View source for Aria Ti am335x GPIO control

==Control GPIO via Shell==
To control GPIO3_21, we need to control on gpio117 (32*3+21 = 117)

===init (only do once)===
 # mount -t debugfs none /sys/kernel/debug  #mount debugfs
 # echo 7 > /sys/kernel/debug/omap_mux/mcasp0_ahclkx #pinmux to mode 7 (gpio mode)
 # echo 117 > /sys/class/gpio/export #export the pin
 # echo out > /sys/class/gpio/gpio117/direction #set direction, out or in
===on and off===
 # echo 1 > /sys/class/gpio/gpio117/value #on
 # echo 0 > /sys/class/gpio/gpio117/value #off

==LED Blink test==
 # while true;do echo 1 > /sys/class/gpio/gpio117/value ; sleep 1 ;echo 0 > /sys/class/gpio/gpio117/value ;sleep 1 ;done