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1/*
2 * LED Triggers Core
3 *
4 * Copyright 2005-2007 Openedhand Ltd.
5 *
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
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/list.h>
18#include <linux/spinlock.h>
19#include <linux/device.h>
20#include <linux/sysdev.h>
21#include <linux/timer.h>
22#include <linux/rwsem.h>
23#include <linux/leds.h>
24#include <linux/slab.h>
25#include "leds.h"
26
27/*
28 * Nests outside led_cdev->trigger_lock
29 */
30static DECLARE_RWSEM(triggers_list_lock);
31static LIST_HEAD(trigger_list);
32
33 /* Used by LED Class */
34
35ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
36 const char *buf, size_t count)
37{
38 struct led_classdev *led_cdev = dev_get_drvdata(dev);
39 char trigger_name[TRIG_NAME_MAX];
40 struct led_trigger *trig;
41 size_t len;
42
43 trigger_name[sizeof(trigger_name) - 1] = '\0';
44 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
45 len = strlen(trigger_name);
46
47 if (len && trigger_name[len - 1] == '\n')
48 trigger_name[len - 1] = '\0';
49
50 if (!strcmp(trigger_name, "none")) {
51 led_trigger_remove(led_cdev);
52 return count;
53 }
54
55 down_read(&triggers_list_lock);
56 list_for_each_entry(trig, &trigger_list, next_trig) {
57 if (!strcmp(trigger_name, trig->name)) {
58 down_write(&led_cdev->trigger_lock);
59 led_trigger_set(led_cdev, trig);
60 up_write(&led_cdev->trigger_lock);
61
62 up_read(&triggers_list_lock);
63 return count;
64 }
65 }
66 up_read(&triggers_list_lock);
67
68 return -EINVAL;
69}
70EXPORT_SYMBOL_GPL(led_trigger_store);
71
72ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
73 char *buf)
74{
75 struct led_classdev *led_cdev = dev_get_drvdata(dev);
76 struct led_trigger *trig;
77 int len = 0;
78
79 down_read(&triggers_list_lock);
80 down_read(&led_cdev->trigger_lock);
81
82 if (!led_cdev->trigger)
83 len += sprintf(buf+len, "[none] ");
84 else
85 len += sprintf(buf+len, "none ");
86
87 list_for_each_entry(trig, &trigger_list, next_trig) {
88 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
89 trig->name))
90 len += sprintf(buf+len, "[%s] ", trig->name);
91 else
92 len += sprintf(buf+len, "%s ", trig->name);
93 }
94 up_read(&led_cdev->trigger_lock);
95 up_read(&triggers_list_lock);
96
97 len += sprintf(len+buf, "\n");
98 return len;
99}
100EXPORT_SYMBOL_GPL(led_trigger_show);
101
102/* Caller must ensure led_cdev->trigger_lock held */
103void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
104{
105 unsigned long flags;
106
107 /* Remove any existing trigger */
108 if (led_cdev->trigger) {
109 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
110 list_del(&led_cdev->trig_list);
111 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
112 flags);
113 if (led_cdev->trigger->deactivate)
114 led_cdev->trigger->deactivate(led_cdev);
115 led_cdev->trigger = NULL;
116 led_brightness_set(led_cdev, LED_OFF);
117 }
118 if (trigger) {
119 write_lock_irqsave(&trigger->leddev_list_lock, flags);
120 list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
121 write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
122 led_cdev->trigger = trigger;
123 if (trigger->activate)
124 trigger->activate(led_cdev);
125 }
126}
127EXPORT_SYMBOL_GPL(led_trigger_set);
128
129void led_trigger_remove(struct led_classdev *led_cdev)
130{
131 down_write(&led_cdev->trigger_lock);
132 led_trigger_set(led_cdev, NULL);
133 up_write(&led_cdev->trigger_lock);
134}
135EXPORT_SYMBOL_GPL(led_trigger_remove);
136
137void led_trigger_set_default(struct led_classdev *led_cdev)
138{
139 struct led_trigger *trig;
140
141 if (!led_cdev->default_trigger)
142 return;
143
144 down_read(&triggers_list_lock);
