phintegrator Posted April 4, 2016 Posted April 4, 2016 Hi, Can anyone tell why I cant export PH3 as gpio? It is the default "usb2_vbus-supply" for usb2 of allwinner A20. In my application I need to control this "usb2_vbus-supply". Example : exporting PH3 root@cubieboard2:~# echo 227 > /sys/class/gpio/export -bash: echo: write error: Device or resource busy Im using armbian vanilla for my cb2. Thanks in advance.
tkaiser Posted April 4, 2016 Posted April 4, 2016 PH3 is defined in sunxi-common-regulators.dtsi and used in sun7i-a20-cubieboard2.dts to define usb2_vbus-supply. I would suspect without changing these definitions you won't be able to switch the pin on/off from userspace?
phintegrator Posted April 20, 2016 Author Posted April 20, 2016 Hello Thomas, You're correct, after some modification in sunxi-common-regulators.dtsi and sun7i-a20-cubieboard2.dts, I can now control PH3 to be use in my application. Thanks.
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