Re: [PATCH] Input: atmel_mxt_ts - support KoD knob

[Nick Dyer <nick@shmanahar.org>]

On Thu, 16 Jan 2025 at 03:03, Marek Vasut <marex@denx.de> wrote:
>
> On 1/16/25 2:01 AM, Dmitry Torokhov wrote:
> > On Mon, Jan 13, 2025 at 09:08:47PM +0100, Marek Vasut wrote:
> >> On 1/13/25 8:43 PM, Dmitry Torokhov wrote:
> >>> How about creating separate input devices for these?
> >> This is what I had originally, but ... why ?
> >>
> >> This is a single input device, touchscreen with up to two knobs , so why
> >> would it be multiple input devices ?
> >
> > So as you can see it is hard to express the knobs purpose within a
> > single input device. Additionally (as far as I understand) knobs are
> > not connected to the touchscreen function but rather rotary encoders
> > just happened to be mounted on the touchscreen. They are not considered
> > contacts.
>
>  From the touch controller perspective, they are contacts.
>
> > Therefore I think it makes sense to report them as 2 separate input
> > devices (maybe modeling after how drivers/input/misc/rotary-encoder.c
> > does things).
> Not really, the knobs also act as buttons, so the user might navigate a
> finger on the touch surface to point to an object, and turn or press the
> knob to trigger some action. This is similar to the Dell Canvas 27 knob
> already mentioned above, except that one was not glued to the glass, it
> was movable.

As an observation: atmel_mxt_ts already supports the T15 key array.
This turns an area of the matrix into a series of keys, which the
driver registers and will report in mxt_proc_t15_messages().

I think we see these as being similar to scrollwheels or side buttons
on a mouse - they are very associated with the pointing device itself.

Nick