else if (variant->blksz_datactrl4)
                datactrl = MCI_DPSM_ENABLE | (data->blksz << 4);
        else
                datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;

        if (data->flags & MMC_DATA_READ)
                datactrl |= MCI_DPSM_DIRECTION;

        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_data(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;

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

        if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
                writel(0, base + MMCICOMMAND);
                mmci_reg_delay(host);
        }

        c |= cmd->opcode | MCI_CPSM_ENABLE;
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136)
                        c |= MCI_CPSM_LONGRSP;
                c |= MCI_CPSM_RESPONSE;
        }
        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_data_irq(struct mmci_host *host, struct mmc_data *data,
              unsigned int status)
{
        /* Make sure we have data to handle */
        if (!data)
                return;

        /* First check for errors */
        if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_STARTBITERR|
                      MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
                u32 remain, success;

                /* Terminate the DMA transfer */
                if (dma_inprogress(host)) {
                        mmci_dma_data_error(host);
                        mmci_dma_unmap(host, data);
                }

                /*
                 * 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.
                 */
                remain = readl(host->base + MMCIDATACNT);
                success = data->blksz * data->blocks - remain;

                dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
                        status, success);
                if (status & MCI_DATACRCFAIL) {
                        /* Last block was not successful */
                        success -= 1;
                        data->error = -EILSEQ;
                } else if (status & MCI_DATATIMEOUT) {
                        data->error = -ETIMEDOUT;
                } else if (status & MCI_STARTBITERR) {
                        data->error = -ECOMM;
                } else if (status & MCI_TXUNDERRUN) {
                        data->error = -EIO;
                } else if (status & 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) {
                if (dma_inprogress(host))
                        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 || host->mrq->sbc) {
                        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)
{
        void __iomem *base = host->base;
        bool sbc;

        if (!cmd)
                return;

        sbc = (cmd == host->mrq->sbc);

        /*
         * 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 (!((status|host->busy_status) &
              (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND)))
                return;

        /*
         * ST Micro variant: handle busy detection.
         */
        if (host->variant->busy_detect) {
                bool busy_resp = !!(cmd->flags & MMC_RSP_BUSY);

                /* We are busy with a command, return */
                if (host->busy_status &&
                    (status & host->variant->busy_detect_flag))
                        return;

                /*
                 * We were not busy, but we now got a busy response on
                 * something that was not an error, and we double-check
                 * that the special busy status bit is still set before
                 * proceeding.
                 */
                if (!host->busy_status && busy_resp &&
                    !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) &&
                    (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) {

                        /* Clear the busy start IRQ */
                        writel(host->variant->busy_detect_mask,
                               host->base + MMCICLEAR);

                        /* Unmask the busy end IRQ */
                        writel(readl(base + MMCIMASK0) |
                               host->variant->busy_detect_mask,
                               base + MMCIMASK0);
                        /*
                         * Now cache the last response status code (until
                         * the busy bit goes low), and return.
                         */
                        host->busy_status =
                                status & (MCI_CMDSENT|MCI_CMDRESPEND);
                        return;
                }

                /*
                 * At this point we are not busy with a command, we have
                 * not received a new busy request, clear and mask the busy
                 * end IRQ and fall through to process the IRQ.
                 */
                if (host->busy_status) {

                        writel(host->variant->busy_detect_mask,
                               host->base + MMCICLEAR);

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

        host->cmd = NULL;

        if (status & MCI_CMDTIMEOUT) {
                cmd->error = -ETIMEDOUT;
        } else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
                cmd->error = -EILSEQ;
        } 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 */
                        if (dma_inprogress(host)) {
                                mmci_dma_data_error(host);
                                mmci_dma_unmap(host, host->data);
                        }
                        mmci_stop_data(host);
                }
                mmci_request_end(host, host->mrq);
        } else if (sbc) {
                mmci_start_command(host, host->mrq->cmd, 0);
        } else if (!(cmd->data->flags & MMC_DATA_READ)) {
                mmci_start_data(host, cmd->data);
        }
}

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;
        unsigned long flags;
        u32 status;

        status = readl(base + MMCISTATUS);

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

        local_irq_save(flags);

        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);

        local_irq_restore(flags);

        /*
         * 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;
}

/*
 * 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;
        int ret = 0;

        spin_lock(&host->lock);

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

                if (host->singleirq) {
                        if (status & readl(host->base + MMCIMASK1))
                                mmci_pio_irq(irq, dev_id);

                        status &= ~MCI_IRQ1MASK;
                }

                /*
                 * We intentionally clear the MCI_ST_CARDBUSY IRQ (if it's
                 * enabled) in mmci_cmd_irq() function where ST Micro busy
                 * detection variant is handled. Considering the HW seems to be
                 * triggering the IRQ on both edges while monitoring DAT0 for
                 * busy completion and that same status bit is used to monitor
                 * start and end of busy detection, special care must be taken
                 * to make sure that both start and end interrupts are always
                 * cleared one after the other.
                 */
                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);
                }

                /*
                 * Don't poll for busy completion in irq context.
                 */
                if (host->variant->busy_detect && host->busy_status)
                        status &= ~host->variant->busy_detect_flag;

                ret = 1;
        } while (status);

        spin_unlock(&host->lock);

        return IRQ_RETVAL(ret);
}

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 && 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_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;

        if (host->plat->ios_handler &&
                host->plat->ios_handler(mmc_dev(mmc), ios))
                        dev_err(mmc_dev(mmc), "platform ios_handler failed\n");

