mmc: dw_mmc: support DDR mode

This patch adds DDR mode support to dw_mmc.

If we set any bit in UHS_REG bit[16:31], the card of that slot is
supported for DDR mode.  For example, if UHS_REG[16] is set, card
number 0 is DDR mode.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 9 insertions, 1 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 62c8440ff04b..58476c1bb056 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -662,6 +662,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
         struct dw_mci_slot *slot = mmc_priv(mmc);
+        u32 regs;
 
         /* set default 1 bit mode */
         slot->ctype = SDMMC_CTYPE_1BIT;
@@ -678,6 +679,13 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                 break;
         }
 
+        /* DDR mode set */
+        if (ios->ddr) {
+                regs = mci_readl(slot->host, UHS_REG);
+                regs |= (0x1 << slot->id) << 16;
+                mci_writel(slot->host, UHS_REG, regs);
+        }
+
         if (ios->clock) {
                 /*
                  * Use mirror of ios->clock to prevent race with mmc
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 5dd55a75233d..23c662af5616 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -43,6 +43,7 @@
 #define SDMMC_USRID             0x068
 #define SDMMC_VERID             0x06c
 #define SDMMC_HCON              0x070
+#define SDMMC_UHS_REG           0x074
 #define SDMMC_BMOD              0x080
 #define SDMMC_PLDMND            0x084
 #define SDMMC_DBADDR            0x088
@@ -51,7 +52,6 @@
 #define SDMMC_DSCADDR           0x094
 #define SDMMC_BUFADDR           0x098
 #define SDMMC_DATA              0x100
-#define SDMMC_DATA_ADR          0x100
 
 /* shift bit field */
 #define _SBF(f, v)              ((v) << (f))