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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Triggers Core
4 *
5 * Copyright 2005-2007 Openedhand Ltd.
6 *
7 * Author: Richard Purdie <rpurdie@openedhand.com>
8 */
9
10#include <linux/export.h>
11#include <linux/kernel.h>
12#include <linux/list.h>
13#include <linux/spinlock.h>
14#include <linux/device.h>
15#include <linux/timer.h>
16#include <linux/rwsem.h>
17#include <linux/leds.h>
18#include <linux/slab.h>
19#include <linux/mm.h>
20#include "leds.h"
21
22/*
23 * Nests outside led_cdev->trigger_lock
24 */
25static DECLARE_RWSEM(triggers_list_lock);
26LIST_HEAD(trigger_list);
27
28 /* Used by LED Class */
29
30static inline bool
31trigger_relevant(struct led_classdev *led_cdev, struct led_trigger *trig)
32{
33 return !trig->trigger_type || trig->trigger_type == led_cdev->trigger_type;
34}
35
36ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
37 struct bin_attribute *bin_attr, char *buf,
38 loff_t pos, size_t count)
39{
40 struct device *dev = kobj_to_dev(kobj);
41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
42 struct led_trigger *trig;
43 int ret = count;
44
45 mutex_lock(&led_cdev->led_access);
46
47 if (led_sysfs_is_disabled(led_cdev)) {
48 ret = -EBUSY;
49 goto unlock;
50 }
51
52 if (sysfs_streq(buf, "none")) {
53 led_trigger_remove(led_cdev);
54 goto unlock;
55 }
56
57 down_read(&triggers_list_lock);
58 list_for_each_entry(trig, &trigger_list, next_trig) {
59 if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {
60 down_write(&led_cdev->trigger_lock);
61 led_trigger_set(led_cdev, trig);
62 up_write(&led_cdev->trigger_lock);
63
64 up_read(&triggers_list_lock);
65 goto unlock;
66 }
67 }
68 /* we come here only if buf matches no trigger */
69 ret = -EINVAL;
70 up_read(&triggers_list_lock);
71
72unlock:
73 mutex_unlock(&led_cdev->led_access);
74 return ret;
75}
76EXPORT_SYMBOL_GPL(led_trigger_write);
77
78__printf(3, 4)
79static int led_trigger_snprintf(char *buf, ssize_t size, const char *fmt, ...)
80{
81 va_list args;
82 int i;
83
84 va_start(args, fmt);
85 if (size <= 0)
86 i = vsnprintf(NULL, 0, fmt, args);
87 else
88 i = vscnprintf(buf, size, fmt, args);
89 va_end(args);
90
91 return i;
92}
93
94static int led_trigger_format(char *buf, size_t size,
95 struct led_classdev *led_cdev)
96{
97 struct led_trigger *trig;
98 int len = led_trigger_snprintf(buf, size, "%s",
99 led_cdev->trigger ? "none" : "[none]");
100
101 list_for_each_entry(trig, &trigger_list, next_trig) {
102 bool hit;
103
104 if (!trigger_relevant(led_cdev, trig))
105 continue;
106
107 hit = led_cdev->trigger && !strcmp(led_cdev->trigger->name, trig->name);
108
109 len += led_trigger_snprintf(buf + len, size - len,
110 " %s%s%s", hit ? "[" : "",
111 trig->name, hit ? "]" : "");
112 }
113
114 len += led_trigger_snprintf(buf + len, size - len, "\n");
115
116 return len;
117}
118
119/*
120 * It was stupid to create 10000 cpu triggers, but we are stuck with it now.
121 * Don't make that mistake again. We work around it here by creating binary
122 * attribute, which is not limited by length. This is _not_ good design, do not
123 * copy it.
