Touch Screen Issues

[Erik Andersen]

(response below)

On Wed, Mar 24, 2010 at 02:51, Oliver Grawert <ogra at ubuntu.com> wrote:
> hi,
> if you talk about stylus and pointer i suspect you have a wacom tablet
> device (probably with a resistive touchscreen on top though) this is a
> very special case and totally different from a plain touchscreen. in
> wacom the input device is the external device (stylus, pointer etc)
> while on a touchscreen the pyhsical surface is the input device, input
> event translation and movement happen in a different way here.
>
> there are about 10 different "real" touchscreen chipset drivers out
> there of which we only support one or two.

So by this do you mean that there about 10 chipsets on the market and
we have drivers for one or two of them, or that there are Linux
drivers for 10 chipsets, but Ubuntu only has one or two drivers in it?

> the wacom drivers in turn are well supported and maintained since a
> while.
> the evtouch driver (which suports the widest range of touchscreens
> regardless of the connection (USB, serial etc) that i hacked up with
> quick hal workarounds in the intrepid cycle either needs porting to the
> new Xinput/udev model or the chipset drivers need to be ported on a
> kernel level to the usbtouchscreen driver so the general evdev X driver
> will pick them up.
>
> the former was the quick hack way to get anything at all (and porting
> might be as quick as well) while the latter is the right way (and what
> xorg upstream perfers to do) but the latter will take a lot more time
> and effort (though the latter indeed excludes all serial or PS/2
> attached touchscreens of which there are still a huge amount out there).
>
> there was a spec for this during last UDS but to my knowledge no work
> has been done regadring this spec.
>
> ciao
>        oli