Re: [PATCH 3/5] dt-bindings: add more optional properties for elan_i2c touchpads

[Benjamin Tissoires]

On Wed, Oct 17, 2018 at 10:15 PM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Fri, Oct 12, 2018 at 04:24:11PM +0200, Benjamin Tissoires wrote:
> > Some new touchpads IC are connected through PS/2 and I2C. On some of these
> > new IC, the I2C part doesn't have all of the information available.
> > We need to be able to forward the touchpad parameters from PS/2 and
> > thus, we need those new optional properties.
> >
> > Link: https://bugzilla.redhat.com/show_bug.cgi?id=1628715
> > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> > ---
> >  Documentation/devicetree/bindings/input/elan_i2c.txt | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/input/elan_i2c.txt b/Documentation/devicetree/bindings/input/elan_i2c.txt
> > index 797607460735..ace6bcb0b4eb 100644
> > --- a/Documentation/devicetree/bindings/input/elan_i2c.txt
> > +++ b/Documentation/devicetree/bindings/input/elan_i2c.txt
> > @@ -13,6 +13,14 @@ Optional properties:
> >    pinctrl binding [1]).
> >  - vcc-supply: a phandle for the regulator supplying 3.3V power.
> >  - elan,trackpoint: touchpad can support a trackpoint (boolean)
> > +- elan,clickpad: touchpad is a clickpad (the entire surface is a button)
>
> > +- elan,max_x: the maximum reported value on the X axis
> > +- elan,max_y: the maximum reported value on the Y axis
> > +- elan,min_x: the minimum reported value on the X axis
> > +- elan,min_y: the minimum reported value on the Y axis
> > +- elan,x_res: the resolution of the X axis (in units per mm)
> > +- elan,y_res: the resolution of the Y axis (in units per mm)
> > +- elan,width: max reported width of a blob
>
> Can't we use standard touchscreen properties here? (Yes, I get this is a
> touchpad, not touchscreen).

Hey Rob,

Well, there is that (it's a touchpad driver) and we can't also really
use the of_touchscreen.c implementation.
If both concerns are not an issue, we can then move the [min/max/res]
properties to the touchscreen ones.

Regarding 'elan,width', this is something missing from the standard ts
properties, and AFAICT, this controls the maximum reported
width/height of a touch.
I should probably rename them to max_width, max_height.

Hans, do you think we should add such properties to of_touchscreen.c
too? (the width/height ones)

Cheers,
Benjamin