/*
 *  linux/drivers/mmc/sdio.c
 *
 *  Copyright 2006-2007 Pierre Ossman
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/err.h>
#include <linux/pm_runtime.h>

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/sdio_ids.h>

#include "core.h"
#include "bus.h"
#include "sd.h"
#include "sdio_bus.h"
#include "mmc_ops.h"
#include "sd_ops.h"
#include "sdio_ops.h"
#include "sdio_cis.h"

static int sdio_read_fbr(struct sdio_func *func)
{
        int ret;
        unsigned char data;

        if (mmc_card_nonstd_func_interface(func->card)) {
                func->class = SDIO_CLASS_NONE;
                return 0;
        }

        ret = mmc_io_rw_direct(func->card, 0, 0,
                SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
        if (ret)
                goto out;

        data &= 0x0f;

        if (data == 0x0f) {
                ret = mmc_io_rw_direct(func->card, 0, 0,
                        SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF_EXT, 0, &data);
                if (ret)
                        goto out;
        }

        func->class = data;

out:
        return ret;
}

static int sdio_init_func(struct mmc_card *card, unsigned int fn)
{
        int ret;
        struct sdio_func *func;

        BUG_ON(fn > SDIO_MAX_FUNCS);

        func = sdio_alloc_func(card);
        if (IS_ERR(func))
                return PTR_ERR(func);

        func->num = fn;

        if (!(card->quirks & MMC_QUIRK_NONSTD_SDIO)) {
                ret = sdio_read_fbr(func);
                if (ret)
                        goto fail;

                ret = sdio_read_func_cis(func);
                if (ret)
                        goto fail;
        } else {
                func->vendor = func->card->cis.vendor;
                func->device = func->card->cis.device;
                func->max_blksize = func->card->cis.blksize;
        }

        card->sdio_func[fn - 1] = func;

        return 0;

fail:
        /*
         * It is okay to remove the function here even though we hold
         * the host lock as we haven't registered the device yet.
         */
        sdio_remove_func(func);
        return ret;
}

static int sdio_read_cccr(struct mmc_card *card, u32 ocr)
{
        int ret;
        int cccr_vsn;
        int uhs = ocr & R4_18V_PRESENT;
        unsigned char data;
        unsigned char speed;

        memset(&card->cccr, 0, sizeof(struct sdio_cccr));

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR, 0, &data);
        if (ret)
                goto out;

        cccr_vsn = data & 0x0f;

        if (cccr_vsn > SDIO_CCCR_REV_3_00) {
                pr_err("%s: unrecognised CCCR structure version %d\n",
                        mmc_hostname(card->host), cccr_vsn);
                return -EINVAL;
        }

        card->cccr.sdio_vsn = (data & 0xf0) >> 4;

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CAPS, 0, &data);
        if (ret)
                goto out;

        if (data & SDIO_CCCR_CAP_SMB)
                card->cccr.multi_block = 1;
        if (data & SDIO_CCCR_CAP_LSC)
                card->cccr.low_speed = 1;
        if (data & SDIO_CCCR_CAP_4BLS)
                card->cccr.wide_bus = 1;

        if (cccr_vsn >= SDIO_CCCR_REV_1_10) {
                ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_POWER, 0, &data);
                if (ret)
                        goto out;

                if (data & SDIO_POWER_SMPC)
                        card->cccr.high_power = 1;
        }

        if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
                ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
                if (ret)
                        goto out;

                card->scr.sda_spec3 = 0;
                card->sw_caps.sd3_bus_mode = 0;
                card->sw_caps.sd3_drv_type = 0;
                if (cccr_vsn >= SDIO_CCCR_REV_3_00 && uhs) {
                        card->scr.sda_spec3 = 1;
                        ret = mmc_io_rw_direct(card, 0, 0,
                                SDIO_CCCR_UHS, 0, &data);
                        if (ret)
                                goto out;

