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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Class Core
4 *
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7 */
8
9#include <linux/ctype.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/timer.h>
21#include <uapi/linux/uleds.h>
22#include <linux/of.h>
23#include "leds.h"
24
25static DEFINE_MUTEX(leds_lookup_lock);
26static LIST_HEAD(leds_lookup_list);
27
28static struct workqueue_struct *leds_wq;
29
30static ssize_t brightness_show(struct device *dev,
31 struct device_attribute *attr, char *buf)
32{
33 struct led_classdev *led_cdev = dev_get_drvdata(dev);
34 unsigned int brightness;
35
36 mutex_lock(&led_cdev->led_access);
37 led_update_brightness(led_cdev);
38 brightness = led_cdev->brightness;
39 mutex_unlock(&led_cdev->led_access);
40
41 return sprintf(buf, "%u\n", brightness);
42}
43
44static ssize_t brightness_store(struct device *dev,
45 struct device_attribute *attr, const char *buf, size_t size)
46{
47 struct led_classdev *led_cdev = dev_get_drvdata(dev);
48 unsigned long state;
49 ssize_t ret;
50
51 mutex_lock(&led_cdev->led_access);
52
53 if (led_sysfs_is_disabled(led_cdev)) {
54 ret = -EBUSY;
55 goto unlock;
56 }
57
58 ret = kstrtoul(buf, 10, &state);
59 if (ret)
60 goto unlock;
61
62 if (state == LED_OFF)
63 led_trigger_remove(led_cdev);
64 led_set_brightness(led_cdev, state);
65
66 ret = size;
67unlock:
68 mutex_unlock(&led_cdev->led_access);
69 return ret;
70}
71static DEVICE_ATTR_RW(brightness);
72
73static ssize_t max_brightness_show(struct device *dev,
74 struct device_attribute *attr, char *buf)
75{
76 struct led_classdev *led_cdev = dev_get_drvdata(dev);
77 unsigned int max_brightness;
78
79 mutex_lock(&led_cdev->led_access);
80 max_brightness = led_cdev->max_brightness;
81 mutex_unlock(&led_cdev->led_access);
82
83 return sprintf(buf, "%u\n", max_brightness);
84}
85static DEVICE_ATTR_RO(max_brightness);
86
87#ifdef CONFIG_LEDS_TRIGGERS
88static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
89static struct bin_attribute *led_trigger_bin_attrs[] = {
90 &bin_attr_trigger,
91 NULL,
92};
93static const struct attribute_group led_trigger_group = {
94 .bin_attrs = led_trigger_bin_attrs,
95};
96#endif
97
98static struct attribute *led_class_attrs[] = {
99 &dev_attr_brightness.attr,
100 &dev_attr_max_brightness.attr,
101 NULL,
102};
103
104static const struct attribute_group led_group = {
105 .attrs = led_class_attrs,
106};
107
108static const struct attribute_group *led_groups[] = {
109 &led_group,
110#ifdef CONFIG_LEDS_TRIGGERS
111 &led_trigger_group,
112#endif
113 NULL,
114};
115
116#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
117static ssize_t brightness_hw_changed_show(struct device *dev,
118 struct device_attribute *attr, char *buf)
119{
120 struct led_classdev *led_cdev = dev_get_drvdata(dev);
121
122 if (led_cdev->brightness_hw_changed == -1)
123 return -ENODATA;
124
125 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
126}
127
128static DEVICE_ATTR_RO(brightness_hw_changed);
129
130static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
131{
132 struct device *dev = led_cdev->dev;
133 int ret;
134
135 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
136 if (ret) {
137 dev_err(dev, "Error creating brightness_hw_changed\n");
138 return ret;
139 }
140
141 led_cdev->brightness_hw_changed_kn =
142 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
143 if (!led_cdev->brightness_hw_changed_kn) {
144 dev_err(dev, "Error getting brightness_hw_changed kn\n");
145 device_remove_file(dev, &dev_attr_brightness_hw_changed);
146 return -ENXIO;
147 }
148
149 return 0;
150}
151
152static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
153{
154 sysfs_put(led_cdev->brightness_hw_changed_kn);
155 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
156}
157
158void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
159{
160 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
161 return;
162
163 led_cdev->brightness_hw_changed = brightness;
164 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
165}
166EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
167#else
168static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
169{
170 return 0;
171}
172static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
173{
174}
175#endif
176
177/**
178 * led_classdev_suspend - suspend an led_classdev.
179 * @led_cdev: the led_classdev to suspend.
180 */
181void led_classdev_suspend(struct led_classdev *led_cdev)
182{
183 led_cdev->flags |= LED_SUSPENDED;
184 led_set_brightness_nopm(led_cdev, 0);
185 flush_work(&led_cdev->set_brightness_work);
186}
187EXPORT_SYMBOL_GPL(led_classdev_suspend);
188
189/**
190 * led_classdev_resume - resume an led_classdev.
