1
2
3
4
5
6
7
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 "leds.h"
20
21
22
23
24static DECLARE_RWSEM(triggers_list_lock);
25LIST_HEAD(trigger_list);
26
27
28
29ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
30 const char *buf, size_t count)
31{
32 struct led_classdev *led_cdev = dev_get_drvdata(dev);
33 struct led_trigger *trig;
34 int ret = count;
35
36 mutex_lock(&led_cdev->led_access);
37
38 if (led_sysfs_is_disabled(led_cdev)) {
39 ret = -EBUSY;
40 goto unlock;
41 }
42
43 if (sysfs_streq(buf, "none")) {
44 led_trigger_remove(led_cdev);
45 goto unlock;
46 }
47
48 down_read(&triggers_list_lock);
49 list_for_each_entry(trig, &trigger_list, next_trig) {
50 if (sysfs_streq(buf, trig->name)) {
51 down_write(&led_cdev->trigger_lock);
52 led_trigger_set(led_cdev, trig);
53 up_write(&led_cdev->trigger_lock);
54
55 up_read(&triggers_list_lock);
56 goto unlock;
57 }
58 }
59
60 ret = -EINVAL;
61 up_read(&triggers_list_lock);
62
63unlock:
64 mutex_unlock(&led_cdev->led_access);
65 return ret;
66}
67EXPORT_SYMBOL_GPL(led_trigger_store);
68
69ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
70 char *buf)
71{
72 struct led_classdev *led_cdev = dev_get_drvdata(dev);
73 struct led_trigger *trig;
74 int len = 0;
75
76 down_read(&triggers_list_lock);
77 down_read(&led_cdev->trigger_lock);
78
79 if (!led_cdev->trigger)
80 len += scnprintf(buf+len, PAGE_SIZE - len, "[none] ");
81 else
82 len += scnprintf(buf+len, PAGE_SIZE - len, "none ");
83
84 list_for_each_entry(trig, &trigger_list, next_trig) {
85 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
86 trig->name))
87 len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ",
88 trig->name);
89 else
90 len += scnprintf(buf+len, PAGE_SIZE - len, "%s ",
91 trig->name);
92 }
93 up_read(&led_cdev->trigger_lock);
94 up_read(&triggers_list_lock);
95
96 len += scnprintf(len+buf, PAGE_SIZE - len, "\n");
97 return len;
98}
99EXPORT_SYMBOL_GPL(led_trigger_show);
100
101
102int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
103{
104 unsigned long flags;
105 char *event = NULL;
106 char *envp[2];
107 const char *name;
108 int ret;
109
110 if (!led_cdev->trigger && !trig)
111 return 0;
112
113 name = trig ? trig->name : "none";
114 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
115
116
117 if (led_cdev->trigger) {
118 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
119 list_del(&led_cdev->trig_list);
120 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
121 flags);
122 cancel_work_sync(&led_cdev->set_brightness_work);
123 led_stop_software_blink(led_cdev);
124 if (led_cdev->trigger->deactivate)
125 led_cdev->trigger->deactivate(led_cdev);
126 device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
127 led_cdev->trigger = NULL;
128 led_cdev->trigger_data = NULL;
129 led_cdev->activated = false;
130 led_set_brightness(led_cdev, LED_OFF);
131 }
132 if (trig) {
133 write_lock_irqsave(&trig->leddev_list_lock, flags);
134 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
135 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
136 led_cdev->trigger = trig;
137
138 if (trig->activate)
139 ret = trig->activate(led_cdev);
140 else
141 ret = 0;
142
143 if (ret)
144 goto err_activate;
145
146 ret = device_add_groups(led_cdev->dev, trig->groups);
147 if (ret) {
148 dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
149 goto err_add_groups;
150 }
151 }
152
153 if (event) {
154 envp[0] = event;
155 envp[1] = NULL;
156 if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
157 dev_err(led_cdev->dev,
158 "%s: Error sending uevent\n", __func__);
159 kfree(event);
160 }
161
162 return 0;
163
164err_add_groups:
165
166 if (trig->deactivate)
167 trig->deactivate(led_cdev);
168err_activate:
169
170 led_cdev->trigger = NULL;
171 led_cdev->trigger_data = NULL;
172 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
173 list_del(&led_cdev->trig_list);
174 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
175 led_set_brightness(led_cdev, LED_OFF);
176
177 return ret;
178}
179EXPORT_SYMBOL_GPL(led_trigger_set);
180
181void led_trigger_remove(struct led_classdev *led_cdev)
182{
183 down_write(&led_cdev->trigger_lock);
184 led_trigger_set(led_cdev, NULL);
185 up_write(&led_cdev->trigger_lock);
186}
187EXPORT_SYMBOL_GPL(led_trigger_remove);
188
189void led_trigger_set_default(struct led_classdev *led_cdev)
190{
191 struct led_trigger *trig;
192
193 if (!led_cdev->default_trigger)
194 return;
195
196 down_read(&triggers_list_lock);
197 down_write(&led_cdev->trigger_lock);
198 list_for_each_entry(trig, &trigger_list, next_trig) {
199 if (!strcmp(led_cdev->default_trigger, trig->name)) {
200 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
201 led_trigger_set(led_cdev, trig);
202 break;
203 }
204 }
205 up_write(&led_cdev->trigger_lock);
