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path: root/drivers/video/backlight/backlight.c
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Diffstat (limited to 'drivers/video/backlight/backlight.c')
-rw-r--r--drivers/video/backlight/backlight.c95
1 files changed, 56 insertions, 39 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 27597c576eff..db8c191b1201 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;
@@ -142,7 +195,7 @@ static struct class backlight_class = {
.store = _store, \
}
-static struct class_device_attribute bl_class_device_attributes[] = {
+static const struct class_device_attribute bl_class_device_attributes[] = {
DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
backlight_store_brightness),
@@ -151,33 +204,6 @@ static 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;
@@ -259,16 +282,10 @@ void backlight_device_unregister(struct backlight_device *bd)
&bl_class_device_attributes[i]);
down(&bd->sem);
- if (likely(bd->props && bd->props->update_status)) {
- bd->props->brightness = 0;
- bd->props->power = 0;
- bd->props->update_status(bd);
- }
-
bd->props = NULL;
up(&bd->sem);
- fb_unregister_client(&bd->fb_notif);
+ backlight_unregister_fb(bd);
class_device_unregister(&bd->class_dev);
}