分析vivi.c

static int __init vivi_init(void)struct vb2_queue *q;/* 找到支持的字体格式 */const struct font_desc *font = find_font("VGA8x16");/* 创建一个实例 */ret = vivi_create_instance//用于管理v4l2_ctrl，亮度，音量等属性信息就是用v4l2_ctrl来表示的struct v4l2_ctrl_handler *hdl;/* 封装的结构体 */struct vivi_dev *dev;/* 摄像头的结构体 */struct video_device *vfd;dev = kzalloc(sizeof(*dev), GFP_KERNEL);//对video_device进行赋值，里面有要回调的方法集*vfd = vivi_template;//初始化v4l2_ctrl_handlerv4l2_ctrl_handler_init(hdl, 11);//根据ID(V4L2_CID_AUDIO_VOLUME)添加一个新的标准属性dev->volume = v4l2_ctrl_new_std(hdl, &vivi_ctrl_ops,V4L2_CID_AUDIO_VOLUME, 0, 255, 1, 200);v4l2_ctrl_new(hdl, ops, id, name, type,min, max, step, def, flags, NULL, NULL);struct v4l2_ctrl *ctrl;ctrl = kzalloc(sizeof(*ctrl) + sz_extra, GFP_KERNEL);/* 初始化和设置v4l2_ctrl */INIT_LIST_HEAD(&ctrl->node);INIT_LIST_HEAD(&ctrl->ev_subs);ctrl->handler = hdl;ctrl->ops = ops;ctrl->id = id;//添加到v4l2_ctrl_handler尾部list_add_tail(&ctrl->node, &hdl->ctrls);//添加自定义的v4l2_ctrldev->button = v4l2_ctrl_new_custom(hdl, &vivi_ctrl_button, NULL);/*那么什么时候用v4l2_ctrl呢？是在应用层调用ioctl时根据不同的命令码在__video_do_ioctl中调用不同的v4l2_ctrl*//* 对dev->v4l2_dev简单的初始化 */ret = v4l2_device_register(NULL, &dev->v4l2_dev);/* 对vb2_queue初始化 */q = &dev->vb_vidq;q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF | VB2_READ;q->drv_priv = dev;q->buf_struct_size = sizeof(struct vivi_buffer);q->ops = &vivi_video_qops;q->mem_ops = &vb2_vmalloc_memops;q->timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;/* vivi_dev中包含v4l2_dev和video_device，video_device包含v4l2_dev，video_device指向v4l2_dev */vfd = &dev->vdev;/* 提供操作方法集 */*vfd = vivi_template;vfd->debug = debug;vfd->v4l2_dev = &dev->v4l2_dev;vfd->queue = q;set_bit(V4L2_FL_USE_FH_PRIO, &vfd->flags);/* 将vivi_dev放入video_device中的dev中的私有数据中 */video_set_drvdata(vfd, dev);ret = video_register_device(vfd, VFL_TYPE_GRABBER, video_nr);__video_register_device(vdev, type, nr, 1, vdev->fops->owner);/* 设置名字 */case VFL_TYPE_GRABBER:name_base = "video";/* video的次设备号从0到64 */case VFL_TYPE_GRABBER:minor_offset = 0;minor_cnt = 64;/* 将注册的video_device放入全局video_device中 */video_device[vdev->minor] = vdev;/* 初始化字符设备那一套 */vdev->cdev = cdev_alloc();/* 初始化操作方法集，这个操作操作方法集是上层调用的 */vdev->cdev->ops = &v4l2_fops;cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);/* 创建类，属性文件等 */.......APP：openstatic const struct file_operations v4l2_fops = {.open = v4l2_open,/* 根据此设备号找到video_device */vdev = video_devdata(filp);video_device[iminor(file_inode(file))];/* 调用video_device中操作方法集中的open */if (vdev->fops->open) {if (video_is_registered(vdev))ret = vdev->fops->open(filp);/* 回调video_device中操作方法集中的open */ v4l2_fh_openstruct video_device *vdev = video_devdata(filp);video_device[iminor(file_inode(file))];struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);filp->private_data = fh;if (fh == NULL)return -ENOMEM;v4l2_fh_init(fh, vdev);v4l2_fh_add(fh);APP：read 同open重点是ioctlstatic const struct file_operations v4l2_fops = {.unlocked_ioctl = v4l2_ioctl,struct video_device *vdev = video_devdata(filp);ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);/* 回调video_device中操作方法集中的ioctl */static const struct v4l2_file_operations