diff options
| author | Yong Ding <yongd@marvell.com> | 2012-05-15 13:09:43 +0800 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-06-06 09:22:53 -0400 |
| commit | 2a0fe914a38745f5b03534c4e4f4056cbd6978b8 (patch) | |
| tree | b341420c0fc9a3eaf0c62a431d495ff67742e5a0 | |
| parent | 693e5e2025278d90e1427f037e5ec8ea1ec7d5c4 (diff) | |
mmc: sdio: fix setting card data bus width as 4-bit
SDIO_CCCR_IF[1:0] in SDIO card is used for card data bus width
setting as below:
00b: 1-bit bus
01b: Reserved
10b: 4-bit bus
11b: 8-bit bus (only for embedded SDIO)
And sdio_enable_wide is for setting data bus width as 4-bit.
But currently, it first reads the register, second OR' 1b with
SDIO_CCCR_IF[1], and then writes it back.
As we can see, this is based on such assumption that the
SDIO_CCCR_IF[0] is always 0. Apparently, this is not right.
Signed-off-by: Yong Ding <yongd@marvell.com>
Acked-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
| -rw-r--r-- | drivers/mmc/core/sdio.c | 6 | ||||
| -rw-r--r-- | include/linux/mmc/sdio.h | 2 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c index 13d0e95380ab..41c5fd8848f4 100644 --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -218,6 +218,12 @@ static int sdio_enable_wide(struct mmc_card *card) if (ret) return ret; + if ((ctrl & SDIO_BUS_WIDTH_MASK) == SDIO_BUS_WIDTH_RESERVED) + pr_warning("%s: SDIO_CCCR_IF is invalid: 0x%02x\n", + mmc_hostname(card->host), ctrl); + + /* set as 4-bit bus width */ + ctrl &= ~SDIO_BUS_WIDTH_MASK; ctrl |= SDIO_BUS_WIDTH_4BIT; ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL); diff --git a/include/linux/mmc/sdio.h b/include/linux/mmc/sdio.h index c9fe66c58f8f..17446d3c3602 100644 --- a/include/linux/mmc/sdio.h +++ b/include/linux/mmc/sdio.h @@ -98,7 +98,9 @@ #define SDIO_CCCR_IF 0x07 /* bus interface controls */ +#define SDIO_BUS_WIDTH_MASK 0x03 /* data bus width setting */ #define SDIO_BUS_WIDTH_1BIT 0x00 +#define SDIO_BUS_WIDTH_RESERVED 0x01 #define SDIO_BUS_WIDTH_4BIT 0x02 #define SDIO_BUS_ECSI 0x20 /* Enable continuous SPI interrupt */ #define SDIO_BUS_SCSI 0x40 /* Support continuous SPI interrupt */ |