191 * @led_cdev: the led_classdev to resume.
192 */
193void led_classdev_resume(struct led_classdev *led_cdev)
194{
195 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
196
197 if (led_cdev->flash_resume)
198 led_cdev->flash_resume(led_cdev);
199
200 led_cdev->flags &= ~LED_SUSPENDED;
201}
202EXPORT_SYMBOL_GPL(led_classdev_resume);
203
204#ifdef CONFIG_PM_SLEEP
205static int led_suspend(struct device *dev)
206{
207 struct led_classdev *led_cdev = dev_get_drvdata(dev);
208
209 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
210 led_classdev_suspend(led_cdev);
211
212 return 0;
213}
214
215static int led_resume(struct device *dev)
216{
217 struct led_classdev *led_cdev = dev_get_drvdata(dev);
218
219 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
220 led_classdev_resume(led_cdev);
221
222 return 0;
223}
224#endif
225
226static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
227
228static struct led_classdev *led_module_get(struct device *led_dev)
229{
230 struct led_classdev *led_cdev;
231
232 if (!led_dev)
233 return ERR_PTR(-EPROBE_DEFER);
234
235 led_cdev = dev_get_drvdata(led_dev);
236
237 if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
238 put_device(led_cdev->dev);
239 return ERR_PTR(-ENODEV);
240 }
241
242 return led_cdev;
243}
244
245static const struct class leds_class = {
246 .name = "leds",
247 .dev_groups = led_groups,
248 .pm = &leds_class_dev_pm_ops,
249};
250
251/**
252 * of_led_get() - request a LED device via the LED framework
253 * @np: device node to get the LED device from
254 * @index: the index of the LED
255 *
256 * Returns the LED device parsed from the phandle specified in the "leds"
257 * property of a device tree node or a negative error-code on failure.
258 */
259struct led_classdev *of_led_get(struct device_node *np, int index)
260{
261 struct device *led_dev;
262 struct device_node *led_node;
263
264 led_node = of_parse_phandle(np, "leds", index);
265 if (!led_node)
266 return ERR_PTR(-ENOENT);
267
268 led_dev = class_find_device_by_of_node(&leds_class, led_node);
269 of_node_put(led_node);
270
271 return led_module_get(led_dev);
272}
273EXPORT_SYMBOL_GPL(of_led_get);
274
275/**
276 * led_put() - release a LED device
277 * @led_cdev: LED device
278 */
279void led_put(struct led_classdev *led_cdev)
280{
281 module_put(led_cdev->dev->parent->driver->owner);
282 put_device(led_cdev->dev);
283}
284EXPORT_SYMBOL_GPL(led_put);
285
286static void devm_led_release(struct device *dev, void *res)
287{
288 struct led_classdev **p = res;
289
290 led_put(*p);
291}
292
293static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
294{
295 struct led_classdev **dr;
296
297 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
298 if (!dr) {
299 led_put(led);
300 return ERR_PTR(-ENOMEM);
301 }
302
303 *dr = led;
304 devres_add(dev, dr);
305
306 return led;
307}
308
309/**
310 * devm_of_led_get - Resource-managed request of a LED device
311 * @dev: LED consumer
312 * @index: index of the LED to obtain in the consumer
313 *
314 * The device node of the device is parse to find the request LED device.
315 * The LED device returned from this function is automatically released
316 * on driver detach.
317 *
318 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
319 */
320struct led_classdev *__must_check devm_of_led_get(struct device *dev,
321 int index)
322{
323 struct led_classdev *led;
324
325 if (!dev)
326 return ERR_PTR(-EINVAL);
327
328 led = of_led_get(dev->of_node, index);
329 if (IS_ERR(led))
330 return led;
331
332 return __devm_led_get(dev, led);
333}
334EXPORT_SYMBOL_GPL(devm_of_led_get);
335
336/**
337 * led_get() - request a LED device via the LED framework
338 * @dev: device for which to get the LED device
339 * @con_id: name of the LED from the device's point of view
340 *
341 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
342 */
343struct led_classdev *led_get(struct device *dev, char *con_id)
344{
345 struct led_lookup_data *lookup;
346 const char *provider = NULL;
347 struct device *led_dev;
348
349 mutex_lock(&leds_lookup_lock);
350 list_for_each_entry(lookup, &leds_lookup_list, list) {
351 if (!strcmp(lookup->dev_id, dev_name(dev)) &&
352 !strcmp(lookup->con_id, con_id)) {
353 provider = kstrdup_const(lookup->provider, GFP_KERNEL);
354 break;
355 }
356 }
357 mutex_unlock(&leds_lookup_lock);
358
359 if (!provider)
360 return ERR_PTR(-ENOENT);
361
362 led_dev = class_find_device_by_name(&leds_class, provider);
363 kfree_const(provider);
364
365 return led_module_get(led_dev);
366}
367EXPORT_SYMBOL_GPL(led_get);
368
369/**
370 * devm_led_get() - request a LED device via the LED framework
371 * @dev: device for which to get the LED device
372 * @con_id: name of the LED from the device's point of view
373 *
374 * The LED device returned from this function is automatically released
375 * on driver detach.