vivi_fops = {return video_usercopy(file, cmd, arg, __video_do_ioctl);err = func(file, cmd, parg);/* 回调__video_do_ioctl函数 */__video_do_ioctlstruct video_device *vfd = video_devdata(file);/* 获得video_device中的ioctl_ops */const struct v4l2_ioctl_ops *ops = vfd->ioctl_ops;/* 根据cmd从v4l2_ioctl_info数组中取出相应的v4l2_ioctl_info */if (v4l2_is_known_ioctl(cmd)) {info = &v4l2_ioctls[_IOC_NR(cmd)];/* 调用cmd对应的函数 */ret = info->u.func(ops, file, fh, arg);case VIDIOC_S_CTRL://根据不同的命令码应用层传进来的arg类型也是不同的，arg只是一个指针而已，具体类型需要根据命令码来转换struct v4l2_control *p = arg;if (vfd->ctrl_handler) {ret = v4l2_s_ctrl(NULL, vfd->ctrl_handler, p);//根据命令码找到v4l2_ctrl，因为v4l2_ctrl就是之前根据命令码创建出来的struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);以ioctl的参数VIDIOC_STREAMON为例，分析调用过程IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE),当cmd命令为VIDIOC_STREAMON时：调用v4l_streamon函数v4l_streamonconst struct v4l2_ioctl_ops *ops = vfd->ioctl_ops;/* 第一个参数时video_device里的ioctl_ops */static int v4l_streamon(const struct v4l2_ioctl_ops *ops,struct file *file, void *fh, void *arg)ops->vidioc_streamon(file, fh, *(unsigned int *)arg);回调video_device里的ioctl_ops的vidioc_streamonstatic const struct v4l2_ioctl_ops vivi_ioctl_ops = {.vidioc_streamon = vb2_ioctl_streamon,vb2_streamon(vdev->queue, i);vb2_internal_streamon(q, type);list_for_each_entry(vb, &q->queued_list, queued_entry)__enqueue_in_driver(vb);/* 每个vb2_buffer都指向所属的vb2_queue，所有的vb2_buffer通过list_head连接到vb2_queue缓存队列上 */struct vb2_queue *q = vb->vb2_queue;vb->state = VB2_BUF_STATE_ACTIVE;/* 调用缓存队列上的ops操作方法集中的buf_queue */q->ops->buf_queue(vb);回调static const struct vb2_ops vivi_video_qops = {.buf_queue= buffer_queue,static void buffer_queue(struct vb2_buffer *vb)list_add_tail(&buf->list, &vidq->active);//回到__enqueue_in_driver(vb);下面ret = vb2_start_streaming(q);ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));/* 宏解析，就是调用 vb2_queue中的ops中的start_streaming函数*/#define call_qop(q, op, args...)\(((q)->ops->op) ? ((q)->ops->op(args)) : 0)//回调vb2_queue中的ops中的start_streaming函数static const struct vb2_ops vivi_video_qops = {.start_streaming= start_streaming,static int start_streaming(struct vb2_queue *vq, unsigned int count)vivi_start_generating(dev);/* 创建内核线程 */dma_q->kthread = kthread_run(vivi_thread, dev, "%s",dev->v4l2_dev.name);跳到内核线程 static int vivi_thread(void *data)vivi_sleep(dev);//计算超时时间timeout = msecs_to_jiffies(frames_to_ms(dev, 1));vivi_thread_tick(dev);/* 从vivi_dev中的vivi_dmaqueue中取出一个激活的vivi_buffer */buf = list_entry(dma_q->active.next, struct vivi_buffer, list);/* 然后从vivi_dmaqueue队列中删除刚才的那个vivi_buffer */list_del(&buf->list);/* Fill buffer */vivi_fillbuff(dev, buf);vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);/* 将vb2_buffer加入到vb2_queue的完成链表中 */list_add_tail(&vb->done_entry, &q->done_list);/* 唤醒因为读完成队列中的数据为空时而休眠的阻塞 */wake_up(&q->done_wq);static const struct v4l2_ioctl_ops vivi_ioctl_ops = {.vidioc_querycap = vidioc_querycap,.vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,.vidioc_g_fmt_vid_cap = vidioc_g_fmt_vid_cap,.vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,.vidioc_s_fmt_vid_cap = vidioc_s_fmt_vid_cap,.vidioc_enum_framesizes = vidioc_enum_framesizes,.vidioc_reqbufs = vb2_ioctl_reqbufs,.vidioc_create_bufs = vb2_ioctl_create_bufs,.vidioc_prepare_buf = vb2_ioctl_prepare_buf,.vidioc_querybuf = vb2_ioctl_querybuf,.vidioc_qbuf = vb2_ioctl_qbuf,.vidioc_dqbuf = vb2_ioctl_dqbuf,.vidioc_enum_input = vidioc_enum_input,.vidioc_g_input = vidioc_g_input,.vidioc_s_input = vidioc_s_input,.vidioc_enum_frameintervals = vidioc_enum_frameintervals,.vidioc_g_parm = vidioc_g_parm,.vidioc_s_parm = vidioc_s_parm,.vidioc_streamon = vb2_ioctl_streamon,.vidioc_streamoff = vb2_ioctl_streamoff,.vidioc_log_status = v4l2_ctrl_log_status,.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,.vidioc_unsubscribe_event = v4l2_event_unsubscribe,};struct v4l2_ioctl_info {unsigned int ioctl;u32 flags;const char * const name;union {u32 offset;int (*func)(const struct v4l2_ioctl_ops *ops,struct file *file, void *fh, void *p);} u;void (*debug)(const void *arg, bool write_only);};static struct v4l2_ioctl_info v4l2_ioctls[] = {IOCTL_INFO_FNC(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),IOCTL_INFO_FNC(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),IOCTL_INFO_FNC(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, INFO_FL_CLEAR(v4l2_format, type)),IOCTL_INFO_FNC(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),IOCTL_INFO_FNC(VIDIOC_QUERYBUF, v4l_querybuf, v4l_print_buffer, INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_buffer, length)),IOCTL_INFO_STD(VIDIOC_G_FBUF, vidioc_g_fbuf, v4l_print_framebuffer, 0),IOCTL_INFO_STD(VIDIOC_S_FBUF, vidioc_s_fbuf, v4l_print_framebuffer, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_OVERLAY, v4l_overlay, v4l_print_u32, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_QBUF, v4l_qbuf, v4l_print_buffer, INFO_FL_QUEUE),IOCTL_INFO_STD(VIDIOC_EXPBUF, vidioc_expbuf, v4l_print_exportbuffer, INFO_FL_QUEUE | INFO_FL_CLEAR(v4l2_exportbuffer, flags)),IOCTL_INFO_FNC(VIDIOC_DQBUF, v4l_dqbuf, v4l_print_buffer, INFO_FL_QUEUE),IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE),IOCTL_INFO_FNC(VIDIOC_STREAMOFF, v4l_streamoff, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE),IOCTL_INFO_FNC(VIDIOC_G_PARM, v4l_g_parm, v4l_print_streamparm, INFO_FL_CLEAR(v4l2_streamparm, type)),IOCTL_INFO_FNC(VIDIOC_S_PARM, v4l_s_parm, v4l_print_streamparm, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_STD, vidioc_g_std, v4l_print_std, 0),IOCTL_INFO_FNC(VIDIOC_S_STD, v4l_s_std, v4l_print_std, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_ENUMSTD, v4l_enumstd, v4l_print_standard, INFO_FL_CLEAR(v4l2_standard, index)),IOCTL_INFO_FNC(VIDIOC_ENUMINPUT, v4l_enuminput, v4l_print_enuminput, INFO_FL_CLEAR(v4l2_input, index)),IOCTL_INFO_FNC(VIDIOC_G_CTRL, v4l_g_ctrl, v4l_print_control, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_control, id)),IOCTL_INFO_FNC(VIDIOC_S_CTRL, v4l_s_ctrl, v4l_print_control, INFO_FL_PRIO | INFO_FL_CTRL),IOCTL_INFO_FNC(VIDIOC_G_TUNER, v4l_g_tuner, v4l_print_tuner, INFO_FL_CLEAR(v4l2_tuner, index)),IOCTL_INFO_FNC(VIDIOC_S_TUNER, v4l_s_tuner, v4l_print_tuner, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_AUDIO, vidioc_g_audio, v4l_print_audio, 