PS3 USB controllers, such as the Logitech Chillstream PS3 work out-of-the-box on Arch. Simply pluging one in into a usb port is enough to have it working on games that have gamepad support (This was tested on Dolphin and Jamestown.
Disable Joystick From Controlling Mouse
If you want to play games with your controller, you might want to disable gamepad control over mouse cursor. To do this, edit /etc/X11/xorg.conf.d/50-joystick.conf so that it looks like this:
Section "InputClass" Identifier "joystick catchall" MatchIsJoystick "on" MatchDevicePath "/dev/input/event*" Driver "joystick" Option "StartKeysEnabled" "False" #Disable mouse Option "StartMouseEnabled" "False" #support EndSection