124 */
125ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
126 struct bin_attribute *attr, char *buf,
127 loff_t pos, size_t count)
128{
129 struct device *dev = kobj_to_dev(kobj);
130 struct led_classdev *led_cdev = dev_get_drvdata(dev);
131 void *data;
132 int len;
133
134 down_read(&triggers_list_lock);
135 down_read(&led_cdev->trigger_lock);
136
137 len = led_trigger_format(NULL, 0, led_cdev);
138 data = kvmalloc(len + 1, GFP_KERNEL);
139 if (!data) {
140 up_read(&led_cdev->trigger_lock);
141 up_read(&triggers_list_lock);
142 return -ENOMEM;
143 }
144 len = led_trigger_format(data, len + 1, led_cdev);
145
146 up_read(&led_cdev->trigger_lock);
147 up_read(&triggers_list_lock);
148
149 len = memory_read_from_buffer(buf, count, &pos, data, len);
150
151 kvfree(data);
152
153 return len;
154}
155EXPORT_SYMBOL_GPL(led_trigger_read);
156
157/* Caller must ensure led_cdev->trigger_lock held */
158int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
159{
160 char *event = NULL;
161 char *envp[2];
162 const char *name;
163 int ret;
164
165 if (!led_cdev->trigger && !trig)
166 return 0;
167
168 name = trig ? trig->name : "none";
169 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
170
171 /* Remove any existing trigger */
172 if (led_cdev->trigger) {
173 spin_lock(&led_cdev->trigger->leddev_list_lock);
174 list_del_rcu(&led_cdev->trig_list);
175 spin_unlock(&led_cdev->trigger->leddev_list_lock);
176
177 /* ensure it's no longer visible on the led_cdevs list */
178 synchronize_rcu();
179
180 cancel_work_sync(&led_cdev->set_brightness_work);
181 led_stop_software_blink(led_cdev);
182 if (led_cdev->trigger->deactivate)
183 led_cdev->trigger->deactivate(led_cdev);
184 device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
185 led_cdev->trigger = NULL;
186 led_cdev->trigger_data = NULL;
187 led_cdev->activated = false;
188 led_set_brightness(led_cdev, LED_OFF);
189 }
190 if (trig) {
191 spin_lock(&trig->leddev_list_lock);
192 list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);
193 spin_unlock(&trig->leddev_list_lock);
194 led_cdev->trigger = trig;
195
196 if (trig->activate)
197 ret = trig->activate(led_cdev);
198 else
199 ret = 0;
200
201 if (ret)
202 goto err_activate;
203
204 ret = device_add_groups(led_cdev->dev, trig->groups);
205 if (ret) {
206 dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
207 goto err_add_groups;
208 }
209 }
210
211 if (event) {
212 envp[0] = event;
213 envp[1] = NULL;
214 if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
215 dev_err(led_cdev->dev,
216 "%s: Error sending uevent\n", __func__);
217 kfree(event);
218 }
219
220 return 0;
221
222err_add_groups:
223
224 if (trig->deactivate)
225 trig->deactivate(led_cdev);
226err_activate:
227
228 spin_lock(&led_cdev->trigger->leddev_list_lock);
229 list_del_rcu(&led_cdev->trig_list);
230 spin_unlock(&led_cdev->trigger->leddev_list_lock);
231 synchronize_rcu();
232 led_cdev->trigger = NULL;
233 led_cdev->trigger_data = NULL;
234 led_set_brightness(led_cdev, LED_OFF);
235 kfree(event);
236
237 return ret;
238}
239EXPORT_SYMBOL_GPL(led_trigger_set);
240
241void led_trigger_remove(struct led_classdev *led_cdev)
242{
243 down_write(&led_cdev->trigger_lock);
244 led_trigger_set(led_cdev, NULL);
245 up_write(&led_cdev->trigger_lock);
246}
247EXPORT_SYMBOL_GPL(led_trigger_remove);
248
249void led_trigger_set_default(struct led_classdev *led_cdev)
250{
251 struct led_trigger *trig;
252
253 if (!led_cdev->default_trigger)
254 return;
255
256 down_read(&triggers_list_lock);
257 down_write(&led_cdev->trigger_lock);
258 list_for_each_entry(trig, &trigger_list, next_trig) {
259 if (!strcmp(led_cdev->default_trigger, trig->name) &&
260 trigger_relevant(led_cdev, trig)) {
