I am using Colibri iMX6 DL module + Iris carrier board + Colibri_iMX6_LinuxImageV2.6_20160630,
I have made the following setup to test GPIO interrupts using sysfs:
Exported GPIO number 15 as output, on extension connector X16 pin 13.
Exported GPIO number 51 as input along with both edges as interrupts, on extension connector X16 pin 19.
Connected a jumper wire to these two pins.
Now driving output on /sys/class/gpio/gpio15/value and capturing input on /sys/class/gpio/gpio51/value works fine, however if I use either the poll or select method described here: gpio.txt « Documentation - linux-toradex.git - Linux kernel for Apalis and Colibri modules, to detect interrupt on gpio51 then it doesn’t work.
With select exceptfds, call remains blocked for either edge signal.
With poll, call immediately returns with POLLPRI event even when there is no signal change.
I tried setting the interrupt edge type to rising, falling in /sys/class/gpio/gpio51/edge, but same issue.
Am I missing some configuration? Can you please provide/point to an GPIO interrupt example in userspace for linux platform?