dev/input/jsX maps to the Joystick API interface and /dev/input/event* maps to the evdev ones (this also includes other input devices such as mice and keyboards).
Linux has two different input systems for Gamepads – the original Joystick interface and the newer evdev-based interface. (Discuss in Talk:Gamepad#Joystick API vibration support)
USB GENERIC GAMEPAD DRIVER HOW TO
Reason: Need info about differences between API, how to switch between them.