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 struct class *leds_class;
27 static ssize_t brightness_show(struct device *dev,
28 struct device_attribute *attr, char *buf)
30 struct led_classdev *led_cdev = dev_get_drvdata(dev);
32 /* no lock needed for this */
33 led_update_brightness(led_cdev);
35 return sprintf(buf, "%u\n", led_cdev->brightness);
38 static ssize_t brightness_store(struct device *dev,
39 struct device_attribute *attr, const char *buf, size_t size)
41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
45 mutex_lock(&led_cdev->led_access);
47 if (led_sysfs_is_disabled(led_cdev)) {
52 ret = kstrtoul(buf, 10, &state);
57 led_trigger_remove(led_cdev);
58 led_set_brightness(led_cdev, state);
59 flush_work(&led_cdev->set_brightness_work);
63 mutex_unlock(&led_cdev->led_access);
66 static DEVICE_ATTR_RW(brightness);
68 static ssize_t max_brightness_show(struct device *dev,
69 struct device_attribute *attr, char *buf)
71 struct led_classdev *led_cdev = dev_get_drvdata(dev);
73 return sprintf(buf, "%u\n", led_cdev->max_brightness);
75 static DEVICE_ATTR_RO(max_brightness);
77 #ifdef CONFIG_LEDS_TRIGGERS
78 static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
79 static struct bin_attribute *led_trigger_bin_attrs[] = {
83 static const struct attribute_group led_trigger_group = {
84 .bin_attrs = led_trigger_bin_attrs,
88 static struct attribute *led_class_attrs[] = {
89 &dev_attr_brightness.attr,
90 &dev_attr_max_brightness.attr,
94 static const struct attribute_group led_group = {
95 .attrs = led_class_attrs,
98 static const struct attribute_group *led_groups[] = {
100 #ifdef CONFIG_LEDS_TRIGGERS
106 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
107 static ssize_t brightness_hw_changed_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
110 struct led_classdev *led_cdev = dev_get_drvdata(dev);
112 if (led_cdev->brightness_hw_changed == -1)
115 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
118 static DEVICE_ATTR_RO(brightness_hw_changed);
120 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
122 struct device *dev = led_cdev->dev;
125 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
127 dev_err(dev, "Error creating brightness_hw_changed\n");
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);
142 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
144 sysfs_put(led_cdev->brightness_hw_changed_kn);
145 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
148 void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
150 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
153 led_cdev->brightness_hw_changed = brightness;
154 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
156 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
158 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
162 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
168 * led_classdev_suspend - suspend an led_classdev.
169 * @led_cdev: the led_classdev to suspend.
171 void led_classdev_suspend(struct led_classdev *led_cdev)
173 led_cdev->flags |= LED_SUSPENDED;
174 led_set_brightness_nopm(led_cdev, 0);
175 flush_work(&led_cdev->set_brightness_work);
177 EXPORT_SYMBOL_GPL(led_classdev_suspend);
180 * led_classdev_resume - resume an led_classdev.
181 * @led_cdev: the led_classdev to resume.
183 void led_classdev_resume(struct led_classdev *led_cdev)
185 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
187 if (led_cdev->flash_resume)
188 led_cdev->flash_resume(led_cdev);
190 led_cdev->flags &= ~LED_SUSPENDED;
192 EXPORT_SYMBOL_GPL(led_classdev_resume);
194 #ifdef CONFIG_PM_SLEEP
195 static int led_suspend(struct device *dev)
197 struct led_classdev *led_cdev = dev_get_drvdata(dev);
199 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
200 led_classdev_suspend(led_cdev);
205 static int led_resume(struct device *dev)
207 struct led_classdev *led_cdev = dev_get_drvdata(dev);
209 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
210 led_classdev_resume(led_cdev);
216 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
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
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.
226 struct led_classdev *of_led_get(struct device_node *np, int index)
228 struct device *led_dev;
229 struct led_classdev *led_cdev;
230 struct device_node *led_node;
232 led_node = of_parse_phandle(np, "leds", index);
234 return ERR_PTR(-ENOENT);
236 led_dev = class_find_device_by_of_node(leds_class, led_node);
237 of_node_put(led_node);
241 return ERR_PTR(-EPROBE_DEFER);
243 led_cdev = dev_get_drvdata(led_dev);
245 if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
246 put_device(led_cdev->dev);
247 return ERR_PTR(-ENODEV);
252 EXPORT_SYMBOL_GPL(of_led_get);
255 * led_put() - release a LED device
256 * @led_cdev: LED device
258 void led_put(struct led_classdev *led_cdev)
260 module_put(led_cdev->dev->parent->driver->owner);
261 put_device(led_cdev->dev);
263 EXPORT_SYMBOL_GPL(led_put);
265 static void devm_led_release(struct device *dev, void *res)
267 struct led_classdev **p = res;
273 * devm_of_led_get - Resource-managed request of a LED device
275 * @index: index of the LED to obtain in the consumer
277 * The device node of the device is parse to find the request LED device.
278 * The LED device returned from this function is automatically released
281 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
283 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
286 struct led_classdev *led;
287 struct led_classdev **dr;
290 return ERR_PTR(-EINVAL);
292 led = of_led_get(dev->of_node, index);
296 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
300 return ERR_PTR(-ENOMEM);
308 EXPORT_SYMBOL_GPL(devm_of_led_get);
310 static int led_classdev_next_name(const char *init_name, char *name,
317 strlcpy(name, init_name, len);
319 while ((ret < len) &&
320 (dev = class_find_device_by_name(leds_class, name))) {
322 ret = snprintf(name, len, "%s_%u", init_name, ++i);
332 * led_classdev_register_ext - register a new object of led_classdev class
335 * @parent: parent of LED device
336 * @led_cdev: the led_classdev structure for this device.