376 *
377 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
378 */
379struct led_classdev *devm_led_get(struct device *dev, char *con_id)
380{
381 struct led_classdev *led;
382
383 led = led_get(dev, con_id);
384 if (IS_ERR(led))
385 return led;
386
387 return __devm_led_get(dev, led);
388}
389EXPORT_SYMBOL_GPL(devm_led_get);
390
391/**
392 * led_add_lookup() - Add a LED lookup table entry
393 * @led_lookup: the lookup table entry to add
394 *
395 * Add a LED lookup table entry. On systems without devicetree the lookup table
396 * is used by led_get() to find LEDs.
397 */
398void led_add_lookup(struct led_lookup_data *led_lookup)
399{
400 mutex_lock(&leds_lookup_lock);
401 list_add_tail(&led_lookup->list, &leds_lookup_list);
402 mutex_unlock(&leds_lookup_lock);
403}
404EXPORT_SYMBOL_GPL(led_add_lookup);
405
406/**
407 * led_remove_lookup() - Remove a LED lookup table entry
408 * @led_lookup: the lookup table entry to remove
409 */
410void led_remove_lookup(struct led_lookup_data *led_lookup)
411{
412 mutex_lock(&leds_lookup_lock);
413 list_del(&led_lookup->list);
414 mutex_unlock(&leds_lookup_lock);
415}
416EXPORT_SYMBOL_GPL(led_remove_lookup);
417
418/**
419 * devm_of_led_get_optional - Resource-managed request of an optional LED device
420 * @dev: LED consumer
421 * @index: index of the LED to obtain in the consumer
422 *
423 * The device node of the device is parsed to find the requested LED device.
424 * The LED device returned from this function is automatically released
425 * on driver detach.
426 *
427 * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
428 * led was not found.
429 */
430struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
431 int index)
432{
433 struct led_classdev *led;
434
435 led = devm_of_led_get(dev, index);
436 if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
437 return NULL;
438
439 return led;
440}
441EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
442
443static int led_classdev_next_name(const char *init_name, char *name,
444 size_t len)
445{
446 unsigned int i = 0;
447 int ret = 0;
448 struct device *dev;
449
450 strscpy(name, init_name, len);
451
452 while ((ret < len) &&
453 (dev = class_find_device_by_name(&leds_class, name))) {
454 put_device(dev);
455 ret = snprintf(name, len, "%s_%u", init_name, ++i);
456 }
457
458 if (ret >= len)
459 return -ENOMEM;
460
461 return i;
462}
463
464/**
465 * led_classdev_register_ext - register a new object of led_classdev class
466 * with init data.
467 *
468 * @parent: parent of LED device
469 * @led_cdev: the led_classdev structure for this device.
470 * @init_data: LED class device initialization data
471 */
472int led_classdev_register_ext(struct device *parent,
473 struct led_classdev *led_cdev,
474 struct led_init_data *init_data)
475{
476 char composed_name[LED_MAX_NAME_SIZE];
477 char final_name[LED_MAX_NAME_SIZE];
478 const char *proposed_name = composed_name;
479 int ret;
480
481 if (init_data) {
482 if (init_data->devname_mandatory && !init_data->devicename) {
483 dev_err(parent, "Mandatory device name is missing");
484 return -EINVAL;
485 }
486 ret = led_compose_name(parent, init_data, composed_name);
487 if (ret < 0)
488 return ret;
489
490 if (init_data->fwnode) {
491 fwnode_property_read_string(init_data->fwnode,
492 "linux,default-trigger",
493 &led_cdev->default_trigger);
494
495 if (fwnode_property_present(init_data->fwnode,
496 "retain-state-shutdown"))
497 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
498
499 fwnode_property_read_u32(init_data->fwnode,
500 "max-brightness",
501 &led_cdev->max_brightness);
502
503 if (fwnode_property_present(init_data->fwnode, "color"))
504 fwnode_property_read_u32(init_data->fwnode, "color",
505 &led_cdev->color);
506 }
507 } else {
508 proposed_name = led_cdev->name;
509 }
510
511 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
512 if (ret < 0)
513 return ret;
514 else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT)
515 return -EEXIST;
516 else if (ret)
517 dev_warn(parent, "Led %s renamed to %s due to name collision\n",
518 proposed_name, final_name);
