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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/workqueue.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#define LED_BLINK_ONESHOT (1 << 17)
42#define LED_BLINK_ONESHOT_STOP (1 << 18)
43#define LED_BLINK_INVERT (1 << 19)
44
45 /* Set LED brightness level */
46 /* Must not sleep, use a workqueue if needed */
47 void (*brightness_set)(struct led_classdev *led_cdev,
48 enum led_brightness brightness);
49 /* Get LED brightness level */
50 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
51
52 /*
53 * Activate hardware accelerated blink, delays are in milliseconds
54 * and if both are zero then a sensible default should be chosen.
55 * The call should adjust the timings in that case and if it can't
56 * match the values specified exactly.
57 * Deactivate blinking again when the brightness is set to a fixed
58 * value via the brightness_set() callback.
59 */
60 int (*blink_set)(struct led_classdev *led_cdev,
61 unsigned long *delay_on,
62 unsigned long *delay_off);
63
64 struct device *dev;
65 const struct attribute_group **groups;
66
67 struct list_head node; /* LED Device list */
68 const char *default_trigger; /* Trigger to use */
69
70 unsigned long blink_delay_on, blink_delay_off;
71 struct delayed_work blink_work;
72 int blink_brightness;
73
74 struct work_struct set_brightness_work;
75 int delayed_set_value;
76
77#ifdef CONFIG_LEDS_TRIGGERS
78 /* Protects the trigger data below */
79 struct rw_semaphore trigger_lock;
80
81 struct led_trigger *trigger;
82 struct list_head trig_list;
83 void *trigger_data;
84 /* true if activated - deactivate routine uses it to do cleanup */
85 bool activated;
86#endif
87};
88
89extern int led_classdev_register(struct device *parent,
90 struct led_classdev *led_cdev);
91extern void led_classdev_unregister(struct led_classdev *led_cdev);
92extern void led_classdev_suspend(struct led_classdev *led_cdev);
93extern void led_classdev_resume(struct led_classdev *led_cdev);
94
95/**
96 * led_blink_set - set blinking with software fallback
97 * @led_cdev: the LED to start blinking
98 * @delay_on: the time it should be on (in ms)
99 * @delay_off: the time it should ble off (in ms)
100 *
101 * This function makes the LED blink, attempting to use the
102 * hardware acceleration if possible, but falling back to
103 * software blinking if there is no hardware blinking or if
104 * the LED refuses the passed values.
105 *
106 * Note that if software blinking is active, simply calling
107 * led_cdev->brightness_set() will not stop the blinking,
108 * use led_classdev_brightness_set() instead.
109 */
110extern void led_blink_set(struct led_classdev *led_cdev,
111 unsigned long *delay_on,
112 unsigned long *delay_off);
113/**
114 * led_blink_set_oneshot - do a oneshot software blink
115 * @led_cdev: the LED to start blinking
116 * @delay_on: the time it should be on (in ms)
117 * @delay_off: the time it should ble off (in ms)
118 * @invert: blink off, then on, leaving the led on
119 *
120 * This function makes the LED blink one time for delay_on +
121 * delay_off time, ignoring the request if another one-shot
122 * blink is already in progress.
123 *
124 * If invert is set, led blinks for delay_off first, then for
125 * delay_on and leave the led on after the on-off cycle.
126 */
127extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
128 unsigned long *delay_on,
129 unsigned long *delay_off,
130 int invert);
131/**
132 * led_set_brightness - set LED brightness
133 * @led_cdev: the LED to set
134 * @brightness: the brightness to set it to
135 *
136 * Set an LED's brightness, and, if necessary, cancel the
137 * software blink timer that implements blinking when the
138 * hardware doesn't.