337 * @init_data: LED class device initialization data
339 int led_classdev_register_ext(struct device *parent,
340 struct led_classdev *led_cdev,
341 struct led_init_data *init_data)
343 char composed_name[LED_MAX_NAME_SIZE];
344 char final_name[LED_MAX_NAME_SIZE];
345 const char *proposed_name = composed_name;
349 if (init_data->devname_mandatory && !init_data->devicename) {
350 dev_err(parent, "Mandatory device name is missing");
353 ret = led_compose_name(parent, init_data, composed_name);
357 if (init_data->fwnode) {
358 fwnode_property_read_string(init_data->fwnode,
359 "linux,default-trigger",
360 &led_cdev->default_trigger);
362 if (fwnode_property_present(init_data->fwnode,
363 "retain-state-shutdown"))
364 led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
367 proposed_name = led_cdev->name;
370 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
374 mutex_init(&led_cdev->led_access);
375 mutex_lock(&led_cdev->led_access);
376 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
377 led_cdev, led_cdev->groups, "%s", final_name);
378 if (IS_ERR(led_cdev->dev)) {
379 mutex_unlock(&led_cdev->led_access);
380 return PTR_ERR(led_cdev->dev);
382 if (init_data && init_data->fwnode)
383 device_set_node(led_cdev->dev, init_data->fwnode);
386 dev_warn(parent, "Led %s renamed to %s due to name collision",
387 proposed_name, dev_name(led_cdev->dev));
389 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
390 ret = led_add_brightness_hw_changed(led_cdev);
392 device_unregister(led_cdev->dev);
393 led_cdev->dev = NULL;
394 mutex_unlock(&led_cdev->led_access);
399 led_cdev->work_flags = 0;
400 #ifdef CONFIG_LEDS_TRIGGERS
401 init_rwsem(&led_cdev->trigger_lock);
403 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
404 led_cdev->brightness_hw_changed = -1;
406 /* add to the list of leds */
407 down_write(&leds_list_lock);
408 list_add_tail(&led_cdev->node, &leds_list);
409 up_write(&leds_list_lock);
411 if (!led_cdev->max_brightness)
412 led_cdev->max_brightness = LED_FULL;
414 led_update_brightness(led_cdev);
416 led_init_core(led_cdev);
418 #ifdef CONFIG_LEDS_TRIGGERS
419 led_trigger_set_default(led_cdev);
422 mutex_unlock(&led_cdev->led_access);
424 dev_dbg(parent, "Registered led device: %s\n",
429 EXPORT_SYMBOL_GPL(led_classdev_register_ext);
432 * led_classdev_unregister - unregisters a object of led_properties class.
433 * @led_cdev: the led device to unregister
435 * Unregisters a previously registered via led_classdev_register object.
437 void led_classdev_unregister(struct led_classdev *led_cdev)
439 if (IS_ERR_OR_NULL(led_cdev->dev))
442 #ifdef CONFIG_LEDS_TRIGGERS
443 down_write(&led_cdev->trigger_lock);
444 if (led_cdev->trigger)
445 led_trigger_set(led_cdev, NULL);
446 up_write(&led_cdev->trigger_lock);
449 led_cdev->flags |= LED_UNREGISTERING;
452 led_stop_software_blink(led_cdev);
454 if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
455 led_set_brightness(led_cdev, LED_OFF);
457 flush_work(&led_cdev->set_brightness_work);
459 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
460 led_remove_brightness_hw_changed(led_cdev);
462 device_unregister(led_cdev->dev);
464 down_write(&leds_list_lock);
465 list_del(&led_cdev->node);
466 up_write(&leds_list_lock);
468 mutex_destroy(&led_cdev->led_access);
470 EXPORT_SYMBOL_GPL(led_classdev_unregister);
472 static void devm_led_classdev_release(struct device *dev, void *res)
474 led_classdev_unregister(*(struct led_classdev **)res);
478 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
480 * @parent: parent of LED device
481 * @led_cdev: the led_classdev structure for this device.
482 * @init_data: LED class device initialization data
484 int devm_led_classdev_register_ext(struct device *parent,
485 struct led_classdev *led_cdev,
486 struct led_init_data *init_data)
488 struct led_classdev **dr;
491 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
495 rc = led_classdev_register_ext(parent, led_cdev, init_data);
502 devres_add(parent, dr);
506 EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
508 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
510 struct led_classdev **p = res;
512 if (WARN_ON(!p || !*p))
519 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
520 * @dev: The device to unregister.
521 * @led_cdev: the led_classdev structure for this device.
523 void devm_led_classdev_unregister(struct device *dev,
524 struct led_classdev *led_cdev)
526 WARN_ON(devres_release(dev,
527 devm_led_classdev_release,
528 devm_led_classdev_match, led_cdev));
530 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
532 static int __init leds_init(void)
534 leds_class = class_create(THIS_MODULE, "leds");
535 if (IS_ERR(leds_class))
536 return PTR_ERR(leds_class);
537 leds_class->pm = &leds_class_dev_pm_ops;
538 leds_class->dev_groups = led_groups;
542 static void __exit leds_exit(void)
544 class_destroy(leds_class);
547 subsys_initcall(leds_init);
548 module_exit(leds_exit);
550 MODULE_AUTHOR("John Lenz, Richard Purdie");
551 MODULE_LICENSE("GPL");
552 MODULE_DESCRIPTION("LED Class Interface");