Re: ads7846 touchscreen: fix pressure

Dmitry Torokhov
2009-10-09T16:35:58Z

On Thu, Oct 08, 2009 at 11:24:33AM +0200, Pavel Machek wrote:
> On Thu 2009-10-08 10:39:39, Trilok Soni wrote:
> > Hi Pavel,
> >
> > On Wed, Oct 7, 2009 at 1:24 AM, Pavel Machek <pavel@ucw.cz> wrote:
> > >
> > > On Zaurus, pressure is reported inverted -- the lighter the pressure,
> > > the bigger numerical value. This should fix it.
> > >
> > > Signed-off-by: Pavel Machek <pavel@ucw.cz>
> > >
> > > --- linux-rc/drivers/input.ofic/touchscreen/ads7846.c   2009-10-06 13:49:56.000000000 +0200
> > > +++ linux-rc/drivers/input/touchscreen/ads7846.c        2009-10-06 21:18:25.000000000 +0200
> > > @@ -608,12 +609,12 @@
> > >
> > >                input_report_abs(input, ABS_X, x);
> > >                input_report_abs(input, ABS_Y, y);
> > > -               input_report_abs(input, ABS_PRESSURE, Rt);
> > > +               input_report_abs(input, ABS_PRESSURE, ts->pressure_max-Rt);
> >
> > but same behavior is seen by others using this chip on different
> > boards? If not, this has to be done through platform data.
>
> Well, I'd expect the chip to behave in similar way on all
> platforms. Of course, it would be good if someone with different hw
> tested it, but I do not have that hw...
>
> So I guess the best way is to make it go in early and see how it does
> in testing....

No, this is not how it works. Please do

git log -- drivers/input/touchscreen/ads7846.c

and try to check with people who were working on this driver. I somehow
doubt that they'd overlook such obvious issue as inverted pressure
readings.

--
Dmitry