I have a D525 Intel Atom (http://www.amazon.ca/Jetway-NF38QLB-525-Generation-Intel-1-80GHz13W/dp/B00ABZRTDU) which appears to have GPIO pins.
I am using the 4.2 Linux kernel and can see the directory /sys/class/gpio/ (this appeared after updating to 4.2) however I cannot seem to interact with the GPIOs. I have followed instructions here: https://www.ridgerun.com/developer/wiki/index.php/How_to_use_GPIO_signals however I just get the following error when trying to export the gpio
root@wheezy7.8:/# cd /sys/class/gpio/
root@wheezy7.8:/sys/class/gpio# GPIO=1
root@wheezy7.8:/sys/class/gpio# echo $GPIO > export
bash: echo: write error: Invalid argument
I have tried numerous pin numbers (1-32), but no luck...
Here is the output from modinfo gpio_ich
root@wheezy7.8:/sys/class/gpio# modinfo gpio_ich
filename: /lib/modules/4.2.0-040200-generic/kernel/drivers/gpio/gpio- ich.ko
alias: platform:gpio_ich
license: GPL
description: GPIO interface for Intel ICH series
author: Peter Tyser <ptyser@xes-inc.com>
srcversion: 338BC4F9B47008C478E28F3
depends:
intree: Y
vermagic: 4.2.0-040200-generic SMP mod_unload modversions 686
parm: gpiobase:The GPIO number base. -1 means dynamic, which is the default. (int)
I have also dumped the configuration (following instructions from the first link):
root@wheezy7.8:~$ mount -t debugfs none /sys/kernel/debug
root@wheezy7.8:~$ cat /sys/kernel/debug/gpio
GPIOs 462-511, platform/gpio_ich.1.auto, gpio_ich:
This seems to suggest that the pins are 462 to 511, which is not the case:
root@wheezy7.8:/sys/class/gpio# GPIO=462
root@wheezy7.8:/sys/class/gpio# echo $GPIO > export
bash: echo: write error: No such device
root@wheezy7.8:/sys/class/gpio# GPIO=511
root@wheezy7.8:/sys/class/gpio# echo $GPIO > export
bash: echo: write error: No such device
