ARM: dts: add support for GPIO buttons for exynos4412-odroid

This patch adds support for simple GPIO-based button availabled on
Exynos4 based Odroid boards. All supported boards have POWER button,
which has been defined in exynos4412-odroid-common.dtsi. X/X2 boards
also have additional user-configurable button which has been mapped to
KEY_HOME. All defined keys have been marked as possible wakeup source.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos4412-odroid-common.dtsi

@@ -7,6 +7,7 @@
  * published by the Free Software Foundation.
 */
 
+#include <dt-bindings/input/input.h>
 #include "exynos4412.dtsi"
 
 / {
@@ -15,6 +16,22 @@ firmware@0204F000 {
 		reg = <0x0204F000 0x1000>;
 	};
 
+	gpio_keys {
+		compatible = "gpio-keys";
+		pinctrl-names = "default";
+		pinctrl-0 = <&gpio_power_key>;
+
+		power_key {
+			interrupt-parent = <&gpx1>;
+			interrupts = <3 0>;
+			gpios = <&gpx1 3 1>;
+			linux,code = <KEY_POWER>;
+			label = "power key";
+			debounce-interval = <10>;
+			gpio-key,wakeup;
+		};
+	};
+
 	mmc@12550000 {
 		pinctrl-0 = <&sd4_clk &sd4_cmd &sd4_bus4 &sd4_bus8>;
 		pinctrl-names = "default";
@@ -316,3 +333,10 @@ ehci: ehci@12580000 {
 		status = "okay";
 	};
 };
+
+&pinctrl_1 {
+	gpio_power_key: power_key {
+		samsung,pins = "gpx1-3";
+		samsung,pin-pud = <0>;
+	};
+};

arch/arm/boot/dts/exynos4412-odroidx.dts

@@ -46,6 +46,20 @@ serial@13830000 {
 		status = "okay";
 	};
 
+	gpio_keys {
+		pinctrl-0 = <&gpio_power_key &gpio_home_key>;
+
+		home_key {
+			interrupt-parent = <&gpx2>;
+			interrupts = <2 0>;
+			gpios = <&gpx2 2 0>;
+			linux,code = <KEY_HOME>;
+			label = "home key";
+			debounce-interval = <10>;
+			gpio-key,wakeup;
+		};
+	};
+
 	regulator_p3v3 {
 		compatible = "regulator-fixed";
 		regulator-name = "p3v3_en";
@@ -62,3 +76,10 @@ port@1 {
 		status = "okay";
 	};
 };
+
+&pinctrl_1 {
+	gpio_home_key: home_key {
+		samsung,pins = "gpx2-2";
+		samsung,pin-pud = <0>;
+	};
+};