Re: [PATCH v2 1/2] dt-bindings: watchdog: realtek,otto-wdt: Add fallback compatible

[Guenter Roeck]

On Tue, May 12, 2026 at 10:48:53PM +0200, Sander Vanheule wrote:
> As all known hardware instantiations of this watchdog behave the same, a
> fallback compatible can be added.
> 
> To remain compatible with existing single-compatible bindings, the
> current compatibles are duplicated. New compatibles should only be added
> to the list with fallback.
> 
> Signed-off-by: Sander Vanheule <sander@xxxxxxxxxxxxx>
> ---
> Changes since v1:
> - Fix indendations
> - Add deprecated property to old compatible
> - Use two-part compatible in example
> ---
>  .../bindings/watchdog/realtek,otto-wdt.yaml   | 22 ++++++++++++++-----
>  1 file changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> index 1f5390a67cdb..e470e0fcbb2a 100644
> --- a/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml
> @@ -25,11 +25,21 @@ allOf:
>  
>  properties:
>    compatible:
> -    enum:
> -      - realtek,rtl8380-wdt
> -      - realtek,rtl8390-wdt
> -      - realtek,rtl9300-wdt
> -      - realtek,rtl9310-wdt
> +    oneOf:
> +      - items:
> +          - enum:
> +              - realtek,rtl8380-wdt
> +              - realtek,rtl8390-wdt
> +              - realtek,rtl9300-wdt
> +              - realtek,rtl9310-wdt
> +          - const: realtek,otto-wdt

For the Apple watchdog driver, the generic property "apple,wdt" is
considered to be bad and is not supposed to be used for newer chips.
For this watchdog driver, a generic property is introduced.

What is the overall logic ? Is there some rule when a generic property
such as "realtek,otto-wdt" is appropriate and preferred, and when it isn't
(as in "apple,wdt") ?

Thanks,
Guenter