Rock64 usb2.0 Power Control Floating GPIO Tutorial Files & Notes

[ds00]

Hi! I'm having kind of the opposite problem. I would like to switch/power off the USB power of both USB 2.0 and USB 3.0 as an efficient means to preserve energy on a battery powered system (I want to dump once a day stuff onto an attached hdd and power it on just for that occasion). I read the other thread as well, but did not find further information. My board is a version 2.0 Rock64.

Running gpioinfo
gpiochip0 - 32 lines:
       line   0:      unnamed       unused   input  active-high  
       line   1:      unnamed       unused   input  active-high  
       line   2:      unnamed "vcc-host-5v-regulator" output active-low [used]
       line   3:      unnamed       unused   input  active-high

shows me the expected GPIO line I read about to switch the USB ports in this thread. When trying gpioset gpiochip0 2=1
gpioset: error setting the GPIO line values: Device or resource busy

I get an error message (trying the same on the other GPIOs on that chip works as expected). As it was possible to change those settings in earlier times I'm wondering how to achieve that again. I was changing the boards DTB file for other systems (Orange Pi) to switch from OTG to normal USB ports following some tutorial. But I'm lost what to do for this board if that is actually required.

If I got it right from this (or the other post) the USB 3.0 cannot be switched off?

Thank you for any hints! Dirk