hwmon: (ltc2990) add devicetree binding

Add a devicetree binding for the ltc2990 hwmon driver.

Signed-off-by: Tom Levens <tom.levens@cern.ch>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/devicetree/bindings/hwmon/ltc2990.txt b/Documentation/devicetree/bindings/hwmon/ltc2990.txt
new file mode 100644 (file)
index 0000000..f92f540
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ltc2990.txt
@@ -0,0 +1,36 @@
+ltc2990: Linear Technology LTC2990 power monitor
+
+Required properties:
+- compatible: Must be "lltc,ltc2990"
+- reg: I2C slave address
+- lltc,meas-mode:
+       An array of two integers for configuring the chip measurement mode.
+
+       The first integer defines the bits 2..0 in the control register. In all
+       cases the internal temperature and supply voltage are measured. In
+       addition the following input measurements are enabled per mode:
+
+               0: V1, V2, TR2
+               1: V1-V2, TR2
+               2: V1-V2, V3, V4
+               3: TR1, V3, V4
+               4: TR1, V3-V4
+               5: TR1, TR2
+               6: V1-V2, V3-V4
+               7: V1, V2, V3, V4
+
+       The second integer defines the bits 4..3 in the control register. This
+       allows a subset of the measurements to be enabled:
+
+               0: Internal temperature and supply voltage only
+               1: TR1, V1 or V1-V2 only per mode
+               2: TR2, V3 or V3-V4 only per mode
+               3: All measurements per mode
+
+Example:
+
+ltc2990@4c {
+       compatible = "lltc,ltc2990";
+       reg = <0x4c>;
+       lltc,meas-mode = <7 3>; /* V1, V2, V3, V4 */
+};