Enabling / reading from GPIO on GMB-N270G2-S6A1E
I am very new to GPIO on Linux. I have an Advantech board GMB-N270G2-S6A1E and would like to make use of the on-board GPIO. According to the board datasheet, it is using NXP 9555 for the 16-bit GPIO.
What is supposed to be the proper way of detecting / confirming the GPIO chip from Linux, and how do I perform a test that the GPIO is indeed working?
I read about performing "echo some_value > /sys/class/gpio/export", but what should the some_value be?