Re: [PATCH] new driver for ITM Touch touchscreen

Dmitry Torokhov
2005-03-04T17:00:10Z

On Fri, 04 Mar 2005 17:20:24 +0100, Hans-Christian Egtvedt <hc@mivu.no> wrote:
> On Fri, 2005-03-04 at 09:52 -0500, Dmitry Torokhov wrote:
> > On Fri, 4 Mar 2005 14:03:37 +0200, Alexey Dobriyan <adobriyan@mail.ru> wrote:
> > > On Friday 04 March 2005 12:30, Hans-Christian Egtvedt wrote:
>
> <snip info about kref>
>
> > As far as the driver goes:
> >
> > - yes, it does need input_sync;
>
> One problem with input_sync is that the panel get's too fast, and double
> click is experienced quite often, maybe some threshold is needed for low
> values in Z-direction?
>
> I'm probably doing something wrong here since I experience easy
> doubleclicks when I just lightly touch the screen.
>

Yes, I think you need to use some threshold when reporting BTN_TOUCH
event. Still, always report ABS_PRESSURE as is. This way the
touchscreen is useable via legacy interfaces (mousedev. tsdev) and if
a specialized userspace driver is written it still can get pretty much
unmangled data from /dev/input/eventX. This will also allow such
driver adjust touchpad sensitivity, if needed.

> > Also, is there a way to query the screen for actual size?
>
> Sorry, the panel is a fixed size, and it gives out coordinates from 0 ->
> 4095 in both X- and Y-direction. In Z-direction (pressure strength) it
> goes from 0 to 255.
>
> Or did you want the size of the screen? Meaning you want to know if it's
> a 15", 17" and so on?
>

No, not physical sizes. I was wondering if soe touchscreens are
reporting let's say actual coordinates from 1100-3600 and others from
600-3850, instead of full 0-4096. Is there a way to query the hardware
and find the actual min and max for a device so it can be reported to
userspace.

--
Dmitry

P.S. When you post the updated version could you please CC Vojtech
Pavlik <vojtech@suse.cz> as he is the current input system maintainer
and linux-input mailing list at linux-input@atrey.karlin.mff.cuni.cz.
Thanks!