Book Pro 3, MacBook Pro 4 and MacBook
Pro 5.

Its known to work with limitations on MacBook 5 / MacBook Air 2. Changing
brightness within X doesn't work, if using Nvidia's proprietary graphics
driver with no known fix at present. Changing brightness on a text console
or using the open-source driver does work.

MacBook Pro 5 has a known bug where the initial brightness after bootup is
the last recently used brightness (in Mac OSX), while the firmware reports
maximum. Impossible to fix.

[akpm@linux-foundation.org: build fix]
[rpurdie@linux.intel.com: Rebased the patch against latest git]
Signed-off-by: Mario Schwalbe <schwalbe@inf.tu-dresden.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Äf