linux-kernel - Re: [PATCH v2 1/2] dt-bindings: iio: max30100: Add pulse-width 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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <CAHc1_P7W0sU_5dU8Ei9MgGOFA+N7Q=fotk91vdcGUuUGLWLuqg@mail.gmail.com>
Date: Sun, 12 Oct 2025 23:11:55 +0530
From: Shrikant <raskar.shree97@...il.com>
To: David Lechner <dlechner@...libre.com>
Cc: jic23@...nel.org, robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org, 
	nuno.sa@...log.com, andy@...nel.org, matt@...ostay.sg, 
	skhan@...uxfoundation.org, david.hunter.linux@...il.com, 
	linux-iio@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-kernel-mentees@...ts.linux.dev
Subject: Re: [PATCH v2 1/2] dt-bindings: iio: max30100: Add pulse-width property

On Fri, Oct 10, 2025 at 11:19 PM David Lechner <dlechner@...libre.com> wrote:
>
> On 10/7/25 10:17 PM, Shrikant Raskar wrote:
> > The appropriate LED pulse width for the MAX30100 depends on
> > board-specific optical and mechanical design (lens, enclosure,
> > LED-to-sensor distance) and the trade-off between measurement
> > resolution and power consumption. Encoding it in Device Tree
> > documents these platform choices and ensures consistent behavior.
> >
> > Tested on: Raspberry Pi 3B + MAX30100 breakout board.
> >
> > Signed-off-by: Shrikant Raskar <raskar.shree97@...il.com>
> >
> > Changes since v1:
> > Add unit suffix.
> > Drop redundant description.
> >
> > Link to v1:
> > https://lore.kernel.org/all/20251004015623.7019-2-raskar.shree97@gmail.com/
> > ---
> >  .../devicetree/bindings/iio/health/maxim,max30100.yaml      | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml b/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml
> > index 967778fb0ce8..5c651a0151cc 100644
> > --- a/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml
> > +++ b/Documentation/devicetree/bindings/iio/health/maxim,max30100.yaml
> > @@ -27,6 +27,11 @@ properties:
> >        LED current whilst the engine is running. First indexed value is
> >        the configuration for the RED LED, and second value is for the IR LED.
> >
> > +  maxim,pulse-width-us:
> > +    maxItems: 1
> > +    description: Pulse width in microseconds
>
> Would be nice to add to the description which pulse width this is referring to.
Thanks for your review comment, I have updated the description and
shared v3 patch for your review.
> > +    enum: [200, 400, 800, 1600]
>
> Properties with standard unit suffixes are u32 arrays, so I think this
> would fix the error and also make maxItems not necessary.
>
>        items:
>          - enum: [200, 400, 800, 1600]
>
Thanks for sharing the fix. I have tried it but 'dt_binding_check'
complains as below: 'items' is not one of ['description', 'deprecated',
'const', 'enum','minimum', 'maximum', 'multipleOf', 'default', '$ref', 'oneOf'].
Schema expects it to be defined as a single u32, not an array. I have
updated the patch accordingly.
> And we want to know what the default is if this property is omitted.
>
>         default: 1600
>
Thanks for your feedback, I have added the default value and shared v3
patch for your review.

Thanks and Regards,
Shrikant
> > +
> >  additionalProperties: false
> >
> >  required:
> > @@ -44,6 +49,7 @@ examples:
> >              compatible = "maxim,max30100";
> >              reg = <0x57>;
> >              maxim,led-current-microamp = <24000 50000>;
> > +            maxim,pulse-width-us = <1600>;
> >              interrupt-parent = <&gpio1>;
> >              interrupts = <16 2>;
> >          };
>