{"id":75867,"date":"2026-02-13T11:25:48","date_gmt":"2026-02-13T03:25:48","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/75867.html"},"modified":"2026-02-13T11:25:48","modified_gmt":"2026-02-13T03:25:48","slug":"%e3%80%90v4l2%e3%80%911-video_device-%e5%87%bd%e6%95%b0%e5%92%8c%e6%95%b0%e6%8d%ae%e7%bb%93%e6%9e%84","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/75867.html","title":{"rendered":"\u3010V4L2\u30111.video_device \u51fd\u6570\u548c\u6570\u636e\u7ed3\u6784"},"content":{"rendered":"

\u76ee\u5f55<\/p>\n

1.1. \u679a\u4e3e vfl_devnode_type<\/p>\n

1.2. \u679a\u4e3e vfl_devnode_direction<\/p>\n

1.3. \u679a\u4e3e v4l2_video_device_flags<\/p>\n

1.4. \u7ed3\u6784\u4f53 v4l2_prio_state<\/p>\n

1.5. v4l2_prio_init<\/p>\n

1.6. v4l2_prio_change<\/p>\n

1.7. v4l2_prio_open<\/p>\n

1.8. v4l2_prio_close<\/p>\n

1.9. v4l2_prio_max<\/p>\n

1.10. v4l2_prio_check<\/p>\n

1.11. \u7ed3\u6784\u4f53 v4l2_file_operations<\/p>\n

1.12. \u7ed3\u6784\u4f53 video_device<\/p>\n

1.13. media_entity_to_video_device<\/p>\n

1.14. to_video_device<\/p>\n

1.15. __video_register_device<\/p>\n

1.16. video_register_device<\/p>\n

1.17. video_register_device_no_warn<\/p>\n

1.18. video_unregister_device<\/p>\n

1.19. \u00a0video_device_alloc<\/p>\n

1.20. video_device_release<\/p>\n

1.21. video_device_release_empty<\/p>\n

1.22. v4l2_disable_ioctl<\/p>\n

1.23. video_get_drvdata<\/p>\n

1.24. video_set_drvdata<\/p>\n

1.25. video_devdata<\/p>\n

1.26. video_drvdata<\/p>\n

1.27. video_device_node_name<\/p>\n

1.28. video_is_registered<\/p>\n

\n

1.1. \u679a\u4e3e vfl_devnode_type<\/span><\/span><\/h4>\n

\u679a\u4e3evfl_devnode_type <\/p>\n

V4L2\u8bbe\u5907\u8282\u70b9\u7684\u7c7b\u578b<\/p>\n

\u5e38\u91cf<\/span><\/span><\/p>\n

    \n
  • \n

    VFL_TYPE_VIDEO<\/p>\n

    \u7528\u4e8e\u89c6\u9891\u8f93\u5165\/\u8f93\u51fa\u8bbe\u5907<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_VBI<\/p>\n

    \u7528\u4e8e\u5782\u76f4\u6d88\u9690\u6570\u636e（\u5373\u9690\u85cf\u5f0f\u5b57\u5e55\u3001\u56fe\u6587\u7535\u89c6）<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_RADIO<\/p>\n

    \u7528\u4e8e\u65e0\u7ebf\u7535\u8c03\u8c10\u5668<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_SUBDEV<\/p>\n

    \u7528\u4e8eV4L2\u5b50\u8bbe\u5907<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_SDR<\/p>\n

    \u7528\u4e8e\u8f6f\u4ef6\u5b9a\u4e49\u65e0\u7ebf\u7535\u8c03\u8c10\u5668<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_TOUCH<\/p>\n

    \u7528\u4e8e\u89e6\u6478\u4f20\u611f\u5668<\/p>\n<\/li>\n

  • \n

    VFL_TYPE_MAX<\/p>\n

    VFL\u7c7b\u578b\u7684\u6570\u91cf，\u5fc5\u987b\u59cb\u7ec8\u4f4d\u4e8e\u679a\u4e3e\u7684\u6700\u540e<\/p>\n<\/li>\n<\/ul>\n

    1.2. \u679a\u4e3e vfl_devnode_direction<\/span><\/span><\/h4>\n

    \u679a\u4e3evfl_devnode_direction <\/p>\n

    \u786e\u5b9astruct video_device\u662f\u5bf9\u5e94\u63a5\u6536\u5668\u3001\u53d1\u5c04\u5668\u8fd8\u662f\u5185\u5b58\u5230\u5185\u5b58\u8bbe\u5907\u3002<\/p>\n

    \u5e38\u91cf<\/span><\/span><\/p>\n

      \n
    • \n

      VFL_DIR_RX<\/p>\n

      \u8bbe\u5907\u662f\u63a5\u6536\u5668\u3002<\/p>\n<\/li>\n

    • \n

      VFL_DIR_TX<\/p>\n

      \u8bbe\u5907\u662f\u53d1\u5c04\u5668\u3002<\/p>\n<\/li>\n

    • \n

      VFL_DIR_M2M<\/p>\n

      \u8be5\u8bbe\u5907\u662f\u4e00\u79cd\u5185\u5b58\u5230\u5185\u5b58\u7684\u8bbe\u5907\u3002<\/p>\n<\/li>\n<\/ul>\n

      \u6ce8:\u00a0<\/span><\/span>\u5982\u679cenum vfl_devnode_type\u4e3aVFL_TYPE_SUBDEV，\u5219\u5ffd\u7565\u3002<\/span><\/span><\/p>\n

      1.3. \u679a\u4e3e v4l2_video_device_flags<\/span><\/span><\/h4>\n

      \u679a\u4e3ev4l2_video_device_flags <\/p>\n

      struct video_device \u6240\u4f7f\u7528\u7684\u6807\u5fd7<\/p>\n

      \u5e38\u91cf<\/span><\/span><\/p>\n

        \n
      • \n

        V4L2_FL_REGISTERED<\/p>\n

        \u8868\u793a\u5df2\u6ce8\u518c\u4e00\u4e2astruct video_device\u3002\u9a71\u52a8\u7a0b\u5e8f\u5982\u679c\u60f3\u963b\u6b62\u6240\u6709\u672a\u6765\u7684\u8bbe\u5907\u8bbf\u95ee，\u53ef\u4ee5\u6e05\u9664\u6b64\u6807\u5fd7\u3002\u8be5\u6807\u5fd7\u4f1a\u88abvideo_unregister_device\u6e05\u9664\u3002<\/p>\n<\/li>\n

