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/rwsem.h>
17 #include <linux/spinlock.h>
18 #include <linux/timer.h>
19 #include <linux/workqueue.h>
20
21 struct device;
22 /*
23 * LED Core
24 */
25
26 enum led_brightness {
27 LED_OFF = 0,
28 LED_HALF = 127,
29 LED_FULL = 255,
30 };
31
32 struct led_classdev {
33 const char *name;
34 enum led_brightness brightness;
35 enum led_brightness max_brightness;
36 int flags;
37
38 /* Lower 16 bits reflect status */
39 #define LED_SUSPENDED (1 << 0)
40 /* Upper 16 bits reflect control information */
41 #define LED_CORE_SUSPENDRESUME (1 << 16)
42 #define LED_BLINK_ONESHOT (1 << 17)
43 #define LED_BLINK_ONESHOT_STOP (1 << 18)
44 #define LED_BLINK_INVERT (1 << 19)
45
46 /* Set LED brightness level */
47 /* Must not sleep, use a workqueue if needed */
48 void (*brightness_set)(struct led_classdev *led_cdev,
49 enum led_brightness brightness);
50 /* Get LED brightness level */
51 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
52
53 /*
54 * Activate hardware accelerated blink, delays are in milliseconds
55 * and if both are zero then a sensible default should be chosen.
56 * The call should adjust the timings in that case and if it can't
57 * match the values specified exactly.
58 * Deactivate blinking again when the brightness is set to a fixed
59 * value via the brightness_set() callback.
60 */
61 int (*blink_set)(struct led_classdev *led_cdev,
62 unsigned long *delay_on,
63 unsigned long *delay_off);
64
65 struct device *dev;
66 const struct attribute_group **groups;
67
68 struct list_head node; /* LED Device list */
69 const char *default_trigger; /* Trigger to use */
70
71 unsigned long blink_delay_on, blink_delay_off;
72 struct timer_list blink_timer;
73 int blink_brightness;
74
75 struct work_struct set_brightness_work;
76 int delayed_set_value;
77
78 #ifdef CONFIG_LEDS_TRIGGERS
79 /* Protects the trigger data below */
80 struct rw_semaphore trigger_lock;
81
82 struct led_trigger *trigger;
83 struct list_head trig_list;
84 void *trigger_data;
85 /* true if activated - deactivate routine uses it to do cleanup */
86 bool activated;
87 #endif
88 };
89
90 extern int led_classdev_register(struct device *parent,
91 struct led_classdev *led_cdev);
92 extern void led_classdev_unregister(struct led_classdev *led_cdev);
93 extern void led_classdev_suspend(struct led_classdev *led_cdev);
94 extern void led_classdev_resume(struct led_classdev *led_cdev);
95
96 /**
97 * led_blink_set - set blinking with software fallback
98 * @led_cdev: the LED to start blinking
99 * @delay_on: the time it should be on (in ms)
100 * @delay_off: the time it should ble off (in ms)
101 *
102 * This function makes the LED blink, attempting to use the
103 * hardware acceleration if possible, but falling back to
104 * software blinking if there is no hardware blinking or if
105 * the LED refuses the passed values.
106 *
107 * Note that if software blinking is active, simply calling
108 * led_cdev->brightness_set() will not stop the blinking,
109 * use led_classdev_brightness_set() instead.
110 */
111 extern void led_blink_set(struct led_classdev *led_cdev,
112 unsigned long *delay_on,
113 unsigned long *delay_off);
114 /**
115 * led_blink_set_oneshot - do a oneshot software blink
116 * @led_cdev: the LED to start blinking
117 * @delay_on: the time it should be on (in ms)
118 * @delay_off: the time it should ble off (in ms)
119 * @invert: blink off, then on, leaving the led on
120 *
121 * This function makes the LED blink one time for delay_on +
122 * delay_off time, ignoring the request if another one-shot
123 * blink is already in progress.
124 *
125 * If invert is set, led blinks for delay_off first, then for
126 * delay_on and leave the led on after the on-off cycle.
127 */
128 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
129 unsigned long *delay_on,
130 unsigned long *delay_off,
131 int invert);
132 /**
133 * led_set_brightness - set LED brightness
134 * @led_cdev: the LED to set
135 * @brightness: the brightness to set it to
136 *
137 * Set an LED's brightness, and, if necessary, cancel the
138 * software blink timer that implements blinking when the
139 * hardware doesn't.
140 */
141 extern void led_set_brightness(struct led_classdev *led_cdev,
142 enum led_brightness brightness);
143 /**
144 * led_update_brightness - update LED brightness
145 * @led_cdev: the LED to query
146 *
147 * Get an LED's current brightness and update led_cdev->brightness
148 * member with the obtained value.
