mmc: Test bus-width for old MMC devices

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / mmc / core / mmc.c

/*
 *  linux/drivers/mmc/core/mmc.c
 *
 *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
 *  Copyright (C) 2005-2007 Pierre Ossman, All Rights Reserved.
 *  MMCv4 support Copyright (C) 2006 Philip Langdale, All Rights Reserved.
 *
 * 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/err.h>
#include <linux/slab.h>

#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>

#include "core.h"
#include "bus.h"
#include "mmc_ops.h"

static const unsigned int tran_exp[] = {
        10000,          100000,         1000000,        10000000,
        0,              0,              0,              0
};

static const unsigned char tran_mant[] = {
        0,      10,     12,     13,     15,     20,     25,     30,
        35,     40,     45,     50,     55,     60,     70,     80,
};

static const unsigned int tacc_exp[] = {
        1,      10,     100,    1000,   10000,  100000, 1000000, 10000000,
};

static const unsigned int tacc_mant[] = {
        0,      10,     12,     13,     15,     20,     25,     30,
        35,     40,     45,     50,     55,     60,     70,     80,
};

#define UNSTUFF_BITS(resp,start,size)                                   \
        ({                                                              \
                const int __size = size;                                \
                const u32 __mask = (__size < 32 ? 1 << __size : 0) - 1; \
                const int __off = 3 - ((start) / 32);                   \
                const int __shft = (start) & 31;                        \
                u32 __res;                                              \
                                                                        \
                __res = resp[__off] >> __shft;                          \
                if (__size + __shft > 32)                               \
                        __res |= resp[__off-1] << ((32 - __shft) % 32); \
                __res & __mask;                                         \
        })

/*
 * Given the decoded CSD structure, decode the raw CID to our CID structure.
 */
static int mmc_decode_cid(struct mmc_card *card)
{
        u32 *resp = card->raw_cid;

        /*
         * The selection of the format here is based upon published
         * specs from sandisk and from what people have reported.
         */
        switch (card->csd.mmca_vsn) {
        case 0: /* MMC v1.0 - v1.2 */
        case 1: /* MMC v1.4 */
                card->cid.manfid        = UNSTUFF_BITS(resp, 104, 24);
                card->cid.prod_name[0]  = UNSTUFF_BITS(resp, 96, 8);
                card->cid.prod_name[1]  = UNSTUFF_BITS(resp, 88, 8);
                card->cid.prod_name[2]  = UNSTUFF_BITS(resp, 80, 8);
                card->cid.prod_name[3]  = UNSTUFF_BITS(resp, 72, 8);
                card->cid.prod_name[4]  = UNSTUFF_BITS(resp, 64, 8);
                card->cid.prod_name[5]  = UNSTUFF_BITS(resp, 56, 8);
                card->cid.prod_name[6]  = UNSTUFF_BITS(resp, 48, 8);
                card->cid.hwrev         = UNSTUFF_BITS(resp, 44, 4);
                card->cid.fwrev         = UNSTUFF_BITS(resp, 40, 4);
                card->cid.serial        = UNSTUFF_BITS(resp, 16, 24);
                card->cid.month         = UNSTUFF_BITS(resp, 12, 4);
                card->cid.year          = UNSTUFF_BITS(resp, 8, 4) + 1997;
                break;

        case 2: /* MMC v2.0 - v2.2 */
        case 3: /* MMC v3.1 - v3.3 */
        case 4: /* MMC v4 */
                card->cid.manfid        = UNSTUFF_BITS(resp, 120, 8);
                card->cid.oemid         = UNSTUFF_BITS(resp, 104, 16);
                card->cid.prod_name[0]  = UNSTUFF_BITS(resp, 96, 8);
                card->cid.prod_name[1]  = UNSTUFF_BITS(resp, 88, 8);
                card->cid.prod_name[2]  = UNSTUFF_BITS(resp, 80, 8);
                card->cid.prod_name[3]  = UNSTUFF_BITS(resp, 72, 8);
                card->cid.prod_name[4]  = UNSTUFF_BITS(resp, 64, 8);
                card->cid.prod_name[5]  = UNSTUFF_BITS(resp, 56, 8);
                card->cid.serial        = UNSTUFF_BITS(resp, 16, 32);
                card->cid.month         = UNSTUFF_BITS(resp, 12, 4);
                card->cid.year          = UNSTUFF_BITS(resp, 8, 4) + 1997;
                break;

