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Richard Purdiec72a1d62006-03-31 02:31:04 -08001/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
Richard Purdief8a7c6f2007-07-08 23:19:31 +01005 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
Richard Purdiec72a1d62006-03-31 02:31:04 -08006 *
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
Richard Purdiec72a1d62006-03-31 02:31:04 -080012#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>
Richard Purdiec72a1d62006-03-31 02:31:04 -080018#include <linux/timer.h>
19#include <linux/err.h>
Richard Purdie3dc7b822006-05-15 09:44:17 -070020#include <linux/ctype.h>
Richard Purdiec72a1d62006-03-31 02:31:04 -080021#include <linux/leds.h>
22#include "leds.h"
23
24static struct class *leds_class;
25
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +000026static void led_update_brightness(struct led_classdev *led_cdev)
27{
28 if (led_cdev->brightness_get)
29 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
30}
31
Jeffrin Jose9cd5ec52012-06-03 20:11:52 +080032static ssize_t led_brightness_show(struct device *dev,
Richard Purdief8a7c6f2007-07-08 23:19:31 +010033 struct device_attribute *attr, char *buf)
Richard Purdiec72a1d62006-03-31 02:31:04 -080034{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010035 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080036
37 /* no lock needed for this */
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +000038 led_update_brightness(led_cdev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080039
Sven Wegenerdd8e5a22008-10-13 10:41:39 +010040 return sprintf(buf, "%u\n", led_cdev->brightness);
Richard Purdiec72a1d62006-03-31 02:31:04 -080041}
42
Richard Purdief8a7c6f2007-07-08 23:19:31 +010043static ssize_t led_brightness_store(struct device *dev,
44 struct device_attribute *attr, const char *buf, size_t size)
Richard Purdiec72a1d62006-03-31 02:31:04 -080045{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010046 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Shuah Khan872b86b2012-05-29 15:07:26 -070047 unsigned long state;
Richard Purdiec72a1d62006-03-31 02:31:04 -080048 ssize_t ret = -EINVAL;
Richard Purdiec72a1d62006-03-31 02:31:04 -080049
Shuah Khan872b86b2012-05-29 15:07:26 -070050 ret = kstrtoul(buf, 10, &state);
51 if (ret)
52 return ret;
Richard Purdie3dc7b822006-05-15 09:44:17 -070053
Shuah Khan872b86b2012-05-29 15:07:26 -070054 if (state == LED_OFF)
55 led_trigger_remove(led_cdev);
Shuah Khan0da3e652012-06-13 10:01:37 +080056 __led_set_brightness(led_cdev, state);
Németh Márton0013b232008-03-09 20:54:37 +000057
Shuah Khan872b86b2012-05-29 15:07:26 -070058 return size;
Richard Purdiec72a1d62006-03-31 02:31:04 -080059}
60
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +000061static ssize_t led_max_brightness_show(struct device *dev,
62 struct device_attribute *attr, char *buf)
63{
64 struct led_classdev *led_cdev = dev_get_drvdata(dev);
65
66 return sprintf(buf, "%u\n", led_cdev->max_brightness);
67}
68
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010069static struct device_attribute led_class_attrs[] = {
70 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
Axel Lin569762e2010-05-17 08:48:28 +080071 __ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
Richard Purdiec3bc9952006-03-31 02:31:05 -080072#ifdef CONFIG_LEDS_TRIGGERS
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010073 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
Richard Purdiec3bc9952006-03-31 02:31:05 -080074#endif
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010075 __ATTR_NULL,
76};
Richard Purdiec72a1d62006-03-31 02:31:04 -080077
Johannes Berg5ada28b2010-11-11 14:05:21 -080078static void led_timer_function(unsigned long data)
79{
80 struct led_classdev *led_cdev = (void *)data;
81 unsigned long brightness;
82 unsigned long delay;
83
84 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
Shuah Khan0da3e652012-06-13 10:01:37 +080085 __led_set_brightness(led_cdev, LED_OFF);
Johannes Berg5ada28b2010-11-11 14:05:21 -080086 return;
87 }
88
Fabio Baltieri5bb629c2012-05-27 07:19:22 +080089 if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
90 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
91 return;
92 }
93
Johannes Berg5ada28b2010-11-11 14:05:21 -080094 brightness = led_get_brightness(led_cdev);
95 if (!brightness) {
96 /* Time to switch the LED on. */
97 brightness = led_cdev->blink_brightness;
98 delay = led_cdev->blink_delay_on;
99 } else {
100 /* Store the current brightness value to be able
101 * to restore it when the delay_off period is over.
