writing to /sys/class/gpio/export failing

Question

I am working on a project which needs me to configure the gpio pins and add sensors to atom board. The kernel has configured the gpio ... CONFIG_GPIO_SYSFS=y is one of the kernel options.

I am using fedora version 2.6.29-10
But i am not able to write to export file in gpio folder using

GPIO=22  // to add pin 22 to userspace  
echo $GPIO > /sys/class/gpio/export

I get the error
bash: echo: write error: Invalid argument

I also tried the same with sudo and sh -c but no use ,unless i can expose these pins to userspace i cant write any code.What am i doing wrong?
Is the problem with the kernel version or some other kernel options needs to set??

Thanks in advance

Answer 1

Well , for the GPIO pins to be used as I have described. you need to load a module using insmod or modprobe. After a long wait i got those modules from the manufacturers of our atom board. The problem described above is now solved.