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v6.8
  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_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
189		led_set_brightness(led_cdev, LED_OFF);
190	}
191	if (trig) {
192		spin_lock(&trig->leddev_list_lock);
193		list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);
194		spin_unlock(&trig->leddev_list_lock);
195		led_cdev->trigger = trig;
196
197		if (trig->activate)
198			ret = trig->activate(led_cdev);
199		else
200			ret = 0;
201
202		if (ret)
203			goto err_activate;
204
205		ret = device_add_groups(led_cdev->dev, trig->groups);
206		if (ret) {
207			dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
208			goto err_add_groups;
209		}
210	}
211
212	if (event) {
213		envp[0] = event;
214		envp[1] = NULL;
215		if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
216			dev_err(led_cdev->dev,
217				"%s: Error sending uevent\n", __func__);
218		kfree(event);
219	}
220
221	return 0;
222
223err_add_groups:
224
225	if (trig->deactivate)
226		trig->deactivate(led_cdev);
227err_activate:
228
229	spin_lock(&led_cdev->trigger->leddev_list_lock);
230	list_del_rcu(&led_cdev->trig_list);
231	spin_unlock(&led_cdev->trigger->leddev_list_lock);
232	synchronize_rcu();
233	led_cdev->trigger = NULL;
234	led_cdev->trigger_data = NULL;
235	led_set_brightness(led_cdev, LED_OFF);
236	kfree(event);
237
238	return ret;
239}
240EXPORT_SYMBOL_GPL(led_trigger_set);
241
242void led_trigger_remove(struct led_classdev *led_cdev)
243{
244	down_write(&led_cdev->trigger_lock);
245	led_trigger_set(led_cdev, NULL);
246	up_write(&led_cdev->trigger_lock);
247}
248EXPORT_SYMBOL_GPL(led_trigger_remove);
249
250void led_trigger_set_default(struct led_classdev *led_cdev)
251{
252	struct led_trigger *trig;
253
254	if (!led_cdev->default_trigger)
255		return;
256
257	down_read(&triggers_list_lock);
258	down_write(&led_cdev->trigger_lock);
259	list_for_each_entry(trig, &trigger_list, next_trig) {
260		if (!strcmp(led_cdev->default_trigger, trig->name) &&
261		    trigger_relevant(led_cdev, trig)) {
262			led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
263			led_trigger_set(led_cdev, trig);
264			break;
265		}
266	}
267	up_write(&led_cdev->trigger_lock);
268	up_read(&triggers_list_lock);
269}
270EXPORT_SYMBOL_GPL(led_trigger_set_default);
271
 
 
 
 
 
 
 
 
 
 
 
 
 
