Re: [PATCH v3 01/14] dt-bindings: display: renesas,cmm: Add R-Car CMM documentation

[Jacopo Mondi]

Hi Laurent, Geert,


On Thu, Sep 05, 2019 at 03:20:59PM +0300, Laurent Pinchart wrote:
> Hi Geert,
>
> On Thu, Sep 05, 2019 at 02:05:34PM +0200, Geert Uytterhoeven wrote:
> > On Thu, Sep 5, 2019 at 1:50 PM Laurent Pinchart wrote:
> > > On Fri, Aug 30, 2019 at 08:01:09PM +0200, Jacopo Mondi wrote:
> > > > On Mon, Aug 26, 2019 at 01:15:50PM +0300, Laurent Pinchart wrote:
> > > > > How about converting this binding to yaml alreay ? It should be fairly
> > > > > simple.
> > > >
> > > > I'm trying to, and I'm having my portion of fun time at it.
> > > >
> > > > The definition of the schema itself seems good, but I wonder, is this
> > > > the first renesas schema we have? Because it seems to me the schema
> > > > validator is having an hard time to digest the examplea 'clocks' and
> > > > 'power-domains' properties, which have 1 phandle and 2 specifiers and 1
> > > > phandle and 1 specifier respectively for Rensas SoCs.
> > > >
> > > > In other words, if in the example I have:
> > > >
> > > >  examples:
> > > >    - |
> > > >      cmm0: cmm@fea40000 {
> > > >           compatible = "renesas,r8a7796-cmm";
> > > >           reg = <0 0xfea40000 0 0x1000>;
> > > >           clocks = <&cpg 711>              <---- 1 phandle + 1 specifier
> > > >           resets = <&cpg 711>;
> > > >           power-domains = <&sysc>;         <---- 1 phandle
> > > >      };
> > > >
> > > > The schema validation is good.
> > > >
> > > > While if I use an actual example
> > > >    - |
> > > >      cmm0: cmm@fea40000 {
> > > >           compatible = "renesas,r8a7796-cmm";
> > > >           reg = <0 0xfea40000 0 0x1000>;
> > > >           clocks = <&cpg CPG_MOD 711>         <---- 1 phandle + 2 specifier
> > > >           resets = <&cpg 711>;
> > > >           power-domains = <&sysc R8A7796_PD_ALWAYS_ON>; <---- 1 phandle
> > > >      };                                                       + 1 specfier
> > > >
> > > > The schema validation fails...
> > > > Error: Documentation/devicetree/bindings/display/renesas,cmm.example.dts:20.29-30 syntax error
> > > > FATAL ERROR: Unable to parse input tree
> > > >
> > > > Are clocks properties with > 2 entries and power-domains properties with
> > > > > 1 entries supported?
> > > >
> > > > Because from what I read here:
> > > > https://github.com/robherring/yaml-bindings/blob/master/schemas/clock/clock.yaml
> > > > "The length of a clock specifier is defined by the value of a #clock-cells
> > > > property in the clock provider node."
> > > >
> > > > And that's expected, but is the examples actually validated against the
> > > > clock provider pointed by the phandle? Because in that case, if we had a
> > > > yaml schema for the cpg-mssr provider, it would indeed specify clock-cells=2.
> > > >
> > > > Do we need a schema for cpg-mssr first, or am I doing something else
> > > > wrong?
> > >
> > > I think you just need to #include the headers that define CPG_MOD and
> > > R8A7796_PD_ALWAYS_ON.
> >
> > If that helps, you might want to replace the symbols in the examples by their
> > actual values (1 resp. 32).
> >
> > And perhaps keep the symbols as comments?
> >
> >         clocks = <&cpg 1 /* CPG_MOD */ 711>;
> >         power-domains = <&sysc 32 /* R8A7796_PD_ALWAYS_ON */>;
>
> I think adding the required #include at the beginning of the example is
> a better solution.

I didn't realize that, but it actually makes sense, as the example is
extracted and actually compiled from the yaml schema.. brilliant!

With a simple:

--- a/Documentation/devicetree/bindings/display/renesas,cmm.yaml
+++ b/Documentation/devicetree/bindings/display/renesas,cmm.yaml
@@ -51,6 +51,9 @@ additionalProperties: false

 examples:
   - |
+    #include <dt-bindings/clock/r8a7796-cpg-mssr.h>
+    #include <dt-bindings/power/r8a7796-sysc.h>

The example now compiles.

Thanks, I will submit the bindings in yaml format in next iteration.

>
> --
> Regards,
>
> Laurent Pinchart

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