[PATCH v3 00/11] backlight, lcd, led: Remove fbdev dependencies

@@ -339,11 +339,13 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 }
 EXPORT_SYMBOL(fb_set_var);
 
-int
-fb_blank(struct fb_info *info, int blank)
+int fb_blank(struct fb_info *info, int blank)
 {
 	struct fb_event event;
-	int ret = -EINVAL;
+	int ret;
+
+	if (!info->fbops->fb_blank)
+		return -EINVAL;
 
 	if (blank > FB_BLANK_POWERDOWN)
 		blank = FB_BLANK_POWERDOWN;

@@ -351,13 +353,13 @@ fb_blank(struct fb_info *info, int blank)
 	event.info = info;
 	event.data = ␣
 
-	if (info->fbops->fb_blank)
-		ret = info->fbops->fb_blank(blank, info);
+	ret = info->fbops->fb_blank(blank, info);
+	if (ret)
+		return ret;
 
-	if (!ret)
-		fb_notifier_call_chain(FB_EVENT_BLANK, &event);
+	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(fb_blank);
 

@@ -343,6 +343,7 @@ int fb_blank(struct fb_info *info, int blank)
 {
 	int old_blank = info->blank;
 	struct fb_event event;
+	int data[2];
 	int ret;
 
 	if (!info->fbops->fb_blank)

@@ -351,8 +352,10 @@ int fb_blank(struct fb_info *info, int blank)
 	if (blank > FB_BLANK_POWERDOWN)
 		blank = FB_BLANK_POWERDOWN;
 
+	data[0] = blank;
+	data[1] = old_blank;
 	event.info = info;
-	event.data = ␣
+	event.data = data;
 
 	info->blank = blank;
 

@@ -42,6 +42,7 @@ struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
 
 	info->device = dev;
 	info->fbcon_rotate_hint = -1;
+	info->blank = FB_BLANK_UNBLANK;
 
 #if IS_ENABLED(CONFIG_FB_BACKLIGHT)
 	mutex_init(&info->bl_curve_mutex);

@@ -341,6 +341,7 @@ EXPORT_SYMBOL(fb_set_var);
 
 int fb_blank(struct fb_info *info, int blank)
 {
+	int old_blank = info->blank;
 	struct fb_event event;
 	int ret;
 

@@ -353,13 +354,19 @@ int fb_blank(struct fb_info *info, int blank)
 	event.info = info;
 	event.data = ␣
 
+	info->blank = blank;
+
 	ret = info->fbops->fb_blank(blank, info);
 	if (ret)
-		return ret;
+		goto err;
 
 	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 
 	return 0;
+
+err:
+	info->blank = old_blank;
+	return ret;
 }
 EXPORT_SYMBOL(fb_blank);
 

@@ -408,6 +415,14 @@ static int do_register_framebuffer(struct fb_info *fb_info)
 	mutex_init(&fb_info->lock);
 	mutex_init(&fb_info->mm_lock);
 
+	/*
+	 * With an fb_blank callback present, we assume that the
+	 * display is blank, so that fb_blank() enables it on the
+	 * first modeset.
+	 */
+	if (fb_info->fbops->fb_blank)
+		fb_info->blank = FB_BLANK_POWERDOWN;
+
 	fb_device_create(fb_info);
 
 	if (fb_info->pixmap.addr == NULL) {

@@ -242,11 +242,11 @@ static ssize_t store_blank(struct device *device,
 	return count;
 }
 
-static ssize_t show_blank(struct device *device,
-			  struct device_attribute *attr, char *buf)
+static ssize_t show_blank(struct device *device, struct device_attribute *attr, char *buf)
 {
-//	struct fb_info *fb_info = dev_get_drvdata(device);
-	return 0;
+	struct fb_info *fb_info = dev_get_drvdata(device);
+
+	return sysfs_emit(buf, "%d\n", fb_info->blank);
 }
 
 static ssize_t store_console(struct device *device,

@@ -471,6 +471,8 @@ struct fb_info {
 	struct list_head modelist;      /* mode list */
 	struct fb_videomode *mode;	/* current mode */
 
