To use the xbox 360 D-Pad in MAME you need to start xboxdrv using --dpad-as-button, then reconfigure MAME through the in-game interface. I got this working on my setup last night. Since I’m starting xboxdrv via rc,local the lines that start my controllers look like this:
xboxdrv --trigger-as-button --dpad-as-button --id 0 --led 2 --deadzone 4000 --silent &
