power_supply: Add support for bq24735 charger

Adds support for the bq24735 charger chipset. The bq24735 is a
high-efficiency, synchronous battery charger.

It allows control of the charging current, input current, and the charger
voltage DAC's through SMBus.

Signed-off-by: Darbha Sriharsha <dsriharsha@nvidia.com>
Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Thanks-to: Stephen Warren <swarren@wwwdotorg.org>
Thanks-to: Thierry Reding <thierry.reding@gmail.com>
Thanks-to: Manish Badarkhe <badarkhe.manish@gmail.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

Documentation/devicetree/bindings/power_supply/ti,bq24735.txt

@@ -0,0 +1,32 @@
+TI BQ24735 Charge Controller
+~~~~~~~~~~
+
+Required properties :
+ - compatible : "ti,bq24735"
+
+Optional properties :
+ - interrupts : Specify the interrupt to be used to trigger when the AC
+   adapter is either plugged in or removed.
+ - ti,ac-detect-gpios : This GPIO is optionally used to read the AC adapter
+   presence. This is a Host GPIO that is configured as an input and
+   connected to the bq24735.
+ - ti,charge-current : Used to control and set the charging current. This value
+   must be between 128mA and 8.128A with a 64mA step resolution. The POR value
+   is 0x0000h. This number is in mA (e.g. 8192), see spec for more information
+   about the ChargeCurrent (0x14h) register.
+ - ti,charge-voltage : Used to control and set the charging voltage. This value
+   must be between 1.024V and 19.2V with a 16mV step resolution. The POR value
+   is 0x0000h. This number is in mV (e.g. 19200), see spec for more information
+   about the ChargeVoltage (0x15h) register.
+ - ti,input-current : Used to control and set the charger input current. This
+   value must be between 128mA and 8.064A with a 128mA step resolution. The
+   POR value is 0x1000h. This number is in mA (e.g. 8064), see the spec for
+   more information about the InputCurrent (0x3fh) register.
+
+Example:
+
+	bq24735@9 {
+		compatible = "ti,bq24735";
+		reg = <0x9>;
+		ti,ac-detect-gpios = <&gpio 72 0x1>;
+	}

drivers/power/Kconfig

@@ -346,6 +346,12 @@ config CHARGER_BQ24190
 	help
 	  Say Y to enable support for the TI BQ24190 battery charger.
 
+config CHARGER_BQ24735
+	tristate "TI BQ24735 battery charger support"
+	depends on I2C && GPIOLIB
+	help
+	  Say Y to enable support for the TI BQ24735 battery charger.
+
 config CHARGER_SMB347
 	tristate "Summit Microelectronics SMB347 Battery Charger"
 	depends on I2C

drivers/power/Makefile

@@ -52,6 +52,7 @@ obj-$(CONFIG_CHARGER_MAX8997)	+= max8997_charger.o
 obj-$(CONFIG_CHARGER_MAX8998)	+= max8998_charger.o
 obj-$(CONFIG_CHARGER_BQ2415X)	+= bq2415x_charger.o
 obj-$(CONFIG_CHARGER_BQ24190)	+= bq24190_charger.o
+obj-$(CONFIG_CHARGER_BQ24735)	+= bq24735-charger.o
 obj-$(CONFIG_POWER_AVS)		+= avs/
 obj-$(CONFIG_CHARGER_SMB347)	+= smb347-charger.o
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o