106 lines
4.5 KiB
Plaintext
106 lines
4.5 KiB
Plaintext
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MSM thermal driver (MSM_THERMAL)
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MSM_THERMAL is a kernel platform driver which regulates thermal conditions
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on the device during kernel boot. The goal of MSM_THERMAL is to prevent the
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temperature of the system from exceeding a thermal limit at which it cannot
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operate. Examples are CPU junction thermal limit, or POP memory thermal limit.
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The MSM_THERMAL driver polls the TSENS sensor hardware during boot, and
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reduces the maximum CPU frequency allowed in steps, to limit power/thermal
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output when a threshold temperature is crossed. It restores the maximum CPU
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frequency allowed in the same stepwise fashion when the threshold temperature
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(with hysteresis gap) is cleared.
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The devicetree representation of the MSM_THERMAL block should be:
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Required properties
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- compatible: "qcom,msm-thermal"
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- qcom,sensor-id: The id of the TSENS sensor polled for temperature.
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Typically the sensor closest to CPU0.
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- qcom,poll-ms: Sampling interval to read sensor, in ms.
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- qcom,limit-temp: Threshold temperature to start stepping CPU down, in degC.
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- qcom,temp-hysteresis: Degrees C below threshold temperature to step CPU up.
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- qcom,freq-step: Number of frequency steps to take on each CPU mitigation.
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Optional properties
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- qcom,freq-control-mask: The cpu mask that will be used to determine if a
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core can be used for freq control.
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- qcom,core-limit-temp: Threshold temperature to start shutting down cores
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in degC
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- qcom,core-temp-hysterisis: Degrees C below which the cores will be brought
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online in sequence.
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- qcom,core-control-mask: The cpu mask that will be used to determine if a
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core can be controlled or not. A mask of 0 indicates
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the feature is disabled.
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- qcom,vdd-restriction-temp: When temperature is below this threshold, will
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enable vdd restriction which will set higher voltage on
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key voltage rails, in degC.
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- qcom,vdd-restriction-temp-hysteresis: When temperature is above this threshold
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will disable vdd restriction on key rails, in degC.
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- qcom,pmic-sw-mode-temp: Threshold temperature to disable auto mode on the
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rail, in degC. If this property exists,
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qcom,pmic-sw-mode-temp-hysteresis and
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qcom,pmic-sw-mode-regs need to exist, otherwise return error.
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- qcom,pmic-sw-mode-temp-hysteresis: Degree below threshold temperature to
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enable auto mode on the rail, in degC. If this property exists,
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qcom,pmic-sw-mode-temp and qcom,pmic-sw-mode-regs need to
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exist, otherwise return error.
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- qcom,pmic-sw-mode-regs: Array of the regulator names that will want to
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disable/enable automode based on the threshold. If this
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property exists, qcom,pmic-sw-mode-temp and
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qcom,pmic-sw-mode-temp-hysteresis need to exist, otherwise
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return error. Also, if this property is defined, will have to
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define <consumer_supply_name>-supply = <&phandle_of_regulator>
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- <consumer_supply_name>-supply = <&phandle_of_regulator>: consumer_supply_name
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is the name that's defined in thermal driver.
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phandle_of_regulator is defined by reuglator device tree.
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Optional child nodes
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- qcom,<vdd restriction child node name>: Define the name of the child node.
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If this property exisits, qcom,vdd-rstr-reg, qcom,levels
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need to exist. qcom,min-level is optional if qcom,freq-req
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exists, otherwise it's required.
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- qcom,vdd-rstr-reg: Name of the rail
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- qcom,levels: Array of the level values. Unit is corner voltage for voltage request
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or kHz for frequency request.
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- qcom,min-level: Request this level as minimum level when disabling voltage
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restriction. Unit is corner voltage for voltage request.
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This will not be required if qcom,freq-req exists.
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- qcom,freq-req: Flag to determine if we should restrict frequency on this rail
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instead of voltage.
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Example:
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qcom,msm-thermal {
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compatible = "qcom,msm-thermal";
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qcom,sensor-id = <0>;
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qcom,poll-ms = <250>;
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qcom,limit-temp = <60>;
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qcom,temp-hysteresis = <10>;
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qcom,freq-step = <2>;
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qcom,freq-control-mask = <0xf>
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qcom,core-limit-temp = <90>;
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qcom,core-temp-hysterisis = <10>;
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qcom,core-control-mask = <7>;
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qcom,pmic-sw-mode-temp = <90>;
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qcom,pmic-sw-mode-temp-hysteresis = <80>;
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qcom,pmic-sw-mode-regs = "vdd_dig";
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qcom,vdd-restriction-temp = <5>;
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qcom,vdd-restriction-temp-hysteresis = <10>;
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vdd_dig-supply=<&pm8841_s2_floor_corner>
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qcom,vdd-dig-rstr{
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qcom,vdd-rstr-reg = "vdd_dig";
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qcom,levels = <5 7 7>; /* Nominal, Super Turbo, Super Turbo */
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qcom,min-level = <1>; /* No Request */
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};
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qcom,vdd-apps-rstr{
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qcom,vdd-rstr-reg = "vdd_apps";
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qcom,levels = <1881600 1958400 2265600>;
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qcom,freq-req;
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};
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};
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