网站建设合作协议书,公司企业墙设计,免费发群二维码的网站,专业企业网站设计网络公司Android Framework系列—CarPower电源管理
智能座舱通常包括中控系统、仪表系统、IVI系统 、后排娱乐、HUD、车联网等。这些系统需要由汽车电源进行供电。由于汽车自身的特殊供电环境#xff08;相比手机方便的充电环境#xff0c;汽车的蓄电池如果没有电是需要专业人士操作…Android Framework系列—CarPower电源管理
智能座舱通常包括中控系统、仪表系统、IVI系统 、后排娱乐、HUD、车联网等。这些系统需要由汽车电源进行供电。由于汽车自身的特殊供电环境相比手机方便的充电环境汽车的蓄电池如果没有电是需要专业人士操作的其电源状态会比较复杂既要满足车内的座舱系统启动足够快又要保证汽车蓄电池的可考性所以出了开机on、关机off外会多出来一些电源状态Suspend、STR、SLEEP等等
所以一般来说软件系统是需要一个专门的电源管理模块的。
CarPower电源管理
Android Automotive基于Android平台的车载信息娱乐系统提供了CarPower模块用于管理电源状态。CarPower Service属于CarService在SystemSever的startOtherService阶段启动。 CarPower Service根据来自于 Vehicle HALHal层服务的电源状态通知进行相关的逻辑判断后应用电源策略简单理解成告知某些服务Enable 或者Disable、发送状态通知给它自身的监听者、回复ReportVehcileHAL处理结果。 Vehicle HAL的电源状态一般来讲是来自于MCU的can通信 或者以太网通信具体形式由Vehicle HAL和相关供应商决定。电源状态变化时MCU一般会拉低或者拉高某个引脚然后通知事件给VehicleHALVehicleHAL再通过PropertyEvent通知给CarPower Service。Android系统处理完电源状态后有超时要求再由VehiclHAL告知MCU,MCU在对某个引脚进行相关操作。
CarPower电源管理的开机流程
下面以Android车载系统开机为例。说明一下CarPower模块的开机时序。代码基于Android12.
CarPower服务启动Android系统开机上电在systemServer中启动CarService。
// frameworks/base/services/java/com/android/server/SystemServer.java/*** Starts a miscellaneous grab bag of stuff that has yet to be refactored and organized.*/
private void startOtherServices(NonNull TimingsTraceAndSlog t) {if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_AUTOMOTIVE)) {t.traceBegin(StartCarServiceHelperService);final SystemService cshs mSystemServiceManager.startService(CAR_SERVICE_HELPER_SERVICE_CLASS);if (cshs instanceof Dumpable) {mDumper.addDumpable((Dumpable) cshs);}if (cshs instanceof DevicePolicySafetyChecker) {dpms.setDevicePolicySafetyChecker((DevicePolicySafetyChecker) cshs);}t.traceEnd();}}// frameworks/opt/car/services/src/com/android/internal/car/CarServiceHelperService.java
public void onStart() {EventLog.writeEvent(EventLogTags.CAR_HELPER_START, mHalEnabled ? 1 : 0);IntentFilter filter new IntentFilter(Intent.ACTION_REBOOT);filter.addAction(Intent.ACTION_SHUTDOWN);mContext.registerReceiverForAllUsers(mShutdownEventReceiver, filter, null, null);mCarWatchdogDaemonHelper.addOnConnectionChangeListener(mConnectionListener);mCarWatchdogDaemonHelper.connect();// 启动了CarService------------------------------------------Intent intent new Intent();intent.setPackage(com.android.car);intent.setAction(ICarConstants.CAR_SERVICE_INTERFACE);if (!mContext.bindServiceAsUser(intent, mCarServiceConnection, Context.BIND_AUTO_CREATE,UserHandle.SYSTEM)) {Slog.wtf(TAG, cannot start car service);}loadNativeLibrary();
}CarService启动后会创建CarPower实例。
!-- packages/services/Car/service/AndroidManifest.xml --
application android:labelstring/app_titleandroid:directBootAwaretrueandroid:allowBackupfalseandroid:persistenttrueservice android:name.CarServiceandroid:singleUsertrueintent-filteraction android:nameandroid.car.ICar //intent-filter/service
// packages/services/Car/service/src/com/android/car/ICarImpl.java
