vincent.defert%posteo.net@localhost (Vincent DEFERT) writes:
I must be missing something, but have no clue what.
Could somebody shed some light on how I'm supposed to use the GPIO?
There are two ways.
Configure the GPIO once before boot with a modified device tree or
a device tree overlay.
Configure the GPIO once during boot in /etc/gpio.conf.
The configured pins can than be used (i.e. inputs queried, outputs
set to low or high) but you cannot reconfigure it. Reconfiguring at
run-time might sound interesting, but usually you have some other
hardware connected to the GPIO pins, and reconfiguration may even
damage the port. So in the real world, there are only very few
reasons to reconfigure at run-time.