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Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[karo-tx-linux.git] / drivers / leds / led-class.c
1 /*
2  * LED Class Core
3  *
4  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5  * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6  *
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.
10  */
11
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 "leds.h"
24
25 static struct class *leds_class;
26
27 static 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
38 static 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
60         ret = size;
61 unlock:
62         mutex_unlock(&led_cdev->led_access);
63         return ret;
64 }
65 static DEVICE_ATTR_RW(brightness);
66
67 static ssize_t max_brightness_show(struct device *dev,
68                 struct device_attribute *attr, char *buf)
69 {
70         struct led_classdev *led_cdev = dev_get_drvdata(dev);
71
72         return sprintf(buf, "%u\n", led_cdev->max_brightness);
73 }
74 static DEVICE_ATTR_RO(max_brightness);
75
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,
80         NULL,
81 };
82 static const struct attribute_group led_trigger_group = {
83         .attrs = led_trigger_attrs,
84 };
85 #endif
86
87 static struct attribute *led_class_attrs[] = {
88         &dev_attr_brightness.attr,
89         &dev_attr_max_brightness.attr,
90         NULL,
91 };
92
93 static const struct attribute_group led_group = {
94         .attrs = led_class_attrs,
95 };
96
97 static const struct attribute_group *led_groups[] = {
98         &led_group,
99 #ifdef CONFIG_LEDS_TRIGGERS
100         &led_trigger_group,
101 #endif
102         NULL,
103 };
104
105 /**
106  * led_classdev_suspend - suspend an led_classdev.
107  * @led_cdev: the led_classdev to suspend.
108  */
109 void led_classdev_suspend(struct led_classdev *led_cdev)
110 {
111         led_cdev->flags |= LED_SUSPENDED;
112         led_set_brightness_nopm(led_cdev, 0);
113 }
114 EXPORT_SYMBOL_GPL(led_classdev_suspend);
115
116 /**
117  * led_classdev_resume - resume an led_classdev.
118  * @led_cdev: the led_classdev to resume.
119  */
120 void led_classdev_resume(struct led_classdev *led_cdev)
121 {
122         led_set_brightness_nopm(led_cdev, led_cdev->brightness);
123
124         if (led_cdev->flash_resume)
125                 led_cdev->flash_resume(led_cdev);
126
127         led_cdev->flags &= ~LED_SUSPENDED;
128 }
129 EXPORT_SYMBOL_GPL(led_classdev_resume);
130
131 #ifdef CONFIG_PM_SLEEP
132 static int led_suspend(struct device *dev)
133 {
134         struct led_classdev *led_cdev = dev_get_drvdata(dev);
135
136         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
137                 led_classdev_suspend(led_cdev);
138
139         return 0;
140 }
141
142 static int led_resume(struct device *dev)
143 {
144         struct led_classdev *led_cdev = dev_get_drvdata(dev);
145
146         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
147                 led_classdev_resume(led_cdev);
148
149         return 0;
150 }
151 #endif
152
153 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
154
155 static int match_name(struct device *dev, const void *data)
156 {
157         if (!dev_name(dev))
158                 return 0;
159         return !strcmp(dev_name(dev), (char *)data);
160 }
161
162 static int led_classdev_next_name(const char *init_name, char *name,
163                                   size_t len)
164 {
165         unsigned int i = 0;
166         int ret = 0;
167         struct device *dev;
168
169         strlcpy(name, init_name, len);
170
171         while ((ret < len) &&
172                (dev = class_find_device(leds_class, NULL, name, match_name))) {
173                 put_device(dev);
174                 ret = snprintf(name, len, "%s_%u", init_name, ++i);
175         }
176
177         if (ret >= len)
178                 return -ENOMEM;
179
180         return i;
181 }
182
183 /**
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.
