1. 关注属性gpio-hog
GPIO hogging is a mechanism providing automatic GPIO request and configuration as part of the gpio-controller's driver probe function.(gpio-hog是一种提供自动gpio资源申请并且配置为gpio控制器驱动探测函数的一部分的机制)
2. 举例
pca9554:pca9554@20 {
compatible = "nxp,pca9554";
compatible = "nxp,pca9554";
reg=<0x20>;
gpio-controller;
#gpio-cells=<2>;
interrupt-controller;
#interrupt-cells = <2>;
interrupt-parent = <&gpio3>;
interrupts = <28 IRQ_TYPE_NONE>;
P00 {
P00 {
gpio-hog;
gpios = <0 GPIO_ACTIVE_LOW>;
output-high;
line-name = "led_normal";
output-high;
line-name = "led_normal";
}
}
3. 如何引用pca9554节点?
displayport {
dp.aux_sw_oe = <&pca9554 4 GPIO_ACTIVE_HIGH>
dp.sbu_sw_sel = <&pca9554 1 GPIO_ACTIVE_HIGH>
};