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

[Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>]

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 ?

Best regards,
Ciprian