RE: [EXT] Re: [PATCH v3 1/4] dt-bindings: soc: imx8m: add DT Binding doc for soc unique ID

[Alice Guo <alice.guo@nxp.com>]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@kernel.org>
> Sent: 2020年11月17日 15:36
> To: Alice Guo <alice.guo@nxp.com>
> Cc: robh+dt@kernel.org; shawnguo@kernel.org; s.hauer@pengutronix.de;
> dl-linux-imx <linux-imx@nxp.com>; Peng Fan <peng.fan@nxp.com>;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org
> Subject: Re: [EXT] Re: [PATCH v3 1/4] dt-bindings: soc: imx8m: add DT Binding
> doc for soc unique ID
> 
> Caution: EXT Email
> 
> On Tue, Nov 17, 2020 at 07:10:28AM +0000, Alice Guo wrote:
> >
> >
> > > -----Original Message-----
> > > From: Krzysztof Kozlowski <krzk@kernel.org>
> > > Sent: 2020年11月17日 0:03
> > > To: Alice Guo <alice.guo@nxp.com>
> > > Cc: robh+dt@kernel.org; shawnguo@kernel.org; s.hauer@pengutronix.de;
> > > dl-linux-imx <linux-imx@nxp.com>; Peng Fan <peng.fan@nxp.com>;
> > > devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
> > > linux-arm-kernel@lists.infradead.org
> > > Subject: Re: [EXT] Re: [PATCH v3 1/4] dt-bindings: soc: imx8m: add
> > > DT Binding doc for soc unique ID
> > >
> > > Caution: EXT Email
> > >
> > > On Mon, Nov 16, 2020 at 07:04:13AM +0000, Alice Guo wrote:
> > > >
> > > > > -----Original Message-----
> > > > > From: Krzysztof Kozlowski <krzk@kernel.org>
> > > > > Sent: 2020年11月15日 0:50
> > > > > To: Alice Guo <alice.guo@nxp.com>
> > > > > Cc: robh+dt@kernel.org; shawnguo@kernel.org;
> > > > > s.hauer@pengutronix.de; dl-linux-imx <linux-imx@nxp.com>; Peng
> > > > > Fan <peng.fan@nxp.com>; devicetree@vger.kernel.org;
> > > > > linux-kernel@vger.kernel.org;
> > > > > linux-arm-kernel@lists.infradead.org
> > > > > Subject: [EXT] Re: [PATCH v3 1/4] dt-bindings: soc: imx8m: add
> > > > > DT Binding doc for soc unique ID
> > > > >
> > > > > Caution: EXT Email
> > > > >
> > > > > On Fri, Nov 13, 2020 at 07:04:06PM +0800, Alice Guo wrote:
> > > > > > Add DT Binding doc for the Unique ID of i.MX 8M series.
> > > > > >
> > > > > > Signed-off-by: Alice Guo <alice.guo@nxp.com>
> > > > > > ---
> > > > > >  .../devicetree/bindings/arm/fsl.yaml          | 25
> > > > > +++++++++++++++++++
> > > > > >  1 file changed, 25 insertions(+)
> > > > > >
> > > > > > diff --git a/Documentation/devicetree/bindings/arm/fsl.yaml
> > > > > > b/Documentation/devicetree/bindings/arm/fsl.yaml
> > > > > > index e4db0f9ed664..f4faebbb57da 100644
> > > > > > --- a/Documentation/devicetree/bindings/arm/fsl.yaml
> > > > > > +++ b/Documentation/devicetree/bindings/arm/fsl.yaml
> > > > > > @@ -901,6 +901,31 @@ properties:
> > > > > >                - fsl,s32v234-evb           # S32V234-EVB2
> > > Customer
> > > > > Evaluation Board
> > > > > >            - const: fsl,s32v234
> > > > > >
> > > > > > +  soc:
> > > > > > +    type: object
> > > > > > +    properties:
> > > > > > +      compatible:
> > > > > > +        oneOf:
> > > > > > +          - description: i.MX8M SoCs
> > > > > > +            items:
> > > > > > +              - enum:
> > > > > > +                  - fsl,imx8mm-soc
> > > > > > +                  - fsl,imx8mn-soc
> > > > > > +                  - fsl,imx8mp-soc
> > > > > > +                  - fsl,imx8mq-soc
> > > > > > +              - const: simple-bus
> > > > > > +
> > > > > > +          - description: Other SoCs
> > > > > > +            items:
