Gunze AHL/M serial touchscreen not working in xorg/lubuntu with old modules/drivers

Question

I'm trying to setup the Gunze AHL/M serial touchscreen (Panasonic Toughbook CF-M34) on xorg 2:1.18.3-lubuntu2.2 without success.

The touchscreen is on /dev/ttyS3 and if I

sudo od /dev/ttyS3 

I can see it's up and running.

It used to work in old Debian (I think it was Woody) and Xfree 4.0, console (with GPM) and X (with gunzets drivers from http://www.linux.it/~rubini/software/gunzets/gunzets.html).

The same configuration in GPM and in X now is not working.

I tried with inputattach but it has no gunze driver support.

I tried with the Xfree 4.0 configuration of xorg adding:

Section "InputDevice"
Identifier "Touchscreen0"
Driver "gunze"
Option "Device"            "/dev/ttyS3"
#Option "DeviceType"       "serial"
Option "BaudRate"          "9600"
Option "Smoothness"        "9"
Option "TappingDelay"      "0"
Option "JitterDelay"       "50"
Option "DebugLevel"        "0"
Option "Res12Bit"          "False"
Option "SendCoreEvents"

EndSection

to a file in /usr/share/X11/xorg.conf.d/, copying the file xf86Gunze.so in /usr/lib/xorg/modules/input and adding:

InputDevice "Touchscreen0" "Pointer"

to Section "ServerLayout".

I also tried with the old working configuration from Xfree 3.3, same problem.

I tried to

modprobe gunze

and lsmod|grep gunze show it is loaded.

/var/log/Xorg.0.log shows no signs of loading gunze or /dev/ttyS3, I think everything is managed by evdev but even if I specify /dev/ttyS3 in the evdev xorg.conf.d file in the touchscreen section, nothing changes.

xinpunt does not show anything but touchpad, keyboard, power buttons.

I think I'm missing something so I'm asking to you:

is this the right procedure to make a serial touchscreen work?

if not, what I need to make it work?

is it possible to use Xfree 3.3/4.0 modules on Xorg?

what is the right way to add an input device to modern Xorg?

Any clue on why it is not working and how to make it work?

Thank you very much for your help.