Re: [PATCH v4] dt-bindings: iio: afe: voltage-divider: Add io-channel-cells

From: Jonathan Cameron
Date: Sat Feb 10 2024 - 11:47:04 EST


On Tue, 6 Feb 2024 15:22:29 +0000
Conor Dooley <conor@xxxxxxxxxx> wrote:

> On Tue, Feb 06, 2024 at 04:25:01PM +0530, Naresh Solanki wrote:
> > Enable the voltage divider to both receive and provide measurement
> > services by adding #io-channel-cells.
> >
> > This is especially valuable in scenarios where an ADC has an analog
> > frontend, like a voltage divider, and obtaining its raw value isn't
> > interesting. It is desired to get the real voltage before the voltage
> > divider.
> >
> > Signed-off-by: Naresh Solanki <naresh.solanki@xxxxxxxxxxxxx>
>
> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>
> Thanks for adding the example. I have one comment about the wording, cos
> the last sentence doesn't really make sense without something referring
> back to the scenario you describe.
>
> > ---
> > .../devicetree/bindings/iio/afe/voltage-divider.yaml | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/afe/voltage-divider.yaml b/Documentation/devicetree/bindings/iio/afe/voltage-divider.yaml
> > index dddf97b50549..fd3c511e1beb 100644
> > --- a/Documentation/devicetree/bindings/iio/afe/voltage-divider.yaml
> > +++ b/Documentation/devicetree/bindings/iio/afe/voltage-divider.yaml
> > @@ -39,6 +39,17 @@ properties:
> > description: |
> > Channel node of a voltage io-channel.
> >
> > + '#io-channel-cells':
> > + description:
> > + In addition to consuming the measurement services of a voltage
> > + output channel, the voltage divider can act as a provider of
> > + measurement services to other devices. This is particularly
> > + useful in scenarios wherein an ADC has an analog frontend,
> > + such as a voltage divider, and then consuming its raw value
> > + isn't interesting.
>
> > It is desired to get the real voltage
> > + before the voltage divider.
>
> "In this case, the voltage before the divider is desired".
>
> Perhaps Jonathan can make that change, provided you are okay with it.
I've made the change and applied this patch. Given it will only initially
be pushed out for 0-day to take a look at it, feel free to shout if you'd
prefer different wording from Conor's suggestion.

Thanks,

Jonathan

>
> Cheers,
> Conor.
>
> > + const: 1
> > +
> > output-ohms:
> > description:
> > Resistance Rout over which the output voltage is measured. See full-ohms.
> >
> > base-commit: 99bd3cb0d12e85d5114425353552121ec8f93adc
> > --
> > 2.42.0
> >