519
520 if (led_cdev->color >= LED_COLOR_ID_MAX)
521 dev_warn(parent, "LED %s color identifier out of range\n", final_name);
522
523 mutex_init(&led_cdev->led_access);
524 mutex_lock(&led_cdev->led_access);
525 led_cdev->dev = device_create_with_groups(&leds_class, parent, 0,
526 led_cdev, led_cdev->groups, "%s", final_name);
527 if (IS_ERR(led_cdev->dev)) {
528 mutex_unlock(&led_cdev->led_access);
529 return PTR_ERR(led_cdev->dev);
530 }
531 if (init_data && init_data->fwnode)
532 device_set_node(led_cdev->dev, init_data->fwnode);
533
534 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
535 ret = led_add_brightness_hw_changed(led_cdev);
536 if (ret) {
537 device_unregister(led_cdev->dev);
538 led_cdev->dev = NULL;
539 mutex_unlock(&led_cdev->led_access);
540 return ret;
541 }
542 }
543
544 led_cdev->work_flags = 0;
545#ifdef CONFIG_LEDS_TRIGGERS
546 init_rwsem(&led_cdev->trigger_lock);
547#endif
548#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
549 led_cdev->brightness_hw_changed = -1;
550#endif
551 /* add to the list of leds */
552 down_write(&leds_list_lock);
553 list_add_tail(&led_cdev->node, &leds_list);
554 up_write(&leds_list_lock);
555
556 if (!led_cdev->max_brightness)
557 led_cdev->max_brightness = LED_FULL;
558
559 led_update_brightness(led_cdev);
560
561 led_cdev->wq = leds_wq;
562
563 led_init_core(led_cdev);
564
565#ifdef CONFIG_LEDS_TRIGGERS
566 led_trigger_set_default(led_cdev);
567#endif
568
569 mutex_unlock(&led_cdev->led_access);
570
571 dev_dbg(parent, "Registered led device: %s\n",
572 led_cdev->name);
573
574 return 0;
575}
576EXPORT_SYMBOL_GPL(led_classdev_register_ext);
577
578/**
579 * led_classdev_unregister - unregisters a object of led_properties class.
580 * @led_cdev: the led device to unregister
581 *
582 * Unregisters a previously registered via led_classdev_register object.
583 */
584void led_classdev_unregister(struct led_classdev *led_cdev)
585{
586 if (IS_ERR_OR_NULL(led_cdev->dev))
587 return;
588
589#ifdef CONFIG_LEDS_TRIGGERS
590 down_write(&led_cdev->trigger_lock);
591 if (led_cdev->trigger)
592 led_trigger_set(led_cdev, NULL);
593 up_write(&led_cdev->trigger_lock);
594#endif
595
596 led_cdev->flags |= LED_UNREGISTERING;
597
598 /* Stop blinking */
599 led_stop_software_blink(led_cdev);
600
601 if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
602 led_set_brightness(led_cdev, LED_OFF);
603
604 flush_work(&led_cdev->set_brightness_work);
605
606 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
607 led_remove_brightness_hw_changed(led_cdev);
608
609 device_unregister(led_cdev->dev);
610
611 down_write(&leds_list_lock);
612 list_del(&led_cdev->node);
613 up_write(&leds_list_lock);
614
615 mutex_destroy(&led_cdev->led_access);
616}
617EXPORT_SYMBOL_GPL(led_classdev_unregister);
618
619static void devm_led_classdev_release(struct device *dev, void *res)
620{
621 led_classdev_unregister(*(struct led_classdev **)res);
622}
623
624/**
625 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
626 *
627 * @parent: parent of LED device
628 * @led_cdev: the led_classdev structure for this device.
629 * @init_data: LED class device initialization data
630 */
631int devm_led_classdev_register_ext(struct device *parent,
632 struct led_classdev *led_cdev,
633 struct led_init_data *init_data)
634{
635 struct led_classdev **dr;
636 int rc;
637
638 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
639 if (!dr)
640 return -ENOMEM;
641
642 rc = led_classdev_register_ext(parent, led_cdev, init_data);
643 if (rc) {
644 devres_free(dr);
645 return rc;
646 }
647
648 *dr = led_cdev;
649 devres_add(parent, dr);
650
651 return 0;
652}
653EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
654
655static int devm_led_classdev_match(struct device *dev, void *res, void *data)
656{
657 struct led_classdev **p = res;
658
659 if (WARN_ON(!p || !*p))
660 return 0;
661
662 return *p == data;
663}
664
665/**
666 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
667 * @dev: The device to unregister.
668 * @led_cdev: the led_classdev structure for this device.
