power: supply: add CellWise cw2015 fuel gauge driver

This patch adds a driver for the CellWise cw2015 fuel gauge.

The CellWise cw2015 is a shuntless, single-cell Li-Ion fuel gauge used
in the pine64 Pinebook Pro laptop and some Raspberry Pi UPS HATs.

Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

MAINTAINERS

@@ -3932,6 +3932,12 @@ F:	arch/powerpc/include/uapi/asm/spu*.h
 F:	arch/powerpc/oprofile/*cell*
 F:	arch/powerpc/platforms/cell/
 
+CELLWISE CW2015 BATTERY DRIVER
+M:	Tobias Schrammm <t.schramm@manjaro.org>
+S:	Maintained
+F:	Documentation/devicetree/bindings/power/supply/cw2015_battery.yaml
+F:	drivers/power/supply/cw2015_battery.c
+
 CEPH COMMON CODE (LIBCEPH)
 M:	Ilya Dryomov <idryomov@gmail.com>
 M:	Jeff Layton <jlayton@kernel.org>

drivers/power/supply/Kconfig

@@ -116,6 +116,17 @@ config BATTERY_CPCAP
 	  Say Y here to enable support for battery on Motorola
 	  phones and tablets such as droid 4.
 
+config BATTERY_CW2015
+	tristate "CW2015 Battery driver"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Say Y here to enable support for the cellwise cw2015
+	  battery fuel gauge (used in the Pinebook Pro & others)
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cw2015_battery.
+
 config BATTERY_DS2760
 	tristate "DS2760 battery driver (HP iPAQ & others)"
 	depends on W1

drivers/power/supply/Makefile

@@ -24,6 +24,7 @@ obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
 obj-$(CONFIG_BATTERY_AXP20X)	+= axp20x_battery.o
 obj-$(CONFIG_CHARGER_AXP20X)	+= axp20x_ac_power.o
 obj-$(CONFIG_BATTERY_CPCAP)	+= cpcap-battery.o
+obj-$(CONFIG_BATTERY_CW2015)	+= cw2015_battery.o
 obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
 obj-$(CONFIG_BATTERY_DS2780)	+= ds2780_battery.o
 obj-$(CONFIG_BATTERY_DS2781)	+= ds2781_battery.o