Android 10 添加一个新物理按键

Android 10 添加一个新物理按键
下面简单记录下如何添加一个新的物理按键

一、kernel修改
kernel/msm-4.19/include/dt-bindings/input/linux-event-codes.h中定义新按键：

#define KEY_RFKILL		247	/* Key that controls all radios */
#define KEY_MICMUTE		248	/* Mute / unmute the microphone */
#define KEY_NEW		        249    //添加新按键，映射给Android 上层的也是此值

/vendor/qcom/proprietary/devicetree-4.19/qcom/kona-xr.dtsi

&soc {
	gpio_keys {
		compatible = "gpio-keys";
		label = "gpio-keys";
		.........
          new {
			label = "new";
			gpios = <&pm8150_gpios 6 GPIO_ACTIVE_LOW>;
			linux,input-type = <1>;
			linux,code = <KEY_NEW>;
			gpio-key,wakeup;
			debounce-interval = <15>;
			linux,can-disable;
		};
	};
 ......
}

添加成功后操作此GPIO，在adb 串口可使用getevent命令，get到其映射到上层的值249的十六进制值 为f9

130|bengal:/ # getevent
/dev/input/event1: 0001 00f9 00000001
/dev/input/event1: 0000 0000 00000000
/dev/input/event1: 0001