mmc.c

嵌入式Linux下SD卡的驱动 驱动主要以三星2410板设计的

/*
 *  linux/drivers/mmc/mmc.c
 *
 *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
 *
 *  SD-Card support:
 *    Copyright (C) 2004 Thomas Kleffel, 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/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/pagemap.h>
#include <linux/err.h>

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

#include "mmc.h"

#ifdef CONFIG_MMC_DEBUG
#define DBG(x...)	printk(KERN_DEBUG x)
#else
#define DBG(x...)	do { } while (0)
#endif

#define CMD_RETRIES	3

/*
 * OCR Bit positions to 10s of Vdd mV.
 */
static const unsigned short mmc_ocr_bit_to_vdd[] = {
	150,	155,	160,	165,	170,	180,	190,	200,
	210,	220,	230,	240,	250,	260,	270,	280,
	290,	300,	310,	320,	330,	340,	350,	360
};

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,
};


/**
 *	mmc_request_done - finish processing an MMC command
 *	@host: MMC host which completed command
 *	@mrq: MMC request which completed
 *
 *	MMC drivers should call this function when they have completed
 *	their processing of a command.  This should be called before the
 *	data part of the command has completed.
 */
void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
{
	struct mmc_command *cmd = mrq->cmd;
	int err = mrq->cmd->error;
	DBG("MMC: req done (%02x): %d: %08x %08x %08x %08x\n", cmd->opcode,
	    err, cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]);

	if (err && cmd->retries) {
		cmd->retries--;
		cmd->error = 0;
		host->ops->request(host, mrq);
	} else if (mrq->done) {
		mrq->done(mrq);
	}
}

EXPORT_SYMBOL(mmc_request_done);

/**
 *	mmc_start_request - start a command on a host
 *	@host: MMC host to start command on
 *	@mrq: MMC request to start
 *
 *	Queue a command on the specified host.  We expect the
 *	caller to be holding the host lock with interrupts disabled.
 */
void
mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
{
	DBG("MMC: starting cmd %02x arg %08x flags %08x\n",
	    mrq->cmd->opcode, mrq->cmd->arg, mrq->cmd->flags);

	WARN_ON(host->card_busy == NULL);

	mrq->cmd->error = 0;
	mrq->cmd->mrq = mrq;
	if (mrq->data) {
		mrq->cmd->data = mrq->data;
		mrq->data->error = 0;
		mrq->data->mrq = mrq;
		if (mrq->stop) {
			mrq->data->stop = mrq->stop;
			mrq->stop->error = 0;
			mrq->stop->mrq = mrq;
		}
	}
	host->ops->request(host, mrq);
}

EXPORT_SYMBOL(mmc_start_request);

static void mmc_wait_done(struct mmc_request *mrq)
{
	complete(mrq->done_data);
}

int mmc_wait_for_req(struct mmc_host *host, struct mmc_request *mrq)
{
	DECLARE_COMPLETION(complete);

	mrq->done_data = &complete;
	mrq->done = mmc_wait_done;

	mmc_start_request(host, mrq);

	wait_for_completion(&complete);

	return 0;
}

EXPORT_SYMBOL(mmc_wait_for_req);

/**
 *	mmc_wait_for_cmd - start a command and wait for completion
 *	@host: MMC host to start command
 *	@cmd: MMC command to start
 *	@retries: maximum number of retries
 *
 *	Start a new MMC command for a host, and wait for the command
 *	to complete.  Return any error that occurred while the command
 *	was executing.  Do not attempt to parse the response.
 */
int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, int retries)
{
	struct mmc_request mrq;

	BUG_ON(host->card_busy == NULL);

	memset(&mrq, 0, sizeof(struct mmc_request));

	memset(cmd->resp, 0, sizeof(cmd->resp));
	cmd->retries = retries;

	mrq.cmd = cmd;
	cmd->data = NULL;

	mmc_wait_for_req(host, &mrq);

	return cmd->error;
}

EXPORT_SYMBOL(mmc_wait_for_cmd);

static int mmc_send_app_cmd(struct mmc_host *host,  u16 rca)
{
	struct mmc_command cmd;

	cmd.opcode = MMC_APP_CMD;
	cmd.arg =((u32)rca)<<16;
	cmd.flags = MMC_RSP_R1;

	return mmc_wait_for_cmd(host, &cmd, 0);
}

int mmc_wait_for_acmd(struct mmc_host *host, u16 rca, struct mmc_command *cmd, int retries)
{
	int err;

	do {
		err = mmc_send_app_cmd(host, rca);
		if(err != MMC_ERR_NONE) continue;

		err = mmc_wait_for_cmd(host, cmd, 0);
		if(err == MMC_ERR_NONE) break;

