Re: [PATCH v3 2/5] dt-bindings: input/touchscreen: Add compatible for IST3038B

From: Karel Balej
Date: Wed Dec 27 2023 - 06:56:21 EST


Markuss,

On Sat Dec 9, 2023 at 11:58 AM CET, Conor Dooley wrote:
> On Sat, Dec 09, 2023 at 10:05:27AM +0100, Karel Balej wrote:
> > On Mon Dec 4, 2023 at 1:52 PM CET, Conor Dooley wrote:
> > > On Mon, Dec 04, 2023 at 02:40:44PM +0200, Markuss Broks wrote:
> > > > On 12/3/23 13:20, Conor Dooley wrote:
> > > > > On Sat, Dec 02, 2023 at 01:48:33PM +0100, Karel Balej wrote:
> > > > > > From: Markuss Broks <markuss.broks@xxxxxxxxx>
> > > > > >
> > > > > > Imagis IST3038B is a variant (firmware?) of Imagis IST3038 IC,
> > > > > > add the compatible for it to the IST3038C bindings.
> > > > > This one is better, but would be well served by mentioning what
> > > > > specifically is different (register addresses or firmware commands?)
> > > >
> > > > I don't think anyone knows this other than Imagis itself. I would guess it's
> > > > different hardware, since register addresses are indeed different, but on
> > > > the other hand, there is a possibility that firmware on the MCU could be
> > > > responding to those commands. I suppose "... IST3038B is a hardware variant
> > > > of ... IST3038" would be more correct.
> > >
> > > Only Imagis might know the specifics, but you (plural) have made driver
> > > changes so you know what is different in terms of the programming model.
> > > I'm just asking for you to mention how the programming model varies in
> > > the commit message. Otherwise I can't know whether you should have added
> > > a fallback compatible, without going and reading your driver change. The
> > > commit message for the bindings should stand on its own merit in that
> > > regard.
> > > "Variant" alone does not suffice, as many variants of devices have a
> > > compatible programming model, be that for a subset of features or
> > > complete compatibility.
> > >
> > > > The reason why I think it could be firmware-defined is because we have a lot
> > > > of variants (30xxA, 30xxB, 30xxC, plain 30xx), and the numbers usually mean
> > > > feature level/completeness, e.g. some don't support the touch pressure or
> > > > touchkeys, and we don't know what A/B/C/none means.
> > >
> > > Ultimately whether it is due to firmware or the hardware isn't
> > > particular important, just mention what is incompatibly different.
> >
> > I propose to update the commit description as such:
> >
> > Imagis IST3038B is a variant (firmware?) of Imagis IST3038 IC
> > differing from IST3038C in its register interface. Add the
> > compatible for it to the IST3038C bindings.

is this change OK with you?

>
>
> SGTM. You can add
> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> with that commit message update.
>
> Thanks,
> Conor.

Kind regards,
K. B.