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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>
Jiri Kosina90673592014-09-02 02:03:12 -070018#include <linux/timer.h>
Richard Purdiec72a1d62006-03-31 02:31:04 -080019#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
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070032static ssize_t 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
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070043static ssize_t brightness_store(struct device *dev,
Richard Purdief8a7c6f2007-07-08 23:19:31 +010044 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}
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070060static DEVICE_ATTR_RW(brightness);
Richard Purdiec72a1d62006-03-31 02:31:04 -080061
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +000062static ssize_t led_max_brightness_show(struct device *dev,
63 struct device_attribute *attr, char *buf)
64{
65 struct led_classdev *led_cdev = dev_get_drvdata(dev);
66
67 return sprintf(buf, "%u\n", led_cdev->max_brightness);
68}
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070069static DEVICE_ATTR(max_brightness, 0444, led_max_brightness_show, NULL);
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +000070
Richard Purdiec3bc9952006-03-31 02:31:05 -080071#ifdef CONFIG_LEDS_TRIGGERS
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070072static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
73static struct attribute *led_trigger_attrs[] = {
74 &dev_attr_trigger.attr,
75 NULL,
76};
77static const struct attribute_group led_trigger_group = {
78 .attrs = led_trigger_attrs,
79};
Richard Purdiec3bc9952006-03-31 02:31:05 -080080#endif
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -070081
82static struct attribute *led_class_attrs[] = {
83 &dev_attr_brightness.attr,
84 &dev_attr_max_brightness.attr,
85 NULL,
86};
87
88static const struct attribute_group led_group = {
89 .attrs = led_class_attrs,
90};
91
92static const struct attribute_group *led_groups[] = {
93 &led_group,
94#ifdef CONFIG_LEDS_TRIGGERS
95 &led_trigger_group,
96#endif
97 NULL,
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010098};
Richard Purdiec72a1d62006-03-31 02:31:04 -080099
Jiri Kosina90673592014-09-02 02:03:12 -0700100static void led_timer_function(unsigned long data)
Johannes Berg5ada28b2010-11-11 14:05:21 -0800101{
Jiri Kosina90673592014-09-02 02:03:12 -0700102 struct led_classdev *led_cdev = (void *)data;
Johannes Berg5ada28b2010-11-11 14:05:21 -0800103 unsigned long brightness;
104 unsigned long delay;
105
106 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
Shuah Khan0da3e652012-06-13 10:01:37 +0800107 __led_set_brightness(led_cdev, LED_OFF);
Johannes Berg5ada28b2010-11-11 14:05:21 -0800108 return;
109 }
110
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800111 if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
112 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
113 return;
114 }
115
Johannes Berg5ada28b2010-11-11 14:05:21 -0800116 brightness = led_get_brightness(led_cdev);
117 if (!brightness) {
118 /* Time to switch the LED on. */
119 brightness = led_cdev->blink_brightness;
120 delay = led_cdev->blink_delay_on;
121 } else {
122 /* Store the current brightness value to be able
123 * to restore it when the delay_off period is over.
124 */
125 led_cdev->blink_brightness = brightness;
126 brightness = LED_OFF;
127 delay = led_cdev->blink_delay_off;
128 }
129
Shuah Khan0da3e652012-06-13 10:01:37 +0800130 __led_set_brightness(led_cdev, brightness);
Johannes Berg5ada28b2010-11-11 14:05:21 -0800131
Fabio Baltieri5bb629c2012-05-27 07:19:22 +0800132 /* Return in next iteration if led is in one-shot mode and we are in
133 * the final blink state so that the led is toggled each delay_on +
134 * delay_off milliseconds in worst case.
135 */
136 if (led_cdev->flags & LED_BLINK_ONESHOT) {
137 if (led_cdev->flags & LED_BLINK_INVERT) {
138 if (brightness)
139 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
140 } else {
141 if (!brightness)
142 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
143 }
144 }
145
Jiri Kosina90673592014-09-02 02:03:12 -0700146 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
Johannes Berg5ada28b2010-11-11 14:05:21 -0800147}
148
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800149static void set_brightness_delayed(struct work_struct *ws)
150{
151 struct led_classdev *led_cdev =
152 container_of(ws, struct led_classdev, set_brightness_work);
153
154 led_stop_software_blink(led_cdev);
155
156 __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
157}
158
Richard Purdiec72a1d62006-03-31 02:31:04 -0800159/**
160 * led_classdev_suspend - suspend an led_classdev.
161 * @led_cdev: the led_classdev to suspend.
162 */
163void led_classdev_suspend(struct led_classdev *led_cdev)
164{
165 led_cdev->flags |= LED_SUSPENDED;
166 led_cdev->brightness_set(led_cdev, 0);
167}
168EXPORT_SYMBOL_GPL(led_classdev_suspend);
169
170/**
171 * led_classdev_resume - resume an led_classdev.
172 * @led_cdev: the led_classdev to resume.
