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
7 title: Qualcomm Technologies, Inc. (QTI) RPM Master Stats
8
9 maintainers:
10 - Konrad Dybcio <konradybcio@kernel.org>
11
12 description: |
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
29 properties:
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 items:
39 maxItems: 1
40
41 qcom,master-names:
42 $ref: /schemas/types.yaml#/definitions/string-array
43 description:
44 The name of the RPM Master which owns the MSG RAM slice where this
45 instance of Master Stats resides
46 minItems: 1
47 maxItems: 5
48
49 required:
50 - compatible
51 - qcom,rpm-msg-ram
52 - qcom,master-names
53
54 additionalProperties: false
55
56 examples:
57 - |
58 stats {
59 compatible = "qcom,rpm-master-stats";
60 qcom,rpm-msg-ram = <&apss_master_stats>,
61 <&mpss_master_stats>,
62 <&adsp_master_stats>,
63 <&cdsp_master_stats>,
64 <&tz_master_stats>;
65 qcom,master-names = "APSS",
66 "MPSS",
67 "ADSP",
68 "CDSP",
69 "TZ";
70 };
71 ...
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