public class ICarImpl extends ICar.Stub {public ICarImpl(Context serviceContext, IVehicle vehicle, SystemInterface systemInterface,CanBusErrorNotifier errorNotifier, String vehicleInterfaceName) {this(serviceContext, vehicle, systemInterface, errorNotifier, vehicleInterfaceName,/* carUserService */ null, /* carWatchdogService */ null);}VisibleForTestingICarImpl(Context serviceContext, IVehicle vehicle, SystemInterface systemInterface,CanBusErrorNotifier errorNotifier, String vehicleInterfaceName,Nullable CarUserService carUserService,Nullable CarWatchdogService carWatchdogService) {mContext serviceContext;mSystemInterface systemInterface;mHal new VehicleHal(serviceContext, vehicle);// Do this before any other service components to allow feature check. It should work// even without init. For that, vhal get is retried as it can be too early.VehiclePropValue disabledOptionalFeatureValue mHal.getIfAvailableOrFailForEarlyStage(VehicleProperty.DISABLED_OPTIONAL_FEATURES, INITIAL_VHAL_GET_RETRY);String[] disabledFeaturesFromVhal null;if (disabledOptionalFeatureValue ! null) {String disabledFeatures disabledOptionalFeatureValue.value.stringValue;if (disabledFeatures ! null !disabledFeatures.isEmpty()) {disabledFeaturesFromVhal disabledFeatures.split(,);}}if (disabledFeaturesFromVhal null) {disabledFeaturesFromVhal new String[0];}Resources res mContext.getResources();String[] defaultEnabledFeatures res.getStringArray(R.array.config_allowed_optional_car_features);mFeatureController new CarFeatureController(serviceContext, defaultEnabledFeatures,disabledFeaturesFromVhal , mSystemInterface.getSystemCarDir());CarLocalServices.addService(CarFeatureController.class, mFeatureController);mVehicleInterfaceName vehicleInterfaceName;mUserManagerHelper new CarUserManagerHelper(serviceContext);if (carUserService ! null) {mCarUserService carUserService;} else {UserManager userManager (UserManager) serviceContext.getSystemService(Context.USER_SERVICE);int maxRunningUsers res.getInteger(com.android.internal.R.integer.config_multiuserMaxRunningUsers);mCarUserService new CarUserService(serviceContext, mHal.getUserHal(),mUserManagerHelper, userManager, ActivityManager.getService(), maxRunningUsers);}mCarOccupantZoneService new CarOccupantZoneService(serviceContext);mSystemActivityMonitoringService new SystemActivityMonitoringService(serviceContext);// 这里创建了CarPower服务实例-----------------------------------------------------------mCarPowerManagementService new CarPowerManagementService(mContext, mHal.getPowerHal(),systemInterface, mCarUserService);if (mFeatureController.isFeatureEnabled(CarFeatures.FEATURE_CAR_USER_NOTICE_SERVICE)) {mCarUserNoticeService new CarUserNoticeService(serviceContext);} else {mCarUserNoticeService null;}mCarPropertyService new CarPropertyService(serviceContext, mHal.getPropertyHal());mCarDrivingStateService new CarDrivingStateService(serviceContext, mCarPropertyService);mCarUXRestrictionsService new CarUxRestrictionsManagerService(serviceContext,mCarDrivingStateService, mCarPropertyService);if (mFeatureController.isFeatureEnabled(Car.OCCUPANT_AWARENESS_SERVICE)) {mOccupantAwarenessService new OccupantAwarenessService(serviceContext);} else {mOccupantAwarenessService null;}mCarPackageManagerService new CarPackageManagerService(serviceContext,mCarUXRestrictionsService,mSystemActivityMonitoringService,mCarUserService);mPerUserCarServiceHelper new PerUserCarServiceHelper(serviceContext, mCarUserService);mCarBluetoothService new CarBluetoothService(serviceContext, mPerUserCarServiceHelper);mCarInputService new CarInputService(serviceContext, mHal.getInputHal(), mCarUserService);mCarProjectionService new CarProjectionService(serviceContext, null /* handler */, mCarInputService, mCarBluetoothService);mGarageModeService new GarageModeService(mContext);mAppFocusService new AppFocusService(serviceContext, mSystemActivityMonitoringService);mCarAudioService