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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>
18#include <linux/sysdev.h>
19#include <linux/timer.h>
20#include <linux/err.h>
Richard Purdie3dc7b822006-05-15 09:44:17 -070021#include <linux/ctype.h>
Richard Purdiec72a1d62006-03-31 02:31:04 -080022#include <linux/leds.h>
23#include "leds.h"
24
25static struct class *leds_class;
26
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +000027static void led_update_brightness(struct led_classdev *led_cdev)
28{
29 if (led_cdev->brightness_get)
30 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
31}
32
Richard Purdief8a7c6f2007-07-08 23:19:31 +010033static ssize_t led_brightness_show(struct device *dev,
34 struct device_attribute *attr, char *buf)
Richard Purdiec72a1d62006-03-31 02:31:04 -080035{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010036 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080037
38 /* no lock needed for this */
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +000039 led_update_brightness(led_cdev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080040
Sven Wegenerdd8e5a22008-10-13 10:41:39 +010041 return sprintf(buf, "%u\n", led_cdev->brightness);
Richard Purdiec72a1d62006-03-31 02:31:04 -080042}
43
Richard Purdief8a7c6f2007-07-08 23:19:31 +010044static ssize_t led_brightness_store(struct device *dev,
45 struct device_attribute *attr, const char *buf, size_t size)
Richard Purdiec72a1d62006-03-31 02:31:04 -080046{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010047 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080048 ssize_t ret = -EINVAL;
49 char *after;
50 unsigned long state = simple_strtoul(buf, &after, 10);
Richard Purdie3dc7b822006-05-15 09:44:17 -070051 size_t count = after - buf;
Richard Purdiec72a1d62006-03-31 02:31:04 -080052
André Goddard Rosae7d28602009-12-14 18:01:06 -080053 if (isspace(*after))
Richard Purdie3dc7b822006-05-15 09:44:17 -070054 count++;
55
56 if (count == size) {
57 ret = count;
Németh Márton0013b232008-03-09 20:54:37 +000058
59 if (state == LED_OFF)
60 led_trigger_remove(led_cdev);
Richard Purdiec72a1d62006-03-31 02:31:04 -080061 led_set_brightness(led_cdev, state);
62 }
63
64 return ret;
65}
66
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +000067static ssize_t led_max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
71
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
73}
74
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010075static struct device_attribute led_class_attrs[] = {
76 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
Axel Lin569762e2010-05-17 08:48:28 +080077 __ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
Richard Purdiec3bc9952006-03-31 02:31:05 -080078#ifdef CONFIG_LEDS_TRIGGERS
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010079 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
Richard Purdiec3bc9952006-03-31 02:31:05 -080080#endif
Florian Fainelli14b5d6d2010-03-10 18:32:18 +010081 __ATTR_NULL,
82};
Richard Purdiec72a1d62006-03-31 02:31:04 -080083
Johannes Berg5ada28b2010-11-11 14:05:21 -080084static void led_timer_function(unsigned long data)
85{
86 struct led_classdev *led_cdev = (void *)data;
87 unsigned long brightness;
88 unsigned long delay;
89
90 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
91 led_set_brightness(led_cdev, LED_OFF);
92 return;
93 }
94
95 brightness = led_get_brightness(led_cdev);
96 if (!brightness) {
97 /* Time to switch the LED on. */
98 brightness = led_cdev->blink_brightness;
99 delay = led_cdev->blink_delay_on;
100 } else {
101 /* Store the current brightness value to be able
102 * to restore it when the delay_off period is over.