272/* LED Trigger Interface */
273
274int led_trigger_register(struct led_trigger *trig)
275{
276	struct led_classdev *led_cdev;
277	struct led_trigger *_trig;
278
279	spin_lock_init(&trig->leddev_list_lock);
280	INIT_LIST_HEAD(&trig->led_cdevs);
281
282	down_write(&triggers_list_lock);
283	/* Make sure the trigger's name isn't already in use */
284	list_for_each_entry(_trig, &trigger_list, next_trig) {
285		if (!strcmp(_trig->name, trig->name) &&
286		    (trig->trigger_type == _trig->trigger_type ||
287		     !trig->trigger_type || !_trig->trigger_type)) {
288			up_write(&triggers_list_lock);
289			return -EEXIST;
290		}
291	}
292	/* Add to the list of led triggers */
293	list_add_tail(&trig->next_trig, &trigger_list);
294	up_write(&triggers_list_lock);
295
296	/* Register with any LEDs that have this as a default trigger */
297	down_read(&leds_list_lock);
298	list_for_each_entry(led_cdev, &leds_list, node) {
299		down_write(&led_cdev->trigger_lock);
300		if (!led_cdev->trigger && led_cdev->default_trigger &&
301		    !strcmp(led_cdev->default_trigger, trig->name) &&
302		    trigger_relevant(led_cdev, trig)) {
303			led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
304			led_trigger_set(led_cdev, trig);
305		}
306		up_write(&led_cdev->trigger_lock);
307	}
308	up_read(&leds_list_lock);
309
310	return 0;
311}
312EXPORT_SYMBOL_GPL(led_trigger_register);
313
314void led_trigger_unregister(struct led_trigger *trig)
315{
316	struct led_classdev *led_cdev;
317
318	if (list_empty_careful(&trig->next_trig))
319		return;
320
321	/* Remove from the list of led triggers */
322	down_write(&triggers_list_lock);
323	list_del_init(&trig->next_trig);
324	up_write(&triggers_list_lock);
325
326	/* Remove anyone actively using this trigger */
327	down_read(&leds_list_lock);
328	list_for_each_entry(led_cdev, &leds_list, node) {
329		down_write(&led_cdev->trigger_lock);
330		if (led_cdev->trigger == trig)
331			led_trigger_set(led_cdev, NULL);
332		up_write(&led_cdev->trigger_lock);
333	}
334	up_read(&leds_list_lock);
335}
336EXPORT_SYMBOL_GPL(led_trigger_unregister);
337
338static void devm_led_trigger_release(struct device *dev, void *res)
339{
340	led_trigger_unregister(*(struct led_trigger **)res);
341}
342
343int devm_led_trigger_register(struct device *dev,
344			      struct led_trigger *trig)
345{
346	struct led_trigger **dr;
347	int rc;
348
349	dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
350			  GFP_KERNEL);
351	if (!dr)
352		return -ENOMEM;
353
354	*dr = trig;
355
356	rc = led_trigger_register(trig);
357	if (rc)
358		devres_free(dr);
359	else
360		devres_add(dev, dr);
361
362	return rc;
363}
364EXPORT_SYMBOL_GPL(devm_led_trigger_register);
365
366/* Simple LED Trigger Interface */
367
368void led_trigger_event(struct led_trigger *trig,
369			enum led_brightness brightness)
370{
371	struct led_classdev *led_cdev;
372
373	if (!trig)
374		return;
375
376	rcu_read_lock();
377	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list)
378		led_set_brightness(led_cdev, brightness);
379	rcu_read_unlock();
380}
381EXPORT_SYMBOL_GPL(led_trigger_event);
382
383static void led_trigger_blink_setup(struct led_trigger *trig,
384			     unsigned long delay_on,
385			     unsigned long delay_off,
386			     int oneshot,
387			     int invert)
388{
389	struct led_classdev *led_cdev;
390
391	if (!trig)
392		return;
393
394	rcu_read_lock();
395	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
396		if (oneshot)
397			led_blink_set_oneshot(led_cdev, &delay_on, &delay_off,
398					      invert);
399		else
400			led_blink_set_nosleep(led_cdev, delay_on, delay_off);
401	}
402	rcu_read_unlock();
403}
404
405void led_trigger_blink(struct led_trigger *trig,
406		       unsigned long delay_on,
407		       unsigned long delay_off)
408{
409	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
410}
411EXPORT_SYMBOL_GPL(led_trigger_blink);
412
413void led_trigger_blink_oneshot(struct led_trigger *trig,
414			       unsigned long delay_on,
415			       unsigned long delay_off,
416			       int invert)
417{
418	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
419}
420EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
421
422void led_trigger_register_simple(const char *name, struct led_trigger **tp)
423{
424	struct led_trigger *trig;
425	int err;
426
427	trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
428
429	if (trig) {
430		trig->name = name;
431		err = led_trigger_register(trig);
432		if (err < 0) {
433			kfree(trig);
434			trig = NULL;
435			pr_warn("LED trigger %s failed to register (%d)\n",
436				name, err);
437		}
438	} else {
439		pr_warn("LED trigger %s failed to register (no memory)\n",
440			name);
441	}
442	*tp = trig;
443}
444EXPORT_SYMBOL_GPL(led_trigger_register_simple);
445
446void led_trigger_unregister_simple(struct led_trigger *trig)
447{
448	if (trig)
449		led_trigger_unregister(trig);
450	kfree(trig);
451}
452EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
v4.6
 
  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/list.h>
 17#include <linux/spinlock.h>
 18#include <linux/device.h>
 19#include <linux/timer.h>
 20#include <linux/rwsem.h>
 21#include <linux/leds.h>
 22#include <linux/slab.h>
 
 23#include "leds.h"
 24
 25/*
 26 * Nests outside led_cdev->trigger_lock
 27 */
 28static DECLARE_RWSEM(triggers_list_lock);
 29static LIST_HEAD(trigger_list);
 30
 31 /* Used by LED Class */
 32
 33ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 34		const char *buf, size_t count)
 
 
 
 
 
 
 
 35{
 
 36	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 37	struct led_trigger *trig;
 38	int ret = count;
 39
 40	mutex_lock(&led_cdev->led_access);
 41
 42	if (led_sysfs_is_disabled(led_cdev)) {
 43		ret = -EBUSY;
 44		goto unlock;
 45	}
 46
 47	if (sysfs_streq(buf, "none")) {
 48		led_trigger_remove(led_cdev);
 49		goto unlock;
 50	}
 51
 52	down_read(&triggers_list_lock);
 53	list_for_each_entry(trig, &trigger_list, next_trig) {
 54		if (sysfs_streq(buf, trig->name)) {
 55			down_write(&led_cdev->trigger_lock);
 56			led_trigger_set(led_cdev, trig);
 57			up_write(&led_cdev->trigger_lock);
 58
 59			up_read(&triggers_list_lock);
 60			goto unlock;
 61		}
 62	}
 
