GPIO access

Based on my current knowledge, the access to GPIO is related to the following files.

arch/arm/plat-omap/include/mach/mux.h
####This file defines the name of the GPIO

arch/arm/mach-omap2/mux.c
####This file defines the register of the GPIO

include/linux/input.h
####Key definations

arch/arm/mach-omap2/board-omap3beagle.c
####This file init the board.