video_register_device -- register video4linux devices
(struct video_device * vfd, int type);
video device structure we want to register
type of device to register
needs a semaphore on 2.3.x
The registration code assigns minor numbers based on the type
requested. -ENFILE is returned in all the device slots for this
category are full. If not then the minor field is set and the
driver initialize function is called (if non NULL).
Zero is returned on success.
Valid types are
VFL_TYPE_GRABBER - A frame grabber
VFL_TYPE_VTX - A teletext device
VFL_TYPE_VBI - Vertical blank data (undecoded)
VFL_TYPE_RADIO - A radio card