      • \n

        V4L2_FL_USES_V4L2_FH<\/p>\n

        \u8868\u793a file->private_data \u6307\u5411 struct v4l2_fh\u3002\u8c03\u7528 v4l2_fh_init() \u65f6，\u5185\u6838\u4f1a\u8bbe\u7f6e\u6b64\u6807\u5fd7\u3002\u6240\u6709\u65b0\u9a71\u52a8\u7a0b\u5e8f\u90fd\u5e94\u4f7f\u7528\u5b83\u3002<\/p>\n<\/li>\n

      • \n

        V4L2_FL_QUIRK_INVERTED_CROP<\/p>\n

        \u4e00\u4e9b\u65e7\u7684M2M\u9a71\u52a8\u7a0b\u5e8f\u9519\u8bef\u5730\u4f7f\u7528\u4e86g\/s_crop\/cropcap：\u88c1\u526a\u548c\u5408\u6210\u88ab\u4ea4\u6362\u4e86\u3002\u5982\u679c\u8bbe\u7f6e\u4e86\u6b64\u6807\u5fd7，\u5219v4l2-ioctl.c\u4e2d\u7684g\/s_crop\/cropcap\u51fd\u6570\u4f1a\u4ea4\u6362\u9009\u62e9\u76ee\u6807\u3002\u8fd9\u4f7f\u5f97\u8fd9\u4e9b\u9a71\u52a8\u7a0b\u5e8f\u80fd\u591f\u6b63\u786e\u5b9e\u73b0\u9009\u62e9API，\u800c\u65e7\u7684\u88c1\u526aAPI\u4ecd\u4f1a\u6309\u9884\u671f\u5de5\u4f5c，\u4ee5\u4fdd\u6301\u5411\u540e\u517c\u5bb9\u6027\u3002\u5207\u52ff\u4e3a\u65b0\u9a71\u52a8\u7a0b\u5e8f\u8bbe\u7f6e\u6b64\u6807\u5fd7\u3002<\/p>\n<\/li>\n

      • \n

        V4L2_FL_SUBDEV_RO_DEVNODE<\/p>\n

        \u8868\u793a\u89c6\u9891\u8bbe\u5907\u8282\u70b9\u662f\u4ee5\u53ea\u8bfb\u6a21\u5f0f\u6ce8\u518c\u7684\u3002\u8be5\u6807\u5fd7\u4ec5\u9002\u7528\u4e8e\u4e3a\u5b50\u8bbe\u5907\u6ce8\u518c\u7684\u8bbe\u5907\u8282\u70b9，\u5f53\u4f7f\u7528v4l2_device_register_ro_subdev_nodes()\u6ce8\u518c\u5b50\u8bbe\u5907\u7684\u8bbe\u5907\u8282\u70b9\u65f6，\u7531\u5185\u6838\u8fdb\u884c\u8bbe\u7f6e，\u5e76\u88ab\u5b50\u8bbe\u5907ioctl\u5904\u7406\u7a0b\u5e8f\u7528\u4e8e\u9650\u5236\u5bf9\u67d0\u4e9bioctl\u8c03\u7528\u7684\u8bbf\u95ee\u3002<\/p>\n<\/li>\n<\/ul>\n

        1.4. \u7ed3\u6784\u4f53 v4l2_prio_state<\/span><\/span><\/h4>\n

        struct v4l2_prio_state \u7ed3\u6784\u4f53 <\/p>\n

        \u5b58\u50a8\u4f18\u5148\u7ea7\u72b6\u6001<\/p>\n

        \u5b9a\u4e49<\/span><\/span><\/p>\n

        struct v4l2_prio_state {
        \n atomic_t prios[4];
        \n}; <\/p>\n

        \u6210\u5458<\/span><\/span><\/p>\n

          \n
        • \n

          prios<\/p>\n

          \u7528\u4e8e\u5b58\u50a8\u6570\u7ec4\u4f18\u5148\u7ea7\u7684\u5143\u7d20\u6570\u7ec4<\/p>\n<\/li>\n<\/ul>\n

          \u63cf\u8ff0<\/span><\/span><\/p>\n

          \u6ce8:\u00a0<\/span><\/span>prios\u6570\u7ec4\u7684\u5927\u5c0f\u4e0e\u679a\u4e3ev4l2_priority\u5b9a\u4e49\u7684\u4f18\u5148\u7ea7\u7c7b\u578b\u6570\u91cf\u76f8\u5339\u914d\u3002<\/span><\/span><\/p>\n

          1.5. v4l2_prio_init<\/span><\/span><\/h4>\n

          void v4l2_prio_init(struct v4l2_prio_state *global) <\/p>\n

          \u521d\u59cb\u5316\u4e00\u4e2a struct v4l2_prio_state<\/p>\n

          \u53c2\u6570<\/span><\/span><\/p>\n

            \n
          • \n

            struct v4l2_prio_state *global<\/p>\n

            \u6307\u5411 struct v4l2_prio_state \u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

            1.6. v4l2_prio_change<\/span><\/span><\/h4>\n

            int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, enum v4l2_priority new) <\/p>\n

            \u66f4\u6539v4l2\u6587\u4ef6\u53e5\u67c4\u4f18\u5148\u7ea7<\/p>\n

            \u53c2\u6570<\/span><\/span><\/p>\n

              \n
            • \n

              struct v4l2_prio_state *global<\/p>\n

              \u6307\u5411\u8bbe\u5907\u8282\u70b9\u7684struct v4l2_prio_state\u7684\u6307\u9488\u3002<\/p>\n<\/li>\n

            • \n

              enum v4l2_priority *local<\/p>\n

              \u6307\u5411\u6240\u9700\u4f18\u5148\u7ea7\u7684\u6307\u9488，\u7531\u679a\u4e3ev4l2_priority\u5b9a\u4e49<\/p>\n<\/li>\n

