Qualcomm MSM GPIO-KEY device tree

1、add gpio-keys.c to build 
2、add gpio-keys device in your main dtsi like that: 
&soc { 
gpio_keys { 
compatible = "gpio-keys"; 
input-name = "gpio-keys"; 
pinctrl-names = "tlmm_gpio_key_active","tlmm_gpio_key_suspend"; 
pinctrl-0 = <&gpio_key_active>; 
pinctrl-1 = <&gpio_key_suspend>; 


vol_up { 
label = "volume_up";//key label name 
gpios = <&msm_gpio 107 0x1>;//gpio num 
linux,input-type = <1>;//don't need modify that 
linux,code = <115>;//the key value that you want to use 
gpio-key,wakeup;//could wakeup system 
debounce-interval = <15>;//the delay time for debounce 
}; 
camera_focus { 
label = "camera_focus"; 
gpios = <&msm_gpio 108 0x1>; 
linux,input-type = <1>; 
linux,code = <0x210>; 
gpio-key,wakeup; 
debounce-interval = <15>; 
}; 


}; 
}; 
3、add pinctrl in pinctrl.dtsi 
tlmm_gpio_key { 
qcom,pins = <&gp 107>, <&gp 108>; 
qcom,pin-func = <0>; 
qcom,num-grp-pins = <2>; 
label = "tlmm_gpio_key"; 
gpio_key_active: gpio_key_active { 
drive-strength = <2>; 
bias-pull-up; 
}; 
gpio_key_suspend: gpio_key_suspend { 
drive-strength = <2>; 
bias-pull-up; 
}; 
}; 
4、than check gpio-keys node. 
/sys/devices/soc.0/gpio_keys.* 
cat key 
and getevent to look the event.