1 files changed, 35 insertions, 125 deletions

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 86e1cdc8e369..9dc93c5e480b 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -15,7 +15,6 @@
 #include <linux/notifier.h>
 #include <linux/ctype.h>
 #include <linux/err.h>
-#include <linux/fb.h>
 #include <linux/slab.h>
 
 #ifdef CONFIG_PMAC_BACKLIGHT
@@ -57,15 +56,14 @@
  * a hot-key to adjust backlight, the driver must notify the backlight
  * core that brightness has changed using backlight_force_update().
  *
- * The backlight driver core receives notifications from fbdev and
- * if the event is FB_EVENT_BLANK and if the value of blank, from the
- * FBIOBLANK ioctrl, results in a change in the backlight state the
- * update_status() operation is called.
+ * Display drives can control the backlight device's status using
+ * backlight_notify_blank() and backlight_notify_blank_all(). If this
+ * results in a change in the backlight state the functions call the
+ * update_status() operation.
  */
 
 static struct list_head backlight_dev_list;
 static struct mutex backlight_dev_list_mutex;
-static struct blocking_notifier_head backlight_notifier;
 
 static const char *const backlight_types[] = {
 	[BACKLIGHT_RAW] = "raw",
@@ -79,83 +77,40 @@ static const char *const backlight_scale_types[] = {
 	[BACKLIGHT_SCALE_NON_LINEAR]	= "non-linear",
 };
 
-#if defined(CONFIG_FB_CORE) || (defined(CONFIG_FB_CORE_MODULE) && \
-				defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
-/*
- * fb_notifier_callback
- *
- * This callback gets called when something important happens inside a
- * framebuffer driver. The backlight core only cares about FB_BLANK_UNBLANK
- * which is reported to the driver using backlight_update_status()
- * as a state change.
- *
- * There may be several fbdev's connected to the backlight device,
- * in which case they are kept track of. A state change is only reported
- * if there is a change in backlight for the specified fbdev.
- */
-static int fb_notifier_callback(struct notifier_block *self,
-				unsigned long event, void *data)
+void backlight_notify_blank(struct backlight_device *bd, struct device *display_dev,
+			    bool fb_on, bool prev_fb_on)
 {
-	struct backlight_device *bd;
-	struct fb_event *evdata = data;
-	int node = evdata->info->node;
-	int fb_blank = 0;
-
-	/* 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);
-	mutex_lock(&bd->ops_lock);
+	guard(mutex)(&bd->ops_lock);
 
 	if (!bd->ops)
-		goto out;
-	if (bd->ops->check_fb && !bd->ops->check_fb(bd, evdata->info))
-		goto out;
+		return;
+	if (bd->ops->controls_device && !bd->ops->controls_device(bd, display_dev))
+		return;
 
-	fb_blank = *(int *)evdata->data;
-	if (fb_blank == FB_BLANK_UNBLANK && !bd->fb_bl_on[node]) {
-		bd->fb_bl_on[node] = true;
+	if (fb_on && (!prev_fb_on || !bd->use_count)) {
 		if (!bd->use_count++) {
 			bd->props.state &= ~BL_CORE_FBBLANK;
-			bd->props.fb_blank = FB_BLANK_UNBLANK;
 			backlight_update_status(bd);
 		}
-	} else if (fb_blank != FB_BLANK_UNBLANK && bd->fb_bl_on[node]) {
-		bd->fb_bl_on[node] = false;
+	} else if (!fb_on && prev_fb_on && bd->use_count) {
 		if (!(--bd->use_count)) {
 			bd->props.state |= BL_CORE_FBBLANK;
-			bd->props.fb_blank = fb_blank;
 			backlight_update_status(bd);
 		}
 	}
-out:
-	mutex_unlock(&bd->ops_lock);
-	return 0;
 }
+EXPORT_SYMBOL(backlight_notify_blank);
 
-static int backlight_register_fb(struct backlight_device *bd)
+void backlight_notify_blank_all(struct device *display_dev, bool fb_on, bool prev_fb_on)
 {
-	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
-	bd->fb_notif.notifier_call = fb_notifier_callback;
-
-	return fb_register_client(&bd->fb_notif);
-}
+	struct backlight_device *bd;
 
-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;
-}
+	guard(mutex)(&backlight_dev_list_mutex);
 
-static inline void backlight_unregister_fb(struct backlight_device *bd)
-{
+	list_for_each_entry(bd, &backlight_dev_list, entry)
+		backlight_notify_blank(bd, display_dev, fb_on, prev_fb_on);
 }
-#endif /* CONFIG_FB_CORE */
+EXPORT_SYMBOL(backlight_notify_blank_all);
 
 static void backlight_generate_event(struct backlight_device *bd,
 				     enum backlight_update_reason reason)
@@ -317,8 +272,6 @@ static ssize_t scale_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(scale);
 
-static struct class *backlight_class;
-
 #ifdef CONFIG_PM_SLEEP
 static int backlight_suspend(struct device *dev)
 {
@@ -369,6 +322,12 @@ static struct attribute *bl_device_attrs[] = {
 };
 ATTRIBUTE_GROUPS(bl_device);
 
