Re: [PATCH v1 5/7] arm: dts: qcom: mdm9615: remove invalid pmic subnodes compatibles

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

On 29/09/2022 14:48, Neil Armstrong wrote:
> Hi,
> 
> On 29/09/2022 14:27, Krzysztof Kozlowski wrote:
>>
>> We are making circles and discussion takes too much. 
> 
> I'm sorry this happens, but I really want solve this stuff which in suspend since 2015.
> 
> So let me recall the original issue:
> 
> DTBS check reports:
> 
> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dtb: pmic@0: compatible: ['qcom,pm8018', 'qcom,pm8921'] is too long
>          From schema: Documentation/devicetree/bindings/mfd/qcom-pm8xxx.yaml
> 
> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dtb: pmic@0: rtc@11d:compatible: ['qcom,pm8018-rtc', 'qcom,pm8921-rtc'] is too long
>          From schema: Documentation/devicetree/bindings/mfd/qcom-pm8xxx.yaml
> 
> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dtb:0:0: /soc/qcom,ssbi@500000/pmic@0/pwrkey@1c: failed to match any schema with compatible: ['qcom,pm8018-pwrkey', 'qcom,pm8921-pwrkey']
> 
> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dtb:0:0: /soc/qcom,ssbi@500000/pmic@0/pwrkey@1c: failed to match any schema with compatible: ['qcom,pm8018-pwrkey', 'qcom,pm8921-pwrkey']
> 
> arch/arm/boot/dts/qcom-mdm9615-wp8548-mangoh-green.dtb: rtc@11d: compatible: ['qcom,pm8018-rtc', 'qcom,pm8921-rtc'] is too long
>          From schema: Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
> 
> So trying to solve those, and since the PMIC in the wp8548 module is a PM8018, and it happens to be (partially ?? potentially ??) compatible
> with the PM8921, and I had issues adding per-HW compatible for the pwrkey, the obvious solution would be to
> drop the PM8921 compatibility since it's only probable and nothing proves it's right.

Although it is obvious solution it is also affecting all out-of-tree
users of DTS.

> 
> But what's sure: it's a PM8018 PMIC.

I could not find the spec for both of these, but similar numbers have
for example exactly the same RTC. I guess other blocks are also the same.

> 
> But since the PM8018 PWRKEY interface is compatible with the PM8921 PWRKEY interface,
> it's perfectly ok to the the MP8921 compatible here.
> 
> OK, so as you quoted multiple times:
> "How this should be fixed? First, drop bogus entries from drivers, then
> document proper compatibles."
> 
> OK so there's no bogus entries to remove here, and the only compatible to
> potentially document is the pm8018-pwrkey but it seems to be wrong.

All the entries in drivers which are duplicating the fallback are not
needed. I called them bogus because adding them brought no meaning.

> I'll be happy to have an hint on how to handle that to I can go forward and
> stop the noise, there's still plenty of stuff to fix in the MDM9615 DT.

Drop the unneeded entries from the driver, document (properly) the
compatible how it is used in DTS (so not in some other way than DTS
expresses it).

Best regards,
Krzysztof