145 down_write(&led_cdev->trigger_lock);
146 list_for_each_entry(trig, &trigger_list, next_trig) {
147 if (!strcmp(led_cdev->default_trigger, trig->name))
148 led_trigger_set(led_cdev, trig);
149 }
150 up_write(&led_cdev->trigger_lock);
151 up_read(&triggers_list_lock);
152}
153EXPORT_SYMBOL_GPL(led_trigger_set_default);
154
155/* LED Trigger Interface */
156
157int led_trigger_register(struct led_trigger *trigger)
158{
159 struct led_classdev *led_cdev;
160 struct led_trigger *trig;
161
162 rwlock_init(&trigger->leddev_list_lock);
163 INIT_LIST_HEAD(&trigger->led_cdevs);
164
165 down_write(&triggers_list_lock);
166 /* Make sure the trigger's name isn't already in use */
167 list_for_each_entry(trig, &trigger_list, next_trig) {
168 if (!strcmp(trig->name, trigger->name)) {
169 up_write(&triggers_list_lock);
170 return -EEXIST;
171 }
172 }
173 /* Add to the list of led triggers */
174 list_add_tail(&trigger->next_trig, &trigger_list);
175 up_write(&triggers_list_lock);
176
177 /* Register with any LEDs that have this as a default trigger */
178 down_read(&leds_list_lock);
179 list_for_each_entry(led_cdev, &leds_list, node) {
180 down_write(&led_cdev->trigger_lock);
181 if (!led_cdev->trigger && led_cdev->default_trigger &&
182 !strcmp(led_cdev->default_trigger, trigger->name))
183 led_trigger_set(led_cdev, trigger);
184 up_write(&led_cdev->trigger_lock);
185 }
186 up_read(&leds_list_lock);
187
188 return 0;
189}
190EXPORT_SYMBOL_GPL(led_trigger_register);
191
192void led_trigger_unregister(struct led_trigger *trigger)
193{
194 struct led_classdev *led_cdev;
195
196 /* Remove from the list of led triggers */
197 down_write(&triggers_list_lock);
198 list_del(&trigger->next_trig);
199 up_write(&triggers_list_lock);
200
201 /* Remove anyone actively using this trigger */
202 down_read(&leds_list_lock);
203 list_for_each_entry(led_cdev, &leds_list, node) {
204 down_write(&led_cdev->trigger_lock);
205 if (led_cdev->trigger == trigger)
206 led_trigger_set(led_cdev, NULL);
207 up_write(&led_cdev->trigger_lock);
208 }
209 up_read(&leds_list_lock);
210}
211EXPORT_SYMBOL_GPL(led_trigger_unregister);
212
213/* Simple LED Tigger Interface */
214
215void led_trigger_event(struct led_trigger *trigger,
216 enum led_brightness brightness)
217{
218 struct list_head *entry;
219
220 if (!trigger)
221 return;
222
223 read_lock(&trigger->leddev_list_lock);
224 list_for_each(entry, &trigger->led_cdevs) {
225 struct led_classdev *led_cdev;
226
227 led_cdev = list_entry(entry, struct led_classdev, trig_list);
228 led_set_brightness(led_cdev, brightness);
229 }
230 read_unlock(&trigger->leddev_list_lock);
231}
232EXPORT_SYMBOL_GPL(led_trigger_event);
233
234void led_trigger_blink(struct led_trigger *trigger,
235 unsigned long *delay_on,
236 unsigned long *delay_off)
237{
238 struct list_head *entry;
239
240 if (!trigger)
241 return;
242
243 read_lock(&trigger->leddev_list_lock);
244 list_for_each(entry, &trigger->led_cdevs) {
245 struct led_classdev *led_cdev;
246
247 led_cdev = list_entry(entry, struct led_classdev, trig_list);
248 led_blink_set(led_cdev, delay_on, delay_off);
249 }
250 read_unlock(&trigger->leddev_list_lock);
251}
252EXPORT_SYMBOL_GPL(led_trigger_blink);
253
254void led_trigger_register_simple(const char *name, struct led_trigger **tp)
255{
256 struct led_trigger *trigger;
257 int err;
258
259 trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
260
261 if (trigger) {
262 trigger->name = name;
263 err = led_trigger_register(trigger);
264 if (err < 0)
265 printk(KERN_WARNING "LED trigger %s failed to register"
266 " (%d)\n", name, err);
267 } else
268 printk(KERN_WARNING "LED trigger %s failed to register"
