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Richard Purdiec3bc9952006-03-31 02:31:05 -08001/*
2 * LED Triggers Core
3 *
Richard Purdief8a7c6f2007-07-08 23:19:31 +01004 * Copyright 2005-2007 Openedhand Ltd.
Richard Purdiec3bc9952006-03-31 02:31:05 -08005 *
6 * Author: Richard Purdie <rpurdie@openedhand.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
Richard Purdiec3bc9952006-03-31 02:31:05 -080014#include <linux/module.h>
15#include <linux/kernel.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080016#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <linux/device.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080019#include <linux/timer.h>
Richard Purdiedc472062007-11-10 13:29:04 +000020#include <linux/rwsem.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080021#include <linux/leds.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/slab.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080023#include "leds.h"
24
25/*
26 * Nests outside led_cdev->trigger_lock
27 */
Richard Purdiedc472062007-11-10 13:29:04 +000028static DECLARE_RWSEM(triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080029static LIST_HEAD(trigger_list);
30
Németh Márton4d404fd2008-03-09 20:59:57 +000031 /* Used by LED Class */
32
Richard Purdief8a7c6f2007-07-08 23:19:31 +010033ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
34 const char *buf, size_t count)
Richard Purdiec3bc9952006-03-31 02:31:05 -080035{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010036 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080037 char trigger_name[TRIG_NAME_MAX];
38 struct led_trigger *trig;
39 size_t len;
Jacek Anaszewskiacd899e2014-09-22 08:21:04 -070040 int ret = count;
41
42 mutex_lock(&led_cdev->led_access);
43
44 if (led_sysfs_is_disabled(led_cdev)) {
45 ret = -EBUSY;
46 goto unlock;
47 }
Richard Purdiec3bc9952006-03-31 02:31:05 -080048
49 trigger_name[sizeof(trigger_name) - 1] = '\0';
50 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
51 len = strlen(trigger_name);
52
53 if (len && trigger_name[len - 1] == '\n')
54 trigger_name[len - 1] = '\0';
55
56 if (!strcmp(trigger_name, "none")) {
Németh Márton0013b232008-03-09 20:54:37 +000057 led_trigger_remove(led_cdev);
Jacek Anaszewskiacd899e2014-09-22 08:21:04 -070058 goto unlock;
Richard Purdiec3bc9952006-03-31 02:31:05 -080059 }
60
Richard Purdiedc472062007-11-10 13:29:04 +000061 down_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080062 list_for_each_entry(trig, &trigger_list, next_trig) {
63 if (!strcmp(trigger_name, trig->name)) {
Richard Purdiedc472062007-11-10 13:29:04 +000064 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080065 led_trigger_set(led_cdev, trig);
Richard Purdiedc472062007-11-10 13:29:04 +000066 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080067
Richard Purdiedc472062007-11-10 13:29:04 +000068 up_read(&triggers_list_lock);
Jacek Anaszewskiacd899e2014-09-22 08:21:04 -070069 goto unlock;
Richard Purdiec3bc9952006-03-31 02:31:05 -080070 }
71 }
Richard Purdiedc472062007-11-10 13:29:04 +000072 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080073
Jacek Anaszewskiacd899e2014-09-22 08:21:04 -070074unlock:
75 mutex_unlock(&led_cdev->led_access);
76 return ret;
Richard Purdiec3bc9952006-03-31 02:31:05 -080077}
Németh Márton4d404fd2008-03-09 20:59:57 +000078EXPORT_SYMBOL_GPL(led_trigger_store);
Richard Purdiec3bc9952006-03-31 02:31:05 -080079
Richard Purdief8a7c6f2007-07-08 23:19:31 +010080ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
81 char *buf)
Richard Purdiec3bc9952006-03-31 02:31:05 -080082{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010083 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080084 struct led_trigger *trig;
85 int len = 0;
86
Richard Purdiedc472062007-11-10 13:29:04 +000087 down_read(&triggers_list_lock);
88 down_read(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080089
90 if (!led_cdev->trigger)
91 len += sprintf(buf+len, "[none] ");
92 else
93 len += sprintf(buf+len, "none ");
94
95 list_for_each_entry(trig, &trigger_list, next_trig) {
96 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
97 trig->name))
98 len += sprintf(buf+len, "[%s] ", trig->name);
99 else
