1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
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>
25 static DEFINE_MUTEX(leds_lookup_lock);
26 static LIST_HEAD(leds_lookup_list);
28 static ssize_t brightness_show(struct device *dev,
29 struct device_attribute *attr, char *buf)
31 struct led_classdev *led_cdev = dev_get_drvdata(dev);
33 /* no lock needed for this */
34 led_update_brightness(led_cdev);
36 return sprintf(buf, "%u\n", led_cdev->brightness);
39 static ssize_t brightness_store(struct device *dev,
40 struct device_attribute *attr, const char *buf, size_t size)
42 struct led_classdev *led_cdev = dev_get_drvdata(dev);
46 mutex_lock(&led_cdev->led_access);
48 if (led_sysfs_is_disabled(led_cdev)) {
53 ret = kstrtoul(buf, 10, &state);
58 led_trigger_remove(led_cdev);
59 led_set_brightness(led_cdev, state);
60 flush_work(&led_cdev->set_brightness_work);
64 mutex_unlock(&led_cdev->led_access);
67 static DEVICE_ATTR_RW(brightness);
69 static ssize_t max_brightness_show(struct device *dev,
70 struct device_attribute *attr, char *buf)
72 struct led_classdev *led_cdev = dev_get_drvdata(dev);
74 return sprintf(buf, "%u\n", led_cdev->max_brightness);
76 static DEVICE_ATTR_RO(max_brightness);
78 #ifdef CONFIG_LEDS_TRIGGERS
79 static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
80 static struct bin_attribute *led_trigger_bin_attrs[] = {
84 static const struct attribute_group led_trigger_group = {
85 .bin_attrs = led_trigger_bin_attrs,
89 static struct attribute *led_class_attrs[] = {
90 &dev_attr_brightness.attr,
91 &dev_attr_max_brightness.attr,
95 static const struct attribute_group led_group = {
96 .attrs = led_class_attrs,
99 static const struct attribute_group *led_groups[] = {
101 #ifdef CONFIG_LEDS_TRIGGERS
107 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
108 static ssize_t brightness_hw_changed_show(struct device *dev,
109 struct device_attribute *attr, char *buf)
111 struct led_classdev *led_cdev = dev_get_drvdata(dev);
113 if (led_cdev->brightness_hw_changed == -1)
116 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
119 static DEVICE_ATTR_RO(brightness_hw_changed);
121 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
123 struct device *dev = led_cdev->dev;
126 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
128 dev_err(dev, "Error creating brightness_hw_changed\n");
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);
143 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
145 sysfs_put(led_cdev->brightness_hw_changed_kn);
146 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
149 void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
151 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
154 led_cdev->brightness_hw_changed = brightness;
155 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
157 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
159 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
163 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
169 * led_classdev_suspend - suspend an led_classdev.
170 * @led_cdev: the led_classdev to suspend.
172 void led_classdev_suspend(struct led_classdev *led_cdev)
174 led_cdev->flags |= LED_SUSPENDED;
175 led_set_brightness_nopm(led_cdev, 0);
176 flush_work(&led_cdev->set_brightness_work);
178 EXPORT_SYMBOL_GPL(led_classdev_suspend);
181 * led_classdev_resume - resume an led_classdev.
182 * @led_cdev: the led_classdev to resume.
184 void led_classdev_resume(struct led_classdev *led_cdev)
186 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
188 if (led_cdev->flash_resume)
189 led_cdev->flash_resume(led_cdev);
191 led_cdev->flags &= ~LED_SUSPENDED;
193 EXPORT_SYMBOL_GPL(led_classdev_resume);
195 #ifdef CONFIG_PM_SLEEP
196 static int led_suspend(struct device *dev)
198 struct led_classdev *led_cdev = dev_get_drvdata(dev);
200 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
201 led_classdev_suspend(led_cdev);
206 static int led_resume(struct device *dev)
208 struct led_classdev *led_cdev = dev_get_drvdata(dev);
210 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
211 led_classdev_resume(led_cdev);
217 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
219 static struct led_classdev *led_module_get(struct device *led_dev)
221 struct led_classdev *led_cdev;
224 return ERR_PTR(-EPROBE_DEFER);
226 led_cdev = dev_get_drvdata(led_dev);
228 if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
229 put_device(led_cdev->dev);
230 return ERR_PTR(-ENODEV);
236 static const struct class leds_class = {
238 .dev_groups = led_groups,
239 .pm = &leds_class_dev_pm_ops,
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
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.