 
 63	up_read(&triggers_list_lock);
 64
 65unlock:
 66	mutex_unlock(&led_cdev->led_access);
 67	return ret;
 68}
 69EXPORT_SYMBOL_GPL(led_trigger_store);
 70
 71ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 72		char *buf)
 73{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 74	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 75	struct led_trigger *trig;
 76	int len = 0;
 77
 78	down_read(&triggers_list_lock);
 79	down_read(&led_cdev->trigger_lock);
 80
 81	if (!led_cdev->trigger)
 82		len += sprintf(buf+len, "[none] ");
 83	else
 84		len += sprintf(buf+len, "none ");
 
 
 
 
 85
 86	list_for_each_entry(trig, &trigger_list, next_trig) {
 87		if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
 88							trig->name))
 89			len += sprintf(buf+len, "[%s] ", trig->name);
 90		else
 91			len += sprintf(buf+len, "%s ", trig->name);
 92	}
 93	up_read(&led_cdev->trigger_lock);
 94	up_read(&triggers_list_lock);
 95
 96	len += sprintf(len+buf, "\n");
 
 
 
 97	return len;
 98}
 99EXPORT_SYMBOL_GPL(led_trigger_show);
100
101/* Caller must ensure led_cdev->trigger_lock held */
102void 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
109	name = trig ? trig->name : "none";
110	event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
111
112	/* Remove any existing trigger */
113	if (led_cdev->trigger) {
114		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
115		list_del(&led_cdev->trig_list);
116		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
117			flags);
 
 
 
118		cancel_work_sync(&led_cdev->set_brightness_work);
119		led_stop_software_blink(led_cdev);
120		if (led_cdev->trigger->deactivate)
121			led_cdev->trigger->deactivate(led_cdev);
 
122		led_cdev->trigger = NULL;
 
 
 
123		led_set_brightness(led_cdev, LED_OFF);
124	}
125	if (trig) {
126		write_lock_irqsave(&trig->leddev_list_lock, flags);
127		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
128		write_unlock_irqrestore(&trig->leddev_list_lock, flags);
129		led_cdev->trigger = trig;
 
130		if (trig->activate)
131			trig->activate(led_cdev);
 
 
 
 
 
 
 
 
 
 
 
132	}
133
134	if (event) {
135		envp[0] = event;
136		envp[1] = NULL;
137		kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
 
 
138		kfree(event);
139	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
140}
141EXPORT_SYMBOL_GPL(led_trigger_set);
142
143void led_trigger_remove(struct led_classdev *led_cdev)
144{
145	down_write(&led_cdev->trigger_lock);
146	led_trigger_set(led_cdev, NULL);
147	up_write(&led_cdev->trigger_lock);
148}
149EXPORT_SYMBOL_GPL(led_trigger_remove);
150
151void led_trigger_set_default(struct led_classdev *led_cdev)
152{
153	struct led_trigger *trig;
154
155	if (!led_cdev->default_trigger)
156		return;
157
158	down_read(&triggers_list_lock);
159	down_write(&led_cdev->trigger_lock);
160	list_for_each_entry(trig, &trigger_list, next_trig) {
161		if (!strcmp(led_cdev->default_trigger, trig->name))
 
 
162			led_trigger_set(led_cdev, trig);
 
 
163	}
164	up_write(&led_cdev->trigger_lock);
165	up_read(&triggers_list_lock);
166}
167EXPORT_SYMBOL_GPL(led_trigger_set_default);
168
169void led_trigger_rename_static(const char *name, struct led_trigger *trig)
170{
171	/* new name must be on a temporary string to prevent races */
172	BUG_ON(name == trig->name);
173
174	down_write(&triggers_list_lock);
175	/* this assumes that trig->name was originaly allocated to
176	 * non constant storage */
177	strcpy((char *)trig->name, name);
178	up_write(&triggers_list_lock);
179}
180EXPORT_SYMBOL_GPL(led_trigger_rename_static);
181
182/* LED Trigger Interface */
183
184int led_trigger_register(struct led_trigger *trig)
185{
186	struct led_classdev *led_cdev;
187	struct led_trigger *_trig;
188
189	rwlock_init(&trig->leddev_list_lock);
190	INIT_LIST_HEAD(&trig->led_cdevs);
191
192	down_write(&triggers_list_lock);
193	/* Make sure the trigger's name isn't already in use */
194	list_for_each_entry(_trig, &trigger_list, next_trig) {
195		if (!strcmp(_trig->name, trig->name)) {
 
