omap: TWL4030 Bump VMMC1 interface voltage from 3V to 3.15V

MMC interfaces are specified to be 3.3V compatible with an operating
voltage range of 3.1V to 3.5V for SD cards. This change affects
hardware using TWL4030 (TPS6595x) PMICs and should improve the
reliability when communicating with marginally-spec'd MMC devices.
3.15V is the highest possible level for this chip.  This patch
has been tested on a Gumstix Overo board.

Signed-off-by: Ash Charles <ash@gumstix.com>
Tested-by: Steve Sakoman <steve@sakoman.com>

drivers/power/twl4030.c

@@ -97,9 +97,9 @@ void twl4030_power_init(void)
 
 void twl4030_power_mmc_init(void)
 {
-	/* Set VMMC1 to 3 Volts */
+	/* Set VMMC1 to 3.15 Volts */
 	twl4030_pmrecv_vsel_cfg(TWL4030_PM_RECEIVER_VMMC1_DEDICATED,
-				TWL4030_PM_RECEIVER_VMMC1_VSEL_30,
+				TWL4030_PM_RECEIVER_VMMC1_VSEL_32,
 				TWL4030_PM_RECEIVER_VMMC1_DEV_GRP,
 				TWL4030_PM_RECEIVER_DEV_GRP_P1);
 }

include/twl4030.h

@@ -310,6 +310,7 @@
 #define TWL4030_PM_RECEIVER_VPLL2_VSEL_18		0x05
 #define TWL4030_PM_RECEIVER_VDAC_VSEL_18		0x03
 #define TWL4030_PM_RECEIVER_VMMC1_VSEL_30		0x02
+#define TWL4030_PM_RECEIVER_VMMC1_VSEL_32		0x03
 
 /* Device Selection in PM Receiver Module */
 #define TWL4030_PM_RECEIVER_DEV_GRP_P1			0x20