+	int blank; /* current blanking; see FB_BLANK_ constants */
+
 #if IS_ENABLED(CONFIG_FB_BACKLIGHT)
 	/* assigned backlight device */
 	/* set before framebuffer registration,

@@ -80,6 +80,30 @@ static const char *const backlight_scale_types[] = {
 
 #if defined(CONFIG_FB_CORE) || (defined(CONFIG_FB_CORE_MODULE) && \
 				defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
+static void backlight_notify_blank(struct backlight_device *bd,
+				   struct device *display_dev,
+				   bool fb_on, bool prev_fb_on)
+{
+	guard(mutex)(&bd->ops_lock);
+
+	if (!bd->ops)
+		return;
+	if (bd->ops->controls_device && !bd->ops->controls_device(bd, display_dev))
+		return;
+
+	if (fb_on && (!prev_fb_on || !bd->use_count)) {
+		if (!bd->use_count++) {
+			bd->props.state &= ~BL_CORE_FBBLANK;
+			backlight_update_status(bd);
+		}
+	} else if (!fb_on && prev_fb_on && bd->use_count) {
+		if (!(--bd->use_count)) {
+			bd->props.state |= BL_CORE_FBBLANK;
+			backlight_update_status(bd);
+		}
+	}
+}
+
 /*
  * fb_notifier_callback
  *

@@ -107,31 +131,15 @@ static int fb_notifier_callback(struct notifier_block *self,
 		return 0;
 
 	bd = container_of(self, struct backlight_device, fb_notif);
-	mutex_lock(&bd->ops_lock);
 
-	if (!bd->ops)
-		goto out;
-	if (bd->ops->controls_device && !bd->ops->controls_device(bd, info->device))
-		goto out;
 	if (fb_bd && fb_bd != bd)
-		goto out;
+		return 0;
 
 	fb_on = fb_blank[0] == FB_BLANK_UNBLANK;
 	prev_fb_on = fb_blank[1] == FB_BLANK_UNBLANK;
 
-	if (fb_on && (!prev_fb_on || !bd->use_count)) {
-		if (!bd->use_count++) {
-			bd->props.state &= ~BL_CORE_FBBLANK;
-			backlight_update_status(bd);
-		}
-	} else if (!fb_on && prev_fb_on && bd->use_count) {
-		if (!(--bd->use_count)) {
-			bd->props.state |= BL_CORE_FBBLANK;
-			backlight_update_status(bd);
-		}
-	}
-out:
-	mutex_unlock(&bd->ops_lock);
+	backlight_notify_blank(bd, info->device, fb_on, prev_fb_on);
+
 	return 0;
 }
 

@@ -98,9 +98,9 @@ static int fb_notifier_callback(struct notifier_block *self,
 	struct backlight_device *bd;
 	struct fb_event *evdata = data;
 	struct fb_info *info = evdata->info;
+	const int *fb_blank = evdata->data;
 	struct backlight_device *fb_bd = fb_bl_device(info);
-	int node = info->node;
-	int fb_blank = 0;
+	bool fb_on, prev_fb_on;
 
 	/* If we aren't interested in this event, skip it immediately ... */
 	if (event != FB_EVENT_BLANK)

@@ -116,15 +116,15 @@ static int fb_notifier_callback(struct notifier_block *self,
 	if (fb_bd && fb_bd != bd)
 		goto out;
 
-	fb_blank = *(int *)evdata->data;
-	if (fb_blank == FB_BLANK_UNBLANK && !bd->fb_bl_on[node]) {
-		bd->fb_bl_on[node] = true;
+	fb_on = fb_blank[0] == FB_BLANK_UNBLANK;
+	prev_fb_on = fb_blank[1] == FB_BLANK_UNBLANK;
+
+	if (fb_on && (!prev_fb_on || !bd->use_count)) {
 		if (!bd->use_count++) {
 			bd->props.state &= ~BL_CORE_FBBLANK;
 			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;
 			backlight_update_status(bd);