            • \n

              enum v4l2_priority new<\/p>\n

              \u8bf7\u6c42\u7684\u4f18\u5148\u7ea7\u7c7b\u578b，\u7531\u679a\u4e3ev4l2_priority\u5b9a\u4e49\u3002<\/p>\n<\/li>\n<\/ul>\n

              \u63cf\u8ff0<\/span><\/span><\/p>\n

              \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u5e94\u7531V4L2\u6838\u5fc3\u4f7f\u7528\u3002<\/span><\/span><\/p>\n

              1.7. v4l2_prio_open<\/span><\/span><\/h4>\n

              void v4l2_prio_open(struct v4l2_prio_state *global，enum v4l2_priority *local) <\/p>\n

              \u5b9e\u73b0\u6587\u4ef6\u5904\u7406\u5668\u6253\u5f00\u7684\u4f18\u5148\u7ea7\u903b\u8f91<\/p>\n

              \u53c2\u6570<\/span><\/span><\/p>\n

                \n
              • \n

                struct v4l2_prio_state *global<\/p>\n

                \u6307\u5411\u8bbe\u5907\u8282\u70b9\u7684struct v4l2_prio_state\u7684\u6307\u9488\u3002<\/p>\n<\/li>\n

              • \n

                enum v4l2_priority *local<\/p>\n

                \u6307\u5411\u6240\u9700\u4f18\u5148\u7ea7\u7684\u6307\u9488，\u7531\u679a\u4e3ev4l2_priority\u5b9a\u4e49<\/p>\n<\/li>\n<\/ul>\n

                \u63cf\u8ff0<\/span><\/span><\/p>\n

                \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u5e94\u7531V4L2\u6838\u5fc3\u4f7f\u7528\u3002<\/span><\/span><\/p>\n

                1.8. v4l2_prio_close<\/span><\/span><\/h4>\n

                void v4l2_prio_close（struct v4l2_prio_state *global，enum v4l2_priority local） <\/p>\n

                \u5b9e\u73b0\u6587\u4ef6\u5904\u7406\u5668\u5173\u95ed\u7684\u4f18\u5148\u7ea7\u903b\u8f91<\/p>\n

                \u53c2\u6570<\/span><\/span><\/p>\n

                  \n
                • \n

                  struct v4l2_prio_state *global<\/p>\n

                  \u6307\u5411\u8bbe\u5907\u8282\u70b9\u7684struct v4l2_prio_state\u7684\u6307\u9488\u3002<\/p>\n<\/li>\n

                • \n

                  enum v4l2_priority local<\/p>\n

                  \u7531\u679a\u4e3ev4l2_priority\u5b9a\u4e49\u7684\u5f85\u91ca\u653e\u4f18\u5148\u7ea7<\/p>\n<\/li>\n<\/ul>\n

                  \u63cf\u8ff0<\/span><\/span><\/p>\n

                  \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u5e94\u7531V4L2\u6838\u5fc3\u4f7f\u7528\u3002<\/span><\/span><\/p>\n

                  1.9. v4l2_prio_max<\/span><\/span><\/h4>\n

                  enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global) <\/p>\n

                  \u8fd4\u56de\u5b58\u50a8\u5728global\u6570\u7ec4\u4e2d\u7684\u6700\u5927\u4f18\u5148\u7ea7\u3002<\/p>\n

                  \u53c2\u6570<\/span><\/span><\/p>\n

                    \n
                  • \n

                    struct v4l2_prio_state *global<\/p>\n

                    \u6307\u5411\u8bbe\u5907\u8282\u70b9\u7684struct v4l2_prio_state\u7684\u6307\u9488\u3002<\/p>\n<\/li>\n<\/ul>\n

                    \u63cf\u8ff0<\/span><\/span><\/p>\n

                    \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u5e94\u7531V4L2\u6838\u5fc3\u4f7f\u7528\u3002<\/span><\/span><\/p>\n

                    1.10. v4l2_prio_check<\/span><\/span><\/h4>\n

                    int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local) <\/p>\n

                    \u5b9e\u73b0\u6587\u4ef6\u5904\u7406\u7a0b\u5e8f\u5173\u95ed\u7684\u4f18\u5148\u7ea7\u903b\u8f91<\/p>\n

                    \u53c2\u6570<\/span><\/span><\/p>\n

                      \n
                    • \n

                      struct v4l2_prio_state *global<\/p>\n

                      \u6307\u5411\u8bbe\u5907\u8282\u70b9\u7684struct v4l2_prio_state\u7684\u6307\u9488\u3002<\/p>\n<\/li>\n

                    • \n

                      enum v4l2_priority local<\/p>\n

                      \u6240\u9700\u4f18\u5148\u7ea7，\u7531\u679a\u4e3ev4l2_priority local\u5b9a\u4e49<\/p>\n<\/li>\n<\/ul>\n

                      \u63cf\u8ff0<\/span><\/span><\/p>\n

                      \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u5e94\u7531V4L2\u6838\u5fc3\u4f7f\u7528\u3002<\/span><\/span><\/p>\n

                      1.11. \u7ed3\u6784\u4f53 v4l2_file_operations<\/span><\/span><\/h4>\n

                      struct v4l2_file_operations <\/p>\n

                      V4L2\u8bbe\u5907\u4f7f\u7528\u7684\u6587\u4ef6\u7cfb\u7edf\u64cd\u4f5c<\/p>\n

                      \u5b9a\u4e49<\/span><\/span><\/p>\n

                      struct v4l2_file_operations {
                      \n struct module *owner;
                      \n ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
                      \n ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
                      \n __poll_t (*poll) (struct file *, struct poll_table_struct *);
                      \n long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
                      \n#ifdef CONFIG_COMPAT;
                      \n long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);
                      \n#endif;
                      \n unsigned long (*get_unmapped_area) (struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
                      \n int (*mmap) (struct file *, struct vm_area_struct *);
                      \n int (*open) (struct file *);
                      \n int (*release) (struct file *);
                      \n}; <\/p>\n

                      \u6210\u5458<\/span><\/span><\/p>\n

                        \n
                      • \n

                        owner<\/p>\n

                        \u6307\u5411\u7ed3\u6784\u4f53\u6a21\u5757\u7684\u6307\u9488<\/p>\n<\/li>\n

                      • \n

                        read<\/p>\n

                        \u5b9e\u73b0read()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        write<\/p>\n

