drivers/mmc/core/mmc.c - kernel/msm-4.19 - Gitiles

 /*
  *  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_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;
 	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);

 	/*
 	 * Activate wide bus (if supported).
 	 */
 	if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
 	    (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
 		unsigned ext_csd_bit, bus_width;

 		if (host->caps & MMC_CAP_8_BIT_DATA) {
 			ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
 			bus_width = MMC_BUS_WIDTH_8;
 		} else {
 			ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
 			bus_width = MMC_BUS_WIDTH_4;
 		}

 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 				 EXT_CSD_BUS_WIDTH, ext_csd_bit);

 		if (err && err != -EBADMSG)
 			goto free_card;

 		if (err) {
 			printk(KERN_WARNING "%s: switch to bus width %d "
 			       "failed\n", mmc_hostname(card->host),
 			       1 << bus_width);
 			err = 0;
 		} else {
 			mmc_set_bus_width(card->host, bus_width);
 		}
 	}

 	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 void mmc_power_restore(struct mmc_host *host)
 {
 	host->card->state &= ~MMC_STATE_HIGHSPEED;
 	mmc_claim_host(host);
 	mmc_init_card(host, host->ocr, host->card);
 	mmc_release_host(host);
 }

 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);

 	/*
 	 * 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;
 }
	/*
	* 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_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;
	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);

	/*
	* Activate wide bus (if supported).
	*/
	if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
	(host->caps & (MMC_CAP_4_BIT_DATA \| MMC_CAP_8_BIT_DATA))) {
	unsigned ext_csd_bit, bus_width;

	if (host->caps & MMC_CAP_8_BIT_DATA) {
	ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
	bus_width = MMC_BUS_WIDTH_8;
	} else {
	ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
	bus_width = MMC_BUS_WIDTH_4;
	}

	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
	EXT_CSD_BUS_WIDTH, ext_csd_bit);

	if (err && err != -EBADMSG)
	goto free_card;

	if (err) {
	printk(KERN_WARNING "%s: switch to bus width %d "
	"failed\n", mmc_hostname(card->host),
	1 << bus_width);
	err = 0;
	} else {
	mmc_set_bus_width(card->host, bus_width);
	}
	}

	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 void mmc_power_restore(struct mmc_host *host)
	{
	host->card->state &= ~MMC_STATE_HIGHSPEED;
	mmc_claim_host(host);
	mmc_init_card(host, host->ocr, host->card);
	mmc_release_host(host);
	}

	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);

	/*
	* 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;
	}