269 " (no memory)\n", name);
270
271 *tp = trigger;
272}
273EXPORT_SYMBOL_GPL(led_trigger_register_simple);
274
275void led_trigger_unregister_simple(struct led_trigger *trigger)
276{
277 if (trigger)
278 led_trigger_unregister(trigger);
279 kfree(trigger);
280}
281EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
282
283MODULE_AUTHOR("Richard Purdie");
284MODULE_LICENSE("GPL");
285MODULE_DESCRIPTION("LED Triggers Core");
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 "leds.h"
20
21/*
22 * Nests outside led_cdev->trigger_lock
23 */
24static DECLARE_RWSEM(triggers_list_lock);
25LIST_HEAD(trigger_list);
26
27 /* Used by LED Class */
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 /* we come here only if buf matches no trigger */
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/* Caller must ensure led_cdev->trigger_lock held */
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 /* Remove any existing trigger */
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 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
171 list_del(&led_cdev->trig_list);
172 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags);
173 led_cdev->trigger = NULL;
174 led_cdev->trigger_data = NULL;
175 led_set_brightness(led_cdev, LED_OFF);
176 kfree(event);
177
178 return ret;
179}
180EXPORT_SYMBOL_GPL(led_trigger_set);
181
182void led_trigger_remove(struct led_classdev *led_cdev)
183{
184 down_write(&led_cdev->trigger_lock);
185 led_trigger_set(led_cdev, NULL);
186 up_write(&led_cdev->trigger_lock);
187}
188EXPORT_SYMBOL_GPL(led_trigger_remove);
189
190void led_trigger_set_default(struct led_classdev *led_cdev)
191{
192 struct led_trigger *trig;
193
194 if (!led_cdev->default_trigger)
195 return;
196
197 down_read(&triggers_list_lock);
198 down_write(&led_cdev->trigger_lock);
199 list_for_each_entry(trig, &trigger_list, next_trig) {
200 if (!strcmp(led_cdev->default_trigger, trig->name)) {
201 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
202 led_trigger_set(led_cdev, trig);
203 break;
204 }
205 }
206 up_write(&led_cdev->trigger_lock);
207 up_read(&triggers_list_lock);
208}
209EXPORT_SYMBOL_GPL(led_trigger_set_default);
210
211void led_trigger_rename_static(const char *name, struct led_trigger *trig)
212{
213 /* new name must be on a temporary string to prevent races */
214 BUG_ON(name == trig->name);
215
216 down_write(&triggers_list_lock);
217 /* this assumes that trig->name was originaly allocated to
218 * non constant storage */
219 strcpy((char *)trig->name, name);
220 up_write(&triggers_list_lock);
221}
222EXPORT_SYMBOL_GPL(led_trigger_rename_static);
223
224/* LED Trigger Interface */
225
226int led_trigger_register(struct led_trigger *trig)
227{
228 struct led_classdev *led_cdev;
229 struct led_trigger *_trig;
230
231 rwlock_init(&trig->leddev_list_lock);
232 INIT_LIST_HEAD(&trig->led_cdevs);
233
234 down_write(&triggers_list_lock);
235 /* Make sure the trigger's name isn't already in use */
236 list_for_each_entry(_trig, &trigger_list, next_trig) {
237 if (!strcmp(_trig->name, trig->name)) {
238 up_write(&triggers_list_lock);
239 return -EEXIST;
240 }
241 }
242 /* Add to the list of led triggers */
243 list_add_tail(&trig->next_trig, &trigger_list);
244 up_write(&triggers_list_lock);
245
246 /* Register with any LEDs that have this as a default trigger */
247 down_read(&leds_list_lock);
248 list_for_each_entry(led_cdev, &leds_list, node) {
249 down_write(&led_cdev->trigger_lock);
250 if (!led_cdev->trigger && led_cdev->default_trigger &&
251 !strcmp(led_cdev->default_trigger, trig->name)) {
252 led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
253 led_trigger_set(led_cdev, trig);
