GPIO IRQ for Meson gxbb

Hello, I am currently trying to use GPIO IRQ on Odroid-C2 board. I have compiled a working image having Linux Kernel 5.0.6. It has Pin-control driver and Interrupt Controller driver enabled. However, I am not getting any idea as to how should I request IRQ for a particular GPIO pin say for e.g. GPIOX.10. The "gpio_to_irq()" call is not working and it is returning "-6". I don't want to write a platform driver, I just want to write a simple out of tree character driver. I tried to get an idea from "drivers/gpio/", but they all seems to be platform driver. I would be really helpful if anyone can point me to a working gpio IRQ example for Linux 5.0.6 kernel. Thanks, Gaurav Pathak