一、驱动配置
Device Drivers --->Input device support --->Keyboards --->[*]ADC Ladder Buttons[*]GPIO Buttons
两种按键，一种是ADC按键，一个ADC引脚即可实现多按键检测
另外一种就是GPIO按键，一个引脚控制一个按键，还有按键矩阵，8个gpio可以监测16个按键（4*4）
二、设备树配置
1.ADC按键设备树
user_adc_keys: user-adc-keys {compatible = "adc-keys";io-channels = <&saradc 3>;io-channel-names = "buttons";keyup-threshold-microvolt = <1800000>;poll-interval = <100>;/* SW2 */vol-up-key {label = "volume up";linux,code = <KEY_VOLUMEUP>;press-threshold-microvolt = <410000>;};/* SW3 */vol-down-key {label = "volume down";linux,code = <KEY_VOLUMEDOWN>;press-threshold-microvolt = <870000>;};
};
2.ADC按键测试
3.GPIO按键设备树
这是放在根节点下的
keys:keys {compatible = "gpio-keys";pinctrl-names = "default";pinctrl-0 = <&button_pins>;autorepeat;key_down:key_down {label = "KEY_DOWN";linux,code = <KEY_DOWN>;gpios = <&gpio0 RK_PC1 GPIO_ACTIVE_LOW>;debounce-interval = <100>;};key_enter:key_enter {label = "KEY_ENTER";linux,code = <KEY_ENTER>;gpios = <&gpio0 RK_PC0 GPIO_ACTIVE_LOW>;debounce-interval = <100>;};key_up:key_up {label = "KEY_UP";linux,code = <KEY_UP>;gpios = <&gpio0 RK_PB6 GPIO_ACTIVE_LOW>;debounce-interval = <100>;};};
pinctrl设置引脚功能和内部上拉
&pinctrl {gpio-keys {button_pins: button-pins {rockchip,pins = <0 RK_PC1 RK_FUNC_GPIO &pcfg_pull_up0 RK_PC0 RK_FUNC_GPIO &pcfg_pull_up0 RK_PB6 RK_FUNC_GPIO &pcfg_pull_up>;};};};
4.GPIO按键测试
三、踩坑经过
首先是引脚一定要对
其次原理图排针引脚名称与CPU上引脚名称不一致导致按键键值错位
实际的引脚
