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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 struct class *leds_class;
26
27static ssize_t brightness_show(struct device *dev,
28 struct device_attribute *attr, char *buf)
29{
30 struct led_classdev *led_cdev = dev_get_drvdata(dev);
31
32 /* no lock needed for this */
33 led_update_brightness(led_cdev);
34
35 return sprintf(buf, "%u\n", led_cdev->brightness);
36}
37
38static ssize_t brightness_store(struct device *dev,
39 struct device_attribute *attr, const char *buf, size_t size)
40{
41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
42 unsigned long state;
43 ssize_t ret;
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 ret = kstrtoul(buf, 10, &state);
53 if (ret)
54 goto unlock;
55
56 if (state == LED_OFF)
57 led_trigger_remove(led_cdev);
58 led_set_brightness(led_cdev, state);
59 flush_work(&led_cdev->set_brightness_work);
60
61 ret = size;
62unlock:
63 mutex_unlock(&led_cdev->led_access);
64 return ret;
65}
66static DEVICE_ATTR_RW(brightness);
67
68static ssize_t max_brightness_show(struct device *dev,
69 struct device_attribute *attr, char *buf)
70{
71 struct led_classdev *led_cdev = dev_get_drvdata(dev);
72
73 return sprintf(buf, "%u\n", led_cdev->max_brightness);
74}
75static DEVICE_ATTR_RO(max_brightness);
76
77#ifdef CONFIG_LEDS_TRIGGERS
78static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
79static struct bin_attribute *led_trigger_bin_attrs[] = {
80 &bin_attr_trigger,
81 NULL,
82};
83static const struct attribute_group led_trigger_group = {
84 .bin_attrs = led_trigger_bin_attrs,
85};
86#endif
87
88static struct attribute *led_class_attrs[] = {
89 &dev_attr_brightness.attr,
90 &dev_attr_max_brightness.attr,
91 NULL,
92};
93
94static const struct attribute_group led_group = {
95 .attrs = led_class_attrs,
96};
97
98static const struct attribute_group *led_groups[] = {
99 &led_group,
100#ifdef CONFIG_LEDS_TRIGGERS
101 &led_trigger_group,
102#endif
103 NULL,
104};
105
106#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
107static ssize_t brightness_hw_changed_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
109{
110 struct led_classdev *led_cdev = dev_get_drvdata(dev);
111
112 if (led_cdev->brightness_hw_changed == -1)
113 return -ENODATA;
114
115 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
116}
117
118static DEVICE_ATTR_RO(brightness_hw_changed);
119
120static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
121{
122 struct device *dev = led_cdev->dev;
123 int ret;
124
125 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
126 if (ret) {
127 dev_err(dev, "Error creating brightness_hw_changed\n");
128 return ret;
129 }
130
131 led_cdev->brightness_hw_changed_kn =
132 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
133 if (!led_cdev->brightness_hw_changed_kn) {
134 dev_err(dev, "Error getting brightness_hw_changed kn\n");
135 device_remove_file(dev, &dev_attr_brightness_hw_changed);
136 return -ENXIO;
137 }
138
139 return 0;
140}
141
142static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
143{
144 sysfs_put(led_cdev->brightness_hw_changed_kn);
145 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
146}
147
148void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
149{
150 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
151 return;
152
153 led_cdev->brightness_hw_changed = brightness;
154 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
155}
156EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
157#else
158static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
159{
160 return 0;
161}
162static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
163{
164}
165#endif
166
167/**
168 * led_classdev_suspend - suspend an led_classdev.
169 * @led_cdev: the led_classdev to suspend.
170 */
171void led_classdev_suspend(struct led_classdev *led_cdev)
172{
173 led_cdev->flags |= LED_SUSPENDED;
174 led_set_brightness_nopm(led_cdev, 0);
175 flush_work(&led_cdev->set_brightness_work);
176}
177EXPORT_SYMBOL_GPL(led_classdev_suspend);
178
179/**
180 * led_classdev_resume - resume an led_classdev.
181 * @led_cdev: the led_classdev to resume.
182 */
183void led_classdev_resume(struct led_classdev *led_cdev)
184{
185 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
186
187 if (led_cdev->flash_resume)
188 led_cdev->flash_resume(led_cdev);
189
190 led_cdev->flags &= ~LED_SUSPENDED;
191}
192EXPORT_SYMBOL_GPL(led_classdev_resume);
193
194#ifdef CONFIG_PM_SLEEP
195static int led_suspend(struct device *dev)
196{
197 struct led_classdev *led_cdev = dev_get_drvdata(dev);
198
199 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
200 led_classdev_suspend(led_cdev);
201
202 return 0;
203}
204
205static int led_resume(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_resume(led_cdev);
211
212 return 0;
213}
214#endif
215
216static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
217
218/**
219 * of_led_get() - request a LED device via the LED framework
220 * @np: device node to get the LED device from
221 * @index: the index of the LED
222 *
223 * Returns the LED device parsed from the phandle specified in the "leds"
224 * property of a device tree node or a negative error-code on failure.