669 */
670void devm_led_classdev_unregister(struct device *dev,
671 struct led_classdev *led_cdev)
672{
673 WARN_ON(devres_release(dev,
674 devm_led_classdev_release,
675 devm_led_classdev_match, led_cdev));
676}
677EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
678
679static int __init leds_init(void)
680{
681 leds_wq = alloc_ordered_workqueue("leds", 0);
682 if (!leds_wq) {
683 pr_err("Failed to create LEDs ordered workqueue\n");
684 return -ENOMEM;
685 }
686
687 return class_register(&leds_class);
688}
689
690static void __exit leds_exit(void)
691{
692 class_unregister(&leds_class);
693 destroy_workqueue(leds_wq);
694}
695
696subsys_initcall(leds_init);
697module_exit(leds_exit);
698
699MODULE_AUTHOR("John Lenz, Richard Purdie");
700MODULE_LICENSE("GPL");
701MODULE_DESCRIPTION("LED Class Interface");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Class Core
4 *
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7 */
8
9#include <linux/ctype.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/timer.h>
21#include <uapi/linux/uleds.h>
22#include <linux/of.h>
23#include "leds.h"
24
25static DEFINE_MUTEX(leds_lookup_lock);
26static LIST_HEAD(leds_lookup_list);
27
28static ssize_t brightness_show(struct device *dev,
29 struct device_attribute *attr, char *buf)
30{
31 struct led_classdev *led_cdev = dev_get_drvdata(dev);
32
33 /* no lock needed for this */
34 led_update_brightness(led_cdev);
35
36 return sprintf(buf, "%u\n", led_cdev->brightness);
37}
38
39static ssize_t brightness_store(struct device *dev,
40 struct device_attribute *attr, const char *buf, size_t size)
41{
42 struct led_classdev *led_cdev = dev_get_drvdata(dev);
43 unsigned long state;
44 ssize_t ret;
45
46 mutex_lock(&led_cdev->led_access);
47
48 if (led_sysfs_is_disabled(led_cdev)) {
49 ret = -EBUSY;
50 goto unlock;
51 }
52
53 ret = kstrtoul(buf, 10, &state);
54 if (ret)
55 goto unlock;
56
57 if (state == LED_OFF)
58 led_trigger_remove(led_cdev);
59 led_set_brightness(led_cdev, state);
60 flush_work(&led_cdev->set_brightness_work);
61
62 ret = size;
63unlock:
64 mutex_unlock(&led_cdev->led_access);
65 return ret;
66}
67static DEVICE_ATTR_RW(brightness);
68
69static ssize_t max_brightness_show(struct device *dev,
70 struct device_attribute *attr, char *buf)
71{
72 struct led_classdev *led_cdev = dev_get_drvdata(dev);
73
74 return sprintf(buf, "%u\n", led_cdev->max_brightness);
75}
76static DEVICE_ATTR_RO(max_brightness);
77
78#ifdef CONFIG_LEDS_TRIGGERS
79static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
80static struct bin_attribute *led_trigger_bin_attrs[] = {
81 &bin_attr_trigger,
82 NULL,
83};
84static const struct attribute_group led_trigger_group = {
85 .bin_attrs = led_trigger_bin_attrs,
86};
87#endif
88
89static struct attribute *led_class_attrs[] = {
90 &dev_attr_brightness.attr,
91 &dev_attr_max_brightness.attr,
92 NULL,
93};
94
95static const struct attribute_group led_group = {
96 .attrs = led_class_attrs,
97};
98
99static const struct attribute_group *led_groups[] = {
100 &led_group,
101#ifdef CONFIG_LEDS_TRIGGERS
102 &led_trigger_group,
103#endif
104 NULL,
105};
106
107#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
108static ssize_t brightness_hw_changed_show(struct device *dev,
109 struct device_attribute *attr, char *buf)
110{
111 struct led_classdev *led_cdev = dev_get_drvdata(dev);
112
113 if (led_cdev->brightness_hw_changed == -1)
114 return -ENODATA;
115
116 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
117}
118
119static DEVICE_ATTR_RO(brightness_hw_changed);
120
121static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
122{
123 struct device *dev = led_cdev->dev;
124 int ret;
125
126 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
127 if (ret) {
128 dev_err(dev, "Error creating brightness_hw_changed\n");
129 return ret;
130 }
131
132 led_cdev->brightness_hw_changed_kn =
133 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
134 if (!led_cdev->brightness_hw_changed_kn) {
135 dev_err(dev, "Error getting brightness_hw_changed kn\n");
136 device_remove_file(dev, &dev_attr_brightness_hw_changed);
137 return -ENXIO;
138 }
139
140 return 0;
141}
142
143static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
144{
145 sysfs_put(led_cdev->brightness_hw_changed_kn);
146 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
147}
148
149void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
150{
151 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
152 return;
153
154 led_cdev->brightness_hw_changed = brightness;
155 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
156}
157EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
158#else
159static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
160{
161 return 0;
162}
163static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
164{
165}
166#endif
167
168/**
169 * led_classdev_suspend - suspend an led_classdev.
170 * @led_cdev: the led_classdev to suspend.
171 */
172void led_classdev_suspend(struct led_classdev *led_cdev)
173{
174 led_cdev->flags |= LED_SUSPENDED;
175 led_set_brightness_nopm(led_cdev, 0);
176 flush_work(&led_cdev->set_brightness_work);
177}
178EXPORT_SYMBOL_GPL(led_classdev_suspend);
179
180/**
181 * led_classdev_resume - resume an led_classdev.
