power: supply: rt9471: Add Richtek RT9471 charger driver

Add support for the RT9471 3A 1-Cell Li+ battery charger.

The RT9471 is a highly-integrated 3A switch mode battery charger with
low impedance power path to better optimize the charging efficiency.
Co-developed-by: Alina Yu <alina_yu@richtek.com>
Signed-off-by: Alina Yu <alina_yu@richtek.com>
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

drivers/power/supply/Kconfig

@@ -793,6 +793,22 @@ config CHARGER_RT9455
 	help
 	  Say Y to enable support for Richtek RT9455 battery charger.
 
+config CHARGER_RT9471
+	tristate "Richtek RT9471 battery charger driver"
+	depends on I2C && GPIOLIB && REGULATOR
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	select LINEAR_RANGES
+	help
+	  This adds support for Richtek RT9471 battery charger. RT9471 is
+	  highly-integrated switch mode battery charger which is system power
+	  patch manageable device for single cell Li-Ion and Li-polymer battery.
+	  It can support BC12 detection on DPDM, and current and voltage
+	  regulation on both charging and boost mode.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called rt9471.
+
 config CHARGER_CROS_USBPD
 	tristate "ChromeOS EC based USBPD charger"
 	depends on CROS_USBPD_NOTIFY

drivers/power/supply/Makefile

@@ -57,6 +57,7 @@ obj-$(CONFIG_BATTERY_MAX1721X)	+= max1721x_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
 obj-$(CONFIG_BATTERY_RT5033)	+= rt5033_battery.o
 obj-$(CONFIG_CHARGER_RT9455)	+= rt9455_charger.o
+obj-$(CONFIG_CHARGER_RT9471)	+= rt9471.o
 obj-$(CONFIG_BATTERY_S3C_ADC)	+= s3c_adc_battery.o
 obj-$(CONFIG_BATTERY_TWL4030_MADC)	+= twl4030_madc_battery.o
 obj-$(CONFIG_CHARGER_88PM860X)	+= 88pm860x_charger.o