	} while (retries--);

	return err;
}




/**
 *	__mmc_claim_host - exclusively claim a host
 *	@host: mmc host to claim
 *	@card: mmc card to claim host for
 *
 *	Claim a host for a set of operations.  If a valid card
 *	is passed and this wasn't the last card selected, select
 *	the card before returning.
 *
 *	Note: you should use mmc_card_claim_host or mmc_claim_host.
 */
int __mmc_claim_host(struct mmc_host *host, struct mmc_card *card)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long flags;
	int err = 0;

	add_wait_queue(&host->wq, &wait);
	spin_lock_irqsave(&host->lock, flags);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (host->card_busy == NULL)
			break;
		spin_unlock_irqrestore(&host->lock, flags);
		schedule();
		spin_lock_irqsave(&host->lock, flags);
	}
	set_current_state(TASK_RUNNING);
	host->card_busy = card;
	spin_unlock_irqrestore(&host->lock, flags);
	remove_wait_queue(&host->wq, &wait);

	if (card != (void *)-1 && host->card_selected != card) {
		struct mmc_command cmd;

		host->card_selected = card;

		cmd.opcode = MMC_SELECT_CARD;
		cmd.arg = card->rca << 16;
		cmd.flags = MMC_RSP_R1;

		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
	}

	return err;
}

EXPORT_SYMBOL(__mmc_claim_host);

/**
 *	mmc_release_host - release a host
 *	@host: mmc host to release
 *
 *	Release a MMC host, allowing others to claim the host
 *	for their operations.
 */
void mmc_release_host(struct mmc_host *host)
{
	unsigned long flags;

	BUG_ON(host->card_busy == NULL);

	spin_lock_irqsave(&host->lock, flags);
	host->card_busy = NULL;
	spin_unlock_irqrestore(&host->lock, flags);

	wake_up(&host->wq);
}

EXPORT_SYMBOL(mmc_release_host);

/*
 * Ensure that no card is selected.
 */
static void mmc_deselect_cards(struct mmc_host *host)
{
	struct mmc_command cmd;

	if (host->card_selected) {
		host->card_selected = NULL;

		cmd.opcode = MMC_SELECT_CARD;
		cmd.arg = 0;
		cmd.flags = MMC_RSP_NONE;

		mmc_wait_for_cmd(host, &cmd, 0);
	}
}


static inline void mmc_delay(unsigned int ms)
{
	if (ms < HZ / 1000) {
		yield();
		mdelay(ms);
	} else {
		msleep_interruptible (ms);
	}
}

#if 0 /* UNUSED */
/*
 * Mask off any voltages we don't support and select
 * the lowest voltage
 */
static u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
{
	int bit;

	ocr &= host->ocr_avail;

	bit = ffs(ocr);
	if (bit) {
		bit -= 1;

		ocr = 3 << bit;

		host->ios.vdd = bit;
		host->ops->set_ios(host, &host->ios);
	} else {
		ocr = 0;
	}

	return ocr;
}
#endif

#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 void mmc_decode_cid(struct mmc_card *card)
{
	u32 *resp = card->raw_cid;

	memset(&card->cid, 0, sizeof(struct mmc_cid));

	/*
	 * The selection of the format here is guesswork based upon
	 * information people have sent to date.
	 */
	if(card->sd) {
		if(card->csd.csd_vers != SD_CSDV_1) {
			DBG("%s: card has unknown SD-MMCA version %d\n", mmc_hostname(card->host), card->csd.spec_vers);
			mmc_card_set_bad(card);
		} else {
			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]  = 0;
			card->cid.prod_name[6]  = 0;
			card->cid.hwrev		= UNSTUFF_BITS(resp,  60,  4);
			card->cid.fwrev		= UNSTUFF_BITS(resp,  56,  4);
			card->cid.serial	= UNSTUFF_BITS(resp,  24, 32);
			card->cid.month		= UNSTUFF_BITS(resp,  12,  4);
			card->cid.year		= UNSTUFF_BITS(resp,   8,  4) + 2000;
		}
	} else { /* if(card->sd) */
	switch (card->csd.csd_vers) {
	case 0: /* MMC v1.? */
	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.x ? */
	case 3: /* MMC v3.x ? */
		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("%s: card has unknown MMCA version %d\n",
			mmc_hostname(card->host), card->csd.csd_vers);
		mmc_card_set_bad(card);
		break;
	}
	} /* if(card->sd) */
}

