Re: [PATCH v2 00/22] arm64: dts: qcom: remove duplication in PMIC declarations

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 03/04/2023 12:44, Konrad Dybcio wrote:
> 
> 
> On 2.04.2023 11:55, Krzysztof Kozlowski wrote:
>> On 02/04/2023 00:07, Dmitry Baryshkov wrote:
>>> The sc8280xp platform uses its own copy of PMIC declarations. This can
>>> easily end up with the issues that are fixed in the main PMIC include
>>> file, but are not fixed for sc8280xp (and vice versa). For example
>>> commit c0ee8e0ba5cc ("arm64: dts: qcom: pmk8350: Use the correct PON
>>> compatible") changed pmk8350 to use "qcom,pmk8350-pon" compat for the
>>> PON device, while sc8280xp-pmic.dtsi still has the incorrect
>>> "qcom,pm8998-pon".
>>>
>>> Another example is pm8280_2_temp_alarm device, which uses interrupts
>>> tied to SID 2, while having SID 3. This can be easily left unnoticed.
>>>
>>> Employ a small amount of C preprocessor magic to make
>>> sc8280xp-pmics.dtsi use standard PMIC include files
>>
>> Preprocessor magic is disliked in DTS. We allow only simple defines, no
>> undefs. Sometimes some nodes or strings could be concatenated, but in
>> obvious way. You should not parametrize it and have different, generated
>> labels in DTS based on something coming external to that DTS.
> This again begs the question, is it time we start moving parts of the
> dts code to be autogenerated?

Do we auto-generate C-code? Just a bit, but in general no. There are
exceptions but coding style is here clear:
https://elixir.bootlin.com/linux/v6.1-rc2/source/Documentation/process/coding-style.rst#L828

Pre-processor generated code should be narrowed to some cases or simpler
structures.

For DTS we actually are even stricter.


Best regards,
Krzysztof