3)RST脚与POWER脚是pca 9534扩展出来的IO脚;
PCA9534 i2c地址是linux代码里面的是实际的除以2故为0X20
4.故板级dts上添加如下
设备树里添加扩展IO的节点pca9534_gpio以及电磁屏的节点viewsonic
&i2c4{
status = "okay";
/*扩展IO配置*/
pca9534_gpio:pca9534_gpio@20 {
compatible = "nxp,pca9534";
reg = <0x20>;
#gpio-cells = <0x2>;
pinctrl-names = "default";
//interrupt-parent = <&gpio3>;
//interrupts = <23 IRQ_TYPE_LEVEL_LOW>;
status = "okay";
};
//viewsonic 电磁屏
viewsonic:viewsonic@37{
compatible = "viewsonic_i2c";
reg = <0x37>;
power_gpio = <&pca9534_gpio 2 GPIO_ACTIVE_HIGH>;
irq_gpio = <&gpio1 23 IRQ_TYPE_LEVEL_LOW>;//gpio1_c7
reset_gpio = <&pca9534_gpio 1 GPIO_ACTIVE_LOW>;
//cfg_gpio = <&gpio7 10 IRQ_TYPE_LEVEL_LOW>;//<&touch_cfg_gpio>;//
status = "okay";
};
};