hwmon: (adt7411) add MODULE_DEVICE_TABLE
[linux-2.6.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/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/list.h>
16 #include <linux/spinlock.h>
17 #include <linux/device.h>
18 #include <linux/sysdev.h>
19 #include <linux/timer.h>
20 #include <linux/err.h>
21 #include <linux/ctype.h>
22 #include <linux/leds.h>
23 #include "leds.h"
24
25 static struct class *leds_class;
26
27 static void led_update_brightness(struct led_classdev *led_cdev)
28 {
29         if (led_cdev->brightness_get)
30                 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
31 }
32
33 static ssize_t led_brightness_show(struct device *dev, 
34                 struct device_attribute *attr, char *buf)
35 {
36         struct led_classdev *led_cdev = dev_get_drvdata(dev);
37
38         /* no lock needed for this */
39         led_update_brightness(led_cdev);
40
41         return sprintf(buf, "%u\n", led_cdev->brightness);
42 }
43
44 static ssize_t led_brightness_store(struct device *dev,
45                 struct device_attribute *attr, const char *buf, size_t size)
46 {
47         struct led_classdev *led_cdev = dev_get_drvdata(dev);
48         ssize_t ret = -EINVAL;
49         char *after;
50         unsigned long state = simple_strtoul(buf, &after, 10);
51         size_t count = after - buf;
52
53         if (isspace(*after))
54                 count++;
55
56         if (count == size) {
57                 ret = count;
58
59                 if (state == LED_OFF)
60                         led_trigger_remove(led_cdev);
61                 led_set_brightness(led_cdev, state);
62         }
63
64         return ret;
65 }
66
67 static ssize_t led_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
75 static struct device_attribute led_class_attrs[] = {
76         __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
77         __ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
78 #ifdef CONFIG_LEDS_TRIGGERS
79         __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
80 #endif
81         __ATTR_NULL,
82 };
83
84 static void led_timer_function(unsigned long data)
85 {
86         struct led_classdev *led_cdev = (void *)data;
87         unsigned long brightness;
88         unsigned long delay;
89
90         if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
91                 led_set_brightness(led_cdev, LED_OFF);
92                 return;
93         }
94
95         brightness = led_get_brightness(led_cdev);
96         if (!brightness) {
97                 /* Time to switch the LED on. */
98                 brightness = led_cdev->blink_brightness;
99                 delay = led_cdev->blink_delay_on;
100         } else {
101                 /* Store the current brightness value to be able
102                  * to restore it when the delay_off period is over.
103                  */
104                 led_cdev->blink_brightness = brightness;
105                 brightness = LED_OFF;
106                 delay = led_cdev->blink_delay_off;
107         }
108
109         led_set_brightness(led_cdev, brightness);
110
111         mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
112 }
113
114 static void led_stop_software_blink(struct led_classdev *led_cdev)
115 {
116         /* deactivate previous settings */
117         del_timer_sync(&led_cdev->blink_timer);
118         led_cdev->blink_delay_on = 0;
119         led_cdev->blink_delay_off = 0;
120 }
121
122 static void led_set_software_blink(struct led_classdev *led_cdev,
123                                    unsigned long delay_on,
124                                    unsigned long delay_off)
125 {
126         int current_brightness;
127
128         current_brightness = led_get_brightness(led_cdev);
129         if (current_brightness)
130                 led_cdev->blink_brightness = current_brightness;
131         if (!led_cdev->blink_brightness)
132                 led_cdev->blink_brightness = led_cdev->max_brightness;
133
134         if (delay_on == led_cdev->blink_delay_on &&
135             delay_off == led_cdev->blink_delay_off)
136                 return;
137
138         led_stop_software_blink(led_cdev);
139
140         led_cdev->blink_delay_on = delay_on;
141         led_cdev->blink_delay_off = delay_off;
142
143         /* never on - don't blink */
144         if (!delay_on)
145                 return;
146
147         /* never off - just set to brightness */
148         if (!delay_off) {
149                 led_set_brightness(led_cdev, led_cdev->blink_brightness);
150                 return;
151         }
152
153         mod_timer(&led_cdev->blink_timer, jiffies + 1);
154 }
155
156
157 /**
158  * led_classdev_suspend - suspend an led_classdev.
159  * @led_cdev: the led_classdev to suspend.
160  */
161 void led_classdev_suspend(struct led_classdev *led_cdev)
162 {
163         led_cdev->flags |= LED_SUSPENDED;
164         led_cdev->brightness_set(led_cdev, 0);
165 }
166 EXPORT_SYMBOL_GPL(led_classdev_suspend);
167
168 /**
169  * led_classdev_resume - resume an led_classdev.