@@ -294,15 +294,7 @@ struct backlight_device {
 	struct device dev;
 
 	/**
-	 * @fb_bl_on: The state of individual fbdev's.
-	 *
-	 * Multiple fbdev's may share one backlight device. The fb_bl_on
-	 * records the state of the individual fbdev.
-	 */
-	bool fb_bl_on[FB_MAX];
-
-	/**
-	 * @use_count: The number of uses of fb_bl_on.
+	 * @use_count: The number of unblanked displays.
 	 */
 	int use_count;
 };

@@ -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

@@ -57,10 +56,10 @@
  * 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;

@@ -78,11 +77,8 @@ 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))
-static void backlight_notify_blank(struct backlight_device *bd,
-				   struct device *display_dev,
-				   bool fb_on, bool prev_fb_on)
+void backlight_notify_blank(struct backlight_device *bd, struct device *display_dev,
+			    bool fb_on, bool prev_fb_on)
 {
 	guard(mutex)(&bd->ops_lock);
 

@@ -103,68 +99,18 @@ static void backlight_notify_blank(struct backlight_device *bd,
 		}
 	}
 }
+EXPORT_SYMBOL(backlight_notify_blank);
 
-/*
- * 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_all(struct device *display_dev, bool fb_on, bool prev_fb_on)
 {
 	struct backlight_device *bd;
-	struct fb_event *evdata = data;
-	struct fb_info *info = evdata->info;
-	const int *fb_blank = evdata->data;
-	struct backlight_device *fb_bd = fb_bl_device(info);
-	bool fb_on, prev_fb_on;
-
-	/* 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);
-
-	if (fb_bd && fb_bd != bd)
-		return 0;
-
-	fb_on = fb_blank[0] == FB_BLANK_UNBLANK;
-	prev_fb_on = fb_blank[1] == FB_BLANK_UNBLANK;
-
-	backlight_notify_blank(bd, info->device, fb_on, prev_fb_on);
-
-	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);
-}
+	guard(mutex)(&backlight_dev_list_mutex);
 
-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;
+	list_for_each_entry(bd, &backlight_dev_list, entry)
+		backlight_notify_blank(bd, display_dev, fb_on, prev_fb_on);
 }
-
-static inline void backlight_unregister_fb(struct backlight_device *bd)
-{
-}
-#endif /* CONFIG_FB_CORE */
+EXPORT_SYMBOL(backlight_notify_blank_all);
 
 static void backlight_generate_event(struct backlight_device *bd,
 				     enum backlight_update_reason reason)

@@ -455,12 +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

@@ -547,7 +487,6 @@ void backlight_device_unregister(struct backlight_device *bd)
 	bd->ops = NULL;
 	mutex_unlock(&bd->ops_lock);
 
-	backlight_unregister_fb(bd);
 	device_unregister(&bd->dev);
 }
 EXPORT_SYMBOL(backlight_device_unregister);

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <linux/backlight.h>
 #include <linux/export.h>
 #include <linux/fb.h>
 #include <linux/mutex.h>

@@ -36,4 +37,15 @@ struct backlight_device *fb_bl_device(struct fb_info *info)
 	return info->bl_dev;
 }
 EXPORT_SYMBOL(fb_bl_device);
+
+void fb_bl_notify_blank(struct fb_info *info, int old_blank)
+{
+	bool on = info->blank == FB_BLANK_UNBLANK;
+	bool prev_on = old_blank == FB_BLANK_UNBLANK;
+
+	if (info->bl_dev)
+		backlight_notify_blank(info->bl_dev, info->device, on, prev_on);
+	else
+		backlight_notify_blank_all(info->device, on, prev_on);
+}
 #endif

@@ -363,6 +363,8 @@ int fb_blank(struct fb_info *info, int blank)
 	if (ret)
 		goto err;
 
+	fb_bl_notify_blank(info, old_blank);
+
 	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 
 	return 0;

