Re: [PATCH 1/4] dt-bindings: iio: adc: ad7768-1: add new supported parts

[Jonathan Santos <jonath4nns@gmail.com>]

On 08/13, Krzysztof Kozlowski wrote:
> On 13/08/2025 04:48, Jonathan Santos wrote:
> > Add compatibles for supported parts in the ad7768-1 family:
> > 	ADAQ7767-1, ADAQ7768-1 and ADAQ7769-1
> > 
> > Add property and checks for AFF gain, supported by ADAQ7767-1
> > and ADAQ7769-1 parts:
> > 	adi,aaf-gain
> > 
> > Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
> > ---
> >  .../bindings/iio/adc/adi,ad7768-1.yaml        | 48 +++++++++++++++++--
> >  1 file changed, 44 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
> > index c06d0fc791d3..568a85e0d052 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
> > @@ -4,18 +4,26 @@
> >  $id: http://devicetree.org/schemas/iio/adc/adi,ad7768-1.yaml#
> >  $schema: http://devicetree.org/meta-schemas/core.yaml#
> >  
> > -title: Analog Devices AD7768-1 ADC device driver
> > +title: Analog Devices AD7768-1 ADC family device driver
> 
> If doing this, drop device driver. It should not be here in the first place.
> 

Noted.

> >  
> >  maintainers:
> >    - Michael Hennerich <michael.hennerich@analog.com>
> >  
> >  description: |
> > -  Datasheet at:
> > -    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-1.pdf
> > +  Analog Devices AD7768-1 24-Bit Single Channel Low Power sigma-delta ADC family
> > +
> > +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7768-1.pdf
> > +  https://www.analog.com/media/en/technical-documentation/data-sheets/adaq7767-1.pdf
> > +  https://www.analog.com/media/en/technical-documentation/data-sheets/adaq7768-1.pdf
> > +  https://www.analog.com/media/en/technical-documentation/data-sheets/adaq7769-1.pdf
> >  
> >  properties:
> >    compatible:
> > -    const: adi,ad7768-1
> > +    enum:
> > +      - adi,ad7768-1
> > +      - adi,adaq7767-1
> > +      - adi,adaq7768-1
> > +      - adi,adaq7769-1
> >  
> >    reg:
> >      maxItems: 1
> > @@ -58,6 +66,23 @@ properties:
> >      description:
> >        ADC reference voltage supply
> >  
> > +  adi,aaf-gain:
> > +    description: |
> > +      Specifies the gain of the Analog Anti-Aliasing Filter (AAF) applied to the
> > +      ADC input, measured in milli-units. The AAF provides additional signal
> 
> What is milli unit? Isn't gain in dB, so maybe you want mB? Quite
> unpopular to see mB, but we cannot use 1/100 of dB, so I could
> understand it.
>

Actually, the gain is expressed in V/V, not in dB. I may have phrased it poorly, but since
there are fractional values like 0.364 and 0.143, I chose to represent it
in milli-units.

> > +      rejection within the frequency range of fs ± f3dB, where fs is the sampling
> > +      frequency, and f3dB is the -3dB cutoff frequency. The specific values of
> > +      fs and f3dB, as well as the rejection intensity, depend on the digital
> > +      filter configuration.
> Best regards,
> Krzysztof