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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>
Liu Yinga55944c2014-04-03 14:48:54 -070012#include <linux/fb.h>
Richard Purdie28ee0862007-02-08 22:25:09 +000013#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/notifier.h>
15
Richard Purdie28ee0862007-02-08 22:25:09 +000016/* Notes on locking:
17 *
Richard Purdie599a52d2007-02-10 23:07:48 +000018 * backlight_device->ops_lock is an internal backlight lock protecting the
19 * ops pointer and no code outside the core should need to touch it.
Richard Purdie28ee0862007-02-08 22:25:09 +000020 *
21 * Access to update_status() is serialised by the update_lock mutex since
22 * most drivers seem to need this and historically get it wrong.
23 *
24 * Most drivers don't need locking on their get_brightness() method.
25 * If yours does, you need to implement it in the driver. You can use the
26 * update_lock mutex if appropriate.
27 *
28 * Any other use of the locks below is probably wrong.
29 */
30
Matthew Garrett325253a2009-07-14 17:06:02 +010031enum backlight_update_reason {
32 BACKLIGHT_UPDATE_HOTKEY,
33 BACKLIGHT_UPDATE_SYSFS,
34};
35
Matthew Garrettbb7ca742011-03-22 16:30:21 -070036enum backlight_type {
37 BACKLIGHT_RAW = 1,
38 BACKLIGHT_PLATFORM,
39 BACKLIGHT_FIRMWARE,
40 BACKLIGHT_TYPE_MAX,
41};
42
Hans de Goede3cc69192014-05-21 15:39:54 +020043enum backlight_notification {
44 BACKLIGHT_REGISTERED,
45 BACKLIGHT_UNREGISTERED,
46};
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048struct backlight_device;
49struct fb_info;
50
Richard Purdie599a52d2007-02-10 23:07:48 +000051struct backlight_ops {
Richard Purdieb4144e42010-01-18 14:16:07 +000052 unsigned int options;
Richard Purdiec835ee72009-01-06 21:00:19 +000053
54#define BL_CORE_SUSPENDRESUME (1 << 0)
55
Richard Purdie6ca01762006-03-31 02:31:49 -080056 /* Notify the backlight driver some property has changed */
Richard Purdieb4144e42010-01-18 14:16:07 +000057 int (*update_status)(struct backlight_device *);
Richard Purdie6ca01762006-03-31 02:31:49 -080058 /* Return the current backlight brightness (accounting for power,
59 fb_blank etc.) */
Richard Purdieb4144e42010-01-18 14:16:07 +000060 int (*get_brightness)(struct backlight_device *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 /* Check if given framebuffer device is the one bound to this backlight;
62 return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
Bruno Prémont57e148b2010-02-21 00:20:01 +010063 int (*check_fb)(struct backlight_device *, struct fb_info *);
Richard Purdie599a52d2007-02-10 23:07:48 +000064};
Richard Purdie6ca01762006-03-31 02:31:49 -080065
Richard Purdie599a52d2007-02-10 23:07:48 +000066/* This structure defines all the properties of a backlight */
67struct backlight_properties {
Richard Purdie6ca01762006-03-31 02:31:49 -080068 /* Current User requested brightness (0 - max_brightness) */
69 int brightness;
70 /* Maximal value for brightness (read-only) */
71 int max_brightness;
72 /* Current FB Power mode (0: full on, 1..3: power saving
73 modes; 4: full off), see FB_BLANK_XXX */
74 int power;
75 /* FB Blanking active? (values as for power) */
Richard Purdiec835ee72009-01-06 21:00:19 +000076 /* Due to be removed, please use (state & BL_CORE_FBBLANK) */
Richard Purdie6ca01762006-03-31 02:31:49 -080077 int fb_blank;
Matthew Garrettbb7ca742011-03-22 16:30:21 -070078 /* Backlight type */
79 enum backlight_type type;
Richard Purdiec835ee72009-01-06 21:00:19 +000080 /* Flags used to signal drivers of state changes */
81 /* Upper 4 bits are reserved for driver internal use */
82 unsigned int state;
83
84#define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */
85#define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */
86#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver specific use */
87#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver specific use */
88#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver specific use */
89#define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver specific use */
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091};
92
93struct backlight_device {
Richard Purdie599a52d2007-02-10 23:07:48 +000094 /* Backlight properties */
