温控驱动（五）dts参数解析、节点作用

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温控驱动（五）dts参数解析、节点作用

我们先看下dts中，各个参数的分析如下：

poll-ms代表KTM检测温度的间隔

limit-temp KTM调频的温度

temp-hysteresis 当温度降到limit-temp - temp-hysteresis 频率升到前面档位

freq-step 每次调频的步长（就是cpu频率的档位）

core-limit-temp代表KTM拔核（除cpu0）的温度

core-temp-hysteresis当温度降到core-limit-temp - core-temp-hysteresis，各个cpu online

hotplug-temp 代表KTM拔核的温度

holhotplutplug-temp-hysteresis 当温度降到hotplug-temp - holtplug-temp-hysteresis各个恢复cpu online

这里3个的温度值除了hotplug其他的都在thermal-engine起来后失效了，hotplug是在thermal-engine起来后起作用。

 561         qcom,msm-thermal {562                 compatible = "qcom,msm-thermal";563                 qcom,sensor-id = <3>;564                 qcom,poll-ms = <250>;565                 qcom,limit-temp = <60>;566                 qcom,temp-hysteresis = <10>;567                 qcom,freq-step = <2>;568                 qcom,core-limit-temp = <80>;569                 qcom,core-temp-hysteresis = <10>;570                 qcom,hotplug-temp = <97>;571                 qcom,hotplug-temp-hysteresis = <12>;572                 qcom,freq-mitigation-temp = <97>;573                 qcom,freq-mitigation-temp-hysteresis = <12>;574                 qcom,freq-mitigation-value = <400000>;575                 qcom,online-hotplug-core;576                 qcom,therm-reset-temp = <115>;577                 qcom,disable-cx-phase-ctrl;578                 qcom,disable-gfx-phase-ctrl;579                 qcom,disable-vdd-mx;580                 qcom,disable-psm;581                 qcom,disable-ocr;582                 qcom,vdd-restriction-temp = <5>;583                 qcom,vdd-restriction-temp-hysteresis = <10>;584                 vdd-dig-supply = <&pm8909_s1_floor_corner>;585 586                 qcom,vdd-dig-rstr{587                         qcom,vdd-rstr-reg = "vdd-dig";588                         qcom,levels = <5 7 7>; /* Nominal, Super Turbo, Super Turbo */589                         qcom,min-level = <1>; /* No Request */590                 };591         };

节点：

sys/module/msm_thermal/cat sensor_info 读取各个sensor的信息，其实就是dts中如下内容：

 qcom,sensor-information {489                 compatible = "qcom,sensor-information";490                 sensor_information0: qcom,sensor-information-0 {491                         qcom,sensor-type = "tsens";492                         qcom,sensor-name = "tsens_tz_sensor0";493                         qcom,alias-name = "pop_mem";494                 };495 496                 sensor_information1: qcom,sensor-information-1 {497                         qcom,sensor-type =  "tsens";498                         qcom,sensor-name = "tsens_tz_sensor1";499                 };500 501                 sensor_information2: qcom,sensor-information-2 {502                         qcom,sensor-type =  "tsens";503                         qcom,sensor-name = "tsens_tz_sensor2";504                 };505 506                 sensor_information3: qcom,sensor-information-3 {507                         qcom,sensor-type =  "tsens";508                         qcom,sensor-name = "tsens_tz_sensor3";509                 };510 511                 sensor_information4: qcom,sensor-information-4 {512                         qcom,sensor-type = "tsens";513                         qcom,sensor-name = "tsens_tz_sensor4";514                 };515 516                 sensor_information5: qcom,sensor-information-5 {517                         qcom,sensor-type = "adc";518                         qcom,sensor-name = "pa_therm0";519                 };520 521                 sensor_information6: qcom,sensor-information-6 {522                         qcom,sensor-type = "adc";523                         qcom,sensor-name = "case_therm";524                 };525 526                 sensor_information7: qcom,sensor-information-7 {527                         qcom,sensor-type = "alarm";528                         qcom,sensor-name = "pm8909_tz";529                         qcom,scaling-factor = <1000>;530                 };531 532                 sensor_information8: qcom,sensor-information-8 {

字符设备dev/msm_thermal_query，让daemon可以通过ioctl的方式来限制cpu频率

/sys/module/msm_thermal/parameters/enabled节点控制KTM关闭、KTM关闭后不可恢复

/sys/module/msm_thermal/core_control/cpus_offlined  daemon发起cpu的offline

/sys/module/msm_thermal/core_control/enabled  关闭后KTM不能拔核  daemon启动后KTM也不会自动hotplug