                        \u5b9e\u73b0write()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        poll<\/p>\n

                        \u5b9e\u73b0poll()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        unlocked_ioctl<\/p>\n

                        \u5b9e\u73b0ioctl()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        compat_ioctl32<\/p>\n

                        \u5728\u5185\u6838\u4f7f\u752864\u4f4d\u6307\u4ee4\u800c\u7528\u6237\u7a7a\u95f4\u4f7f\u752832\u4f4d\u7684\u7279\u6b8a\u60c5\u51b5\u4e0b，\u5b9e\u73b0ioctl()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c\u3002<\/p>\n<\/li>\n

                      • \n

                        get_unmapped_area<\/p>\n

                        \u7531mmap()\u7cfb\u7edf\u8c03\u7528\u8c03\u7528，\u5728%!CONFIG_MMU\u65f6\u4f7f\u7528<\/p>\n<\/li>\n

                      • \n

                        mmap<\/p>\n

                        \u5b9e\u73b0mmap()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        open<\/p>\n

                        \u5b9e\u73b0open()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n

                      • \n

                        release<\/p>\n

                        \u5b9e\u73b0release()\u7cfb\u7edf\u8c03\u7528\u6240\u9700\u7684\u64cd\u4f5c<\/p>\n<\/li>\n<\/ul>\n

                        \u63cf\u8ff0<\/span><\/span><\/p>\n

                        \u6ce8：<\/span><\/span>\u8fd9\u4e9b\u64cd\u4f5c\u7528\u4e8e\u5728V4L2\u9a71\u52a8\u7a0b\u5e8f\u4e2d\u5b9e\u73b0fs\u7ed3\u6784\u4f53file_operations\u3002V4L2\u6838\u5fc3\u4f1a\u7528\u5b50\u7cfb\u7edf\u6240\u9700\u7684\u4e00\u4e9b\u989d\u5916\u903b\u8f91\u8986\u76d6\u6587\u4ef6\u7cfb\u7edf\u64cd\u4f5c\u3002<\/span><\/span><\/p>\n

                        \n

                        1.12. \u7ed3\u6784\u4f53 video_device<\/span><\/span><\/h4>\n

                        struct video_device <\/p>\n

                        \u7528\u4e8e\u521b\u5efa\u548c\u7ba1\u7406V4L2\u8bbe\u5907\u8282\u70b9\u7684\u7ed3\u6784\u3002<\/p>\n

                        \u5b9a\u4e49<\/span><\/span><\/p>\n

                        struct video_device {
                        \n#if defined(CONFIG_MEDIA_CONTROLLER);
                        \n struct media_entity entity;
                        \n struct media_intf_devnode *intf_devnode;
                        \n struct media_pipeline pipe;
                        \n#endif;
                        \n const struct v4l2_file_operations *fops;
                        \n u32 device_caps;
                        \n struct device dev;
                        \n struct cdev *cdev;
                        \n struct v4l2_device *v4l2_dev;
                        \n struct device *dev_parent;
                        \n struct v4l2_ctrl_handler *ctrl_handler;
                        \n struct vb2_queue *queue;
                        \n struct v4l2_prio_state *prio;
                        \n char name[32];
                        \n enum vfl_devnode_type vfl_type;
                        \n enum vfl_devnode_direction vfl_dir;
                        \n int minor;
                        \n u16 num;
                        \n unsigned long flags;
                        \n int index;
                        \n spinlock_t fh_lock;
                        \n struct list_head fh_list;
                        \n int dev_debug;
                        \n v4l2_std_id tvnorms;
                        \n void (*release)(struct video_device *vdev);
                        \n const struct v4l2_ioctl_ops *ioctl_ops;
                        \n unsigned long valid_ioctls[BITS_TO_LONGS(BASE_VIDIOC_PRIVATE)];
                        \n struct mutex *lock;
                        \n}; <\/p>\n

                        \u6210\u5458<\/span><\/span><\/p>\n

                          \n
                        • \n

                          entity<\/p>\n

                          struct media_entity <\/p>\n<\/li>\n

                        • \n

                          intf_devnode<\/p>\n

                          \u6307\u5411 struct media_intf_devnode \u7684\u6307\u9488<\/p>\n<\/li>\n

                        • \n

                          pipe<\/p>\n

                          struct media_pipeline <\/p>\n<\/li>\n

                        • \n

                          fops<\/p>\n

                          \u6307\u5411\u89c6\u9891\u8bbe\u5907\u7684struct v4l2_file_operations\u7684\u6307\u9488<\/p>\n<\/li>\n

                        • \n

                          device_caps<\/p>\n

                          v4l2_capabilities\u4e2d\u4f7f\u7528\u7684\u8bbe\u5907\u529f\u80fd<\/p>\n<\/li>\n

                        • \n

                          dev<\/p>\n

                          struct device（\u7528\u4e8e\u89c6\u9891\u8bbe\u5907）<\/p>\n<\/li>\n

                        • \n

                          cdev<\/p>\n

                          \u5b57\u7b26\u8bbe\u5907<\/p>\n<\/li>\n

                        • \n

                          v4l2_dev<\/p>\n

                          \u6307\u5411 struct v4l2_device \u7236\u8bbe\u5907\u7684\u6307\u9488<\/p>\n<\/li>\n

                        • \n

                          dev_parent<\/p>\n

                          \u6307\u5411struct device\u7684\u6307\u9488 parent<\/p>\n<\/li>\n

                        • \n

                          ctrl_handler<\/p>\n

                          \u4e0e\u6b64\u8bbe\u5907\u8282\u70b9\u76f8\u5173\u8054\u7684\u63a7\u5236\u5904\u7406\u5668\u3002\u53ef\u80fd\u4e3aNULL\u3002<\/p>\n<\/li>\n

                        • \n

                          queue<\/p>\n

                          \u4e0e\u8be5\u8bbe\u5907\u8282\u70b9\u76f8\u5173\u8054\u7684struct vb2_queue\u3002\u53ef\u80fd\u4e3aNULL\u3002<\/p>\n<\/li>\n

