Re: [PATCH v2 02/11] dt-bindings: hwmon: Add Apple System Management Controller hwmon schema

[Guenter Roeck]

On 9/27/25 17:36, James Calligeros wrote:
> Hi Rob,
>
> On Friday, 26 September 2025 7:43:23 am Australian Eastern Standard Time Rob
> Herring wrote:
> > On Thu, Sep 25, 2025 at 3:49 PM Janne Grunau <j@xxxxxxxxxx> wrote:
> > > On Fri, Aug 29, 2025 at 11:40:57AM -0500, Rob Herring wrote:
> > > > This should be something like this:
> > > >
> > > > "^current-[A-Za-z0-9]{4}$":
> > > >    $ref: "#/$defs/sensor"
> > > >    unevaluatedProperties: false
> > > >
> > > > With the $defs/sensor being:
> > > >
> > > > $defs:
> > > >    sensor:
> > > >      type: object
> > > >      
> > > >      properties:
> > > >        apple,key-id:
> > > >          $ref: /schemas/types.yaml#/definitions/string
> > > >          pattern: "^[A-Za-z0-9]{4}$"
> > > >          
> > > >          description:
> > > >            The SMC FourCC key of the desired sensor. Must match the
> > > >            node's suffix.
> > > >        
> > > >        label:
> > > >          description: Human-readable name for the sensor
> > > >      
> > > >      required:
> > > >        - apple,key-id
> > > >        - label
> > > >
> > > > Though in general, 'label' should never be required being just for human
> > > > convenience.
> > >
> > > That does not sound as it would be compatible with skipping nodes in the
> > > driver if the node misses label. The driver could of course fall back
> > > to create a hwmon sensors without labels.
> >
> > The driver absolutely should.
>
> The original submission (and our downstream version) do this, but I changed
> it for v2 per Sven's feedback [1]. Outside of development/experimentation,
> we will (should) never have a sensor in the Devicetree of uknown utility.
> If we know what a sensor is for, then we should have a label for it.

Label attributes are optional in hwmon drivers. Period.

Guenter