和你一起终身学习，这里是程序员Android

经典好文推荐，通过阅读本文，您将收获以下知识点:

一、架构介绍
二、Camera Open流程（Hal-Sensor）
三、Sensor Search流程

一、架构介绍

1.1 Camera的框架分为Kernel部分和Hal部分

Kernel部分：

image sensor driver——负责具体型号的sensor的id检测，上电，以及在preview、capture、初始化、3A等等功能设定时的寄存器配置；
ISP driver——通过DMA将sensor数据流上传；
Hal部分：

imageio——主要负责数据buffer上传的pipe；
drv——包含imgsensor和isp的hal层控制；
feature io——包含各种3A等性能配置；
来看一张图，大致来了解一下Camera的整体架构。

1.2 MiddleWare(MW)层

ICameraProvider——向上暴露的接口调用，实现是在CameraProvider中；
Device@3.2ICameraDevice——用于Camera Service去操作各个Camera device的操作，实现在CameraDevice3中；
Device@3.2ICameraDeviceSession——Camera会话的接口；
ICameraDeviceCallBack——底层对上层的CallBack接口；
CameraDeviceManager——用于管理CameraDevice，包括查找，打开，关闭等。

1.3 Pipeline介绍

PipelineModel是HAL3核心架构，对上需要开放对Pipeline创建 / 操作的API，对下需要建立Pipeline / 管理Pipeline的生命周期。
PipelineModel会针对不同的场景创建不同的Pipeline和HWNode，HWNode向下传输APP层的命令，向上传递图形数据。

P1Node——pipeline的root node，input app命令，output raw data to P2CaptureNode and P2StreamNode；
P2CaptureNode——转换raw data to yuv，Support scale/crop；
P2StreamingNode——和P2CaptureNode功能类似；
JPEGNode——Convert YUV to Jpeg；
FDNode——Generate the FD information；

二、Camera Open流程（Hal-Sensor）

在APP层调用openCamera后会调用的CameraDevice层，最后调用到driver中，整体的调用流程如下：

先从CameraDevice3SessionImpl的open函数分析。

//vendor/mediatek/proprietary/hardware/mtkcam3/main/hal/device/3.x/device/CameraDevice3SessionImpl.cppauto ThisNamespace::open(const ::android::sp<V3_4::ICameraDeviceCallback>& callback) -> ::android::status_t{auto pDeviceManager = mStaticInfo.mDeviceManager;auto const& instanceName = mStaticInfo.mStaticDeviceInfo->mInstanceName;status = pDeviceManager->startOpenDevice(instanceName);err = onOpenLocked(callback);pDeviceManager->updatePowerOnDone();status = pDeviceManager->finishOpenDevice(instanceName, false/*cancel*/);}auto ThisNamespace::onOpenLocked(const ::android::sp<V3_4::ICameraDeviceCallback>& callback) -> ::android::status_t{//--------------------------------------------------------------------------{Mutex::Autolock _l(mPipelineModelLock);auto pPipelineModelMgr = IPipelineModelManager::get();auto pPipelineModel = pPipelineModelMgr->getPipelineModel( getInstanceId() );::android::status_t err = OK;err = pPipelineModel->open(getInstanceName().c_str(), this);mPipelineModel = pPipelineModel;}//--------------------------------------------------------------------------return OK;}

//vendor/mediatek/proprietary/hardware/mtkcam3/pipeline/model/PipelineModelImpl.cpp

auto PipelineModelImpl::open(std::string const& userName,android::wp<IPipelineModelCallback> const& callback) -> int{{std::lock_guard<std::timed_mutex> _l(mLock);mUserName = userName;mCallback = callback;mvOpenFutures.push_back(std::async(std::launch::async,[this]() {return CC_LIKELY( mHalDeviceAdapter!=nullptr )&& CC_LIKELY( mHalDeviceAdapter->open() ) //android::sp<IHalDeviceAdapter> const    mHalDeviceAdapter;&& CC_LIKELY( mHalDeviceAdapter->powerOn() );})); }return OK;}