        default:
                printk(KERN_ERR "%s: card has unknown MMCA version %d\n",
                        mmc_hostname(card->host), card->csd.mmca_vsn);
                return -EINVAL;
        }

        return 0;
}

static void mmc_set_erase_size(struct mmc_card *card)
{
        if (card->ext_csd.erase_group_def & 1)
                card->erase_size = card->ext_csd.hc_erase_size;
        else
                card->erase_size = card->csd.erase_size;

        mmc_init_erase(card);
}

/*
 * Given a 128-bit response, decode to our card CSD structure.
 */
static int mmc_decode_csd(struct mmc_card *card)
{
        struct mmc_csd *csd = &card->csd;
        unsigned int e, m, a, b;
        u32 *resp = card->raw_csd;

        /*
         * We only understand CSD structure v1.1 and v1.2.
         * v1.2 has extra information in bits 15, 11 and 10.
         * We also support eMMC v4.4 & v4.41.
         */
        csd->structure = UNSTUFF_BITS(resp, 126, 2);
        if (csd->structure == 0) {
                printk(KERN_ERR "%s: unrecognised CSD structure version %d\n",
                        mmc_hostname(card->host), csd->structure);
                return -EINVAL;
        }

        csd->mmca_vsn    = UNSTUFF_BITS(resp, 122, 4);
        m = UNSTUFF_BITS(resp, 115, 4);
        e = UNSTUFF_BITS(resp, 112, 3);
        csd->tacc_ns     = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
        csd->tacc_clks   = UNSTUFF_BITS(resp, 104, 8) * 100;

        m = UNSTUFF_BITS(resp, 99, 4);
        e = UNSTUFF_BITS(resp, 96, 3);
        csd->max_dtr      = tran_exp[e] * tran_mant[m];
        csd->cmdclass     = UNSTUFF_BITS(resp, 84, 12);

        e = UNSTUFF_BITS(resp, 47, 3);
        m = UNSTUFF_BITS(resp, 62, 12);
        csd->capacity     = (1 + m) << (e + 2);

        csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
        csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
        csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
        csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
        csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
        csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
        csd->write_partial = UNSTUFF_BITS(resp, 21, 1);

        if (csd->write_blkbits >= 9) {
                a = UNSTUFF_BITS(resp, 42, 5);
                b = UNSTUFF_BITS(resp, 37, 5);
                csd->erase_size = (a + 1) * (b + 1);
                csd->erase_size <<= csd->write_blkbits - 9;
        }

        return 0;
}

/*
 * Read and decode extended CSD.
 */
static int mmc_read_ext_csd(struct mmc_card *card)
{
        int err;
        u8 *ext_csd;

        BUG_ON(!card);

        if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
                return 0;

        /*
         * As the ext_csd is so large and mostly unused, we don't store the
         * raw block in mmc_card.
         */
        ext_csd = kmalloc(512, GFP_KERNEL);
        if (!ext_csd) {
                printk(KERN_ERR "%s: could not allocate a buffer to "
                        "receive the ext_csd.\n", mmc_hostname(card->host));
                return -ENOMEM;
        }

        err = mmc_send_ext_csd(card, ext_csd);
        if (err) {
                /* If the host or the card can't do the switch,
                 * fail more gracefully. */
                if ((err != -EINVAL)
                 && (err != -ENOSYS)
                 && (err != -EFAULT))
                        goto out;

