Binary package “radeontool” in ubuntu lucid
utility to control ATI Radeon backlight functions on laptops
Radeontool is a small utility to control ATI Radeon based laptops' backlight
and external output functions. It is also able to dump the contents of
registers for debugging purposes.
WARNING: Radeontool code has not been completely audited and may contain bugs
that could damage your hardware. Use at your own risk.