Android Camera2 HAL3 高通Qualcomm Camera底层openCamera代码流程
本文列出代码调用流程，作为参考，要想了解高通驱动架构需要结核实际理解代码，不要一味的沉浸在代码中，这样是没有任何效果的。
openCamera
/*openCamera_flow*/
#if 1
/*************************openCamera_flow_start******************************************************************/
QCamera2Factory.cpp
struct hw_module_methods_t QCamera2Factory::mModuleMethods = {
.open = QCamera2Factory::camera_device_open,
};
QCamera2Factory.cpp
int QCamera2Factory::camera_device_open(const struct hw_module_t *module, const char *id,struct hw_device_t **hw_device)
rc = gQCamera2Factory->cameraDeviceOpen(atoi(id), hw_device);
int QCamera2Factory::cameraDeviceOpen(int camera_id,struct hw_device_t **hw_device)
if(CAMERA_DEVICE_API_VERSION_3_0)
QCamera3HardwareInterface *hw = new QCamera3HardwareInterface(mHalDescriptors[camera_id].cameraId,mCallbacks);
mCameraId(cameraId),/* 传入cameraID*/
mCallbacks(callbacks),/* camera_module_callbacks_t */
mCameraDevice.common.close = close_camera_device;/* 关闭相机回调设置 */
mCameraDevice.ops = &mCameraOps;/* 设置关键的回调函数 */
mCameraDevice.priv = this;
gCamCapability[cameraId]->version = CAM_HAL_V3;
rc = hw->openCamera(hw_device);/* QCamera3HWI.cpp openCamera(struct hw_device_t **hw_device) */
QCamera3HWI.cpp
int QCamera3HardwareInterface::openCamera(struct hw_device_t **hw_device)
mPerfLockMgr.acquirePerfLock(PERF_LOCK_OPEN_CAMERA);
LOGI("[KPI Perf]: E PROFILE_OPEN_CAMERA camera id %d",mCameraId);
/*有一个代码块，这里： */
{ rc = mQCamera3HdrPlusListenerThread->run("QCamera3HdrPlusListenerThread"); }
rc = openCamera();
QCamera3HWI.cpp int QCamera3HardwareInterface::openCamera()
rc = QCameraFlash::getInstance().reserveFlashForCamera(mCameraId);/*?*/
rc = camera_open((uint8_t)mCameraId, &mCameraHandle);/* mCameraId 在当前类初始化设置 ，设置mCameraHandle*/
int32_t camera_open(uint8_t camera_idx, mm_camera_vtbl_t **camera_vtbl)/* camera_vtbl mm_camera_interface.c */
if(is_dual_camera_by_idx(camera_idx))/*判断是否是多相机*/
is_multi_camera = 1; /* 设置多相机标志 */
cam_idx = mm_camera_util_get_handle_by_num(0,g_cam_ctrl.cam_index[camera_idx]);/*主摄像机*/
aux_idx = (get_aux_camera_handle(g_cam_ctrl.cam_index[camera_idx]);/*辅助摄像机*/
/* 如果上面成功了，则执行 创建相机对象 */
/* initialize camera obj 这个是主摄像机 */
cam_obj = (mm_camera_obj_t *)malloc(sizeof(mm_camera_obj_t));
cam_obj->ctrl_fd = -1;
cam_obj->ds_fd = -1;
cam_obj->ref_count++;
cam_obj->my_num = 0;/*根据这个确认相机dev 名称当辅助相机时这个 = 1*/
cam_obj->my_hdl = mm_camera_util_generate_handler(cam_idx);/*/* 生成相机句柄 */
cam_obj->vtbl.camera_handle = cam_obj->my_hdl; /* set 相机 handler */
cam_obj->vtbl.ops = &mm_camera_ops;/* 跳转到 mm_camera_interface.c */
rc = mm_camera_open(cam_obj);/* 打开相机 mm_camera.c 进入kernel open("/dev/video...")*/
int32_t mm_camera_open(mm_camera_obj_t *my_obj)
mm_camera_util_get_dev_name_by_num()/*my_hdl 和my_num 获取相机设备的名称字符串*/
my_obj->ctrl_fd = open(dev_name, O_RDWR | O_NONBLOCK);/*打开相机*/
mm_camera_get_session_id(my_obj, &my_obj->sessionid);/*设置sessionID*/
int32_t mm_camera_get_session_id(mm_camera_obj_t *my_obj,uint32_t* sessionid)
control.id = MSM_CAMERA_PRIV_G_SESSION_ID;
control.value = value;
rc = ioctl(my_obj->ctrl_fd, VIDIOC_G_CTRL, &control);/*获取控制权*/
value = control.value;
*sessionid = value;/* 将这个值付给 sessionid */
/*************************************************************
如果守护进程存在 还有其他操作,这里时deamon进程的设置
**************************************************************/
mm_camera_cmd_thread_launch(&my_obj->evt_thread,mm_camera_dispatch_app_event,(void *)my_obj);
