beaglebone camera

hi ,

I compiled the v4l2 for beaglebone.device node is created but its giving problem when i am trying to acccess the device node

ptmx tty2 tty56 vcsa6
pts tty20 tty57 video0
ram0 tty21 tty58 watchdog
ram1 tty22 tty59 zero
ram10 tty23 tty6
ram11 tty24 tty60
root@beaglebone:/dev# cat video0
cat: read error: Invalid argument
root@beaglebone:/dev#

video0 is giving as the invalid argument