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

	if(card->sd) {
		/*
		* We only understand SD-CSD structure v1.0.
		*/
		csd->sd=1;
		csd->csd_vers = UNSTUFF_BITS(resp, 126, 2);
		if(csd->csd_vers != SD_CSDV_1) {
			printk("%s: unrecognised SD-CSD structure version %d\n",
				mmc_hostname(card->host), csd->csd_vers);
			mmc_card_set_bad(card);
			return;
		}

		csd->spec_vers 		= 0;
		csd->taac		= UNSTUFF_BITS(resp, 112, 8);
		csd->nsac		= UNSTUFF_BITS(resp, 104, 8);
		csd->tran_speed		= UNSTUFF_BITS(resp,  96, 8);
		csd->ccc		= UNSTUFF_BITS(resp,  84,12);
		csd->read_bl_len	= UNSTUFF_BITS(resp,  80, 4);
		csd->read_bl_partial	= UNSTUFF_BITS(resp,  79, 1);
		csd->write_blk_misalign	= UNSTUFF_BITS(resp,  78, 1);
		csd->read_blk_misalign	= UNSTUFF_BITS(resp,  77, 1);
		csd->dsr_imp		= UNSTUFF_BITS(resp,  76, 1);
		csd->c_size		= UNSTUFF_BITS(resp,  62,12);
		csd->vdd_r_curr_min	= UNSTUFF_BITS(resp,  69, 3);
		csd->vdd_r_curr_max	= UNSTUFF_BITS(resp,  56, 3);
		csd->vdd_w_curr_min	= UNSTUFF_BITS(resp,  53, 3);
		csd->vdd_w_curr_max	= UNSTUFF_BITS(resp,  50, 3);
		csd->c_size_mult	= UNSTUFF_BITS(resp,  47, 3);
		csd->erase.sd10.erase_blk_en	= UNSTUFF_BITS(resp,  46, 1);
		csd->erase.sd10.erase_blk_size= UNSTUFF_BITS(resp,  39, 7);
		csd->wp_grp_size	= UNSTUFF_BITS(resp,  32, 7);
		csd->wp_grp_enable	= UNSTUFF_BITS(resp,  31, 1);
		csd->r2w_factor		= UNSTUFF_BITS(resp,  26, 3);
		csd->write_bl_len	= UNSTUFF_BITS(resp,  22, 4);
		csd->write_bl_partial	= UNSTUFF_BITS(resp,  21, 1);
		csd->file_format_grp	= UNSTUFF_BITS(resp,  15, 1);
		csd->copy		= UNSTUFF_BITS(resp,  14, 1);
		csd->perm_write_protect	= UNSTUFF_BITS(resp,  13, 1);
		csd->tmp_write_protect	= UNSTUFF_BITS(resp,  12, 1);
		csd->file_format	= UNSTUFF_BITS(resp,  10, 1);
		csd->ecc		= UNSTUFF_BITS(resp,   1, 7);

		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];

		e = UNSTUFF_BITS(resp, 47, 3);
		m = UNSTUFF_BITS(resp, 62, 12);
		csd->capacity	  = (1 + m) << (e + 2);
	} else { /* if(card->sd) { */
	/*
	 * We only understand CSD structure v1.1 and v2.
	 * v2 has extra information in bits 15, 11 and 10.
	 */
	csd->sd=0;
	csd_struct = UNSTUFF_BITS(resp, 126, 2);
	csd->csd_vers = csd_struct;
	if (csd_struct != 1 && csd_struct != 2) {
		printk("%s: unrecognised CSD structure version %d\n",
			mmc_hostname(card->host), csd_struct);
		mmc_card_set_bad(card);
		return;
	}

	csd->spec_vers	 = 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->ccc	  = 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_bl_len = UNSTUFF_BITS(resp, 80, 4);
	} /* if(card->sd) { */
}

/*
 * Locate a MMC card on this MMC host given a raw CID.
 */
static struct mmc_card *mmc_find_card(struct mmc_host *host, u32 *raw_cid)
{
	struct mmc_card *card;

	list_for_each_entry(card, &host->cards, node) {
		if (memcmp(card->raw_cid, raw_cid, sizeof(card->raw_cid)) == 0)
			return card;
	}
	return NULL;
}