225 */
226struct led_classdev *of_led_get(struct device_node *np, int index)
227{
228 struct device *led_dev;
229 struct led_classdev *led_cdev;
230 struct device_node *led_node;
231
232 led_node = of_parse_phandle(np, "leds", index);
233 if (!led_node)
234 return ERR_PTR(-ENOENT);
235
236 led_dev = class_find_device_by_of_node(leds_class, led_node);
237 of_node_put(led_node);
238
239 if (!led_dev)
240 return ERR_PTR(-EPROBE_DEFER);
241
242 led_cdev = dev_get_drvdata(led_dev);
243
244 if (!try_module_get(led_cdev->dev->parent->driver->owner))
245 return ERR_PTR(-ENODEV);
246
247 return led_cdev;
248}
249EXPORT_SYMBOL_GPL(of_led_get);
250
251/**
252 * led_put() - release a LED device
253 * @led_cdev: LED device
254 */
255void led_put(struct led_classdev *led_cdev)
256{
257 module_put(led_cdev->dev->parent->driver->owner);
258}
259EXPORT_SYMBOL_GPL(led_put);
260
261static void devm_led_release(struct device *dev, void *res)
262{
263 struct led_classdev **p = res;
264
265 led_put(*p);
266}
267
268/**
269 * devm_of_led_get - Resource-managed request of a LED device
270 * @dev: LED consumer
271 * @index: index of the LED to obtain in the consumer
272 *
273 * The device node of the device is parse to find the request LED device.
274 * The LED device returned from this function is automatically released
275 * on driver detach.
276 *
277 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
278 */
279struct led_classdev *__must_check devm_of_led_get(struct device *dev,
280 int index)
281{
282 struct led_classdev *led;
283 struct led_classdev **dr;
284
285 if (!dev)
286 return ERR_PTR(-EINVAL);
287
288 led = of_led_get(dev->of_node, index);
289 if (IS_ERR(led))
290 return led;
291
292 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
293 GFP_KERNEL);
294 if (!dr) {
295 led_put(led);
296 return ERR_PTR(-ENOMEM);
297 }
298
299 *dr = led;
300 devres_add(dev, dr);
301
302 return led;
303}
304EXPORT_SYMBOL_GPL(devm_of_led_get);
305
306static int led_classdev_next_name(const char *init_name, char *name,
307 size_t len)
308{
309 unsigned int i = 0;
310 int ret = 0;
311 struct device *dev;
312
313 strlcpy(name, init_name, len);
314
315 while ((ret < len) &&
316 (dev = class_find_device_by_name(leds_class, name))) {
317 put_device(dev);
318 ret = snprintf(name, len, "%s_%u", init_name, ++i);
319 }
320
321 if (ret >= len)
322 return -ENOMEM;
323
324 return i;
325}
326
327/**
328 * led_classdev_register_ext - register a new object of led_classdev class
329 * with init data.
330 *
331 * @parent: parent of LED device
332 * @led_cdev: the led_classdev structure for this device.
333 * @init_data: LED class device initialization data
334 */
335int led_classdev_register_ext(struct device *parent,
336 struct led_classdev *led_cdev,
337 struct led_init_data *init_data)
338{
339 char composed_name[LED_MAX_NAME_SIZE];
340 char final_name[LED_MAX_NAME_SIZE];
341 const char *proposed_name = composed_name;
342 int ret;
343
344 if (init_data) {
345 if (init_data->devname_mandatory && !init_data->devicename) {
346 dev_err(parent, "Mandatory device name is missing");
347 return -EINVAL;
348 }
349 ret = led_compose_name(parent, init_data, composed_name);
350 if (ret < 0)
351 return ret;
352
353 if (init_data->fwnode) {
354 fwnode_property_read_string(init_data->fwnode,
355 "linux,default-trigger",
356 &led_cdev->default_trigger);
357
358 if (fwnode_property_present(init_data->fwnode,
359 "retain-state-shutdown"))
360 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
361 }
362 } else {
363 proposed_name = led_cdev->name;
364 }
365
366 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
367 if (ret < 0)
368 return ret;
369
370 mutex_init(&led_cdev->led_access);
371 mutex_lock(&led_cdev->led_access);
372 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
373 led_cdev, led_cdev->groups, "%s", final_name);
374 if (IS_ERR(led_cdev->dev)) {
375 mutex_unlock(&led_cdev->led_access);
376 return PTR_ERR(led_cdev->dev);
377 }
378 if (init_data && init_data->fwnode)
379 device_set_node(led_cdev->dev, init_data->fwnode);
380
381 if (ret)
382 dev_warn(parent, "Led %s renamed to %s due to name collision",
383 proposed_name, dev_name(led_cdev->dev));
384
385 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
386 ret = led_add_brightness_hw_changed(led_cdev);
387 if (ret) {
388 device_unregister(led_cdev->dev);
389 led_cdev->dev = NULL;
390 mutex_unlock(&led_cdev->led_access);
391 return ret;
392 }
393 }
394
395 led_cdev->work_flags = 0;
396#ifdef CONFIG_LEDS_TRIGGERS
397 init_rwsem(&led_cdev->trigger_lock);
398#endif
399#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
400 led_cdev->brightness_hw_changed = -1;
401#endif
402 /* add to the list of leds */
403 down_write(&leds_list_lock);
404 list_add_tail(&led_cdev->node, &leds_list);
405 up_write(&leds_list_lock);
406
407 if (!led_cdev->max_brightness)
408 led_cdev->max_brightness = LED_FULL;
409
410 led_update_brightness(led_cdev);
411
412 led_init_core(led_cdev);
413
414#ifdef CONFIG_LEDS_TRIGGERS
415 led_trigger_set_default(led_cdev);
416#endif
417
418 mutex_unlock(&led_cdev->led_access);
419
420 dev_dbg(parent, "Registered led device: %s\n",
421 led_cdev->name);
422
423 return 0;
424}
425EXPORT_SYMBOL_GPL(led_classdev_register_ext);
426
427/**
428 * led_classdev_unregister - unregisters a object of led_properties class.
