Merge git://git.infradead.org/~dedekind/ubi-2.6
[linux-2.6] / 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 ssize_t led_brightness_show(struct device *dev, 
28                 struct device_attribute *attr, char *buf)
29 {
30         struct led_classdev *led_cdev = dev_get_drvdata(dev);
31         ssize_t ret = 0;
32
33         /* no lock needed for this */
34         sprintf(buf, "%u\n", led_cdev->brightness);
35         ret = strlen(buf) + 1;
36
37         return ret;
38 }
39
40 static ssize_t led_brightness_store(struct device *dev,
41                 struct device_attribute *attr, const char *buf, size_t size)
42 {
43         struct led_classdev *led_cdev = dev_get_drvdata(dev);
44         ssize_t ret = -EINVAL;
45         char *after;
46         unsigned long state = simple_strtoul(buf, &after, 10);
47         size_t count = after - buf;
48
49         if (*after && isspace(*after))
50                 count++;
51
52         if (count == size) {
53                 ret = count;
54                 led_set_brightness(led_cdev, state);
55         }
56
57         return ret;
58 }
59
60 static DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store);
61 #ifdef CONFIG_LEDS_TRIGGERS
62 static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
63 #endif
64
65 /**
66  * led_classdev_suspend - suspend an led_classdev.
67  * @led_cdev: the led_classdev to suspend.
68  */
69 void led_classdev_suspend(struct led_classdev *led_cdev)
70 {
71         led_cdev->flags |= LED_SUSPENDED;
72         led_cdev->brightness_set(led_cdev, 0);
73 }
74 EXPORT_SYMBOL_GPL(led_classdev_suspend);
75
76 /**
77  * led_classdev_resume - resume an led_classdev.
78  * @led_cdev: the led_classdev to resume.
79  */
80 void led_classdev_resume(struct led_classdev *led_cdev)
81 {
82         led_cdev->brightness_set(led_cdev, led_cdev->brightness);
83         led_cdev->flags &= ~LED_SUSPENDED;
84 }
85 EXPORT_SYMBOL_GPL(led_classdev_resume);
86
87 /**
88  * led_classdev_register - register a new object of led_classdev class.
89  * @dev: The device to register.
90  * @led_cdev: the led_classdev structure for this device.
91  */
92 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
93 {
94         int rc;
95
96         led_cdev->dev = device_create(leds_class, parent, 0, "%s",
97                                             led_cdev->name);
98         if (unlikely(IS_ERR(led_cdev->dev)))
99                 return PTR_ERR(led_cdev->dev);
100
101         dev_set_drvdata(led_cdev->dev, led_cdev);
102
103         /* register the attributes */
104         rc = device_create_file(led_cdev->dev, &dev_attr_brightness);
105         if (rc)
106                 goto err_out;
107
108         /* add to the list of leds */
109         down_write(&leds_list_lock);
110         list_add_tail(&led_cdev->node, &leds_list);
111         up_write(&leds_list_lock);
112
113 #ifdef CONFIG_LEDS_TRIGGERS
114         init_rwsem(&led_cdev->trigger_lock);
115
116         rc = device_create_file(led_cdev->dev, &dev_attr_trigger);
117         if (rc)
118                 goto err_out_led_list;
119
120         led_trigger_set_default(led_cdev);
121 #endif
122
123         printk(KERN_INFO "Registered led device: %s\n",
124                         led_cdev->name);
125
126         return 0;
127
128 #ifdef CONFIG_LEDS_TRIGGERS
129 err_out_led_list:
130         device_remove_file(led_cdev->dev, &dev_attr_brightness);
131         list_del(&led_cdev->node);
132 #endif
133 err_out:
134         device_unregister(led_cdev->dev);
135         return rc;
136 }
137 EXPORT_SYMBOL_GPL(led_classdev_register);
138
139 /**
140  * __led_classdev_unregister - unregisters a object of led_properties class.
141  * @led_cdev: the led device to unregister
142  *
143  * Unregisters a previously registered via led_classdev_register object.
144  */
145 void led_classdev_unregister(struct led_classdev *led_cdev)
146 {
147         device_remove_file(led_cdev->dev, &dev_attr_brightness);
148 #ifdef CONFIG_LEDS_TRIGGERS
149         device_remove_file(led_cdev->dev, &dev_attr_trigger);
150         down_write(&led_cdev->trigger_lock);
151         if (led_cdev->trigger)
152                 led_trigger_set(led_cdev, NULL);
153         up_write(&led_cdev->trigger_lock);
154 #endif
155
156         device_unregister(led_cdev->dev);
157
158         down_write(&leds_list_lock);
159         list_del(&led_cdev->node);
160         up_write(&leds_list_lock);
161 }
162 EXPORT_SYMBOL_GPL(led_classdev_unregister);
163
164 static int __init leds_init(void)
165 {
166         leds_class = class_create(THIS_MODULE, "leds");
167         if (IS_ERR(leds_class))
168                 return PTR_ERR(leds_class);
169         return 0;
170 }
171
172 static void __exit leds_exit(void)
173 {
174         class_destroy(leds_class);
175 }
176
177 subsys_initcall(leds_init);
178 module_exit(leds_exit);
179
180 MODULE_AUTHOR("John Lenz, Richard Purdie");
181 MODULE_LICENSE("GPL");
182 MODULE_DESCRIPTION("LED Class Interface");