261 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
262 led_trigger_set(led_cdev, trig);
263 break;
264 }
265 }
266 up_write(&led_cdev->trigger_lock);
267 up_read(&triggers_list_lock);
268}
269EXPORT_SYMBOL_GPL(led_trigger_set_default);
270
271void led_trigger_rename_static(const char *name, struct led_trigger *trig)
272{
273 /* new name must be on a temporary string to prevent races */
274 BUG_ON(name == trig->name);
275
276 down_write(&triggers_list_lock);
277 /* this assumes that trig->name was originaly allocated to
278 * non constant storage */
279 strcpy((char *)trig->name, name);
280 up_write(&triggers_list_lock);
281}
282EXPORT_SYMBOL_GPL(led_trigger_rename_static);
283
284/* LED Trigger Interface */
285
286int led_trigger_register(struct led_trigger *trig)
287{
288 struct led_classdev *led_cdev;
289 struct led_trigger *_trig;
290
291 spin_lock_init(&trig->leddev_list_lock);
292 INIT_LIST_HEAD(&trig->led_cdevs);
293
294 down_write(&triggers_list_lock);
295 /* Make sure the trigger's name isn't already in use */
296 list_for_each_entry(_trig, &trigger_list, next_trig) {
297 if (!strcmp(_trig->name, trig->name) &&
298 (trig->trigger_type == _trig->trigger_type ||
299 !trig->trigger_type || !_trig->trigger_type)) {
300 up_write(&triggers_list_lock);
301 return -EEXIST;
302 }
303 }
304 /* Add to the list of led triggers */
305 list_add_tail(&trig->next_trig, &trigger_list);
306 up_write(&triggers_list_lock);
307
308 /* Register with any LEDs that have this as a default trigger */
309 down_read(&leds_list_lock);
310 list_for_each_entry(led_cdev, &leds_list, node) {
311 down_write(&led_cdev->trigger_lock);
312 if (!led_cdev->trigger && led_cdev->default_trigger &&
313 !strcmp(led_cdev->default_trigger, trig->name) &&
314 trigger_relevant(led_cdev, trig)) {
315 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
316 led_trigger_set(led_cdev, trig);
317 }
318 up_write(&led_cdev->trigger_lock);
319 }
320 up_read(&leds_list_lock);
321
322 return 0;
323}
324EXPORT_SYMBOL_GPL(led_trigger_register);
325
326void led_trigger_unregister(struct led_trigger *trig)
327{
328 struct led_classdev *led_cdev;
329
330 if (list_empty_careful(&trig->next_trig))
331 return;
332
333 /* Remove from the list of led triggers */
334 down_write(&triggers_list_lock);
335 list_del_init(&trig->next_trig);
336 up_write(&triggers_list_lock);
337
338 /* Remove anyone actively using this trigger */
339 down_read(&leds_list_lock);
340 list_for_each_entry(led_cdev, &leds_list, node) {
341 down_write(&led_cdev->trigger_lock);
342 if (led_cdev->trigger == trig)
343 led_trigger_set(led_cdev, NULL);
344 up_write(&led_cdev->trigger_lock);
345 }
346 up_read(&leds_list_lock);
347}
348EXPORT_SYMBOL_GPL(led_trigger_unregister);
349
350static void devm_led_trigger_release(struct device *dev, void *res)
351{
352 led_trigger_unregister(*(struct led_trigger **)res);
353}
354
355int devm_led_trigger_register(struct device *dev,
356 struct led_trigger *trig)
357{
358 struct led_trigger **dr;
359 int rc;
360
361 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
362 GFP_KERNEL);
363 if (!dr)
364 return -ENOMEM;
365
366 *dr = trig;
367
368 rc = led_trigger_register(trig);
369 if (rc)
370 devres_free(dr);
371 else
372 devres_add(dev, dr);
373
374 return rc;
375}
376EXPORT_SYMBOL_GPL(devm_led_trigger_register);
377
378/* Simple LED Trigger Interface */
379
380void led_trigger_event(struct led_trigger *trig,
381 enum led_brightness brightness)
382{
383 struct led_classdev *led_cdev;
384
385 if (!trig)
386 return;
387
388 rcu_read_lock();
389 list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list)
390 led_set_brightness(led_cdev, brightness);
391 rcu_read_unlock();