103 */
104 led_cdev->blink_brightness = brightness;
105 brightness = LED_OFF;
106 delay = led_cdev->blink_delay_off;
107 }
108
109 led_set_brightness(led_cdev, brightness);
110
111 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
112}
113
114static void led_stop_software_blink(struct led_classdev *led_cdev)
115{
116 /* deactivate previous settings */
117 del_timer_sync(&led_cdev->blink_timer);
118 led_cdev->blink_delay_on = 0;
119 led_cdev->blink_delay_off = 0;
120}
121
122static void led_set_software_blink(struct led_classdev *led_cdev,
123 unsigned long delay_on,
124 unsigned long delay_off)
125{
126 int current_brightness;
127
128 current_brightness = led_get_brightness(led_cdev);
129 if (current_brightness)
130 led_cdev->blink_brightness = current_brightness;
131 if (!led_cdev->blink_brightness)
132 led_cdev->blink_brightness = led_cdev->max_brightness;
133
134 if (delay_on == led_cdev->blink_delay_on &&
135 delay_off == led_cdev->blink_delay_off)
136 return;
137
138 led_stop_software_blink(led_cdev);
139
140 led_cdev->blink_delay_on = delay_on;
141 led_cdev->blink_delay_off = delay_off;
142
143 /* never on - don't blink */
144 if (!delay_on)
145 return;
146
147 /* never off - just set to brightness */
148 if (!delay_off) {
149 led_set_brightness(led_cdev, led_cdev->blink_brightness);
150 return;
151 }
152
153 mod_timer(&led_cdev->blink_timer, jiffies + 1);
154}
155
156
Richard Purdiec72a1d62006-03-31 02:31:04 -0800157/**
158 * led_classdev_suspend - suspend an led_classdev.
159 * @led_cdev: the led_classdev to suspend.
160 */
161void led_classdev_suspend(struct led_classdev *led_cdev)
162{
163 led_cdev->flags |= LED_SUSPENDED;
164 led_cdev->brightness_set(led_cdev, 0);
165}
166EXPORT_SYMBOL_GPL(led_classdev_suspend);
167
168/**
169 * led_classdev_resume - resume an led_classdev.
170 * @led_cdev: the led_classdev to resume.
171 */
172void led_classdev_resume(struct led_classdev *led_cdev)
173{
174 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
175 led_cdev->flags &= ~LED_SUSPENDED;
176}
177EXPORT_SYMBOL_GPL(led_classdev_resume);
178
Richard Purdie859cb7f2009-01-08 17:55:03 +0000179static int led_suspend(struct device *dev, pm_message_t state)
180{
181 struct led_classdev *led_cdev = dev_get_drvdata(dev);
182
183 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
184 led_classdev_suspend(led_cdev);
185
186 return 0;
187}
188
189static int led_resume(struct device *dev)
190{
191 struct led_classdev *led_cdev = dev_get_drvdata(dev);
192
193 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
194 led_classdev_resume(led_cdev);
195
196 return 0;
197}
198
Richard Purdiec72a1d62006-03-31 02:31:04 -0800199/**
200 * led_classdev_register - register a new object of led_classdev class.
Sven Wegenerff8649a2008-12-03 08:04:57 +0000201 * @parent: The device to register.
Richard Purdiec72a1d62006-03-31 02:31:04 -0800202 * @led_cdev: the led_classdev structure for this device.
203 */
204int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
205{
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700206 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
207 "%s", led_cdev->name);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700208 if (IS_ERR(led_cdev->dev))
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100209 return PTR_ERR(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800210
Richard Purdie270c3952008-10-20 23:16:17 +0100211#ifdef CONFIG_LEDS_TRIGGERS
212 init_rwsem(&led_cdev->trigger_lock);
213#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800214 /* add to the list of leds */
Richard Purdie72f8da32007-12-31 23:09:44 +0000215 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800216 list_add_tail(&led_cdev->node, &leds_list);
Richard Purdie72f8da32007-12-31 23:09:44 +0000217 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800218
Guennadi Liakhovetski1bd465e2009-01-10 18:54:39 +0000219 if (!led_cdev->max_brightness)
220 led_cdev->max_brightness = LED_FULL;
221
Henrique de Moraes Holschuh29d76df2008-03-18 09:47:48 +0000222 led_update_brightness(led_cdev);
223
Johannes Berg5ada28b2010-11-11 14:05:21 -0800224 init_timer(&led_cdev->blink_timer);
225 led_cdev->blink_timer.function = led_timer_function;
226 led_cdev->blink_timer.data = (unsigned long)led_cdev;
227
Richard Purdiec3bc9952006-03-31 02:31:05 -0800228#ifdef CONFIG_LEDS_TRIGGERS
Jeff Garzik12fda162006-10-17 00:10:20 -0700229 led_trigger_set_default(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800230#endif
231
H Hartley Sweetenbb9b6ef2010-01-06 15:34:55 -0700232 printk(KERN_DEBUG "Registered led device: %s\n",
Richard Purdief8a7c6f2007-07-08 23:19:31 +0100233 led_cdev->name);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800234
235 return 0;
236}
237EXPORT_SYMBOL_GPL(led_classdev_register);
238
239/**
Qinghuang Feng0266a452008-10-20 23:04:36 +0100240 * led_classdev_unregister - unregisters a object of led_properties class.
