linux-kernel - Re: [PATCH 1/2] dt-bindings: input: touchscreen: goodix: Add no-reset-pull-up property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <23onpttl3w2wo3625c7flbljahojipsb4xznrx6xynr7rrzofr@2bcvjji7dpu6>
Date: Mon, 28 Apr 2025 12:30:47 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Esben Haabendal <esben@...nix.com>
Cc: Krzysztof Kozlowski <krzk@...nel.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Hans de Goede <hdegoede@...hat.com>, linux-input@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: input: touchscreen: goodix: Add
 no-reset-pull-up property

On Mon, Apr 28, 2025 at 07:58:55AM +0000, Esben Haabendal wrote:
> On Monday, April 28th, 2025 at 09:48, Krzysztof Kozlowski <krzk@...nel.org> wrote:
> > On Tue, Apr 22, 2025 at 05:15:02PM GMT, Esben Haabendal wrote:
> > 
> > > This should be added for boards where there is no pull-up on the reset pin,
> > > as the driver will otherwise switch the reset signal to high-impedance to
> > > save power, which obviously not safe without pull-up.
> > > 
> > > Signed-off-by: Esben Haabendal esben@...nix.com
> > > ---
> > > Documentation/devicetree/bindings/input/touchscreen/goodix.yaml | 4 ++++
> > > 1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
> > > index eb4992f708b70fef93bd4b59b9565123f7c6ad5d..7e5c4b98f2cb1ef61798252ea5c573068a46d4aa 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
> > > @@ -45,6 +45,10 @@ properties:
> > > reset-gpios:
> > > maxItems: 1
> > > 
> > > + no-reset-pull-up:
> > 
> > Is this common property? Where is it defined? Otherwise missing vendor
> > prefix.
> 
> Good question. When is something a common property?
> 
> The idea of marking something as not having a pull-up on the reset pin could be considered a common thing I guess.
> But for now, I am defining it for the goodix driver only, as I am only aware of these devices needing to handle it in a special way.
> 
> Should I rename it to goodix,no-reset-pull-up?

We already have GPIO_PULL_UP/GPIO_PULL_DOWN flags available in GPIO
bindings. So maybe the correct way is to have the driver rely on them
and only leave the reset line in high-impedance mode if GPIO tells it
that there is a pull-up?

Thanks.

-- 
Dmitry