Re: [PATCH v2 1/7] dt-bindings: interrupt-controller: fsl,irqsteer: add S32N79 support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 05/03/2026 13:25, Ciprian Marian Costea wrote:
> On 3/5/2026 2:12 PM, Krzysztof Kozlowski wrote:
>> On 05/03/2026 13:02, Ciprian Marian Costea wrote:
>>> On 2/26/2026 9:31 AM, Krzysztof Kozlowski wrote:
>>>> On Wed, Feb 25, 2026 at 02:38:52PM +0100, Ciprian Costea wrote:
>>>>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>>>
>>>>> Add compatible string for the interrupt steering controller used in NXP
>>>>> S32N79 SoC.
>>>>>
>>>>> The S32N79 SoC differs from the i.MX version by not implementing the
>>>>> CHANCTRL register, but otherwise maintains the same programming model and
>>>>> register layout.
>>>>>
>>>>> Co-developed-by: Larisa Grigore <larisa.grigore@nxp.com>
>>>>> Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
>>>>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>>> ---
>>>>>    .../devicetree/bindings/interrupt-controller/fsl,irqsteer.yaml   | 1 +
>>>>>    1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/interrupt-controller/fsl,irqsteer.yaml b/Documentation/devicetree/bindings/interrupt-controller/fsl,irqsteer.yaml
>>>>> index 5c768c1e159c..caf3e4a1f26f 100644
>>>>> --- a/Documentation/devicetree/bindings/interrupt-controller/fsl,irqsteer.yaml
>>>>> +++ b/Documentation/devicetree/bindings/interrupt-controller/fsl,irqsteer.yaml
>>>>> @@ -22,6 +22,7 @@ properties:
>>>>>                  - fsl,imx94-irqsteer
>>>>>                  - fsl,imx95-irqsteer
>>>>>              - const: fsl,imx-irqsteer
>>>>> +      - const: nxp,s32n79-irqsteer
>>>>
>>>> So that should be part of enum with the first entry.
>>>>
>>>> Best regards,
>>>> Krzysztof
>>>>
>>>
>>> Hello Krzysztof,
>>>
>>> Thanks for your review. Regarding this change, I was thinking since
>>> S32N79 irqsteer does not implement the 'CHANCTRL' register, it should
>>> not fallback to 'fsl,imx-irqsteer'. If the driver were to match on the
>>> fallback compatible, it would attempt to write to the non-existent
>>> CHANCTRL register.
>>>
>>> Am I wrong?
>>
>> No clue, I did not say anything about fallbacks.
>>
>> Best regards,
>> Krzysztof
> 
> Indeed, but your suggestion of moving 'nxp,s32n79-irqsteer' under the
> enum would fallback on 'fsl,imx-irqsteer'.
> 
> Am I misunderstanding your suggestion ?

Open the code. What is the first entry?

Best regards,
Krzysztof