Missing Key-codes from <linux/input.h> file

Hi,
I'm working on a module which is an input device and hence it needs to
report certain key events.

While browsing through the <linux/input.h>, I did find most of the
key-codes(which I need to use) already defined but not all.

Few of the KEY_xxx which i could not find are:

a.) A Key for going to the previous channel.
b.) Keys for Moving upper-right, lower-right, upper-left and
lower-left direction(probably a GUI(or a grid of icons),where you move
diagonally)
d.) A key for Subpicture (this 'subpicture' key is defined in CEA-931C).

Any pointers?

Thanks,
Dharam