在rk3399跑Android7.1.2系统上怎样去添加HOME和返回键呢

这两天在研究rk3399跑Android7.1.2系统，自己添加HOME和返回键。

研究linux或者Android驱动移植一直秉承自下向上的研究

首先硬件，Android7.1.2HOME和返回键已经可以脱离实体硬件，用虚拟按键充当了。

设备树目录 Android_Src_Path/kernel/arch/arm64/boot/dts/rockchip/

rk3399-android.dtsi中定义了HOME,BACK等按键。可以看到power键是实体按键，HOME，返回，MENU键没有实体按键。

/*rk3399-android.dtsi文件部分内容*/

rk_key: rockchip-key {

compatible = "rockchip,key";

status = "okay";

io-channels = ;

vol-up-key {

linux,code = <113>;

label = "volume up";

rockchip,adc_value = <1>;

};

vol-down-key {

linux,code = <114>;

label = "volume down";

rockchip,adc_value = <170>;

};

power-key {

gpios = ;

linux,code = <116>;

label = "power";

gpio-key,wakeup;

};

menu-key {

linux,code = <59>;

label = "menu";

rockchip,adc_value = <746>;

};

home-key {

linux,code = <102>;

label = "home";

rockchip,adc_value = <355>;

};

back-key {

linux,code = <158>;

label = "back";

rockchip,adc_value = <560>;

};

camera-key {

linux,code = <212>;

label = "camera";

rockchip,adc_value = <450>;

};

};