Fitlet GPIO SDK for Linux
From fit-PC wiki
Installation
- Download the kernel image and kernel headers to the fitlet.
- Open the terminal and install the new linux-*.deb packages:
$ sudo dpkg -i /path/to/linux-*.deb
- Reboot the system:
$ sudo reboot -f
fitlet GPIO
- GPIO interface on fitlet consists of 9 I/Os provided by AMD FCH (Fusion Controller Hub)
- The responsible kernel module is gpio_fch
- The kernel modules uses the following pin naming convention:
GPIO name | HW source | Pin on GPIO Connector | Notes |
GPIO89 | FCH | P-1 | |
GPIO132 | FCH | P-2 | |
GPIO65 | FCH | P-3 | |
GPIO66 | FCH | P-4 | |
GPIO29 | FCH | P-5 | Vout 1.5V |
GPIO73 | FCH | P-8 | |
GPIO27 | FCH | P-9 | Vout 1.5V |
GPIO28 | FCH | P-10 | Vout 1.5V |
GPIO12 | FCH | P-11 |
- The GPIO sysfs interface allows users to manipulate any GPIO from userspace dynamically.
- A basic example of GPIO usage (as root user):
$ modprobe fch_gpio $ echo 89 > /sys/class/gpio/export $ echo out > /sys/class/gpio/gpio89/direction $ echo 1 > /sys/class/gpio/gpio89/value ## at this point voltage measuring on P-1 should give 3.3V $ echo 0 > /sys/class/gpio/gpio89/value ## at this point voltage measuring on P-1 should give 0.0V $ echo 89 > /sys/class/gpio/unexport
- The source code of gpio_fch driver fitlet.gpio.3.16.diff
- The GPIO framework and GPIO sysfs interface are documented in Linux Kernel Documentation :: GPIO