                        • \n

                          prio<\/p>\n

                          \u6307\u5411struct v4l2_prio_state\u7684\u6307\u9488，\u5305\u542b\u8bbe\u5907\u7684\u4f18\u5148\u7ea7\u72b6\u6001\u3002\u5982\u679c\u4e3aNULL，\u5219\u5c06\u4f7f\u7528v4l2_dev->prio\u3002<\/p>\n<\/li>\n

                        • \n

                          name<\/p>\n

                          \u89c6\u9891\u8bbe\u5907\u540d\u79f0<\/p>\n<\/li>\n

                        • \n

                          vfl_type<\/p>\n

                          V4L\u8bbe\u5907\u7c7b\u578b，\u7531enum vfl_devnode_type\u5b9a\u4e49<\/p>\n<\/li>\n

                        • \n

                          vfl_dir<\/p>\n

                          V4L\u63a5\u6536\u5668\u3001\u53d1\u5c04\u5668\u6216m2m<\/p>\n<\/li>\n

                        • \n

                          minor<\/p>\n

                          \u8bbe\u5907\u8282\u70b9\u201c\u6b21\u8bbe\u5907\u53f7\u201d\u3002\u5982\u679c\u6ce8\u518c\u5931\u8d25，\u5b83\u4f1a\u88ab\u8bbe\u4e3a-1\u3002<\/p>\n<\/li>\n

                        • \n

                          num<\/p>\n

                          \u89c6\u9891\u8bbe\u5907\u8282\u70b9\u7f16\u53f7<\/p>\n<\/li>\n

                        • \n

                          flags<\/p>\n

                          \u89c6\u9891\u8bbe\u5907\u6807\u5fd7\u3002\u4f7f\u7528\u4f4d\u64cd\u4f5c\u6765\u8bbe\u7f6e\/\u6e05\u9664\/\u6d4b\u8bd5\u6807\u5fd7\u3002\u5305\u542b\u4e00\u7ec4enum v4l2_video_device_flags\u3002<\/p>\n<\/li>\n

                        • \n

                          index<\/p>\n

                          \u7528\u4e8e\u533a\u5206\u540c\u4e00\u7269\u7406\u8bbe\u5907\u4e0a\u591a\u4e2a\u7d22\u5f15\u7684\u5c5e\u6027<\/p>\n<\/li>\n

                        • \n

                          fh_lock<\/p>\n

                          \u6240\u6709v4l2_fhs\u7684\u9501<\/p>\n<\/li>\n

                        • \n

                          fh_list<\/p>\n

                          struct v4l2_fh\u5217\u8868<\/p>\n<\/li>\n

                        • \n

                          dev_debug<\/p>\n

                          \u8bbe\u5907\u5185\u90e8\u8c03\u8bd5\u6807\u5fd7，\u4e0d\u4f9b\u9a71\u52a8\u7a0b\u5e8f\u4f7f\u7528<\/p>\n<\/li>\n

                        • \n

                          tvnorms<\/p>\n

                          \u652f\u6301\u7684\u7535\u89c6\u5236\u5f0f<\/p>\n<\/li>\n

                        • \n

                          release<\/p>\n

                          \u89c6\u9891\u8bbe\u5907release()\u56de\u8c03\u51fd\u6570<\/p>\n<\/li>\n

                        • \n

                          ioctl_ops<\/p>\n

                          \u6307\u5411\u5e26\u6709ioctl\u56de\u8c03\u7684struct v4l2_ioctl_ops\u7684\u6307\u9488<\/p>\n<\/li>\n

                        • \n

                          valid_ioctls<\/p>\n

                          \u6b64\u8bbe\u5907\u7684\u6709\u6548ioctl\u7684\u4f4d\u56fe<\/p>\n<\/li>\n

                        • \n

                          lock<\/p>\n

                          \u6307\u5411struct mutex\u5e8f\u5217\u5316\u9501\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                          \u63cf\u8ff0<\/span><\/span><\/p>\n

                          \u6ce8:\u00a0<\/span><\/span>\u53ea\u6709\u5728\u65e0\u6cd5\u4ecev4l2_dev\u4e2d\u63a8\u5bfc\u51fa\u6765\u65f6，\u624d\u8bbe\u7f6edev_parent\u3002<\/span><\/span><\/p>\n

                          1.13. <\/span><\/span>media_entity_to_video_device<\/h4>\n

                          media_entity_to_video_device (__entity) <\/p>\n

                          \u4ece\u5d4c\u5165\u7684struct media_entity\u8fd4\u56de\u4e00\u4e2astruct video_device\u3002<\/p>\n

                          \u53c2\u6570<\/span><\/span><\/p>\n

                            \n
                          • \n

                            __entity<\/p>\n

                            \u6307\u5411struct media_entity\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                            1.14. <\/span><\/span>to_video_device<\/h4>\n

                            to_video_device (cd) <\/p>\n

                            \u4ece\u5d4c\u5165\u7684struct device\u8fd4\u56de\u4e00\u4e2astruct video_device\u3002<\/p>\n

                            \u53c2\u6570<\/span><\/span><\/p>\n

                              \n
                            • \n

                              cd<\/p>\n

                              \u6307\u5411struct device\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                              1.15. __video_register_device<\/span><\/span><\/h4>\n

                              int __video_register_device(struct video_device *vdev, enum vfl_devnode_type type, int nr, int warn_if_nr_in_use, struct module *owner) <\/p>\n

                              \u6ce8\u518cvideo4linux\u8bbe\u5907<\/p>\n

                              \u53c2\u6570<\/span><\/span><\/p>\n

                                \n
                              • \n

                                struct video_device *vdev<\/p>\n

                                \u8981\u6ce8\u518c\u7684struct video_device<\/p>\n<\/li>\n

                              • \n

                                enum vfl_devnode_type type<\/p>\n

                                \u8981\u6ce8\u518c\u7684\u8bbe\u5907\u7c7b\u578b，\u7531enum vfl_devnode_type\u5b9a\u4e49<\/p>\n<\/li>\n

                              • \n

                                int nr<\/p>\n

                                \u671f\u671b\u7684\u8bbe\u5907\u8282\u70b9\u7f16\u53f7\u662f：（0 == \/dev\/video0，1 == \/dev\/video1，\u2026\u2026，-1 == \u7b2c\u4e00\u4e2a\u7a7a\u95f2\u8282\u70b9）<\/p>\n<\/li>\n

