regulator: as3722: detect SD0 low-voltage mode

SD0 may operate in low-voltage mode, with a minimum of 0.41V
and a maximum of 1.5V.  This is indicated by bit 4 of FUSE7.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Vince Hsu <vinceh@nvidia.com>
broonie.e6264@m.evernote.com
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/linux/mfd/as3722.h b/include/linux/mfd/as3722.h
index 16bf8a0..bb9616d 100644
--- a/include/linux/mfd/as3722.h
+++ b/include/linux/mfd/as3722.h
@@ -151,6 +151,7 @@
 #define AS3722_ASIC_ID1_REG				0x90
 #define AS3722_ASIC_ID2_REG				0x91
 #define AS3722_LOCK_REG					0x9E
+#define AS3722_FUSE7_REG				0xA7
 #define AS3722_MAX_REGISTER				0xF4
 
 #define AS3722_SD0_EXT_ENABLE_MASK			0x03
@@ -224,6 +225,7 @@
 #define AS3722_SD_VSEL_MASK				0x7F
 #define AS3722_SD0_VSEL_MIN				0x01
 #define AS3722_SD0_VSEL_MAX				0x5A
+#define AS3722_SD0_VSEL_LOW_VOL_MAX			0x6E
 #define AS3722_SD2_VSEL_MIN				0x01
 #define AS3722_SD2_VSEL_MAX				0x7F
 
@@ -341,6 +343,8 @@
 #define AS3722_EXT_CONTROL_ENABLE2			0x2
 #define AS3722_EXT_CONTROL_ENABLE3			0x3
 
+#define AS3722_FUSE7_SD0_LOW_VOLTAGE			BIT(4)
+
 /* Interrupt IDs */
 enum as3722_irq {
 	AS3722_IRQ_LID,