Mtk Camera Hal到驱动的流程（1）

（1）架构介绍

（A）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。

（B）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。

（C）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；

（2）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：

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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.cppauto 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.cppvirtual 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;
}

（3）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

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//vendor/mediatek/proprietary/hardware/mtkcam/drv/src/sensor/common/v1/HalSensorList.cppMUINT
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.cppMUINT 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.cppMSDK_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。