                              • \n

                                int warn_if_nr_in_use<\/p>\n

                                \u5982\u679c\u6240\u9700\u7684\u8bbe\u5907\u8282\u70b9\u53f7\u5df2\u88ab\u4f7f\u7528\u4e14\u9009\u62e9\u4e86\u53e6\u4e00\u4e2a\u7f16\u53f7，\u5219\u53d1\u51fa\u8b66\u544a\u3002<\/p>\n<\/li>\n

                              • \n

                                struct module *owner<\/p>\n

                                \u62e5\u6709\u89c6\u9891\u8bbe\u5907\u8282\u70b9\u7684\u6a21\u5757<\/p>\n<\/li>\n<\/ul>\n

                                \u63cf\u8ff0<\/span><\/span><\/p>\n

                                \u6ce8\u518c\u4ee3\u7801\u6839\u636e\u8bf7\u6c42\u7684\u7c7b\u578b\u5206\u914d\u6b21\u7f16\u53f7\u548c\u8bbe\u5907\u8282\u70b9\u7f16\u53f7，\u5e76\u5411\u5185\u6838\u6ce8\u518c\u65b0\u7684\u8bbe\u5907\u8282\u70b9\u3002<\/span><\/span><\/p>\n

                                \u6b64\u51fd\u6570\u5047\u8bbestruct video_device\u5728\u5206\u914d\u65f6\u5df2\u6e05\u96f6，\u4e14\u4e0d\u5305\u542b\u4efb\u4f55\u9648\u65e7\u6570\u636e\u3002<\/span><\/span><\/p>\n

                                \u5982\u679c\u627e\u4e0d\u5230\u53ef\u7528\u7684\u6b21\u8981\u7f16\u53f7\u6216\u8bbe\u5907\u8282\u70b9\u7f16\u53f7，\u6216\u8005\u8bbe\u5907\u8282\u70b9\u6ce8\u518c\u5931\u8d25，\u5c06\u8fd4\u56de\u9519\u8bef\u3002<\/span><\/span><\/p>\n

                                \u6210\u529f\u65f6\u8fd4\u56de0\u3002<\/span><\/span><\/p>\n

                                \u6ce8:\u00a0<\/span><\/span>\u6b64\u51fd\u6570\u4ec5\u7528\u4e8eV4L2\u6838\u5fc3\u5185\u90e8\u3002\u9a71\u52a8\u7a0b\u5e8f\u5e94\u4f7f\u7528video_register_device()\u6216video_register_device_no_warn()\u3002<\/span><\/span><\/p>\n

                                1.16. <\/span><\/span>video_register_device<\/h4>\n

                                int video_register_device(struct video_device *vdev, enum vfl_devnode_type type, int nr) <\/p>\n

                                \u6ce8\u518cvideo4linux\u8bbe\u5907<\/p>\n

                                \u53c2\u6570<\/span><\/span><\/p>\n

                                  \n
                                • \n

                                  struct video_device *vdev<\/p>\n

                                  \u8981\u6ce8\u518c\u7684struct video_device\u7ed3\u6784\u4f53<\/p>\n<\/li>\n

                                • \n

                                  enum vfl_devnode_type type<\/p>\n

                                  \u8981\u6ce8\u518c\u7684\u8bbe\u5907\u7c7b\u578b，\u7531enum vfl_devnode_type\u5b9a\u4e49<\/p>\n<\/li>\n

                                • \n

                                  int nr<\/p>\n

                                  \u6240\u9700\u7684\u8bbe\u5907\u8282\u70b9\u7f16\u53f7：（0 == \/dev\/video0，1 == \/dev\/video1，\u2026\u2026，-1 == \u7b2c\u4e00\u4e2a\u7a7a\u95f2）<\/p>\n<\/li>\n<\/ul>\n

                                  \u63cf\u8ff0<\/span><\/span><\/p>\n

                                  \u5728\u5185\u90e8，\u5b83\u4f1a\u8c03\u7528__video_register_device()\u3002\u6709\u5173\u66f4\u591a\u8be6\u7ec6\u4fe1\u606f，\u8bf7\u53c2\u9605\u5176\u6587\u6863\u3002<\/span><\/span><\/p>\n

                                  \u6ce8<\/span><\/span><\/p>\n

                                  \u5982\u679cvideo_register_device\u5931\u8d25，struct video_device\u7ed3\u6784\u4f53\u7684release()\u56de\u8c03\u51fd\u6570\u4e0d\u4f1a\u88ab\u8c03\u7528，\u56e0\u6b64\u8c03\u7528\u8005\u8d1f\u8d23\u91ca\u653e\u6240\u6709\u6570\u636e\u3002\u901a\u5e38\u8fd9\u610f\u5473\u7740\u5728\u5931\u8d25\u65f6\u5e94\u8be5\u8c03\u7528video_device_release()\u3002<\/span><\/span><\/p>\n

                                  1.17. video_register_device_no_warn<\/span><\/span><\/h4>\n

                                  int video_register_device_no_warn(struct video_device *vdev, enum vfl_devnode_type type, int nr) <\/p>\n

                                  \u6ce8\u518cvideo4linux\u8bbe\u5907<\/p>\n

                                  \u53c2\u6570<\/span><\/span><\/p>\n

                                    \n
                                  • \n

                                    struct video_device *vdev<\/p>\n

                                    \u8981\u6ce8\u518c\u7684struct video_device\u7ed3\u6784\u4f53<\/p>\n<\/li>\n

                                  • \n

                                    enum vfl_devnode_type type<\/p>\n

                                    \u8981\u6ce8\u518c\u7684\u8bbe\u5907\u7c7b\u578b，\u7531enum vfl_devnode_type\u5b9a\u4e49<\/p>\n<\/li>\n

                                  • \n

                                    int nr<\/p>\n

                                    \u6240\u9700\u7684\u8bbe\u5907\u8282\u70b9\u53f7：（0 == \/dev\/video0，1 == \/dev\/video1，\u2026\u2026，-1 == \u7b2c\u4e00\u4e2a\u7a7a\u95f2\u8282\u70b9）<\/p>\n<\/li>\n<\/ul>\n

