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	int rc;
95
96	led_cdev->class_dev = class_device_create(leds_class, NULL, 0,
97						parent, "%s", led_cdev->name);
98	if (unlikely(IS_ERR(led_cdev->class_dev)))
99		return PTR_ERR(led_cdev->class_dev);
100
101	class_set_devdata(led_cdev->class_dev, led_cdev);
102
103	/* register the attributes */
104	rc = class_device_create_file(led_cdev->class_dev,
105				      &class_device_attr_brightness);
106	if (rc)
107		goto err_out;
108
109	/* add to the list of leds */
110	write_lock(&leds_list_lock);
111	list_add_tail(&led_cdev->node, &leds_list);
112	write_unlock(&leds_list_lock);
113
114#ifdef CONFIG_LEDS_TRIGGERS
115	rwlock_init(&led_cdev->trigger_lock);
116
117	rc = class_device_create_file(led_cdev->class_dev,
118				      &class_device_attr_trigger);
119	if (rc)
120		goto err_out_led_list;
121
122	led_trigger_set_default(led_cdev);
123#endif
124
125	printk(KERN_INFO "Registered led device: %s\n",
126			led_cdev->class_dev->class_id);
127
128	return 0;
129
130#ifdef CONFIG_LEDS_TRIGGERS
131err_out_led_list:
132	class_device_remove_file(led_cdev->class_dev,
133				&class_device_attr_brightness);
134	list_del(&led_cdev->node);
135#endif
136err_out:
137	class_device_unregister(led_cdev->class_dev);
138	return rc;
139}
140EXPORT_SYMBOL_GPL(led_classdev_register);
141
142/**
143 * led_classdev_unregister - unregisters a object of led_properties class.
144 * @led_cdev: the led device to unregister
145 *
146 * Unregisters a previously registered via led_classdev_register object.
147 */
148void led_classdev_unregister(struct led_classdev *led_cdev)
149{
150	class_device_remove_file(led_cdev->class_dev,
151				&class_device_attr_brightness);
152#ifdef CONFIG_LEDS_TRIGGERS
153	class_device_remove_file(led_cdev->class_dev,
154				&class_device_attr_trigger);
155	write_lock(&led_cdev->trigger_lock);
156	if (led_cdev->trigger)
157		led_trigger_set(led_cdev, NULL);
158	write_unlock(&led_cdev->trigger_lock);
159#endif
160
161	class_device_unregister(led_cdev->class_dev);
162
163	write_lock(&leds_list_lock);
164	list_del(&led_cdev->node);
165	write_unlock(&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");
188