+static const struct class backlight_class = {
+	.name = "backlight",
+	.dev_groups = bl_device_groups,
+	.pm = &backlight_class_dev_pm_ops,
+};
+
 /**
  * backlight_force_update - tell the backlight subsystem that hardware state
  *   has changed
@@ -418,7 +377,7 @@ struct backlight_device *backlight_device_register(const char *name,
 	mutex_init(&new_bd->update_lock);
 	mutex_init(&new_bd->ops_lock);
 
-	new_bd->dev.class = backlight_class;
+	new_bd->dev.class = &backlight_class;
 	new_bd->dev.parent = parent;
 	new_bd->dev.release = bl_device_release;
 	dev_set_name(&new_bd->dev, "%s", name);
@@ -442,12 +401,6 @@ struct backlight_device *backlight_device_register(const char *name,
 		return ERR_PTR(rc);
 	}
 
-	rc = backlight_register_fb(new_bd);
-	if (rc) {
-		device_unregister(&new_bd->dev);
-		return ERR_PTR(rc);
-	}
-
 	new_bd->ops = ops;
 
 #ifdef CONFIG_PMAC_BACKLIGHT
@@ -461,9 +414,6 @@ struct backlight_device *backlight_device_register(const char *name,
 	list_add(&new_bd->entry, &backlight_dev_list);
 	mutex_unlock(&backlight_dev_list_mutex);
 
-	blocking_notifier_call_chain(&backlight_notifier,
-				     BACKLIGHT_REGISTERED, new_bd);
-
 	return new_bd;
 }
 EXPORT_SYMBOL(backlight_device_register);
@@ -510,7 +460,7 @@ struct backlight_device *backlight_device_get_by_name(const char *name)
 {
 	struct device *dev;
 
-	dev = class_find_device_by_name(backlight_class, name);
+	dev = class_find_device_by_name(&backlight_class, name);
 
 	return dev ? to_backlight_device(dev) : NULL;
 }
@@ -533,14 +483,10 @@ void backlight_device_unregister(struct backlight_device *bd)
 	mutex_unlock(&pmac_backlight_mutex);
 #endif
 
-	blocking_notifier_call_chain(&backlight_notifier,
-				     BACKLIGHT_UNREGISTERED, bd);
-
 	mutex_lock(&bd->ops_lock);
 	bd->ops = NULL;
 	mutex_unlock(&bd->ops_lock);
 
-	backlight_unregister_fb(bd);
 	device_unregister(&bd->dev);
 }
 EXPORT_SYMBOL(backlight_device_unregister);
@@ -561,40 +507,6 @@ static int devm_backlight_device_match(struct device *dev, void *res,
 }
 
 /**
- * backlight_register_notifier - get notified of backlight (un)registration
- * @nb: notifier block with the notifier to call on backlight (un)registration
- *
- * Register a notifier to get notified when backlight devices get registered
- * or unregistered.
- *
- * RETURNS:
- *
- * 0 on success, otherwise a negative error code
- */
-int backlight_register_notifier(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_register(&backlight_notifier, nb);
-}
-EXPORT_SYMBOL(backlight_register_notifier);
-
-/**
- * backlight_unregister_notifier - unregister a backlight notifier
- * @nb: notifier block to unregister
- *
- * Register a notifier to get notified when backlight devices get registered
- * or unregistered.
- *
- * RETURNS:
- *
- * 0 on success, otherwise a negative error code
- */
-int backlight_unregister_notifier(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_unregister(&backlight_notifier, nb);
-}
-EXPORT_SYMBOL(backlight_unregister_notifier);
-
-/**
  * devm_backlight_device_register - register a new backlight device
  * @dev: the device to register
  * @name: the name of the device
@@ -678,7 +590,7 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node)
 {
 	struct device *dev;
 
-	dev = class_find_device(backlight_class, NULL, node, of_parent_match);
+	dev = class_find_device(&backlight_class, NULL, node, of_parent_match);
 
 	return dev ? to_backlight_device(dev) : NULL;
 }
@@ -746,23 +658,21 @@ EXPORT_SYMBOL(devm_of_find_backlight);
 
 static void __exit backlight_class_exit(void)
 {
-	class_destroy(backlight_class);
+	class_unregister(&backlight_class);
 }
 
 static int __init backlight_class_init(void)
 {
-	backlight_class = class_create("backlight");
-	if (IS_ERR(backlight_class)) {
-		pr_warn("Unable to create backlight class; errno = %ld\n",
-			PTR_ERR(backlight_class));
-		return PTR_ERR(backlight_class);
+	int ret;
+
+	ret = class_register(&backlight_class);
+	if (ret) {
+		pr_warn("Unable to create backlight class; errno = %d\n", ret);
+		return ret;
 	}
 
-	backlight_class->dev_groups = bl_device_groups;
-	backlight_class->pm = &backlight_class_dev_pm_ops;
 	INIT_LIST_HEAD(&backlight_dev_list);
 	mutex_init(&backlight_dev_list_mutex);
-	BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier);
 
 	return 0;
 }