[PATCH] backlight: lcd: Remove dependenct from the framebuffer layer

The backlight layer should be independent from the framebuffer layer.  It
can use the services offered by the framebuffer, but its absence should not
prevent the backlight/lcd layer from functioning.

[akpm@osdl.org: cleanups]
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 55 insertions, 32 deletions

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index f439a588394a..1dac9e743427 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -14,6 +14,59 @@
 #include <linux/err.h>
 #include <linux/fb.h>
 
+
+#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
+                           defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
+/* This callback gets called when something important happens inside a
+ * framebuffer driver. We're looking if that important event is blanking,
+ * and if it is, we're switching backlight power as well ...
+ */
+static int fb_notifier_callback(struct notifier_block *self,
+                                unsigned long event, void *data)
+{
+        struct backlight_device *bd;
+        struct fb_event *evdata = data;
+
+        /* If we aren't interested in this event, skip it immediately ... */
+        if (event != FB_EVENT_BLANK)
+                return 0;
+
+        bd = container_of(self, struct backlight_device, fb_notif);
+        down(&bd->sem);
+        if (bd->props)
+                if (!bd->props->check_fb ||
+                    bd->props->check_fb(evdata->info)) {
+                        bd->props->fb_blank = *(int *)evdata->data;
+                        if (likely(bd->props && bd->props->update_status))
+                                bd->props->update_status(bd);
+                }
+        up(&bd->sem);
+        return 0;
+}
+
+static int backlight_register_fb(struct backlight_device *bd)
+{
+        memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
+        bd->fb_notif.notifier_call = fb_notifier_callback;
+
+        return fb_register_client(&bd->fb_notif);
+}
+
+static void backlight_unregister_fb(struct backlight_device *bd)
+{
+        fb_unregister_client(&bd->fb_notif);
+}
+#else
+static inline int backlight_register_fb(struct backlight_device *bd)
+{
+        return 0;
+}
+
+static inline void backlight_unregister_fb(struct backlight_device *bd)
+{
+}
+#endif /* CONFIG_FB */
+
 static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
 {
         int rc = -ENXIO;
@@ -151,33 +204,6 @@ static const struct class_device_attribute bl_class_device_attributes[] = {
         DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
 };
 
-/* This callback gets called when something important happens inside a
- * framebuffer driver. We're looking if that important event is blanking,
- * and if it is, we're switching backlight power as well ...
- */
-static int fb_notifier_callback(struct notifier_block *self,
-                                unsigned long event, void *data)
-{
-        struct backlight_device *bd;
-        struct fb_event *evdata =(struct fb_event *)data;
-
-        /* If we aren't interested in this event, skip it immediately ... */
-        if (event != FB_EVENT_BLANK)
-                return 0;
-
-        bd = container_of(self, struct backlight_device, fb_notif);
-        down(&bd->sem);
-        if (bd->props)
-                if (!bd->props->check_fb ||
-                    bd->props->check_fb(evdata->info)) {
-                        bd->props->fb_blank = *(int *)evdata->data;
-                        if (likely(bd->props && bd->props->update_status))
-                                bd->props->update_status(bd);
-                }
-        up(&bd->sem);
-        return 0;
-}
-
 /**
  * backlight_device_register - create and register a new object of
  *   backlight_device class.
@@ -215,10 +241,7 @@ error:		kfree(new_bd);
                 return ERR_PTR(rc);
         }
 
-        memset(&new_bd->fb_notif, 0, sizeof(new_bd->fb_notif));
-        new_bd->fb_notif.notifier_call = fb_notifier_callback;
-
-        rc = fb_register_client(&new_bd->fb_notif);
+        rc = backlight_register_fb(new_bd);
         if (unlikely(rc))
                 goto error;
 
@@ -268,7 +291,7 @@ void backlight_device_unregister(struct backlight_device *bd)
         bd->props = NULL;
         up(&bd->sem);
 
-        fb_unregister_client(&bd->fb_notif);
+        backlight_unregister_fb(bd);
 
         class_device_unregister(&bd->class_dev);
 }