how to use ps2 usb controller?

[killerhaha100]

Im a bit looking for a physical gamepad when i bump to ps3 controller but it seems your device need to be rooted which is not im doing but i saw ps2 controller works on emulators with keymapping and ppsspp is perfect for it but do you need an app to make that work base on what i saw you just need ps2 controller and otg cable and do you need a specific android os for it to work since my device is running only on 2.3.6 gingerbread