392}
393EXPORT_SYMBOL_GPL(led_trigger_event);
394
395static void led_trigger_blink_setup(struct led_trigger *trig,
396 unsigned long *delay_on,
397 unsigned long *delay_off,
398 int oneshot,
399 int invert)
400{
401 struct led_classdev *led_cdev;
402
403 if (!trig)
404 return;
405
406 rcu_read_lock();
407 list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
408 if (oneshot)
409 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
410 invert);
411 else
412 led_blink_set(led_cdev, delay_on, delay_off);
413 }
414 rcu_read_unlock();
415}
416
417void led_trigger_blink(struct led_trigger *trig,
418 unsigned long *delay_on,
419 unsigned long *delay_off)
420{
421 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
422}
423EXPORT_SYMBOL_GPL(led_trigger_blink);
424
425void led_trigger_blink_oneshot(struct led_trigger *trig,
426 unsigned long *delay_on,
427 unsigned long *delay_off,
428 int invert)
429{
430 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
431}
432EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
433
434void led_trigger_register_simple(const char *name, struct led_trigger **tp)
435{
436 struct led_trigger *trig;
437 int err;
438
439 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
440
441 if (trig) {
442 trig->name = name;
443 err = led_trigger_register(trig);
444 if (err < 0) {
445 kfree(trig);
446 trig = NULL;
447 pr_warn("LED trigger %s failed to register (%d)\n",
448 name, err);
449 }
450 } else {
451 pr_warn("LED trigger %s failed to register (no memory)\n",
452 name);
453 }
454 *tp = trig;
455}
456EXPORT_SYMBOL_GPL(led_trigger_register_simple);
457
458void led_trigger_unregister_simple(struct led_trigger *trig)
459{
460 if (trig)
461 led_trigger_unregister(trig);
462 kfree(trig);
463}
464EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Triggers Core
4 *
5 * Copyright 2005-2007 Openedhand Ltd.
6 *
7 * Author: Richard Purdie <rpurdie@openedhand.com>
8 */
9
10#include <linux/export.h>
11#include <linux/kernel.h>
12#include <linux/list.h>
13#include <linux/spinlock.h>
14#include <linux/device.h>
15#include <linux/timer.h>
16#include <linux/rwsem.h>
17#include <linux/leds.h>
18#include <linux/slab.h>
19#include <linux/mm.h>
20#include "leds.h"
21
22/*
23 * Nests outside led_cdev->trigger_lock
24 */
25static DECLARE_RWSEM(triggers_list_lock);
26LIST_HEAD(trigger_list);
27
28 /* Used by LED Class */
29
30static inline bool
31trigger_relevant(struct led_classdev *led_cdev, struct led_trigger *trig)
32{
33 return !trig->trigger_type || trig->trigger_type == led_cdev->trigger_type;
34}
35
36ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
37 struct bin_attribute *bin_attr, char *buf,
38 loff_t pos, size_t count)
39{
40 struct device *dev = kobj_to_dev(kobj);
41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
42 struct led_trigger *trig;
43 int ret = count;
44
45 mutex_lock(&led_cdev->led_access);
46
47 if (led_sysfs_is_disabled(led_cdev)) {
48 ret = -EBUSY;
49 goto unlock;
50 }
51
52 if (sysfs_streq(buf, "none")) {
53 led_trigger_remove(led_cdev);
54 goto unlock;
55 }
56
57 down_read(&triggers_list_lock);
58 list_for_each_entry(trig, &trigger_list, next_trig) {
59 if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {
60 down_write(&led_cdev->trigger_lock);
61 led_trigger_set(led_cdev, trig);
62 up_write(&led_cdev->trigger_lock);
63
64 up_read(&triggers_list_lock);
65 goto unlock;
66 }
67 }
68 /* we come here only if buf matches no trigger */
69 ret = -EINVAL;
70 up_read(&triggers_list_lock);
71
72unlock:
73 mutex_unlock(&led_cdev->led_access);
74 return ret;
75}
76EXPORT_SYMBOL_GPL(led_trigger_write);
77
78__printf(3, 4)
79static int led_trigger_snprintf(char *buf, ssize_t size, const char *fmt, ...)