Henrik Kretzschmar70d63cc2006-10-03 23:31:30 +0200241 * @led_cdev: the led device to unregister
Richard Purdiec72a1d62006-03-31 02:31:04 -0800242 *
243 * Unregisters a previously registered via led_classdev_register object.
244 */
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100245void led_classdev_unregister(struct led_classdev *led_cdev)
Richard Purdiec72a1d62006-03-31 02:31:04 -0800246{
Richard Purdiec3bc9952006-03-31 02:31:05 -0800247#ifdef CONFIG_LEDS_TRIGGERS
Richard Purdiedc472062007-11-10 13:29:04 +0000248 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800249 if (led_cdev->trigger)
250 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000251 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800252#endif
Richard Purdiec72a1d62006-03-31 02:31:04 -0800253
Johannes Berg5ada28b2010-11-11 14:05:21 -0800254 /* Stop blinking */
255 led_brightness_set(led_cdev, LED_OFF);
256
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100257 device_unregister(led_cdev->dev);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800258
Richard Purdie72f8da32007-12-31 23:09:44 +0000259 down_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800260 list_del(&led_cdev->node);
Richard Purdie72f8da32007-12-31 23:09:44 +0000261 up_write(&leds_list_lock);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800262}
Rafael J. Wysockib844eba2008-03-23 20:28:24 +0100263EXPORT_SYMBOL_GPL(led_classdev_unregister);
Richard Purdiec72a1d62006-03-31 02:31:04 -0800264
Johannes Berg5ada28b2010-11-11 14:05:21 -0800265void led_blink_set(struct led_classdev *led_cdev,
266 unsigned long *delay_on,
267 unsigned long *delay_off)
268{
269 if (led_cdev->blink_set &&
Johannes Berg91facc22010-12-21 17:24:28 -0800270 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
Johannes Berg5ada28b2010-11-11 14:05:21 -0800271 return;
272
273 /* blink with 1 Hz as default if nothing specified */
274 if (!*delay_on && !*delay_off)
275 *delay_on = *delay_off = 500;
276
277 led_set_software_blink(led_cdev, *delay_on, *delay_off);
278}
279EXPORT_SYMBOL(led_blink_set);
280
281void led_brightness_set(struct led_classdev *led_cdev,
282 enum led_brightness brightness)
283{
284 led_stop_software_blink(led_cdev);
285 led_cdev->brightness_set(led_cdev, brightness);
286}
287EXPORT_SYMBOL(led_brightness_set);
288
Richard Purdiec72a1d62006-03-31 02:31:04 -0800289static int __init leds_init(void)
290{
291 leds_class = class_create(THIS_MODULE, "leds");
292 if (IS_ERR(leds_class))
293 return PTR_ERR(leds_class);
Richard Purdie859cb7f2009-01-08 17:55:03 +0000294 leds_class->suspend = led_suspend;
295 leds_class->resume = led_resume;
Florian Fainelli14b5d6d2010-03-10 18:32:18 +0100296 leds_class->dev_attrs = led_class_attrs;
Richard Purdiec72a1d62006-03-31 02:31:04 -0800297 return 0;
298}
299
300static void __exit leds_exit(void)
301{
302 class_destroy(leds_class);
303}
304
305subsys_initcall(leds_init);
306module_exit(leds_exit);
307
308MODULE_AUTHOR("John Lenz, Richard Purdie");
309MODULE_LICENSE("GPL");
310MODULE_DESCRIPTION("LED Class Interface");