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

#include "core.h"
#include "bus.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;

        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;

        ret = sdio_read_fbr(func);
        if (ret)
                goto fail;

        ret = sdio_read_func_cis(func);
        if (ret)
                goto fail;

        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)
{
        int ret;
        int cccr_vsn;
        unsigned char data;

        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_1_20) {
                printk(KERN_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, &data);
                if (ret)
                        goto out;

                if (data & SDIO_SPEED_SHS)
                        card->cccr.high_speed = 1;
        }

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;

        mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);

        return 0;
}

/*
 * 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 (!card->cccr.disable_cd)
                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);
}

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

        speed |= SDIO_SPEED_EHS;

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

        mmc_card_set_highspeed(card);
        mmc_set_timing(card->host, MMC_TIMING_SD_HS);

        return 0;
}

/*
 * 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)
{
        struct mmc_card *card;
        int err;

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

        /*
         * Inform the card of the voltage
         */
        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;
        }

        card->type = MMC_TYPE_SDIO;

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

                mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
        }

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

        /*
         * Read the common registers.
         */
        err = sdio_read_cccr(card);
        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) {
                        err = -ENOENT;
                        goto err;
                }
                card = oldcard;
                return 0;
        }

        /*
         * Switch to high-speed (if supported).
         */
        err = sdio_enable_hs(card);
        if (err)
                goto remove;

        /*
         * Change to the card's maximum speed.
         */
        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.
                 */
                mmc_set_clock(host, 50000000);
        } else {
                mmc_set_clock(host, card->cis.max_dtr);
        }

        /*
         * Switch to wider bus (if supported).
         */
        err = sdio_enable_wide(card);
        if (err)
                goto remove;

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

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

        mmc_claim_host(host);

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

        mmc_release_host(host);

        if (err) {
                mmc_sdio_remove(host);

                mmc_claim_host(host);
                mmc_detach_bus(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);
                }
        }

        return err;
}

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

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

        /* Basic card reinitialization. */
        mmc_claim_host(host);
        err = mmc_sdio_init_card(host, host->ocr, host->card);
        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 const struct mmc_bus_ops mmc_sdio_ops = {
        .remove = mmc_sdio_remove,
        .detect = mmc_sdio_detect,
        .suspend = mmc_sdio_suspend,
        .resume = mmc_sdio_resume,
};


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

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

        mmc_attach_bus(host, &mmc_sdio_ops);

        /*
         * Sanity check the voltages that the card claims to
         * support.
         */
        if (ocr & 0x7F) {
                printk(KERN_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);
        if (err)
                goto err;
        card = host->card;

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

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

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

        mmc_release_host(host);

        /*
         * First add the card to the driver model...
         */
        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;
        }

        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. */
        if (host->card)
                mmc_sdio_remove(host);
err:
        mmc_detach_bus(host);
        mmc_release_host(host);

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

        return err;
}