254 }
255 up_write(&led_cdev->trigger_lock);
256 }
257 up_read(&leds_list_lock);
258
259 return 0;
260}
261EXPORT_SYMBOL_GPL(led_trigger_register);
262
263void led_trigger_unregister(struct led_trigger *trig)
264{
265 struct led_classdev *led_cdev;
266
267 if (list_empty_careful(&trig->next_trig))
268 return;
269
270 /* Remove from the list of led triggers */
271 down_write(&triggers_list_lock);
272 list_del_init(&trig->next_trig);
273 up_write(&triggers_list_lock);
274
275 /* Remove anyone actively using this trigger */
276 down_read(&leds_list_lock);
277 list_for_each_entry(led_cdev, &leds_list, node) {
278 down_write(&led_cdev->trigger_lock);
279 if (led_cdev->trigger == trig)
280 led_trigger_set(led_cdev, NULL);
281 up_write(&led_cdev->trigger_lock);
282 }
283 up_read(&leds_list_lock);
284}
285EXPORT_SYMBOL_GPL(led_trigger_unregister);
286
287static void devm_led_trigger_release(struct device *dev, void *res)
288{
289 led_trigger_unregister(*(struct led_trigger **)res);
290}
291
292int devm_led_trigger_register(struct device *dev,
293 struct led_trigger *trig)
294{
295 struct led_trigger **dr;
296 int rc;
297
298 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
299 GFP_KERNEL);
300 if (!dr)
301 return -ENOMEM;
302
303 *dr = trig;
304
305 rc = led_trigger_register(trig);
306 if (rc)
307 devres_free(dr);
308 else
309 devres_add(dev, dr);
310
311 return rc;
312}
313EXPORT_SYMBOL_GPL(devm_led_trigger_register);
314
315/* Simple LED Tigger Interface */
316
317void led_trigger_event(struct led_trigger *trig,
318 enum led_brightness brightness)
319{
320 struct led_classdev *led_cdev;
321
322 if (!trig)
323 return;
324
325 read_lock(&trig->leddev_list_lock);
326 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
327 led_set_brightness(led_cdev, brightness);
328 read_unlock(&trig->leddev_list_lock);
329}
330EXPORT_SYMBOL_GPL(led_trigger_event);
331
332static void led_trigger_blink_setup(struct led_trigger *trig,
333 unsigned long *delay_on,
334 unsigned long *delay_off,
335 int oneshot,
336 int invert)
337{
338 struct led_classdev *led_cdev;
339
340 if (!trig)
341 return;
342
343 read_lock(&trig->leddev_list_lock);
344 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
345 if (oneshot)
346 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
347 invert);
348 else
349 led_blink_set(led_cdev, delay_on, delay_off);
350 }
351 read_unlock(&trig->leddev_list_lock);
352}
353
354void led_trigger_blink(struct led_trigger *trig,
355 unsigned long *delay_on,
356 unsigned long *delay_off)
357{
358 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
359}
360EXPORT_SYMBOL_GPL(led_trigger_blink);
361
362void led_trigger_blink_oneshot(struct led_trigger *trig,
363 unsigned long *delay_on,
364 unsigned long *delay_off,
365 int invert)
366{
367 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
368}
369EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
370
371void led_trigger_register_simple(const char *name, struct led_trigger **tp)
372{
373 struct led_trigger *trig;
374 int err;
375
376 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
377
378 if (trig) {
379 trig->name = name;
380 err = led_trigger_register(trig);
381 if (err < 0) {
382 kfree(trig);
383 trig = NULL;
384 pr_warn("LED trigger %s failed to register (%d)\n",
385 name, err);
386 }
387 } else {
388 pr_warn("LED trigger %s failed to register (no memory)\n",
389 name);
390 }
391 *tp = trig;
392}
393EXPORT_SYMBOL_GPL(led_trigger_register_simple);
394
395void led_trigger_unregister_simple(struct led_trigger *trig)
396{
397 if (trig)
398 led_trigger_unregister(trig);
399 kfree(trig);
400}
401EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);