|Linux Kernel & Device Driver Programming|
Video for Linux Two (V4L2) is an API for access to video devices. For information on V4L2:
xawtv is an example of an X-windows application for viewing TV images. It was developed for a family of frame grabbers based on the BrookTree (now owned by Conextant) family of video decoder and digitizer chips, starting with the bt848 chip. It uses the v4l2 API, and so is worth reading to see how the v4L API is used. It is a candidate for a test application using your rame grabber driver. To use this, you will need to implement all the V4L functions that this application calls, including the ioctls it calls to find out what features the device supports. You can find out what those are by running xawtv with strace and a video device for which there is a working driver. I tried this. For the results see the link to a discussion of V4L ioctls below.
Links to info about other Linux video applications can be found at the video4linux wiki.