sdhci: 8-bit data transfer width support

Some host controllers such as s5pc110 support the WIDE8 feature.
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/sdhci.c

@@ -1159,6 +1159,11 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
 
+	if (ios->bus_width == MMC_BUS_WIDTH_8)
+		ctrl |= SDHCI_CTRL_8BITBUS;
+	else
+		ctrl &= ~SDHCI_CTRL_8BITBUS;
+
 	if (ios->bus_width == MMC_BUS_WIDTH_4)
 		ctrl |= SDHCI_CTRL_4BITBUS;
 	else

drivers/mmc/host/sdhci.h

@@ -72,6 +72,7 @@
 #define   SDHCI_CTRL_ADMA1	0x08
 #define   SDHCI_CTRL_ADMA32	0x10
 #define   SDHCI_CTRL_ADMA64	0x18
+#define  SDHCI_CTRL_8BITBUS	0x20
 
 #define SDHCI_POWER_CONTROL	0x29
 #define  SDHCI_POWER_ON		0x01