[PATCH v4 1/2] dt-bindings: firmware: arm,scmi: Document arm,no-completion-irq property

[Cristian Marussi]

On Sat, Jan 17, 2026 at 02:02:28AM +0100, Marek Vasut wrote:
> Document new property arm,no-completion-irq . This optional property
> is intended for hardware that does not generate completion interrupts
> and can be used to unconditionally enable forced polling mode of
> operation.
> 
> With this property set, such implementations which do not generate
> interrupts can be interacted with, until they are fixed to generate
> interrupts properly.
> 
> Note that, because the original base protocol exchange also requires
> some sort of completion mechanism, it is not possible to query SCMI
> itself for this property and it must be described in DT. While this
> does look a bit like policy, the SCMI provider is part of the
> hardware, hence DT.
> 
> Reviewed-by: Rob Herring (Arm) <robh at kernel.org>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> ---
> Cc: Conor Dooley <conor+dt at kernel.org>
> Cc: Cristian Marussi <cristian.marussi at arm.com>
> Cc: Florian Fainelli <florian.fainelli at broadcom.com>
> Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
> Cc: Rob Herring <robh at kernel.org>
> Cc: Sudeep Holla <sudeep.holla at arm.com>
> Cc: arm-scmi at vger.kernel.org
> Cc: devicetree at vger.kernel.org
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-renesas-soc at vger.kernel.org
> ---
> V2: s at mean@&t and limit poll transport to mailbox/shmem only
> V3: - Reformat the commit message, expand property description to
>       explicitly spell out this is hardware description.
>     - Rename property from arm,poll-transport to arm,no-completion-irq
> V4: - Update first paragraph of commit message and property description
>     - Add RB from Rob
> ---
>  .../devicetree/bindings/firmware/arm,scmi.yaml         | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> index be817fd9cc34b..d06cca9273c48 100644
> --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> @@ -146,6 +146,13 @@ properties:
>        this platform. If set, the value should be non-zero.
>      minimum: 1
>  
> +  arm,no-completion-irq:
> +    type: boolean
> +    description:

Shouldn't these two points have to be swapped as per Sudeep and Rob
suggestions ?

    description:
	....
    type: boolean

> +      This optional property is intended for hardware that does not generate
> +      completion interrupts and can be used to unconditionally enable forced
> +      polling mode of operation.
> +
>    arm,smc-id:
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:
> @@ -379,6 +386,9 @@ then:
>      - shmem
>  
>  else:
> +  properties:
> +    arm,no-completion-irq: false
> +
>    if:
>      properties:

With the above corrected, LGTM.

Reviewed-by: Cristian Marussi <cristian.marussi at arm.com>

Thanks,
Cristian