Re: [PATCH net-next v2 1/3] dt-bindings: sram: qcom,imem: Allow modem-tables

[Krzysztof Kozlowski <krzk@kernel.org>]

On 14/07/2025 19:53, Konrad Dybcio wrote:
> On 5/27/25 1:42 PM, Krzysztof Kozlowski wrote:
>> On 27/05/2025 13:36, Konrad Dybcio wrote:
>>>>> diff --git a/Documentation/devicetree/bindings/sram/qcom,imem.yaml b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>> index 2711f90d9664b70fcd1e2f7e2dfd3386ed5c1952..7c882819222dc04190db357ac6f9a3a35137cc9e 100644
>>>>> --- a/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>> +++ b/Documentation/devicetree/bindings/sram/qcom,imem.yaml
>>>>> @@ -51,6 +51,9 @@ properties:
>>>>>      $ref: /schemas/power/reset/syscon-reboot-mode.yaml#
>>>>>  
>>>>>  patternProperties:
>>>>> +  "^modem-tables@[0-9a-f]+$":
>>>>> +    description: Region reserved for the IP Accelerator
>>>>
>>>> Missing additionalProperties: false, which would point you that this is
>>>> incomplete (or useless because empty).
>>>
>>> How do I describe a 'stupid' node that is just a reg?
>> With "reg" - similarly to many syscon bindings.
> 
> Is this sort of inline style acceptable, or should I introduce
> a separate file?

It's fine, assuming that it is desired in general. We do not describe
individual memory regions of syscon nodes and this is a syscon.

If this is NVMEM (which it looks like), then could use NVMEM bindings to
describe its cells - individual regions. But otherwise we just don't.

There are many exceptions in other platforms, mostly old or even
unreviewed by DT maintainers, so they are not a recommended example.

This would need serious justification WHY you need to describe the
child. Why phandle to the main node is not enough for consumers.

If the reason is - to instantiate child device driver - then as well no.
This has been NAKed on the lists many times - you need resources if the
child should be a separate node. Address space is one resource but not
enough, because it can easily be obtained from the parent/main node.



Best regards,
Krzysztof