139 */
140extern void led_set_brightness(struct led_classdev *led_cdev,
141 enum led_brightness brightness);
142
143/*
144 * LED Triggers
145 */
146/* Registration functions for simple triggers */
147#define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
148#define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
149
150#ifdef CONFIG_LEDS_TRIGGERS
151
152#define TRIG_NAME_MAX 50
153
154struct led_trigger {
155 /* Trigger Properties */
156 const char *name;
157 void (*activate)(struct led_classdev *led_cdev);
158 void (*deactivate)(struct led_classdev *led_cdev);
159
160 /* LEDs under control by this trigger (for simple triggers) */
161 rwlock_t leddev_list_lock;
162 struct list_head led_cdevs;
163
164 /* Link to next registered trigger */
165 struct list_head next_trig;
166};
167
168/* Registration functions for complex triggers */
169extern int led_trigger_register(struct led_trigger *trigger);
170extern void led_trigger_unregister(struct led_trigger *trigger);
171
172extern void led_trigger_register_simple(const char *name,
173 struct led_trigger **trigger);
174extern void led_trigger_unregister_simple(struct led_trigger *trigger);
175extern void led_trigger_event(struct led_trigger *trigger,
176 enum led_brightness event);
177extern void led_trigger_blink(struct led_trigger *trigger,
178 unsigned long *delay_on,
179 unsigned long *delay_off);
180extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
181 unsigned long *delay_on,
182 unsigned long *delay_off,
183 int invert);
184/**
185 * led_trigger_rename_static - rename a trigger
186 * @name: the new trigger name
187 * @trig: the LED trigger to rename
188 *
189 * Change a LED trigger name by copying the string passed in
190 * name into current trigger name, which MUST be large
191 * enough for the new string.
192 *
193 * Note that name must NOT point to the same string used
194 * during LED registration, as that could lead to races.
195 *
196 * This is meant to be used on triggers with statically
197 * allocated name.
198 */
199extern void led_trigger_rename_static(const char *name,
200 struct led_trigger *trig);
201
202#else
203
204/* Trigger has no members */
205struct led_trigger {};
206
207/* Trigger inline empty functions */
208static inline void led_trigger_register_simple(const char *name,
209 struct led_trigger **trigger) {}
210static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
211static inline void led_trigger_event(struct led_trigger *trigger,
212 enum led_brightness event) {}
213#endif /* CONFIG_LEDS_TRIGGERS */
214
215/* Trigger specific functions */
216#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
217extern void ledtrig_ide_activity(void);
218#else
219static inline void ledtrig_ide_activity(void) {}
220#endif
221
222#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
223extern void ledtrig_flash_ctrl(bool on);
224extern void ledtrig_torch_ctrl(bool on);
225#else
226static inline void ledtrig_flash_ctrl(bool on) {}
227static inline void ledtrig_torch_ctrl(bool on) {}
228#endif
229
230/*
231 * Generic LED platform data for describing LED names and default triggers.
232 */
233struct led_info {
234 const char *name;
235 const char *default_trigger;
236 int flags;
237};
238
239struct led_platform_data {
240 int num_leds;
241 struct led_info *leds;
242};
243
244/* For the leds-gpio driver */
245struct gpio_led {
246 const char *name;
247 const char *default_trigger;
248 unsigned gpio;
249 unsigned active_low : 1;
250 unsigned retain_state_suspended : 1;
251 unsigned default_state : 2;
252 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
253};
254#define LEDS_GPIO_DEFSTATE_OFF 0
255#define LEDS_GPIO_DEFSTATE_ON 1
256#define LEDS_GPIO_DEFSTATE_KEEP 2
257
258struct gpio_led_platform_data {
259 int num_leds;
260 const struct gpio_led *leds;
261
262#define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
263#define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
264#define GPIO_LED_BLINK 2 /* Please, blink */
265 int (*gpio_blink_set)(unsigned gpio, int state,
266 unsigned long *delay_on,
267 unsigned long *delay_off);
268};
269
270struct platform_device *gpio_led_register_device(
271 int id, const struct gpio_led_platform_data *pdata);
272
273enum cpu_led_event {
274 CPU_LED_IDLE_START, /* CPU enters idle */
275 CPU_LED_IDLE_END, /* CPU idle ends */
276 CPU_LED_START, /* Machine starts, especially resume */
277 CPU_LED_STOP, /* Machine stops, especially suspend */
278 CPU_LED_HALTED, /* Machine shutdown */
279};
280#ifdef CONFIG_LEDS_TRIGGER_CPU
281extern void ledtrig_cpu(enum cpu_led_event evt);
282#else
283static inline void ledtrig_cpu(enum cpu_led_event evt)
284{
285 return;
286}
287#endif
288
289#endif /* __LINUX_LEDS_H_INCLUDED */