                        if (card->host->caps &
                                (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
                                 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
                                 MMC_CAP_UHS_DDR50)) {
                                if (data & SDIO_UHS_DDR50)
                                        card->sw_caps.sd3_bus_mode
                                                |= SD_MODE_UHS_DDR50;

                                if (data & SDIO_UHS_SDR50)
                                        card->sw_caps.sd3_bus_mode
                                                |= SD_MODE_UHS_SDR50;

                                if (data & SDIO_UHS_SDR104)
                                        card->sw_caps.sd3_bus_mode
                                                |= SD_MODE_UHS_SDR104;
                        }

                        ret = mmc_io_rw_direct(card, 0, 0,
                                SDIO_CCCR_DRIVE_STRENGTH, 0, &data);
                        if (ret)
                                goto out;

                        if (data & SDIO_DRIVE_SDTA)
                                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_A;
                        if (data & SDIO_DRIVE_SDTC)
                                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_C;
                        if (data & SDIO_DRIVE_SDTD)
                                card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_D;
                }

                /* if no uhs mode ensure we check for high speed */
                if (!card->sw_caps.sd3_bus_mode) {
                        if (speed & SDIO_SPEED_SHS) {
                                card->cccr.high_speed = 1;
                                card->sw_caps.hs_max_dtr = 50000000;
                        } else {
                                card->cccr.high_speed = 0;
                                card->sw_caps.hs_max_dtr = 25000000;
                        }
                }
        }

out:
        return ret;
}

static int sdio_enable_wide(struct mmc_card *card)
{
        int ret;
        u8 ctrl;

        if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
                return 0;

        if (card->cccr.low_speed && !card->cccr.wide_bus)
                return 0;

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
        if (ret)
                return ret;

        ctrl |= SDIO_BUS_WIDTH_4BIT;

        ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
        if (ret)
                return ret;

        return 1;
}

/*
 * If desired, disconnect the pull-up resistor on CD/DAT[3] (pin 1)
 * of the card. This may be required on certain setups of boards,
 * controllers and embedded sdio device which do not need the card's
 * pull-up. As a result, card detection is disabled and power is saved.
 */
static int sdio_disable_cd(struct mmc_card *card)
{
        int ret;
        u8 ctrl;

        if (!mmc_card_disable_cd(card))
                return 0;

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
        if (ret)
                return ret;

        ctrl |= SDIO_BUS_CD_DISABLE;

        return mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
}

/*
 * Devices that remain active during a system suspend are
 * put back into 1-bit mode.
 */
static int sdio_disable_wide(struct mmc_card *card)
{
        int ret;
        u8 ctrl;

        if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
                return 0;

        if (card->cccr.low_speed && !card->cccr.wide_bus)
                return 0;

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
        if (ret)
                return ret;

        if (!(ctrl & SDIO_BUS_WIDTH_4BIT))
                return 0;

        ctrl &= ~SDIO_BUS_WIDTH_4BIT;
        ctrl |= SDIO_BUS_ASYNC_INT;

        ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
        if (ret)
                return ret;

        mmc_set_bus_width(card->host, MMC_BUS_WIDTH_1);

        return 0;
}


static int sdio_enable_4bit_bus(struct mmc_card *card)
{
        int err;

        if (card->type == MMC_TYPE_SDIO)
                return sdio_enable_wide(card);

        if ((card->host->caps & MMC_CAP_4_BIT_DATA) &&
                (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
                err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
                if (err)
                        return err;
        } else
                return 0;

        err = sdio_enable_wide(card);
        if (err <= 0)
                mmc_app_set_bus_width(card, MMC_BUS_WIDTH_1);

        return err;
}


/*
 * Test if the card supports high-speed mode and, if so, switch to it.
 */
static int mmc_sdio_switch_hs(struct mmc_card *card, int enable)
{
        int ret;
        u8 speed;

        if (!(card->host->caps & MMC_CAP_SD_HIGHSPEED))
                return 0;

        if (!card->cccr.high_speed)
                return 0;

        ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
        if (ret)
                return ret;

        if (enable)
                speed |= SDIO_SPEED_EHS;
        else
                speed &= ~SDIO_SPEED_EHS;

        ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
        if (ret)
                return ret;

        return 1;
}

/*
 * Enable SDIO/combo card's high-speed mode. Return 0/1 if [not]supported.
 */
static int sdio_enable_hs(struct mmc_card *card)
{
        int ret;

        ret = mmc_sdio_switch_hs(card, true);
        if (ret <= 0 || card->type == MMC_TYPE_SDIO)
                return ret;

        ret = mmc_sd_switch_hs(card);
        if (ret <= 0)
                mmc_sdio_switch_hs(card, false);

        return ret;
}

static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
{
        unsigned max_dtr;

        if (mmc_card_highspeed(card)) {
                /*
                 * The SDIO specification doesn't mention how
                 * the CIS transfer speed register relates to
                 * high-speed, but it seems that 50 MHz is
                 * mandatory.
                 */
                max_dtr = 50000000;
        } else {
                max_dtr = card->cis.max_dtr;
        }

        if (card->type == MMC_TYPE_SD_COMBO)
                max_dtr = min(max_dtr, mmc_sd_get_max_clock(card));

        return max_dtr;
}

static unsigned char host_drive_to_sdio_drive(int host_strength)
{
        switch (host_strength) {
        case MMC_SET_DRIVER_TYPE_A:
                return SDIO_DTSx_SET_TYPE_A;
        case MMC_SET_DRIVER_TYPE_B:
                return SDIO_DTSx_SET_TYPE_B;
        case MMC_SET_DRIVER_TYPE_C:
                return SDIO_DTSx_SET_TYPE_C;
        case MMC_SET_DRIVER_TYPE_D:
                return SDIO_DTSx_SET_TYPE_D;
        default:
                return SDIO_DTSx_SET_TYPE_B;
        }
}

static void sdio_select_driver_type(struct mmc_card *card)
{
        int host_drv_type = SD_DRIVER_TYPE_B;
        int card_drv_type = SD_DRIVER_TYPE_B;
        int drive_strength;
        unsigned char card_strength;
        int err;

        /*
         * If the host doesn't support any of the Driver Types A,C or D,
         * or there is no board specific handler then default Driver
         * Type B is used.
         */
        if (!(card->host->caps &
                (MMC_CAP_DRIVER_TYPE_A |
                 MMC_CAP_DRIVER_TYPE_C |
                 MMC_CAP_DRIVER_TYPE_D)))
                return;

        if (!card->host->ops->select_drive_strength)
                return;

        if (card->host->caps & MMC_CAP_DRIVER_TYPE_A)
                host_drv_type |= SD_DRIVER_TYPE_A;

        if (card->host->caps & MMC_CAP_DRIVER_TYPE_C)
                host_drv_type |= SD_DRIVER_TYPE_C;

        if (card->host->caps & MMC_CAP_DRIVER_TYPE_D)
                host_drv_type |= SD_DRIVER_TYPE_D;

        if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_A)
                card_drv_type |= SD_DRIVER_TYPE_A;

        if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_C)
                card_drv_type |= SD_DRIVER_TYPE_C;

        if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_D)
                card_drv_type |= SD_DRIVER_TYPE_D;

        /*
         * The drive strength that the hardware can support
         * depends on the board design.  Pass the appropriate
         * information and let the hardware specific code
         * return what is possible given the options
         */
        drive_strength = card->host->ops->select_drive_strength(
                card->sw_caps.uhs_max_dtr,
                host_drv_type, card_drv_type);

        /* if error just use default for drive strength B */
        err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_DRIVE_STRENGTH, 0,
                &card_strength);
        if (err)
                return;

        card_strength &= ~(SDIO_DRIVE_DTSx_MASK<<SDIO_DRIVE_DTSx_SHIFT);
        card_strength |= host_drive_to_sdio_drive(drive_strength);

        err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_DRIVE_STRENGTH,
                card_strength, NULL);

