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 /* Get the backlight power status (0: full on, 1..3: power saving 23 modes; 4: full off), see FB_BLANK_XXX */ 24 int (*get_power)(struct backlight_device *); 25 /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ 26 int (*set_power)(struct backlight_device *, int power); 27 /* Maximal value for brightness (read-only) */ 28 int max_brightness; 29 /* Get current backlight brightness */ 30 int (*get_brightness)(struct backlight_device *); 31 /* Set backlight brightness (0..max_brightness) */ 32 int (*set_brightness)(struct backlight_device *, int brightness); 33 /* Check if given framebuffer device is the one bound to this backlight; 34 return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */ 35 int (*check_fb)(struct fb_info *); 36 }; 37 38 struct backlight_device { 39 /* This protects the 'props' field. If 'props' is NULL, the driver that 40 registered this device has been unloaded, and if class_get_devdata() 41 points to something in the body of that driver, it is also invalid. */ 42 struct semaphore sem; 43 /* If this is NULL, the backing module is unloaded */ 44 struct backlight_properties *props; 45 /* The framebuffer notifier block */ 46 struct notifier_block fb_notif; 47 /* The class device structure */ 48 struct class_device class_dev; 49 }; 50 51 extern struct backlight_device *backlight_device_register(const char *name, 52 void *devdata, struct backlight_properties *bp); 53 extern void backlight_device_unregister(struct backlight_device *bd); 54 55 #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev) 56 57 #endif 58