ODROID-N2: overlay: add shutdown via GPIO

arch/arm64/boot/dts/amlogic/overlays/odroidn2/Makefile

@@ -13,7 +13,8 @@ dtbo-y += \
 	uart0.dtbo \
 	uart1.dtbo \
 	w1-gpio_p15.dtbo \
-	w1-gpio_p22.dtbo
+	w1-gpio_p22.dtbo \
+	gpio-poweroff.dtbo
 
 targets += $(dtbo-y)
 always-y := $(dtbo-y)

arch/arm64/boot/dts/amlogic/overlays/odroidn2/gpio-poweroff.dtso

@@ -0,0 +1,45 @@
+/dts-v1/;
+/plugin/;
+
+#include <dt-bindings/gpio/meson-g12a-gpio.h>
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+	fragment@0 {
+		target = <&periphs_pinctrl>;
+
+		__overlay__ {
+			shutdown_gpio_pins: shutdown-gpio-state {
+				mux {
+					groups = "GPIOX_3";
+					function = "shutdown";
+					output-disable;
+					bias-pull-up;
+					drive-strength-microamp = <4000>;
+				};
+			};
+		};
+	};
+
+	fragment@1 {
+		target-path = "/soc";
+
+		__overlay__ {
+			shutdown_gpio: shutdown_gpio@3 {
+				compatible = "gpio-keys-polled";
+				poll-interval = <10>;
+				pinctrl-names = "default";
+				pinctrl-0 = <&shutdown_gpio_pins>;
+
+				status = "okay";
+
+				shutdown {
+					label = "shutdown";
+					linux,code = <116>;
+					gpios = <&gpio GPIOX_3 GPIO_ACTIVE_LOW>;
+					debounce-interval = <100>;
+				};
+			};
+		};
+	};
+};