        /* if error default to drive strength B */
        if (!err)
                mmc_set_driver_type(card->host, drive_strength);
}


static int sdio_set_bus_speed_mode(struct mmc_card *card)
{
        unsigned int bus_speed, timing;
        int err;
        unsigned char speed;

        /*
         * If the host doesn't support any of the UHS-I modes, fallback on
         * default speed.
         */
        if (!(card->host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
            MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)))
                return 0;

        bus_speed = SDIO_SPEED_SDR12;
        timing = MMC_TIMING_UHS_SDR12;
        if ((card->host->caps & MMC_CAP_UHS_SDR104) &&
            (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR104)) {
                        bus_speed = SDIO_SPEED_SDR104;
                        timing = MMC_TIMING_UHS_SDR104;
                        card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
        } else if ((card->host->caps & MMC_CAP_UHS_DDR50) &&
                   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_DDR50)) {
                        bus_speed = SDIO_SPEED_DDR50;
                        timing = MMC_TIMING_UHS_DDR50;
                        card->sw_caps.uhs_max_dtr = UHS_DDR50_MAX_DTR;
        } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
                    MMC_CAP_UHS_SDR50)) && (card->sw_caps.sd3_bus_mode &
                    SD_MODE_UHS_SDR50)) {
                        bus_speed = SDIO_SPEED_SDR50;
                        timing = MMC_TIMING_UHS_SDR50;
                        card->sw_caps.uhs_max_dtr = UHS_SDR50_MAX_DTR;
        } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
                    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25)) &&
                   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR25)) {
                        bus_speed = SDIO_SPEED_SDR25;
                        timing = MMC_TIMING_UHS_SDR25;
                        card->sw_caps.uhs_max_dtr = UHS_SDR25_MAX_DTR;
        } else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
                    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25 |
                    MMC_CAP_UHS_SDR12)) && (card->sw_caps.sd3_bus_mode &
                    SD_MODE_UHS_SDR12)) {
                        bus_speed = SDIO_SPEED_SDR12;
                        timing = MMC_TIMING_UHS_SDR12;
                        card->sw_caps.uhs_max_dtr = UHS_SDR12_MAX_DTR;
        }

        err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
        if (err)
                return err;

        speed &= ~SDIO_SPEED_BSS_MASK;
        speed |= bus_speed;
        err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
        if (err)
                return err;

        if (bus_speed) {
                mmc_set_timing(card->host, timing);
                mmc_set_clock(card->host, card->sw_caps.uhs_max_dtr);
        }

        return 0;
}

/*
 * UHS-I specific initialization procedure
 */
static int mmc_sdio_init_uhs_card(struct mmc_card *card)
{
        int err;

        if (!card->scr.sda_spec3)
                return 0;

        /*
         * Switch to wider bus (if supported).
         */
        if (card->host->caps & MMC_CAP_4_BIT_DATA) {
                err = sdio_enable_4bit_bus(card);
                if (err > 0) {
                        mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
                        err = 0;
                }
        }

        /* Set the driver strength for the card */
        sdio_select_driver_type(card);

        /* Set bus speed mode of the card */
        err = sdio_set_bus_speed_mode(card);
        if (err)
                goto out;

        /* Initialize and start re-tuning timer */
        if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning)
                err = card->host->ops->execute_tuning(card->host,
                                                      MMC_SEND_TUNING_BLOCK);

out:

        return err;
}

/*
 * Handle the detection and initialisation of a card.
 *
 * In the case of a resume, "oldcard" will contain the card
 * we're trying to reinitialise.
 */
static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
                              struct mmc_card *oldcard, int powered_resume)
{
        struct mmc_card *card;
        int err;

        BUG_ON(!host);
        WARN_ON(!host->claimed);

        /*
         * Inform the card of the voltage
         */
        if (!powered_resume) {
                /* The initialization should be done at 3.3 V I/O voltage. */
                mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);

                err = mmc_send_io_op_cond(host, host->ocr, &ocr);
                if (err)
                        goto err;
        }