                /*
                 * High capacity cards should have this "magic" size
                 * stored in their CSD.
                 */
                if (card->csd.capacity == (4096 * 512)) {
                        printk(KERN_ERR "%s: unable to read EXT_CSD "
                                "on a possible high capacity card. "
                                "Card will be ignored.\n",
                                mmc_hostname(card->host));
                } else {
                        printk(KERN_WARNING "%s: unable to read "
                                "EXT_CSD, performance might "
                                "suffer.\n",
                                mmc_hostname(card->host));
                        err = 0;
                }

                goto out;
        }

        /* Version is coded in the CSD_STRUCTURE byte in the EXT_CSD register */
        if (card->csd.structure == 3) {
                int ext_csd_struct = ext_csd[EXT_CSD_STRUCTURE];
                if (ext_csd_struct > 2) {
                        printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
                                "version %d\n", mmc_hostname(card->host),
                                        ext_csd_struct);
                        err = -EINVAL;
                        goto out;
                }
        }

        card->ext_csd.rev = ext_csd[EXT_CSD_REV];
        if (card->ext_csd.rev > 5) {
                printk(KERN_ERR "%s: unrecognised EXT_CSD revision %d\n",
                        mmc_hostname(card->host), card->ext_csd.rev);
                err = -EINVAL;
                goto out;
        }

        if (card->ext_csd.rev >= 2) {
                card->ext_csd.sectors =
                        ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
                        ext_csd[EXT_CSD_SEC_CNT + 1] << 8 |
                        ext_csd[EXT_CSD_SEC_CNT + 2] << 16 |
                        ext_csd[EXT_CSD_SEC_CNT + 3] << 24;

                /* Cards with density > 2GiB are sector addressed */
                if (card->ext_csd.sectors > (2u * 1024 * 1024 * 1024) / 512)
                        mmc_card_set_blockaddr(card);
        }

        switch (ext_csd[EXT_CSD_CARD_TYPE] & EXT_CSD_CARD_TYPE_MASK) {
        case EXT_CSD_CARD_TYPE_DDR_52 | EXT_CSD_CARD_TYPE_52 |
             EXT_CSD_CARD_TYPE_26:
                card->ext_csd.hs_max_dtr = 52000000;
                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_52;
                break;
        case EXT_CSD_CARD_TYPE_DDR_1_2V | EXT_CSD_CARD_TYPE_52 |
             EXT_CSD_CARD_TYPE_26:
                card->ext_csd.hs_max_dtr = 52000000;
                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_1_2V;
                break;
        case EXT_CSD_CARD_TYPE_DDR_1_8V | EXT_CSD_CARD_TYPE_52 |
             EXT_CSD_CARD_TYPE_26:
                card->ext_csd.hs_max_dtr = 52000000;
                card->ext_csd.card_type = EXT_CSD_CARD_TYPE_DDR_1_8V;
                break;
        case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
                card->ext_csd.hs_max_dtr = 52000000;
                break;
        case EXT_CSD_CARD_TYPE_26:
                card->ext_csd.hs_max_dtr = 26000000;
                break;
        default:
                /* MMC v4 spec says this cannot happen */
                printk(KERN_WARNING "%s: card is mmc v4 but doesn't "
                        "support any high-speed modes.\n",
                        mmc_hostname(card->host));
        }

        if (card->ext_csd.rev >= 3) {
                u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];

                /* Sleep / awake timeout in 100ns units */
                if (sa_shift > 0 && sa_shift <= 0x17)
                        card->ext_csd.sa_timeout =
                                        1 << ext_csd[EXT_CSD_S_A_TIMEOUT];
                card->ext_csd.erase_group_def =
                        ext_csd[EXT_CSD_ERASE_GROUP_DEF];
                card->ext_csd.hc_erase_timeout = 300 *
                        ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT];
                card->ext_csd.hc_erase_size =
                        ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] << 10;
        }

        if (card->ext_csd.rev >= 4) {
                card->ext_csd.sec_trim_mult =
                        ext_csd[EXT_CSD_SEC_TRIM_MULT];
                card->ext_csd.sec_erase_mult =
                        ext_csd[EXT_CSD_SEC_ERASE_MULT];
                card->ext_csd.sec_feature_support =
                        ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
                card->ext_csd.trim_timeout = 300 *
                        ext_csd[EXT_CSD_TRIM_MULT];
        }

