[PATCH] lm87: Allow LM87_REG_CHANNEL_MODE to be set via DT

[Jason Gunthorpe <jgunthorpe@obsidianresearch.com>]

This compliments the existing scheme that lets it be set via
platform_data.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
---
 Documentation/devicetree/bindings/hwmon/lm87.txt | 27 ++++++++++++++++++++++++
 drivers/hwmon/lm87.c                             |  8 ++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/hwmon/lm87.txt

diff --git a/Documentation/devicetree/bindings/hwmon/lm87.txt b/Documentation/devicetree/bindings/hwmon/lm87.txt
new file mode 100644
index 00000000000000..4ea2646ce8d2f0
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/lm87.txt
@@ -0,0 +1,27 @@
+* LM87 I2C Temperature and Fan sensor
+
+Required properties:
+- compatible: should contain one of
+		* "national,lm87"
+		* "ti,lm87"
+
+Optional properties:
+- channel-mode: Write the specified value to register 0x16. If not specified
+                the driver will read the value from the chip at startup.
+
+		The value controls how the driver operates certain multi-use
+		pins, eg bit 2 will select between temp_input3 or
+		in0&in5 operation.
+
+See Documentation/devicetree/bindings/i2c/i2c.txt for more required and
+optional properties.
+
+Example:
+
+i2c_master {
+	temperature-sensor@0 {
+		compatible = "ti,lm87";
+		channel-mode = <0x4>;
+		reg = <0>;
+	};
+};
diff --git a/drivers/hwmon/lm87.c b/drivers/hwmon/lm87.c
index 81cb898245a107..ccc0c913b4534e 100644
--- a/drivers/hwmon/lm87.c
+++ b/drivers/hwmon/lm87.c
@@ -853,9 +853,15 @@ static void lm87_restore_config(void *arg)
 static int lm87_init_client(struct i2c_client *client)
 {
 	struct lm87_data *data = i2c_get_clientdata(client);
+	u32 channel;
 	int rc;
 
-	if (dev_get_platdata(&client->dev)) {
+	if (client->dev.of_node &&
+	    !of_property_read_u32(client->dev.of_node, "channel-mode",
+				  &channel)) {
+		data->channel = channel;
+		lm87_write_value(client, LM87_REG_CHANNEL_MODE, data->channel);
+	} else if (dev_get_platdata(&client->dev)) {
 		data->channel = *(u8 *)dev_get_platdata(&client->dev);
 		lm87_write_value(client,
 				 LM87_REG_CHANNEL_MODE, data->channel);
-- 
2.7.4