        /*
         * For SPI, enable CRC as appropriate.
         */
        if (mmc_host_is_spi(host)) {
                err = mmc_spi_set_crc(host, use_spi_crc);
                if (err)
                        goto err;
        }

        /*
         * Allocate card structure.
         */
        card = mmc_alloc_card(host, NULL);
        if (IS_ERR(card)) {
                err = PTR_ERR(card);
                goto err;
        }

        if ((ocr & R4_MEMORY_PRESENT) &&
            mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid, NULL) == 0) {
                card->type = MMC_TYPE_SD_COMBO;

                if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO ||
                    memcmp(card->raw_cid, oldcard->raw_cid, sizeof(card->raw_cid)) != 0)) {
                        mmc_remove_card(card);
                        return -ENOENT;
                }
        } else {
                card->type = MMC_TYPE_SDIO;

                if (oldcard && oldcard->type != MMC_TYPE_SDIO) {
                        mmc_remove_card(card);
                        return -ENOENT;
                }
        }

        /*
         * Call the optional HC's init_card function to handle quirks.
         */
        if (host->ops->init_card)
                host->ops->init_card(host, card);

        /*
         * If the host and card support UHS-I mode request the card
         * to switch to 1.8V signaling level.  No 1.8v signalling if
         * UHS mode is not enabled to maintain compatibilty and some
         * systems that claim 1.8v signalling in fact do not support
         * it.
         */
        if ((ocr & R4_18V_PRESENT) &&
                (host->caps &
                        (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
                         MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
                         MMC_CAP_UHS_DDR50))) {
                err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
                                true);
                if (err) {
                        ocr &= ~R4_18V_PRESENT;
                        host->ocr &= ~R4_18V_PRESENT;
                }
                err = 0;
        } else {
                ocr &= ~R4_18V_PRESENT;
                host->ocr &= ~R4_18V_PRESENT;
        }

        /*
         * For native busses:  set card RCA and quit open drain mode.
         */
        if (!powered_resume && !mmc_host_is_spi(host)) {
                err = mmc_send_relative_addr(host, &card->rca);
                if (err)
                        goto remove;

                /*
                 * Update oldcard with the new RCA received from the SDIO
                 * device -- we're doing this so that it's updated in the
                 * "card" struct when oldcard overwrites that later.
                 */
                if (oldcard)
                        oldcard->rca = card->rca;
        }

        /*
         * Read CSD, before selecting the card
         */
        if (!oldcard && card->type == MMC_TYPE_SD_COMBO) {
                err = mmc_sd_get_csd(host, card);
                if (err)
                        return err;

                mmc_decode_cid(card);
        }

        /*
         * Select card, as all following commands rely on that.
         */
        if (!powered_resume && !mmc_host_is_spi(host)) {
                err = mmc_select_card(card);
                if (err)
                        goto remove;
        }

        if (card->quirks & MMC_QUIRK_NONSTD_SDIO) {
                /*
                 * This is non-standard SDIO device, meaning it doesn't
                 * have any CIA (Common I/O area) registers present.
                 * It's host's responsibility to fill cccr and cis
                 * structures in init_card().
                 */
                mmc_set_clock(host, card->cis.max_dtr);

                if (card->cccr.high_speed) {
                        mmc_card_set_highspeed(card);
                        mmc_set_timing(card->host, MMC_TIMING_SD_HS);
                }

                goto finish;
        }

        /*
         * Read the common registers.
         */
        err = sdio_read_cccr(card, ocr);
        if (err)
                goto remove;

