Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.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 static void led_timer_function(unsigned long data)
106 {
107         struct led_classdev *led_cdev = (void *)data;
108         unsigned long brightness;
109         unsigned long delay;
110
111         if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
112                 led_set_brightness_async(led_cdev, LED_OFF);
113                 return;
114         }
115
116         if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
117                 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
118                 return;
119         }
120
121         brightness = led_get_brightness(led_cdev);
122         if (!brightness) {
123                 /* Time to switch the LED on. */
124                 brightness = led_cdev->blink_brightness;
125                 delay = led_cdev->blink_delay_on;
126         } else {
127                 /* Store the current brightness value to be able
128                  * to restore it when the delay_off period is over.
129                  */
130                 led_cdev->blink_brightness = brightness;
131                 brightness = LED_OFF;
132                 delay = led_cdev->blink_delay_off;
133         }
134
135         led_set_brightness_async(led_cdev, brightness);
136
137         /* Return in next iteration if led is in one-shot mode and we are in
138          * the final blink state so that the led is toggled each delay_on +
139          * delay_off milliseconds in worst case.
140          */
141         if (led_cdev->flags & LED_BLINK_ONESHOT) {
142                 if (led_cdev->flags & LED_BLINK_INVERT) {
143                         if (brightness)
144                                 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
145                 } else {
146                         if (!brightness)
147                                 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
148                 }
149         }
150
151         mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
152 }
153
154 static void set_brightness_delayed(struct work_struct *ws)
155 {
156         struct led_classdev *led_cdev =
157                 container_of(ws, struct led_classdev, set_brightness_work);
158
159         led_stop_software_blink(led_cdev);
160
161         led_set_brightness_async(led_cdev, led_cdev->delayed_set_value);
162 }
163
164 /**
165  * led_classdev_suspend - suspend an led_classdev.
166  * @led_cdev: the led_classdev to suspend.
167  */
168 void led_classdev_suspend(struct led_classdev *led_cdev)
169 {
170         led_cdev->flags |= LED_SUSPENDED;
171         led_cdev->brightness_set(led_cdev, 0);
172 }
173 EXPORT_SYMBOL_GPL(led_classdev_suspend);
174
175 /**
176  * led_classdev_resume - resume an led_classdev.
177  * @led_cdev: the led_classdev to resume.
178  */
179 void led_classdev_resume(struct led_classdev *led_cdev)
180 {
181         led_cdev->brightness_set(led_cdev, led_cdev->brightness);
182
183         if (led_cdev->flash_resume)
184                 led_cdev->flash_resume(led_cdev);
185
186         led_cdev->flags &= ~LED_SUSPENDED;
187 }
188 EXPORT_SYMBOL_GPL(led_classdev_resume);
189
190 static int led_suspend(struct device *dev)
191 {
192         struct led_classdev *led_cdev = dev_get_drvdata(dev);
193
194         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
195                 led_classdev_suspend(led_cdev);
196
197         return 0;
198 }
199
200 static int led_resume(struct device *dev)
201 {
202         struct led_classdev *led_cdev = dev_get_drvdata(dev);
203
204         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
205                 led_classdev_resume(led_cdev);
206
207         return 0;
208 }
209
210 static const struct dev_pm_ops leds_class_dev_pm_ops = {
211         .suspend        = led_suspend,
212         .resume         = led_resume,
213 };
214
215 static int match_name(struct device *dev, const void *data)
216 {
217         if (!dev_name(dev))
218                 return 0;
219         return !strcmp(dev_name(dev), (char *)data);
220 }
221
222 static int led_classdev_next_name(const char *init_name, char *name,
223                                   size_t len)
224 {
225         unsigned int i = 0;
226         int ret = 0;
227
228         strlcpy(name, init_name, len);
229
230         while (class_find_device(leds_class, NULL, name, match_name) &&
231                (ret < len))
232                 ret = snprintf(name, len, "%s_%u", init_name, ++i);
233
234         if (ret >= len)
235                 return -ENOMEM;
236
237         return i;
238 }
239
240 /**
241  * led_classdev_register - register a new object of led_classdev class.
242  * @parent: The device to register.
243  * @led_cdev: the led_classdev structure for this device.
