[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>

1 files changed, 26 insertions, 4 deletions

diff --git a/drivers/video/chipsfb.c b/drivers/video/chipsfb.c
index 72ff6bf75e5e..d76bbfac92cc 100644
--- a/drivers/video/chipsfb.c
+++ b/drivers/video/chipsfb.c
@@ -148,9 +148,24 @@ static int chipsfb_set_par(struct fb_info *info)
 static int chipsfb_blank(int blank, struct fb_info *info)
 {
 #ifdef CONFIG_PMAC_BACKLIGHT
-        // used to disable backlight only for blank > 1, but it seems
-        // useful at blank = 1 too (saves battery, extends backlight life)
-        set_backlight_enable(!blank);
+        mutex_lock(&pmac_backlight_mutex);
+
+        if (pmac_backlight) {
+                down(&pmac_backlight->sem);
+
+                /* used to disable backlight only for blank > 1, but it seems
+                 * useful at blank = 1 too (saves battery, extends backlight
+                 * life)
+                 */
+                if (blank)
+                        pmac_backlight->props->power = FB_BLANK_POWERDOWN;
+                else
+                        pmac_backlight->props->power = FB_BLANK_UNBLANK;
+                pmac_backlight->props->update_status(pmac_backlight);
+                up(&pmac_backlight->sem);
+        }
+
+        mutex_unlock(&pmac_backlight_mutex);
 #endif /* CONFIG_PMAC_BACKLIGHT */
 
         return 1;       /* get fb_blank to set the colormap to all black */
@@ -401,7 +416,14 @@ chipsfb_pci_init(struct pci_dev *dp, const struct pci_device_id *ent)
 
 #ifdef CONFIG_PMAC_BACKLIGHT
         /* turn on the backlight */
-        set_backlight_enable(1);
+        mutex_lock(&pmac_backlight_mutex);
+        if (pmac_backlight) {
+                down(&pmac_backlight->sem);
+                pmac_backlight->props->power = FB_BLANK_UNBLANK;
+                pmac_backlight->props->update_status(pmac_backlight);
+                up(&pmac_backlight->sem);
+        }
+        mutex_unlock(&pmac_backlight_mutex);
 #endif /* CONFIG_PMAC_BACKLIGHT */
 
 #ifdef CONFIG_PPC