        /*
         * Read the common CIS tuples.
         */
        err = sdio_read_common_cis(card);
        if (err)
                goto remove;

        if (oldcard) {
                int same = (card->cis.vendor == oldcard->cis.vendor &&
                            card->cis.device == oldcard->cis.device);
                mmc_remove_card(card);
                if (!same)
                        return -ENOENT;

                card = oldcard;
        }
        mmc_fixup_device(card, NULL);

        if (card->type == MMC_TYPE_SD_COMBO) {
                err = mmc_sd_setup_card(host, card, oldcard != NULL);
                /* handle as SDIO-only card if memory init failed */
                if (err) {
                        mmc_go_idle(host);
                        if (mmc_host_is_spi(host))
                                /* should not fail, as it worked previously */
                                mmc_spi_set_crc(host, use_spi_crc);
                        card->type = MMC_TYPE_SDIO;
                } else
                        card->dev.type = &sd_type;
        }

        /*
         * If needed, disconnect card detection pull-up resistor.
         */
        err = sdio_disable_cd(card);
        if (err)
                goto remove;

        /* Initialization sequence for UHS-I cards */
        /* Only if card supports 1.8v and UHS signaling */
        if ((ocr & R4_18V_PRESENT) && card->sw_caps.sd3_bus_mode) {
                err = mmc_sdio_init_uhs_card(card);
                if (err)
                        goto remove;

                /* Card is an ultra-high-speed card */
                mmc_card_set_uhs(card);
        } else {
                /*
                 * Switch to high-speed (if supported).
                 */
                err = sdio_enable_hs(card);
                if (err > 0)
                        mmc_sd_go_highspeed(card);
                else if (err)
                        goto remove;

                /*
                 * Change to the card's maximum speed.
                 */
                mmc_set_clock(host, mmc_sdio_get_max_clock(card));

                /*
                 * Switch to wider bus (if supported).
                 */
                err = sdio_enable_4bit_bus(card);
                if (err > 0)
                        mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
                else if (err)
                        goto remove;
        }
finish:
        if (!oldcard)
                host->card = card;
        return 0;

remove:
        if (!oldcard)
                mmc_remove_card(card);

err:
        return err;
}

/*
 * Host is being removed. Free up the current card.
 */
static void mmc_sdio_remove(struct mmc_host *host)
{
        int i;

        BUG_ON(!host);
        BUG_ON(!host->card);

        for (i = 0;i < host->card->sdio_funcs;i++) {
                if (host->card->sdio_func[i]) {
                        sdio_remove_func(host->card->sdio_func[i]);
                        host->card->sdio_func[i] = NULL;
                }
        }

        mmc_remove_card(host->card);
        host->card = NULL;
}

/*
 * Card detection - card is alive.
 */
static int mmc_sdio_alive(struct mmc_host *host)
{
        return mmc_select_card(host->card);
}

/*
 * Card detection callback from host.
 */
static void mmc_sdio_detect(struct mmc_host *host)
{
        int err;

        BUG_ON(!host);
        BUG_ON(!host->card);

        /* Make sure card is powered before detecting it */
        if (host->caps & MMC_CAP_POWER_OFF_CARD) {
                err = pm_runtime_get_sync(&host->card->dev);
                if (err < 0)
                        goto out;
        }

        mmc_claim_host(host);

        /*
         * Just check if our card has been removed.
         */
        err = _mmc_detect_card_removed(host);

        mmc_release_host(host);

        /*
         * Tell PM core it's OK to power off the card now.
         *
         * The _sync variant is used in order to ensure that the card
         * is left powered off in case an error occurred, and the card
         * is going to be removed.
         *
         * Since there is no specific reason to believe a new user
         * is about to show up at this point, the _sync variant is
         * desirable anyway.
         */
        if (host->caps & MMC_CAP_POWER_OFF_CARD)
                pm_runtime_put_sync(&host->card->dev);

out:
        if (err) {
                mmc_sdio_remove(host);

                mmc_claim_host(host);
                mmc_detach_bus(host);
                mmc_power_off(host);
                mmc_release_host(host);
        }
}

