regulator: max77620: add regulator driver for max77620/max20024

MAXIM Semiconductor's PMIC, MAX77620 and MAX20024 have the
multiple DCDC and LDOs. This supplies the power to different
components of the system.
Also these rails has configuration for ramp time, flexible
power sequence, slew rate etc.

Add regulator driver to access these rails via regulator APIs.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mallikarjun Kasoju <mkasoju@nvidia.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -343,6 +343,15 @@ config REGULATOR_MAX1586
 	  regulator via I2C bus. The provided regulator is suitable
 	  for PXA27x chips to control VCC_CORE and VCC_USIM voltages.
 
+config REGULATOR_MAX77620
+	tristate "Maxim 77620/MAX20024 voltage regulator"
+	depends on MFD_MAX77620
+	help
+	  This driver controls Maxim MAX77620 voltage output regulator
+	  via I2C bus. The provided regulator is suitable for Tegra
+	  chip to control Step-Down DC-DC and LDOs. Say Y here to
+	  enable the regulator driver.
+
 config REGULATOR_MAX8649
 	tristate "Maxim 8649 voltage regulator"
 	depends on I2C

drivers/regulator/Makefile

@@ -46,6 +46,7 @@ obj-$(CONFIG_REGULATOR_LP8755) += lp8755.o
 obj-$(CONFIG_REGULATOR_LTC3589) += ltc3589.o
 obj-$(CONFIG_REGULATOR_MAX14577) += max14577.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
+obj-$(CONFIG_REGULATOR_MAX77620) += max77620-regulator.o
 obj-$(CONFIG_REGULATOR_MAX8649)	+= max8649.o
 obj-$(CONFIG_REGULATOR_MAX8660) += max8660.o
 obj-$(CONFIG_REGULATOR_MAX8907) += max8907-regulator.o