tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/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
25static struct class *leds_class;
26
27static ssize_t led_brightness_show(struct class_device *dev, char *buf)
28{
29 struct led_classdev *led_cdev = class_get_devdata(dev);
30 ssize_t ret = 0;
31
32 /* no lock needed for this */
33 sprintf(buf, "%u\n", led_cdev->brightness);
34 ret = strlen(buf) + 1;
35
36 return ret;
37}
38
39static ssize_t led_brightness_store(struct class_device *dev,
40 const char *buf, size_t size)
41{
42 struct led_classdev *led_cdev = class_get_devdata(dev);
43 ssize_t ret = -EINVAL;
44 char *after;
45 unsigned long state = simple_strtoul(buf, &after, 10);
46 size_t count = after - buf;
47
48 if (*after && isspace(*after))
49 count++;
50
51 if (count == size) {
52 ret = count;
53 led_set_brightness(led_cdev, state);
54 }
55
56 return ret;
57}
58
59static CLASS_DEVICE_ATTR(brightness, 0644, led_brightness_show,
60 led_brightness_store);
61#ifdef CONFIG_LEDS_TRIGGERS
62static CLASS_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 */
69void led_classdev_suspend(struct led_classdev *led_cdev)
70{
71 led_cdev->flags |= LED_SUSPENDED;
72 led_cdev->brightness_set(led_cdev, 0);
73}
74EXPORT_SYMBOL_GPL(led_classdev_suspend);
75
76/**
77 * led_classdev_resume - resume an led_classdev.
78 * @led_cdev: the led_classdev to resume.
79 */
80void 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}
85EXPORT_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 */
92int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
93{
94 led_cdev->class_dev = class_device_create(leds_class, NULL, 0,
95 parent, "%s", led_cdev->name);
96 if (unlikely(IS_ERR(led_cdev->class_dev)))
97 return PTR_ERR(led_cdev->class_dev);
98
99 class_set_devdata(led_cdev->class_dev, led_cdev);
100
101 /* register the attributes */
102 class_device_create_file(led_cdev->class_dev,
103 &class_device_attr_brightness);
104
105 /* add to the list of leds */
106 write_lock(&leds_list_lock);
107 list_add_tail(&led_cdev->node, &leds_list);
108 write_unlock(&leds_list_lock);
109
110#ifdef CONFIG_LEDS_TRIGGERS
111 rwlock_init(&led_cdev->trigger_lock);
112
113 led_trigger_set_default(led_cdev);
114
115 class_device_create_file(led_cdev->class_dev,
116 &class_device_attr_trigger);
117#endif
118
119 printk(KERN_INFO "Registered led device: %s\n",
120 led_cdev->class_dev->class_id);
121
122 return 0;
123}
124EXPORT_SYMBOL_GPL(led_classdev_register);
125
126/**
127 * led_classdev_unregister - unregisters a object of led_properties class.
128 * @led_cdev: the led device to unregister
129 *
130 * Unregisters a previously registered via led_classdev_register object.
131 */
132void led_classdev_unregister(struct led_classdev *led_cdev)
133{
134 class_device_remove_file(led_cdev->class_dev,
135 &class_device_attr_brightness);
136#ifdef CONFIG_LEDS_TRIGGERS
137 class_device_remove_file(led_cdev->class_dev,
138 &class_device_attr_trigger);
139 write_lock(&led_cdev->trigger_lock);
140 if (led_cdev->trigger)
141 led_trigger_set(led_cdev, NULL);
142 write_unlock(&led_cdev->trigger_lock);
143#endif
144
145 class_device_unregister(led_cdev->class_dev);
146
147 write_lock(&leds_list_lock);
148 list_del(&led_cdev->node);
149 write_unlock(&leds_list_lock);
150}
151EXPORT_SYMBOL_GPL(led_classdev_unregister);
152
153static int __init leds_init(void)
154{
155 leds_class = class_create(THIS_MODULE, "leds");
156 if (IS_ERR(leds_class))
157 return PTR_ERR(leds_class);
158 return 0;
159}
160
161static void __exit leds_exit(void)
162{
163 class_destroy(leds_class);
164}
165
166subsys_initcall(leds_init);
167module_exit(leds_exit);
168
169MODULE_AUTHOR("John Lenz, Richard Purdie");
170MODULE_LICENSE("GPL");
171MODULE_DESCRIPTION("LED Class Interface");