0),IOCTL_INFO_STD(VIDIOC_S_AUDIO, vidioc_s_audio, v4l_print_audio, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)),IOCTL_INFO_FNC(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)),IOCTL_INFO_STD(VIDIOC_G_INPUT, vidioc_g_input, v4l_print_u32, 0),IOCTL_INFO_FNC(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_OUTPUT, vidioc_g_output, v4l_print_u32, 0),IOCTL_INFO_FNC(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)),IOCTL_INFO_STD(VIDIOC_G_AUDOUT, vidioc_g_audout, v4l_print_audioout, 0),IOCTL_INFO_STD(VIDIOC_S_AUDOUT, vidioc_s_audout, v4l_print_audioout, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_G_MODULATOR, v4l_g_modulator, v4l_print_modulator, INFO_FL_CLEAR(v4l2_modulator, index)),IOCTL_INFO_STD(VIDIOC_S_MODULATOR, vidioc_s_modulator, v4l_print_modulator, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_G_FREQUENCY, v4l_g_frequency, v4l_print_frequency, INFO_FL_CLEAR(v4l2_frequency, tuner)),IOCTL_INFO_FNC(VIDIOC_S_FREQUENCY, v4l_s_frequency, v4l_print_frequency, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_CROPCAP, v4l_cropcap, v4l_print_cropcap, INFO_FL_CLEAR(v4l2_cropcap, type)),IOCTL_INFO_FNC(VIDIOC_G_CROP, v4l_g_crop, v4l_print_crop, INFO_FL_CLEAR(v4l2_crop, type)),IOCTL_INFO_FNC(VIDIOC_S_CROP, v4l_s_crop, v4l_print_crop, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_SELECTION, vidioc_g_selection, v4l_print_selection, 0),IOCTL_INFO_STD(VIDIOC_S_SELECTION, vidioc_s_selection, v4l_print_selection, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_JPEGCOMP, vidioc_g_jpegcomp, v4l_print_jpegcompression, 0),IOCTL_INFO_STD(VIDIOC_S_JPEGCOMP, vidioc_s_jpegcomp, v4l_print_jpegcompression, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_QUERYSTD, v4l_querystd, v4l_print_std, 0),IOCTL_INFO_FNC(VIDIOC_TRY_FMT, v4l_try_fmt, v4l_print_format, 0),IOCTL_INFO_STD(VIDIOC_ENUMAUDIO, vidioc_enumaudio, v4l_print_audio, INFO_FL_CLEAR(v4l2_audio, index)),IOCTL_INFO_STD(VIDIOC_ENUMAUDOUT, vidioc_enumaudout, v4l_print_audioout, INFO_FL_CLEAR(v4l2_audioout, index)),IOCTL_INFO_FNC(VIDIOC_G_PRIORITY, v4l_g_priority, v4l_print_u32, 0),IOCTL_INFO_FNC(VIDIOC_S_PRIORITY, v4l_s_priority, v4l_print_u32, INFO_FL_PRIO),IOCTL_INFO_FNC(VIDIOC_G_SLICED_VBI_CAP, v4l_g_sliced_vbi_cap, v4l_print_sliced_vbi_cap, INFO_FL_CLEAR(v4l2_sliced_vbi_cap, type)),IOCTL_INFO_FNC(VIDIOC_LOG_STATUS, v4l_log_status, v4l_print_newline, 0),IOCTL_INFO_FNC(VIDIOC_G_EXT_CTRLS, v4l_g_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),IOCTL_INFO_FNC(VIDIOC_S_EXT_CTRLS, v4l_s_ext_ctrls, v4l_print_ext_controls, INFO_FL_PRIO | INFO_FL_CTRL),IOCTL_INFO_FNC(VIDIOC_TRY_EXT_CTRLS, v4l_try_ext_ctrls, v4l_print_ext_controls, INFO_FL_CTRL),IOCTL_INFO_STD(VIDIOC_ENUM_FRAMESIZES, vidioc_enum_framesizes, v4l_print_frmsizeenum, INFO_FL_CLEAR(v4l2_frmsizeenum, pixel_format)),IOCTL_INFO_STD(VIDIOC_ENUM_FRAMEINTERVALS, vidioc_enum_frameintervals, v4l_print_frmivalenum, INFO_FL_CLEAR(v4l2_frmivalenum, height)),IOCTL_INFO_STD(VIDIOC_G_ENC_INDEX, vidioc_g_enc_index, v4l_print_enc_idx, 