power: supply: max77976: add Maxim MAX77976 charger driver

Add support for the MAX77976 3.5/5.5A 1-Cell Li+ Battery Charger.

This is a simple implementation enough to be used as a simple battery
charger without OTG and boost.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

MAINTAINERS

@@ -11584,6 +11584,7 @@ MAXIM MAX77976 BATTERY CHARGER
 M:	Luca Ceresoli <luca@lucaceresoli.net>
 S:	Supported
 F:	Documentation/devicetree/bindings/power/supply/maxim,max77976.yaml
+F:	drivers/power/supply/max77976_charger.c
 
 MAXIM MUIC CHARGER DRIVERS FOR EXYNOS BASED BOARDS
 M:	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

drivers/power/supply/Kconfig

@@ -557,6 +557,18 @@ config CHARGER_MAX77693
 	help
 	  Say Y to enable support for the Maxim MAX77693 battery charger.
 
+config CHARGER_MAX77976
+	tristate "Maxim MAX77976 battery charger driver"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  The Maxim MAX77976 is a 19 Vin, 5.5A 1-Cell Li+ Battery Charger
+	  USB OTG support. It has an I2C interface for configuration.
+
+	  Say Y to enable support for the Maxim MAX77976 battery charger.
+	  This driver can also be built as a module. If so, the module will be
+	  called max77976_charger.
+
 config CHARGER_MAX8997
 	tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
 	depends on MFD_MAX8997 && REGULATOR_MAX8997

drivers/power/supply/Makefile

@@ -75,6 +75,7 @@ obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o
 obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o
 obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o
 obj-$(CONFIG_CHARGER_MAX77693)	+= max77693_charger.o
+obj-$(CONFIG_CHARGER_MAX77976)	+= max77976_charger.o
 obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
 obj-$(CONFIG_CHARGER_MP2629)	+= mp2629_charger.o