        if (ext_csd[EXT_CSD_ERASED_MEM_CONT])
                card->erased_byte = 0xFF;
        else
                card->erased_byte = 0x0;

out:
        kfree(ext_csd);

        return err;
}

MMC_DEV_ATTR(cid, "%08x%08x%08x%08x\n", card->raw_cid[0], card->raw_cid[1],
        card->raw_cid[2], card->raw_cid[3]);
MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
        card->raw_csd[2], card->raw_csd[3]);
MMC_DEV_ATTR(date, "%02d/%04d\n", card->cid.month, card->cid.year);
MMC_DEV_ATTR(erase_size, "%u\n", card->erase_size << 9);
MMC_DEV_ATTR(preferred_erase_size, "%u\n", card->pref_erase << 9);
MMC_DEV_ATTR(fwrev, "0x%x\n", card->cid.fwrev);
MMC_DEV_ATTR(hwrev, "0x%x\n", card->cid.hwrev);
MMC_DEV_ATTR(manfid, "0x%06x\n", card->cid.manfid);
MMC_DEV_ATTR(name, "%s\n", card->cid.prod_name);
MMC_DEV_ATTR(oemid, "0x%04x\n", card->cid.oemid);
MMC_DEV_ATTR(serial, "0x%08x\n", card->cid.serial);

static struct attribute *mmc_std_attrs[] = {
        &dev_attr_cid.attr,
        &dev_attr_csd.attr,
        &dev_attr_date.attr,
        &dev_attr_erase_size.attr,
        &dev_attr_preferred_erase_size.attr,
        &dev_attr_fwrev.attr,
        &dev_attr_hwrev.attr,
        &dev_attr_manfid.attr,
        &dev_attr_name.attr,
        &dev_attr_oemid.attr,
        &dev_attr_serial.attr,
        NULL,
};

static struct attribute_group mmc_std_attr_group = {
        .attrs = mmc_std_attrs,
};

static const struct attribute_group *mmc_attr_groups[] = {
        &mmc_std_attr_group,
        NULL,
};

static struct device_type mmc_type = {
        .groups = mmc_attr_groups,
};

/*
 * 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_init_card(struct mmc_host *host, u32 ocr,
        struct mmc_card *oldcard)
{
        struct mmc_card *card;
        int err, ddr = 0;
        u32 cid[4];
        unsigned int max_dtr;

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

        /*
         * Since we're changing the OCR value, we seem to
         * need to tell some cards to go back to the idle
         * state.  We wait 1ms to give cards time to
         * respond.
         */
        mmc_go_idle(host);

        /* The extra bit indicates that we support high capacity */
        err = mmc_send_op_cond(host, ocr | (1 << 30), NULL);
        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;
        }

        /*
         * Fetch CID from card.
         */
        if (mmc_host_is_spi(host))
                err = mmc_send_cid(host, cid);
        else
                err = mmc_all_send_cid(host, cid);
        if (err)
                goto err;

        if (oldcard) {
                if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0) {
                        err = -ENOENT;
                        goto err;
                }

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

                card->type = MMC_TYPE_MMC;
                card->rca = 1;
                memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
        }

        /*
         * For native busses:  set card RCA and quit open drain mode.
         */
        if (!mmc_host_is_spi(host)) {
                err = mmc_set_relative_addr(card);
                if (err)
                        goto free_card;

                mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
        }

        if (!oldcard) {
                /*
                 * Fetch CSD from card.
                 */
                err = mmc_send_csd(card, card->raw_csd);
                if (err)
                        goto free_card;

                err = mmc_decode_csd(card);
                if (err)
                        goto free_card;
                err = mmc_decode_cid(card);
                if (err)
                        goto free_card;
        }

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

        if (!oldcard) {
                /*
                 * Fetch and process extended CSD.
                 */
                err = mmc_read_ext_csd(card);
                if (err)
                        goto free_card;
                /* Erase size depends on CSD and Extended CSD */
                mmc_set_erase_size(card);
        }

