RE: [PATCH v2 1/2] dt-bindings: can: renesas,rcar-canfd: Document renesas,fd-only property

[Biju Das]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Sent: 23 November 2025 13:26
> To: biju.das.au <biju.das.au@xxxxxxxxx>; Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>; Vincent Mailhol
> <mailhol@xxxxxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; Conor
> Dooley <conor+dt@xxxxxxxxxx>; Geert Uytterhoeven <geert+renesas@xxxxxxxxx>; magnus.damm
> <magnus.damm@xxxxxxxxx>
> Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>; Fabrizio Castro <fabrizio.castro.jz@xxxxxxxxxxx>; linux-
> can@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH v2 1/2] dt-bindings: can: renesas,rcar-canfd: Document renesas,fd-only property
> 
> On 23/11/2025 12:23, Biju wrote:
> > From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> > The CANFD on RZ/{G2L,G3E} and R-Car Gen4 support 3 modes FD-Only mode,
> > Classical CAN mode and CAN-FD mode. In FD-Only mode, communication in
> > Classical CAN frame format is disabled. Document renesas,fd-only to
> > handle this mode. As these SoCs support 3 modes, update the
> > description of renesas,no-can-fd property and disallow it for R-Car Gen3.
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > ---
> >  v1->v2:
> >   * Added conditional check to disallow fd-only mode for R-Car Gen3.
> > ---
> >  .../bindings/net/can/renesas,rcar-canfd.yaml  | 24
> > ++++++++++++++++---
> >  1 file changed, 21 insertions(+), 3 deletions(-)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > index f4ac21c68427..a52244f0b5d1 100644
> > ---
> > a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> > +++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yam
> > +++ l
> > @@ -125,9 +125,17 @@ properties:
> >    renesas,no-can-fd:
> >      $ref: /schemas/types.yaml#/definitions/flag
> >      description:
> > -      The controller can operate in either CAN FD only mode (default) or
> > -      Classical CAN only mode.  The mode is global to all channels.
> > -      Specify this property to put the controller in Classical CAN only mode.
> > +      The controller can operate in either CAN-FD mode (default) or FD-Only
> > +      mode (RZ/{G2L,G3E} and R-Car Gen4) or Classical CAN mode. Specify this
> > +      property to put the controller in Classical CAN mode.
> > +
> > +  renesas,fd-only:
> > +    $ref: /schemas/types.yaml#/definitions/flag
> > +    description:
> > +      The CANFD on RZ/{G2L,G3E} and R-Car Gen4 SoCs support 3 modes FD-Only
> > +      mode, Classical CAN mode and CAN-FD mode (default). In FD-Only mode,
> > +      communication in Classical CAN frame format is disabled. Specify this
> > +      property to put the controller in FD-Only mode.
> >
> >    assigned-clocks:
> >      description:
> > @@ -267,6 +275,16 @@ allOf:
> >        patternProperties:
> >          "^channel[6-7]$": false
> >
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - renesas,rcar-gen3-canfd
> > +    then:
> > +      properties:
> > +        renesas,fd-only: false
> > +
> 
> You did not respond to my first paragraph from previous version. As I said, you now need oneOf to
> restrict these, since you are not using simple enum.

This is restricting for R-Car Gen3. DT binding check returns error if 'renesas,fd-only"
is defined for R-Car Gen3.

Am I missing anything here?

Cheers,
Biju