new CarAudioService(serviceContext);mCarNightService new CarNightService(serviceContext, mCarPropertyService);mFixedActivityService new FixedActivityService(serviceContext);mInstrumentClusterService new InstrumentClusterService(serviceContext,mAppFocusService, mCarInputService);mSystemStateControllerService new SystemStateControllerService(serviceContext, mCarAudioService, this);mCarStatsService new CarStatsService(serviceContext);mCarStatsService.init();if (mFeatureController.isFeatureEnabled(Car.VEHICLE_MAP_SERVICE)) {mVmsBrokerService new VmsBrokerService(mContext, mCarStatsService);} else {mVmsBrokerService null;}if (mFeatureController.isFeatureEnabled(Car.DIAGNOSTIC_SERVICE)) {mCarDiagnosticService new CarDiagnosticService(serviceContext,mHal.getDiagnosticHal());} else {mCarDiagnosticService null;}if (mFeatureController.isFeatureEnabled(Car.STORAGE_MONITORING_SERVICE)) {mCarStorageMonitoringService new CarStorageMonitoringService(serviceContext,systemInterface);} else {mCarStorageMonitoringService null;}mCarConfigurationService new CarConfigurationService(serviceContext, new JsonReaderImpl());mCarLocationService new CarLocationService(serviceContext);mCarTrustedDeviceService new CarTrustedDeviceService(serviceContext);mCarMediaService new CarMediaService(serviceContext, mCarUserService);mCarBugreportManagerService new CarBugreportManagerService(serviceContext);if (!Build.IS_USER) {mCarExperimentalFeatureServiceController new CarExperimentalFeatureServiceController(serviceContext);} else {mCarExperimentalFeatureServiceController null;}if (carWatchdogService null) {mCarWatchdogService new CarWatchdogService(serviceContext);} else {mCarWatchdogService carWatchdogService;}// 将电源服务添加到Car本地服务List中-----------------------------CarLocalServices.addService(CarPowerManagementService.class, mCarPowerManagementService);CarLocalServices.addService(CarPropertyService.class, mCarPropertyService);CarLocalServices.addService(CarUserService.class, mCarUserService);CarLocalServices.addService(CarTrustedDeviceService.class, mCarTrustedDeviceService);CarLocalServices.addService(CarUserNoticeService.class, mCarUserNoticeService);CarLocalServices.addService(SystemInterface.class, mSystemInterface);CarLocalServices.addService(CarDrivingStateService.class, mCarDrivingStateService);CarLocalServices.addService(PerUserCarServiceHelper.class, mPerUserCarServiceHelper);CarLocalServices.addService(FixedActivityService.class, mFixedActivityService);CarLocalServices.addService(VmsBrokerService.class, mVmsBrokerService);CarLocalServices.addService(CarOccupantZoneService.class, mCarOccupantZoneService);CarLocalServices.addService(AppFocusService.class, mAppFocusService);// Be careful with order. Service depending on other service should be inited later.ListCarServiceBase allServices new ArrayList();allServices.add(mFeatureController);allServices.add(mCarUserService);allServices.add(mSystemActivityMonitoringService);// 