/* launch event poll thread we will add evt fd into event poll thread upon user first register for evt */
LOGD("Launch evt Poll Thread in Cam Open");
snprintf(my_obj->evt_poll_thread.threadName, THREAD_NAME_SIZE, "CAM_evntPoll");
mm_camera_poll_thread_launch(&my_obj->evt_poll_thread,MM_CAMERA_POLL_TYPE_EVT);
mm_camera_evt_sub(my_obj, TRUE);
if(is_multi_camera)/* 如果是多相机 还要再打开辅助相机 */
rc = mm_camera_muxer_camera_open(aux_idx, cam_obj);
int32_t mm_camera_muxer_camera_open(uint8_t cam_idx,mm_camera_obj_t *cam_obj)/*mm_camera_muxer.c*/
/* initialize camera obj 辅助相机 */
memset(my_obj, 0, sizeof(mm_camera_obj_t));
my_obj->ctrl_fd = -1;
my_obj->ds_fd = -1;
my_obj->ref_count++;
my_obj->my_num = my_num; /* 函数开始定义了 uint8_t my_num = 1; 辅助相机 */
my_obj->my_hdl = mm_camera_util_generate_handler_by_num(my_num, cam_idx);/* 生成相机句柄 */
rc = mm_camera_open(my_obj);/* 打开辅助相机,和主相机操作一样 */
LOGD("Open succeded\n");/*当打开成功后，再组织主摄像头和辅助摄像头的关系*/
rc = mm_camera_util_set_camera_object(cam_idx, my_obj);
my_obj->vtbl.camera_handle = (cam_obj->my_hdl | my_obj->my_hdl);
cam_obj->vtbl.camera_handle = my_obj->vtbl.camera_handle;
cam_obj->aux_cam_obj[cam_obj->num_s_cnt++] = my_obj;
my_obj->master_cam_obj = cam_obj;
cam_obj->master_cam_obj = NULL;/*？？*/
g_cam_ctrl.cam_obj[cam_idx] = cam_obj;/*设置相机obj*/
*camera_vtbl = &cam_obj->vtbl; /* 主要设置：mCameraHandle->ops，用来跳转到 mm_camera_interface.c */
rc = mCameraHandle->ops->register_event_notify(mCameraHandle->camera_handle, camEvtHandle, (void *)this);/*camEvtHandle*/
static int32_t mm_camera_intf_register_event_notify(camera_handle,evt_cb,void * user_data)/*mm_camera_interface.c */
uint32_t handle = get_main_camera_handle(camera_handle);/* get_main_camera_handle */
uint32_t get_main_camera_handle(uint32_t handle)
return mm_camera_util_get_handle_by_num(0, handle);
uint32_t mm_camera_util_get_handle_by_num(uint8_t cam_num, uint32_t handler)
(handler & (MM_CAMERA_HANDLE_BIT_MASK << (MM_CAMERA_HANDLE_SHIFT_MASK * cam_num)));/*16 0x0000ffff*/
uint32_t aux_handle = get_aux_camera_handle(camera_handle);/* get_aux_camera_handle */
uint32_t get_aux_camera_handle(uint32_t handle)
return mm_camera_util_get_handle_by_num(1, handle);
uint32_t mm_camera_util_get_handle_by_num(uint8_t cam_num, uint32_t handler)
(handler & (MM_CAMERA_HANDLE_BIT_MASK <<(MM_CAMERA_HANDLE_SHIFT_MASK * cam_num)))/*16 0x0000ffff*/
if (handle)/*主摄像机 mm_camera_interface.c */
my_obj = mm_camera_util_get_camera_by_handler(handle);
mm_camera_obj_t* mm_camera_util_get_camera_by_handler(uint32_t cam_handle)
for (cam_idx = 0; cam_idx < MM_CAMERA_MAX_NUM_SENSORS; cam_idx++)/* 根据打开摄像头的填入方式再取出来 */
if ((NULL != g_cam_ctrl.cam_obj[cam_idx]) && (cam_handle == (uint32_t)g_cam_ctrl.cam_obj[cam_idx]->my_hdl)) {
cam_obj = g_cam_ctrl.cam_obj[cam_idx];/*(uint32_t)g_cam_ctrl.cam_obj[cam_idx]->my_hdl 确认主相机和辅助相机*/
rc = mm_camera_register_event_notify(my_obj, evt_cb, user_data);/* evt_cb == QCamera3HardwareInterface::camEvtHandle */
/* 给取出来的相机设置回调函数 */
mm_camera_register_event_notify_internal(my_obj,evt_cb,user_data);/*mm_camera.c*/
int32_t mm_camera_register_event_notify_internal(mm_camera_obj_t *my_obj,mm_camera_event_notify_t evt_cb,void * user_data)
evt_array = &my_obj->evt;
if(evt_cb)/* this is reg case */
{
for(i = 0; i < MM_CAMERA_EVT_ENTRY_MAX; i++)
