Re: [PATCH v4 1/2] dt-bindings: iio: light: vcnl4000: add Capella CM36686 and CM36672P

[Erikas Bitovtas <xerikasxx@gmail.com>]

On 2/16/26 9:27 AM, Krzysztof Kozlowski wrote:
> On 15/02/2026 17:16, Erikas Bitovtas wrote:
>>> But CM36686 is fully compatible with CM36672P, right?
>>>
>>> So this would make sense?
>>>
>>>       - items:
>>>           - const: capella,cm36686
>>>           - const: vishay,vcnl4040
>>>           - const: capella,cm36686p
>>>
>>>
>> If you try to use CM36686 compatible for CM36672P, proximity channels
>> will work, but in_illuminance_raw will return 0 and changing illuminance
>> parameters will have no effect. That is because CM36672P is a proximity
>> sensor only and the register fields for ambient light are reserved.
>> And if you try to use CM36672P compatible with CM36686, it will work,
>> but only proximity channel will be available, even though CM36686 also
>> can sense light.
> 
> So clearly CM36672P is the superset and should be used with CM36686
> fallback.
> 
> Lack of the fallback how the patch is written now is a mistake.
> 

Is it not the other way around? CM36686 compatible fully supports
CM36672P, but CM36672P does not fully support CM36686. This would make
CM36672P a subset of CM36686, because CM36672P is the proximity sensor,
and CM36686 is proximity and ambient light sensor, and therefore, a
superset of CM36672P.