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mmc: Add 8-bit bus width support 

Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
hifive-unleashed-5.1
Jarkko Lavinen 2008-11-17 14:35:21 +02:00 committed by Pierre Ossman
parent 35ff8554d1
commit b30f8af335
2 changed files with 16 additions and 4 deletions
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18
drivers/mmc/core/mmc.c
View File

@ -434,13 +434,24 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
* Activate wide bus (if supported).
*/
if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
(host->caps & MMC_CAP_4_BIT_DATA)) {
(host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
unsigned ext_csd_bit, bus_width;
if (host->caps & MMC_CAP_8_BIT_DATA) {
ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
bus_width = MMC_BUS_WIDTH_8;
} else {
ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
bus_width = MMC_BUS_WIDTH_4;
}
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_4);
EXT_CSD_BUS_WIDTH, ext_csd_bit);
if (err)
goto free_card;
mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
mmc_set_bus_width(card->host, bus_width);
}
if (!oldcard)
@ -624,4 +635,3 @@ err:
return err;
}

2
include/linux/mmc/host.h
View File

@ -41,6 +41,7 @@ struct mmc_ios {
#define MMC_BUS_WIDTH_1 0
#define MMC_BUS_WIDTH_4 2
#define MMC_BUS_WIDTH_8 3
unsigned char timing; /* timing specification used */
@ -116,6 +117,7 @@ struct mmc_host {
#define MMC_CAP_SDIO_IRQ (1 << 3) /* Can signal pending SDIO IRQs */
#define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */
#define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */
#define MMC_CAP_8_BIT_DATA (1 << 6) /* Can the host do 8 bit transfers */
/* host specific block data */
unsigned int max_seg_size; /* see blk_queue_max_segment_size */