Re: [PATCH 2/5] dt-bindings: watchdog: gpio: Describe minimum heartbeat intervals

[Guenter Roeck]

On 10/16/26 15:16, Florian Fainelli wrote:
> Some GPIO-controlled watchdogs require a minimum interval between input
> transitions. Add an optional hw-min-interval-ms property to describe this
> constraint, allowing the watchdog core to defer early keepalives.
>
> Also remove the 16-bit limit on hw_margin_ms. The generic GPIO driver has
> no hardware register imposing this limit, and its heartbeat interval is
> stored in an unsigned int. The MTX-1 watchdog has a nominal 100-second
> hardware timeout and requires at least 1.6 seconds between transitions.
>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>

For my reference:

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>   .../devicetree/bindings/watchdog/linux,wdt-gpio.yaml  | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/watchdog/linux,wdt-gpio.yaml b/Documentation/devicetree/bindings/watchdog/linux,wdt-gpio.yaml
> index 499f1b7e03f9..1adbfe5e5461 100644
> --- a/Documentation/devicetree/bindings/watchdog/linux,wdt-gpio.yaml
> +++ b/Documentation/devicetree/bindings/watchdog/linux,wdt-gpio.yaml
> @@ -36,7 +36,12 @@ properties:
>       description: Maximum time to reset watchdog circuit (milliseconds).
>       $ref: /schemas/types.yaml#/definitions/uint32
>       minimum: 2
> -    maximum: 65535
> +
> +  hw-min-interval-ms:
> +    description:
> +      Minimum time between watchdog resets in milliseconds. If omitted, the
> +      watchdog can be reset at any time. Must be less than hw_margin_ms.
> +    minimum: 1
>   
>     always-running:
>       type: boolean
> @@ -64,5 +69,7 @@ examples:
>           compatible = "linux,wdt-gpio";
>           gpios = <&gpio3 9 GPIO_ACTIVE_LOW>;
>           hw_algo = "toggle";
> -        hw_margin_ms = <1600>;
> +        hw_margin_ms = <100000>;
> +        hw-min-interval-ms = <1600>;
> +        always-running;
>       };