187  */
188 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
189 {
190         char name[64];
191         int ret;
192
193         ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
194         if (ret < 0)
195                 return ret;
196
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);
201
202         if (ret)
203                 dev_warn(parent, "Led %s renamed to %s due to name collision",
204                                 led_cdev->name, dev_name(led_cdev->dev));
205
206 #ifdef CONFIG_LEDS_TRIGGERS
207         init_rwsem(&led_cdev->trigger_lock);
208 #endif
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);
214
215         if (!led_cdev->max_brightness)
216                 led_cdev->max_brightness = LED_FULL;
217
218         led_update_brightness(led_cdev);
219
220         led_init_core(led_cdev);
221
222 #ifdef CONFIG_LEDS_TRIGGERS
223         led_trigger_set_default(led_cdev);
224 #endif
225
226         dev_dbg(parent, "Registered led device: %s\n",
227                         led_cdev->name);
228
229         return 0;
230 }
231 EXPORT_SYMBOL_GPL(led_classdev_register);
232
233 /**
234  * led_classdev_unregister - unregisters a object of led_properties class.
235  * @led_cdev: the led device to unregister
236  *
237  * Unregisters a previously registered via led_classdev_register object.
238  */
239 void led_classdev_unregister(struct led_classdev *led_cdev)
240 {
241 #ifdef CONFIG_LEDS_TRIGGERS
242         down_write(&led_cdev->trigger_lock);
243         if (led_cdev->trigger)
244                 led_trigger_set(led_cdev, NULL);
245         up_write(&led_cdev->trigger_lock);
246 #endif
247
248         led_cdev->flags |= LED_UNREGISTERING;
249
250         /* Stop blinking */
251         led_stop_software_blink(led_cdev);
252
253         led_set_brightness(led_cdev, LED_OFF);
254
255         flush_work(&led_cdev->set_brightness_work);
256
257         device_unregister(led_cdev->dev);
258
259         down_write(&leds_list_lock);
260         list_del(&led_cdev->node);
261         up_write(&leds_list_lock);
262
263         mutex_destroy(&led_cdev->led_access);
264 }
265 EXPORT_SYMBOL_GPL(led_classdev_unregister);
266
267 static void devm_led_classdev_release(struct device *dev, void *res)
268 {
269         led_classdev_unregister(*(struct led_classdev **)res);
270 }
271
272 /**
273  * devm_led_classdev_register - resource managed led_classdev_register()
274  * @parent: The device to register.
275  * @led_cdev: the led_classdev structure for this device.
276  */
277 int devm_led_classdev_register(struct device *parent,
278                                struct led_classdev *led_cdev)
279 {
280         struct led_classdev **dr;
281         int rc;
282
283         dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
284         if (!dr)
285                 return -ENOMEM;
286
287         rc = led_classdev_register(parent, led_cdev);
288         if (rc) {
289                 devres_free(dr);
290                 return rc;
291         }
292
293         *dr = led_cdev;
294         devres_add(parent, dr);
295
296         return 0;
297 }
298 EXPORT_SYMBOL_GPL(devm_led_classdev_register);
299
300 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
301 {
302         struct led_cdev **p = res;
303
304         if (WARN_ON(!p || !*p))
305                 return 0;
306
307         return *p == data;
308 }
309
310 /**
311  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
312  * @parent: The device to unregister.
313  * @led_cdev: the led_classdev structure for this device.
314  */
315 void devm_led_classdev_unregister(struct device *dev,
316                                   struct led_classdev *led_cdev)
317 {
318         WARN_ON(devres_release(dev,
319                                devm_led_classdev_release,
320                                devm_led_classdev_match, led_cdev));
321 }
322 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
323
324 static int __init leds_init(void)
325 {
326         leds_class = class_create(THIS_MODULE, "leds");
327         if (IS_ERR(leds_class))
328                 return PTR_ERR(leds_class);
329         leds_class->pm = &leds_class_dev_pm_ops;
330         leds_class->dev_groups = led_groups;
331         return 0;
332 }
333
334 static void __exit leds_exit(void)
335 {
336         class_destroy(leds_class);
337 }
338
339 subsys_initcall(leds_init);
340 module_exit(leds_exit);
341
342 MODULE_AUTHOR("John Lenz, Richard Purdie");
343 MODULE_LICENSE("GPL");
344 MODULE_DESCRIPTION("LED Class Interface");