Re: [PATCH v2 2/2] dt-bindings: iio: adc: ad7124: add config nodes

[Rob Herring <robh+dt@kernel.org>]

On Sat, Feb 6, 2021 at 9:26 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Thu, 4 Feb 2021 13:35:51 +0200
> <alexandru.tachici@analog.com> wrote:
>
> > From: Alexandru Tachici <alexandru.tachici@analog.com>
> >
> > Document use of configurations in device-tree bindings.
> >
> > Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
>
> Ignoring discussing in my reply to the cover letter...
>
> This is a breaking change as described.  We can't move properties
> around without some sort of fullback for them being in the old
> location.
>
> > ---
> >  .../bindings/iio/adc/adi,ad7124.yaml          | 72 +++++++++++++++----
> >  1 file changed, 57 insertions(+), 15 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
> > index fb3d0dae9bae..330064461d0a 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
> > @@ -62,20 +62,19 @@ required:
> >    - interrupts
> >
> >  patternProperties:
> > -  "^channel@([0-9]|1[0-5])$":
> > -    $ref: "adc.yaml"
> > +  "^config@(2[0-7])$":
> >      type: object
> >      description: |
> > -      Represents the external channels which are connected to the ADC.
> > +      Represents a channel configuration.
> > +      See Documentation/devicetree/bindings/iio/adc/adc.txt.
>
> adc.yaml now.
>
>
> >
> >      properties:
> >        reg:
> >          description: |
> > -          The channel number. It can have up to 8 channels on ad7124-4
> > -          and 16 channels on ad7124-8, numbered from 0 to 15.
> > +          The config number. It can have up to 8 configuration.
> >          items:
> > -          minimum: 0
> > -          maximum: 15
> > +         minimum: 20
> > +         maximum: 27
>
> Number then 0-7 please rather than 20-27.

That doesn't work. It would be creating 2 address spaces at one level
with channel@0 and config@0. The way to address this is add a
'configs' node with config@N children.

My question here though is where does 20-27 come from. I suspect it's
made up which isn't good either. Addresses should also be rooted in
something in the h/w.

Rob