Re: [PATCH 2/3] input: touchscreen: of: Register multitouch axes

From: Maxime Ripard
Date: Thu Nov 06 2014 - 11:10:10 EST


Hi,

On Wed, Nov 05, 2014 at 09:56:35AM -0800, Dmitry Torokhov wrote:
> On Wed, Nov 05, 2014 at 04:07:49PM +0100, Maxime Ripard wrote:
> > So far, the DT parsing code was only setting up the regular input axes,
> > completely ignoring their multitouch counter parts.
> >
> > Fill them with the same parameters than the regular axes.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/input/touchscreen/of_touchscreen.c | 12 +++++++++---
> > 1 file changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/input/touchscreen/of_touchscreen.c b/drivers/input/touchscreen/of_touchscreen.c
> > index 74d6b0eb50ac..cf2a753edd96 100644
> > --- a/drivers/input/touchscreen/of_touchscreen.c
> > +++ b/drivers/input/touchscreen/of_touchscreen.c
> > @@ -42,17 +42,23 @@ void touchscreen_parse_of_params(struct input_dev *dev)
> >
> > maximum = of_get_optional_u32(np, "touchscreen-size-x");
> > fuzz = of_get_optional_u32(np, "touchscreen-fuzz-x");
> > - if (maximum || fuzz)
> > + if (maximum || fuzz) {
> > input_set_abs_params(dev, ABS_X, 0, maximum, fuzz, 0);
> > + input_set_abs_params(dev, ABS_MT_POSITION_X, 0, maximum, fuzz, 0);
>
> Not all devices are multitouch so you shoudl not be setting multitouch
> bits unconditionally.

Hmmm, right.

> In I think we should rely on driver to set capability bits properly and
> then here test them and apply the readings. Probably also issue a
> warning if we see max/fuzz setting but neither ABS_<N>/ABS_MT_<N>
> capabilities.

What I was aiming at was to avoid DT parsing duplication for the
!multitouch and multitouch axis. I don't think there's a way to copy
the parameters.

The mt_init_slots might be a solution, but it does the copy the other
way around: from the multitouch to the !multitouch axis, and without
enabling it, which renders using both input_mt_init_slots and the
of_touchscreen code together impossible.

Is there a way to just enable an axis without calling
input_set_abs_params? Is __set_bit enough?

Thanks,
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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