The RPM MSG RAM contains per-RPM-master (e.g. APPS, ADSP etc.) sleep statistics. They let one assess which core is actively preventing the system from entering a true low-power mode. Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> --- .../bindings/soc/qcom/qcom,rpm-master-stats.yaml | 69 ++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml new file mode 100644 index 000000000000..8a654979ce92 --- /dev/null +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,rpm-master-stats.yaml @@ -0,0 +1,69 @@ +# 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@xxxxxxxxxx> + +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 decisons + (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"; + }; +... -- 2.40.0
