hwmon: (ads7828) Accept optional parameters from device tree

Adding the ability for the ads7828 and ads7830 to use device tree to
get optional parameters instead of using platform devices. This allows
people using custom boards to also use the ads7828 in a non-default manner.

Signed-off-by: Sam Povilus <kernel.development@povil.us>
[groeck: Fixed whitespace errors in ads7828.txt]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 25 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/hwmon/ads7828.txt b/Documentation/devicetree/bindings/hwmon/ads7828.txt
new file mode 100644
index 000000000000..fe0cc4ad7ea9
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ads7828.txt
@@ -0,0 +1,25 @@
+ads7828 properties
+
+Required properties:
+- compatible: Should be one of
+	       ti,ads7828
+	       ti,ads7830
+- reg: I2C address
+
+Optional properties:
+
+- ti,differential-input
+  Set to use the device in differential mode.
+- vref-supply
+  The external reference on the device is set to this regulators output. If it
+  does not exists the internal reference will be used and output by the ads78xx
+  on the "external vref" pin.
+
+  Example ADS7828 node:
+
+  ads7828: ads@48 {
+	   comatible = "ti,ads7828";
+	   reg = <0x48>;
+	   vref-supply = <&vref>;
+	   ti,differential-input;
+  };