1 /* 2 * Backlight Lowlevel Control Abstraction 3 * 4 * Copyright (C) 2003,2004 Hewlett-Packard Company 5 * 6 */ 7 8 #ifndef _LINUX_BACKLIGHT_H 9 #define _LINUX_BACKLIGHT_H 10 11 #include <linux/device.h> 12 #include <linux/notifier.h> 13 14 struct backlight_device; 15 struct fb_info; 16 17 /* This structure defines all the properties of a backlight 18 (usually attached to a LCD). */ 19 struct backlight_properties { 20 /* Owner module */ 21 struct module *owner; 22 23 /* Notify the backlight driver some property has changed */ 24 int (*update_status)(struct backlight_device *); 25 /* Return the current backlight brightness (accounting for power, 26 fb_blank etc.) */ 27 int (*get_brightness)(struct backlight_device *); 28 /* Check if given framebuffer device is the one bound to this backlight; 29 return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */ 30 int (*check_fb)(struct fb_info *); 31 32 /* Current User requested brightness (0 - max_brightness) */ 33 int brightness; 34 /* Maximal value for brightness (read-only) */ 35 int max_brightness; 36 /* Current FB Power mode (0: full on, 1..3: power saving 37 modes; 4: full off), see FB_BLANK_XXX */ 38 int power; 39 /* FB Blanking active? (values as for power) */ 40 int fb_blank; 41 }; 42 43 struct backlight_device { 44 /* This protects the 'props' field. If 'props' is NULL, the driver that 45 registered this device has been unloaded, and if class_get_devdata() 46 points to something in the body of that driver, it is also invalid. */ 47 struct semaphore sem; 48 /* If this is NULL, the backing module is unloaded */ 49 struct backlight_properties *props; 50 /* The framebuffer notifier block */ 51 struct notifier_block fb_notif; 52 /* The class device structure */ 53 struct class_device class_dev; 54 }; 55 56 extern struct backlight_device *backlight_device_register(const char *name, 57 struct device *dev,void *devdata,struct backlight_properties *bp); 58 extern void backlight_device_unregister(struct backlight_device *bd); 59 60 #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev) 61 62 #endif 63