Yes, it's needed.
Even with the same encoder, adjusting steps affects rate of event generation.
(the steps defines 1 cycle of encoder rotation, and 1 cycle = 1 key event.)
On Sun, Jan 6, 2019 at 8:11 AM Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
>
> On Sat, Jan 5, 2019 at 2:27 PM Donghoon Han <nazgul33@xxxxxxxxx> wrote:
> >
> > Add DT binding document for rotary-encoder, keycode options.
> >
> > Signed-off-by: Donghoon Han <nazgul33@xxxxxxxxx>
> > ---
> > .../devicetree/bindings/input/rotary-encoder.txt | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt
> > index f99fe5cdeaec..113640079de3 100644
> > --- a/Documentation/devicetree/bindings/input/rotary-encoder.txt
> > +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt
> > @@ -12,6 +12,10 @@ Optional properties:
> > - rotary-encoder,relative-axis: register a relative axis rather than an
> > absolute one. Relative axis will only generate +1/-1 events on the input
> > device, hence no steps need to be passed.
> > +- rotary-encoder,relative-keys : generate pair of key events. This setting
> > + behaves just like relative-axis, generating key events. keycode[2]
> > + corresponds -1/1 events.
> > +- rotary-encoder,relative-keycodes : keycodes for relative-keys
> > - rotary-encoder,rollover: Automatic rollover when the rotary value becomes
> > greater than the specified steps or smaller than 0. For absolute axis only.
> > - rotary-encoder,steps-per-period: Number of steps (stable states) per period.
> > @@ -48,3 +52,11 @@ Example:
> > rotary-encoder,encoding = "binary";
> > rotary-encoder,rollover;
> > };
> > +
> > + rotary@2 {
> > + compatible = "rotary-encoder";
> > + gpios = <&gpio 21 0>, <&gpio 22 0>;
> > + rotary-encoder,relative-keys;
> > + rotary-encoder,relative-keycode = <103>, <108>;
> > + rotary-encoder,steps-per-period = <2>;
>
> Do you need steps for keys? They weren't required for the relative axis mode.
>
> Thanks.
>
> --
> Dmitry
--
한동훈 드림.