        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 (ios->bus_mode == MMC_BUSMODE_OPENDRAIN) {
                if (host->hw_designer != AMBA_VENDOR_ST)
                        pwr |= MCI_ROD;
                else {
                        /*
                         * The ST Micro variant use the ROD bit for something
                         * else and only has OD (Open Drain).
                         */
                        pwr |= MCI_OD;
                }
        }

        /*
         * 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);

        mmci_set_clkreg(host, ios->clock);
        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)
{
        int ret = 0;

        if (!IS_ERR(mmc->supply.vqmmc)) {

                switch (ios->signal_voltage) {
                case MMC_SIGNAL_VOLTAGE_330:
                        ret = regulator_set_voltage(mmc->supply.vqmmc,
                                                2700000, 3600000);
                        break;
                case MMC_SIGNAL_VOLTAGE_180:
                        ret = regulator_set_voltage(mmc->supply.vqmmc,
                                                1700000, 1950000);
                        break;
                case MMC_SIGNAL_VOLTAGE_120:
                        ret = regulator_set_voltage(mmc->supply.vqmmc,
                                                1100000, 1300000);
                        break;
                }

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

        return ret;
}

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 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_get_property(np, "st,sig-dir-dat0", NULL))
                host->pwr_reg_add |= MCI_ST_DATA0DIREN;
        if (of_get_property(np, "st,sig-dir-dat2", NULL))
                host->pwr_reg_add |= MCI_ST_DATA2DIREN;
        if (of_get_property(np, "st,sig-dir-dat31", NULL))
                host->pwr_reg_add |= MCI_ST_DATA31DIREN;
        if (of_get_property(np, "st,sig-dir-dat74", NULL))
                host->pwr_reg_add |= MCI_ST_DATA74DIREN;
        if (of_get_property(np, "st,sig-dir-cmd", NULL))
                host->pwr_reg_add |= MCI_ST_CMDDIREN;
        if (of_get_property(np, "st,sig-pin-fbclk", NULL))
                host->pwr_reg_add |= MCI_ST_FBCLKEN;

        if (of_get_property(np, "mmc-cap-mmc-highspeed", NULL))
                mmc->caps |= MMC_CAP_MMC_HIGHSPEED;
        if (of_get_property(np, "mmc-cap-sd-highspeed", NULL))
                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 = mmc_alloc_host(sizeof(struct mmci_host), &dev->dev);
        if (!mmc)
                return -ENOMEM;

        ret = mmci_of_parse(np, mmc);
        if (ret)
                goto host_free;

        host = mmc_priv(mmc);
        host->mmc = mmc;

        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)) {
                ret = PTR_ERR(host->clk);
                goto host_free;
        }

        ret = clk_prepare_enable(host->clk);
        if (ret)
                goto host_free;

        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;
        }

        /*
         * 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->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);

        /* Get regulators and the supported OCR mask */
        ret = mmc_regulator_get_supply(mmc);
        if (ret == -EPROBE_DEFER)
                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");

        /* DT takes precedence over platform data. */
        if (!np) {
                if (!plat->cd_invert)
                        mmc->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
                mmc->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
        }

        /* 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;
                mmc->max_busy_timeout = 0;
        }

        mmc->ops = &mmci_ops;

        /* 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 << 11;

        /*
         * Limit the number of blocks transferred so that we don't overflow
         * the maximum request size.
         */
        mmc->max_blk_count = mmc->max_req_size >> 11;

        spin_lock_init(&host->lock);

        writel(0, host->base + MMCIMASK0);
        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 and proceed to try platform data
         */
        if (!np) {
                ret = mmc_gpiod_request_cd(mmc, "cd", 0, false, 0, NULL);
                if (ret < 0) {
                        if (ret == -EPROBE_DEFER)
                                goto clk_disable;
                        else if (gpio_is_valid(plat->gpio_cd)) {
                                ret = mmc_gpio_request_cd(mmc, plat->gpio_cd, 0);
                                if (ret)
                                        goto clk_disable;
                        }
                }

                ret = mmc_gpiod_request_ro(mmc, "wp", 0, false, 0, NULL);
                if (ret < 0) {
                        if (ret == -EPROBE_DEFER)
                                goto clk_disable;
                        else if (gpio_is_valid(plat->gpio_wp)) {
                                ret = mmc_gpio_request_ro(mmc, plat->gpio_wp);
                                if (ret)
                                        goto clk_disable;
                        }
                }
        }

        ret = devm_request_irq(&dev->dev, dev->irq[0], mmci_irq, 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;
        }

        writel(MCI_IRQENABLE, 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);

        mmc_add_host(mmc);

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

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

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

        if (mmc) {
                struct mmci_host *host = mmc_priv(mmc);

                /*
                 * 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);
                writel(0, host->base + MMCIMASK1);

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

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

        return 0;
}

#ifdef CONFIG_PM
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->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_pm_select_default_state(dev);
        }

        return 0;
}
#endif

static const struct dev_pm_ops mmci_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
                                pm_runtime_force_resume)
        SET_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,
        },
        /* 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     = &mmci_dev_pm_ops,
        },
        .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");