Implementation of libgpiod in embedded Linux with Kernel 5.4 on DART6ul

Question

I'm working on a DART6UL iMX6-based SoM with Kernel 5.4. Previously, I worked on the same board with previous release of Kernel (3.1): to manage GPIO a friend used some utilities from GUMSTIX (gpio and gpio-event-drv based on /sys/class/gpio), because he found easier to manage GPIO. Now I read, for Kernel newer than 4.8, the old /sys/class/gpio was deprecated and better to use libgpiod library. How to implement in my filesystem? Do I have to compile as module or is it already inserted as driver? Launching as NFS and entering as root it seems doesn't be present (ls /dev doens't find any gpiochip). Once obtained the GPIO management as gpiochip according to libgpiod, I need to implement in my program: previously I included both header and put "c" files in my program. Does I am to do the same? The best would be a step-by-step guide to do this... Is there anyone who has faced with the same issue? Paolo