250 struct led_classdev *of_led_get(struct device_node *np, int index)
252 struct device *led_dev;
253 struct device_node *led_node;
255 led_node = of_parse_phandle(np, "leds", index);
257 return ERR_PTR(-ENOENT);
259 led_dev = class_find_device_by_of_node(&leds_class, led_node);
260 of_node_put(led_node);
263 return led_module_get(led_dev);
265 EXPORT_SYMBOL_GPL(of_led_get);
268 * led_put() - release a LED device
269 * @led_cdev: LED device
271 void led_put(struct led_classdev *led_cdev)
273 module_put(led_cdev->dev->parent->driver->owner);
274 put_device(led_cdev->dev);
276 EXPORT_SYMBOL_GPL(led_put);
278 static void devm_led_release(struct device *dev, void *res)
280 struct led_classdev **p = res;
285 static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
287 struct led_classdev **dr;
289 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
292 return ERR_PTR(-ENOMEM);
302 * devm_of_led_get - Resource-managed request of a LED device
304 * @index: index of the LED to obtain in the consumer
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
310 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
312 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
315 struct led_classdev *led;
318 return ERR_PTR(-EINVAL);
320 led = of_led_get(dev->of_node, index);
324 return __devm_led_get(dev, led);
326 EXPORT_SYMBOL_GPL(devm_of_led_get);
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
333 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
335 struct led_classdev *led_get(struct device *dev, char *con_id)
337 struct led_lookup_data *lookup;
338 const char *provider = NULL;
339 struct device *led_dev;
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);
349 mutex_unlock(&leds_lookup_lock);
352 return ERR_PTR(-ENOENT);
354 led_dev = class_find_device_by_name(&leds_class, provider);
355 kfree_const(provider);
357 return led_module_get(led_dev);
359 EXPORT_SYMBOL_GPL(led_get);
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
366 * The LED device returned from this function is automatically released
369 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
371 struct led_classdev *devm_led_get(struct device *dev, char *con_id)
373 struct led_classdev *led;
375 led = led_get(dev, con_id);
379 return __devm_led_get(dev, led);
381 EXPORT_SYMBOL_GPL(devm_led_get);
384 * led_add_lookup() - Add a LED lookup table entry
385 * @led_lookup: the lookup table entry to add
387 * Add a LED lookup table entry. On systems without devicetree the lookup table
388 * is used by led_get() to find LEDs.
390 void led_add_lookup(struct led_lookup_data *led_lookup)
392 mutex_lock(&leds_lookup_lock);
393 list_add_tail(&led_lookup->list, &leds_lookup_list);
394 mutex_unlock(&leds_lookup_lock);
396 EXPORT_SYMBOL_GPL(led_add_lookup);
399 * led_remove_lookup() - Remove a LED lookup table entry
400 * @led_lookup: the lookup table entry to remove
402 void led_remove_lookup(struct led_lookup_data *led_lookup)
404 mutex_lock(&leds_lookup_lock);
405 list_del(&led_lookup->list);
406 mutex_unlock(&leds_lookup_lock);
408 EXPORT_SYMBOL_GPL(led_remove_lookup);
411 * devm_of_led_get_optional - Resource-managed request of an optional LED device
413 * @index: index of the LED to obtain in the consumer
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
419 * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
422 struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
425 struct led_classdev *led;
427 led = devm_of_led_get(dev, index);
428 if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
433 EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
435 static int led_classdev_next_name(const char *init_name, char *name,
442 strscpy(name, init_name, len);
444 while ((ret < len) &&
445 (dev = class_find_device_by_name(&leds_class, name))) {
447 ret = snprintf(name, len, "%s_%u", init_name, ++i);
457 * led_classdev_register_ext - register a new object of led_classdev class
460 * @parent: parent of LED device
461 * @led_cdev: the led_classdev structure for this device.
