1 /*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2006 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/config.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/list.h>
17 #include <linux/spinlock.h>
18 #include <linux/device.h>
19 #include <linux/sysdev.h>
20 #include <linux/timer.h>
21 #include <linux/err.h>
22 #include <linux/ctype.h>
23 #include <linux/leds.h>
24 #include "leds.h"
25
26 static struct class *leds_class;
27
28 static ssize_t led_brightness_show(struct class_device *dev, char *buf)
29 {
30 struct led_classdev *led_cdev = class_get_devdata(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 class_device *dev,
41 const char *buf, size_t size)
42 {
43 struct led_classdev *led_cdev = class_get_devdata(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 CLASS_DEVICE_ATTR(brightness, 0644, led_brightness_show,
61 led_brightness_store);
62 #ifdef CONFIG_LEDS_TRIGGERS
63 static CLASS_DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
64 #endif
65
66 /**
67 * led_classdev_suspend - suspend an led_classdev.
68 * @led_cdev: the led_classdev to suspend.
69 */
70 void led_classdev_suspend(struct led_classdev *led_cdev)
71 {
72 led_cdev->flags |= LED_SUSPENDED;
73 led_cdev->brightness_set(led_cdev, 0);
74 }
75 EXPORT_SYMBOL_GPL(led_classdev_suspend);
76
77 /**
78 * led_classdev_resume - resume an led_classdev.
79 * @led_cdev: the led_classdev to resume.
80 */
81 void led_classdev_resume(struct led_classdev *led_cdev)
82 {
83 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
84 led_cdev->flags &= ~LED_SUSPENDED;
85 }
86 EXPORT_SYMBOL_GPL(led_classdev_resume);
87
88 /**
89 * led_classdev_register - register a new object of led_classdev class.
90 * @dev: The device to register.
91 * @led_cdev: the led_classdev structure for this device.
92 */
93 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
94 {
95 led_cdev->class_dev = class_device_create(leds_class, NULL, 0,
96 parent, "%s", led_cdev->name);
97 if (unlikely(IS_ERR(led_cdev->class_dev)))
98 return PTR_ERR(led_cdev->class_dev);
99
100 class_set_devdata(led_cdev->class_dev, led_cdev);
101
102 /* register the attributes */
103 class_device_create_file(led_cdev->class_dev,
104 &class_device_attr_brightness);
105
106 /* add to the list of leds */
107 write_lock(&leds_list_lock);
108 list_add_tail(&led_cdev->node, &leds_list);
109 write_unlock(&leds_list_lock);
110
111 #ifdef CONFIG_LEDS_TRIGGERS
112 rwlock_init(&led_cdev->trigger_lock);
113
114 led_trigger_set_default(led_cdev);
115
116 class_device_create_file(led_cdev->class_dev,
117 &class_device_attr_trigger);
118 #endif
119
120 printk(KERN_INFO "Registered led device: %s\n",
121 led_cdev->class_dev->class_id);
122
123 return 0;
124 }
125 EXPORT_SYMBOL_GPL(led_classdev_register);
126
127 /**
128 * led_classdev_unregister - unregisters a object of led_properties class.
129 * @led_cdev: the led device to unreigister
130 *
131 * Unregisters a previously registered via led_classdev_register object.
132 */
133 void led_classdev_unregister(struct led_classdev *led_cdev)
134 {
135 class_device_remove_file(led_cdev->class_dev,
136 &class_device_attr_brightness);
137 #ifdef CONFIG_LEDS_TRIGGERS
138 class_device_remove_file(led_cdev->class_dev,
139 &class_device_attr_trigger);
140 write_lock(&led_cdev->trigger_lock);
141 if (led_cdev->trigger)
142 led_trigger_set(led_cdev, NULL);
143 write_unlock(&led_cdev->trigger_lock);
144 #endif
145
146 class_device_unregister(led_cdev->class_dev);
147
148 write_lock(&leds_list_lock);
149 list_del(&led_cdev->node);
150 write_unlock(&leds_list_lock);
151 }
152 EXPORT_SYMBOL_GPL(led_classdev_unregister);
153
154 static int __init leds_init(void)
155 {
156 leds_class = class_create(THIS_MODULE, "leds");
157 if (IS_ERR(leds_class))
158 return PTR_ERR(leds_class);
159 return 0;
160 }
161
162 static void __exit leds_exit(void)
163 {
164 class_destroy(leds_class);
165 }
166
167 subsys_initcall(leds_init);
168 module_exit(leds_exit);
169
170 MODULE_AUTHOR("John Lenz, Richard Purdie");
171 MODULE_LICENSE("GPL");
172 MODULE_DESCRIPTION("LED Class Interface");
173
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