I am working on IMX53_smd (sabre tablet). since I was trying to toggle the LEDs in Linux ( charge and user debug D27, D32 from schematic ) which are connected to these pins :
But these definitions are already registered in "iomux-mx53.h" and "mx53_smd.c"
so I tried to access the pins directly from sysfs like this....
for MX53_PAD_EIM_D30__GPIO_30 : "echo 94 > /sys/class/gpio/export
But when I do ls i count see any new directory..
for MX53_PAD_PATA_DA_1__GPIO7_7 I did "echo 199 > sys/class/gpio/export
Here also No directories created... I dont understand why .. Is it because these pins are already being used for Charge_done and USER_DEBUG ??
Another case :
I thought I will access the free GPIO pin on the expansion connector,
that is 40th pin on J78 i.e. MX53_PAD_GPIO_17__GPIO7_12
So i Added this pin in "../mach-mx5/mx53_smd.c" in static iomux_v3_cfg_t mx53_smd_pads array..
then i recompiled the kernel and deployed it, booted from SD card.
But when I try to access it : echo 204 > export
echo out > gpio204/direction
echo 1 > gpio204/value
But when i see the value it is still '0' and the Pin doesnt change. but direction has changed to "out"
What am I doing wrong here ... ??