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Date: Tue, 26 Mar 2024 19:28:17 +0000
From: Conor Dooley <conor@kernel.org>
To: Allen Lin <allencl_lin@hotmail.com>
Cc: Conor Dooley <conor.dooley@microchip.com>,
	Rob Herring <robh@kernel.org>, dmitry.torokhov@gmail.com,
	krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
	jikos@kernel.org, benjamin.tissoires@redhat.com,
	linux-input@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/4] dt-bindings: input: Add Himax HX83102J touchscreen
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On Tue, Mar 26, 2024 at 06:40:28PM +0800, Allen Lin wrote:
> Conor Dooley <conor.dooley@microchip.com> =E6=96=BC 2024=E5=B9=B43=E6=9C=
=8826=E6=97=A5 =E9=80=B1=E4=BA=8C =E4=B8=8B=E5=8D=884:48=E5=AF=AB=E9=81=93=
=EF=BC=9A
> >
> > On Tue, Mar 26, 2024 at 01:46:56PM +0800, Allen Lin wrote:
> > > Conor Dooley <conor@kernel.org> =E6=96=BC 2024=E5=B9=B43=E6=9C=8823=
=E6=97=A5 =E9=80=B1=E5=85=AD =E4=B8=8A=E5=8D=882:34=E5=AF=AB=E9=81=93=EF=BC=
=9A
> > > >
> > > > On Fri, Mar 22, 2024 at 01:30:09PM -0500, Rob Herring wrote:
> > > > > On Fri, Mar 22, 2024 at 05:54:08PM +0000, Conor Dooley wrote:
> > > > > > On Fri, Mar 22, 2024 at 04:56:03PM +0800, Allen_Lin wrote:
> > > > > > > Add the HX83102j touchscreen device tree bindings documents.
> > > > > > > HX83102j is a Himax TDDI touchscreen controller.
> > > > > > > It's power sequence should be bound with a lcm driver, thus it
> > > > > > > needs to be a panel follower. Others are the same as normal S=
PI
> > > > > > > touchscreen controller.
> > > > > > >
> > > > > > > Signed-off-by: Allen_Lin <allencl_lin@hotmail.com>
> > > > > >
> > > > > > note to self/Krzysztof/Rob:
> > > > > > There was a previous attempt at this kind of device. This versi=
on looks
> > > > > > better but might be incomplete given there's a bunch more prope=
rties in
> > > > > > that patchset:
> > > > > > https://lore.kernel.org/all/20231017091900.801989-1-tylor_yang@=
himax.corp-partner.google.com/
> > > > >
> > > > > Those don't look like properties we want coming back.
> > > >
> > > > Oh, I don't want most of them coming back either. There are some
> > > > supplies in there though that I think we would like to come back, n=
o?
> > > > Maybe this particular device doesn't have any supplies, but that do=
esn't
> > > > really seem credible.
> > >
> > > We will use Firmware-name in Device Tree.
> >
> > > For power supply settings, because there may be other device using
> > > same regulator.
> >
> > If there are other devices using the same regulator is it more
> > important that you document it so that it doesn't get disabled by the
> > other users.
> >
> > > We plan to define it as an optional property for user to control in
> > > next release.
> >
> > I don't see how the regulator would not be required, the device doesn't
> > function without power.
> >
> > Thanks,
> > Conor.
>=20
> I will set power supply as required.
> The description of power supply as below,
>=20
> properties:
>   vccd-supply:
>     description: A phandle for the regualtor supplying IO power. Should b=
e own
>                  by TPIC only.

What does "owned by TPIC" only mean? Why would the vccd supply not be
allowed to be shared with another device?

> This works for TP digital IO only, main power is
>                  given by display part VSP/VSN power source which is cont=
rolled
>                  by lcm driver.

What drivers control things doesn't really matter here, we're just
describing the hardware. If there's another supply to the controller,
then document it too please.

Thanks,
Conor.

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