@@ -12,7 +12,6 @@
 #include <linux/device.h>
 #include <linux/fb.h>
 #include <linux/mutex.h>
-#include <linux/notifier.h>
 #include <linux/types.h>
 
 /**

@@ -278,11 +277,6 @@ struct backlight_device {
 	 */
 	const struct backlight_ops *ops;
 
-	/**
-	 * @fb_notif: The framebuffer notifier block
-	 */
-	struct notifier_block fb_notif;
-
 	/**
 	 * @entry: List entry of all registered backlight devices
 	 */

@@ -400,6 +394,12 @@ struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
 int backlight_device_set_brightness(struct backlight_device *bd,
 				    unsigned long brightness);
 
+void backlight_notify_blank(struct backlight_device *bd,
+			    struct device *display_dev,
+			    bool fb_on, bool prev_fb_on);
+void backlight_notify_blank_all(struct device *display_dev,
+				bool fb_on, bool prev_fb_on);
+
 #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
 
 /**

@@ -757,11 +757,15 @@ extern void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
 
 #if IS_ENABLED(CONFIG_FB_BACKLIGHT)
 struct backlight_device *fb_bl_device(struct fb_info *info);
+void fb_bl_notify_blank(struct fb_info *info, int old_blank);
 #else
 static inline struct backlight_device *fb_bl_device(struct fb_info *info)
 {
 	return NULL;
 }
+
+static inline void fb_bl_notify_blank(struct fb_info *info, int old_blank)
+{ }
 #endif
 
 static inline struct lcd_device *fb_lcd_device(struct fb_info *info)

@@ -18,6 +18,32 @@
 #include <linux/fb.h>
 #include <linux/slab.h>
 
+static void lcd_notify_blank(struct lcd_device *ld, struct device *display_dev,
+			     int power)
+{
+	guard(mutex)(&ld->ops_lock);
+
+	if (!ld->ops || !ld->ops->set_power)
+		return;
+	if (ld->ops->controls_device && !ld->ops->controls_device(ld, display_dev))
+		return;
+
+	ld->ops->set_power(ld, power);
+}
+
+static void lcd_notify_mode_change(struct lcd_device *ld, struct device *display_dev,
+				   unsigned int width, unsigned int height)
+{
+	guard(mutex)(&ld->ops_lock);
+
+	if (!ld->ops || !ld->ops->set_mode)
+		return;
+	if (ld->ops->controls_device && !ld->ops->controls_device(ld, display_dev))
+		return;
+
+	ld->ops->set_mode(ld, width, height);
+}
+
 #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
 			   defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
 static int to_lcd_power(int fb_blank)

@@ -50,25 +76,17 @@ static int fb_notifier_callback(struct notifier_block *self,
 	struct fb_info *info = evdata->info;
 	struct lcd_device *fb_lcd = fb_lcd_device(info);
 
-	guard(mutex)(&ld->ops_lock);
-
-	if (!ld->ops)
-		return 0;
-	if (ld->ops->controls_device && !ld->ops->controls_device(ld, info->device))
-		return 0;
 	if (fb_lcd && fb_lcd != ld)
 		return 0;
 
 	if (event == FB_EVENT_BLANK) {
 		int power = to_lcd_power(*(int *)evdata->data);
 
-		if (ld->ops->set_power)
-			ld->ops->set_power(ld, power);
+		lcd_notify_blank(ld, info->device, power);
 	} else {
 		const struct fb_videomode *videomode = evdata->data;
 
-		if (ld->ops->set_mode)
-			ld->ops->set_mode(ld, videomode->xres, videomode->yres);
+		lcd_notify_mode_change(ld, info->device, videomode->xres, videomode->yres);
 	}
 
 	return 0;

@@ -25,12 +25,28 @@ struct bl_trig_notifier {
 	unsigned invert;
 };
 
