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) 2005-2007 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
25static struct class *leds_class;
26
27static 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
40static 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
60static DEVICE_ATTR(brightness, 0644, led_brightness_show, led_brightness_store);
61#ifdef CONFIG_LEDS_TRIGGERS
62static 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 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
129err_out_led_list:
130 device_remove_file(led_cdev->dev, &dev_attr_brightness);
131 list_del(&led_cdev->node);
132#endif
133err_out:
134 device_unregister(led_cdev->dev);
135 return rc;
136}
137EXPORT_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 * @suspended: indicates whether system-wide suspend or resume is in progress
143 *
144 * Unregisters a previously registered via led_classdev_register object.
145 */
146void __led_classdev_unregister(struct led_classdev *led_cdev,
147 bool suspended)
148{
149 device_remove_file(led_cdev->dev, &dev_attr_brightness);
150#ifdef CONFIG_LEDS_TRIGGERS
151 device_remove_file(led_cdev->dev, &dev_attr_trigger);
152 down_write(&led_cdev->trigger_lock);
153 if (led_cdev->trigger)
154 led_trigger_set(led_cdev, NULL);
155 up_write(&led_cdev->trigger_lock);
156#endif
157
158 if (suspended)
159 device_pm_schedule_removal(led_cdev->dev);
160 else
161 device_unregister(led_cdev->dev);
162
163 down_write(&leds_list_lock);
164 list_del(&led_cdev->node);
165 up_write(&leds_list_lock);
166}
167EXPORT_SYMBOL_GPL(__led_classdev_unregister);
168
169static int __init leds_init(void)
170{
171 leds_class = class_create(THIS_MODULE, "leds");
172 if (IS_ERR(leds_class))
173 return PTR_ERR(leds_class);
174 return 0;
175}
176
177static void __exit leds_exit(void)
178{
179 class_destroy(leds_class);
180}
181
182subsys_initcall(leds_init);
183module_exit(leds_exit);
184
185MODULE_AUTHOR("John Lenz, Richard Purdie");
186MODULE_LICENSE("GPL");
187MODULE_DESCRIPTION("LED Class Interface");