Re: [PATCH 1/2] dt-bindings: iio: adc: rtq6056: add support for the whole RTQ6056 family

ChiYuan Huang
2023-12-28T08:44:53Z

Hi, Krzysztof:
On Thu, Dec 28, 2023 at 09:06:30AM +0100, Krzysztof Kozlowski wrote:
> On 28/12/2023 08:58, ChiYuan Huang wrote:
> > On Thu, Dec 28, 2023 at 08:09:35AM +0100, Krzysztof Kozlowski wrote:
> >> On 28/12/2023 04:19, ChiYuan Huang wrote:
> >>> On Tue, Dec 26, 2023 at 01:12:50PM +0100, Krzysztof Kozlowski wrote:
> >>>> On 26/12/2023 12:19, ChiYuan Huang wrote:
> >>>>> On Tue, Dec 26, 2023 at 10:18:47AM +0100, Krzysztof Kozlowski wrote:
> >>>>>> On 26/12/2023 04:47, cy_huang@richtek.com wrote:
> >>>>>>> From: ChiYuan Huang <cy_huang@richtek.com>
> >>>>>>>
> >>>>>>> Add compatible support for RTQ6053 and RTQ6059.
> >>>>>>>
> >>>>>>> Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> >>>>>>> ---
> >>>>>>> .../devicetree/bindings/iio/adc/richtek,rtq6056.yaml | 5 ++++-
> >>>>>>> 1 file changed, 4 insertions(+), 1 deletion(-)
> >>>>>>>
> >>>>>>> diff --git a/Documentation/devicetree/bindings/iio/adc/richtek,rtq6056.yaml b/Documentation/devicetree/bindings/iio/adc/richtek,rtq6056.yaml
> >>>>>>> index 88e008629ea8..d1e1f36d1972 100644
> >>>>>>> --- a/Documentation/devicetree/bindings/iio/adc/richtek,rtq6056.yaml
> >>>>>>> +++ b/Documentation/devicetree/bindings/iio/adc/richtek,rtq6056.yaml
> >>>>>>> @@ -25,7 +25,10 @@ description: |
> >>>>>>>
> >>>>>>> properties:
> >>>>>>> compatible:
> >>>>>>> - const: richtek,rtq6056
> >>>>>>> + enum:
> >>>>>>> + - richtek,rtq6053
> >>>>>>> + - richtek,rtq6056
> >>>>>>
> >>>>>> Aren't these devices compatible? Your driver change says they are, so
> >>>>>> express compatibility with list here (and oneOf).
> >>>>>>
> >>>>> Thanks, I try to take other binding as the reference. One more question.
> >>>>> If rtq6053 is compatible with rtq6056, there's only chip package type difference.
> >>>>> Do I need to seperate it into a dedicated enum element?
> >>>>> Or just put it into one item and said this part number is compatible with rtq6056?
> >>>>
> >>>> See example-schema. You need enum and items, both in oneOf:.
> >>>>
> >>> After reading the 'example-schema', I Still cannot understand what the special case items
> >>> means.
> >>
> >> What is "special case items"?
> >>
> > I may misunderstand something. The special case is the 'fallback' that you mentaioned in
> > the last.
> >>>
> >>> But in my case, is the below change correct?
> >>> [Diff]
> >>> properties:
> >>> compatible:
> >>> - enum:
> >>> - - richtek,rtq6053
> >>> - - richtek,rtq6056
> >>> - - richtek,rtq6059
> >>> + oneOf:
> >>> + - items:
> >>> + - enum:
> >>> + - richtek,rtq6053
> >>> + - richtek,rtq6056
> >>> + - richtek,rtq6059
> >>
> >> This changes nothing, you still have just one item. The example-schema
> >> has exactly that case, so why you are coding it differently?
> >>
> >> Anyway, test your DTS with the fallback, you will see that above does
> >> not work.
> >>
> > I rewrite the below one and tested. it seems correct.
> >
> > [Diff]
> > compatible:
> > - enum:
> > - - richtek,rtq6053
> > - - richtek,rtq6056
> > - - richtek,rtq6059
> > + oneOf:
> > + - enum:
> > + - richtek,rtq6053
> > + - richtek,rtq6059
> > + - items:
> > + - const: richtek,rtq6056
>
> You still need two items here to express compatibility. What is
> compatible with what? It must be rtq6053 compatible with rtq6056,
> because you cannot break the ABI, can you?
>
> >
> > Just one more question. If rtq6053 is fully compatibie with rtq6056, does it need to be put
> > into oneOf enum or be just put into items enum and use the 'fallback' mechanism?
>
> The fallback is just a term. The point is to have a list of two
> compatibles. See: Devicetree specification, writing-bindings and
> numerous presentations about writing DTS.
>
> >
> > If so, the 'richtek,rtq6053' in of_device_id match can be removed. Though it just remove
> > one line, but less-changed would be better.
>
> The device using fallback should be removed the driver of_device_id, so
> 6053 goes away.
>
Thanks for all the information. If not misunderstanding, I'll remove "dt match id" for 6053.

And the binding fix in v2 will be
properties:
compatible:
- enum:
- - richtek,rtq6053
- - richtek,rtq6056
- - richtek,rtq6059
+ oneOf:
+ - enum:
+ - richtek,rtq6056
+ - richtek,rtq6059
+ - items:
+ - enum:
+ - richtek,rtq6053
+ - const: richtek,rtq6056

This make the 6053 compatible with 6056 with DT fallback.

> Best regards,
> Krzysztof
>