hwmon: (ina2xx) Add device tree support to pass the shunt resistor

Adding another way that is device tree to pass the shunt resistor
value to driver except for platform data.

Signed-off-by: Tang Yuantian <Yuantian.Tang@freescale.com>
[Guenter Roeck: Added missing of.h include]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/i2c/ina2xx.txt b/Documentation/devicetree/bindings/i2c/ina2xx.txt
new file mode 100644
index 000000000000..a2ad85d7e747
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/ina2xx.txt
@@ -0,0 +1,22 @@
+ina2xx properties
+
+Required properties:
+- compatible: Must be one of the following:
+        - "ti,ina219" for ina219
+        - "ti,ina220" for ina220
+        - "ti,ina226" for ina226
+        - "ti,ina230" for ina230
+- reg: I2C address
+
+Optional properties:
+
+- shunt-resistor
+        Shunt resistor value in micro-Ohm
+
+Example:
+
+ina220@44 {
+        compatible = "ti,ina220";
+        reg = <0x44>;
+        shunt-resistor = <1000>;
+};