调用mHalDeviceAdapter的open用于初始化DeviceAdapter，这里重点看powerOn函数，这里的powerOn有另起一个线程去操作sensor，等待sensor上电完成后对3A进行powerOn操作。

//vendor/mediatek/proprietary/hardware/mtkcam3/pipeline/model/adapter/HalDeviceAdapter.cpp

virtual auto powerOn() -> bool override{//1.调用HalSensor的powerOnstd::future<bool> future_initSensor =std::async(std::launch::async,[ this ]() {if (CC_UNLIKELY( !mvHalSensor[i]->powerOn(mName.c_str(), 1, &sensorIndex) ))}//2.init 3A and poweron 3Abool success_sensorPowerOn = false;bool success_init3A = true;for (size_t i = 0; i < mvPhySensorId.size(); i++){mvHal3A.push_back(IHal3AAdapter::create(mvPhySensorId[i], mName.c_str()));mvHalIsp.push_back(MAKE_HalISP(mvPhySensorId[i], mName.c_str()));}//3.Wait for Sensor PowerOn{success_sensorPowerOn = future_initSensor.get();if  ( ! success_sensorPowerOn ) {return false;}}//4.Notify 3A of Power Onfor (size_t i = 0; i < mvHal3A.size(); i++){if (mvHal3A[i] != nullptr){mvHal3A[i]->notifyPowerOn();}}}

这里继续跟踪mvHalSensor[i]->powerOn，会调用到HalSensor.cpp中，这里到了和Driver交互的部分：

初始化SeninfDrv和SensorDrv；
setSensorMclk和setSensorMclkDrivingCurrent；
最后通过mpSensorDrv->open；
//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensor.cpp

MBOOL HalSensor:: powerOn(){mpSeninfDrv->init();mpSensorDrv->init();for (MUINT i = 0; i < uCountOfIndex; i++){setSensorMclk(sensorIdx, 1)setSensorMclkDrivingCurrent(sensorIdx)// Open sensor, try to open 3 timefor (int i =0; i < 3; i++) {if ((ret = mpSensorDrv->open(sensorIdx)) != SENSOR_NO_ERROR) {MY_LOGE("pSensorDrv->open fail, retry = %d ", i);}}}}

接下来会调用到imgsensor_drv的open函数，到此featureControl调用到驱动的SENSOR_FEATURE_OPEN。

//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/imgsensor_drv.cpp

MINT32
ImgSensorDrv::open(IMGSENSOR_SENSOR_IDX sensorIdx){MUINT32                           featureParaLen = sizeof(MUINT32);MUINT32                           featurePara;return featureControl(sensorIdx, SENSOR_FEATURE_OPEN, (MUINT8 *)&featurePara, &featureParaLen);}MINT32  ImgSensorDrv::featureControl(IMGSENSOR_SENSOR_IDX sensorIdx,ACDK_SENSOR_FEATURE_ENUM FeatureId,MUINT8 *pFeaturePara,MUINT32 *pFeatureParaLen){ACDK_SENSOR_FEATURECONTROL_STRUCT featureCtrl;//结构ACDK_SENSOR_FEATURECONTROL_STRUCT和kernel中一致featureCtrl.InvokeCamera = sensorIdx;featureCtrl.FeatureId = FeatureId;//SENSOR_FEATURE_SET_DRIVERfeatureCtrl.pFeaturePara = pFeaturePara;featureCtrl.pFeatureParaLen = pFeatureParaLen;if (ioctl(m_fdSensor, KDIMGSENSORIOC_X_FEATURECONCTROL , &featureCtrl) < 0) {LOG_ERR("[featureControl] Err-ctrlCode (%s)", strerror(errno));return -errno;}return SENSOR_NO_ERROR;}

三、Sensor Search流程

CameraService是在开机时启动的，启动后进行searchSensor的操作，会search系统有多少camera，开机时的search操作，只进行camera支持数量的遍历，以及sensor ID的读取操作。

HalSensorList：
vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensorList.enumList.cpp
vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensorList.cpp

SeninfDrv：
vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/mt6765/seninf_drv.cpp