将电源服务添加到Car服务List中-----------------------------allServices.add(mCarPowerManagementService);allServices.add(mCarPropertyService);allServices.add(mCarDrivingStateService);allServices.add(mCarOccupantZoneService);allServices.add(mCarUXRestrictionsService);addServiceIfNonNull(allServices, mOccupantAwarenessService);allServices.add(mCarPackageManagerService);allServices.add(mCarInputService);allServices.add(mGarageModeService);addServiceIfNonNull(allServices, mCarUserNoticeService);allServices.add(mAppFocusService);allServices.add(mCarAudioService);allServices.add(mCarNightService);allServices.add(mFixedActivityService);allServices.add(mInstrumentClusterService);allServices.add(mSystemStateControllerService);allServices.add(mPerUserCarServiceHelper);allServices.add(mCarBluetoothService);allServices.add(mCarProjectionService);addServiceIfNonNull(allServices, mCarDiagnosticService);addServiceIfNonNull(allServices, mCarStorageMonitoringService);allServices.add(mCarConfigurationService);addServiceIfNonNull(allServices, mVmsBrokerService);allServices.add(mCarTrustedDeviceService);allServices.add(mCarMediaService);allServices.add(mCarLocationService);allServices.add(mCarBugreportManagerService);allServices.add(mCarWatchdogService);// Always put mCarExperimentalFeatureServiceController in last.addServiceIfNonNull(allServices, mCarExperimentalFeatureServiceController);mAllServices allServices.toArray(new CarServiceBase[allServices.size()]);}
}CarPower服务启动后会注册成为PowerHalService的监听者。并主动发出WAIT_FOR_VHALL初始状态告知CarPower的监听者并取一下当前的屏幕亮度发送给VHAL。并连接Native层的CarPowerPolicyService来初始化电源管理政策。
// packages/services/Car/service/src/com/android/car/CarPowerManagementService.java/*** Power Management service class for cars. Controls the power states and interacts with other* parts of the system to ensure its own state.*/
public class CarPowerManagementService extends ICarPower.Stub implementsCarServiceBase, PowerHalService.PowerEventListener {public CarPowerManagementService(Context context, PowerHalService powerHal,SystemInterface systemInterface, CarUserService carUserService) {this(context, context.getResources(), powerHal, systemInterface, UserManager.get(context),carUserService, new InitialUserSetter(context,(u) - carUserService.setInitialUser(u),context.getString(R.string.default_guest_name)),IVoiceInteractionManagerService.Stub.asInterface(ServiceManager.getService(Context.VOICE_INTERACTION_MANAGER_SERVICE)));}VisibleForTestingpublic CarPowerManagementService(Context context, Resources resources, PowerHalService powerHal,SystemInterface systemInterface, UserManager userManager, CarUserService carUserService,InitialUserSetter initialUserSetter,IVoiceInteractionManagerService voiceInteractionService) {mContext context;mHal powerHal;mSystemInterface systemInterface;mUserManager userManager;mDisableUserSwitchDuringResume resources.getBoolean(R.bool.config_disableUserSwitchDuringResume);mShutdownPrepareTimeMs resources.getInteger(R.integer.maxGarageModeRunningDurationInSecs) * 1000;mSwitchGuestUserBeforeSleep resources.getBoolean(R.bool.config_switchGuestUserBeforeGoingSleep);if (mShutdownPrepareTimeMs MIN_MAX_GARAGE_MODE_DURATION_MS) {Slog.w(TAG,maxGarageModeRunningDurationInSecs smaller than minimum required, resource: mShutdownPrepareTimeMs (ms) while should exceed: MIN_MAX_GARAGE_MODE_DURATION_MS (ms), Ignore resource.);mShutdownPrepareTimeMs MIN_MAX_GARAGE_MODE_DURATION_MS;}mUserService carUserService;mInitialUserSetter initialUserSetter;mVoiceInteractionManagerService voiceInteractionService;mWifiManager context.getSystemService(WifiManager.class);mWifiStateFile new AtomicFile(new File(mSystemInterface.getSystemCarDir(), WIFI_STATE_FILENAME));}
}Override