100 len += sprintf(buf+len, "%s ", trig->name);
101 }
Richard Purdiedc472062007-11-10 13:29:04 +0000102 up_read(&led_cdev->trigger_lock);
103 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800104
105 len += sprintf(len+buf, "\n");
106 return len;
107}
Németh Márton4d404fd2008-03-09 20:59:57 +0000108EXPORT_SYMBOL_GPL(led_trigger_show);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800109
110/* Caller must ensure led_cdev->trigger_lock held */
Bryan Wueb202622012-04-19 11:46:33 +0800111void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
Richard Purdiec3bc9952006-03-31 02:31:05 -0800112{
113 unsigned long flags;
Colin Cross52c47742012-08-27 09:31:49 +0800114 char *event = NULL;
115 char *envp[2];
116 const char *name;
117
118 name = trig ? trig->name : "none";
119 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800120
121 /* Remove any existing trigger */
122 if (led_cdev->trigger) {
123 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
124 list_del(&led_cdev->trig_list);
Németh Márton4d404fd2008-03-09 20:59:57 +0000125 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
126 flags);
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800127 cancel_work_sync(&led_cdev->set_brightness_work);
128 led_stop_software_blink(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800129 if (led_cdev->trigger->deactivate)
130 led_cdev->trigger->deactivate(led_cdev);
Dmitry Baryshkovfe3025b2008-07-16 22:51:14 +0100131 led_cdev->trigger = NULL;
Shuah Khan19cd67e2012-06-14 04:34:30 +0800132 led_set_brightness(led_cdev, LED_OFF);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800133 }
Bryan Wueb202622012-04-19 11:46:33 +0800134 if (trig) {
135 write_lock_irqsave(&trig->leddev_list_lock, flags);
136 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
137 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
138 led_cdev->trigger = trig;
139 if (trig->activate)
140 trig->activate(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800141 }
Colin Cross52c47742012-08-27 09:31:49 +0800142
143 if (event) {
144 envp[0] = event;
145 envp[1] = NULL;
146 kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
147 kfree(event);
148 }
Richard Purdiec3bc9952006-03-31 02:31:05 -0800149}
Németh Márton4d404fd2008-03-09 20:59:57 +0000150EXPORT_SYMBOL_GPL(led_trigger_set);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800151
Németh Márton0013b232008-03-09 20:54:37 +0000152void led_trigger_remove(struct led_classdev *led_cdev)
153{
154 down_write(&led_cdev->trigger_lock);
155 led_trigger_set(led_cdev, NULL);
156 up_write(&led_cdev->trigger_lock);
157}
Németh Márton4d404fd2008-03-09 20:59:57 +0000158EXPORT_SYMBOL_GPL(led_trigger_remove);
Németh Márton0013b232008-03-09 20:54:37 +0000159
Richard Purdiec3bc9952006-03-31 02:31:05 -0800160void led_trigger_set_default(struct led_classdev *led_cdev)
161{
162 struct led_trigger *trig;
163
164 if (!led_cdev->default_trigger)
165 return;
166
Richard Purdiedc472062007-11-10 13:29:04 +0000167 down_read(&triggers_list_lock);
168 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800169 list_for_each_entry(trig, &trigger_list, next_trig) {
170 if (!strcmp(led_cdev->default_trigger, trig->name))
171 led_trigger_set(led_cdev, trig);
172 }
Richard Purdiedc472062007-11-10 13:29:04 +0000173 up_write(&led_cdev->trigger_lock);
174 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800175}
Németh Márton4d404fd2008-03-09 20:59:57 +0000176EXPORT_SYMBOL_GPL(led_trigger_set_default);
177
Fabio Baltieria8df7b12012-11-04 01:54:34 -0800178void led_trigger_rename_static(const char *name, struct led_trigger *trig)
179{
180 /* new name must be on a temporary string to prevent races */
181 BUG_ON(name == trig->name);
182
183 down_write(&triggers_list_lock);
184 /* this assumes that trig->name was originaly allocated to
185 * non constant storage */
186 strcpy((char *)trig->name, name);
187 up_write(&triggers_list_lock);
188}
189EXPORT_SYMBOL_GPL(led_trigger_rename_static);
190
Németh Márton4d404fd2008-03-09 20:59:57 +0000191/* LED Trigger Interface */
Richard Purdiec3bc9952006-03-31 02:31:05 -0800192
Bryan Wueb202622012-04-19 11:46:33 +0800193int led_trigger_register(struct led_trigger *trig)