244  */
245 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
246 {
247         char name[64];
248         int ret;
249
250         ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
251         if (ret < 0)
252                 return ret;
253
254         led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
255                                 led_cdev, led_cdev->groups, "%s", name);
256         if (IS_ERR(led_cdev->dev))
257                 return PTR_ERR(led_cdev->dev);
258
259         if (ret)
260                 dev_warn(parent, "Led %s renamed to %s due to name collision",
261                                 led_cdev->name, dev_name(led_cdev->dev));
262
263 #ifdef CONFIG_LEDS_TRIGGERS
264         init_rwsem(&led_cdev->trigger_lock);
265 #endif
266         mutex_init(&led_cdev->led_access);
267         /* add to the list of leds */
268         down_write(&leds_list_lock);
269         list_add_tail(&led_cdev->node, &leds_list);
270         up_write(&leds_list_lock);
271
272         if (!led_cdev->max_brightness)
273                 led_cdev->max_brightness = LED_FULL;
274
275         led_cdev->flags |= SET_BRIGHTNESS_ASYNC;
276
277         led_update_brightness(led_cdev);
278
279         INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
280
281         setup_timer(&led_cdev->blink_timer, led_timer_function,
282                     (unsigned long)led_cdev);
283
284 #ifdef CONFIG_LEDS_TRIGGERS
285         led_trigger_set_default(led_cdev);
286 #endif
287
288         dev_dbg(parent, "Registered led device: %s\n",
289                         led_cdev->name);
290
291         return 0;
292 }
293 EXPORT_SYMBOL_GPL(led_classdev_register);
294
295 /**
296  * led_classdev_unregister - unregisters a object of led_properties class.
297  * @led_cdev: the led device to unregister
298  *
299  * Unregisters a previously registered via led_classdev_register object.
300  */
301 void led_classdev_unregister(struct led_classdev *led_cdev)
302 {
303 #ifdef CONFIG_LEDS_TRIGGERS
304         down_write(&led_cdev->trigger_lock);
305         if (led_cdev->trigger)
306                 led_trigger_set(led_cdev, NULL);
307         up_write(&led_cdev->trigger_lock);
308 #endif
309
310         cancel_work_sync(&led_cdev->set_brightness_work);
311
312         /* Stop blinking */
313         led_stop_software_blink(led_cdev);
314         led_set_brightness(led_cdev, LED_OFF);
315
316         device_unregister(led_cdev->dev);
317
318         down_write(&leds_list_lock);
319         list_del(&led_cdev->node);
320         up_write(&leds_list_lock);
321
322         mutex_destroy(&led_cdev->led_access);
323 }
324 EXPORT_SYMBOL_GPL(led_classdev_unregister);
325
326 static void devm_led_classdev_release(struct device *dev, void *res)
327 {
328         led_classdev_unregister(*(struct led_classdev **)res);
329 }
330
331 /**
332  * devm_led_classdev_register - resource managed led_classdev_register()
333  * @parent: The device to register.
334  * @led_cdev: the led_classdev structure for this device.
335  */
336 int devm_led_classdev_register(struct device *parent,
337                                struct led_classdev *led_cdev)
338 {
339         struct led_classdev **dr;
340         int rc;
341
342         dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
343         if (!dr)
344                 return -ENOMEM;
345
346         rc = led_classdev_register(parent, led_cdev);
347         if (rc) {
348                 devres_free(dr);
349                 return rc;
350         }
351
352         *dr = led_cdev;
353         devres_add(parent, dr);
354
355         return 0;
356 }
357 EXPORT_SYMBOL_GPL(devm_led_classdev_register);
358
359 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
360 {
361         struct led_cdev **p = res;
362
363         if (WARN_ON(!p || !*p))
364                 return 0;
365
366         return *p == data;
367 }
368
369 /**
370  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
371  * @parent: The device to unregister.
372  * @led_cdev: the led_classdev structure for this device.
373  */
374 void devm_led_classdev_unregister(struct device *dev,
375                                   struct led_classdev *led_cdev)
376 {
377         WARN_ON(devres_release(dev,
378                                devm_led_classdev_release,
379                                devm_led_classdev_match, led_cdev));
380 }
381 EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
382
383 static int __init leds_init(void)
384 {
385         leds_class = class_create(THIS_MODULE, "leds");
386         if (IS_ERR(leds_class))
387                 return PTR_ERR(leds_class);
388         leds_class->pm = &leds_class_dev_pm_ops;
389         leds_class->dev_groups = led_groups;
390         return 0;
391 }
392
393 static void __exit leds_exit(void)
394 {
395         class_destroy(leds_class);
396 }
397
398 subsys_initcall(leds_init);
399 module_exit(leds_exit);
400
401 MODULE_AUTHOR("John Lenz, Richard Purdie");
402 MODULE_LICENSE("GPL");
403 MODULE_DESCRIPTION("LED Class Interface");