xref: /linux/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml (revision e7d759f31ca295d589f7420719c311870bb3166f) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/soc/qcom/qcom,rpm-master-stats.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Qualcomm Technologies, Inc. (QTI) RPM Master Stats
8
9maintainers:
10  - Konrad Dybcio <konrad.dybcio@linaro.org>
11
12description: |
13  The Qualcomm RPM (Resource Power Manager) architecture includes a concept
14  of "RPM Masters". They can be thought of as "the local gang leaders", usually
15  spanning a single subsystem (e.g. APSS, ADSP, CDSP). All of the RPM decisions
16  (particularly around entering hardware-driven low power modes: XO shutdown
17  and total system-wide power collapse) are first made at Master-level, and
18  only then aggregated for the entire system.
19
20  The Master Stats provide a few useful bits that can be used to assess whether
21  our device has entered the desired low-power mode, how long it took to do so,
22  the duration of that residence, how long it took to come back online,
23  how many times a given sleep state was entered and which cores are actively
24  voting for staying awake.
25
26  This scheme has been used on various SoCs in the 2013-2023 era, with some
27  newer or higher-end designs providing this information through an SMEM query.
28
29properties:
30  compatible:
31    const: qcom,rpm-master-stats
32
33  qcom,rpm-msg-ram:
34    $ref: /schemas/types.yaml#/definitions/phandle-array
35    description: Phandle to an RPM MSG RAM slice containing the master stats
36    minItems: 1
37    maxItems: 5
38
39  qcom,master-names:
40    $ref: /schemas/types.yaml#/definitions/string-array
41    description:
42      The name of the RPM Master which owns the MSG RAM slice where this
43      instance of Master Stats resides
44    minItems: 1
45    maxItems: 5
46
47required:
48  - compatible
49  - qcom,rpm-msg-ram
50  - qcom,master-names
51
52additionalProperties: false
53
54examples:
55  - |
56    stats {
57      compatible = "qcom,rpm-master-stats";
58      qcom,rpm-msg-ram = <&apss_master_stats>,
59                         <&mpss_master_stats>,
60                         <&adsp_master_stats>,
61                         <&cdsp_master_stats>,
62                         <&tz_master_stats>;
63      qcom,master-names = "APSS",
64                          "MPSS",
65                          "ADSP",
66                          "CDSP",
67                          "TZ";
68    };
69...
70