@Akira:
These might be helpful for a start, but to tell you the truth, I would be happier if someone else with more knowledge than me would come up with a more or less readymade solution for the fleafpga Ohm. Either way, I will surely try to do somehing about it when I have the board.
http://blog.thestateofme.com/2012/08...gpio-joystick/
https://github.com/RetroPie/RetroPie...i/GPIO-Modules