On Sun, Feb 13, 2022 at 07:58:28PM +0000, Cristian Marussi wrote:
> SCMI protocols in the platform can optionally signal to the OSPM agent
> the expected execution latency for a specific resource/operation pair.
>
> Introduce an SCMI system wide optional property to describe a global time
> threshold which can be configured on a per-platform base to determine the
> opportunity, or not, for an SCMI command advertised to have a higher
> latency than the threshold, to be considered for atomic operations:
> high-latency SCMI synchronous commands should be preferably issued in the
> usual non-atomic mode.
>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
> ---
> v3 --> v4
> - renamed property to atomic-threshold-us
> v1 --> v2
> - rephrased the property description
> ---
> .../devicetree/bindings/firmware/arm,scmi.yaml | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> index eae15df36eef..3ffa669b91af 100644
> --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> @@ -81,6 +81,15 @@ properties:
> '#size-cells':
> const: 0
>
> + atomic-threshold-us:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + An optional time value, expressed in microseconds, representing, on this
> + platform, the threshold above which any SCMI command, advertised to have
> + an higher-than-threshold execution latency, should not be considered for
> + atomic mode of operation, even if requested.
> + If left unconfigured defaults to zero.
This can be expressed as 'default: 0'.
> +
> arm,smc-id:
> $ref: /schemas/types.yaml#/definitions/uint32
> description:
> @@ -264,6 +273,8 @@ examples:
> #address-cells = <1>;
> #size-cells = <0>;
>
> + atomic_threshold = <10000>;
> +
> scmi_devpd: protocol@11 {
> reg = <0x11>;
> #power-domain-cells = <1>;
> --
> 2.17.1
>
>
