ioctl MEDIA_IOC_ENUM_ENTITIES &manvol; MEDIA_IOC_ENUM_ENTITIES Enumerate entities and their properties int ioctl int fd int request struct media_entity_desc *argp fd File descriptor returned by open(). request MEDIA_IOC_ENUM_ENTITIES argp To query the attributes of an entity, applications set the id field of a &media-entity-desc; structure and call the MEDIA_IOC_ENUM_ENTITIES ioctl with a pointer to this structure. The driver fills the rest of the structure or returns an &EINVAL; when the id is invalid. Entities can be enumerated by or'ing the id with the MEDIA_ENT_ID_FLAG_NEXT flag. The driver will return information about the entity with the smallest id strictly larger than the requested one ('next entity'), or the &EINVAL; if there is none. Entity IDs can be non-contiguous. Applications must not try to enumerate entities by calling MEDIA_IOC_ENUM_ENTITIES with increasing id's until they get an error. Two or more entities that share a common non-zero group_id value are considered as logically grouped. Groups are used to report ALSA, VBI and video nodes that carry the same media stream lens and flash controllers associated with a sensor __u32 id Entity id, set by the application. When the id is or'ed with MEDIA_ENT_ID_FLAG_NEXT, the driver clears the flag and returns the first entity with a larger id. char name[32] Entity name as an UTF-8 NULL-terminated string. __u32 type Entity type, see for details. __u32 revision Entity revision in a driver/hardware specific format. __u32 flags Entity flags, see for details. __u32 group_id Entity group ID __u16 pads Number of pads __u16 links Total number of outbound links. Inbound links are not counted in this field. union struct v4l Valid for V4L sub-devices and nodes only. __u32 major V4L device node major number. For V4L sub-devices with no device node, set by the driver to 0. __u32 minor V4L device node minor number. For V4L sub-devices with no device node, set by the driver to 0. struct fb Valid for frame buffer nodes only. __u32 major Frame buffer device node major number. __u32 minor Frame buffer device node minor number. struct alsa Valid for ALSA devices only. __u32 card ALSA card number __u32 device ALSA device number __u32 subdevice ALSA sub-device number int dvb DVB card number __u8 raw[180] MEDIA_ENT_T_DEVNODE Unknown device node MEDIA_ENT_T_DEVNODE_V4L V4L video, radio or vbi device node MEDIA_ENT_T_DEVNODE_FB Frame buffer device node MEDIA_ENT_T_DEVNODE_ALSA ALSA card MEDIA_ENT_T_DEVNODE_DVB DVB card MEDIA_ENT_T_V4L2_SUBDEV Unknown V4L sub-device MEDIA_ENT_T_V4L2_SUBDEV_SENSOR Video sensor MEDIA_ENT_T_V4L2_SUBDEV_FLASH Flash controller MEDIA_ENT_T_V4L2_SUBDEV_LENS Lens controller MEDIA_ENT_FL_DEFAULT Default entity for its type. Used to discover the default audio, VBI and video devices, the default camera sensor, ... &return-value; EINVAL The &media-entity-desc; id references a non-existing entity.