public void init() {mPolicyReader.init();mPowerComponentHandler.init();mHal.setListener(this);if (mHal.isPowerStateSupported()) {// 发出初始化状态-------------------------------------------// Initialize CPMS in WAIT_FOR_VHAL stateonApPowerStateChange(CpmsState.WAIT_FOR_VHAL, CarPowerStateListener.WAIT_FOR_VHAL);} else {Slogf.w(TAG, Vehicle hal does not support power state yet.);onApPowerStateChange(CpmsState.ON, CarPowerStateListener.ON);}// 监控屏幕状态这个函数中会将屏幕亮度发给Vehicle HALmSystemInterface.startDisplayStateMonitoring(this);// 连接Car PowerPolicy服务初始化电源政策connectToPowerPolicyDaemon();
}CarPower启动会立刻向监听者和VehicleHAL发出WAIT_FOR_VHAL这个状态
// packages/services/Car/service/src/com/android/car/power/CarPowerManagementService.java
private void doHandlePowerStateChange() {CpmsState state;synchronized (mLock) {state mPendingPowerStates.peekFirst();mPendingPowerStates.clear();if (state null) {Slogf.e(TAG, Null power state was requested);return;}Slogf.i(TAG, doHandlePowerStateChange: newState%s, state.name());if (!needPowerStateChangeLocked(state)) {return;}// now real power change happens. Whatever was queued before should be all cancelled.releaseTimerLocked();mCurrentState state;}mHandler.cancelProcessingComplete();Slogf.i(TAG, setCurrentState %s, state);CarStatsLogHelper.logPowerState(state.mState);switch (state.mState) {case CpmsState.WAIT_FOR_VHAL:// 处理WAIT_FOR_VHAL状态----------------------------handleWaitForVhal(state);break;case CpmsState.ON:handleOn();break;case CpmsState.SHUTDOWN_PREPARE:handleShutdownPrepare(state);break;case CpmsState.SIMULATE_SLEEP:simulateShutdownPrepare();break;case CpmsState.WAIT_FOR_FINISH:handleWaitForFinish(state);break;case CpmsState.SUSPEND:// Received FINISH from VHALhandleFinish();break;default:// Illegal state// TODO: Throw exception?break;}
}private void handleWaitForVhal(CpmsState state) {int carPowerStateListenerState state.mCarPowerStateListenerState;// TODO(b/177478420): Restore Wifi, Audio, Location, and Bluetooth, if they are artificially// modified for S2R.mSilentModeHandler.querySilentModeHwState();// 给CarPower服务的监听者发送状态sendPowerManagerEvent(carPowerStateListenerState);// Inspect CarPowerStateListenerState to decide which message to send via VHALswitch (carPowerStateListenerState) {case CarPowerStateListener.WAIT_FOR_VHAL:// 通过PowerHAlService向VehicleHAL发送状态mHal.sendWaitForVhal();break;case CarPowerStateListener.SHUTDOWN_CANCELLED:mShutdownOnNextSuspend false; // This cancels the NextSuspendmHal.sendShutdownCancel();break;case CarPowerStateListener.SUSPEND_EXIT:mHal.sendSleepExit();break;}if (mWifiAdjustmentForSuspend) restoreWifi();
}
接下来MCU会给VehicleHAL发送电源通知VehicleHAL通知(AP_POWER_STATE_REQ ON) 给CarPower服务。
Override
public void onHalEvents(ListVehiclePropValue values) {PowerEventListener listener;synchronized (mLock) {if (mListener null) {if (mQueuedEvents null) {mQueuedEvents new LinkedList();}mQueuedEvents.addAll(values);return;}listener mListener;}dispatchEvents(values, listener);
}private void dispatchEvents(ListVehiclePropValue values, PowerEventListener listener) {for (VehiclePropValue v : values) {switch (v.prop) {case AP_POWER_STATE_REPORT:// Ignore this property event. It was generated inside of CarService.break;case AP_POWER_STATE_REQ:// 发送的是这个状态------ AP_POWER_STATE_REQONint state v.value.int32Values.get(VehicleApPowerStateReqIndex.STATE);int param v.value.int32Values.get(VehicleApPowerStateReqIndex.ADDITIONAL);Slog.i(CarLog.TAG_POWER, Received AP_POWER_STATE_REQ powerStateReqName(state) param