GPIO PIN base address calculation had double right shift, thus call
to SAM_PION_BASE was always with port = 0 instead of correct port
number. As a result, function sam_gpioirq didn't correctly configure
additional interrupt modes (only rising or falling edge and level
interrupts).
The issue occured on SAMv7 and SAM34 platforms (likely copy-pasted
from one to another).
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
b3656d34b6