+static void ledtrig_backlight_notify_blank(struct bl_trig_notifier *n, int new_status)
+{
+	struct led_classdev *led = n->led;
+
+	if (new_status == n->old_status)
+		return;
+
+	if ((n->old_status == UNBLANK) ^ n->invert) {
+		n->brightness = led->brightness;
+		led_set_brightness_nosleep(led, LED_OFF);
+	} else {
+		led_set_brightness_nosleep(led, n->brightness);
+	}
+
+	n->old_status = new_status;
+}
+
 static int fb_notifier_callback(struct notifier_block *p,
 				unsigned long event, void *data)
 {
 	struct bl_trig_notifier *n = container_of(p,
 					struct bl_trig_notifier, notifier);
-	struct led_classdev *led = n->led;
 	struct fb_event *fb_event = data;
 	int *blank;
 	int new_status;

@@ -42,17 +58,7 @@ static int fb_notifier_callback(struct notifier_block *p,
 	blank = fb_event->data;
 	new_status = *blank ? BLANK : UNBLANK;
 
-	if (new_status == n->old_status)
-		return 0;
-
-	if ((n->old_status == UNBLANK) ^ n->invert) {
-		n->brightness = led->brightness;
-		led_set_brightness_nosleep(led, LED_OFF);
-	} else {
-		led_set_brightness_nosleep(led, n->brightness);
-	}
-
-	n->old_status = new_status;
+	ledtrig_backlight_notify_blank(n, new_status);
 
 	return 0;
 }

@@ -15,9 +15,11 @@
 #include <linux/notifier.h>
 #include <linux/ctype.h>
 #include <linux/err.h>
-#include <linux/fb.h>
 #include <linux/slab.h>
 
+static DEFINE_MUTEX(lcd_dev_list_mutex);
+static LIST_HEAD(lcd_dev_list);
+
 static void lcd_notify_blank(struct lcd_device *ld, struct device *display_dev,
 			     int power)
 {

@@ -31,6 +33,17 @@ static void lcd_notify_blank(struct lcd_device *ld, struct device *display_dev,
 	ld->ops->set_power(ld, power);
 }
 
+void lcd_notify_blank_all(struct device *display_dev, int power)
+{
+	struct lcd_device *ld;
+
+	guard(mutex)(&lcd_dev_list_mutex);
+
+	list_for_each_entry(ld, &lcd_dev_list, entry)
+		lcd_notify_blank(ld, display_dev, power);
+}
+EXPORT_SYMBOL(lcd_notify_blank_all);
+
 static void lcd_notify_mode_change(struct lcd_device *ld, struct device *display_dev,
 				   unsigned int width, unsigned int height)
 {

@@ -44,75 +57,17 @@ static void lcd_notify_mode_change(struct lcd_device *ld, struct device *display
 	ld->ops->set_mode(ld, width, height);
 }
 
-#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
-			   defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
-static int to_lcd_power(int fb_blank)
+void lcd_notify_mode_change_all(struct device *display_dev,
+				unsigned int width, unsigned int height)
 {
-	switch (fb_blank) {
-	case FB_BLANK_UNBLANK:
-		return LCD_POWER_ON;
-	/* deprecated; TODO: should become 'off' */
-	case FB_BLANK_NORMAL:
-		return LCD_POWER_REDUCED;
-	case FB_BLANK_VSYNC_SUSPEND:
-		return LCD_POWER_REDUCED_VSYNC_SUSPEND;
-	/* 'off' */
-	case FB_BLANK_HSYNC_SUSPEND:
-	case FB_BLANK_POWERDOWN:
-	default:
-		return LCD_POWER_OFF;
-	}
-}
+	struct lcd_device *ld;
 
-/* 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 lcd power as well ...
- */
-static int fb_notifier_callback(struct notifier_block *self,
-				 unsigned long event, void *data)
-{
-	struct lcd_device *ld = container_of(self, struct lcd_device, fb_notif);
-	struct fb_event *evdata = data;
-	struct fb_info *info = evdata->info;
-	struct lcd_device *fb_lcd = fb_lcd_device(info);
-
-	if (fb_lcd && fb_lcd != ld)
-		return 0;
-
-	if (event == FB_EVENT_BLANK) {
-		int power = to_lcd_power(*(int *)evdata->data);
-
-		lcd_notify_blank(ld, info->device, power);
-	} else {
-		const struct fb_videomode *videomode = evdata->data;
-
-		lcd_notify_mode_change(ld, info->device, videomode->xres, videomode->yres);
-	}
+	guard(mutex)(&lcd_dev_list_mutex);
 
