Re: [PATCH v3 08/10] dt-bindings: iio: adc: ad7476: Add ROHM bd79105

[Matti Vaittinen]

On 09/08/2025 22:21, Jonathan Cameron wrote:
> On Fri, 8 Aug 2025 11:54:25 +0300
> Matti Vaittinen <mazziesaccount@xxxxxxxxx> wrote:
>
> > The ROHM BD79105 is a simple, 16-bit, 1-channel ADC with a 'CONVSTART'
> > pin used to start the ADC conversion. Other than the 'CONVSTART', there
> > are 3 supply pins (one used as a reference), analog inputs, ground and
> > communication pins. It's worth noting that the pin somewhat confusingly
> > labeled as 'DIN', is a pin which should be used as a chip-select. The IC
> > does not have any writable registers.
> >
> > The device is designed so that the output pin can, in addition to
> > outputting the data, be used as a 'data-ready'-IRQ. This, however, would
> > require the IRQ to be masked from host side for the duration of the data
> > reads - and it wouldn't also work when the SPI is shared. (As access to
> > the other SPI devices would cause data line changes to be detected as
> > IRQs - and the BD79105 provides no means to detect if it has generated
> > an IRQ).
> >
> > Hence the device-tree does not contain any IRQ properties.
>
> Commit message needs an update as it now allows for IRQ properties.

Ah, true. Thanks :)

> > Add a compatible for the bd79105.
> >
> > Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
> >
> > ---
> > Revision history:
> >   v2 => :
> >   - No changes
> >
> >   v1 => v2:
> >   - BD79105 can provide data-ready IRQ (or GPIO) via DOUT-pin.
> > ---
> >   .../bindings/iio/adc/adi,ad7476.yaml          | 54 +++++++++++++++++++
> >   1 file changed, 54 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7476.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7476.yaml
> > index d0cb32f136e5..c411a7467651 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7476.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7476.yaml
> > @@ -41,6 +41,7 @@ properties:
> >                 - adi,ad7910
> >                 - adi,ad7920
> >                 - adi,ad7940
> > +              - rohm,bd79105
> >                 - ti,adc081s
> >                 - ti,adc101s
> >                 - ti,adc121s
> > @@ -55,6 +56,11 @@ properties:
> >     reg:
> >       maxItems: 1
> >   
> > +  interrupts:
> > +    description:
> > +      The data-ready interrupt. Provided via DOUT pin.
> > +    maxItems: 1
> > +
> >     vcc-supply:
> >       description:
> >         Main powersupply voltage for the chips, sometimes referred to as VDD on
> > @@ -75,6 +81,10 @@ properties:
> >       description: A GPIO used to trigger the start of a conversion
> >       maxItems: 1
> >   
> > +  rdy-gpios:
> > +    description: A GPIO for detecting the data-ready.
> > +    maxItems: 1
> > +
> >   required:
> >     - compatible
> >     - reg
> > @@ -82,6 +92,20 @@ required:
> >   allOf:
> >     - $ref: /schemas/spi/spi-peripheral-props.yaml#
> >   
> > +# Devices with an IRQ
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - rohm,bd79105
> > +    then:
> > +      properties:
> > +        interrupts: true
>
> It's been a while since I wrote one of these, but do we need
> the true bit given we have already specified the interrupts
> property.  I think we only need to do the setting to false
> on an if: not:

I think you're right. I just used same approach that had already been 
used throughout this binding. I'll try dropping the 'true'-branches, but 
then also the other 'true'-branches should be dropped from the binding.

I'll just do that and send v4. Let's see what Rob/Krzk/Conor have to say :)

Yours,
	-- Matti