The following links will help you set up the USB interface with the Raspberry Pi.

http://ithink.ch/blog/2013/09/08/patching_the_linux_kernel_to_install_the_xin-mo_dual_arcade_driver_on_a_raspberry_pi.html

http://code.google.com/p/mame4all-pi/issues/detail?id=17

 

The following links will help you set up the USB interface with the Raspberry Pi / B / 2

http://www.raspberrypi.org/forums/viewtopic.php?f=78&t=99081

The following links will help you set up the USB interface for two players.

Xin Mo Interface two player set up.