-	return 0;
+	list_for_each_entry(ld, &lcd_dev_list, entry)
+		lcd_notify_mode_change(ld, display_dev, width, height);
 }
-
-static int lcd_register_fb(struct lcd_device *ld)
-{
-	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
-	ld->fb_notif.notifier_call = fb_notifier_callback;
-	return fb_register_client(&ld->fb_notif);
-}
-
-static void lcd_unregister_fb(struct lcd_device *ld)
-{
-	fb_unregister_client(&ld->fb_notif);
-}
-#else
-static int lcd_register_fb(struct lcd_device *ld)
-{
-	return 0;
-}
-
-static inline void lcd_unregister_fb(struct lcd_device *ld)
-{
-}
-#endif /* CONFIG_FB */
+EXPORT_SYMBOL(lcd_notify_mode_change_all);
 
 static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr,
 		char *buf)

@@ -263,11 +218,8 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 		return ERR_PTR(rc);
 	}
 
-	rc = lcd_register_fb(new_ld);
-	if (rc) {
-		device_unregister(&new_ld->dev);
-		return ERR_PTR(rc);
-	}
+	guard(mutex)(&lcd_dev_list_mutex);
+	list_add(&new_ld->entry, &lcd_dev_list);
 
 	return new_ld;
 }

@@ -284,10 +236,12 @@ void lcd_device_unregister(struct lcd_device *ld)
 	if (!ld)
 		return;
 
+	guard(mutex)(&lcd_dev_list_mutex);
+	list_del(&ld->entry);
+
 	mutex_lock(&ld->ops_lock);
 	ld->ops = NULL;
 	mutex_unlock(&ld->ops_lock);
-	lcd_unregister_fb(ld);
 
 	device_unregister(&ld->dev);
 }

@@ -15,6 +15,7 @@
 #include <linux/export.h>
 #include <linux/fb.h>
 #include <linux/fbcon.h>
+#include <linux/lcd.h>
 
 #include <video/nomodeset.h>
 

@@ -220,6 +221,12 @@ static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
 	return err;
 }
 
+static void fb_lcd_notify_mode_change(struct fb_info *info,
+				      struct fb_videomode *mode)
+{
+	lcd_notify_mode_change_all(info->device, mode->xres, mode->yres);
+}
+
 int
 fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 {

@@ -227,7 +234,6 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 	u32 activate;
 	struct fb_var_screeninfo old_var;
 	struct fb_videomode mode;
-	struct fb_event event;
 	u32 unused;
 
 	if (var->activate & FB_ACTIVATE_INV_MODE) {

@@ -331,14 +337,38 @@ fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
 	if (ret)
 		return ret;
 
-	event.info = info;
-	event.data = &mode;
-	fb_notifier_call_chain(FB_EVENT_MODE_CHANGE, &event);
+	fb_lcd_notify_mode_change(info, &mode);
 
 	return 0;
 }
 EXPORT_SYMBOL(fb_set_var);
 
+static void fb_lcd_notify_blank(struct fb_info *info)
+{
+	int power;
+
+	switch (info->blank) {
+	case FB_BLANK_UNBLANK:
+		power = LCD_POWER_ON;
+		break;
+	/* deprecated; TODO: should become 'off' */
+	case FB_BLANK_NORMAL:
+		power = LCD_POWER_REDUCED;
+		break;
+	case FB_BLANK_VSYNC_SUSPEND:
+		power = LCD_POWER_REDUCED_VSYNC_SUSPEND;
+		break;
+	/* 'off' */
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_POWERDOWN:
+	default:
+		power = LCD_POWER_OFF;
+		break;
+	}
+
+	lcd_notify_blank_all(info->device, power);
+}
+
 int fb_blank(struct fb_info *info, int blank)
 {
 	int old_blank = info->blank;

