Re: [PATCH] dt-bindings: pwm: imx: document i.MX compatibles

From: Thierry Reding <thierry.reding@gmail.com>
To: Krzysztof Kozlowski <krzk@kernel.org>, Rob Herring <robh+dt@kernel.org>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	linux-pwm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dt-bindings: pwm: imx: document i.MX compatibles
Date: Fri, 9 Oct 2020 14:02:39 +0200	[thread overview]
Message-ID: <20201009120239.GA450876@ulmo> (raw)
In-Reply-To: <20200926134157.GA4730@kozik-lap>

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On Sat, Sep 26, 2020 at 03:41:57PM +0200, Krzysztof Kozlowski wrote:
> On Sat, Sep 26, 2020 at 03:22:17PM +0200, Uwe Kleine-König wrote:
> > On Fri, Sep 25, 2020 at 11:26:09PM +0200, Krzysztof Kozlowski wrote:
> > > Document all ARMv5, ARMv6 and ARMv7 i.MX compatibles to fix dtbs_check
> > > warnings like:
> > > 
> > >   arch/arm/boot/dts/imx6dl-colibri-eval-v3.dt.yaml: pwm@2080000: compatible:0:
> > >     'fsl,imx6q-pwm' is not one of ['fsl,imx8mm-pwm', 'fsl,imx8mn-pwm', 'fsl,imx8mp-pwm', 'fsl,imx8mq-pwm']
> > > 
> > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > > ---
> > >  Documentation/devicetree/bindings/pwm/imx-pwm.yaml | 11 +++++++++++
> > >  1 file changed, 11 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.yaml b/Documentation/devicetree/bindings/pwm/imx-pwm.yaml
> > > index 473863eb67e5..379d693889f6 100644
> > > --- a/Documentation/devicetree/bindings/pwm/imx-pwm.yaml
> > > +++ b/Documentation/devicetree/bindings/pwm/imx-pwm.yaml
> > > @@ -25,6 +25,17 @@ properties:
> > >            - fsl,imx27-pwm
> > >        - items:
> > >            - enum:
> > > +              - fsl,imx25-pwm
> > 
> > The driver actually used fsl,imx27-pwm to bind ...
> 
> Yes, most of i.MX drivers use only few compatibles but DTSes and
> bindings use multiple of them.  I was convinced during various talks
> that the specific compatibles (so "fsl,imx6q-pwm, fsl,imx27-pwm") are
> preferred than generic ones (so only "fsl,imx27-pwm"). NXP took it
> to the another level creating compatibles for absolutely every flavor of
> their CPU. And they mainlined it in DTSes...
> 
> The PWM is this crazy examples where, as you say, only two compatibles
> are actually used for binding but DTSes uses more.

Yeah, these new compatible strings all seem to be used in the kernel, so
we might as well document them.

That said, I did want to apply this patch, but that fails. Am I missing
some other patch that you have sent out that touches this file? Actually
it looks like this is because you've based this patch on linux-next, or
perhaps the devicetree tree, because that contains commit d058717bdff4
("dt-bindings: pwm: imx-pwm: Add i.MX 8M compatibles") from you that
adds a couple more compatible strings. Probably best for Rob to pick
this up, then:

Acked-by: Thierry Reding <treding@nvidia.com>

Rob, here's a patchwork link for you if you need one:

	https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20200925212609.23093-1-krzk@kernel.org/

Although, looking at the devicetree-bindings instance version of that
patch, I see that it's got a failing check attached (which looks like
it can be ignored) and it's marked "Changes Requested", but no comments
saying so.

Not sure if you want anything done here?

Thierry

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