170  * @led_cdev: the led_classdev to resume.
171  */
172 void led_classdev_resume(struct led_classdev *led_cdev)
173 {
174         led_cdev->brightness_set(led_cdev, led_cdev->brightness);
175         led_cdev->flags &= ~LED_SUSPENDED;
176 }
177 EXPORT_SYMBOL_GPL(led_classdev_resume);
178
179 static int led_suspend(struct device *dev, pm_message_t state)
180 {
181         struct led_classdev *led_cdev = dev_get_drvdata(dev);
182
183         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
184                 led_classdev_suspend(led_cdev);
185
186         return 0;
187 }
188
189 static int led_resume(struct device *dev)
190 {
191         struct led_classdev *led_cdev = dev_get_drvdata(dev);
192
193         if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
194                 led_classdev_resume(led_cdev);
195
196         return 0;
197 }
198
199 /**
200  * led_classdev_register - register a new object of led_classdev class.
201  * @parent: The device to register.
202  * @led_cdev: the led_classdev structure for this device.
203  */
204 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
205 {
206         led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
207                                       "%s", led_cdev->name);
208         if (IS_ERR(led_cdev->dev))
209                 return PTR_ERR(led_cdev->dev);
210
211 #ifdef CONFIG_LEDS_TRIGGERS
212         init_rwsem(&led_cdev->trigger_lock);
213 #endif
214         /* add to the list of leds */
215         down_write(&leds_list_lock);
216         list_add_tail(&led_cdev->node, &leds_list);
217         up_write(&leds_list_lock);
218
219         if (!led_cdev->max_brightness)
220                 led_cdev->max_brightness = LED_FULL;
221
222         led_update_brightness(led_cdev);
223
224         init_timer(&led_cdev->blink_timer);
225         led_cdev->blink_timer.function = led_timer_function;
226         led_cdev->blink_timer.data = (unsigned long)led_cdev;
227
228 #ifdef CONFIG_LEDS_TRIGGERS
229         led_trigger_set_default(led_cdev);
230 #endif
231
232         printk(KERN_DEBUG "Registered led device: %s\n",
233                         led_cdev->name);
234
235         return 0;
236 }
237 EXPORT_SYMBOL_GPL(led_classdev_register);
238
239 /**
240  * led_classdev_unregister - unregisters a object of led_properties class.
241  * @led_cdev: the led device to unregister
242  *
243  * Unregisters a previously registered via led_classdev_register object.
244  */
245 void led_classdev_unregister(struct led_classdev *led_cdev)
246 {
247 #ifdef CONFIG_LEDS_TRIGGERS
248         down_write(&led_cdev->trigger_lock);
249         if (led_cdev->trigger)
250                 led_trigger_set(led_cdev, NULL);
251         up_write(&led_cdev->trigger_lock);
252 #endif
253
254         /* Stop blinking */
255         led_brightness_set(led_cdev, LED_OFF);
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 EXPORT_SYMBOL_GPL(led_classdev_unregister);
264
265 void led_blink_set(struct led_classdev *led_cdev,
266                    unsigned long *delay_on,
267                    unsigned long *delay_off)
268 {
269         if (led_cdev->blink_set &&
270             !led_cdev->blink_set(led_cdev, delay_on, delay_off))
271                 return;
272
273         /* blink with 1 Hz as default if nothing specified */
274         if (!*delay_on && !*delay_off)
275                 *delay_on = *delay_off = 500;
276
277         led_set_software_blink(led_cdev, *delay_on, *delay_off);
278 }
279 EXPORT_SYMBOL(led_blink_set);
280
281 void led_brightness_set(struct led_classdev *led_cdev,
282                         enum led_brightness brightness)
283 {
284         led_stop_software_blink(led_cdev);
285         led_cdev->brightness_set(led_cdev, brightness);
286 }
287 EXPORT_SYMBOL(led_brightness_set);
288
289 static int __init leds_init(void)
290 {
291         leds_class = class_create(THIS_MODULE, "leds");
292         if (IS_ERR(leds_class))
293                 return PTR_ERR(leds_class);
294         leds_class->suspend = led_suspend;
295         leds_class->resume = led_resume;
296         leds_class->dev_attrs = led_class_attrs;
297         return 0;
298 }
299
300 static void __exit leds_exit(void)
301 {
302         class_destroy(leds_class);
303 }
304
305 subsys_initcall(leds_init);
306 module_exit(leds_exit);
307
308 MODULE_AUTHOR("John Lenz, Richard Purdie");
309 MODULE_LICENSE("GPL");
310 MODULE_DESCRIPTION("LED Class Interface");