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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 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");
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");