phintegrator Posted April 4, 2016 Share 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. Link to comment Share on other sites More sharing options...
tkaiser Posted April 4, 2016 Share 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? Link to comment Share on other sites More sharing options...
phintegrator Posted April 20, 2016 Author Share 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. Link to comment Share on other sites More sharing options...
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