SD : Updated CMD 6 implememtation.

For setting high speed in SD card,
First CMD 6 (Switch) is send to check if card supports High Speed and
Second command is send to switch card to high speed mode.

In current inplementation, CMD 6 was sent only once to switch the
card into HS mode without checking if card supports HS or not, which is
not as per specification and also we are not setting the HS i.e. 50000000
but directly asking the card to switch to 26000000 which is incorrect as
SD card supports either 25000000 or 50000000.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
This commit is contained in:
Meenakshi Aggarwal
2017-09-07 19:47:53 +05:30
committed by Leif Lindholm
parent 3d43616632
commit ea21f1d98d
2 changed files with 57 additions and 6 deletions

View File

@@ -64,6 +64,14 @@
#define EMMC_CMD6_ARG_VALUE(x) (((x) & 0xFF) << 8)
#define EMMC_CMD6_ARG_CMD_SET(x) (((x) & 0x7) << 0)
#define SWITCH_CMD_DATA_LENGTH 64
#define SD_HIGH_SPEED_SUPPORTED 0x20000
#define SD_DEFAULT_SPEED 25000000
#define SD_HIGH_SPEED 50000000
#define SWITCH_CMD_SUCCESS_MASK 0x0f000000
#define BUSWIDTH_4 4
typedef enum {
UNKNOWN_CARD,
MMC_CARD, //MMC card