SensorDrv：
vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/imgsensor_drv.cpp

//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensorList.cpp

MUINT
HalSensorList::searchSensors(){Mutex::Autolock _l(mEnumSensorMutex);MY_LOGD("searchSensors");return  enumerateSensor_Locked();}MUINT
HalSensorList::queryNumberOfSensors() const{Mutex::Autolock _l(mEnumSensorMutex);return  mEnumSensorList.size();}IMetadata const&HalSensorList::queryStaticInfo(MUINT const index) const{EnumInfo const* pInfo = queryEnumInfoByIndex(index);MY_LOGF_IF(pInfo==NULL, "NULL EnumInfo for sensor %d", index);return  pInfo->mMetadata;}

searchSensors()会调用enumerateSensor_Locked()。

//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensorList.enumList.cpp

MUINT HalSensorList::enumerateSensor_Locked(){SensorDrv *const pSensorDrv = SensorDrv::get();SeninfDrv *const pSeninfDrv = SeninfDrv::createInstance();//初始化seninf,配置ISP相关内容pSeninfDrv->init();//将所有的clk全部打开pSeninfDrv->setAllMclkOnOff(ISP_DRIVING_8MA, TRUE);pSensorDrv->init();for (MUINT i = IMGSENSOR_SENSOR_IDX_MIN_NUM; i <= max_index_of_camera; i++) {if((ret = pSensorDrv->searchSensor((IMGSENSOR_SENSOR_IDX)i)) == SENSOR_NO_ERROR){//query sensorinfoquerySensorDrvInfo((IMGSENSOR_SENSOR_IDX)i);//fill in metadatabuildSensorMetadata((IMGSENSOR_SENSOR_IDX)i);pSensorInfo = pSensorDrv->getSensorInfo((IMGSENSOR_SENSOR_IDX)i);addAndInitSensorEnumInfo_Locked((IMGSENSOR_SENSOR_IDX)i,mapToSensorType(pSensorInfo->GetType()),pSensorInfo->getDrvMacroName());}}     }

下面看下pSensorDrv->getSensorInfo的流程，这里有去获取sensorList的内容。

//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/imgsensor_drv.cpp

MINT32 ImgSensorDrv::searchSensor(IMGSENSOR_SENSOR_IDX sensorIdx){GetSensorInitFuncList(&pSensorInitFunc);featureControl(sensorIdx, SENSOR_FEATURE_SET_DRIVER, (MUINT8 *)&idx, &featureParaLen);NSFeature::SensorInfoBase* pSensorInfo = pSensorInitFunc[idx].pSensorInfo;}

（A）GetSensorInitFuncList是获取到配置的sensorList的内容，此sensorList需要与kernel层配置的一致，不一致的话在打开camera时会出现异常。

//vendor/mediatek/proprietary/custom/mtxxxx/hal/imgsensor_src/sensorlist.cpp

MSDK_SENSOR_INIT_FUNCTION_STRUCT SensorList[] ={/*IMX*/#if defined(IMX586_MIPI_RAW)RAW_INFO_M(IMX586_SENSOR_ID, DEFAULT_MODULE_INDEX, DEFAULT_MODULE_ID, SENSOR_DRVNAME_IMX586_MIPI_RAW, CAM_CALGetCalData),#endif#if defined(IMX519_MIPI_RAW)RAW_INFO_M(IMX519_SENSOR_ID, DEFAULT_MODULE_INDEX, DEFAULT_MODULE_ID, SENSOR_DRVNAME_IMX519_MIPI_RAW, CAM_CALGetCalData),#endif//...};UINT32 GetSensorInitFuncList(MSDK_SENSOR_INIT_FUNCTION_STRUCT **ppSensorList){if (NULL == ppSensorList) {ALOGE("ERROR: NULL pSensorList\n");return MHAL_UNKNOWN_ERROR;}*ppSensorList = &SensorList[0];return MHAL_NO_ERROR;}

（B）featureControl的setDriver流程同上面的一致。

原文链接：https://blog.csdn.net/dongxianfei/article/details/121382327

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