From 8502633ed831fb17441a348b14b95d88118551f4 Mon Sep 17 00:00:00 2001
From: Jianqun Xu <jay.xu@rock-chips.com>
Date: Mon, 27 Mar 2017 09:36:20 +0800
Subject: [PATCH] Input: add document for rockchip keys

Change-Id: I3f8f4522e6279e3f5faf3f293936c835ce8fc6b7
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
---
 .../bindings/input/rockchip-keys.txt          | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/rockchip-keys.txt

diff --git a/Documentation/devicetree/bindings/input/rockchip-keys.txt b/Documentation/devicetree/bindings/input/rockchip-keys.txt
new file mode 100644
index 000000000000..7b3fba3a6a67
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/rockchip-keys.txt
@@ -0,0 +1,69 @@
+ROCKCHIP ADC attached resistor ladder buttons
+------------------------------------
+
+Required properties:
+ - compatible: "rockchip,key"
+ - io-channels: Phandle to an ADC channel
+
+Each button (key) is represented as a sub-node of "rockchip,key":
+
+Required subnode-properties:
+	- label: Descriptive name of the key.
+	- linux,code: Keycode to emit.
+	- rockchip,adc_value:: Voltage ADC input when this key is pressed.
+
+Example:
+
+#include <dt-bindings/input/input.h>
+
+	rk_key: rockchip-key {
+		compatible = "rockchip,key";
+		status = "okay";
+
+		io-channels = <&saradc 1>;
+
+		vol-up-key {
+			linux,code = <115>;
+			label = "volume up";
+			rockchip,adc_value = <1>;
+		};
+
+		vol-down-key {
+			linux,code = <114>;
+			label = "volume down";
+			rockchip,adc_value = <170>;
+		};
+
+		power-key {
+			gpios = <&gpio0 5 GPIO_ACTIVE_LOW>;
+			linux,code = <116>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&pwrbtn>;
+			label = "power";
+			gpio-key,wakeup;
+		};
+
+		menu-key {
+			linux,code = <59>;
+			label = "menu";
+			rockchip,adc_value = <355>;
+		};
+
+		home-key {
+			linux,code = <102>;
+			label = "home";
+			rockchip,adc_value = <746>;
+		};
+
+		back-key {
+			linux,code = <158>;
+			label = "back";
+			rockchip,adc_value = <560>;
+		};
+
+		camera-key {
+			linux,code = <212>;
+			label = "camera";
+			rockchip,adc_value = <450>;
+		};
+	};
-- 
2.34.1