树莓派-键盘篇
1 keys驱动
新增文件：arch\arm\boot\dts\overlays\example-keys-overlay.dts
/dts-v1/;
/plugin/;
/ {
compatible = "brcm,bcm2835";
fragment@0 {
target = <&gpio>;
__overlay__ {
keypad_pins: keypad_pins {
brcm,pins = <17 22 23 27>;
brcm,function = <0>; /* in */
brcm,pull = <2>; /* up */
};
};
};
/*
* Values for input event code is found under the
* 'Keys and buttons' heading in include/uapi/linux/input.h
*/
fragment@1 {
target-path = "/soc";
__overlay__ {
keypad: keypad {
compatible = "gpio-keys";
#address-cells = <1>;
#size-cells = <0>;
pinctrl-names = "default";
pinctrl-0 = <&keypad_pins>;
status = "okay";
autorepeat;
button@17 {
label = "GPIO KEY_UP";
linux,code = <103>;
gpios = <&gpio 17 0>;
};
button@22 {
label = "GPIO KEY_DOWN";
linux,code = <108>;
gpios = <&gpio 22 0>;
};
button@27 {
label = "GPIO KEY_LEFT";
linux,code = <105>;
gpios = <&gpio 27 0>;
};
button@23 {
label = "GPIO KEY_RIGHT";
linux,code = <106>;
gpios = <&gpio 23 0>;
};
};
};
};
__overrides__ {
keypad = <&keypad>,"status";
};
};
linux\arch\arm\boot\dts\overlays\Makefile
dtbo-$(RPI_DT_OVERLAYS) += example-keys.dtbo
2 KERNEL编译
export PATH=$PATH:/home/thornton/work/pi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=/home/thornton/work/pi/firmware modules_install
3 KERNEL更新
将RPI T卡插在LINUX系统下，会弹出两个盘，一个是KERENL盘和一个BOOT盘
将firmware/lib拷到KERNEL盘，其他拷到BOOT盘
4 启动驱动
dtoverlay=example-keys
使能gpio-keys.ko
5 map key to system
Edit file ~/.config/openbox/lxde-rc.xml
Insert this code in the keyboard section:
CODE: SELECT ALL