[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, 23 insertions, 0 deletions

diff --git a/include/linux/fb.h b/include/linux/fb.h
index 315d89740ddf..f1281687e549 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -1,6 +1,7 @@
 #ifndef _LINUX_FB_H
 #define _LINUX_FB_H
 
+#include <linux/backlight.h>
 #include <asm/types.h>
 
 /* Definitions of frame buffers                                         */
@@ -366,6 +367,12 @@ struct fb_cursor {
         struct fb_image image;  /* Cursor image */
 };
 
+#ifdef CONFIG_FB_BACKLIGHT
+/* Settings for the generic backlight code */
+#define FB_BACKLIGHT_LEVELS     128
+#define FB_BACKLIGHT_MAX        0xFF
+#endif
+
 #ifdef __KERNEL__
 
 #include <linux/fs.h>
@@ -756,6 +763,21 @@ struct fb_info {
         struct fb_cmap cmap;            /* Current cmap */
         struct list_head modelist;      /* mode list */
         struct fb_videomode *mode;      /* current mode */
+
+#ifdef CONFIG_FB_BACKLIGHT
+        /* Lock ordering:
+         * bl_mutex (protects bl_dev and bl_curve)
+         *   bl_dev->sem (backlight class)
+         */
+        struct mutex bl_mutex;
+
+        /* assigned backlight device */
+        struct backlight_device *bl_dev;
+
+        /* Backlight level curve */
+        u8 bl_curve[FB_BACKLIGHT_LEVELS];
+#endif
+
         struct fb_ops *fbops;
         struct device *device;
         struct class_device *class_device; /* sysfs per device attrs */
@@ -895,6 +917,7 @@ extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev);
 extern void framebuffer_release(struct fb_info *info);
 extern int fb_init_class_device(struct fb_info *fb_info);
 extern void fb_cleanup_class_device(struct fb_info *head);
+extern void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max);
 
 /* drivers/video/fbmon.c */
 #define FB_MAXTIMINGS           0