linux内核如何为gpio 扩展芯片驱动添加设备节点?
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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"; reg=<0x20>; gpio-controller; #gpio-cells=<2>; interrupt-controller; #interrupt-cells = <2>; interrupt-parent = <&gpio3>; interrupts = <28 IRQ_TYPE_NONE>;
P00 { gpio-hog; gpios = <0 GPIO_ACTIVE_LOW>;
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> };
标签:hog,GPIO,pca9554,controller,内核,linux,interrupt,gpio 来源: https://www.cnblogs.com/dakewei/p/12322476.html