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>
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);
62 mutex_unlock(&led_cdev->led_access);
65 static DEVICE_ATTR_RW(brightness);
67 static ssize_t max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
74 static DEVICE_ATTR_RO(max_brightness);
76 #ifdef CONFIG_LEDS_TRIGGERS
77 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
78 static struct attribute *led_trigger_attrs[] = {
79 &dev_attr_trigger.attr,
82 static const struct attribute_group led_trigger_group = {
83 .attrs = led_trigger_attrs,
87 static struct attribute *led_class_attrs[] = {
88 &dev_attr_brightness.attr,
89 &dev_attr_max_brightness.attr,
93 static const struct attribute_group led_group = {
94 .attrs = led_class_attrs,
97 static const struct attribute_group *led_groups[] = {
99 #ifdef CONFIG_LEDS_TRIGGERS
106 * led_classdev_suspend - suspend an led_classdev.
107 * @led_cdev: the led_classdev to suspend.
109 void led_classdev_suspend(struct led_classdev *led_cdev)
111 led_cdev->flags |= LED_SUSPENDED;
112 led_cdev->brightness_set(led_cdev, 0);
114 EXPORT_SYMBOL_GPL(led_classdev_suspend);
117 * led_classdev_resume - resume an led_classdev.
118 * @led_cdev: the led_classdev to resume.
120 void led_classdev_resume(struct led_classdev *led_cdev)
122 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
124 if (led_cdev->flash_resume)
125 led_cdev->flash_resume(led_cdev);
127 led_cdev->flags &= ~LED_SUSPENDED;
129 EXPORT_SYMBOL_GPL(led_classdev_resume);
131 #ifdef CONFIG_PM_SLEEP
132 static int led_suspend(struct device *dev)
134 struct led_classdev *led_cdev = dev_get_drvdata(dev);
136 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
137 led_classdev_suspend(led_cdev);
142 static int led_resume(struct device *dev)
144 struct led_classdev *led_cdev = dev_get_drvdata(dev);
146 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
147 led_classdev_resume(led_cdev);
153 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
155 static int match_name(struct device *dev, const void *data)
159 return !strcmp(dev_name(dev), (char *)data);
162 static int led_classdev_next_name(const char *init_name, char *name,
169 strlcpy(name, init_name, len);
171 while ((ret < len) &&
172 (dev = class_find_device(leds_class, NULL, name, match_name))) {
174 ret = snprintf(name, len, "%s_%u", init_name, ++i);
184 * led_classdev_register - register a new object of led_classdev class.
185 * @parent: The device to register.
186 * @led_cdev: the led_classdev structure for this device.
188 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
193 ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
197 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
198 led_cdev, led_cdev->groups, "%s", name);
199 if (IS_ERR(led_cdev->dev))
200 return PTR_ERR(led_cdev->dev);
203 dev_warn(parent, "Led %s renamed to %s due to name collision",
204 led_cdev->name, dev_name(led_cdev->dev));
206 #ifdef CONFIG_LEDS_TRIGGERS
207 init_rwsem(&led_cdev->trigger_lock);
209 mutex_init(&led_cdev->led_access);
210 /* add to the list of leds */
211 down_write(&leds_list_lock);
212 list_add_tail(&led_cdev->node, &leds_list);
213 up_write(&leds_list_lock);
215 if (!led_cdev->max_brightness)
216 led_cdev->max_brightness = LED_FULL;
218 led_cdev->flags |= SET_BRIGHTNESS_ASYNC;
220 led_update_brightness(led_cdev);
222 led_init_core(led_cdev);
224 #ifdef CONFIG_LEDS_TRIGGERS
225 led_trigger_set_default(led_cdev);
228 dev_dbg(parent, "Registered led device: %s\n",
233 EXPORT_SYMBOL_GPL(led_classdev_register);
236 * led_classdev_unregister - unregisters a object of led_properties class.
237 * @led_cdev: the led device to unregister
239 * Unregisters a previously registered via led_classdev_register object.
241 void led_classdev_unregister(struct led_classdev *led_cdev)
243 #ifdef CONFIG_LEDS_TRIGGERS
244 down_write(&led_cdev->trigger_lock);
245 if (led_cdev->trigger)
246 led_trigger_set(led_cdev, NULL);
247 up_write(&led_cdev->trigger_lock);
250 cancel_work_sync(&led_cdev->set_brightness_work);
253 led_stop_software_blink(led_cdev);
254 led_set_brightness(led_cdev, LED_OFF);
256 device_unregister(led_cdev->dev);
258 down_write(&leds_list_lock);
259 list_del(&led_cdev->node);
260 up_write(&leds_list_lock);
262 mutex_destroy(&led_cdev->led_access);
264 EXPORT_SYMBOL_GPL(led_classdev_unregister);
266 static void devm_led_classdev_release(struct device *dev, void *res)
268 led_classdev_unregister(*(struct led_classdev **)res);
272 * devm_led_classdev_register - resource managed led_classdev_register()
273 * @parent: The device to register.
274 * @led_cdev: the led_classdev structure for this device.
276 int devm_led_classdev_register(struct device *parent,
277 struct led_classdev *led_cdev)
279 struct led_classdev **dr;
282 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
286 rc = led_classdev_register(parent, led_cdev);
293 devres_add(parent, dr);
297 EXPORT_SYMBOL_GPL(devm_led_classdev_register);
299 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
301 struct led_cdev **p = res;
303 if (WARN_ON(!p || !*p))
310 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
311 * @parent: The device to unregister.
312 * @led_cdev: the led_classdev structure for this device.
314 void devm_led_classdev_unregister(struct device *dev,
315 struct led_classdev *led_cdev)
317 WARN_ON(devres_release(dev,
318 devm_led_classdev_release,
319 devm_led_classdev_match, led_cdev));
321 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
323 static int __init leds_init(void)
325 leds_class = class_create(THIS_MODULE, "leds");
326 if (IS_ERR(leds_class))
327 return PTR_ERR(leds_class);
328 leds_class->pm = &leds_class_dev_pm_ops;
329 leds_class->dev_groups = led_groups;
333 static void __exit leds_exit(void)
335 class_destroy(leds_class);
338 subsys_initcall(leds_init);
339 module_exit(leds_exit);
341 MODULE_AUTHOR("John Lenz, Richard Purdie");
342 MODULE_LICENSE("GPL");
343 MODULE_DESCRIPTION("LED Class Interface");