80{
81 va_list args;
82 int i;
83
84 va_start(args, fmt);
85 if (size <= 0)
86 i = vsnprintf(NULL, 0, fmt, args);
87 else
88 i = vscnprintf(buf, size, fmt, args);
89 va_end(args);
90
91 return i;
92}
93
94static int led_trigger_format(char *buf, size_t size,
95 struct led_classdev *led_cdev)
96{
97 struct led_trigger *trig;
98 int len = led_trigger_snprintf(buf, size, "%s",
99 led_cdev->trigger ? "none" : "[none]");
100
101 list_for_each_entry(trig, &trigger_list, next_trig) {
102 bool hit;
103
104 if (!trigger_relevant(led_cdev, trig))
105 continue;
106
107 hit = led_cdev->trigger && !strcmp(led_cdev->trigger->name, trig->name);
108
109 len += led_trigger_snprintf(buf + len, size - len,
110 " %s%s%s", hit ? "[" : "",
111 trig->name, hit ? "]" : "");
112 }
113
114 len += led_trigger_snprintf(buf + len, size - len, "\n");
115
116 return len;
117}
118
119/*
120 * It was stupid to create 10000 cpu triggers, but we are stuck with it now.
121 * Don't make that mistake again. We work around it here by creating binary
122 * attribute, which is not limited by length. This is _not_ good design, do not
123 * copy it.
124 */
125ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
126 struct bin_attribute *attr, char *buf,
127 loff_t pos, size_t count)
128{
129 struct device *dev = kobj_to_dev(kobj);
130 struct led_classdev *led_cdev = dev_get_drvdata(dev);
131 void *data;
132 int len;
133
134 down_read(&triggers_list_lock);
135 down_read(&led_cdev->trigger_lock);
136
137 len = led_trigger_format(NULL, 0, led_cdev);
138 data = kvmalloc(len + 1, GFP_KERNEL);
139 if (!data) {
140 up_read(&led_cdev->trigger_lock);
141 up_read(&triggers_list_lock);
142 return -ENOMEM;
143 }
144 len = led_trigger_format(data, len + 1, led_cdev);
145
146 up_read(&led_cdev->trigger_lock);
147 up_read(&triggers_list_lock);
148
149 len = memory_read_from_buffer(buf, count, &pos, data, len);
150
151 kvfree(data);
152
153 return len;
154}
155EXPORT_SYMBOL_GPL(led_trigger_read);
156
157/* Caller must ensure led_cdev->trigger_lock held */
158int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
159{
160 unsigned long flags;
161 char *event = NULL;
162 char *envp[2];
163 const char *name;
164 int ret;
165
166 if (!led_cdev->trigger && !trig)
167 return 0;
168
169 name = trig ? trig->name : "none";
170 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
171
172 /* Remove any existing trigger */
173 if (led_cdev->trigger) {
174 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
175 list_del(&led_cdev->trig_list);
176 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
177 flags);
178 cancel_work_sync(&led_cdev->set_brightness_work);
179 led_stop_software_blink(led_cdev);
180 if (led_cdev->trigger->deactivate)
181 led_cdev->trigger->deactivate(led_cdev);
182 device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
183 led_cdev->trigger = NULL;
184 led_cdev->trigger_data = NULL;
185 led_cdev->activated = false;
186 led_set_brightness(led_cdev, LED_OFF);
187 }
188 if (trig) {
189 write_lock_irqsave(&trig->leddev_list_lock, flags);
190 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
191 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
192 led_cdev->trigger = trig;
193
194 if (trig->activate)
195 ret = trig->activate(led_cdev);
196 else
197 ret = 0;
198
199 if (ret)
200 goto err_activate;
201
202 ret = device_add_groups(led_cdev->dev, trig->groups);
203 if (ret) {
204 dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
