Kernel support for video and graphics overlay

[thomas.petazzoni@free-electrons.com (Thomas Petazzoni)]

Hello,

I am starting to work on a SuperH processor that has a graphics
controller capable of overlaying three layers :

 * one video layer, where the video comes from a camera interface
 * two graphics layer

A single hardware, controlled by a single set of registers, manages the
whole graphics controller. At the moment, the kernel only has a
framebuffer driver capable of outputting things on one graphic layer.

I'd like to be able to use the video layer, in order to inlay the video
coming from the camera into a graphical application.

My understanding is that the Video 4 Linux subsystem will play a role
in managing both the video input and the video output devices. However,
I can't seem to figure out how the work is divided between the video
input driver, the video output driver and the framebuffer driver.

Do you have pointers, or example of drivers for similar devices ?

Thanks,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com