Question on registering driver fops

Hi, I noticed that after registering a video driver with "video_register_device" the "open" function gets called. The registration is like: peasycap->video_device.fops = &v4l2_fops; peasycap->video_device.minor = -1; peasycap->video_device.release = (void *)(&videodev_release); video_set_drvdata(&(peasycap->video_device), (void *)peasycap); First question: who calls it and why does it open the device? Second question. This is a common kernel interface, driver fills a "fops" struct and then registers. This means I need to be *always* prepared to get a call on "open" (or other file operation) immediately after driver registration? Thanks, Ezequiel.