I'm working with the imx6 GPIO driver on Wandboard Quad, using the gpio_led run file as a smoke test. Unfortunately, I've had only limited success controlling the GPIO pins exported to the Wandboard's JP-4. It is unclear where these pins map in the Genode imx6 driver (18.05, nova). In Linux, I can successfully toggle them all via /sys/class/gpio.
The imx6 driver allows for 32 pins to be set to high or low and I have modified the run file and the main.cc file to blink sets of pins rather than just a single pin. If I set all 32 pins as output with an initial value of "0" in the run file and then blink the following sets of pins I see these results:
0-31: I read 3 pins blinking with a voltage meter 0-15: I read 2 pins blinking 0-6: I read no pins blinking 7-15: I read no pins blinking
It seems as though it takes combinations of pins set to high and low at the same time to get a reading of high or low off of a particular pin, but I cannot divine the pattern. This leads me to think that there is a step missing in the initial configuration.
Does anyone have a suggestion of what step I am missing to get predictable results?