hwmon: INA219 and INA226 support

Add support for the Texas Instruments INA219 and INA226 power monitors.

Signed-off-by: Lothar Felten <l-felten@ti.com>
[guenter.roeck@ericsson.com: formatting cleanup; check for smbus word data;
 select PGA=8 for INA219]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

Documentation/hwmon/ina2xx

@@ -0,0 +1,29 @@
+Kernel driver ina2xx
+====================
+
+Supported chips:
+  * Texas Instruments INA219
+    Prefix: 'ina219'
+    Addresses: I2C 0x40 - 0x4f
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+  * Texas Instruments INA226
+    Prefix: 'ina226'
+    Addresses: I2C 0x40 - 0x4f
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+Author: Lothar Felten <l-felten@ti.com>
+
+Description
+-----------
+
+The INA219 is a high-side current shunt and power monitor with an I2C
+interface. The INA219 monitors both shunt drop and supply voltage, with
+programmable conversion times and filtering.
+
+The INA226 is a current shunt and power monitor with an I2C interface.
+The INA226 monitors both a shunt voltage drop and bus supply voltage.
+
+The shunt value in micro-ohms can be set via platform data.

drivers/hwmon/Kconfig

@@ -1102,6 +1102,19 @@ config SENSORS_AMC6821
 	  This driver can also be build as a module.  If so, the module
 	  will be called amc6821.
 
+config SENSORS_INA2XX
+	tristate "Texas Instruments INA219, INA226"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for INA219 and INA226 power
+	  monitor chips.
+
+	  The INA2xx driver is configured for the default configuration of
+	  the part as described in the datasheet.
+	  Default value for Rshunt is 10 mOhms.
+	  This driver can also be built as a module.  If so, the module
+	  will be called ina2xx.
+
 config SENSORS_THMC50
 	tristate "Texas Instruments THMC50 / Analog Devices ADM1022"
 	depends on I2C

drivers/hwmon/Makefile

@@ -62,6 +62,7 @@ obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
 obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
+obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
 obj-$(CONFIG_SENSORS_JC42)	+= jc42.o
 obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o