Richard Purdiec3bc9952006-03-31 02:31:05 -0800194{
195 struct led_classdev *led_cdev;
Bryan Wueb202622012-04-19 11:46:33 +0800196 struct led_trigger *_trig;
Richard Purdiec3bc9952006-03-31 02:31:05 -0800197
Bryan Wueb202622012-04-19 11:46:33 +0800198 rwlock_init(&trig->leddev_list_lock);
199 INIT_LIST_HEAD(&trig->led_cdevs);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800200
Richard Purdiedc472062007-11-10 13:29:04 +0000201 down_write(&triggers_list_lock);
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000202 /* Make sure the trigger's name isn't already in use */
Bryan Wueb202622012-04-19 11:46:33 +0800203 list_for_each_entry(_trig, &trigger_list, next_trig) {
204 if (!strcmp(_trig->name, trig->name)) {
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000205 up_write(&triggers_list_lock);
206 return -EEXIST;
207 }
208 }
209 /* Add to the list of led triggers */
Bryan Wueb202622012-04-19 11:46:33 +0800210 list_add_tail(&trig->next_trig, &trigger_list);
Richard Purdiedc472062007-11-10 13:29:04 +0000211 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800212
213 /* Register with any LEDs that have this as a default trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000214 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800215 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000216 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800217 if (!led_cdev->trigger && led_cdev->default_trigger &&
Bryan Wueb202622012-04-19 11:46:33 +0800218 !strcmp(led_cdev->default_trigger, trig->name))
219 led_trigger_set(led_cdev, trig);
Richard Purdiedc472062007-11-10 13:29:04 +0000220 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800221 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000222 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800223
224 return 0;
225}
Németh Márton4d404fd2008-03-09 20:59:57 +0000226EXPORT_SYMBOL_GPL(led_trigger_register);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800227
Bryan Wueb202622012-04-19 11:46:33 +0800228void led_trigger_unregister(struct led_trigger *trig)
Richard Purdiec3bc9952006-03-31 02:31:05 -0800229{
230 struct led_classdev *led_cdev;
231
Sasha Levin14f57162014-04-04 10:01:13 -0700232 if (list_empty_careful(&trig->next_trig))
233 return;
234
Richard Purdiec3bc9952006-03-31 02:31:05 -0800235 /* Remove from the list of led triggers */
Richard Purdiedc472062007-11-10 13:29:04 +0000236 down_write(&triggers_list_lock);
Sasha Levin14f57162014-04-04 10:01:13 -0700237 list_del_init(&trig->next_trig);
Richard Purdiedc472062007-11-10 13:29:04 +0000238 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800239
240 /* Remove anyone actively using this trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000241 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800242 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000243 down_write(&led_cdev->trigger_lock);
Bryan Wueb202622012-04-19 11:46:33 +0800244 if (led_cdev->trigger == trig)
Richard Purdiec3bc9952006-03-31 02:31:05 -0800245 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000246 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800247 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000248 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800249}
Németh Márton4d404fd2008-03-09 20:59:57 +0000250EXPORT_SYMBOL_GPL(led_trigger_unregister);
251
Heiner Kallweit9534cc32016-01-02 01:36:41 +0100252static void devm_led_trigger_release(struct device *dev, void *res)
253{
254 led_trigger_unregister(*(struct led_trigger **)res);
255}
256
257int devm_led_trigger_register(struct device *dev,
258 struct led_trigger *trig)
259{
260 struct led_trigger **dr;
261 int rc;
262
263 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
264 GFP_KERNEL);
265 if (!dr)
266 return -ENOMEM;
267
268 *dr = trig;
269
270 rc = led_trigger_register(trig);
271 if (rc)
272 devres_free(dr);
273 else
274 devres_add(dev, dr);
275
276 return rc;
277}
278EXPORT_SYMBOL_GPL(devm_led_trigger_register);
279
Németh Márton4d404fd2008-03-09 20:59:57 +0000280/* Simple LED Tigger Interface */
281
Bryan Wueb202622012-04-19 11:46:33 +0800282void led_trigger_event(struct led_trigger *trig,
