Subversion Repositories test_project

/*

 * 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