4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/ctype.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/leds.h>
18 #include <linux/list.h>
19 #include <linux/module.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/timer.h>
23 #include <uapi/linux/uleds.h>
26 static struct class *leds_class;
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 DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
80 static struct attribute *led_trigger_attrs[] = {
81 &dev_attr_trigger.attr,
84 static const struct attribute_group led_trigger_group = {
85 .attrs = led_trigger_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,
150 enum led_brightness brightness)
152 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
155 led_cdev->brightness_hw_changed = brightness;
156 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
158 EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
160 static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
164 static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
170 * led_classdev_suspend - suspend an led_classdev.
171 * @led_cdev: the led_classdev to suspend.
173 void led_classdev_suspend(struct led_classdev *led_cdev)
175 led_cdev->flags |= LED_SUSPENDED;
176 led_set_brightness_nopm(led_cdev, 0);
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 int match_name(struct device *dev, const void *data)
223 return !strcmp(dev_name(dev), (char *)data);
226 static int led_classdev_next_name(const char *init_name, char *name,
233 strlcpy(name, init_name, len);
235 while ((ret < len) &&
236 (dev = class_find_device(leds_class, NULL, name, match_name))) {
238 ret = snprintf(name, len, "%s_%u", init_name, ++i);
248 * of_led_classdev_register - register a new object of led_classdev class.
250 * @parent: parent of LED device
251 * @led_cdev: the led_classdev structure for this device.
252 * @np: DT node describing this LED
254 int of_led_classdev_register(struct device *parent, struct device_node *np,
255 struct led_classdev *led_cdev)
257 char name[LED_MAX_NAME_SIZE];
260 ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
264 mutex_init(&led_cdev->led_access);
265 mutex_lock(&led_cdev->led_access);
266 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
267 led_cdev, led_cdev->groups, "%s", name);
268 if (IS_ERR(led_cdev->dev)) {
269 mutex_unlock(&led_cdev->led_access);
270 return PTR_ERR(led_cdev->dev);
272 led_cdev->dev->of_node = np;
275 dev_warn(parent, "Led %s renamed to %s due to name collision",
276 led_cdev->name, dev_name(led_cdev->dev));
278 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
279 ret = led_add_brightness_hw_changed(led_cdev);
281 device_unregister(led_cdev->dev);
282 mutex_unlock(&led_cdev->led_access);
287 led_cdev->work_flags = 0;
288 #ifdef CONFIG_LEDS_TRIGGERS
289 init_rwsem(&led_cdev->trigger_lock);
291 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
292 led_cdev->brightness_hw_changed = -1;
294 /* add to the list of leds */
295 down_write(&leds_list_lock);
296 list_add_tail(&led_cdev->node, &leds_list);
297 up_write(&leds_list_lock);
299 if (!led_cdev->max_brightness)
300 led_cdev->max_brightness = LED_FULL;
302 led_update_brightness(led_cdev);
304 led_init_core(led_cdev);
306 #ifdef CONFIG_LEDS_TRIGGERS
307 led_trigger_set_default(led_cdev);
310 mutex_unlock(&led_cdev->led_access);
312 dev_dbg(parent, "Registered led device: %s\n",
317 EXPORT_SYMBOL_GPL(of_led_classdev_register);
320 * led_classdev_unregister - unregisters a object of led_properties class.
321 * @led_cdev: the led device to unregister
323 * Unregisters a previously registered via led_classdev_register object.
325 void led_classdev_unregister(struct led_classdev *led_cdev)
327 #ifdef CONFIG_LEDS_TRIGGERS
328 down_write(&led_cdev->trigger_lock);
329 if (led_cdev->trigger)
330 led_trigger_set(led_cdev, NULL);
331 up_write(&led_cdev->trigger_lock);
334 led_cdev->flags |= LED_UNREGISTERING;
337 led_stop_software_blink(led_cdev);
339 led_set_brightness(led_cdev, LED_OFF);
341 flush_work(&led_cdev->set_brightness_work);
343 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
344 led_remove_brightness_hw_changed(led_cdev);
346 device_unregister(led_cdev->dev);
348 down_write(&leds_list_lock);
349 list_del(&led_cdev->node);
350 up_write(&leds_list_lock);
352 mutex_destroy(&led_cdev->led_access);
354 EXPORT_SYMBOL_GPL(led_classdev_unregister);
356 static void devm_led_classdev_release(struct device *dev, void *res)
358 led_classdev_unregister(*(struct led_classdev **)res);
362 * devm_of_led_classdev_register - resource managed led_classdev_register()
364 * @parent: parent of LED device
365 * @led_cdev: the led_classdev structure for this device.
367 int devm_of_led_classdev_register(struct device *parent,
368 struct device_node *np,
369 struct led_classdev *led_cdev)
371 struct led_classdev **dr;
374 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
378 rc = of_led_classdev_register(parent, np, led_cdev);
385 devres_add(parent, dr);
389 EXPORT_SYMBOL_GPL(devm_of_led_classdev_register);
391 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
393 struct led_cdev **p = res;
395 if (WARN_ON(!p || !*p))
402 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
403 * @parent: The device to unregister.
404 * @led_cdev: the led_classdev structure for this device.
406 void devm_led_classdev_unregister(struct device *dev,
407 struct led_classdev *led_cdev)
409 WARN_ON(devres_release(dev,
410 devm_led_classdev_release,
411 devm_led_classdev_match, led_cdev));
413 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
415 static int __init leds_init(void)
417 leds_class = class_create(THIS_MODULE, "leds");
418 if (IS_ERR(leds_class))
419 return PTR_ERR(leds_class);
420 leds_class->pm = &leds_class_dev_pm_ops;
421 leds_class->dev_groups = led_groups;
425 static void __exit leds_exit(void)
427 class_destroy(leds_class);
430 subsys_initcall(leds_init);
431 module_exit(leds_exit);
433 MODULE_AUTHOR("John Lenz, Richard Purdie");
434 MODULE_LICENSE("GPL");
435 MODULE_DESCRIPTION("LED Class Interface");