/* * 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/mutex.h> #include <linux/notifier.h> /* Notes on locking: * * backlight_device->ops_lock is an internal backlight lock protecting the * ops pointer and no code outside the core should need to touch it. * * Access to update_status() is serialised by the update_lock mutex since * most drivers seem to need this and historically get it wrong. * * Most drivers don't need locking on their get_brightness() method. * If yours does, you need to implement it in the driver. You can use the * update_lock mutex if appropriate. * * Any other use of the locks below is probably wrong. */ struct backlight_device; struct fb_info; struct backlight_ops { /* Notify the backlight driver some property has changed */ int (*update_status)(struct backlight_device *); /* Return the current backlight brightness (accounting for power, fb_blank etc.) */ int (*get_brightness)(struct backlight_device *); /* 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 *); }; /* This structure defines all the properties of a backlight */ struct backlight_properties { /* Current User requested brightness (0 - max_brightness) */ int brightness; /* Maximal value for brightness (read-only) */ int max_brightness; /* Current FB Power mode (0: full on, 1..3: power saving modes; 4: full off), see FB_BLANK_XXX */ int power; /* FB Blanking active? (values as for power) */ int fb_blank; }; struct backlight_device { /* Backlight properties */ struct backlight_properties props; /* Serialise access to update_status method */ struct mutex update_lock; /* This protects the 'ops' field. If 'ops' 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 mutex ops_lock; struct backlight_ops *ops; /* The framebuffer notifier block */ struct notifier_block fb_notif; struct device dev; }; static inline void backlight_update_status(struct backlight_device *bd) { mutex_lock(&bd->update_lock); if (bd->ops && bd->ops->update_status) bd->ops->update_status(bd); mutex_unlock(&bd->update_lock); } extern struct backlight_device *backlight_device_register(const char *name, struct device *dev, void *devdata, struct backlight_ops *ops); extern void backlight_device_unregister(struct backlight_device *bd); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) static inline void * bl_get_data(struct backlight_device *bl_dev) { return dev_get_drvdata(&bl_dev->dev); } struct generic_bl_info { const char *name; int max_intensity; int default_intensity; int limit_mask; void (*set_bl_intensity)(int intensity); void (*kick_battery)(void); }; #endif