regulator: s5m8767: Use GPIO for controlling Buck9/eMMC

Add support for GPIO control (enable/disable) over Buck9. The Buck9
Converter is used as a supply for eMMC Host Controller.

BUCK9EN GPIO of S5M8767 chip may be used by application processor to
enable or disable the Buck9. This has two benefits:
 - It is faster than toggling it over I2C bus.
 - It allows disabling the regulator during suspend to RAM; The AP will
   enable it during resume; Without the patch the regulator supplying
   eMMC must be defined as fixed-regulator.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 9 insertions, 1 deletions

diff --git a/include/linux/mfd/samsung/core.h b/include/linux/mfd/samsung/core.h
index 41c9bde410c5..55510444b9fd 100644
--- a/include/linux/mfd/samsung/core.h
+++ b/include/linux/mfd/samsung/core.h
@@ -119,7 +119,8 @@ struct sec_platform_data {
 struct sec_regulator_data {
         int                             id;
         struct regulator_init_data      *initdata;
-        struct device_node *reg_node;
+        struct device_node              *reg_node;
+        int                             ext_control_gpio;
 };
 
 /*
diff --git a/include/linux/mfd/samsung/s5m8767.h b/include/linux/mfd/samsung/s5m8767.h
index 2ab0b0f03641..243b58fec33d 100644
--- a/include/linux/mfd/samsung/s5m8767.h
+++ b/include/linux/mfd/samsung/s5m8767.h
@@ -183,10 +183,17 @@ enum s5m8767_regulators {
         S5M8767_REG_MAX,
 };
 
+/* LDO_EN/BUCK_EN field in registers */
 #define S5M8767_ENCTRL_SHIFT            6
 #define S5M8767_ENCTRL_MASK             (0x3 << S5M8767_ENCTRL_SHIFT)
 
 /*
+ * LDO_EN/BUCK_EN register value for controlling this Buck or LDO
+ * by GPIO (PWREN, BUCKEN).
+ */
+#define S5M8767_ENCTRL_USE_GPIO         0x1
+
+/*
  * Values for BUCK_RAMP field in DVS_RAMP register, matching raw values
  * in mV/us.
  */