182 * @led_cdev: the led_classdev to resume.
183 */
184void led_classdev_resume(struct led_classdev *led_cdev)
185{
186 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
187
188 if (led_cdev->flash_resume)
189 led_cdev->flash_resume(led_cdev);
190
191 led_cdev->flags &= ~LED_SUSPENDED;
192}
193EXPORT_SYMBOL_GPL(led_classdev_resume);
194
195#ifdef CONFIG_PM_SLEEP
196static int led_suspend(struct device *dev)
197{
198 struct led_classdev *led_cdev = dev_get_drvdata(dev);
199
200 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
201 led_classdev_suspend(led_cdev);
202
203 return 0;
204}
205
206static int led_resume(struct device *dev)
207{
208 struct led_classdev *led_cdev = dev_get_drvdata(dev);
209
210 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
211 led_classdev_resume(led_cdev);
212
213 return 0;
214}
215#endif
216
217static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
218
219static struct led_classdev *led_module_get(struct device *led_dev)
220{
221 struct led_classdev *led_cdev;
222
223 if (!led_dev)
224 return ERR_PTR(-EPROBE_DEFER);
225
226 led_cdev = dev_get_drvdata(led_dev);
227
228 if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
229 put_device(led_cdev->dev);
230 return ERR_PTR(-ENODEV);
231 }
232
233 return led_cdev;
234}
235
236static const struct class leds_class = {
237 .name = "leds",
238 .dev_groups = led_groups,
239 .pm = &leds_class_dev_pm_ops,
240};
241
242/**
243 * of_led_get() - request a LED device via the LED framework
244 * @np: device node to get the LED device from
245 * @index: the index of the LED
246 *
247 * Returns the LED device parsed from the phandle specified in the "leds"
248 * property of a device tree node or a negative error-code on failure.
249 */
250struct led_classdev *of_led_get(struct device_node *np, int index)
251{
252 struct device *led_dev;
253 struct device_node *led_node;
254
255 led_node = of_parse_phandle(np, "leds", index);
256 if (!led_node)
257 return ERR_PTR(-ENOENT);
258
259 led_dev = class_find_device_by_of_node(&leds_class, led_node);
260 of_node_put(led_node);
261 put_device(led_dev);
262
263 return led_module_get(led_dev);
264}
265EXPORT_SYMBOL_GPL(of_led_get);
266
267/**
268 * led_put() - release a LED device
269 * @led_cdev: LED device
270 */
271void led_put(struct led_classdev *led_cdev)
272{
273 module_put(led_cdev->dev->parent->driver->owner);
274 put_device(led_cdev->dev);
275}
276EXPORT_SYMBOL_GPL(led_put);
277
278static void devm_led_release(struct device *dev, void *res)
279{
280 struct led_classdev **p = res;
281
282 led_put(*p);
283}
284
285static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
286{
287 struct led_classdev **dr;
288
289 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
290 if (!dr) {
291 led_put(led);
292 return ERR_PTR(-ENOMEM);
293 }
294
295 *dr = led;
296 devres_add(dev, dr);
297
298 return led;
299}
300
301/**
302 * devm_of_led_get - Resource-managed request of a LED device
303 * @dev: LED consumer
304 * @index: index of the LED to obtain in the consumer
305 *
306 * The device node of the device is parse to find the request LED device.
307 * The LED device returned from this function is automatically released
308 * on driver detach.
309 *
310 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
311 */
312struct led_classdev *__must_check devm_of_led_get(struct device *dev,
313 int index)
314{
315 struct led_classdev *led;
316
317 if (!dev)
318 return ERR_PTR(-EINVAL);
319
320 led = of_led_get(dev->of_node, index);
321 if (IS_ERR(led))
322 return led;
323
324 return __devm_led_get(dev, led);
325}
326EXPORT_SYMBOL_GPL(devm_of_led_get);
327
328/**
329 * led_get() - request a LED device via the LED framework
330 * @dev: device for which to get the LED device
331 * @con_id: name of the LED from the device's point of view
332 *
333 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
334 */
335struct led_classdev *led_get(struct device *dev, char *con_id)
336{
337 struct led_lookup_data *lookup;
338 const char *provider = NULL;
339 struct device *led_dev;
340
341 mutex_lock(&leds_lookup_lock);
342 list_for_each_entry(lookup, &leds_lookup_list, list) {
343 if (!strcmp(lookup->dev_id, dev_name(dev)) &&
344 !strcmp(lookup->con_id, con_id)) {
345 provider = kstrdup_const(lookup->provider, GFP_KERNEL);
346 break;
347 }
348 }
349 mutex_unlock(&leds_lookup_lock);
350
351 if (!provider)
352 return ERR_PTR(-ENOENT);
353
354 led_dev = class_find_device_by_name(&leds_class, provider);
355 kfree_const(provider);
356
357 return led_module_get(led_dev);
358}
359EXPORT_SYMBOL_GPL(led_get);
360
361/**
362 * devm_led_get() - request a LED device via the LED framework
363 * @dev: device for which to get the LED device
364 * @con_id: name of the LED from the device's point of view
365 *
366 * The LED device returned from this function is automatically released
367 * on driver detach.