102 */
103 led_cdev->blink_brightness = brightness;
104 brightness = LED_OFF;
105 delay = led_cdev->blink_delay_off;
106 }
107
Shuah Khan0da3e652012-06-13 10:01:37 +0800108 __led_set_brightness(led_cdev, brightness);
Johannes Berg5ada28b2010-11-11 14:05:21 -0800109
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800110 /* Return in next iteration if led is in one-shot mode and we are in
111 * the final blink state so that the led is toggled each delay_on +
112 * delay_off milliseconds in worst case.
113 */
114 if (led_cdev->flags & LED_BLINK_ONESHOT) {
115 if (led_cdev->flags & LED_BLINK_INVERT) {
116 if (brightness)
117 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
118 } else {
119 if (!brightness)
120 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
121 }
122 }
123
Johannes Berg5ada28b2010-11-11 14:05:21 -0800124 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
125}
126
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800127static void set_brightness_delayed(struct work_struct *ws)
128{
129 struct led_classdev *led_cdev =
130 container_of(ws, struct led_classdev, set_brightness_work);
131
132 led_stop_software_blink(led_cdev);
133
134 __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
135}
136
Richard Purdiec72a1d62006-03-31 02:31:04 -0800137/**
138 * led_classdev_suspend - suspend an led_classdev.
139 * @led_cdev: the led_classdev to suspend.
140 */
141void led_classdev_suspend(struct led_classdev *led_cdev)
142{
143 led_cdev->flags |= LED_SUSPENDED;
144 led_cdev->brightness_set(led_cdev, 0);
145}
146EXPORT_SYMBOL_GPL(led_classdev_suspend);
147
148/**
149 * led_classdev_resume - resume an led_classdev.
150 * @led_cdev: the led_classdev to resume.
151 */
152void led_classdev_resume(struct led_classdev *led_cdev)
153{
154 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
155 led_cdev->flags &= ~LED_SUSPENDED;
156}
157EXPORT_SYMBOL_GPL(led_classdev_resume);
158
Richard Purdie859cb7f2009-01-08 17:55:03 +0000159static int led_suspend(struct device *dev, pm_message_t state)
160{
161 struct led_classdev *led_cdev = dev_get_drvdata(dev);
162
163 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
164 led_classdev_suspend(led_cdev);
165
166 return 0;
167}
168
169static int led_resume(struct device *dev)
170{
171 struct led_classdev *led_cdev = dev_get_drvdata(dev);
172
173 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
174 led_classdev_resume(led_cdev);
175
176 return 0;
177}
178
Richard Purdiec72a1d62006-03-31 02:31:04 -0800179/**
180 * led_classdev_register - register a new object of led_classdev class.
Sven Wegenerff8649a2008-12-03 08:04:57 +0000181 * @parent: The device to register.
Richard Purdiec72a1d62006-03-31 02:31:04 -0800182 * @led_cdev: the led_classdev structure for this device.
