regulator: rt5120: Add PMIC regulator support

Add RT5120 PMIC regulator support.

It integrates 4 buck convertes, 1 LDO voltage regulator, 1 external
enable signal to control the external power source.
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/1655892104-10874-4-git-send-email-u0084500@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -1047,6 +1047,16 @@ config REGULATOR_RT5033
 	  RT5033 PMIC. The device supports multiple regulators like
 	  current source, LDO and Buck.
 
+config REGULATOR_RT5120
+	tristate "Richtek RT5120 PMIC Regulators"
+	depends on MFD_RT5120
+	help
+	  This adds support for voltage regulator in Richtek RT5120 PMIC.
+	  It integrates 4 channels buck controller, 1 channel LDO, 1 EXTEN
+	  to control external power source. Only BUCK1 is adjustable from
+	  600mV to 1395mV, per step 6.250mV. The others are all fixed voltage
+	  by external hardware circuit.
+
 config REGULATOR_RT5190A
 	tristate "Richtek RT5190A PMIC"
 	depends on I2C

drivers/regulator/Makefile

@@ -126,6 +126,7 @@ obj-$(CONFIG_REGULATOR_ROHM)	+= rohm-regulator.o
 obj-$(CONFIG_REGULATOR_RT4801)	+= rt4801-regulator.o
 obj-$(CONFIG_REGULATOR_RT4831)	+= rt4831-regulator.o
 obj-$(CONFIG_REGULATOR_RT5033)	+= rt5033-regulator.o
+obj-$(CONFIG_REGULATOR_RT5120)	+= rt5120-regulator.o
 obj-$(CONFIG_REGULATOR_RT5190A) += rt5190a-regulator.o
 obj-$(CONFIG_REGULATOR_RT5759)	+= rt5759-regulator.o
 obj-$(CONFIG_REGULATOR_RT6160)	+= rt6160-regulator.o