[PATCH 07/13] backlight: lcd: Maintain global list of lcd devices

[Thomas Zimmermann]

Maintain a list of lcd devices. This will replace the fbdev notifiers
that all lcd devices currently subscribe to.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/video/backlight/lcd.c | 11 +++++++++++
 include/linux/lcd.h           |  5 +++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 3267acf8dc5b..95a371b3e8a4 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -18,6 +18,9 @@
 #include <linux/fb.h>
 #include <linux/slab.h>
 
+static struct list_head lcd_dev_list;
+static struct mutex lcd_dev_list_mutex;
+
 #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
 			   defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
 static int to_lcd_power(int fb_blank)
@@ -251,6 +254,10 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 		return ERR_PTR(rc);
 	}
 
+	mutex_lock(&lcd_dev_list_mutex);
+	list_add(&new_ld->entry, &lcd_dev_list);
+	mutex_unlock(&lcd_dev_list_mutex);
+
 	return new_ld;
 }
 EXPORT_SYMBOL(lcd_device_register);
@@ -266,6 +273,10 @@ void lcd_device_unregister(struct lcd_device *ld)
 	if (!ld)
 		return;
 
+	mutex_lock(&lcd_dev_list_mutex);
+	list_del(&ld->entry);
+	mutex_unlock(&lcd_dev_list_mutex);
+
 	mutex_lock(&ld->ops_lock);
 	ld->ops = NULL;
 	mutex_unlock(&ld->ops_lock);
diff --git a/include/linux/lcd.h b/include/linux/lcd.h
index c3ccdff4519a..195b95edb13f 100644
--- a/include/linux/lcd.h
+++ b/include/linux/lcd.h
@@ -82,6 +82,11 @@ struct lcd_device {
 	/* The framebuffer notifier block */
 	struct notifier_block fb_notif;
 
+	/**
+	 * @entry: List entry of all registered lcd devices
+	 */
+	struct list_head entry;
+
 	struct device dev;
 };
 
-- 
2.48.1