[PATCH] powermac: More powermac backlight fixes

This patch fixes several problems:
- The legacy backlight value might be set at interrupt time. Introduced
  a worker to prevent it from directly calling the backlight code.
- via-pmu allows the backlight to be grabbed, in which case we need to
  prevent other kernel code from changing the brightness.
- Don't send PMU requests in via-pmu-backlight when the machine is about
  to sleep or waking up.
- More Kconfig fixes.

Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-powerpc/backlight.h

@@ -30,8 +30,12 @@ static inline void pmac_backlight_key_down(void)
 	pmac_backlight_key(1);
 }
 
+extern void pmac_backlight_set_legacy_brightness_pmu(int brightness);
 extern int pmac_backlight_set_legacy_brightness(int brightness);
 extern int pmac_backlight_get_legacy_brightness(void);
 
+extern void pmac_backlight_enable(void);
+extern void pmac_backlight_disable(void);
+
 #endif /* __KERNEL__ */
 #endif