Following Grumbel's answer, I tried *xboxdrv solution with the support of this website and especially this page:

1. Install xboxdrv 0.8.2 from Ubuntu Software Center.

   
   

   Install also uinput and joydev if needed. I did it this way:

   
   

   sudo modprobe uinput
   
   sudo modprobe joydev
   
   

   
   



2. Need to know the event of the gamepad:

   
   

   Launch udevadm monitor --udev and then plug the game pad:

   
   

   $ udevadm monitor --udev
   
   monitor will print the received events for:
   
   UDEV - the event which udev sends out after rule processing
   
   
   
   UDEV  [6722.377700] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1 (usb)
   
   UDEV  [6722.383264] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0 (usb)
   
   UDEV  [6722.383333] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0/0003:046D:C218.0003 (hid)
   
   UDEV  [6722.383389] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0/0003:046D:C218.0003/hidraw/hidraw1 (hidraw)
   
   UDEV  [6722.387123] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0/input/input10 (input)
   
   UDEV  [6722.399284] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0/input/input10/event8 (input)
   
   UDEV  [6722.412128] add      /devices/pci0000:00/0000:00:1d.3/usb5/5-1/5-1:1.0/input/input10/js0 (input)
   
   

   
   

   I conclude that my gamepad's event is /dev/input/event8

   
   



3. Display names of every key, axis, button of the gamepad.

   
   

   The idea is to launch xboxdrv and test every button and note the result on paper.

   
   

   $ sudo xboxdrv --evdev /dev/input/event8 --evdev-debug
   
   Your Xbox/Xbox360 controller should now be available as:
   
   /dev/input/js1
   
   /dev/input/event9
   
   Press Ctrl-c to quit, use '--silent' to suppress the event output
   
   EV_ABS ABS_X 128
   
   EV_ABS ABS_Y 128
   
   ...
   
   

   
   

   In my case the result is:

   
   

   

   
   



4. Set the config file

   
   

   Create an xboxdrv-mouse.ini file to set X Y axis and left and right mouse button.

   
   

   Here I set gamepad buttons 2 for left mouse button and 3 for right mouse button:

   
   

   [xboxdrv]
   
   evdev=/dev/input/event8
   
   silent=true
   
   
   
   [evdev-absmap]
   
   ABS_X=x1
   
   ABS_Y=y1
   
   
   
   [ui-axismap]
   
   x1=REL_X:10
   
   y1=REL_Y:-10
   
   
   
   [evdev-keymap]
   
   BTN_THUMB=a
   
   BTN_THUMB2=b
   
   
   
   [ui-buttonmap]
   
   a=BTN_LEFT
   
   b=BTN_RIGHT
   
   
   
   # EOF #
   
   

   
   

   Note that value for REl_X and REL_Y seems to define the speed of the mouse, and by defining a negative value it inverts the axis (see here for REL_Y)

   
   

   Another example with more button definition

   
   

   [xboxdrv]
   
   evdev=/dev/input/event8
   
   silent=true
   
   
   
   [evdev-absmap]
   
   ABS_X=x1
   
   ABS_Y=y1
   
   ABS_HAT0X=x2
   
   ABS_HAT0Y=y2
   
   
   
   [ui-axismap]
   
   x1=REL_X:10
   
   y1=REL_Y:-10
   
   x2=KEY_LEFT:KEY_RIGHT
   
   y2=KEY_DOWN:KEY_UP
   
   
   
   [evdev-keymap]
   
   BTN_TRIGGER=x
   
   BTN_TOP=y
   
   BTN_THUMB=a
   
   BTN_THUMB2=b
   
   BTN_PINKIE=rt
   
   BTN_BASE2=rb
   
   BTN_TOP2=lt
   
   BTN_BASE=lb
   
   BTN_BASE3=back
   
   BTN_BASE4=start
   
   
   
   [ui-buttonmap]
   
   x=KEY_KPENTER
   
   y=KEY_SPACE
   
   a=BTN_LEFT
   
   b=BTN_RIGHT
   
   rt=KEY_KP8
   
   rb=KEY_KP2
   
   lt=KEY_KP6
   
   lb=KEY_KP4
   
   back=KEY_LEFTSHIFT
   
   start=KEY_RIGHTCTRL
   
   
   
   # EOF #
   
   
   
   

   
   



5. Launch it

   
   

   sudo xboxdrv --config xboxdrv-mouse.ini
   
   

   
   

   To avoid launching it with sudo, create a udev rule.

   
   

CONCLUSION

It works fine, it's the best solution for me.