2 * Backlight Lowlevel Control Abstraction
4 * Copyright (C) 2003,2004 Hewlett-Packard Company
8 #ifndef _LINUX_BACKLIGHT_H
9 #define _LINUX_BACKLIGHT_H
11 #include <linux/device.h>
12 #include <linux/notifier.h>
14 struct backlight_device;
17 /* This structure defines all the properties of a backlight
18 (usually attached to a LCD). */
19 struct backlight_properties {
20 /* Notify the backlight driver some property has changed */
21 int (*update_status)(struct backlight_device *);
22 /* Return the current backlight brightness (accounting for power,
24 int (*get_brightness)(struct backlight_device *);
25 /* Check if given framebuffer device is the one bound to this backlight;
26 return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
27 int (*check_fb)(struct fb_info *);
29 /* Current User requested brightness (0 - max_brightness) */
31 /* Maximal value for brightness (read-only) */
33 /* Current FB Power mode (0: full on, 1..3: power saving
34 modes; 4: full off), see FB_BLANK_XXX */
36 /* FB Blanking active? (values as for power) */
40 struct backlight_device {
41 /* This protects the 'props' field. If 'props' is NULL, the driver that
42 registered this device has been unloaded, and if class_get_devdata()
43 points to something in the body of that driver, it is also invalid. */
45 /* If this is NULL, the backing module is unloaded */
46 struct backlight_properties *props;
47 /* The framebuffer notifier block */
48 struct notifier_block fb_notif;
49 /* The class device structure */
50 struct class_device class_dev;
53 extern struct backlight_device *backlight_device_register(const char *name,
54 struct device *dev,void *devdata,struct backlight_properties *bp);
55 extern void backlight_device_unregister(struct backlight_device *bd);
57 #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev)