mmc: dw_mmc: support the DDR mode

Support the DDR mode at dw-mmc controller

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/mmc/dw_mmc.c

@@ -284,8 +284,8 @@ static int dwmci_setup_bus(struct dwmci_host *host, u32 freq)
 
 static void dwmci_set_ios(struct mmc *mmc)
 {
-	struct dwmci_host *host = mmc->priv;
-	u32 ctype;
+	struct dwmci_host *host = (struct dwmci_host *)mmc->priv;
+	u32 ctype, regs;
 
 	debug("Buswidth = %d, clock: %d\n",mmc->bus_width, mmc->clock);
 
@@ -304,6 +304,14 @@ static void dwmci_set_ios(struct mmc *mmc)
 
 	dwmci_writel(host, DWMCI_CTYPE, ctype);
 
+	regs = dwmci_readl(host, DWMCI_UHS_REG);
+	if (mmc->card_caps & MMC_MODE_DDR_52MHz)
+		regs |= DWMCI_DDR_MODE;
+	else
+		regs &= DWMCI_DDR_MODE;
+
+	dwmci_writel(host, DWMCI_UHS_REG, regs);
+
 	if (host->clksel)
 		host->clksel(host);
 }

include/dwmmc.h

@@ -123,6 +123,9 @@
 #define DWMCI_BMOD_IDMAC_FB	(1 << 1)
 #define DWMCI_BMOD_IDMAC_EN	(1 << 7)
 
+/* UHS register */
+#define DWMCI_DDR_MODE	(1 << 16)
+
 /* quirks */
 #define DWMCI_QUIRK_DISABLE_SMU		(1 << 0)