I'm usually running Mainline, but in this case, I've rebooted with a Legacy, the "orangepilite 3.4.112-sun8i" and gave it a try.
It didn't worked with gpio5, but was working perfectly with gpio110.
So, since you got "Device or resource busy" using gpio110, we need more details :
Did you tried gpio110 right after reboot (because it could be "busy" by some other apps) ?
What kind is your board exactly ?
Is your 3.4 coming from Armbian ? (which subversion ?)
EDIT : what "cat /sys/kernel/debug/gpio" is showing ?
