Re: [PATCH v2 3/4] dt-bindings: iio: adc: ad4080: add AD4880 support

["Nuno Sá" <noname.nuno@gmail.com>]

On Sat, 2026-02-07 at 11:41 +0100, Krzysztof Kozlowski wrote:
> On Fri, Feb 06, 2026 at 06:07:15PM +0200, Antoniu Miclaus wrote:
> > Add support for the AD4880, a dual-channel 20-bit 40MSPS SAR ADC
> > with integrated fully differential amplifiers (FDA).
> > 
> > The AD4880 has two independent ADC channels, each with its own SPI
> > configuration interface. This requires:
> > - Two entries in reg property for primary and secondary channel chip selects
> 
> Please wrap commit message according to Linux coding style / submission
> process (neither too early nor over the limit):
> https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597
> 
> Please run scripts/checkpatch.pl on the patches and fix reported
> warnings.
> 
> > - Two io-backends entries for the two data channels
> > 
> > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
> > ---
> > Changes in v2:
> >   - Replace custom adi,aux-spi-cs property with standard reg property
> >     containing two entries for multi-channel devices
> >   - Add conditional schema validation for reg and io-backends based on
> >     compatible string
> >   - Update example to use reg = <0 1> instead of adi,aux-spi-cs
> >   - Add AD4880 datasheet link
> > 
> >  .../bindings/iio/adc/adi,ad4080.yaml          | 51 ++++++++++++++++++-
> >  1 file changed, 49 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4080.yaml
> > b/Documentation/devicetree/bindings/iio/adc/adi,ad4080.yaml
> > index ccd6a0ac1539..7108a91bb0bf 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad4080.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4080.yaml
> > @@ -18,7 +18,11 @@ description: |
> >    service a wide variety of precision, wide bandwidth data acquisition
> >    applications.
> >  
> > +  The AD4880 is a dual-channel variant with two independent ADC channels,
> > +  each with its own SPI configuration interface.
> > +
> >    https://www.analog.com/media/en/technical-documentation/data-sheets/ad4080.pdf
> > +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4880.pdf
> >  
> >  $ref: /schemas/spi/spi-peripheral-props.yaml#
> >  
> > @@ -31,9 +35,15 @@ properties:
> >        - adi,ad4084
> >        - adi,ad4086
> >        - adi,ad4087
> > +      - adi,ad4880
> >  
> >    reg:
> > -    maxItems: 1
> > +    minItems: 1
> > +    maxItems: 2
> > +    description:
> > +      SPI chip select(s). For single-channel devices, one chip select.
> > +      For multi-channel devices like AD4880, two chip selects are required
> > +      as each channel has its own SPI configuration interface.
> >  
> >    spi-max-frequency:
> >      description: Configuration of the SPI bus.
> > @@ -57,7 +67,8 @@ properties:
> >    vrefin-supply: true
> >  
> >    io-backends:
> > -    maxItems: 1
> > +    minItems: 1
> > +    maxItems: 2
> 
> Instead list the items with minItems, so the order is defined.
> 

Also looks like we now need 'io-backend-names'.

- Nuno Sá

> >