205 goto err_add_groups;
206 }
207 }
208
209 if (event) {
210 envp[0] = event;
211 envp[1] = NULL;
212 if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
213 dev_err(led_cdev->dev,
214 "%s: Error sending uevent\n", __func__);
215 kfree(event);
216 }
217
218 return 0;
219
220err_add_groups:
221
222 if (trig->deactivate)
223 trig->deactivate(led_cdev);
224err_activate:
225
226 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
227 list_del(&led_cdev->trig_list);
228 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
229 led_cdev->trigger = NULL;
230 led_cdev->trigger_data = NULL;
231 led_set_brightness(led_cdev, LED_OFF);
232 kfree(event);
233
234 return ret;
235}
236EXPORT_SYMBOL_GPL(led_trigger_set);
237
238void led_trigger_remove(struct led_classdev *led_cdev)
239{
240 down_write(&led_cdev->trigger_lock);
241 led_trigger_set(led_cdev, NULL);
242 up_write(&led_cdev->trigger_lock);
243}
244EXPORT_SYMBOL_GPL(led_trigger_remove);
245
246void led_trigger_set_default(struct led_classdev *led_cdev)
247{
248 struct led_trigger *trig;
249
250 if (!led_cdev->default_trigger)
251 return;
252
253 down_read(&triggers_list_lock);
254 down_write(&led_cdev->trigger_lock);
255 list_for_each_entry(trig, &trigger_list, next_trig) {
256 if (!strcmp(led_cdev->default_trigger, trig->name) &&
257 trigger_relevant(led_cdev, trig)) {
258 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
259 led_trigger_set(led_cdev, trig);
260 break;
261 }
262 }
263 up_write(&led_cdev->trigger_lock);
264 up_read(&triggers_list_lock);
265}
266EXPORT_SYMBOL_GPL(led_trigger_set_default);
267
268void led_trigger_rename_static(const char *name, struct led_trigger *trig)
269{
270 /* new name must be on a temporary string to prevent races */
271 BUG_ON(name == trig->name);
272
273 down_write(&triggers_list_lock);
274 /* this assumes that trig->name was originaly allocated to
275 * non constant storage */
276 strcpy((char *)trig->name, name);
277 up_write(&triggers_list_lock);
278}
279EXPORT_SYMBOL_GPL(led_trigger_rename_static);
280
281/* LED Trigger Interface */
282
283int led_trigger_register(struct led_trigger *trig)
284{
285 struct led_classdev *led_cdev;
286 struct led_trigger *_trig;
287
288 rwlock_init(&trig->leddev_list_lock);
289 INIT_LIST_HEAD(&trig->led_cdevs);
290
291 down_write(&triggers_list_lock);
292 /* Make sure the trigger's name isn't already in use */
293 list_for_each_entry(_trig, &trigger_list, next_trig) {
294 if (!strcmp(_trig->name, trig->name) &&
295 (trig->trigger_type == _trig->trigger_type ||
296 !trig->trigger_type || !_trig->trigger_type)) {
297 up_write(&triggers_list_lock);
298 return -EEXIST;
299 }
300 }
301 /* Add to the list of led triggers */
302 list_add_tail(&trig->next_trig, &trigger_list);
303 up_write(&triggers_list_lock);
304
305 /* Register with any LEDs that have this as a default trigger */
306 down_read(&leds_list_lock);
307 list_for_each_entry(led_cdev, &leds_list, node) {
308 down_write(&led_cdev->trigger_lock);
309 if (!led_cdev->trigger && led_cdev->default_trigger &&
310 !strcmp(led_cdev->default_trigger, trig->name) &&
311 trigger_relevant(led_cdev, trig)) {
312 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
313 led_trigger_set(led_cdev, trig);
314 }
315 up_write(&led_cdev->trigger_lock);
316 }
317 up_read(&leds_list_lock);
318
319 return 0;
320}
321EXPORT_SYMBOL_GPL(led_trigger_register);
322
323void led_trigger_unregister(struct led_trigger *trig)
324{
