XInput: Atmel maXTouch Digitizer touch screen

[Ben Bucksch]

I have unsuccessfully tried the whole day to configure the "Atmel 
maXTouch Digitizer" with USB ID 03eb:211c . This is a touch screen and 
does appear in X.org as input device. It is working rudimentary, but bad 
enough to be unusable.

The machine is a Samsung "Series 7 Slate" XE700T1A, a tablet with 
standard notebook hardware.
I am using Ubuntu 11.10 with Ubuntu kernel 3.0.0-14-generic and 
xorg-server 1.10.4-1ubuntu4.2.

Problems:


1. ABSOLUTE
By default, it's configured in Mode RELATIVE, but it's ABSOLUTE.
When I do
xinput --set-mode "Atmel Atmel maXTouch Digitizer" ABSOLUTE
it works.
But I need it at the login screen already.

I do not understand how to just change certain config options about an 
input device without changing the whole config.
When I put in /etc/X11/x.org.conf.d/atmel.conf :

Section "InputClass"
   Identifier  "Atmel touchscreen"
   MatchProduct "Atmel Atmel maXTouch Digitizer"
   MatchIsTouchpad "on"
   Option "Mode" "Absolute"
EndSection

then I get a complaint in the X.org log that the Driver is missing (yes, 
I shouldn't get that and I don't understand why I do). If I use Driver 
"synaptics", X.org log complains that it's not a synaptics device. If I 
use Driver "evdev", the clicking (mouse button, tapping) doesn't at all 
work anymore.

Either way, this should work OOTB. Can somebody please fix the driver to 
make it know that this device is ABSOLUTE?


2. Button not released

Sometimes, it generates only "button 1 pressed", but not "button 1 
released".

Strangely enough, this seems to happen only in "onboard" (the Ubuntu 
onscreen keyboard), but apparently not elsewhere. (I have no idea why.) 
Unfortunately, that makes my tablet completely useless, because the 
virtual keyboard then repeats the key endlessly and I can't type a 
single word. With xinput --test <deviceid>, verified that the "button 
released" event is (often) missing, when I use the onscreen keyboard.

I think this also is just a matter of a config tweak, but I haven't 
found which one.

Any help appreciated. I feel like I am this close to the dream on a 
Linux tablet, just some config tweaks, but too far to actually use it.

Ben