462 * @init_data: LED class device initialization data
464 int led_classdev_register_ext(struct device *parent,
465 struct led_classdev *led_cdev,
466 struct led_init_data *init_data)
468 char composed_name[LED_MAX_NAME_SIZE];
469 char final_name[LED_MAX_NAME_SIZE];
470 const char *proposed_name = composed_name;
474 if (init_data->devname_mandatory && !init_data->devicename) {
475 dev_err(parent, "Mandatory device name is missing");
478 ret = led_compose_name(parent, init_data, composed_name);
482 if (init_data->fwnode) {
483 fwnode_property_read_string(init_data->fwnode,
484 "linux,default-trigger",
485 &led_cdev->default_trigger);
487 if (fwnode_property_present(init_data->fwnode,
488 "retain-state-shutdown"))
489 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
491 fwnode_property_read_u32(init_data->fwnode,
493 &led_cdev->max_brightness);
495 if (fwnode_property_present(init_data->fwnode, "color"))
496 fwnode_property_read_u32(init_data->fwnode, "color",
500 proposed_name = led_cdev->name;
503 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
507 if (led_cdev->color >= LED_COLOR_ID_MAX)
508 dev_warn(parent, "LED %s color identifier out of range\n", final_name);
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);
518 if (init_data && init_data->fwnode)
519 device_set_node(led_cdev->dev, init_data->fwnode);
522 dev_warn(parent, "Led %s renamed to %s due to name collision",
523 proposed_name, dev_name(led_cdev->dev));
525 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
526 ret = led_add_brightness_hw_changed(led_cdev);
528 device_unregister(led_cdev->dev);
529 led_cdev->dev = NULL;
530 mutex_unlock(&led_cdev->led_access);
535 led_cdev->work_flags = 0;
536 #ifdef CONFIG_LEDS_TRIGGERS
537 init_rwsem(&led_cdev->trigger_lock);
539 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
540 led_cdev->brightness_hw_changed = -1;
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);
547 if (!led_cdev->max_brightness)
548 led_cdev->max_brightness = LED_FULL;
550 led_update_brightness(led_cdev);
552 led_init_core(led_cdev);
554 #ifdef CONFIG_LEDS_TRIGGERS
555 led_trigger_set_default(led_cdev);
558 mutex_unlock(&led_cdev->led_access);
560 dev_dbg(parent, "Registered led device: %s\n",
565 EXPORT_SYMBOL_GPL(led_classdev_register_ext);
568 * led_classdev_unregister - unregisters a object of led_properties class.
569 * @led_cdev: the led device to unregister
571 * Unregisters a previously registered via led_classdev_register object.
573 void led_classdev_unregister(struct led_classdev *led_cdev)
575 if (IS_ERR_OR_NULL(led_cdev->dev))
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);
585 led_cdev->flags |= LED_UNREGISTERING;
588 led_stop_software_blink(led_cdev);
590 if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
591 led_set_brightness(led_cdev, LED_OFF);
593 flush_work(&led_cdev->set_brightness_work);
595 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
596 led_remove_brightness_hw_changed(led_cdev);
598 device_unregister(led_cdev->dev);
600 down_write(&leds_list_lock);
601 list_del(&led_cdev->node);
602 up_write(&leds_list_lock);
604 mutex_destroy(&led_cdev->led_access);
606 EXPORT_SYMBOL_GPL(led_classdev_unregister);
608 static void devm_led_classdev_release(struct device *dev, void *res)
610 led_classdev_unregister(*(struct led_classdev **)res);
614 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
616 * @parent: parent of LED device
617 * @led_cdev: the led_classdev structure for this device.
618 * @init_data: LED class device initialization data
620 int devm_led_classdev_register_ext(struct device *parent,
621 struct led_classdev *led_cdev,
622 struct led_init_data *init_data)
624 struct led_classdev **dr;
627 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
631 rc = led_classdev_register_ext(parent, led_cdev, init_data);
638 devres_add(parent, dr);
642 EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
644 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
646 struct led_classdev **p = res;
648 if (WARN_ON(!p || !*p))
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.
659 void devm_led_classdev_unregister(struct device *dev,
660 struct led_classdev *led_cdev)
662 WARN_ON(devres_release(dev,
663 devm_led_classdev_release,
664 devm_led_classdev_match, led_cdev));
666 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
668 static int __init leds_init(void)
670 return class_register(&leds_class);
673 static void __exit leds_exit(void)
675 class_unregister(&leds_class);
678 subsys_initcall(leds_init);
679 module_exit(leds_exit);
681 MODULE_AUTHOR("John Lenz, Richard Purdie");
682 MODULE_LICENSE("GPL");
683 MODULE_DESCRIPTION("LED Class Interface");