path: root/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/stat.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"
#include "sd_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:
		pr_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) {
		pr_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 extended CSD.
 */
static int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd)
{
	int err;
	u8 *ext_csd;

	BUG_ON(!card);
	BUG_ON(!new_ext_csd);

	*new_ext_csd = NULL;

	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) {
		pr_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) {
		kfree(ext_csd);
		*new_ext_csd = NULL;

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

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

	return err;
}

/*
 * Decode extended CSD.
 */
static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
{
	int err = 0, idx;
	unsigned int part_size;
	u8 hc_erase_grp_sz = 0, hc_wp_grp_sz = 0;

	BUG_ON(!card);

	if (!ext_csd)
		return 0;

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

	card->ext_csd.rev = ext_csd[EXT_CSD_REV];
	if (card->ext_csd.rev > 6) {
		pr_err("%s: unrecognised EXT_CSD revision %d\n",
			mmc_hostname(card->host), card->ext_csd.rev);
		err = -EINVAL;
		goto out;
	}

	card->ext_csd.raw_sectors[0] = ext_csd[EXT_CSD_SEC_CNT + 0];
	card->ext_csd.raw_sectors[1] = ext_csd[EXT_CSD_SEC_CNT + 1];
	card->ext_csd.raw_sectors[2] = ext_csd[EXT_CSD_SEC_CNT + 2];
	card->ext_csd.raw_sectors[3] = ext_csd[EXT_CSD_SEC_CNT + 3];
	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