        /*
         * Activate high speed (if supported)
         */
        if ((card->ext_csd.hs_max_dtr != 0) &&
                (host->caps & MMC_CAP_MMC_HIGHSPEED)) {
                err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
                        EXT_CSD_HS_TIMING, 1);
                if (err && err != -EBADMSG)
                        goto free_card;

                if (err) {
                        printk(KERN_WARNING "%s: switch to highspeed failed\n",
                               mmc_hostname(card->host));
                        err = 0;
                } else {
                        mmc_card_set_highspeed(card);
                        mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
                }
        }

        /*
         * Compute bus speed.
         */
        max_dtr = (unsigned int)-1;

        if (mmc_card_highspeed(card)) {
                if (max_dtr > card->ext_csd.hs_max_dtr)
                        max_dtr = card->ext_csd.hs_max_dtr;
        } else if (max_dtr > card->csd.max_dtr) {
                max_dtr = card->csd.max_dtr;
        }

        mmc_set_clock(host, max_dtr);

        /*
         * Indicate DDR mode (if supported).
         */
        if (mmc_card_highspeed(card)) {
                if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_8V)
                        && (host->caps & (MMC_CAP_1_8V_DDR)))
                                ddr = MMC_1_8V_DDR_MODE;
                else if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_2V)
                        && (host->caps & (MMC_CAP_1_2V_DDR)))
                                ddr = MMC_1_2V_DDR_MODE;
        }

        /*
         * Activate wide bus and DDR (if supported).
         */
        if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
            (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
                static unsigned ext_csd_bits[][2] = {
                        { EXT_CSD_BUS_WIDTH_8, EXT_CSD_DDR_BUS_WIDTH_8 },
                        { EXT_CSD_BUS_WIDTH_4, EXT_CSD_DDR_BUS_WIDTH_4 },
                        { EXT_CSD_BUS_WIDTH_1, EXT_CSD_BUS_WIDTH_1 },
                };
                static unsigned bus_widths[] = {
                        MMC_BUS_WIDTH_8,
                        MMC_BUS_WIDTH_4,
                        MMC_BUS_WIDTH_1
                };
                unsigned idx, bus_width = 0;

                if (host->caps & MMC_CAP_8_BIT_DATA)
                        idx = 0;
                else
                        idx = 1;
                for (; idx < ARRAY_SIZE(bus_widths); idx++) {
                        bus_width = bus_widths[idx];
                        if (bus_width == MMC_BUS_WIDTH_1)
                                ddr = 0; /* no DDR for 1-bit width */
                        err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
                                         EXT_CSD_BUS_WIDTH,
                                         ext_csd_bits[idx][0]);
                        if (!err) {
                                /*
                                 * If controller can't handle bus width test,
                                 * use the highest bus width to maintain
                                 * compatibility with previous MMC behavior.
                                 */
                                if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
                                        break;
                                mmc_set_bus_width_ddr(card->host,
                                                      bus_width, MMC_SDR_MODE);
                                err = mmc_bus_test(card, bus_width);
                                if (!err)
                                        break;
                        }
                }

                if (!err && ddr) {
                        err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
                                        EXT_CSD_BUS_WIDTH,
                                        ext_csd_bits[idx][1]);
                }
                if (err) {
                        printk(KERN_WARNING "%s: switch to bus width %d ddr %d "
                                "failed\n", mmc_hostname(card->host),
                                1 << bus_width, ddr);
                        goto free_card;
                } else if (ddr) {
                        mmc_card_set_ddr_mode(card);
                        mmc_set_bus_width_ddr(card->host, bus_width, ddr);
                }
        }

        if (!oldcard)
                host->card = card;

        return 0;

free_card:
        if (!oldcard)
                mmc_remove_card(card);
err:

        return err;
}

/*
 * Host is being removed. Free up the current card.
 */
static void mmc_remove(struct mmc_host *host)
{
        BUG_ON(!host);
        BUG_ON(!host->card);