param);listener.onApPowerStateChange(new PowerState(state, param));break;case DISPLAY_BRIGHTNESS:{int maxBrightness;synchronized (mLock) {maxBrightness mMaxDisplayBrightness;}int brightness v.value.int32Values.get(0) * MAX_BRIGHTNESS / maxBrightness;if (brightness 0) {Slog.e(CarLog.TAG_POWER, invalid brightness: brightness , set to 0);brightness 0;} else if (brightness MAX_BRIGHTNESS) {Slog.e(CarLog.TAG_POWER, invalid brightness: brightness , set to MAX_BRIGHTNESS);brightness MAX_BRIGHTNESS;}Slog.i(CarLog.TAG_POWER, Received DISPLAY_BRIGHTNESS brightness);listener.onDisplayBrightnessChange(brightness);}break;}}
}CarPowerService接收到 AP_POWER_STATE_REQ ON认为当前是电源ON的状态。应用电源策略告知机能模块可以使能、通知观察者电源状态为ON然后向VehicleHAL进行回复也叫report
packages/services/Car/service/src/com/android/car/power/CarPowerManagementService.javaOverride
public void onApPowerStateChange(PowerState state) {synchronized (mLock) {mPendingPowerStates.addFirst(new CpmsState(state));mLock.notify();}// 发给handler在单独的线程中处理。最终调用的是自身的doHandlePowerStateChange函数mHandler.handlePowerStateChange();
}private void doHandlePowerStateChange() {CpmsState state;synchronized (mLock) {state mPendingPowerStates.peekFirst();mPendingPowerStates.clear();if (state null) {Slogf.e(TAG, Null power state was requested);return;}Slogf.i(TAG, doHandlePowerStateChange: newState%s, state.name());if (!needPowerStateChangeLocked(state)) {return;}// now real power change happens. Whatever was queued before should be all cancelled.releaseTimerLocked();mCurrentState state;}mHandler.cancelProcessingComplete();Slogf.i(TAG, setCurrentState %s, state);CarStatsLogHelper.logPowerState(state.mState);switch (state.mState) {case CpmsState.WAIT_FOR_VHAL:handleWaitForVhal(state);break;case CpmsState.ON:// 处理电源ON----------------------------------------------------------------handleOn();break;case CpmsState.SHUTDOWN_PREPARE:handleShutdownPrepare(state);break;case CpmsState.SIMULATE_SLEEP:simulateShutdownPrepare();break;case CpmsState.WAIT_FOR_FINISH:handleWaitForFinish(state);break;case CpmsState.SUSPEND:// Received FINISH from VHALhandleFinish();break;default:// Illegal state// TODO: Throw exception?break;}
}VisibleForTesting
void handleOn() {if (factoryResetIfNeeded()) return;// If current user is a Guest User, we want to inform CarUserNoticeService not to show// notice for current user, and show user notice only for the target user.if (!mSwitchGuestUserBeforeSleep) {updateCarUserNoticeServiceIfNecessary();}boolean isPreemptive;synchronized (mLock) {isPreemptive mPolicyReader.isPreemptivePowerPolicy(mCurrentPowerPolicyId);}if (!mSilentModeHandler.isSilentMode() isPreemptive) {cancelPreemptivePowerPolicy();} else {// 应用电源策略---------------------------------applyDefaultPowerPolicyForState(VehicleApPowerStateReport.ON,PolicyReader.POWER_POLICY_ID_ALL_ON);}// 通知观察者电源状态为ON------------------------sendPowerManagerEvent(CarPowerStateListener.ON);// 通过PowerHAlServicee回复Vehicle HALVehicleApPowerStateReport.ONmHal.sendOn();synchronized (mLock) {if (mIsBooting) {Slogf.d(TAG, handleOn(): called on boot);mIsBooting false;return;}}try {mUserService.onResume();} catch (Exception e) {Slogf.e(TAG, e, Could not switch user on resume);}
}到这里CarPower主要的开机处理流程完毕。实际上可以看出来主要是接收Vehicle HAl Event包括回复VehicleHAL状态告知监听者电源状态、应用电源政策使能相关机能。并且在启动阶段取了一下当前的屏幕亮度告知VehicleHAL最终是告知MCU。当然还有一些其他的处理比如用户服务的恢复有兴趣的可以读一下这部分代码。CarPowerService上电时序图。
