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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
24
25static DECLARE_RWSEM(triggers_list_lock);
26LIST_HEAD(trigger_list);
27
28
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
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
121
122
123
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
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
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
271 BUG_ON(name == trig->name);
272
273 down_write(&triggers_list_lock);
274
275
276 strcpy((char *)trig->name, name);
277 up_write(&triggers_list_lock);
278}
279EXPORT_SYMBOL_GPL(led_trigger_rename_static);
280
281
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
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
302 list_add_tail(&trig->next_trig, &trigger_list);
303 up_write(&triggers_list_lock);
304
305
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
331 down_write(&triggers_list_lock);
332 list_del_init(&trig->next_trig);
333 up_write(&triggers_list_lock);
334
335
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
376
377void led_trigger_event(struct led_trigger *trig,
378 enum led_brightness brightness)
379{
380 struct led_classdev *led_cdev;
381 unsigned long flags;
382
383 if (!trig)
384 return;
385
386 read_lock_irqsave(&trig->leddev_list_lock, flags);
387 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
388 led_set_brightness(led_cdev, brightness);
389 read_unlock_irqrestore(&trig->leddev_list_lock, flags);
390}
391EXPORT_SYMBOL_GPL(led_trigger_event);
392
393static void led_trigger_blink_setup(struct led_trigger *trig,
394 unsigned long *delay_on,
395 unsigned long *delay_off,
396 int oneshot,
397 int invert)
398{
399 struct led_classdev *led_cdev;
400 unsigned long flags;
401
402 if (!trig)
403 return;
404
405 read_lock_irqsave(&trig->leddev_list_lock, flags);
406 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
407 if (oneshot)
408 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
409 invert);
410 else
411 led_blink_set(led_cdev, delay_on, delay_off);
412 }
413 read_unlock_irqrestore(&trig->leddev_list_lock, flags);
414}
415
416void led_trigger_blink(struct led_trigger *trig,
417 unsigned long *delay_on,
418 unsigned long *delay_off)
419{
420 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
421}
422EXPORT_SYMBOL_GPL(led_trigger_blink);
423
424void led_trigger_blink_oneshot(struct led_trigger *trig,
425 unsigned long *delay_on,
426 unsigned long *delay_off,
427 int invert)
428{
429 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
430}
431EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
432
433void led_trigger_register_simple(const char *name, struct led_trigger **tp)
434{
435 struct led_trigger *trig;
436 int err;
437
438 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
439
440 if (trig) {
441 trig->name = name;
442 err = led_trigger_register(trig);
443 if (err < 0) {
444 kfree(trig);
445 trig = NULL;
446 pr_warn("LED trigger %s failed to register (%d)\n",
447 name, err);
448 }
449 } else {
450 pr_warn("LED trigger %s failed to register (no memory)\n",
451 name);
452 }
453 *tp = trig;
454}
455EXPORT_SYMBOL_GPL(led_trigger_register_simple);
456
457void led_trigger_unregister_simple(struct led_trigger *trig)
458{
459 if (trig)
460 led_trigger_unregister(trig);
461 kfree(trig);
462}
463EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
464