                                    \u63cf\u8ff0<\/span><\/span><\/p>\n

                                    \u6b64\u51fd\u6570\u4e0evideo_register_device()\u76f8\u540c，\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e，\u5982\u679c\u6240\u9700\u7684\u8bbe\u5907\u8282\u70b9\u53f7\u5df2\u5728\u4f7f\u7528\u4e2d，\u4e0d\u4f1a\u53d1\u51fa\u8b66\u544a\u3002<\/span><\/span><\/p>\n

                                    \u5728\u5185\u90e8，\u5b83\u4f1a\u8c03\u7528__video_register_device()\u3002\u6709\u5173\u66f4\u591a\u8be6\u7ec6\u4fe1\u606f，\u8bf7\u53c2\u9605\u5176\u6587\u6863\u3002<\/span><\/span><\/p>\n

                                    \u6ce8<\/span><\/span>\u5982\u679cvideo_register_device\u5931\u8d25，struct video_device\u7ed3\u6784\u4f53\u7684release()\u56de\u8c03\u51fd\u6570\u4e0d\u4f1a\u88ab\u8c03\u7528，\u56e0\u6b64\u8c03\u7528\u8005\u8d1f\u8d23\u91ca\u653e\u6240\u6709\u6570\u636e\u3002\u901a\u5e38\u8fd9\u610f\u5473\u7740\u5728\u5931\u8d25\u65f6\u5e94\u8be5\u8c03\u7528video_device_release()\u3002<\/span><\/span><\/p>\n

                                    1.18. video_unregister_device<\/span><\/span><\/h4>\n

                                    void video_unregister_device(struct video_device *vdev) <\/p>\n

                                    \u6ce8\u9500\u89c6\u9891\u8bbe\u5907\u3002<\/p>\n

                                    \u53c2\u6570<\/span><\/span><\/p>\n

                                      \n
                                    • \n

                                      struct video_device *vdev<\/p>\n

                                      struct video_device \u7528\u4e8e\u6ce8\u518c<\/p>\n<\/li>\n<\/ul>\n

                                      \u63cf\u8ff0<\/span><\/span><\/p>\n

                                      \u5982\u679cvdev == NULL\u6216\u8005video_is_registered()\u8fd4\u56defalse，\u5219\u4e0d\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002<\/span><\/span><\/p>\n

                                      1.19. <\/span><\/span>\u00a0video_device_alloc<\/h4>\n

                                      struct video_device *video_device_alloc(void) <\/p>\n

                                      \u7528\u4e8e\u5206\u914dstruct video_device\u7684\u8f85\u52a9\u51fd\u6570<\/p>\n

                                      \u53c2\u6570<\/span><\/span><\/p>\n

                                        \n
                                      • \n

                                        void<\/p>\n

                                        \u65e0\u53c2\u6570<\/p>\n<\/li>\n<\/ul>\n

                                        \u63cf\u8ff0<\/span><\/span><\/p>\n

                                        \u5982\u679c\u4e3a-ENOMEM，\u5219\u8fd4\u56deNULL；\u6210\u529f\u65f6\u8fd4\u56destruct video_device\u3002<\/span><\/span><\/p>\n

                                        1.20. video_device_release<\/span><\/span><\/h4>\n

                                        void video_device_release(struct video_device *vdev) <\/p>\n

                                        \u91ca\u653estruct video_device\u7684\u8f85\u52a9\u51fd\u6570<\/p>\n

                                        \u53c2\u6570<\/span><\/span><\/p>\n

                                          \n
                                        • \n

                                          struct video_device *vdev<\/p>\n

                                          \u6307\u5411 struct video_device \u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                          \u63cf\u8ff0<\/span><\/span><\/p>\n

                                          \u4e5f\u53ef\u7528\u4e8evideo_device->release()\u3002<\/span><\/span><\/p>\n

                                          1.21. video_device_release_empty<\/span><\/span><\/h4>\n

                                          void video_device_release_empty(struct video_device *vdev) <\/p>\n

                                          \u7528\u4e8e\u5b9e\u73b0video_device->release()\u56de\u8c03\u7684\u8f85\u52a9\u51fd\u6570\u3002<\/p>\n

                                          \u53c2\u6570<\/span><\/span><\/p>\n

                                            \n
                                          • \n

                                            struct video_device *vdev<\/p>\n

                                            \u6307\u5411 struct video_device \u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                            \u63cf\u8ff0<\/span><\/span><\/p>\n

                                            \u6b64\u91ca\u653e\u51fd\u6570\u4e0d\u6267\u884c\u4efb\u4f55\u64cd\u4f5c\u3002<\/span><\/span><\/p>\n

                                            \u5f53video_device\u662f\u9759\u6001\u5168\u5c40\u7ed3\u6784\u4f53\u65f6，\u5e94\u4f7f\u7528\u6b64\u51fd\u6570\u3002<\/span><\/span><\/p>\n

                                            \u6ce8:\u00a0<\/span><\/span>\u62e5\u6709\u9759\u6001\u7684video_device\u5f80\u597d\u91cc\u8bf4\u4e5f\u662f\u4e00\u79cd\u53ef\u7591\u7684\u6784\u9020\u3002<\/span><\/span><\/p>\n

                                            1.22. v4l2_disable_ioctl<\/span><\/span><\/h4>\n

                                            void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) <\/p>\n

                                            \u6807\u8bb0\u7ed9\u5b9a\u547d\u4ee4\u672a\u5b9e\u73b0\u3002\u4e0d\u5e94\u4f7f\u7528\u6838\u5fc3\u9501\u5b9a<\/p>\n

                                            \u53c2\u6570<\/span><\/span><\/p>\n

                                              \n
                                            • \n

                                              struct video_device *vdev<\/p>\n

                                              \u6307\u5411 struct video_device \u7684\u6307\u9488<\/p>\n<\/li>\n

                                            • \n

                                              unsigned int cmd<\/p>\n

                                              ioctl\u547d\u4ee4<\/p>\n<\/li>\n<\/ul>\n

                                              \u63cf\u8ff0<\/span><\/span><\/p>\n

                                              \u6b64\u51fd\u6570\u5141\u8bb8\u9a71\u52a8\u7a0b\u5e8f\u4ec5\u63d0\u4f9b\u4e00\u4e2av4l2_ioctl_ops\u7ed3\u6784\u4f53，\u4f46\u4f1a\u6839\u636e\u5b9e\u9645\u68c0\u6d4b\u5230\u7684\u7279\u5b9a\u5361\u6765\u7981\u7528ioctl\u64cd\u4f5c\u3002<\/span><\/span><\/p>\n