95 struct backlight_properties props;
96
Richard Purdie28ee0862007-02-08 22:25:09 +000097 /* Serialise access to update_status method */
98 struct mutex update_lock;
Richard Purdie599a52d2007-02-10 23:07:48 +000099
100 /* This protects the 'ops' field. If 'ops' is NULL, the driver that
101 registered this device has been unloaded, and if class_get_devdata()
102 points to something in the body of that driver, it is also invalid. */
103 struct mutex ops_lock;
Emese Revfy9905a432009-12-14 00:58:57 +0100104 const struct backlight_ops *ops;
Richard Purdie599a52d2007-02-10 23:07:48 +0000105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 /* The framebuffer notifier block */
107 struct notifier_block fb_notif;
Richard Purdie655bfd72007-07-09 12:17:24 +0100108
Aaron Lu5915a3d2013-10-11 21:27:43 +0800109 /* list entry of all registered backlight devices */
110 struct list_head entry;
111
Richard Purdie655bfd72007-07-09 12:17:24 +0100112 struct device dev;
Liu Yinga55944c2014-04-03 14:48:54 -0700113
114 /* Multiple framebuffers may share one backlight device */
115 bool fb_bl_on[FB_MAX];
116
117 int use_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118};
119
Hyungwon Hwangcca0ba22015-05-28 16:25:15 +0900120static inline int backlight_update_status(struct backlight_device *bd)
Richard Purdie28ee0862007-02-08 22:25:09 +0000121{
Hyungwon Hwangcca0ba22015-05-28 16:25:15 +0900122 int ret = -ENOENT;
123
Richard Purdie28ee0862007-02-08 22:25:09 +0000124 mutex_lock(&bd->update_lock);
Richard Purdie599a52d2007-02-10 23:07:48 +0000125 if (bd->ops && bd->ops->update_status)
Hyungwon Hwangcca0ba22015-05-28 16:25:15 +0900126 ret = bd->ops->update_status(bd);
Richard Purdie28ee0862007-02-08 22:25:09 +0000127 mutex_unlock(&bd->update_lock);
Hyungwon Hwangcca0ba22015-05-28 16:25:15 +0900128
129 return ret;
Richard Purdie28ee0862007-02-08 22:25:09 +0000130}
131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132extern struct backlight_device *backlight_device_register(const char *name,
Matthew Garretta19a6ee2010-02-17 16:39:44 -0500133 struct device *dev, void *devdata, const struct backlight_ops *ops,
134 const struct backlight_properties *props);
Jingoo Han8318fde42013-07-03 15:05:13 -0700135extern struct backlight_device *devm_backlight_device_register(
136 struct device *dev, const char *name, struct device *parent,
137 void *devdata, const struct backlight_ops *ops,
138 const struct backlight_properties *props);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139extern void backlight_device_unregister(struct backlight_device *bd);
Jingoo Han8318fde42013-07-03 15:05:13 -0700140extern void devm_backlight_device_unregister(struct device *dev,
141 struct backlight_device *bd);
Matthew Garrett325253a2009-07-14 17:06:02 +0100142extern void backlight_force_update(struct backlight_device *bd,
143 enum backlight_update_reason reason);
Hans de Goede3cc69192014-05-21 15:39:54 +0200144extern int backlight_register_notifier(struct notifier_block *nb);
145extern int backlight_unregister_notifier(struct notifier_block *nb);
Aaron Luf6a47902016-04-27 20:45:02 +0800146extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
147extern int backlight_device_set_brightness(struct backlight_device *bd, unsigned long brightness);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Richard Purdie655bfd72007-07-09 12:17:24 +0100149#define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
150
151static inline void * bl_get_data(struct backlight_device *bl_dev)
152{
153 return dev_get_drvdata(&bl_dev->dev);
154}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Richard Purdiec3f8f652007-09-03 00:27:00 +0100156struct generic_bl_info {
157 const char *name;
158 int max_intensity;
159 int default_intensity;
160 int limit_mask;
161 void (*set_bl_intensity)(int intensity);
162 void (*kick_battery)(void);
163};
164
Thierry Reding762a9362012-12-17 16:01:06 -0800165#ifdef CONFIG_OF
166struct backlight_device *of_find_backlight_by_node(struct device_node *node);
167#else
168static inline struct backlight_device *
169of_find_backlight_by_node(struct device_node *node)
170{
171 return NULL;
172}
173#endif
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175#endif