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Richard Purdiec3bc9952006-03-31 02:31:05 -08001/*
2 * LED Triggers Core
3 *
Richard Purdief8a7c6f2007-07-08 23:19:31 +01004 * Copyright 2005-2007 Openedhand Ltd.
Richard Purdiec3bc9952006-03-31 02:31:05 -08005 *
6 * Author: Richard Purdie <rpurdie@openedhand.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
Richard Purdiec3bc9952006-03-31 02:31:05 -080014#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/list.h>
18#include <linux/spinlock.h>
19#include <linux/device.h>
20#include <linux/sysdev.h>
21#include <linux/timer.h>
Richard Purdiedc472062007-11-10 13:29:04 +000022#include <linux/rwsem.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080023#include <linux/leds.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
Richard Purdiec3bc9952006-03-31 02:31:05 -080025#include "leds.h"
26
27/*
28 * Nests outside led_cdev->trigger_lock
29 */
Richard Purdiedc472062007-11-10 13:29:04 +000030static DECLARE_RWSEM(triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080031static LIST_HEAD(trigger_list);
32
Németh Márton4d404fd2008-03-09 20:59:57 +000033 /* Used by LED Class */
34
Richard Purdief8a7c6f2007-07-08 23:19:31 +010035ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
36 const char *buf, size_t count)
Richard Purdiec3bc9952006-03-31 02:31:05 -080037{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010038 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080039 char trigger_name[TRIG_NAME_MAX];
40 struct led_trigger *trig;
41 size_t len;
42
43 trigger_name[sizeof(trigger_name) - 1] = '\0';
44 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
45 len = strlen(trigger_name);
46
47 if (len && trigger_name[len - 1] == '\n')
48 trigger_name[len - 1] = '\0';
49
50 if (!strcmp(trigger_name, "none")) {
Németh Márton0013b232008-03-09 20:54:37 +000051 led_trigger_remove(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080052 return count;
53 }
54
Richard Purdiedc472062007-11-10 13:29:04 +000055 down_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080056 list_for_each_entry(trig, &trigger_list, next_trig) {
57 if (!strcmp(trigger_name, trig->name)) {
Richard Purdiedc472062007-11-10 13:29:04 +000058 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080059 led_trigger_set(led_cdev, trig);
Richard Purdiedc472062007-11-10 13:29:04 +000060 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080061
Richard Purdiedc472062007-11-10 13:29:04 +000062 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080063 return count;
64 }
65 }
Richard Purdiedc472062007-11-10 13:29:04 +000066 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080067
68 return -EINVAL;
69}
Németh Márton4d404fd2008-03-09 20:59:57 +000070EXPORT_SYMBOL_GPL(led_trigger_store);
Richard Purdiec3bc9952006-03-31 02:31:05 -080071
Richard Purdief8a7c6f2007-07-08 23:19:31 +010072ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
73 char *buf)
Richard Purdiec3bc9952006-03-31 02:31:05 -080074{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010075 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080076 struct led_trigger *trig;
77 int len = 0;
78
Richard Purdiedc472062007-11-10 13:29:04 +000079 down_read(&triggers_list_lock);
80 down_read(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080081
82 if (!led_cdev->trigger)
83 len += sprintf(buf+len, "[none] ");
84 else
85 len += sprintf(buf+len, "none ");
86
87 list_for_each_entry(trig, &trigger_list, next_trig) {
88 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
89 trig->name))
90 len += sprintf(buf+len, "[%s] ", trig->name);
91 else
92 len += sprintf(buf+len, "%s ", trig->name);
93 }
Richard Purdiedc472062007-11-10 13:29:04 +000094 up_read(&led_cdev->trigger_lock);
95 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080096
97 len += sprintf(len+buf, "\n");
98 return len;
99}
Németh Márton4d404fd2008-03-09 20:59:57 +0000100EXPORT_SYMBOL_GPL(led_trigger_show);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800101
102/* Caller must ensure led_cdev->trigger_lock held */
103void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
104{
105 unsigned long flags;
106
107 /* Remove any existing trigger */
108 if (led_cdev->trigger) {
109 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
110 list_del(&led_cdev->trig_list);
Németh Márton4d404fd2008-03-09 20:59:57 +0000111 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
112 flags);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800113 if (led_cdev->trigger->deactivate)
114 led_cdev->trigger->deactivate(led_cdev);
Dmitry Baryshkovfe3025b2008-07-16 22:51:14 +0100115 led_cdev->trigger = NULL;
Johannes Berg5ada28b2010-11-11 14:05:21 -0800116 led_brightness_set(led_cdev, LED_OFF);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800117 }
118 if (trigger) {
119 write_lock_irqsave(&trigger->leddev_list_lock, flags);
120 list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
121 write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
Dmitry Baryshkovfe3025b2008-07-16 22:51:14 +0100122 led_cdev->trigger = trigger;
Richard Purdiec3bc9952006-03-31 02:31:05 -0800123 if (trigger->activate)
124 trigger->activate(led_cdev);
125 }
Richard Purdiec3bc9952006-03-31 02:31:05 -0800126}
Németh Márton4d404fd2008-03-09 20:59:57 +0000127EXPORT_SYMBOL_GPL(led_trigger_set);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800128
Németh Márton0013b232008-03-09 20:54:37 +0000129void led_trigger_remove(struct led_classdev *led_cdev)
130{
131 down_write(&led_cdev->trigger_lock);