> > > > > > +              - const: simple-bus
> > > > > > +
> > > > > > +      nvmem-cells:
> > > > > > +        maxItems: 1
> > > > > > +        description: Phandle to the SOC Unique ID provided by
> > > > > > + a nvmem node
> > > > > > +
> > > > > > +      nvmem-cells-names:
> > > > > > +        const: soc_unique_id
> > > > > > +
> > > > > >  additionalProperties: true
> > > > >
> > > > > The "soc" node should be required for these compatibles.
> > > > > Otherwise you will have to stay with this
> > > > > backwards-compatible-DTB-device-initcall-glue for many years...
> > > > > I think you
> > > can achieve it with allOf.
> > > > >
> > > > [Alice Guo]Hi,
> > > > I find that my description for compatible is ambiguous. There are
> > > > two kinds of
> > > compatible of the "soc" node:
> > > > 1. For dtsi files used for SoCs other than imx8m series SoCs and
> > > > old version dtsi files used for imx8m series SoCs, compatible of
> > > > the "soc" node is
> > > "simple-bus".
> > > > 2. For new version dtsi files used for imx8m series SoCs,
> > > > compatible of the
> > > "soc" node is {"fsl,imx8mX-soc","simple-bus"}.
> > > >
> > > > "nvmem-cell" is an optional property.
> > > >
> > > > I do not understand what you mean. You mean that limit the
> > > > compatible of
> > > "soc" node must include " fsl,imx8mX-soc" in new version dts files.
> > > Is my understanding correct?
> > >
> > > All new DTS files should have soc node with "fsl,imx8mX-soc" and
> > > this should be required by dtschema. The nvmem-cells and related
> > > properties do not look like optional. From the hardware perspective
> > > - they are always present. From the driver point of view: they are required
> and driver will fail to work.
> >
> > [Alice Guo]
> > +  soc:
> > +    type: object
> > +    properties:
> > +      compatible:
> > +        oneOf:
> > +          - description: new version DTS for i.MX8M SoCs
> > +            items:
> > +              - enum:
> > +                  - fsl,imx8mm-soc
> > +                  - fsl,imx8mn-soc
> > +                  - fsl,imx8mp-soc
> > +                  - fsl,imx8mq-soc
> > +              - const: simple-bus
> > +
> > +          - description: other SoCs and old version DTS for i.MX8M SoCs
> > +            items:
> > +              - const: simple-bus
> > +
> > +      nvmem-cells:
> > +        maxItems: 1
> > +        description: Phandle to the SOC Unique ID provided by a nvmem
> > + node
> > +
> > +      nvmem-cells-names:
> > +        const: soc_unique_id
> > +
> > +    allOf:
> > +      - if:
> > +          properties:
> > +            compatible:
> > +              contains:
> > +                enum:
> > +                  - fsl,imx8mm-soc
> > +                  - fsl,imx8mn-soc
> > +                  - fsl,imx8mp-soc
> > +                  - fsl,imx8mq-soc
> > +                const: simple-bus
> > +
> > +        then:
> > +          required:
> > +            - nvmem-cells
> > +            - nvmem-cells-names
> >
> > The above is my modification. Is that ok?
> 
> Does not look like solving anything.

If restrict that the newly added DTS file must have "fsl,imx8mX-soc" attributes, it cannot pass make dtbs_check because
there are other DTS files which have soc node but are not used for i.mx8m family SoCs.

Best regards,
Alice Guo

> Best regards,
> Krzysztof