[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>

3 files changed, 42 insertions, 15 deletions

diff --git a/include/asm-powerpc/backlight.h b/include/asm-powerpc/backlight.h
index 1ba1f27a0b6..a5e9e656e33 100644
--- a/include/asm-powerpc/backlight.h
+++ b/include/asm-powerpc/backlight.h
@@ -2,30 +2,30 @@
  * Routines for handling backlight control on PowerBooks
  *
  * For now, implementation resides in
- * arch/powerpc/platforms/powermac/pmac_support.c
+ * arch/powerpc/platforms/powermac/backlight.c
  *
  */
 #ifndef __ASM_POWERPC_BACKLIGHT_H
 #define __ASM_POWERPC_BACKLIGHT_H
 #ifdef __KERNEL__
 
-/* Abstract values */
-#define BACKLIGHT_OFF	0
-#define BACKLIGHT_MIN	1
-#define BACKLIGHT_MAX	0xf
+#include <linux/fb.h>
+#include <linux/mutex.h>
 
-struct backlight_controller {
-	int (*set_enable)(int enable, int level, void *data);
-	int (*set_level)(int level, void *data);
-};
+/* For locking instructions, see the implementation file */
+extern struct backlight_device *pmac_backlight;
+extern struct mutex pmac_backlight_mutex;
 
-extern void register_backlight_controller(struct backlight_controller *ctrler, void *data, char *type);
-extern void unregister_backlight_controller(struct backlight_controller *ctrler, void *data);
+extern void pmac_backlight_calc_curve(struct fb_info*);
+extern int pmac_backlight_curve_lookup(struct fb_info *info, int value);
 
-extern int set_backlight_enable(int enable);
-extern int get_backlight_enable(void);
-extern int set_backlight_level(int level);
-extern int get_backlight_level(void);
+extern int pmac_has_backlight_type(const char *type);
+
+extern void pmac_backlight_key_up(void);
+extern void pmac_backlight_key_down(void);
+
+extern int pmac_backlight_set_legacy_brightness(int brightness);
+extern int pmac_backlight_get_legacy_brightness(void);
 
 #endif /* __KERNEL__ */
 #endif
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 315d89740dd..f1281687e54 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
diff --git a/include/linux/pmu.h b/include/linux/pmu.h
index ecce5912f4d..2ed807ddc08 100644
--- a/include/linux/pmu.h
+++ b/include/linux/pmu.h
@@ -230,4 +230,8 @@ extern int pmu_battery_count;
 extern struct pmu_battery_info pmu_batteries[PMU_MAX_BATTERIES];
 extern unsigned int pmu_power_flags;
 
+/* Backlight */
+extern int disable_kernel_backlight;
+extern void pmu_backlight_init(struct device_node*);
+
 #endif	/* __KERNEL__ */