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authorPierre Ossman <drzeus@drzeus.cx>2006-11-08 23:03:10 +0100
committerPierre Ossman <drzeus@drzeus.cx>2006-12-01 18:53:37 +0100
commit7ccd266e676a3f0c6f8f897f58b684cac3dd1650 (patch)
treeaba8632fc523c5c663a56876ce67c580ce8d38eb /drivers
parent73778120c4088a0a7b59c4c378904f7a230b4820 (diff)
mmc: Support for high speed SD cards
Modern SD cards support a clock speed of 50 MHz. Make sure we test for this capability and do the song and dance required to activate it. Activating high speed support actually modifies the TRAN_SPEED field of the CSD. But as the spec says that the cards must report 50 MHz, we might as well skip re-reading the CSD. Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/mmc.c122
1 files changed, 118 insertions, 4 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 82b7643c165..9d190022a49 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1157,6 +1157,116 @@ static void mmc_read_scrs(struct mmc_host *host)
mmc_deselect_cards(host);
}
+static void mmc_read_switch_caps(struct mmc_host *host)
+{
+ int err;
+ struct mmc_card *card;
+ struct mmc_request mrq;
+ struct mmc_command cmd;
+ struct mmc_data data;
+ unsigned char *status;
+ struct scatterlist sg;
+
+ status = kmalloc(64, GFP_KERNEL);
+ if (!status) {
+ printk(KERN_WARNING "%s: Unable to allocate buffer for "
+ "reading switch capabilities.\n",
+ mmc_hostname(host));
+ return;
+ }
+
+ list_for_each_entry(card, &host->cards, node) {
+ if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
+ continue;
+ if (!mmc_card_sd(card))
+ continue;
+ if (card->scr.sda_vsn < SCR_SPEC_VER_1)
+ 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 = SD_SWITCH;
+ cmd.arg = 0x00FFFFF1;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+ memset(&data, 0, sizeof(struct mmc_data));
+
+ mmc_set_data_timeout(&data, card, 0);
+
+ data.blksz = 64;
+ 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, status, 64);
+
+ mmc_wait_for_req(host, &mrq);
+
+ if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
+ mmc_card_set_dead(card);
+ continue;
+ }
+
+ if (status[13] & 0x02)
+ card->sw_caps.hs_max_dtr = 50000000;
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+
+ cmd.opcode = SD_SWITCH;
+ cmd.arg = 0x80FFFFF1;
+ cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+ memset(&data, 0, sizeof(struct mmc_data));
+
+ mmc_set_data_timeout(&data, card, 0);
+
+ data.blksz = 64;
+ 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, status, 64);
+
+ mmc_wait_for_req(host, &mrq);
+
+ if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
+ mmc_card_set_dead(card);
+ continue;
+ }
+
+ if ((status[16] & 0xF) != 1) {
+ printk(KERN_WARNING "%s: Problem switching card "
+ "into high-speed mode!\n",
+ mmc_hostname(host));
+ continue;
+ }
+
+ mmc_card_set_highspeed(card);
+ }
+
+ kfree(status);
+
+ mmc_deselect_cards(host);
+}
+
static unsigned int mmc_calculate_clock(struct mmc_host *host)
{
struct mmc_card *card;
@@ -1164,9 +1274,12 @@ static unsigned int mmc_calculate_clock(struct mmc_host *host)
list_for_each_entry(card, &host->cards, node)
if (!mmc_card_dead(card)) {
- if (mmc_card_highspeed(card)) {
+ if (mmc_card_highspeed(card) && mmc_card_sd(card)) {
+ if (max_dtr > card->sw_caps.hs_max_dtr)
+ max_dtr = card->sw_caps.hs_max_dtr;
+ } else if (mmc_card_highspeed(card) && !mmc_card_sd(card)) {
if (max_dtr > card->ext_csd.hs_max_dtr)
- 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;
}
@@ -1288,9 +1401,10 @@ static void mmc_setup(struct mmc_host *host)
mmc_read_csds(host);
- if (host->mode == MMC_MODE_SD)
+ if (host->mode == MMC_MODE_SD) {
mmc_read_scrs(host);
- else
+ mmc_read_switch_caps(host);
+ } else
mmc_process_ext_csds(host);
}