leds: Document the context brightness_set needs
[linux-2.6.git] / include / linux / leds.h
1 /*
2  * Driver model for leds and led triggers
3  *
4  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5  * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12 #ifndef __LINUX_LEDS_H_INCLUDED
13 #define __LINUX_LEDS_H_INCLUDED
14
15 #include <linux/list.h>
16 #include <linux/spinlock.h>
17 #include <linux/rwsem.h>
18
19 struct device;
20 /*
21  * LED Core
22  */
23
24 enum led_brightness {
25         LED_OFF         = 0,
26         LED_HALF        = 127,
27         LED_FULL        = 255,
28 };
29
30 struct led_classdev {
31         const char              *name;
32         int                      brightness;
33         int                      flags;
34
35 #define LED_SUSPENDED           (1 << 0)
36
37         /* Set LED brightness level */
38         /* Must not sleep, use a workqueue if needed */
39         void            (*brightness_set)(struct led_classdev *led_cdev,
40                                           enum led_brightness brightness);
41         /* Get LED brightness level */
42         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
43
44         /* Activate hardware accelerated blink */
45         int             (*blink_set)(struct led_classdev *led_cdev,
46                                      unsigned long *delay_on,
47                                      unsigned long *delay_off);
48
49         struct device           *dev;
50         struct list_head         node;                  /* LED Device list */
51         char                    *default_trigger;       /* Trigger to use */
52
53 #ifdef CONFIG_LEDS_TRIGGERS
54         /* Protects the trigger data below */
55         struct rw_semaphore      trigger_lock;
56
57         struct led_trigger      *trigger;
58         struct list_head         trig_list;
59         void                    *trigger_data;
60 #endif
61 };
62
63 extern int led_classdev_register(struct device *parent,
64                                  struct led_classdev *led_cdev);
65 extern void led_classdev_unregister(struct led_classdev *lcd);
66 extern void led_classdev_suspend(struct led_classdev *led_cdev);
67 extern void led_classdev_resume(struct led_classdev *led_cdev);
68
69 /*
70  * LED Triggers
71  */
72 #ifdef CONFIG_LEDS_TRIGGERS
73
74 #define TRIG_NAME_MAX 50
75
76 struct led_trigger {
77         /* Trigger Properties */
78         const char       *name;
79         void            (*activate)(struct led_classdev *led_cdev);
80         void            (*deactivate)(struct led_classdev *led_cdev);
81
82         /* LEDs under control by this trigger (for simple triggers) */
83         rwlock_t          leddev_list_lock;
84         struct list_head  led_cdevs;
85
86         /* Link to next registered trigger */
87         struct list_head  next_trig;
88 };
89
90 /* Registration functions for complex triggers */
91 extern int led_trigger_register(struct led_trigger *trigger);
92 extern void led_trigger_unregister(struct led_trigger *trigger);
93
94 /* Registration functions for simple triggers */
95 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
96 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
97 extern void led_trigger_register_simple(const char *name,
98                                 struct led_trigger **trigger);
99 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
100 extern void led_trigger_event(struct led_trigger *trigger,
101                                 enum led_brightness event);
102
103 #else
104
105 /* Triggers aren't active - null macros */
106 #define DEFINE_LED_TRIGGER(x)
107 #define DEFINE_LED_TRIGGER_GLOBAL(x)
108 #define led_trigger_register_simple(x, y) do {} while(0)
109 #define led_trigger_unregister_simple(x) do {} while(0)
110 #define led_trigger_event(x, y) do {} while(0)
111
112 #endif
113
114 /* Trigger specific functions */
115 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
116 extern void ledtrig_ide_activity(void);
117 #else
118 #define ledtrig_ide_activity() do {} while(0)
119 #endif
120
121 /* For the leds-gpio driver */
122 struct gpio_led {
123         const char *name;
124         char *default_trigger;
125         unsigned        gpio;
126         u8              active_low;
127 };
128
129 struct gpio_led_platform_data {
130         int             num_leds;
131         struct gpio_led *leds;
132         int             (*gpio_blink_set)(unsigned gpio,
133                                         unsigned long *delay_on,
134                                         unsigned long *delay_off);
135 };
136
137
138 #endif          /* __LINUX_LEDS_H_INCLUDED */