linux-kernel - Re: [PATCH v9 1/7] dt-bindings: spmi: Add X1E80100 SPMI PMIC ARB schema

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Message-ID: <ZhkVPXCDySXRWWJj@linaro.org>
Date: Fri, 12 Apr 2024 14:04:29 +0300
From: Abel Vesa <abel.vesa@...aro.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Stephen Boyd <sboyd@...nel.org>,
	Matthias Brugger <matthias.bgg@...il.com>,
	Konrad Dybcio <konrad.dybcio@...aro.org>,
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Rob Herring <robh@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
	Srini Kandagatla <srinivas.kandagatla@...aro.org>,
	Johan Hovold <johan@...nel.org>,
	David Collins <quic_collinsd@...cinc.com>,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-arm-msm@...r.kernel.org, linux-mediatek@...ts.infradead.org,
	devicetree@...r.kernel.org
Subject: Re: [PATCH v9 1/7] dt-bindings: spmi: Add X1E80100 SPMI PMIC ARB
 schema

On 24-04-08 08:30:56, Krzysztof Kozlowski wrote:
> On 08/04/2024 08:04, Abel Vesa wrote:
> > On 24-04-07 19:07:03, Bjorn Andersson wrote:
> >> On Sun, Apr 07, 2024 at 07:23:21PM +0300, Abel Vesa wrote:
> >>> Add dedicated schema for X1E80100 PMIC ARB (v7) as it allows multiple
> >>> buses by declaring them as child nodes.
> >>>
> >>
> >> But is this really a "dedicated schema for X1E80100"? Isn't it "the
> >> schema for all multi-bus controllers"?
> >>
> >> I.e. isn't this a "dedicated schema for all platforms starting with
> >> SM8450"?
> > 
> > Suggestion was from Krzysztof to add platform specific comaptible (and
> > therefore schema). Since the first platform that will support in
> > upstream proper multi bus is the x1e80100, the schema needs to bear the
> > same name as the compatible. When support for multi bus will be added to
> > the other platforms (including the SM8450), they will use the fallback
> > compatible of the x1e80100 and will be documented in this newly added
> > schema. We did the same thing with some PHYs drivers, IIRC.
> > 
> >>
> >> Can you please use the commit message to document the actual reason why
> >> you choose to create a dedicated schema for this? Is it simply to avoid
> >> having to schema with either pmics or multiple buses as children?
> > 
> > I can re-send the patchset with such a phrase in commit message.
> > 
> > One of the early versions of this patchset was actually submitting a
> > generic compatible for multi bus, but I remember that there was a
> > request for following the platform dedicated approach.
> > 
> > Krzysztof, can you please provide here the argument for why that is
> > preferred?
> 
> I could not find such suggestions from my side in the archives, except:
> https://lore.kernel.org/all/dd86117e-0196-499b-b8b3-efe4013cbc07@linaro.org/
> 
> where I want SoC specific compatibles to be used, not versions.
> 
> Now about this binding, it is not a schema for all platforms starting
> with sm8450, but only for x1e. I do not understand why this would be a
> problem?
> 

I agree, I don't think there is a problem with that. At some point,
all platforms starting with sm8450 will be added and then we can even
make the sm8450 compatible as the fallback comaptible.

> If you ask why this is not a schema for all platforms, then because:
> 1. maybe no one tested other SoCs?
> 2. maybe no one cares?
> 3. maybe other boards need some quirks, so this would be applicable but
> not fully?
> 
> I don't know... since when do we add "generic schemas"?
> 

The focus of this patchset is support on X Elite which implicitly needs
multi bus support. Again, we can do the other ones later on. I don't
think we should extend the focus of this patchset more that it already
is.

> However maybe the question is different: why other devices are not
> described here, while they should? Then probably Abel can answer what he
> wants and what he does not want to describe. There is no requirement to
> model all possible hardware in a binding, but instead describe one
> hardware, so x1e, fully.
> 

I'll switch the older platforms as well in a separate patchset, I promise.
But let's not delay this any longer.

> Best regards,
> Krzysztof
>