regulator: max14577: Add support for MAX77836 regulators

Add support for MAX77836 chipset and its additional two LDO regulators.
These LDO regulators are controlled by the PMIC block with additional
regmap (different I2C slave address).

The MAX77836 charger and safeout regulators are almost identical to
MAX14577. The registers layout is the same, except values for charger's
current. The patch adds simple mapping between device type and supported
current by the charger regulator.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/regulator/Kconfig

@@ -266,11 +266,12 @@ config REGULATOR_LP8788
 	  This driver supports LP8788 voltage regulator chip.
 
 config REGULATOR_MAX14577
-	tristate "Maxim 14577 regulator"
+	tristate "Maxim 14577/77836 regulator"
 	depends on MFD_MAX14577
 	help
-	  This driver controls a Maxim 14577 regulator via I2C bus.
-	  The regulators include safeout LDO and current regulator 'CHARGER'.
+	  This driver controls a Maxim MAX14577/77836 regulator via I2C bus.
+	  The MAX14577 regulators include safeout LDO and charger current
+	  regulator. The MAX77836 has two additional LDOs.
 
 config REGULATOR_MAX1586
 	tristate "Maxim 1586/1587 voltage regulator"

include/linux/mfd/max14577-private.h

@@ -261,9 +261,21 @@ enum max14577_charger_reg {
 #define MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP	 50000
 #define MAX14577_REGULATOR_CURRENT_LIMIT_MAX		950000
 
+/* MAX77836 regulator current limits (as in CHGCTRL4 register), uA */
+#define MAX77836_REGULATOR_CURRENT_LIMIT_MIN		 45000
+#define MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_START	100000
+#define MAX77836_REGULATOR_CURRENT_LIMIT_HIGH_STEP	 25000
+#define MAX77836_REGULATOR_CURRENT_LIMIT_MAX		475000
+
 /* MAX14577 regulator SFOUT LDO voltage, fixed, uV */
 #define MAX14577_REGULATOR_SAFEOUT_VOLTAGE		4900000
 
+/* MAX77836 regulator LDOx voltage, uV */
+#define MAX77836_REGULATOR_LDO_VOLTAGE_MIN		800000
+#define MAX77836_REGULATOR_LDO_VOLTAGE_MAX		3950000
+#define MAX77836_REGULATOR_LDO_VOLTAGE_STEP		50000
+#define MAX77836_REGULATOR_LDO_VOLTAGE_STEPS_NUM	64
+
 /* Slave addr = 0x46: PMIC */
 enum max77836_pmic_reg {
 	MAX77836_PMIC_REG_PMIC_ID		= 0x20,
@@ -298,6 +310,26 @@ enum max77836_pmic_reg {
 #define MAX77836_TOPSYS_INT_T120C_MASK		BIT(MAX77836_TOPSYS_INT_T120C_SHIFT)
 #define MAX77836_TOPSYS_INT_T140C_MASK		BIT(MAX77836_TOPSYS_INT_T140C_SHIFT)
 
+/* LDO1/LDO2 CONFIG1 register */
+#define MAX77836_CNFG1_LDO_PWRMD_SHIFT		6
+#define MAX77836_CNFG1_LDO_TV_SHIFT		0
+#define MAX77836_CNFG1_LDO_PWRMD_MASK		(0x3 << MAX77836_CNFG1_LDO_PWRMD_SHIFT)
+#define MAX77836_CNFG1_LDO_TV_MASK		(0x3f << MAX77836_CNFG1_LDO_TV_SHIFT)
+
+/* LDO1/LDO2 CONFIG2 register */
+#define MAX77836_CNFG2_LDO_OVCLMPEN_SHIFT	7
+#define MAX77836_CNFG2_LDO_ALPMEN_SHIFT		6
+#define MAX77836_CNFG2_LDO_COMP_SHIFT		4
+#define MAX77836_CNFG2_LDO_POK_SHIFT		3
+#define MAX77836_CNFG2_LDO_ADE_SHIFT		1
+#define MAX77836_CNFG2_LDO_SS_SHIFT		0
+#define MAX77836_CNFG2_LDO_OVCLMPEN_MASK	BIT(MAX77836_CNFG2_LDO_OVCLMPEN_SHIFT)
+#define MAX77836_CNFG2_LDO_ALPMEN_MASK		BIT(MAX77836_CNFG2_LDO_ALPMEN_SHIFT)
+#define MAX77836_CNFG2_LDO_COMP_MASK		(0x3 << MAX77836_CNFG2_LDO_COMP_SHIFT)
+#define MAX77836_CNFG2_LDO_POK_MASK		BIT(MAX77836_CNFG2_LDO_POK_SHIFT)
+#define MAX77836_CNFG2_LDO_ADE_MASK		BIT(MAX77836_CNFG2_LDO_ADE_SHIFT)
+#define MAX77836_CNFG2_LDO_SS_MASK		BIT(MAX77836_CNFG2_LDO_SS_SHIFT)
+
 /* Slave addr = 0x6C: Fuel-Gauge/Battery */
 enum max77836_fg_reg {
 	MAX77836_FG_REG_VCELL_MSB	= 0x02,

include/linux/mfd/max14577.h

@@ -35,7 +35,17 @@ enum max14577_regulators {
 	MAX14577_SAFEOUT = 0,
 	MAX14577_CHARGER,
 
-	MAX14577_REG_MAX,
+	MAX14577_REGULATOR_NUM,
+};
+
+/* MAX77836 regulator IDs */
+enum max77836_regulators {
+	MAX77836_SAFEOUT = 0,
+	MAX77836_CHARGER,
+	MAX77836_LDO1,
+	MAX77836_LDO2,
+
+	MAX77836_REGULATOR_NUM,
 };
 
 struct max14577_regulator_platform_data {