368 *
369 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
370 */
371struct led_classdev *devm_led_get(struct device *dev, char *con_id)
372{
373 struct led_classdev *led;
374
375 led = led_get(dev, con_id);
376 if (IS_ERR(led))
377 return led;
378
379 return __devm_led_get(dev, led);
380}
381EXPORT_SYMBOL_GPL(devm_led_get);
382
383/**
384 * led_add_lookup() - Add a LED lookup table entry
385 * @led_lookup: the lookup table entry to add
386 *
387 * Add a LED lookup table entry. On systems without devicetree the lookup table
388 * is used by led_get() to find LEDs.
389 */
390void led_add_lookup(struct led_lookup_data *led_lookup)
391{
392 mutex_lock(&leds_lookup_lock);
393 list_add_tail(&led_lookup->list, &leds_lookup_list);
394 mutex_unlock(&leds_lookup_lock);
395}
396EXPORT_SYMBOL_GPL(led_add_lookup);
397
398/**
399 * led_remove_lookup() - Remove a LED lookup table entry
400 * @led_lookup: the lookup table entry to remove
401 */
402void led_remove_lookup(struct led_lookup_data *led_lookup)
403{
404 mutex_lock(&leds_lookup_lock);
405 list_del(&led_lookup->list);
406 mutex_unlock(&leds_lookup_lock);
407}
408EXPORT_SYMBOL_GPL(led_remove_lookup);
409
410/**
411 * devm_of_led_get_optional - Resource-managed request of an optional LED device
412 * @dev: LED consumer
413 * @index: index of the LED to obtain in the consumer
414 *
415 * The device node of the device is parsed to find the requested LED device.
416 * The LED device returned from this function is automatically released
417 * on driver detach.
418 *
419 * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
420 * led was not found.
421 */
422struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
423 int index)
424{
425 struct led_classdev *led;
426
427 led = devm_of_led_get(dev, index);
428 if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
429 return NULL;
430
431 return led;
432}
433EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
434
435static int led_classdev_next_name(const char *init_name, char *name,
436 size_t len)
437{
438 unsigned int i = 0;
439 int ret = 0;
440 struct device *dev;
441
442 strscpy(name, init_name, len);
443
444 while ((ret < len) &&
445 (dev = class_find_device_by_name(&leds_class, name))) {
446 put_device(dev);
447 ret = snprintf(name, len, "%s_%u", init_name, ++i);
448 }
449
450 if (ret >= len)
451 return -ENOMEM;
452
453 return i;
454}
455
456/**
457 * led_classdev_register_ext - register a new object of led_classdev class
458 * with init data.
459 *
460 * @parent: parent of LED device
461 * @led_cdev: the led_classdev structure for this device.
462 * @init_data: LED class device initialization data
463 */
464int led_classdev_register_ext(struct device *parent,
465 struct led_classdev *led_cdev,
466 struct led_init_data *init_data)
467{
468 char composed_name[LED_MAX_NAME_SIZE];
469 char final_name[LED_MAX_NAME_SIZE];
470 const char *proposed_name = composed_name;
471 int ret;
472
473 if (init_data) {
474 if (init_data->devname_mandatory && !init_data->devicename) {
475 dev_err(parent, "Mandatory device name is missing");
476 return -EINVAL;
477 }
478 ret = led_compose_name(parent, init_data, composed_name);
479 if (ret < 0)
480 return ret;
481
482 if (init_data->fwnode) {
483 fwnode_property_read_string(init_data->fwnode,
484 "linux,default-trigger",
485 &led_cdev->default_trigger);
486
487 if (fwnode_property_present(init_data->fwnode,
488 "retain-state-shutdown"))
489 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
490
491 fwnode_property_read_u32(init_data->fwnode,
492 "max-brightness",
493 &led_cdev->max_brightness);
494
495 if (fwnode_property_present(init_data->fwnode, "color"))
496 fwnode_property_read_u32(init_data->fwnode, "color",
497 &led_cdev->color);
498 }
499 } else {
500 proposed_name = led_cdev->name;
501 }
502
503 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
504 if (ret < 0)
505 return ret;
506
507 if (led_cdev->color >= LED_COLOR_ID_MAX)
508 dev_warn(parent, "LED %s color identifier out of range\n", final_name);
509
510 mutex_init(&led_cdev->led_access);
511 mutex_lock(&led_cdev->led_access);
512 led_cdev->dev = device_create_with_groups(&leds_class, parent, 0,
513 led_cdev, led_cdev->groups, "%s", final_name);
514 if (IS_ERR(led_cdev->dev)) {
515 mutex_unlock(&led_cdev->led_access);
516 return PTR_ERR(led_cdev->dev);
517 }