173 */
174void led_classdev_resume(struct led_classdev *led_cdev)
175{
176 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
177 led_cdev->flags &= ~LED_SUSPENDED;
178}
179EXPORT_SYMBOL_GPL(led_classdev_resume);
180
Shuah Khan73e1ab42013-06-20 12:08:44 -0700181static int led_suspend(struct device *dev)
Richard Purdie859cb7f2009-01-08 17:55:03 +0000182{
183 struct led_classdev *led_cdev = dev_get_drvdata(dev);
184
185 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
186 led_classdev_suspend(led_cdev);
187
188 return 0;
189}
190
191static int led_resume(struct device *dev)
192{
193 struct led_classdev *led_cdev = dev_get_drvdata(dev);
194
195 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
196 led_classdev_resume(led_cdev);
197
198 return 0;
199}
200
Shuah Khan73e1ab42013-06-20 12:08:44 -0700201static const struct dev_pm_ops leds_class_dev_pm_ops = {
202 .suspend = led_suspend,
203 .resume = led_resume,
204};
205
Richard Purdiec72a1d62006-03-31 02:31:04 -0800206/**
207 * led_classdev_register - register a new object of led_classdev class.
Sven Wegenerff8649a2008-12-03 08:04:57 +0000208 * @parent: The device to register.
Richard Purdiec72a1d62006-03-31 02:31:04 -0800209 * @led_cdev: the led_classdev structure for this device.
210 */
211int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
212{
Johan Hovoldd0d480c2014-06-25 10:08:44 -0700213 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
214 led_cdev, led_cdev->groups,
215 "%s", led_cdev->name);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700216 if (IS_ERR(led_cdev->dev))
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100217 return PTR_ERR(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800218
Richard Purdie270c3952008-10-20 23:16:17 +0100219#ifdef CONFIG_LEDS_TRIGGERS
220 init_rwsem(&led_cdev->trigger_lock);
221#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800222 /* add to the list of leds */
Richard Purdie72f8da32007-12-31 23:09:44 +0000223 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800224 list_add_tail(&led_cdev->node, &leds_list);
Richard Purdie72f8da32007-12-31 23:09:44 +0000225 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800226
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +0000227 if (!led_cdev->max_brightness)
228 led_cdev->max_brightness = LED_FULL;
229
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +0000230 led_update_brightness(led_cdev);
231
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800232 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
233
Jiri Kosina90673592014-09-02 02:03:12 -0700234 init_timer(&led_cdev->blink_timer);
235 led_cdev->blink_timer.function = led_timer_function;
236 led_cdev->blink_timer.data = (unsigned long)led_cdev;
Johannes Berg5ada28b2010-11-11 14:05:21 -0800237
Richard Purdiec3bc9952006-03-31 02:31:05 -0800238#ifdef CONFIG_LEDS_TRIGGERS
Jeff Garzik12fda162006-10-17 00:10:20 -0700239 led_trigger_set_default(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800240#endif
241
Sachin Kamatd23e7b82012-11-25 10:57:35 +0530242 dev_dbg(parent, "Registered led device: %s\n",
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100243 led_cdev->name);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800244
245 return 0;
246}
247EXPORT_SYMBOL_GPL(led_classdev_register);
248
249/**
Qinghuang Feng0266a452008-10-20 23:04:36 +0100250 * led_classdev_unregister - unregisters a object of led_properties class.
Henrik Kretzschmar70d63cc2006-10-03 23:31:30 +0200251 * @led_cdev: the led device to unregister
Richard Purdiec72a1d62006-03-31 02:31:04 -0800252 *
253 * Unregisters a previously registered via led_classdev_register object.
254 */
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100255void led_classdev_unregister(struct led_classdev *led_cdev)
Richard Purdiec72a1d62006-03-31 02:31:04 -0800256{
Richard Purdiec3bc9952006-03-31 02:31:05 -0800257#ifdef CONFIG_LEDS_TRIGGERS
Richard Purdiedc472062007-11-10 13:29:04 +0000258 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800259 if (led_cdev->trigger)
260 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000261 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800262#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800263
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800264 cancel_work_sync(&led_cdev->set_brightness_work);
265
Johannes Berg5ada28b2010-11-11 14:05:21 -0800266 /* Stop blinking */
Fabio Baltierid23a22a2012-08-15 21:44:34 +0800267 led_stop_software_blink(led_cdev);
Shuah Khan19cd67e2012-06-14 04:34:30 +0800268 led_set_brightness(led_cdev, LED_OFF);
Johannes Berg5ada28b2010-11-11 14:05:21 -0800269
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100270 device_unregister(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800271
Richard Purdie72f8da32007-12-31 23:09:44 +0000272 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800273 list_del(&led_cdev->node);
Richard Purdie72f8da32007-12-31 23:09:44 +0000274 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800275}
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100276EXPORT_SYMBOL_GPL(led_classdev_unregister);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800277
278static int __init leds_init(void)
279{
280 leds_class = class_create(THIS_MODULE, "leds");
281 if (IS_ERR(leds_class))
282 return PTR_ERR(leds_class);
Shuah Khan73e1ab42013-06-20 12:08:44 -0700283 leds_class->pm = &leds_class_dev_pm_ops;
Greg Kroah-Hartman5baa7502013-07-24 15:05:13 -0700284 leds_class->dev_groups = led_groups;
Richard Purdiec72a1d62006-03-31 02:31:04 -0800285 return 0;
286}
287
288static void __exit leds_exit(void)
289{
290 class_destroy(leds_class);
291}
292
293subsys_initcall(leds_init);
294module_exit(leds_exit);
295
296MODULE_AUTHOR("John Lenz, Richard Purdie");
297MODULE_LICENSE("GPL");
298MODULE_DESCRIPTION("LED Class Interface");