[U-Boot] [PATCH 6/9] mmc: support the DDR mode for eMMC

Jaehoon Chung
2014-03-27T08:54:46Z

Support the DDR mode.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
drivers/mmc/mmc.c | 15 ++++++++++++---
include/mmc.h | 7 +++++++
2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index bac07c2..2874780 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -163,6 +163,9 @@ int mmc_set_blocklen(struct mmc *mmc, int len)
{
struct mmc_cmd cmd;

+ if (mmc->card_caps & MMC_MODE_DDR_52MHz)
+ return 0;
+
cmd.cmdidx = MMC_CMD_SET_BLOCKLEN;
cmd.resp_type = MMC_RSP_R1;
cmd.cmdarg = len;
@@ -518,9 +521,11 @@ static int mmc_change_freq(struct mmc *mmc)
return 0;

/* High Speed is set, there are two types: 52MHz and 26MHz */
- if (cardtype & EXT_CSD_CARD_TYPE_52)
+ if (cardtype & EXT_CSD_CARD_TYPE_52) {
+ if (cardtype & EXT_CSD_CARD_TYPE_DDR_52)
+ mmc->card_caps |= MMC_MODE_DDR_52MHz;
mmc->card_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
- else
+ } else
mmc->card_caps |= MMC_MODE_HS;

return 0;
@@ -1057,6 +1062,8 @@ static int mmc_startup(struct mmc *mmc)

/* An array of possible bus widths in order of preference */
static unsigned ext_csd_bits[] = {
+ EXT_CSD_DDR_BUS_WIDTH_8,
+ EXT_CSD_DDR_BUS_WIDTH_4,
EXT_CSD_BUS_WIDTH_8,
EXT_CSD_BUS_WIDTH_4,
EXT_CSD_BUS_WIDTH_1,
@@ -1064,13 +1071,15 @@ static int mmc_startup(struct mmc *mmc)

/* An array to map CSD bus widths to host cap bits */
static unsigned ext_to_hostcaps[] = {
+ [EXT_CSD_DDR_BUS_WIDTH_4] = MMC_MODE_DDR_52MHz,
+ [EXT_CSD_DDR_BUS_WIDTH_8] = MMC_MODE_DDR_52MHz,
[EXT_CSD_BUS_WIDTH_4] = MMC_MODE_4BIT,
[EXT_CSD_BUS_WIDTH_8] = MMC_MODE_8BIT,
};

/* An array to map chosen bus width to an integer */
static unsigned widths[] = {
- 8, 4, 1,
+ 8, 4, 8, 4, 1,
};

for (idx=0; idx < ARRAY_SIZE(ext_csd_bits); idx++) {
diff --git a/include/mmc.h b/include/mmc.h
index 6725ac8..5120d17 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -37,6 +37,7 @@
#define MMC_MODE_8BIT (1 << 3)
#define MMC_MODE_SPI (1 << 4)
#define MMC_MODE_HC (1 << 5)
+#define MMC_MODE_DDR_52MHz (1 << 6)

#define SD_DATA_4BIT 0x00040000

@@ -167,10 +168,16 @@

#define EXT_CSD_CARD_TYPE_26 (1 << 0) /* Card can run at 26MHz */
#define EXT_CSD_CARD_TYPE_52 (1 << 1) /* Card can run@52MHz */
+#define EXT_CSD_CARD_TYPE_DDR_1_8V (1 << 2)
+#define EXT_CSD_CARD_TYPE_DDR_1_2V (1 << 3)
+#define EXT_CSD_CARD_TYPE_DDR_52 (EXT_CSD_CARD_TYPE_DDR_1_8V \
+ | EXT_CSD_CARD_TYPE_DDR_1_2V)

#define EXT_CSD_BUS_WIDTH_1 0 /* Card is in 1 bit mode */
#define EXT_CSD_BUS_WIDTH_4 1 /* Card is in 4 bit mode */
#define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */
+#define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */
+#define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */

#define EXT_CSD_BOOT_ACK_ENABLE (1 << 6)
#define EXT_CSD_BOOT_PARTITION_ENABLE (1 << 3)
--
1.7.9.5