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linux
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#include <linux/timer.h>
19
20struct device;
21/*
22 * LED Core
23 */
24
25enum led_brightness {
26 LED_OFF = 0,
27 LED_HALF = 127,
28 LED_FULL = 255,
29};
30
31struct led_classdev {
32 const char *name;
33 int brightness;
34 int max_brightness;
35 int flags;
36
37 /* Lower 16 bits reflect status */
38#define LED_SUSPENDED (1 << 0)
39 /* Upper 16 bits reflect control information */
40#define LED_CORE_SUSPENDRESUME (1 << 16)
41
42 /* Set LED brightness level */
43 /* Must not sleep, use a workqueue if needed */
44 void (*brightness_set)(struct led_classdev *led_cdev,
45 enum led_brightness brightness);
46 /* Get LED brightness level */
47 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
48
49 /*
50 * Activate hardware accelerated blink, delays are in milliseconds
51 * and if both are zero then a sensible default should be chosen.
52 * The call should adjust the timings in that case and if it can't
53 * match the values specified exactly.
54 * Deactivate blinking again when the brightness is set to a fixed
55 * value via the brightness_set() callback.
56 */
57 int (*blink_set)(struct led_classdev *led_cdev,
58 unsigned long *delay_on,
59 unsigned long *delay_off);
60
61 struct device *dev;
62 struct list_head node; /* LED Device list */
63 const char *default_trigger; /* Trigger to use */
64
65 unsigned long blink_delay_on, blink_delay_off;
66 struct timer_list blink_timer;
67 int blink_brightness;
68
69#ifdef CONFIG_LEDS_TRIGGERS
70 /* Protects the trigger data below */
71 struct rw_semaphore trigger_lock;
72
73 struct led_trigger *trigger;
74 struct list_head trig_list;
75 void *trigger_data;
76 /* true if activated - deactivate routine uses it to do cleanup */
77 bool activated;
78#endif
79};
80
81extern int led_classdev_register(struct device *parent,
82 struct led_classdev *led_cdev);
83extern void led_classdev_unregister(struct led_classdev *led_cdev);
84extern void led_classdev_suspend(struct led_classdev *led_cdev);
85extern void led_classdev_resume(struct led_classdev *led_cdev);
86
87/**
88 * led_blink_set - set blinking with software fallback
89 * @led_cdev: the LED to start blinking
90 * @delay_on: the time it should be on (in ms)
91 * @delay_off: the time it should ble off (in ms)
92 *
93 * This function makes the LED blink, attempting to use the
94 * hardware acceleration if possible, but falling back to
95 * software blinking if there is no hardware blinking or if
96 * the LED refuses the passed values.
97 *
98 * Note that if software blinking is active, simply calling
99 * led_cdev->brightness_set() will not stop the blinking,
100 * use led_classdev_brightness_set() instead.
101 */
102extern void led_blink_set(struct led_classdev *led_cdev,
103 unsigned long *delay_on,
104 unsigned long *delay_off);
105/**
106 * led_brightness_set - set LED brightness
107 * @led_cdev: the LED to set
108 * @brightness: the brightness to set it to
109 *
110 * Set an LED's brightness, and, if necessary, cancel the
111 * software blink timer that implements blinking when the
112 * hardware doesn't.
113 */
114extern void led_brightness_set(struct led_classdev *led_cdev,
115 enum led_brightness brightness);
116
117/*
118 * LED Triggers
119 */
120#ifdef CONFIG_LEDS_TRIGGERS
121
122#define TRIG_NAME_MAX 50
123
124struct led_trigger {
125 /* Trigger Properties */
126 const char *name;
127 void (*activate)(struct led_classdev *led_cdev);
128 void (*deactivate)(struct led_classdev *led_cdev);
129
130 /* LEDs under control by this trigger (for simple triggers) */
131 rwlock_t leddev_list_lock;
132 struct list_head led_cdevs;
133
134 /* Link to next registered trigger */
135 struct list_head next_trig;
136};
137
138/* Registration functions for complex triggers */
139extern int led_trigger_register(struct led_trigger *trigger);
140extern void led_trigger_unregister(struct led_trigger *trigger);
141
142/* Registration functions for simple triggers */
143#define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
144#define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
145extern void led_trigger_register_simple(const char *name,
146 struct led_trigger **trigger);
147extern void led_trigger_unregister_simple(struct led_trigger *trigger);
148extern void led_trigger_event(struct led_trigger *trigger,
149 enum led_brightness event);
150extern void led_trigger_blink(struct led_trigger *trigger,
151 unsigned long *delay_on,
152 unsigned long *delay_off);
153
154#else
155
156/* Triggers aren't active - null macros */
157#define DEFINE_LED_TRIGGER(x)
158#define DEFINE_LED_TRIGGER_GLOBAL(x)
159#define led_trigger_register_simple(x, y) do {} while(0)
160#define led_trigger_unregister_simple(x) do {} while(0)
161#define led_trigger_event(x, y) do {} while(0)
162
163#endif
164
165/* Trigger specific functions */
166#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
167extern void ledtrig_ide_activity(void);
168#else
169#define ledtrig_ide_activity() do {} while(0)
170#endif
171
172/*
173 * Generic LED platform data for describing LED names and default triggers.
174 */
175struct led_info {
176 const char *name;
177 const char *default_trigger;
178 int flags;
179};
180
181struct led_platform_data {
182 int num_leds;
183 struct led_info *leds;
184};
185
186/* For the leds-gpio driver */
187struct gpio_led {
188 const char *name;
189 const char *default_trigger;
190 unsigned gpio;
191 unsigned active_low : 1;
192 unsigned retain_state_suspended : 1;
193 unsigned default_state : 2;
194 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
195};
196#define LEDS_GPIO_DEFSTATE_OFF 0
197#define LEDS_GPIO_DEFSTATE_ON 1
198#define LEDS_GPIO_DEFSTATE_KEEP 2
199
200struct gpio_led_platform_data {
201 int num_leds;
202 const struct gpio_led *leds;
203
204#define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
205#define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
206#define GPIO_LED_BLINK 2 /* Please, blink */
207 int (*gpio_blink_set)(unsigned gpio, int state,
208 unsigned long *delay_on,
209 unsigned long *delay_off);
210};
211
212struct platform_device *gpio_led_register_device(
213 int id, const struct gpio_led_platform_data *pdata);
214
215#endif /* __LINUX_LEDS_H_INCLUDED */