[PATCH v2 5/9] dt-bindings: firmware: arm,scmi: Add atomic_threshold optional property

Cristian Marussi
2022-02-01T17:16:32Z

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@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
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..646bdf2873b5 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:
+ $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.
+
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