 
196			up_write(&triggers_list_lock);
197			return -EEXIST;
198		}
199	}
200	/* Add to the list of led triggers */
201	list_add_tail(&trig->next_trig, &trigger_list);
202	up_write(&triggers_list_lock);
203
204	/* Register with any LEDs that have this as a default trigger */
205	down_read(&leds_list_lock);
206	list_for_each_entry(led_cdev, &leds_list, node) {
207		down_write(&led_cdev->trigger_lock);
208		if (!led_cdev->trigger && led_cdev->default_trigger &&
209			    !strcmp(led_cdev->default_trigger, trig->name))
 
 
210			led_trigger_set(led_cdev, trig);
 
211		up_write(&led_cdev->trigger_lock);
212	}
213	up_read(&leds_list_lock);
214
215	return 0;
216}
217EXPORT_SYMBOL_GPL(led_trigger_register);
218
219void led_trigger_unregister(struct led_trigger *trig)
220{
221	struct led_classdev *led_cdev;
222
223	if (list_empty_careful(&trig->next_trig))
224		return;
225
226	/* Remove from the list of led triggers */
227	down_write(&triggers_list_lock);
228	list_del_init(&trig->next_trig);
229	up_write(&triggers_list_lock);
230
231	/* Remove anyone actively using this trigger */
232	down_read(&leds_list_lock);
233	list_for_each_entry(led_cdev, &leds_list, node) {
234		down_write(&led_cdev->trigger_lock);
235		if (led_cdev->trigger == trig)
236			led_trigger_set(led_cdev, NULL);
237		up_write(&led_cdev->trigger_lock);
238	}
239	up_read(&leds_list_lock);
240}
241EXPORT_SYMBOL_GPL(led_trigger_unregister);
242
243static void devm_led_trigger_release(struct device *dev, void *res)
244{
245	led_trigger_unregister(*(struct led_trigger **)res);
246}
247
248int devm_led_trigger_register(struct device *dev,
249			      struct led_trigger *trig)
250{
251	struct led_trigger **dr;
252	int rc;
253
254	dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
255			  GFP_KERNEL);
256	if (!dr)
257		return -ENOMEM;
258
259	*dr = trig;
260
261	rc = led_trigger_register(trig);
262	if (rc)
263		devres_free(dr);
264	else
265		devres_add(dev, dr);
266
267	return rc;
268}
269EXPORT_SYMBOL_GPL(devm_led_trigger_register);
270
271/* Simple LED Tigger Interface */
272
273void led_trigger_event(struct led_trigger *trig,
274			enum led_brightness brightness)
275{
276	struct led_classdev *led_cdev;
277
278	if (!trig)
279		return;
280
281	read_lock(&trig->leddev_list_lock);
282	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
283		led_set_brightness(led_cdev, brightness);
284	read_unlock(&trig->leddev_list_lock);
285}
286EXPORT_SYMBOL_GPL(led_trigger_event);
287
288static void led_trigger_blink_setup(struct led_trigger *trig,
289			     unsigned long *delay_on,
290			     unsigned long *delay_off,
291			     int oneshot,
292			     int invert)
293{
294	struct led_classdev *led_cdev;
295
296	if (!trig)
297		return;
298
299	read_lock(&trig->leddev_list_lock);
300	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
301		if (oneshot)
302			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
303					      invert);
304		else
305			led_blink_set(led_cdev, delay_on, delay_off);
306	}
307	read_unlock(&trig->leddev_list_lock);
308}
309
310void led_trigger_blink(struct led_trigger *trig,
311		       unsigned long *delay_on,
312		       unsigned long *delay_off)
313{
314	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
315}
316EXPORT_SYMBOL_GPL(led_trigger_blink);
317
318void led_trigger_blink_oneshot(struct led_trigger *trig,
319			       unsigned long *delay_on,
320			       unsigned long *delay_off,
321			       int invert)
322{
323	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
324}
325EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
326
327void led_trigger_register_simple(const char *name, struct led_trigger **tp)
328{
329	struct led_trigger *trig;
330	int err;
331
332	trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
333
334	if (trig) {
335		trig->name = name;
336		err = led_trigger_register(trig);
337		if (err < 0) {
338			kfree(trig);
339			trig = NULL;
340			pr_warn("LED trigger %s failed to register (%d)\n",
341				name, err);
342		}
343	} else {
344		pr_warn("LED trigger %s failed to register (no memory)\n",
345			name);
346	}
347	*tp = trig;
348}
349EXPORT_SYMBOL_GPL(led_trigger_register_simple);
350
351void led_trigger_unregister_simple(struct led_trigger *trig)
352{
353	if (trig)
354		led_trigger_unregister(trig);
355	kfree(trig);
356}
357EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
358
359MODULE_AUTHOR("Richard Purdie");
360MODULE_LICENSE("GPL");
361MODULE_DESCRIPTION("LED Triggers Core");