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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Backlight Lowlevel Control Abstraction
3 *
4 * Copyright (C) 2003,2004 Hewlett-Packard Company
5 *
6 */
7
8#ifndef _LINUX_BACKLIGHT_H
9#define _LINUX_BACKLIGHT_H
10
11#include <linux/device.h>
Richard Purdie28ee0862007-02-08 22:25:09 +000012#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/notifier.h>
14
Richard Purdie28ee0862007-02-08 22:25:09 +000015/* Notes on locking:
16 *
Richard Purdie599a52d2007-02-10 23:07:48 +000017 * backlight_device->ops_lock is an internal backlight lock protecting the
18 * ops pointer and no code outside the core should need to touch it.
Richard Purdie28ee0862007-02-08 22:25:09 +000019 *
20 * Access to update_status() is serialised by the update_lock mutex since
21 * most drivers seem to need this and historically get it wrong.
22 *
23 * Most drivers don't need locking on their get_brightness() method.
24 * If yours does, you need to implement it in the driver. You can use the
25 * update_lock mutex if appropriate.
26 *
27 * Any other use of the locks below is probably wrong.
28 */
29
Matthew Garrett325253a2009-07-14 17:06:02 +010030enum backlight_update_reason {
31 BACKLIGHT_UPDATE_HOTKEY,
32 BACKLIGHT_UPDATE_SYSFS,
33};
34
Matthew Garrettbb7ca742011-03-22 16:30:21 -070035enum backlight_type {
36 BACKLIGHT_RAW = 1,
37 BACKLIGHT_PLATFORM,
38 BACKLIGHT_FIRMWARE,
39 BACKLIGHT_TYPE_MAX,
40};
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042struct backlight_device;
43struct fb_info;
44
Richard Purdie599a52d2007-02-10 23:07:48 +000045struct backlight_ops {
Richard Purdieb4144e42010-01-18 14:16:07 +000046 unsigned int options;
Richard Purdiec835ee72009-01-06 21:00:19 +000047
48#define BL_CORE_SUSPENDRESUME (1 << 0)
49
Richard Purdie6ca01762006-03-31 02:31:49 -080050 /* Notify the backlight driver some property has changed */
Richard Purdieb4144e42010-01-18 14:16:07 +000051 int (*update_status)(struct backlight_device *);
Richard Purdie6ca01762006-03-31 02:31:49 -080052 /* Return the current backlight brightness (accounting for power,
53 fb_blank etc.) */
Richard Purdieb4144e42010-01-18 14:16:07 +000054 int (*get_brightness)(struct backlight_device *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 /* Check if given framebuffer device is the one bound to this backlight;
56 return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
Bruno Prémont57e148b2010-02-21 00:20:01 +010057 int (*check_fb)(struct backlight_device *, struct fb_info *);
Richard Purdie599a52d2007-02-10 23:07:48 +000058};
Richard Purdie6ca01762006-03-31 02:31:49 -080059
Richard Purdie599a52d2007-02-10 23:07:48 +000060/* This structure defines all the properties of a backlight */
61struct backlight_properties {
Richard Purdie6ca01762006-03-31 02:31:49 -080062 /* Current User requested brightness (0 - max_brightness) */
63 int brightness;
64 /* Maximal value for brightness (read-only) */
65 int max_brightness;
66 /* Current FB Power mode (0: full on, 1..3: power saving
67 modes; 4: full off), see FB_BLANK_XXX */
68 int power;
69 /* FB Blanking active? (values as for power) */
Richard Purdiec835ee72009-01-06 21:00:19 +000070 /* Due to be removed, please use (state & BL_CORE_FBBLANK) */
Richard Purdie6ca01762006-03-31 02:31:49 -080071 int fb_blank;
Matthew Garrettbb7ca742011-03-22 16:30:21 -070072 /* Backlight type */
73 enum backlight_type type;
Richard Purdiec835ee72009-01-06 21:00:19 +000074 /* Flags used to signal drivers of state changes */
75 /* Upper 4 bits are reserved for driver internal use */
76 unsigned int state;
77
78#define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
79#define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
80#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver specific use */
81#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver specific use */
82#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver specific use */
83#define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver specific use */
84
Linus Torvalds1da177e2005-04-16 15:20:36 -070085};
86
87struct backlight_device {
Richard Purdie599a52d2007-02-10 23:07:48 +000088 /* Backlight properties */
89 struct backlight_properties props;
90
Richard Purdie28ee0862007-02-08 22:25:09 +000091 /* Serialise access to update_status method */
92 struct mutex update_lock;
Richard Purdie599a52d2007-02-10 23:07:48 +000093
94 /* This protects the 'ops' field. If 'ops' is NULL, the driver that
95 registered this device has been unloaded, and if class_get_devdata()
96 points to something in the body of that driver, it is also invalid. */
97 struct mutex ops_lock;
Emese Revfy9905a432009-12-14 00:58:57 +010098 const struct backlight_ops *ops;
Richard Purdie599a52d2007-02-10 23:07:48 +000099
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 /* The framebuffer notifier block */
101 struct notifier_block fb_notif;
Richard Purdie655bfd72007-07-09 12:17:24 +0100102
103 struct device dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104};
105
Richard Purdie28ee0862007-02-08 22:25:09 +0000106static inline void backlight_update_status(struct backlight_device *bd)
107{
108 mutex_lock(&bd->update_lock);
Richard Purdie599a52d2007-02-10 23:07:48 +0000109 if (bd->ops && bd->ops->update_status)
110 bd->ops->update_status(bd);
Richard Purdie28ee0862007-02-08 22:25:09 +0000111 mutex_unlock(&bd->update_lock);
112}
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114extern struct backlight_device *backlight_device_register(const char *name,
Matthew Garretta19a6ee2010-02-17 16:39:44 -0500115 struct device *dev, void *devdata, const struct backlight_ops *ops,
116 const struct backlight_properties *props);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117extern void backlight_device_unregister(struct backlight_device *bd);
Matthew Garrett325253a2009-07-14 17:06:02 +0100118extern void backlight_force_update(struct backlight_device *bd,
119 enum backlight_update_reason reason);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Richard Purdie655bfd72007-07-09 12:17:24 +0100121#define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
122
123static inline void * bl_get_data(struct backlight_device *bl_dev)
124{
125 return dev_get_drvdata(&bl_dev->dev);
126}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
Richard Purdiec3f8f652007-09-03 00:27:00 +0100128struct generic_bl_info {
129 const char *name;
130 int max_intensity;
131 int default_intensity;
132 int limit_mask;
133 void (*set_bl_intensity)(int intensity);
134 void (*kick_battery)(void);
135};
136
Thierry Reding762a9362012-12-17 16:01:06 -0800137#ifdef CONFIG_OF
138struct backlight_device *of_find_backlight_by_node(struct device_node *node);
139#else
140static inline struct backlight_device *
141of_find_backlight_by_node(struct device_node *node)
142{
143 return NULL;
144}
145#endif
146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147#endif