Re: [PATCH 3/8] dt-bindings: serial: fsl-linflexuart: Add compatible for S32G2

[Radu Nicolae Pirea (NXP OSS)]

On Thu, 2021-08-12 at 18:27 +0200, Andreas Färber wrote:
> On 05.08.21 08:54, Chester Lin wrote:
> > Add a compatible string for the uart binding of NXP S32G2
> > platforms. Here
> > we use "s32v234-linflexuart" as fallback since the current
> > linflexuart
> > driver still works on S32G2.
> > 
> > Signed-off-by: Chester Lin <clin@xxxxxxxx>
> > ---
> >  .../bindings/serial/fsl,s32-linflexuart.yaml  | 26
> > ++++++++++++++++---
> >  1 file changed, 22 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-
> > linflexuart.yaml
> > b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > index acfe34706ccb..e731f3f6cea4 100644
> > --- a/Documentation/devicetree/bindings/serial/fsl,s32-
> > linflexuart.yaml
> > +++ b/Documentation/devicetree/bindings/serial/fsl,s32-
> > linflexuart.yaml
> > @@ -21,10 +21,20 @@ allOf:
> >  
> >  properties:
> >    compatible:
> > -    description: The LINFlexD controller on S32V234 SoC, which can
> > be
> > -      configured in UART mode.
> > -    items:
> > -      - const: fsl,s32v234-linflexuart
> > +    minItems: 1
> > +    maxItems: 2
> 
> Are these necessary for oneOf?
> 
> > +    oneOf:
> > +      - description: The LINFlexD controller on S32G2 SoC, which
> > can be
> > +          configured in UART mode.
> > +        items:
> > +          - enum:
> > +              - fsl,s32g2-linflexuart
> > +          - const: fsl,s32v234-linflexuart
> 
> This reads inconsistent to me: Either this oneOf is for S32G2 only,
> then
> please turn the enum into a const. Or change the description to "on
> SoCs
> compatible with S32V234" if we expect the enum list to grow.
> 
> I believe the idea here was to avoid unnecessary driver compatible
> and
> earlycon compatible additions, while preparing for eventual quirks
> specific to S32G2.
> 
> @NXP: Should this be s32g2- like above or s32g274a- specifically? Do
> you
> agree this is a useful thing to prepare here, as opposed to using
> only
> s32v234- in the s32g2* DT?

s32g2- is fine, but the vendor should be nxp, not fsl.
nxp,s32g2-linflexuart

> 
> I assume the ordering is done alphabetically as S32G < S32V;
> alternatively we might order S32V234 first and then the compatible
> ones.
> 
> > +
> > +      - description: The LINFlexD controller on S32V234 SoC, which
> > can be
> > +          configured in UART mode.
> > +        items:
> > +          - const: fsl,s32v234-linflexuart
> 
> To minimize this S32G2 patch, would it be valid to do oneOf for the
> single S32V in the preceding patch already? Then we would avoid the
> text
> movement and re-indentation above and more easily see the lines newly
> getting added for S32G2.
> 
> >  
> >    reg:
> >      maxItems: 1
> > @@ -41,8 +51,16 @@ unevaluatedProperties: false
> >  
> >  examples:
> >    - |
> > +    /* S32V234 */
> 
> Could this be:
>   - description: S32V234
>     |
> ?
> 
> >      serial@40053000 {
> >          compatible = "fsl,s32v234-linflexuart";
> >          reg = <0x40053000 0x1000>;
> >          interrupts = <0 59 4>;
> >      };
> > +
> > +    /* S32G2 */
> 
> This should not be part of the S32V example, but a new one:
> 
>   - |
> 
> (or with description, as discussed above)
> 
> > +    serial@401c8000 {
> > +        compatible = "fsl,s32g2-linflexuart", "fsl,s32v234-
> > linflexuart";
> 
> Potentially affected by naming discussions above.
> 
> > +        reg = <0x401c8000 0x3000>;
> > +        interrupts = <0 82 1>;
> > +    };
> 
> Regards,
> Andreas
>