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Commit b57c43ad authored by Pierre Ossman's avatar Pierre Ossman Committed by Linus Torvalds
Browse files

[PATCH] sd: SCR register 



Read the SD specific SCR register from the card.

Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a00fc090

drivers/mmc/mmc.c

+133 −10
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 
#include <linux/delay.h>

#include <linux/pagemap.h>

#include <linux/err.h>

#include <asm/scatterlist.h>

#include <linux/scatterlist.h>



#include <linux/mmc/card.h>

#include <linux/mmc/host.h>
@@ -246,6 +248,8 @@ int mmc_wait_for_app_cmd(struct mmc_host *host, unsigned int rca, 


EXPORT_SYMBOL(mmc_wait_for_app_cmd);



static int mmc_select_card(struct mmc_host *host, struct mmc_card *card);



/**

 *	__mmc_claim_host - exclusively claim a host

 *	@host: mmc host to claim
@@ -278,16 +282,10 @@ int __mmc_claim_host(struct mmc_host *host, struct mmc_card *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);

	if (card != (void *)-1) {

		err = mmc_select_card(host, card);

		if (err != MMC_ERR_NONE)

			return err;

	}



	return err;
@@ -317,6 +315,29 @@ void mmc_release_host(struct mmc_host *host) 


EXPORT_SYMBOL(mmc_release_host);



static int mmc_select_card(struct mmc_host *host, struct mmc_card *card)

{

	int err;

	struct mmc_command cmd;



	BUG_ON(host->card_busy == NULL);



	if (host->card_selected == card)

		return MMC_ERR_NONE;



	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);

	if (err != MMC_ERR_NONE)

		return err;



	return MMC_ERR_NONE;

}



/*

 * Ensure that no card is selected.

 */
@@ -525,6 +546,32 @@ static void mmc_decode_csd(struct mmc_card *card) 
	}

}



/*

 * Given a 64-bit response, decode to our card SCR structure.

 */

static void mmc_decode_scr(struct mmc_card *card)

{

	struct sd_scr *scr = &card->scr;

	unsigned int scr_struct;

	u32 resp[4];



	BUG_ON(!mmc_card_sd(card));



	resp[3] = card->raw_scr[1];

	resp[2] = card->raw_scr[0];



	scr_struct = UNSTUFF_BITS(resp, 60, 4);

	if (scr_struct != 0) {

		printk("%s: unrecognised SCR structure version %d\n",

			mmc_hostname(card->host), scr_struct);

		mmc_card_set_bad(card);

		return;

	}



	scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);

	scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);

}



/*

 * Locate a MMC card on this MMC host given a raw CID.

 */
@@ -789,6 +836,79 @@ static void mmc_read_csds(struct mmc_host *host) 
	}

}



static void mmc_read_scrs(struct mmc_host *host)

{

	int err;

	struct mmc_card *card;



	struct mmc_request mrq;

	struct mmc_command cmd;

	struct mmc_data data;



	struct scatterlist sg;



	list_for_each_entry(card, &host->cards, node) {

		if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))

			continue;

		if (!mmc_card_sd(card))

			continue;



		err = mmc_select_card(host, card);

		if (err != MMC_ERR_NONE) {

			mmc_card_set_dead(card);

			continue;

		}



		memset(&cmd, 0, sizeof(struct mmc_command));



		cmd.opcode = MMC_APP_CMD;

		cmd.arg = card->rca << 16;

		cmd.flags = MMC_RSP_R1;



		err = mmc_wait_for_cmd(host, &cmd, 0);

		if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD)) {

			mmc_card_set_dead(card);

			continue;

		}



		memset(&cmd, 0, sizeof(struct mmc_command));



		cmd.opcode = SD_APP_SEND_SCR;

		cmd.arg = 0;

		cmd.flags = MMC_RSP_R1;



		memset(&data, 0, sizeof(struct mmc_data));



		data.timeout_ns = card->csd.tacc_ns * 10;

		data.timeout_clks = card->csd.tacc_clks * 10;

		data.blksz_bits = 3;

		data.blocks = 1;

		data.flags = MMC_DATA_READ;

		data.sg = &sg;

		data.sg_len = 1;



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



		mrq.cmd = &cmd;

		mrq.data = &data;



		sg_init_one(&sg, (u8*)card->raw_scr, 8);



		err = mmc_wait_for_req(host, &mrq);

		if (err != MMC_ERR_NONE) {

			mmc_card_set_dead(card);

			continue;

		}



		card->raw_scr[0] = ntohl(card->raw_scr[0]);

		card->raw_scr[1] = ntohl(card->raw_scr[1]);



		mmc_decode_scr(card);

	}



	mmc_deselect_cards(host);

}



static unsigned int mmc_calculate_clock(struct mmc_host *host)

{

	struct mmc_card *card;
@@ -912,6 +1032,9 @@ static void mmc_setup(struct mmc_host *host) 
	host->ops->set_ios(host, &host->ios);



	mmc_read_csds(host);



	if (host->mode == MMC_MODE_SD)

		mmc_read_scrs(host);

}

include/linux/mmc/card.h

+9 −0
Original line number Diff line number Diff line
@@ -33,6 +33,13 @@ struct mmc_csd { 
	unsigned int		capacity;

};



struct sd_scr {

	unsigned char		sda_vsn;

	unsigned char		bus_widths;

#define SD_SCR_BUS_WIDTH_1	(1<<0)

#define SD_SCR_BUS_WIDTH_4	(1<<2)

};



struct mmc_host;



/*
@@ -51,8 +58,10 @@ struct mmc_card { 
#define MMC_STATE_READONLY	(1<<4)		/* card is read-only */

	u32			raw_cid[4];	/* raw card CID */

	u32			raw_csd[4];	/* raw card CSD */

	u32			raw_scr[2];	/* raw card SCR */

	struct mmc_cid		cid;		/* card identification */

	struct mmc_csd		csd;		/* card specific */

	struct sd_scr		scr;		/* extra SD information */

};



#define mmc_card_present(c)	((c)->state & MMC_STATE_PRESENT)