/*
 * SDIO suspend.  We need to suspend all functions separately.
 * Therefore all registered functions must have drivers with suspend
 * and resume methods.  Failing that we simply remove the whole card.
 */
static int mmc_sdio_suspend(struct mmc_host *host)
{
        int i, err = 0;

        for (i = 0; i < host->card->sdio_funcs; i++) {
                struct sdio_func *func = host->card->sdio_func[i];
                if (func && sdio_func_present(func) && func->dev.driver) {
                        const struct dev_pm_ops *pmops = func->dev.driver->pm;
                        if (!pmops || !pmops->suspend || !pmops->resume) {
                                /* force removal of entire card in that case */
                                err = -ENOSYS;
                        } else
                                err = pmops->suspend(&func->dev);
                        if (err)
                                break;
                }
        }
        while (err && --i >= 0) {
                struct sdio_func *func = host->card->sdio_func[i];
                if (func && sdio_func_present(func) && func->dev.driver) {
                        const struct dev_pm_ops *pmops = func->dev.driver->pm;
                        pmops->resume(&func->dev);
                }
        }

        if (!err && mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
                mmc_claim_host(host);
                sdio_disable_wide(host->card);
                mmc_release_host(host);
        }

        return err;
}

static int mmc_sdio_resume(struct mmc_host *host)
{
        int i, err = 0;

        BUG_ON(!host);
        BUG_ON(!host->card);

        /* Basic card reinitialization. */
        mmc_claim_host(host);

        /* No need to reinitialize powered-resumed nonremovable cards */
        if (mmc_card_is_removable(host) || !mmc_card_keep_power(host))
                err = mmc_sdio_init_card(host, host->ocr, host->card,
                                        mmc_card_keep_power(host));
        else if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
                /* We may have switched to 1-bit mode during suspend */
                err = sdio_enable_4bit_bus(host->card);
                if (err > 0) {
                        mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
                        err = 0;
                }
        }

        if (!err && host->sdio_irqs)
                mmc_signal_sdio_irq(host);
        mmc_release_host(host);

        /*
         * If the card looked to be the same as before suspending, then
         * we proceed to resume all card functions.  If one of them returns
         * an error then we simply return that error to the core and the
         * card will be redetected as new.  It is the responsibility of
         * the function driver to perform further tests with the extra
         * knowledge it has of the card to confirm the card is indeed the
         * same as before suspending (same MAC address for network cards,
         * etc.) and return an error otherwise.
         */
        for (i = 0; !err && i < host->card->sdio_funcs; i++) {
                struct sdio_func *func = host->card->sdio_func[i];
                if (func && sdio_func_present(func) && func->dev.driver) {
                        const struct dev_pm_ops *pmops = func->dev.driver->pm;
                        err = pmops->resume(&func->dev);
                }
        }

        return err;
}

static int mmc_sdio_power_restore(struct mmc_host *host)
{
        int ret;
        u32 ocr;

        BUG_ON(!host);
        BUG_ON(!host->card);

        mmc_claim_host(host);

        /*
         * Reset the card by performing the same steps that are taken by
         * mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.
         *
         * sdio_reset() is technically not needed. Having just powered up the
         * hardware, it should already be in reset state. However, some
         * platforms (such as SD8686 on OLPC) do not instantly cut power,
         * meaning that a reset is required when restoring power soon after
         * powering off. It is harmless in other cases.
         *
         * The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,
         * is not necessary for non-removable cards. However, it is required
         * for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and
         * harmless in other situations.
         *
         * With these steps taken, mmc_select_voltage() is also required to
         * restore the correct voltage setting of the card.