206 up_read(&triggers_list_lock);
207}
208EXPORT_SYMBOL_GPL(led_trigger_set_default);
209
210void led_trigger_rename_static(const char *name, struct led_trigger *trig)
211{
212
213 BUG_ON(name == trig->name);
214
215 down_write(&triggers_list_lock);
216
217
218 strcpy((char *)trig->name, name);
219 up_write(&triggers_list_lock);
220}
221EXPORT_SYMBOL_GPL(led_trigger_rename_static);
222
223
224
225int led_trigger_register(struct led_trigger *trig)
226{
227 struct led_classdev *led_cdev;
228 struct led_trigger *_trig;
229
230 rwlock_init(&trig->leddev_list_lock);
231 INIT_LIST_HEAD(&trig->led_cdevs);
232
233 down_write(&triggers_list_lock);
234
235 list_for_each_entry(_trig, &trigger_list, next_trig) {
236 if (!strcmp(_trig->name, trig->name)) {
237 up_write(&triggers_list_lock);
238 return -EEXIST;
239 }
240 }
241
242 list_add_tail(&trig->next_trig, &trigger_list);
243 up_write(&triggers_list_lock);
244
245
246 down_read(&leds_list_lock);
247 list_for_each_entry(led_cdev, &leds_list, node) {
248 down_write(&led_cdev->trigger_lock);
249 if (!led_cdev->trigger && led_cdev->default_trigger &&
250 !strcmp(led_cdev->default_trigger, trig->name)) {
251 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
252 led_trigger_set(led_cdev, trig);
253 }
254 up_write(&led_cdev->trigger_lock);
255 }
256 up_read(&leds_list_lock);
257
258 return 0;
259}
260EXPORT_SYMBOL_GPL(led_trigger_register);
261
262void led_trigger_unregister(struct led_trigger *trig)
263{
264 struct led_classdev *led_cdev;
265
266 if (list_empty_careful(&trig->next_trig))
267 return;
268
269
270 down_write(&triggers_list_lock);
271 list_del_init(&trig->next_trig);
272 up_write(&triggers_list_lock);
273
274
275 down_read(&leds_list_lock);
276 list_for_each_entry(led_cdev, &leds_list, node) {
277 down_write(&led_cdev->trigger_lock);
278 if (led_cdev->trigger == trig)
279 led_trigger_set(led_cdev, NULL);
280 up_write(&led_cdev->trigger_lock);
281 }
282 up_read(&leds_list_lock);
283}
284EXPORT_SYMBOL_GPL(led_trigger_unregister);
285
286static void devm_led_trigger_release(struct device *dev, void *res)
287{
288 led_trigger_unregister(*(struct led_trigger **)res);
289}
290
291int devm_led_trigger_register(struct device *dev,
292 struct led_trigger *trig)
293{
294 struct led_trigger **dr;
295 int rc;
296
297 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
298 GFP_KERNEL);
299 if (!dr)
300 return -ENOMEM;
301
302 *dr = trig;
303
304 rc = led_trigger_register(trig);
305 if (rc)
306 devres_free(dr);
307 else
308 devres_add(dev, dr);
309
310 return rc;
311}
312EXPORT_SYMBOL_GPL(devm_led_trigger_register);
313
314
315
316void led_trigger_event(struct led_trigger *trig,
317 enum led_brightness brightness)
318{
319 struct led_classdev *led_cdev;
320
321 if (!trig)
322 return;
323
324 read_lock(&trig->leddev_list_lock);
325 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
326 led_set_brightness(led_cdev, brightness);
327 read_unlock(&trig->leddev_list_lock);
328}
329EXPORT_SYMBOL_GPL(led_trigger_event);
330
331static void led_trigger_blink_setup(struct led_trigger *trig,
332 unsigned long *delay_on,
333 unsigned long *delay_off,
334 int oneshot,
335 int invert)
336{
337 struct led_classdev *led_cdev;
338
339 if (!trig)
340 return;
341
342 read_lock(&trig->leddev_list_lock);
343 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
344 if (oneshot)
345 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
346 invert);
347 else
348 led_blink_set(led_cdev, delay_on, delay_off);
349 }
350 read_unlock(&trig->leddev_list_lock);
351}
352
353void led_trigger_blink(struct led_trigger *trig,
354 unsigned long *delay_on,
355 unsigned long *delay_off)
356{
357 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
358}
359EXPORT_SYMBOL_GPL(led_trigger_blink);
360
361void led_trigger_blink_oneshot(struct led_trigger *trig,
362 unsigned long *delay_on,
363 unsigned long *delay_off,
364 int invert)
365{
366 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
367}
368EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
369
370void led_trigger_register_simple(const char *name, struct led_trigger **tp)
371{
372 struct led_trigger *trig;
373 int err;
374
375 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
376
377 if (trig) {
378 trig->name = name;
379 err = led_trigger_register(trig);
380 if (err < 0) {
381 kfree(trig);
382 trig = NULL;
383 pr_warn("LED trigger %s failed to register (%d)\n",
384 name, err);
385 }
386 } else {
387 pr_warn("LED trigger %s failed to register (no memory)\n",
388 name);
389 }
390 *tp = trig;
391}
392EXPORT_SYMBOL_GPL(led_trigger_register_simple);
393
394void led_trigger_unregister_simple(struct led_trigger *trig)
395{
396 if (trig)
397 led_trigger_unregister(trig);
398 kfree(trig);
399}
400EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
401