132 led_trigger_set(led_cdev, NULL);
133 up_write(&led_cdev->trigger_lock);
134}
Németh Márton4d404fd2008-03-09 20:59:57 +0000135EXPORT_SYMBOL_GPL(led_trigger_remove);
Németh Márton0013b232008-03-09 20:54:37 +0000136
Richard Purdiec3bc9952006-03-31 02:31:05 -0800137void led_trigger_set_default(struct led_classdev *led_cdev)
138{
139 struct led_trigger *trig;
140
141 if (!led_cdev->default_trigger)
142 return;
143
Richard Purdiedc472062007-11-10 13:29:04 +0000144 down_read(&triggers_list_lock);
145 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800146 list_for_each_entry(trig, &trigger_list, next_trig) {
147 if (!strcmp(led_cdev->default_trigger, trig->name))
148 led_trigger_set(led_cdev, trig);
149 }
Richard Purdiedc472062007-11-10 13:29:04 +0000150 up_write(&led_cdev->trigger_lock);
151 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800152}
Németh Márton4d404fd2008-03-09 20:59:57 +0000153EXPORT_SYMBOL_GPL(led_trigger_set_default);
154
155/* LED Trigger Interface */
Richard Purdiec3bc9952006-03-31 02:31:05 -0800156
157int led_trigger_register(struct led_trigger *trigger)
158{
159 struct led_classdev *led_cdev;
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000160 struct led_trigger *trig;
Richard Purdiec3bc9952006-03-31 02:31:05 -0800161
162 rwlock_init(&trigger->leddev_list_lock);
163 INIT_LIST_HEAD(&trigger->led_cdevs);
164
Richard Purdiedc472062007-11-10 13:29:04 +0000165 down_write(&triggers_list_lock);
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000166 /* Make sure the trigger's name isn't already in use */
167 list_for_each_entry(trig, &trigger_list, next_trig) {
168 if (!strcmp(trig->name, trigger->name)) {
169 up_write(&triggers_list_lock);
170 return -EEXIST;
171 }
172 }
173 /* Add to the list of led triggers */
Richard Purdiec3bc9952006-03-31 02:31:05 -0800174 list_add_tail(&trigger->next_trig, &trigger_list);
Richard Purdiedc472062007-11-10 13:29:04 +0000175 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800176
177 /* Register with any LEDs that have this as a default trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000178 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800179 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000180 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800181 if (!led_cdev->trigger && led_cdev->default_trigger &&
182 !strcmp(led_cdev->default_trigger, trigger->name))
183 led_trigger_set(led_cdev, trigger);
Richard Purdiedc472062007-11-10 13:29:04 +0000184 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800185 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000186 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800187
188 return 0;
189}
Németh Márton4d404fd2008-03-09 20:59:57 +0000190EXPORT_SYMBOL_GPL(led_trigger_register);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800191
192void led_trigger_unregister(struct led_trigger *trigger)
193{
194 struct led_classdev *led_cdev;
195
196 /* Remove from the list of led triggers */
Richard Purdiedc472062007-11-10 13:29:04 +0000197 down_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800198 list_del(&trigger->next_trig);
Richard Purdiedc472062007-11-10 13:29:04 +0000199 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800200
201 /* Remove anyone actively using this trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000202 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800203 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000204 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800205 if (led_cdev->trigger == trigger)
206 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000207 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800208 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000209 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800210}
Németh Márton4d404fd2008-03-09 20:59:57 +0000211EXPORT_SYMBOL_GPL(led_trigger_unregister);
212
213/* Simple LED Tigger Interface */
214
215void led_trigger_event(struct led_trigger *trigger,
216 enum led_brightness brightness)
217{
218 struct list_head *entry;
219
220 if (!trigger)
221 return;
222
223 read_lock(&trigger->leddev_list_lock);
224 list_for_each(entry, &trigger->led_cdevs) {
225 struct led_classdev *led_cdev;
226
227 led_cdev = list_entry(entry, struct led_classdev, trig_list);
228 led_set_brightness(led_cdev, brightness);
229 }
230 read_unlock(&trigger->leddev_list_lock);
231}
232EXPORT_SYMBOL_GPL(led_trigger_event);
233
234void led_trigger_register_simple(const char *name, struct led_trigger **tp)
235{
236 struct led_trigger *trigger;
237 int err;
238
239 trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
240
241 if (trigger) {
242 trigger->name = name;
243 err = led_trigger_register(trigger);
244 if (err < 0)
245 printk(KERN_WARNING "LED trigger %s failed to register"
246 " (%d)\n", name, err);
247 } else
248 printk(KERN_WARNING "LED trigger %s failed to register"
249 " (no memory)\n", name);
250
251 *tp = trigger;
252}
253EXPORT_SYMBOL_GPL(led_trigger_register_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800254
255void led_trigger_unregister_simple(struct led_trigger *trigger)
256{
Richard Purdie3593a6d2007-05-10 23:46:30 +0100257 if (trigger)
258 led_trigger_unregister(trigger);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800259 kfree(trigger);
260}
Richard Purdiec3bc9952006-03-31 02:31:05 -0800261EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800262
263MODULE_AUTHOR("Richard Purdie");
264MODULE_LICENSE("GPL");
265MODULE_DESCRIPTION("LED Triggers Core");