Some SD controllers need specific settings for HS400 mode
before the speed mode is been switching from DDR mode to
HS400 mode. This patch is to add prepare_ddr_to_hs400 callback
for this.
Signed-off-by: Yinbo Zhu <yinbo.zhu@xxxxxxx>
---
Change in v2:
Separate from "hs400 mode support" as a mmc patch.
drivers/mmc/core/mmc.c | 3 +++
include/linux/mmc/host.h | 1 +
2 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 4f4a627..a5a3b3b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1148,6 +1148,9 @@ static int mmc_select_hs400(struct mmc_card *card)
goto out_err;
/* Switch card to DDR */
+ if (host->ops->prepare_ddr_to_hs400)
+ host->ops->prepare_ddr_to_hs400(host);
+
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH,
EXT_CSD_DDR_BUS_WIDTH_8,
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 0b24394..c97ffd6 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -146,6 +146,7 @@ struct mmc_host_ops {
/* Prepare HS400 target operating frequency depending host driver */
int (*prepare_hs400_tuning)(struct mmc_host *host, struct mmc_ios *ios);
+ int (*prepare_ddr_to_hs400)(struct mmc_host *host);
/* Prepare enhanced strobe depending host driver */
void (*hs400_enhanced_strobe)(struct mmc_host *host,
struct mmc_ios *ios);
--
1.7.1
