Version 0.0.5-5 is going to be uploaded soon.

This release I tried to add joystick setup support by pressing the related buttons on the USB joystick.

This feature will only be shown if /dev/input/js0 is found. This character devices will be there if a USB joystick is connected or has been connected. During a reboot, this character device will be erased.

When you choose to set a key by pressing a joystick button, Gngeo-gui will keep waiting for input. After the button is pressed, Gngeo-gui will respond again to other input.
The analog part of the joystick is not supported during config, only the digital part.

How the X-axis and Y-axis are defined in gngeo is not totally clear to me, but the keypad does respond well in my configuration.

Furthermore I added two buttons in the confuration screen: p1 and p2 joystick device. They define to what devices the joystick for this player is attached. "0" means /dev/input/js0, 1 means dev/input/js1 etc. I don't know if anyone has experience with multiple joysticks (USB hub connected to the N900?), but I have not tested it.

For now, the player 2 joystick config is done by reading /dev/input/js0, just like for player 1.

@ivgalvez, since you where the one asking for this, would you be so kind and test the joystick setup on your own phone ?