128 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Backlight Lowlevel Control Abstraction
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 *
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 * Copyright (C) 2003,2004 Hewlett-Packard Company
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 *
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 */
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#ifndef _LINUX_BACKLIGHT_H
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#define _LINUX_BACKLIGHT_H
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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/* Notes on locking:
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 *
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 * backlight_device->ops_lock is an internal backlight lock protecting the
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 * ops pointer and no code outside the core should need to touch it.
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 *
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 * Access to update_status() is serialised by the update_lock mutex since
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 * most drivers seem to need this and historically get it wrong.
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 *
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 * Most drivers don't need locking on their get_brightness() method.
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 * If yours does, you need to implement it in the driver. You can use the
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 * update_lock mutex if appropriate.
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 *
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 * Any other use of the locks below is probably wrong.
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 */
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enum backlight_update_reason {
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	BACKLIGHT_UPDATE_HOTKEY,
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	BACKLIGHT_UPDATE_SYSFS,
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};
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struct backlight_device;
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struct fb_info;
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struct backlight_ops {
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	unsigned int options;
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#define BL_CORE_SUSPENDRESUME	(1 << 0)
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	/* Notify the backlight driver some property has changed */
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	int (*update_status)(struct backlight_device *);
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	/* Return the current backlight brightness (accounting for power,
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	   fb_blank etc.) */
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	int (*get_brightness)(struct backlight_device *);
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	/* Check if given framebuffer device is the one bound to this backlight;
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	   return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
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	int (*check_fb)(struct fb_info *);
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};
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/* This structure defines all the properties of a backlight */
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struct backlight_properties {
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	/* Current User requested brightness (0 - max_brightness) */
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	int brightness;
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	/* Maximal value for brightness (read-only) */
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	int max_brightness;
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	/* Current FB Power mode (0: full on, 1..3: power saving
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	   modes; 4: full off), see FB_BLANK_XXX */
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	int power;
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	/* FB Blanking active? (values as for power) */
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	/* Due to be removed, please use (state & BL_CORE_FBBLANK) */
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	int fb_blank;
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	/* Flags used to signal drivers of state changes */
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	/* Upper 4 bits are reserved for driver internal use */
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	unsigned int state;
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#define BL_CORE_SUSPENDED	(1 << 0)	/* backlight is suspended */
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#define BL_CORE_FBBLANK		(1 << 1)	/* backlight is under an fb blank event */
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#define BL_CORE_DRIVER4		(1 << 28)	/* reserved for driver specific use */
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#define BL_CORE_DRIVER3		(1 << 29)	/* reserved for driver specific use */
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#define BL_CORE_DRIVER2		(1 << 30)	/* reserved for driver specific use */
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#define BL_CORE_DRIVER1		(1 << 31)	/* reserved for driver specific use */
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};
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struct backlight_device {
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	/* Backlight properties */
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	struct backlight_properties props;
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	/* Serialise access to update_status method */
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	struct mutex update_lock;
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	/* This protects the 'ops' field. If 'ops' is NULL, the driver that
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	   registered this device has been unloaded, and if class_get_devdata()
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	   points to something in the body of that driver, it is also invalid. */
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	struct mutex ops_lock;
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	struct backlight_ops *ops;
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	/* The framebuffer notifier block */
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	struct notifier_block fb_notif;
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	struct device dev;
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};
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static inline void backlight_update_status(struct backlight_device *bd)
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{
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	mutex_lock(&bd->update_lock);
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	if (bd->ops && bd->ops->update_status)
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		bd->ops->update_status(bd);
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	mutex_unlock(&bd->update_lock);
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}
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extern struct backlight_device *backlight_device_register(const char *name,
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	struct device *dev, void *devdata, struct backlight_ops *ops);
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extern void backlight_device_unregister(struct backlight_device *bd);
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extern void backlight_force_update(struct backlight_device *bd,
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				   enum backlight_update_reason reason);
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#define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
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static inline void * bl_get_data(struct backlight_device *bl_dev)
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{
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	return dev_get_drvdata(&bl_dev->dev);
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}
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struct generic_bl_info {
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	const char *name;
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	int max_intensity;
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	int default_intensity;
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	int limit_mask;
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	void (*set_bl_intensity)(int intensity);
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	void (*kick_battery)(void);
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};
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#endif
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