/* * Backlight Lowlevel Control Abstraction * * Copyright (C) 2003,2004 Hewlett-Packard Company * */ #ifndef _LINUX_BACKLIGHT_H #define _LINUX_BACKLIGHT_H #include <linux/device.h> #include <linux/notifier.h> struct backlight_device; struct fb_info; /* This structure defines all the properties of a backlight (usually attached to a LCD). */ struct backlight_properties { /* Owner module */ struct module *owner; /* Get the backlight power status (0: full on, 1..3: power saving modes; 4: full off), see FB_BLANK_XXX */ int (*get_power)(struct backlight_device *); /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ int (*set_power)(struct backlight_device *, int power); /* Maximal value for brightness (read-only) */ int max_brightness; /* Get current backlight brightness */ int (*get_brightness)(struct backlight_device *); /* Set backlight brightness (0..max_brightness) */ int (*set_brightness)(struct backlight_device *, int brightness); /* Check if given framebuffer device is the one bound to this backlight; return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */ int (*check_fb)(struct fb_info *); }; struct backlight_device { /* This protects the 'props' field. If 'props' is NULL, the driver that registered this device has been unloaded, and if class_get_devdata() points to something in the body of that driver, it is also invalid. */ struct semaphore sem; /* If this is NULL, the backing module is unloaded */ struct backlight_properties *props; /* The framebuffer notifier block */ struct notifier_block fb_notif; /* The class device structure */ struct class_device class_dev; }; extern struct backlight_device *backlight_device_register(const char *name, void *devdata, struct backlight_properties *bp); extern void backlight_device_unregister(struct backlight_device *bd); #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev) #endif