Re: [PATCH 09/10] dt-bindings: input: touchscreen: stmpe: add tracking index

["Middelschulte, Leif" <Leif.Middelschulte@klsmartin.com>]

Am Freitag, den 14.06.2019, 13:58 -0600 schrieb Rob Herring:
> On Mon, May 27, 2019 at 06:19:37PM +0200, Leif Middelschulte wrote:
> > The tracking index is a "minimum" distance two touch
> > points need to have in order for the second to be valid.
> > This adds the corresponding binding property documentation.
> > 
> > Signed-off-by: Leif Middelschulte <
> > leif.middelschulte@klsmartin.com
> > >
> > ---
> >  .../bindings/input/touchscreen/stmpe.txt          | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> > index 09d2d4f288cc..8696af35a7b8 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/stmpe.txt
> > @@ -42,6 +42,21 @@ Optional properties:
> >  				The given window also affects the value range (limits) set
> >  				within the input subsystem which, in turn, affects
> >  				the input resolution calculation on both axes.
> > +- st,tracking-index	: Minimal distance between the current touch position and the previous
> > +				touch position. If the distance is shorter than the tracking
> > +				index, it is discarded. The tracking is calculated by summation
> > +				of the horizontal and vertical movement.
> > +				If pressure reporting is enabled (X/Y/Z), an increase in pressure
> > +				override the movement tracking and report the new data set, even
> > +				if X/Y is within the previous tracking index.
> > +				0 -> disabled
> > +				1 -> 4
> > +				4 -> 8
> > +				3 -> 16
> > +				4 -> 32
> > +				5 -> 64
> > +				6 -> 92
> > +				7 -> 127
> 
> This is what touchscreen-fuzz-x/y is for.

The stmpe touchcontroller does not support handling each axis separately.
Also it is not to be mistaken in its specific behavior (i.e. override)
for the general `fuzz` parameter. However, should I rename it to `st,fuzz-x-y` or similar?

AFAICS there[0] is no generic combined devicetree property, is there?

[0]https://www.kernel.org/doc/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

> 
> >  - touchscreen-inverted-x: X axis is inverted (boolean)
> >  - touchscreen-inverted-y: Y axis is inverted (boolean)
> >  - touchscreen-swapped-x-y: X and Y axis are swapped (boolean)
> > -- 
> > 2.21.0
> >