429 * @led_cdev: the led device to unregister
430 *
431 * Unregisters a previously registered via led_classdev_register object.
432 */
433void led_classdev_unregister(struct led_classdev *led_cdev)
434{
435 if (IS_ERR_OR_NULL(led_cdev->dev))
436 return;
437
438#ifdef CONFIG_LEDS_TRIGGERS
439 down_write(&led_cdev->trigger_lock);
440 if (led_cdev->trigger)
441 led_trigger_set(led_cdev, NULL);
442 up_write(&led_cdev->trigger_lock);
443#endif
444
445 led_cdev->flags |= LED_UNREGISTERING;
446
447 /* Stop blinking */
448 led_stop_software_blink(led_cdev);
449
450 if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
451 led_set_brightness(led_cdev, LED_OFF);
452
453 flush_work(&led_cdev->set_brightness_work);
454
455 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
456 led_remove_brightness_hw_changed(led_cdev);
457
458 device_unregister(led_cdev->dev);
459
460 down_write(&leds_list_lock);
461 list_del(&led_cdev->node);
462 up_write(&leds_list_lock);
463
464 mutex_destroy(&led_cdev->led_access);
465}
466EXPORT_SYMBOL_GPL(led_classdev_unregister);
467
468static void devm_led_classdev_release(struct device *dev, void *res)
469{
470 led_classdev_unregister(*(struct led_classdev **)res);
471}
472
473/**
474 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
475 *
476 * @parent: parent of LED device
477 * @led_cdev: the led_classdev structure for this device.
478 * @init_data: LED class device initialization data
479 */
480int devm_led_classdev_register_ext(struct device *parent,
481 struct led_classdev *led_cdev,
482 struct led_init_data *init_data)
483{
484 struct led_classdev **dr;
485 int rc;
486
487 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
488 if (!dr)
489 return -ENOMEM;
490
491 rc = led_classdev_register_ext(parent, led_cdev, init_data);
492 if (rc) {
493 devres_free(dr);
494 return rc;
495 }
496
497 *dr = led_cdev;
498 devres_add(parent, dr);
499
500 return 0;
501}
502EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
503
504static int devm_led_classdev_match(struct device *dev, void *res, void *data)
505{
506 struct led_classdev **p = res;
507
508 if (WARN_ON(!p || !*p))
509 return 0;
510
511 return *p == data;
512}
513
514/**
515 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
516 * @dev: The device to unregister.
517 * @led_cdev: the led_classdev structure for this device.
518 */
519void devm_led_classdev_unregister(struct device *dev,
520 struct led_classdev *led_cdev)
521{
522 WARN_ON(devres_release(dev,
523 devm_led_classdev_release,
524 devm_led_classdev_match, led_cdev));
525}
526EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
527
528static int __init leds_init(void)
529{
530 leds_class = class_create(THIS_MODULE, "leds");
531 if (IS_ERR(leds_class))
532 return PTR_ERR(leds_class);
533 leds_class->pm = &leds_class_dev_pm_ops;
534 leds_class->dev_groups = led_groups;
535 return 0;
536}
537
538static void __exit leds_exit(void)
539{
540 class_destroy(leds_class);
541}
542
543subsys_initcall(leds_init);
544module_exit(leds_exit);
545
546MODULE_AUTHOR("John Lenz, Richard Purdie");
547MODULE_LICENSE("GPL");
548MODULE_DESCRIPTION("LED Class Interface");