149 *
150 * Returns: 0 on success or negative error value on failure
151 */
152 extern int led_update_brightness(struct led_classdev *led_cdev);
153
154 /*
155 * LED Triggers
156 */
157 /* Registration functions for simple triggers */
158 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
159 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
160
161 #ifdef CONFIG_LEDS_TRIGGERS
162
163 #define TRIG_NAME_MAX 50
164
165 struct led_trigger {
166 /* Trigger Properties */
167 const char *name;
168 void (*activate)(struct led_classdev *led_cdev);
169 void (*deactivate)(struct led_classdev *led_cdev);
170
171 /* LEDs under control by this trigger (for simple triggers) */
172 rwlock_t leddev_list_lock;
173 struct list_head led_cdevs;
174
175 /* Link to next registered trigger */
176 struct list_head next_trig;
177 };
178
179 /* Registration functions for complex triggers */
180 extern int led_trigger_register(struct led_trigger *trigger);
181 extern void led_trigger_unregister(struct led_trigger *trigger);
182
183 extern void led_trigger_register_simple(const char *name,
184 struct led_trigger **trigger);
185 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
186 extern void led_trigger_event(struct led_trigger *trigger,
187 enum led_brightness event);
188 extern void led_trigger_blink(struct led_trigger *trigger,
189 unsigned long *delay_on,
190 unsigned long *delay_off);
191 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
192 unsigned long *delay_on,
193 unsigned long *delay_off,
194 int invert);
195 /**
196 * led_trigger_rename_static - rename a trigger
197 * @name: the new trigger name
198 * @trig: the LED trigger to rename
199 *
200 * Change a LED trigger name by copying the string passed in
201 * name into current trigger name, which MUST be large
202 * enough for the new string.
203 *
204 * Note that name must NOT point to the same string used
205 * during LED registration, as that could lead to races.
206 *
207 * This is meant to be used on triggers with statically
208 * allocated name.
209 */
210 extern void led_trigger_rename_static(const char *name,
211 struct led_trigger *trig);
212
213 #else
214
215 /* Trigger has no members */
216 struct led_trigger {};
217
218 /* Trigger inline empty functions */
led_trigger_register_simple(const char * name,struct led_trigger ** trigger)219 static inline void led_trigger_register_simple(const char *name,
220 struct led_trigger **trigger) {}
led_trigger_unregister_simple(struct led_trigger * trigger)221 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
led_trigger_event(struct led_trigger * trigger,enum led_brightness event)222 static inline void led_trigger_event(struct led_trigger *trigger,
223 enum led_brightness event) {}
224 #endif /* CONFIG_LEDS_TRIGGERS */
225
226 /* Trigger specific functions */
227 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
228 extern void ledtrig_ide_activity(void);
229 #else
ledtrig_ide_activity(void)230 static inline void ledtrig_ide_activity(void) {}
231 #endif
232
233 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
234 extern void ledtrig_flash_ctrl(bool on);
235 extern void ledtrig_torch_ctrl(bool on);
236 #else
ledtrig_flash_ctrl(bool on)237 static inline void ledtrig_flash_ctrl(bool on) {}
ledtrig_torch_ctrl(bool on)238 static inline void ledtrig_torch_ctrl(bool on) {}
239 #endif
240
241 /*
242 * Generic LED platform data for describing LED names and default triggers.
243 */
244 struct led_info {
245 const char *name;
246 const char *default_trigger;
247 int flags;
248 };
249
250 struct led_platform_data {
251 int num_leds;
252 struct led_info *leds;
253 };
254
255 /* For the leds-gpio driver */
256 struct gpio_led {
257 const char *name;
258 const char *default_trigger;
259 unsigned gpio;
260 unsigned active_low : 1;
261 unsigned retain_state_suspended : 1;
262 unsigned default_state : 2;
263 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
264 };
265 #define LEDS_GPIO_DEFSTATE_OFF 0
266 #define LEDS_GPIO_DEFSTATE_ON 1
267 #define LEDS_GPIO_DEFSTATE_KEEP 2
268
269 struct gpio_led_platform_data {
270 int num_leds;
271 const struct gpio_led *leds;
272
273 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
274 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
275 #define GPIO_LED_BLINK 2 /* Please, blink */
276 int (*gpio_blink_set)(unsigned gpio, int state,
277 unsigned long *delay_on,
278 unsigned long *delay_off);
279 };
280
281 struct platform_device *gpio_led_register_device(
282 int id, const struct gpio_led_platform_data *pdata);
283
284 enum cpu_led_event {
285 CPU_LED_IDLE_START, /* CPU enters idle */
286 CPU_LED_IDLE_END, /* CPU idle ends */
287 CPU_LED_START, /* Machine starts, especially resume */
288 CPU_LED_STOP, /* Machine stops, especially suspend */
289 CPU_LED_HALTED, /* Machine shutdown */
290 };
291 #ifdef CONFIG_LEDS_TRIGGER_CPU
292 extern void ledtrig_cpu(enum cpu_led_event evt);
293 #else
ledtrig_cpu(enum cpu_led_event evt)294 static inline void ledtrig_cpu(enum cpu_led_event evt)
295 {
296 return;
297 }
298 #endif
299
300 #endif /* __LINUX_LEDS_H_INCLUDED */
301