[PATCH] Rewritten backlight infrastructure for portable Apple computers

This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers.  Backward compatibility is retained.  A sysfs
interface allows userland to control the brightness with more steps than
before.  Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.

[akpm@osdl.org: add needed exports]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/macintosh/Kconfig b/drivers/macintosh/Kconfig
index ccf5df4..37cd6ee 100644
--- a/drivers/macintosh/Kconfig
+++ b/drivers/macintosh/Kconfig
@@ -99,17 +99,22 @@
 	  devices are not fully supported in the bay as I never had one to
 	  try with
 
-# made a separate option since backlight may end up beeing used
-# on non-powerbook machines (but only on PMU based ones AFAIK)
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on ADB_PMU && (BROKEN || !PPC64)
 	help
-	  Say Y here to build in code to manage the LCD backlight on a
-	  Macintosh PowerBook.  With this code, the backlight will be turned
-	  on and off appropriately on power-management and lid-open/lid-closed
-	  events; also, the PowerBook button device will be enabled so you can
-	  change the screen brightness.
+	  Say Y here to enable Macintosh specific extensions of the generic
+	  backlight code. With this enabled, the brightness keys on older
+	  PowerBooks will be enabled so you can change the screen brightness.
+	  Newer models should use an userspace daemon like pbbuttonsd.
+
+config PMAC_BACKLIGHT_LEGACY
+	bool "Provide legacy ioctl's on /dev/pmu for the backlight"
+	depends on PMAC_BACKLIGHT && (BROKEN || !PPC64)
+	help
+	  Say Y if you want to enable legacy ioctl's on /dev/pmu. This is for
+	  programs which use this old interface. New and updated programs
+	  should use the backlight classes in sysfs.
 
 config ADB_MACIO
 	bool "Include MacIO (CHRP) ADB driver"