hwmon: (ina2xx) Add ina231 compatible string

Add support for "ina231" as compatible string, and update
Documentation and Kconfig accordingly.

Tested with the Exynos5422-based odroid-xu3 board which has on-board
INA231 sensors.
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/ina2xx

@@ -26,6 +26,12 @@ Supported chips:
     Datasheet: Publicly available at the Texas Instruments website
                http://www.ti.com/
 
+  * Texas Instruments INA231
+    Prefix: 'ina231'
+    Addresses: I2C 0x40 - 0x4f
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
 Author: Lothar Felten <l-felten@ti.com>
 
 Description
@@ -41,8 +47,9 @@ interface. The INA220 monitors both shunt drop and supply voltage.
 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 INA230 is a high or low side current shunt and power monitor with an I2C
-interface. The INA230 monitors both a shunt voltage drop and bus supply voltage.
+INA230 and INA231 are high or low side current shunt and power monitors
+with an I2C interface. The chips monitor both a shunt voltage drop and
+bus supply voltage.
 
 The shunt value in micro-ohms can be set via platform data or device tree at
 compile-time or via the shunt_resistor attribute in sysfs at run-time. Please

drivers/hwmon/Kconfig

@@ -1430,8 +1430,8 @@ config SENSORS_INA2XX
 	tristate "Texas Instruments INA219 and compatibles"
 	depends on I2C
 	help
-	  If you say yes here you get support for INA219, INA220, INA226, and
-	  INA230 power monitor chips.
+	  If you say yes here you get support for INA219, INA220, INA226,
+	  INA230, and INA231 power monitor chips.
 
 	  The INA2xx driver is configured for the default configuration of
 	  the part as described in the datasheet.

drivers/hwmon/ina2xx.c

@@ -538,6 +538,7 @@ static const struct i2c_device_id ina2xx_id[] = {
 	{ "ina220", ina219 },
 	{ "ina226", ina226 },
 	{ "ina230", ina226 },
+	{ "ina231", ina226 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, ina2xx_id);