This is a linux kernel module for the Raspberry Pi demonstrating how to switch on and off a GPIO pin. This has been compiled with kernel source version 3.8.10.
There is also a demonstration application to show userspace control called blinktimer.c
dbfr3qs/blinkdevice
Example of a kernal module for the Raspberry Pi. The module allows switching GPIO pin 4 high or low in userspace.
C