Re: [PATCH 1/2] dt-bindings: iio: dac: add support for mcp47a1

[David Lechner]

On 7/25/26 3:12 AM, Joshua Crofts wrote:
> On Sat, 25 Jul 2026 00:04:51 +0100
> Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> 
>> On Tue, 21 Jul 2026 20:24:38 +0200
>> Joshua Crofts <joshua.crofts1@xxxxxxxxx> wrote:
>>
>>> The Microchip MCP47A1 is a 6-bit volatile Digital-to-Analog converted
>>> which communicates via I2C.
>>>
>>> Signed-off-by: Joshua Crofts <joshua.crofts1@xxxxxxxxx>
>>> ---
>>>  .../bindings/iio/dac/microchip,mcp47a1.yaml        | 56 ++++++++++++++++++++++
>>>  MAINTAINERS                                        |  6 +++
>>>  2 files changed, 62 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp47a1.yaml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47a1.yaml
>>> new file mode 100644
>>> index 000000000000..3322fca03b3a
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp47a1.yaml  
>>
>>> +
>>> +examples:
>>> +  - |
>>> +    i2c {
>>> +          #address-cells = <1>;
>>> +          #size-cells = <0>;
>>> +
>>> +          dac@2e {
>>> +              compatible = "microchip,mcp47a1";
>>> +              reg = <0x2e>;
>>> +              vref-supply = <&vref_regulator>;
>>> +              vdd-supply = <&vdd_regulator>;
>>> +          };
>>> +
>>> +          dac@3e {
>>> +              compatible = "microchip,mcp47a1";  
>> Hi Joshua,
>>
>> What is the advantage of the second example?  I'd drop it.
>>
> 
> Hi Jonathan,
> 
> Per the datasheet, the MCP47A1 can have two different I2C slave
> addresses (0x2e and 0x3e), which allows two DACs to share the
> same bus, something I thought would be good to illustrate in the
> example.
> 

I know we haven't done this much historically, but we could make
that more obvious with this instead:

  reg:
    items:
      - enum: [0x2e, 0x3e]

Then the bindings validator would actually check for a valid
address.