Linux 2.6.34-rc3
[pohmelfs.git] / drivers / leds / led-class.c
blob69e7d86a5143e36d2db68275214e4af539777be4
1 /*
2 * LED Class Core
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
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.
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"
25 static struct class *leds_class;
27 static void led_update_brightness(struct led_classdev *led_cdev)
29 if (led_cdev->brightness_get)
30 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
33 static ssize_t led_brightness_show(struct device *dev,
34 struct device_attribute *attr, char *buf)
36 struct led_classdev *led_cdev = dev_get_drvdata(dev);
38 /* no lock needed for this */
39 led_update_brightness(led_cdev);
41 return sprintf(buf, "%u\n", led_cdev->brightness);
44 static ssize_t led_brightness_store(struct device *dev,
45 struct device_attribute *attr, const char *buf, size_t size)
47 struct led_classdev *led_cdev = dev_get_drvdata(dev);
48 ssize_t ret = -EINVAL;
49 char *after;
50 unsigned long state = simple_strtoul(buf, &after, 10);
51 size_t count = after - buf;
53 if (isspace(*after))
54 count++;
56 if (count == size) {
57 ret = count;
59 if (state == LED_OFF)
60 led_trigger_remove(led_cdev);
61 led_set_brightness(led_cdev, state);
64 return ret;
67 static ssize_t led_max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
75 static struct device_attribute led_class_attrs[] = {
76 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
77 __ATTR(max_brightness, 0644, led_max_brightness_show, NULL),
78 #ifdef CONFIG_LEDS_TRIGGERS
79 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
80 #endif
81 __ATTR_NULL,
84 /**
85 * led_classdev_suspend - suspend an led_classdev.
86 * @led_cdev: the led_classdev to suspend.
88 void led_classdev_suspend(struct led_classdev *led_cdev)
90 led_cdev->flags |= LED_SUSPENDED;
91 led_cdev->brightness_set(led_cdev, 0);
93 EXPORT_SYMBOL_GPL(led_classdev_suspend);
95 /**
96 * led_classdev_resume - resume an led_classdev.
97 * @led_cdev: the led_classdev to resume.
99 void led_classdev_resume(struct led_classdev *led_cdev)
101 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
102 led_cdev->flags &= ~LED_SUSPENDED;
104 EXPORT_SYMBOL_GPL(led_classdev_resume);
106 static int led_suspend(struct device *dev, pm_message_t state)
108 struct led_classdev *led_cdev = dev_get_drvdata(dev);
110 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
111 led_classdev_suspend(led_cdev);
113 return 0;
116 static int led_resume(struct device *dev)
118 struct led_classdev *led_cdev = dev_get_drvdata(dev);
120 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
121 led_classdev_resume(led_cdev);
123 return 0;
127 * led_classdev_register - register a new object of led_classdev class.
128 * @parent: The device to register.
129 * @led_cdev: the led_classdev structure for this device.
131 int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
133 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
134 "%s", led_cdev->name);
135 if (IS_ERR(led_cdev->dev))
136 return PTR_ERR(led_cdev->dev);
138 #ifdef CONFIG_LEDS_TRIGGERS
139 init_rwsem(&led_cdev->trigger_lock);
140 #endif
141 /* add to the list of leds */
142 down_write(&leds_list_lock);
143 list_add_tail(&led_cdev->node, &leds_list);
144 up_write(&leds_list_lock);
146 if (!led_cdev->max_brightness)
147 led_cdev->max_brightness = LED_FULL;
149 led_update_brightness(led_cdev);
151 #ifdef CONFIG_LEDS_TRIGGERS
152 led_trigger_set_default(led_cdev);
153 #endif
155 printk(KERN_DEBUG "Registered led device: %s\n",
156 led_cdev->name);
158 return 0;
161 EXPORT_SYMBOL_GPL(led_classdev_register);
164 * led_classdev_unregister - unregisters a object of led_properties class.
165 * @led_cdev: the led device to unregister
167 * Unregisters a previously registered via led_classdev_register object.
169 void led_classdev_unregister(struct led_classdev *led_cdev)
171 #ifdef CONFIG_LEDS_TRIGGERS
172 down_write(&led_cdev->trigger_lock);
173 if (led_cdev->trigger)
174 led_trigger_set(led_cdev, NULL);
175 up_write(&led_cdev->trigger_lock);
176 #endif
178 device_unregister(led_cdev->dev);
180 down_write(&leds_list_lock);
181 list_del(&led_cdev->node);
182 up_write(&leds_list_lock);
184 EXPORT_SYMBOL_GPL(led_classdev_unregister);
186 static int __init leds_init(void)
188 leds_class = class_create(THIS_MODULE, "leds");
189 if (IS_ERR(leds_class))
190 return PTR_ERR(leds_class);
191 leds_class->suspend = led_suspend;
192 leds_class->resume = led_resume;
193 leds_class->dev_attrs = led_class_attrs;
194 return 0;
197 static void __exit leds_exit(void)
199 class_destroy(leds_class);
202 subsys_initcall(leds_init);
203 module_exit(leds_exit);
205 MODULE_AUTHOR("John Lenz, Richard Purdie");
206 MODULE_LICENSE("GPL");
207 MODULE_DESCRIPTION("LED Class Interface");