Németh Márton4d404fd2008-03-09 20:59:57 +0000283 enum led_brightness brightness)
284{
ZHAO Gang11e043b2013-12-28 07:00:26 -0800285 struct led_classdev *led_cdev;
Németh Márton4d404fd2008-03-09 20:59:57 +0000286
Bryan Wueb202622012-04-19 11:46:33 +0800287 if (!trig)
Németh Márton4d404fd2008-03-09 20:59:57 +0000288 return;
289
Bryan Wueb202622012-04-19 11:46:33 +0800290 read_lock(&trig->leddev_list_lock);
ZHAO Gang11e043b2013-12-28 07:00:26 -0800291 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800292 led_set_brightness(led_cdev, brightness);
Bryan Wueb202622012-04-19 11:46:33 +0800293 read_unlock(&trig->leddev_list_lock);
Németh Márton4d404fd2008-03-09 20:59:57 +0000294}
295EXPORT_SYMBOL_GPL(led_trigger_event);
296
Bryan Wu20c0e6b2012-06-15 22:15:27 +0800297static void led_trigger_blink_setup(struct led_trigger *trig,
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800298 unsigned long *delay_on,
299 unsigned long *delay_off,
300 int oneshot,
301 int invert)
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000302{
ZHAO Gang11e043b2013-12-28 07:00:26 -0800303 struct led_classdev *led_cdev;
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000304
Bryan Wueb202622012-04-19 11:46:33 +0800305 if (!trig)
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000306 return;
307
Bryan Wueb202622012-04-19 11:46:33 +0800308 read_lock(&trig->leddev_list_lock);
ZHAO Gang11e043b2013-12-28 07:00:26 -0800309 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800310 if (oneshot)
311 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
312 invert);
313 else
314 led_blink_set(led_cdev, delay_on, delay_off);
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000315 }
Bryan Wueb202622012-04-19 11:46:33 +0800316 read_unlock(&trig->leddev_list_lock);
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000317}
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800318
319void led_trigger_blink(struct led_trigger *trig,
320 unsigned long *delay_on,
321 unsigned long *delay_off)
322{
323 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
324}
Vasily Khoruzhick0b9536c2011-01-07 16:28:16 +0000325EXPORT_SYMBOL_GPL(led_trigger_blink);
326
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800327void led_trigger_blink_oneshot(struct led_trigger *trig,
328 unsigned long *delay_on,
329 unsigned long *delay_off,
330 int invert)
331{
332 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
333}
334EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
335
Németh Márton4d404fd2008-03-09 20:59:57 +0000336void led_trigger_register_simple(const char *name, struct led_trigger **tp)
337{
Bryan Wueb202622012-04-19 11:46:33 +0800338 struct led_trigger *trig;
Németh Márton4d404fd2008-03-09 20:59:57 +0000339 int err;
340
Bryan Wueb202622012-04-19 11:46:33 +0800341 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
Németh Márton4d404fd2008-03-09 20:59:57 +0000342
Bryan Wueb202622012-04-19 11:46:33 +0800343 if (trig) {
344 trig->name = name;
345 err = led_trigger_register(trig);
Masakazu Mokunocba4c2a2011-10-31 17:11:59 -0700346 if (err < 0) {
Bryan Wueb202622012-04-19 11:46:33 +0800347 kfree(trig);
348 trig = NULL;
Sachin Kamat09f5fe72012-11-25 13:00:44 +0530349 pr_warn("LED trigger %s failed to register (%d)\n",
350 name, err);
Masakazu Mokunocba4c2a2011-10-31 17:11:59 -0700351 }
Sachin Kamat09f5fe72012-11-25 13:00:44 +0530352 } else {
353 pr_warn("LED trigger %s failed to register (no memory)\n",
354 name);
355 }
Bryan Wueb202622012-04-19 11:46:33 +0800356 *tp = trig;
Németh Márton4d404fd2008-03-09 20:59:57 +0000357}
358EXPORT_SYMBOL_GPL(led_trigger_register_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800359
Bryan Wueb202622012-04-19 11:46:33 +0800360void led_trigger_unregister_simple(struct led_trigger *trig)
Richard Purdiec3bc9952006-03-31 02:31:05 -0800361{
Bryan Wueb202622012-04-19 11:46:33 +0800362 if (trig)
363 led_trigger_unregister(trig);
364 kfree(trig);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800365}
Richard Purdiec3bc9952006-03-31 02:31:05 -0800366EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800367
368MODULE_AUTHOR("Richard Purdie");
369MODULE_LICENSE("GPL");
370MODULE_DESCRIPTION("LED Triggers Core");