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>

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 62c8440..58476c1 100644 (file)
--- 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 5dd55a7..23c662a 100644 (file)
--- 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))