From 3221372d75cd4e905aedbe7adb035f63446b76ef Mon Sep 17 00:00:00 2001
From: Tang Yuantian <yuantian.tang@freescale.com>
Date: Thu, 17 Oct 2013 10:51:39 +0800
Subject: 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>
Change-Id: I6596e57de7e9021a19d16e6060c3c78f83cc81c3
Reviewed-on: http://git.am.freescale.net:8181/4786
Reviewed-by: Hongtao Jia <hongtao.jia@freescale.com>
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Rivera Jose-B46482 <German.Rivera@freescale.com>

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..bd3b225 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -44,4 +44,6 @@ 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.
 
-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 Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings
+if device tree is used.
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 8e7158c..0ddfa16 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 @@ static int ina2xx_probe(struct i2c_client *client,
 	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 @@ static int ina2xx_probe(struct i2c_client *client,
 		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)
-- 
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