@@ -364,6 +394,7 @@ int fb_blank(struct fb_info *info, int blank)
 		goto err;
 
 	fb_bl_notify_blank(info, old_blank);
+	fb_lcd_notify_blank(info);
 
 	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
 

@@ -11,7 +11,6 @@
 
 #include <linux/device.h>
 #include <linux/mutex.h>
-#include <linux/notifier.h>
 
 #define LCD_POWER_ON			(0)
 #define LCD_POWER_REDUCED		(1) // deprecated; don't use in new code

@@ -79,8 +78,11 @@ struct lcd_device {
 	const struct lcd_ops *ops;
 	/* Serialise access to set_power method */
 	struct mutex update_lock;
-	/* The framebuffer notifier block */
-	struct notifier_block fb_notif;
+
+	/**
+	 * @entry: List entry of all registered lcd devices
+	 */
+	struct list_head entry;
 
 	struct device dev;
 };

@@ -125,6 +127,19 @@ extern void lcd_device_unregister(struct lcd_device *ld);
 extern void devm_lcd_device_unregister(struct device *dev,
 	struct lcd_device *ld);
 
+#if IS_REACHABLE(CONFIG_LCD_CLASS_DEVICE)
+void lcd_notify_blank_all(struct device *display_dev, int power);
+void lcd_notify_mode_change_all(struct device *display_dev,
+				unsigned int width, unsigned int height);
+#else
+static inline void lcd_notify_blank_all(struct device *display_dev, int power)
+{}
+
+static inline void lcd_notify_mode_change_all(struct device *display_dev,
+					      unsigned int width, unsigned int height)
+{}
+#endif
+
 #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
 
 static inline void * lcd_get_data(struct lcd_device *ld_dev)

@@ -10,7 +10,6 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/init.h>
-#include <linux/fb.h>
 #include <linux/leds.h>
 #include "../leds.h"
 

@@ -21,10 +20,14 @@ struct bl_trig_notifier {
 	struct led_classdev *led;
 	int brightness;
 	int old_status;
-	struct notifier_block notifier;
 	unsigned invert;
+
+	struct list_head entry;
 };
 
+static DEFINE_MUTEX(ledtrig_backlight_list_mutex);
+static LIST_HEAD(ledtrig_backlight_list);
+
 static void ledtrig_backlight_notify_blank(struct bl_trig_notifier *n, int new_status)
 {
 	struct led_classdev *led = n->led;

@@ -42,26 +45,17 @@ static void ledtrig_backlight_notify_blank(struct bl_trig_notifier *n, int new_s
 	n->old_status = new_status;
 }
 
-static int fb_notifier_callback(struct notifier_block *p,
-				unsigned long event, void *data)
+void ledtrig_backlight_blank(bool blank)
 {
-	struct bl_trig_notifier *n = container_of(p,
-					struct bl_trig_notifier, notifier);
-	struct fb_event *fb_event = data;
-	int *blank;
-	int new_status;
-
-	/* If we aren't interested in this event, skip it immediately ... */
-	if (event != FB_EVENT_BLANK)
-		return 0;
-
-	blank = fb_event->data;
-	new_status = *blank ? BLANK : UNBLANK;
+	struct bl_trig_notifier *n;
+	int new_status = blank ? BLANK : UNBLANK;
 
-	ledtrig_backlight_notify_blank(n, new_status);
+	guard(mutex)(&ledtrig_backlight_list_mutex);
 
-	return 0;
+	list_for_each_entry(n, &ledtrig_backlight_list, entry)
+		ledtrig_backlight_notify_blank(n, new_status);
 }
+EXPORT_SYMBOL(ledtrig_backlight_blank);
 
 static ssize_t bl_trig_invert_show(struct device *dev,
 		struct device_attribute *attr, char *buf)