0),IOCTL_INFO_STD(VIDIOC_ENCODER_CMD, vidioc_encoder_cmd, v4l_print_encoder_cmd, INFO_FL_PRIO | INFO_FL_CLEAR(v4l2_encoder_cmd, flags)),IOCTL_INFO_STD(VIDIOC_TRY_ENCODER_CMD, vidioc_try_encoder_cmd, v4l_print_encoder_cmd, INFO_FL_CLEAR(v4l2_encoder_cmd, flags)),IOCTL_INFO_STD(VIDIOC_DECODER_CMD, vidioc_decoder_cmd, v4l_print_decoder_cmd, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_TRY_DECODER_CMD, vidioc_try_decoder_cmd, v4l_print_decoder_cmd, 0),IOCTL_INFO_FNC(VIDIOC_DBG_S_REGISTER, v4l_dbg_s_register, v4l_print_dbg_register, 0),IOCTL_INFO_FNC(VIDIOC_DBG_G_REGISTER, v4l_dbg_g_register, v4l_print_dbg_register, 0),IOCTL_INFO_FNC(VIDIOC_S_HW_FREQ_SEEK, v4l_s_hw_freq_seek, v4l_print_hw_freq_seek, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_S_DV_TIMINGS, vidioc_s_dv_timings, v4l_print_dv_timings, INFO_FL_PRIO),IOCTL_INFO_STD(VIDIOC_G_DV_TIMINGS, vidioc_g_dv_timings, v4l_print_dv_timings, 0),IOCTL_INFO_FNC(VIDIOC_DQEVENT, v4l_dqevent, v4l_print_event, 0),IOCTL_INFO_FNC(VIDIOC_SUBSCRIBE_EVENT, v4l_subscribe_event, v4l_print_event_subscription, 0),IOCTL_INFO_FNC(VIDIOC_UNSUBSCRIBE_EVENT, v4l_unsubscribe_event, v4l_print_event_subscription, 0),IOCTL_INFO_FNC(VIDIOC_CREATE_BUFS, v4l_create_bufs, v4l_print_create_buffers, INFO_FL_PRIO | INFO_FL_QUEUE),IOCTL_INFO_FNC(VIDIOC_PREPARE_BUF, v4l_prepare_buf, v4l_print_buffer, INFO_FL_QUEUE),IOCTL_INFO_STD(VIDIOC_ENUM_DV_TIMINGS, vidioc_enum_dv_timings, v4l_print_enum_dv_timings, 0),IOCTL_INFO_STD(VIDIOC_QUERY_DV_TIMINGS, vidioc_query_dv_timings, v4l_print_dv_timings, 0),IOCTL_INFO_STD(VIDIOC_DV_TIMINGS_CAP, vidioc_dv_timings_cap, v4l_print_dv_timings_cap, INFO_FL_CLEAR(v4l2_dv_timings_cap, type)),IOCTL_INFO_FNC(VIDIOC_ENUM_FREQ_BANDS, v4l_enum_freq_bands, v4l_print_freq_band, 0),IOCTL_INFO_FNC(VIDIOC_DBG_G_CHIP_INFO, v4l_dbg_g_chip_info, v4l_print_dbg_chip_info, INFO_FL_CLEAR(v4l2_dbg_chip_info, match)),};static const struct video_device vivi_template = {.name= "vivi",.fops = &vivi_fops,.ioctl_ops = &vivi_ioctl_ops,.release= video_device_release_empty,};static const struct file_operations v4l2_fops = {.owner = THIS_MODULE,.read = v4l2_read,.write = v4l2_write,.open = v4l2_open,.get_unmapped_area = v4l2_get_unmapped_area,.mmap = v4l2_mmap,.unlocked_ioctl = v4l2_ioctl,#ifdef CONFIG_COMPAT.compat_ioctl = v4l2_compat_ioctl32,#endif.release = v4l2_release,.poll = v4l2_poll,.llseek = no_llseek,};/* 视频缓存buf是由缓存队列来管理的 */struct vb2_queue {enum v4l2_buf_typetype;unsigned intio_modes;unsigned intio_flags;struct mutex*lock;struct v4l2_fh*owner;/* 操作buf的方法集 */const struct vb2_ops*ops;/* 分配缓存的操作方法集 */const struct vb2_mem_ops*mem_ops;void*drv_priv;unsigned intbuf_struct_size;u32timestamp_type;gfp_tgfp_flags;/* private: internal use only */enum v4l2_memorymemory;struct vb2_buffer*bufs[VIDEO_MAX_FRAME];unsigned intnum_buffers;struct list_headqueued_list;atomic_tqueued_count;struct list_headdone_list;spinlock_tdone_lock;wait_queue_head_tdone_wq;void*alloc_ctx[VIDEO_MAX_PLANES];unsigned intplane_sizes[VIDEO_MAX_PLANES];unsigned intstreaming:1;unsigned intretry_start_streaming:1;unsigned intwaiting_for_buffers:1;struct vb2_fileio_data*fileio;};