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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/soc/qcom/qcom,rpm-master-stats.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Qualcomm Technologies, Inc. (QTI) RPM Master Stats
maintainers:
- Konrad Dybcio <konrad.dybcio@linaro.org>
description: |
The Qualcomm RPM (Resource Power Manager) architecture includes a concept
of "RPM Masters". They can be thought of as "the local gang leaders", usually
spanning a single subsystem (e.g. APSS, ADSP, CDSP). All of the RPM decisions
(particularly around entering hardware-driven low power modes: XO shutdown
and total system-wide power collapse) are first made at Master-level, and
only then aggregated for the entire system.
The Master Stats provide a few useful bits that can be used to assess whether
our device has entered the desired low-power mode, how long it took to do so,
the duration of that residence, how long it took to come back online,
how many times a given sleep state was entered and which cores are actively
voting for staying awake.
This scheme has been used on various SoCs in the 2013-2023 era, with some
newer or higher-end designs providing this information through an SMEM query.
properties:
compatible:
const: qcom,rpm-master-stats
qcom,rpm-msg-ram:
$ref: /schemas/types.yaml#/definitions/phandle-array
description: Phandle to an RPM MSG RAM slice containing the master stats
minItems: 1
maxItems: 5
qcom,master-names:
$ref: /schemas/types.yaml#/definitions/string-array
description:
The name of the RPM Master which owns the MSG RAM slice where this
instance of Master Stats resides
minItems: 1
maxItems: 5
required:
- compatible
- qcom,rpm-msg-ram
- qcom,master-names
additionalProperties: false
examples:
- |
stats {
compatible = "qcom,rpm-master-stats";
qcom,rpm-msg-ram = <&apss_master_stats>,
<&mpss_master_stats>,
<&adsp_master_stats>,
<&cdsp_master_stats>,
<&tz_master_stats>;
qcom,master-names = "APSS",
"MPSS",
"ADSP",
"CDSP",
"TZ";
};
...
|