183 */
184int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
185{
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700186 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
187 "%s", led_cdev->name);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700188 if (IS_ERR(led_cdev->dev))
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100189 return PTR_ERR(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800190
Richard Purdie270c3952008-10-20 23:16:17 +0100191#ifdef CONFIG_LEDS_TRIGGERS
192 init_rwsem(&led_cdev->trigger_lock);
193#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800194 /* add to the list of leds */
Richard Purdie72f8da32007-12-31 23:09:44 +0000195 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800196 list_add_tail(&led_cdev->node, &leds_list);
Richard Purdie72f8da32007-12-31 23:09:44 +0000197 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800198
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +0000199 if (!led_cdev->max_brightness)
200 led_cdev->max_brightness = LED_FULL;
201
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +0000202 led_update_brightness(led_cdev);
203
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800204 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
205
Johannes Berg5ada28b2010-11-11 14:05:21 -0800206 init_timer(&led_cdev->blink_timer);
207 led_cdev->blink_timer.function = led_timer_function;
208 led_cdev->blink_timer.data = (unsigned long)led_cdev;
209
Richard Purdiec3bc9952006-03-31 02:31:05 -0800210#ifdef CONFIG_LEDS_TRIGGERS
Jeff Garzik12fda162006-10-17 00:10:20 -0700211 led_trigger_set_default(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800212#endif
213
H Hartley Sweetenbb9b6ef2010-01-06 15:34:55 -0700214 printk(KERN_DEBUG "Registered led device: %s\n",
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100215 led_cdev->name);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800216
217 return 0;
218}
219EXPORT_SYMBOL_GPL(led_classdev_register);
220
221/**
Qinghuang Feng0266a452008-10-20 23:04:36 +0100222 * led_classdev_unregister - unregisters a object of led_properties class.
Henrik Kretzschmar70d63cc2006-10-03 23:31:30 +0200223 * @led_cdev: the led device to unregister
Richard Purdiec72a1d62006-03-31 02:31:04 -0800224 *
225 * Unregisters a previously registered via led_classdev_register object.
226 */
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100227void led_classdev_unregister(struct led_classdev *led_cdev)
Richard Purdiec72a1d62006-03-31 02:31:04 -0800228{
Richard Purdiec3bc9952006-03-31 02:31:05 -0800229#ifdef CONFIG_LEDS_TRIGGERS
Richard Purdiedc472062007-11-10 13:29:04 +0000230 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800231 if (led_cdev->trigger)
232 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000233 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800234#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800235
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800236 cancel_work_sync(&led_cdev->set_brightness_work);
237
Johannes Berg5ada28b2010-11-11 14:05:21 -0800238 /* Stop blinking */
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800239 led_stop_software_blink(led_cdev);
Shuah Khan19cd67e2012-06-14 04:34:30 +0800240 led_set_brightness(led_cdev, LED_OFF);
Johannes Berg5ada28b2010-11-11 14:05:21 -0800241
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100242 device_unregister(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800243
Richard Purdie72f8da32007-12-31 23:09:44 +0000244 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800245 list_del(&led_cdev->node);
Richard Purdie72f8da32007-12-31 23:09:44 +0000246 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800247}
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100248EXPORT_SYMBOL_GPL(led_classdev_unregister);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800249
250static int __init leds_init(void)
251{
252 leds_class = class_create(THIS_MODULE, "leds");
253 if (IS_ERR(leds_class))
254 return PTR_ERR(leds_class);
Richard Purdie859cb7f2009-01-08 17:55:03 +0000255 leds_class->suspend = led_suspend;
256 leds_class->resume = led_resume;
Florian Fainelli14b5d6d2010-03-10 18:32:18 +0100257 leds_class->dev_attrs = led_class_attrs;
Richard Purdiec72a1d62006-03-31 02:31:04 -0800258 return 0;
259}
260
261static void __exit leds_exit(void)
262{
263 class_destroy(leds_class);
264}
265
266subsys_initcall(leds_init);
267module_exit(leds_exit);
268
269MODULE_AUTHOR("John Lenz, Richard Purdie");
270MODULE_LICENSE("GPL");
271MODULE_DESCRIPTION("LED Class Interface");