/*
* 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.
*/
enum backlight_update_reason {
BACKLIGHT_UPDATE_HOTKEY,
BACKLIGHT_UPDATE_SYSFS,
};
struct backlight_device;
struct fb_info;
struct backlight_ops {
const unsigned int options;
#define BL_CORE_SUSPENDRESUME (1 << 0)
/* Notify the backlight driver some property has changed */
int (* const update_status)(struct backlight_device *);
/* Return the current backlight brightness (accounting for power,
fb_blank etc.) */
int (* const 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 (* const 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) */
/* Due to be removed, please use (state & BL_CORE_FBBLANK) */
int fb_blank;
/* Flags used to signal drivers of state changes */
/* Upper 4 bits are reserved for driver internal use */
unsigned int state;
#define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
#define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver specific use */
#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver specific use */
#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver specific use */
#define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver specific use */
};
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;
const 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, const struct backlight_ops *ops);
extern void backlight_device_unregister(struct backlight_device *bd);
extern void backlight_force_update(struct backlight_device *bd,
enum backlight_update_reason reason);
#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
