GPIO interrupt

Hi, I'm using openwrt on an AR9344 chip. Mine is a GPIO interrupt triggered application.I believe I can achieve this by using poll(2) and sysfs gpio. But the problem is, my poll call is continuosly blocked. From what I understand, poll() depends on the edge file in the sysfs directory (/sys/class/gpiox/edge). But this file is missing. From the sysfs documentation (linux kernel):
"edge" ... reads as either "none", "rising", "falling", or
"both". Write these strings to select the signal edge(s)
that will make poll(2) on the "value" file return.

	This file exists only if the pin can be configured as an
	interrupt generating input pin.

Does this mean that there's something wrong with the GPIO driver? I tried exporting with multiple GPIO pins and only /value, /direction, /uevent files are present. From the little information I read in all the forum, the GPIO interrupt would be supported by all kernels post 2.8.x.x version. My kernel version is Is there any way I can configure this thing to work correctly?

Any help would be really appreciated. Thanks in advance.

What version of OpenWrt?

What device?

The OS version is 17.01.4. Device is a custom made module.