if(evt_array->evt[i].user_data == NULL)
evt_array->evt[i].evt_cb = evt_cb;
evt_array->evt[i].user_data = user_data;/* QCamera3HardwareInterface 对象 */
evt_array->reg_count++;
}else /* this is unreg case */
{
for(i = 0; i < MM_CAMERA_EVT_ENTRY_MAX; i++)
if(evt_array->evt[i].user_data == user_data)
evt_array->evt[i].evt_cb = NULL;
evt_array->evt[i].user_data = NULL;
evt_array->reg_count--;
}
if (aux_handle)/*辅助摄像机 mm_camera_interface.c */
my_obj = mm_camera_util_get_camera_head(aux_handle);
mm_camera_obj_t* mm_camera_util_get_camera_head(uint32_t cam_handle)
cam_obj = mm_camera_util_get_camera_by_handler(cam_handle);/* 跟主摄像机一样 */
rc = mm_camera_muxer_register_event_notify(aux_handle,evt_cb, user_data, my_obj);/* evt_cb == QCamera3HardwareInterface::camEvtHandle */
int32_t mm_camera_muxer_register_event_notify(uint32_t camera_handle,mm_camera_event_notify_t evt_cb,void *user_data, mm_camera_obj_t *cam_obj)
my_obj = mm_muxer_util_get_camera_by_obj(camera_handle, cam_obj);/*mm_camera_muxer.c*/
mm_camera_obj_t* mm_muxer_util_get_camera_by_obj(uint32_t cam_handle,mm_camera_obj_t *cam_obj)
if (cam_handle == cam_obj->my_hdl)
return cam_obj;
if (obj->master_cam_obj != NULL)
obj = obj->master_cam_obj;
for (i = 0; i < obj->num_s_cnt; i++)/*遍历相机*/
if (cam_handle == obj->aux_cam_obj[i]->my_hdl)
obj = obj->aux_cam_obj[i];
rc = mm_camera_register_event_notify(my_obj, evt_cb, user_data); /*跟主摄像机一样 evt_cb == QCamera3HardwareInterface::camEvtHandle */
rc = mCameraHandle->ops->get_session_id(mCameraHandle->camera_handle,&sessionId[mCameraId]);
static int32_t mm_camera_intf_get_session_id(uint32_t camera_handle,uint32_t* sessionid)/*mm_camera_interface.c*/
uint32_t handle = get_main_camera_handle(camera_handle);
uint32_t aux_handle = get_aux_camera_handle(camera_handle);
if (handle)
my_obj = mm_camera_util_get_camera_by_handler(handle);/*同上*/
*sessionid = my_obj->sessionid;
else if (aux_handle)/*？？？为什么是else if因为是存在一个线程中，因此是循环执行 */
my_obj = mm_camera_util_get_camera_head(aux_handle);/*同上*/
rc = mm_camera_muxer_get_session_id(aux_handle, sessionid, my_obj);
int32_t mm_camera_muxer_get_session_id(uint32_t camera_handle,uint32_t* sessionid, mm_camera_obj_t *cam_obj)
my_obj = mm_muxer_util_get_camera_by_obj(camera_handle, cam_obj);
if(my_obj)
*sessionid = my_obj->sessionid;
rc = mCameraHandle->ops->map_buf() /* 映射内存mmap方式，这里相当于是一个内存池，Map memory for related cam sync buffer mm_camera_interface.c*/
static int32_t mm_camera_intf_map_buf(uint32_t camera_handle,uint8_t buf_type, int fd, size_t size, void *buffer)
uint32_t handle = get_main_camera_handle(camera_handle);
uint32_t aux_handle = get_aux_camera_handle(camera_handle);
if (handle)
my_obj = mm_camera_util_get_camera_by_handler(handle);
if(my_obj)
rc = mm_camera_map_buf(my_obj, buf_type, fd, size, buffer);
else if (aux_handle)/*？？？为什么是else if因为是存在一个线程中，因此是循环执行 */
my_obj = mm_camera_util_get_camera_head(aux_handle);
if(my_obj)
rc = mm_camera_muxer_map_buf(aux_handle, buf_type,fd, size, buffer, my_obj);
m_pDualCamCmdPtr =(cam_dual_camera_cmd_info_t*) DATA_PTR(m_pDualCamCmdHeap,0);
if(rc == 0)
*hw_device = &mCameraDevice.common; /* 版本、close方法 module->methods->open */
/* 后置相机 0 前置相机 1 */
LOGI("[KPI Perf]: X PROFILE_OPEN_CAMERA camera id %d, rc: %d",mCameraId, rc);
/*************************openCamera_flow_end******************************************************************/
#endif