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

From: Krzysztof Kozlowski

Date: Sun Nov 23 2025 - 09:21:43 EST


On 23/11/2025 15:17, Biju Das wrote:
> Hi Krzysztof Kozlowski,
>
>> -----Original Message-----
>> From: Biju Das
>> Sent: 23 November 2025 14:06
>> Subject: RE: [PATCH v2 1/2] dt-bindings: can: renesas,rcar-canfd: Document renesas,fd-only property
>>
>>
>>
>>> -----Original Message-----
>>> From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
>>> Sent: 23 November 2025 13:26
>>> 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.y
>>>> +++ am
>>>> +++ 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?

Add on G2L no-can-fd and fd-only. What do you see? What is expected?

Best regards,
Krzysztof