[PATCH] sd: SCR register

Read the SD specific SCR register from the card.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Pierre Ossman 2005-09-06 15:18:53 -07:00 committed by Linus Torvalds
parent a00fc09029
commit b57c43ad81
2 changed files with 142 additions and 10 deletions

View File

@ -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);
}

View File

@ -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)