                                              \u6ce8:\u00a0<\/span><\/span>\u8fd9\u5fc5\u987b\u5728 video_register_device \u4e4b\u524d\u8c03\u7528\u3002\u53e6\u8bf7\u53c2\u89c1 determine_valid_ioctls() \u7684\u6ce8\u91ca\u3002<\/span><\/span><\/p>\n

                                              1.23. video_get_drvdata<\/span><\/span><\/h4>\n

                                              void *video_get_drvdata(struct video_device *vdev) <\/p>\n

                                              \u4ecestruct video_device\u83b7\u53d6\u79c1\u6709\u6570\u636e\u3002<\/p>\n

                                              \u53c2\u6570<\/span><\/span><\/p>\n

                                                \n
                                              • \n

                                                struct video_device *vdev<\/p>\n

                                                \u6307\u5411struct video_device\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                \u63cf\u8ff0<\/span><\/span><\/p>\n

                                                \u8fd4\u56de\u6307\u5411\u79c1\u6709\u6570\u636e\u7684\u6307\u9488<\/span><\/span><\/p>\n

                                                1.24. video_set_drvdata<\/span><\/span><\/h4>\n

                                                void video_set_drvdata(struct video_device *vdev, void *data) <\/p>\n

                                                \u8bbe\u7f6e\u6765\u81eastruct video_device\u7684\u79c1\u6709\u6570\u636e\u3002<\/p>\n

                                                \u53c2\u6570<\/span><\/span><\/p>\n

                                                  \n
                                                • \n

                                                  struct video_device *vdev<\/p>\n

                                                  \u6307\u5411struct video_device\u7684\u6307\u9488<\/p>\n<\/li>\n

                                                • \n

                                                  void *data<\/p>\n

                                                  \u79c1\u6709\u6570\u636e\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                  1.25. <\/span><\/span>video_devdata<\/h4>\n

                                                  struct video_device *video_devdata(struct file *file) <\/p>\n

                                                  \u4ecestruct file\u83b7\u53d6struct video_device\u3002<\/p>\n

                                                  \u53c2\u6570<\/span><\/span><\/p>\n

                                                    \n
                                                  • \n

                                                    struct file *file<\/p>\n

                                                    \u6307\u5411struct file\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                    1.26. video_drvdata<\/span><\/span><\/h4>\n

                                                    void *video_drvdata(struct file *file) <\/p>\n

                                                    \u4f7f\u7528struct file\u4ecestruct video_device\u83b7\u53d6\u79c1\u6709\u6570\u636e\u3002<\/p>\n

                                                    \u53c2\u6570<\/span><\/span><\/p>\n

                                                      \n
                                                    • \n

                                                      struct file *file<\/p>\n

                                                      \u6307\u5411struct file\u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                      \u63cf\u8ff0<\/span><\/span><\/p>\n

                                                      \u8fd9\u4e2a\u51fd\u6570\u7ed3\u5408\u4e86video_get_drvdata()\u548cvideo_devdata()，\u56e0\u4e3a\u8fd9\u4e24\u4e2a\u51fd\u6570\u7684\u7ec4\u5408\u4f7f\u7528\u975e\u5e38\u9891\u7e41\u3002<\/span><\/span><\/p>\n

                                                      1.27. <\/span><\/span>video_device_node_name<\/h4>\n

                                                      const char *video_device_node_name(struct video_device *vdev) <\/p>\n

                                                      \u8fd4\u56de\u89c6\u9891\u8bbe\u5907\u540d\u79f0<\/p>\n

                                                      \u53c2\u6570<\/span><\/span><\/p>\n

                                                        \n
                                                      • \n

                                                        struct video_device *vdev<\/p>\n

                                                        \u6307\u5411 struct video_device \u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                        \u63cf\u8ff0<\/span><\/span><\/p>\n

                                                        \u8fd4\u56de\u8bbe\u5907\u540d\u79f0\u5b57\u7b26\u4e32<\/span><\/span><\/p>\n

                                                        1.28. <\/span><\/span>video_is_registered<\/h4>\n

                                                        int video_is_registered(struct video_device *vdev) <\/p>\n

                                                        \u5982\u679c struct video_device \u5df2\u6ce8\u518c，\u5219\u8fd4\u56de true\u3002<\/p>\n

                                                        \u53c2\u6570<\/span><\/span><\/p>\n

                                                          \n
                                                        • \n

                                                          struct video_device *vdev<\/p>\n

                                                          \u6307\u5411 struct video_device \u7684\u6307\u9488<\/p>\n<\/li>\n<\/ul>\n

                                                          \u63cf\u8ff0<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

                                                          \u76ee\u5f55
                                                          \n1.1. \u679a\u4e3e vfl_devnode_type
                                                          \n1.2. \u679a\u4e3e vfl_devnode_direction
                                                          \n1.3. \u679a\u4e3e v4l2_video_device_flags
                                                          \n1.4. \u7ed3\u6784\u4f53 v4l2_prio_state
                                                          \n1.5. v4l2_prio_init
                                                          \n1.6. v4l2_prio_change
                                                          \n1.7. v4l2_prio_open
                                                          \n1.8. v4l2_prio_close
                                                          \n1.9. v4l2_prio_max
                                                          \n1.10. v4l2_pr<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[8100,8101,58],"topic":[],"class_list":["post-75867","post","type-post","status-publish","format-standard","hentry","category-server","tag-v4l2","tag-8101","tag-linux"],"yoast_head":"\n\u3010V4L2\u30111.video_device \u51fd\u6570\u548c\u6570\u636e\u7ed3\u6784 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/75867.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u3010V4L2\u30111.video_device \u51fd\u6570\u548c\u6570\u636e\u7ed3\u6784 - 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