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

/*
 * Card detection callback from host.
 */
static void mmc_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_send_status(host->card, NULL);

        mmc_release_host(host);

        if (err) {
                mmc_remove(host);

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

/*
 * Suspend callback from host.
 */
static int mmc_suspend(struct mmc_host *host)
{
        BUG_ON(!host);
        BUG_ON(!host->card);

        mmc_claim_host(host);
        if (!mmc_host_is_spi(host))
                mmc_deselect_cards(host);
        host->card->state &= ~MMC_STATE_HIGHSPEED;
        mmc_release_host(host);

        return 0;
}

/*
 * Resume callback from host.
 *
 * This function tries to determine if the same card is still present
 * and, if so, restore all state to it.
 */
static int mmc_resume(struct mmc_host *host)
{
        int err;

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

        mmc_claim_host(host);
        err = mmc_init_card(host, host->ocr, host->card);
        mmc_release_host(host);

        return err;
}

static int mmc_power_restore(struct mmc_host *host)
{
        int ret;

        host->card->state &= ~MMC_STATE_HIGHSPEED;
        mmc_claim_host(host);
        ret = mmc_init_card(host, host->ocr, host->card);
        mmc_release_host(host);

        return ret;
}

static int mmc_sleep(struct mmc_host *host)
{
        struct mmc_card *card = host->card;
        int err = -ENOSYS;

        if (card && card->ext_csd.rev >= 3) {
                err = mmc_card_sleepawake(host, 1);
                if (err < 0)
                        pr_debug("%s: Error %d while putting card into sleep",
                                 mmc_hostname(host), err);
        }

        return err;
}

static int mmc_awake(struct mmc_host *host)
{
        struct mmc_card *card = host->card;
        int err = -ENOSYS;

        if (card && card->ext_csd.rev >= 3) {
                err = mmc_card_sleepawake(host, 0);
                if (err < 0)
                        pr_debug("%s: Error %d while awaking sleeping card",
                                 mmc_hostname(host), err);
        }

        return err;
}

static const struct mmc_bus_ops mmc_ops = {
        .awake = mmc_awake,
        .sleep = mmc_sleep,
        .remove = mmc_remove,
        .detect = mmc_detect,
        .suspend = NULL,
        .resume = NULL,
        .power_restore = mmc_power_restore,
};

static const struct mmc_bus_ops mmc_ops_unsafe = {
        .awake = mmc_awake,
        .sleep = mmc_sleep,
        .remove = mmc_remove,
        .detect = mmc_detect,
        .suspend = mmc_suspend,
        .resume = mmc_resume,
        .power_restore = mmc_power_restore,
};

static void mmc_attach_bus_ops(struct mmc_host *host)
{
        const struct mmc_bus_ops *bus_ops;

        if (!mmc_card_is_removable(host))
                bus_ops = &mmc_ops_unsafe;
        else
                bus_ops = &mmc_ops;
        mmc_attach_bus(host, bus_ops);
}

/*
 * Starting point for MMC card init.
 */
int mmc_attach_mmc(struct mmc_host *host, u32 ocr)
{
        int err;

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

        mmc_attach_bus_ops(host);
        if (host->ocr_avail_mmc)
                host->ocr_avail = host->ocr_avail_mmc;

        /*
         * We need to get OCR a different way for SPI.
         */
        if (mmc_host_is_spi(host)) {
                err = mmc_spi_read_ocr(host, 1, &ocr);
                if (err)
                        goto err;
        }

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

        /*
         * Detect and init the card.
         */
        err = mmc_init_card(host, host->ocr, NULL);
        if (err)
                goto err;

        mmc_release_host(host);

        err = mmc_add_card(host->card);
        if (err)
                goto remove_card;

        return 0;

remove_card:
        mmc_remove_card(host->card);
        host->card = NULL;
        mmc_claim_host(host);
err:
        mmc_detach_bus(host);
        mmc_release_host(host);

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

        return err;
}