1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/*
* LED Class Core
*
* Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
* Copyright (C) 2005-2006 Richard Purdie <rpurdie@openedhand.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <linux/err.h>
#include <linux/leds.h>
#include "leds.h"
static struct class *leds_class;
static ssize_t led_brightness_show(struct class_device *dev, char *buf)
{
struct led_classdev *led_cdev = class_get_devdata(dev);
ssize_t ret = 0;
/* no lock needed for this */
sprintf(buf, "%u\n", led_cdev->brightness);
ret = strlen(buf) + 1;
return ret;
}
static ssize_t led_brightness_store(struct class_device *dev,
const char *buf, size_t size)
{
struct led_classdev *led_cdev = class_get_devdata(dev);
ssize_t ret = -EINVAL;
char *after;
unsigned long state = simple_strtoul(buf, &after, 10);
if (after - buf > 0) {
ret = after - buf;
led_set_brightness(led_cdev, state);
}
return ret;
}
static CLASS_DEVICE_ATTR(brightness, 0644, led_brightness_show,
led_brightness_store);
#ifdef CONFIG_LEDS_TRIGGERS
static CLASS_DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
#endif
/**
* led_classdev_suspend - suspend an led_classdev.
* @led_cdev: the led_classdev to suspend.
*/
void led_classdev_suspend(struct led_classdev *led_cdev)
{
led_cdev->flags |= LED_SUSPENDED;
led_cdev->brightness_set(led_cdev, 0);
}
EXPORT_SYMBOL_GPL(led_classdev_suspend);
/**
* led_classdev_resume - resume an led_classdev.
* @led_cdev: the led_classdev to resume.
*/
void led_classdev_resume(struct led_classdev *led_cdev)
{
led_cdev->brightness_set(led_cdev, led_cdev->brightness);
led_cdev->flags &= ~LED_SUSPENDED;
}
EXPORT_SYMBOL_GPL(led_classdev_resume);
/**
* led_classdev_register - register a new object of led_classdev class.
* @dev: The device to register.
* @led_cdev: the led_classdev structure for this device.
*/
int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
{
led_cdev->class_dev = class_device_create(leds_class, NULL, 0,
parent, "%s", led_cdev->name);
if (unlikely(IS_ERR(led_cdev->class_dev)))
return PTR_ERR(led_cdev->class_dev);
class_set_devdata(led_cdev->class_dev, led_cdev);
/* register the attributes */
class_device_create_file(led_cdev->class_dev,
&class_device_attr_brightness);
/* add to the list of leds */
write_lock(&leds_list_lock);
list_add_tail(&led_cdev->node, &leds_list);
write_unlock(&leds_list_lock);
#ifdef CONFIG_LEDS_TRIGGERS
rwlock_init(&led_cdev->trigger_lock);
led_trigger_set_default(led_cdev);
class_device_create_file(led_cdev->class_dev,
&class_device_attr_trigger);
#endif
printk(KERN_INFO "Registered led device: %s\n",
led_cdev->class_dev->class_id);
return 0;
}
EXPORT_SYMBOL_GPL(led_classdev_register);
/**
* led_classdev_unregister - unregisters a object of led_properties class.
* @led_cdev: the led device to unreigister
*
* Unregisters a previously registered via led_classdev_register object.
*/
void led_classdev_unregister(struct led_classdev *led_cdev)
{
class_device_remove_file(led_cdev->class_dev,
&class_device_attr_brightness);
#ifdef CONFIG_LEDS_TRIGGERS
class_device_remove_file(led_cdev->class_dev,
&class_device_attr_trigger);
write_lock(&led_cdev->trigger_lock);
if (led_cdev->trigger)
led_trigger_set(led_cdev, NULL);
write_unlock(&led_cdev->trigger_lock);
#endif
class_device_unregister(led_cdev->class_dev);
write_lock(&leds_list_lock);
list_del(&led_cdev->node);
write_unlock(&leds_list_lock);
}
EXPORT_SYMBOL_GPL(led_classdev_unregister);
static int __init leds_init(void)
{
leds_class = class_create(THIS_MODULE, "leds");
if (IS_ERR(leds_class))
return PTR_ERR(leds_class);
return 0;
}
static void __exit leds_exit(void)
{
class_destroy(leds_class);
}
subsys_initcall(leds_init);
module_exit(leds_exit);
MODULE_AUTHOR("John Lenz, Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Class Interface");
|