         */

        /* The initialization should be done at 3.3 V I/O voltage. */
        if (!mmc_card_keep_power(host))
                mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330, 0);

        sdio_reset(host);
        mmc_go_idle(host);
        mmc_send_if_cond(host, host->ocr_avail);

        ret = mmc_send_io_op_cond(host, 0, &ocr);
        if (ret)
                goto out;

        if (host->ocr_avail_sdio)
                host->ocr_avail = host->ocr_avail_sdio;

        host->ocr = mmc_select_voltage(host, ocr & ~0x7F);
        if (!host->ocr) {
                ret = -EINVAL;
                goto out;
        }

        ret = mmc_sdio_init_card(host, host->ocr, host->card,
                                mmc_card_keep_power(host));
        if (!ret && host->sdio_irqs)
                mmc_signal_sdio_irq(host);

out:
        mmc_release_host(host);

        return ret;
}

static const struct mmc_bus_ops mmc_sdio_ops = {
        .remove = mmc_sdio_remove,
        .detect = mmc_sdio_detect,
        .suspend = mmc_sdio_suspend,
        .resume = mmc_sdio_resume,
        .power_restore = mmc_sdio_power_restore,
        .alive = mmc_sdio_alive,
};


/*
 * Starting point for SDIO card init.
 */
int mmc_attach_sdio(struct mmc_host *host)
{
        int err, i, funcs;
        u32 ocr;
        struct mmc_card *card;

        BUG_ON(!host);
        WARN_ON(!host->claimed);

        err = mmc_send_io_op_cond(host, 0, &ocr);
        if (err)
                return err;

        mmc_attach_bus(host, &mmc_sdio_ops);
        if (host->ocr_avail_sdio)
                host->ocr_avail = host->ocr_avail_sdio;

        /*
         * Sanity check the voltages that the card claims to
         * support.
         */
        if (ocr & 0x7F) {
                pr_warning("%s: card claims to support voltages "
                       "below the defined range. These will be ignored.\n",
                       mmc_hostname(host));
                ocr &= ~0x7F;
        }

        host->ocr = mmc_select_voltage(host, ocr);

        /*
         * Can we support the voltage(s) of the card(s)?
         */
        if (!host->ocr) {
                err = -EINVAL;
                goto err;
        }

        /*
         * Detect and init the card.
         */
        err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
        if (err) {
                if (err == -EAGAIN) {
                        /*
                         * Retry initialization with S18R set to 0.
                         */
                        host->ocr &= ~R4_18V_PRESENT;
                        err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
                }
                if (err)
                        goto err;
        }
        card = host->card;

        /*
         * Enable runtime PM only if supported by host+card+board
         */
        if (host->caps & MMC_CAP_POWER_OFF_CARD) {
                /*
                 * Let runtime PM core know our card is active
                 */
                err = pm_runtime_set_active(&card->dev);
                if (err)
                        goto remove;

                /*
                 * Enable runtime PM for this card
                 */
                pm_runtime_enable(&card->dev);
        }

        /*
         * The number of functions on the card is encoded inside
         * the ocr.
         */
        funcs = (ocr & 0x70000000) >> 28;
        card->sdio_funcs = 0;

        /*
         * Initialize (but don't add) all present functions.
         */
        for (i = 0; i < funcs; i++, card->sdio_funcs++) {
                err = sdio_init_func(host->card, i + 1);
                if (err)
                        goto remove;

                /*
                 * Enable Runtime PM for this func (if supported)
                 */
                if (host->caps & MMC_CAP_POWER_OFF_CARD)
                        pm_runtime_enable(&card->sdio_func[i]->dev);
        }

        /*
         * First add the card to the driver model...
         */
        mmc_release_host(host);
        err = mmc_add_card(host->card);
        if (err)
                goto remove_added;

        /*
         * ...then the SDIO functions.
         */
        for (i = 0;i < funcs;i++) {
                err = sdio_add_func(host->card->sdio_func[i]);
                if (err)
                        goto remove_added;
        }

        mmc_claim_host(host);
        return 0;


remove_added:
        /* Remove without lock if the device has been added. */
        mmc_sdio_remove(host);
        mmc_claim_host(host);
remove:
        /* And with lock if it hasn't been added. */
        mmc_release_host(host);
        if (host->card)
                mmc_sdio_remove(host);
        mmc_claim_host(host);
err:
        mmc_detach_bus(host);

        pr_err("%s: error %d whilst initialising SDIO card\n",
                mmc_hostname(host), err);

        return err;
}