518 if (init_data && init_data->fwnode)
519 device_set_node(led_cdev->dev, init_data->fwnode);
520
521 if (ret)
522 dev_warn(parent, "Led %s renamed to %s due to name collision",
523 proposed_name, dev_name(led_cdev->dev));
524
525 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
526 ret = led_add_brightness_hw_changed(led_cdev);
527 if (ret) {
528 device_unregister(led_cdev->dev);
529 led_cdev->dev = NULL;
530 mutex_unlock(&led_cdev->led_access);
531 return ret;
532 }
533 }
534
535 led_cdev->work_flags = 0;
536#ifdef CONFIG_LEDS_TRIGGERS
537 init_rwsem(&led_cdev->trigger_lock);
538#endif
539#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
540 led_cdev->brightness_hw_changed = -1;
541#endif
542 /* add to the list of leds */
543 down_write(&leds_list_lock);
544 list_add_tail(&led_cdev->node, &leds_list);
545 up_write(&leds_list_lock);
546
547 if (!led_cdev->max_brightness)
548 led_cdev->max_brightness = LED_FULL;
549
550 led_update_brightness(led_cdev);
551
552 led_init_core(led_cdev);
553
554#ifdef CONFIG_LEDS_TRIGGERS
555 led_trigger_set_default(led_cdev);
556#endif
557
558 mutex_unlock(&led_cdev->led_access);
559
560 dev_dbg(parent, "Registered led device: %s\n",
561 led_cdev->name);
562
563 return 0;
564}
565EXPORT_SYMBOL_GPL(led_classdev_register_ext);
566
567/**
568 * led_classdev_unregister - unregisters a object of led_properties class.
569 * @led_cdev: the led device to unregister
570 *
571 * Unregisters a previously registered via led_classdev_register object.
572 */
573void led_classdev_unregister(struct led_classdev *led_cdev)
574{
575 if (IS_ERR_OR_NULL(led_cdev->dev))
576 return;
577
578#ifdef CONFIG_LEDS_TRIGGERS
579 down_write(&led_cdev->trigger_lock);
580 if (led_cdev->trigger)
581 led_trigger_set(led_cdev, NULL);
582 up_write(&led_cdev->trigger_lock);
583#endif
584
585 led_cdev->flags |= LED_UNREGISTERING;
586
587 /* Stop blinking */
588 led_stop_software_blink(led_cdev);
589
590 if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
591 led_set_brightness(led_cdev, LED_OFF);
592
593 flush_work(&led_cdev->set_brightness_work);
594
595 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
596 led_remove_brightness_hw_changed(led_cdev);
597
598 device_unregister(led_cdev->dev);
599
600 down_write(&leds_list_lock);
601 list_del(&led_cdev->node);
602 up_write(&leds_list_lock);
603
604 mutex_destroy(&led_cdev->led_access);
605}
606EXPORT_SYMBOL_GPL(led_classdev_unregister);
607
608static void devm_led_classdev_release(struct device *dev, void *res)
609{
610 led_classdev_unregister(*(struct led_classdev **)res);
611}
612
613/**
614 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
615 *
616 * @parent: parent of LED device
617 * @led_cdev: the led_classdev structure for this device.
618 * @init_data: LED class device initialization data
619 */
620int devm_led_classdev_register_ext(struct device *parent,
621 struct led_classdev *led_cdev,
622 struct led_init_data *init_data)
623{
624 struct led_classdev **dr;
625 int rc;
626
627 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
628 if (!dr)
629 return -ENOMEM;
630
631 rc = led_classdev_register_ext(parent, led_cdev, init_data);
632 if (rc) {
633 devres_free(dr);
634 return rc;
635 }
636
637 *dr = led_cdev;
638 devres_add(parent, dr);
639
640 return 0;
641}
642EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
643
644static int devm_led_classdev_match(struct device *dev, void *res, void *data)
645{
646 struct led_classdev **p = res;
647
648 if (WARN_ON(!p || !*p))
649 return 0;
650
651 return *p == data;
652}
653
654/**
655 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
656 * @dev: The device to unregister.
657 * @led_cdev: the led_classdev structure for this device.
658 */
659void devm_led_classdev_unregister(struct device *dev,
660 struct led_classdev *led_cdev)
661{
662 WARN_ON(devres_release(dev,
663 devm_led_classdev_release,
664 devm_led_classdev_match, led_cdev));
665}
666EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
667
668static int __init leds_init(void)
669{
670 return class_register(&leds_class);
671}
672
673static void __exit leds_exit(void)
674{
675 class_unregister(&leds_class);
676}
677
678subsys_initcall(leds_init);
679module_exit(leds_exit);
680
681MODULE_AUTHOR("John Lenz, Richard Purdie");
682MODULE_LICENSE("GPL");
683MODULE_DESCRIPTION("LED Class Interface");