Re: [PATCH v7 2/7] dt-bindings: iio: adc: microchip,mcp3564: Add spi-device-addr

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 25 Jul 2026 15:57:07 -0500
David Lechner <dlechner@baylibre.com> wrote:

> On 7/22/26 2:54 AM, Janani Sunil wrote:
> > Add the generic spi-device-addr property to the binding and deprecate
> > the existing vendor specific microchip,hw-device-address property.
> > 
> > Signed-off-by: Janani Sunil <janani.sunil@analog.com>
> > ---
> >  .../devicetree/bindings/iio/adc/microchip,mcp3564.yaml         | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
> > index 675319276197..de1ea289e7f5 100644
> > --- a/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
> > +++ b/Documentation/devicetree/bindings/iio/adc/microchip,mcp3564.yaml
> > @@ -80,6 +80,7 @@ properties:
> >      $ref: /schemas/types.yaml#/definitions/uint32
> >      minimum: 0
> >      maximum: 3
> > +    deprecated: true
> >      description:
> >        The address is set on a per-device basis by fuses in the factory,
> >        configured on request. If not requested, the fuses are set for 0x1.
> > @@ -91,6 +92,12 @@ properties:
> >        clocking of the device address (BITS[7:6] - top two bits of COMMAND BYTE
> >        which is first one on the wire).
> >  
> > +  spi-device-addr:
> > +    maxItems: 1  
> 
> Does it not make sense to all for more than once device connected
> to the same CS here? I would expect maxItems to be 4 to match the
> number of possible addresses.
> 

I think for this part their isn't a reason to aggregate.
No magic accesses that touch them all at once.  So this hits
exactly the point you raised about how we set the address for
more than one of them.

Jonathan

> > +    items:
> > +      enum: [0, 1, 2, 3]
> > +    default: [1]
> > +
> >    "#io-channel-cells":
> >      const: 1
> >  
> > @@ -123,7 +130,6 @@ dependencies:
> >  required:
> >    - compatible
> >    - reg
> > -  - microchip,hw-device-address
> >    - spi-max-frequency
> >  
> >  allOf:
> > @@ -159,7 +165,7 @@ examples:
> >              spi-cpha;
> >              spi-cpol;
> >              spi-max-frequency = <10000000>;
> > -            microchip,hw-device-address = <1>;
> > +            spi-device-addr = <1>;
> >  
> >              #address-cells = <1>;
> >              #size-cells = <0>;
> >   
>