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>
diff --git a/Documentation/devicetree/bindings/i2c/ina2xx.txt b/Documentation/devicetree/bindings/i2c/ina2xx.txt
new file mode 100644
index 0000000..a2ad85d
--- /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>;
+};
diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
index 03444f9..4223c2d 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -44,4 +44,6 @@
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.
-The shunt value in micro-ohms can be set via platform data.
+The shunt value in micro-ohms can be set via platform data or device tree.
+Please refer to the Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings
+if the device tree is used.
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 4958b2f..d917a2d 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -34,6 +34,7 @@
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
+#include <linux/of.h>
#include <linux/platform_data/ina2xx.h>
@@ -221,6 +222,7 @@
struct ina2xx_data *data;
struct ina2xx_platform_data *pdata;
int ret;
+ u32 val;
long shunt = 10000; /* default shunt value 10mOhms */
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
@@ -234,6 +236,9 @@
pdata =
(struct ina2xx_platform_data *)client->dev.platform_data;
shunt = pdata->shunt_uohms;
+ } else if (!of_property_read_u32(client->dev.of_node,
+ "shunt-resistor", &val)) {
+ shunt = val;
}
if (shunt <= 0)