325 struct led_classdev *led_cdev;
326
327 if (list_empty_careful(&trig->next_trig))
328 return;
329
330 /* Remove from the list of led triggers */
331 down_write(&triggers_list_lock);
332 list_del_init(&trig->next_trig);
333 up_write(&triggers_list_lock);
334
335 /* Remove anyone actively using this trigger */
336 down_read(&leds_list_lock);
337 list_for_each_entry(led_cdev, &leds_list, node) {
338 down_write(&led_cdev->trigger_lock);
339 if (led_cdev->trigger == trig)
340 led_trigger_set(led_cdev, NULL);
341 up_write(&led_cdev->trigger_lock);
342 }
343 up_read(&leds_list_lock);
344}
345EXPORT_SYMBOL_GPL(led_trigger_unregister);
346
347static void devm_led_trigger_release(struct device *dev, void *res)
348{
349 led_trigger_unregister(*(struct led_trigger **)res);
350}
351
352int devm_led_trigger_register(struct device *dev,
353 struct led_trigger *trig)
354{
355 struct led_trigger **dr;
356 int rc;
357
358 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
359 GFP_KERNEL);
360 if (!dr)
361 return -ENOMEM;
362
363 *dr = trig;
364
365 rc = led_trigger_register(trig);
366 if (rc)
367 devres_free(dr);
368 else
369 devres_add(dev, dr);
370
371 return rc;
372}
373EXPORT_SYMBOL_GPL(devm_led_trigger_register);
374
375/* Simple LED Trigger Interface */
376
377void led_trigger_event(struct led_trigger *trig,
378 enum led_brightness brightness)
379{
380 struct led_classdev *led_cdev;
381
382 if (!trig)
383 return;
384
385 read_lock(&trig->leddev_list_lock);
386 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
387 led_set_brightness(led_cdev, brightness);
388 read_unlock(&trig->leddev_list_lock);
389}
390EXPORT_SYMBOL_GPL(led_trigger_event);
391
392static void led_trigger_blink_setup(struct led_trigger *trig,
393 unsigned long *delay_on,
394 unsigned long *delay_off,
395 int oneshot,
396 int invert)
397{
398 struct led_classdev *led_cdev;
399
400 if (!trig)
401 return;
402
403 read_lock(&trig->leddev_list_lock);
404 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
405 if (oneshot)
406 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
407 invert);
408 else
409 led_blink_set(led_cdev, delay_on, delay_off);
410 }
411 read_unlock(&trig->leddev_list_lock);
412}
413
414void led_trigger_blink(struct led_trigger *trig,
415 unsigned long *delay_on,
416 unsigned long *delay_off)
417{
418 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
419}
420EXPORT_SYMBOL_GPL(led_trigger_blink);
421
422void led_trigger_blink_oneshot(struct led_trigger *trig,
423 unsigned long *delay_on,
424 unsigned long *delay_off,
425 int invert)
426{
427 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
428}
429EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
430
431void led_trigger_register_simple(const char *name, struct led_trigger **tp)
432{
433 struct led_trigger *trig;
434 int err;
435
436 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
437
438 if (trig) {
439 trig->name = name;
440 err = led_trigger_register(trig);
441 if (err < 0) {
442 kfree(trig);
443 trig = NULL;
444 pr_warn("LED trigger %s failed to register (%d)\n",
445 name, err);
446 }
447 } else {
448 pr_warn("LED trigger %s failed to register (no memory)\n",
449 name);
450 }
451 *tp = trig;
452}
453EXPORT_SYMBOL_GPL(led_trigger_register_simple);
454
455void led_trigger_unregister_simple(struct led_trigger *trig)
456{
457 if (trig)
458 led_trigger_unregister(trig);
459 kfree(trig);
460}
461EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);