@@ -106,8 +100,6 @@ ATTRIBUTE_GROUPS(bl_trig);
 
 static int bl_trig_activate(struct led_classdev *led)
 {
-	int ret;
-
 	struct bl_trig_notifier *n;
 
 	n = kzalloc(sizeof(struct bl_trig_notifier), GFP_KERNEL);

@@ -118,11 +110,9 @@ static int bl_trig_activate(struct led_classdev *led)
 	n->led = led;
 	n->brightness = led->brightness;
 	n->old_status = UNBLANK;
-	n->notifier.notifier_call = fb_notifier_callback;
 
-	ret = fb_register_client(&n->notifier);
-	if (ret)
-		dev_err(led->dev, "unable to register backlight trigger\n");
+	guard(mutex)(&ledtrig_backlight_list_mutex);
+	list_add(&n->entry, &ledtrig_backlight_list);
 
 	return 0;
 }

@@ -131,7 +121,9 @@ static void bl_trig_deactivate(struct led_classdev *led)
 {
 	struct bl_trig_notifier *n = led_get_trigger_data(led);
 
-	fb_unregister_client(&n->notifier);
+	guard(mutex)(&ledtrig_backlight_list_mutex);
+	list_del(&n->entry);
+
 	kfree(n);
 }
 

@@ -16,6 +16,7 @@
 #include <linux/fb.h>
 #include <linux/fbcon.h>
 #include <linux/lcd.h>
+#include <linux/leds.h>
 
 #include <video/nomodeset.h>
 

@@ -369,11 +370,17 @@ static void fb_lcd_notify_blank(struct fb_info *info)
 	lcd_notify_blank_all(info->device, power);
 }
 
+static void fb_ledtrig_backlight_notify_blank(struct fb_info *info)
+{
+	if (info->blank == FB_BLANK_UNBLANK)
+		ledtrig_backlight_blank(false);
+	else
+		ledtrig_backlight_blank(true);
+}
+
 int fb_blank(struct fb_info *info, int blank)
 {
 	int old_blank = info->blank;
-	struct fb_event event;
-	int data[2];
 	int ret;
 
 	if (!info->fbops->fb_blank)

@@ -382,11 +389,6 @@ int fb_blank(struct fb_info *info, int blank)
 	if (blank > FB_BLANK_POWERDOWN)
 		blank = FB_BLANK_POWERDOWN;
 
-	data[0] = blank;
-	data[1] = old_blank;
-	event.info = info;
-	event.data = data;
-
 	info->blank = blank;
 
 	ret = info->fbops->fb_blank(blank, info);

@@ -395,8 +397,7 @@ int fb_blank(struct fb_info *info, int blank)
 
 	fb_bl_notify_blank(info, old_blank);
 	fb_lcd_notify_blank(info);
-
-	fb_notifier_call_chain(FB_EVENT_BLANK, &event);
+	fb_ledtrig_backlight_notify_blank(info);
 
 	return 0;
 

@@ -640,6 +640,12 @@ static inline void ledtrig_flash_ctrl(bool on) {}
 static inline void ledtrig_torch_ctrl(bool on) {}
 #endif
 
+#if IS_REACHABLE(CONFIG_LEDS_TRIGGER_BACKLIGHT)
+void ledtrig_backlight_blank(bool blank);
+#else
+static inline void ledtrig_backlight_blank(bool blank) {}
+#endif
+
 /*
  * Generic LED platform data for describing LED names and default triggers.
  */

@@ -129,18 +129,12 @@ struct fb_cursor_user {
  * Register/unregister for framebuffer events
  */
 
-/*	The resolution of the passed in fb_info about to change */
-#define FB_EVENT_MODE_CHANGE		0x01
-
 #ifdef CONFIG_GUMSTIX_AM200EPD
 /* only used by mach-pxa/am200epd.c */
 #define FB_EVENT_FB_REGISTERED          0x05
 #define FB_EVENT_FB_UNREGISTERED        0x06
 #endif
 
-/*      A display blank is requested       */
-#define FB_EVENT_BLANK                  0x09
-
 struct fb_event {
 	struct fb_info *info;
 	void *data;