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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>
24#include "leds.h"
25
26/*
27 * Nests outside led_cdev->trigger_lock
28 */
Richard Purdiedc472062007-11-10 13:29:04 +000029static DECLARE_RWSEM(triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080030static LIST_HEAD(trigger_list);
31
Németh Márton4d404fd2008-03-09 20:59:57 +000032 /* Used by LED Class */
33
Richard Purdief8a7c6f2007-07-08 23:19:31 +010034ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
35 const char *buf, size_t count)
Richard Purdiec3bc9952006-03-31 02:31:05 -080036{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010037 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080038 char trigger_name[TRIG_NAME_MAX];
39 struct led_trigger *trig;
40 size_t len;
41
42 trigger_name[sizeof(trigger_name) - 1] = '\0';
43 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
44 len = strlen(trigger_name);
45
46 if (len && trigger_name[len - 1] == '\n')
47 trigger_name[len - 1] = '\0';
48
49 if (!strcmp(trigger_name, "none")) {
Németh Márton0013b232008-03-09 20:54:37 +000050 led_trigger_remove(led_cdev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080051 return count;
52 }
53
Richard Purdiedc472062007-11-10 13:29:04 +000054 down_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080055 list_for_each_entry(trig, &trigger_list, next_trig) {
56 if (!strcmp(trigger_name, trig->name)) {
Richard Purdiedc472062007-11-10 13:29:04 +000057 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080058 led_trigger_set(led_cdev, trig);
Richard Purdiedc472062007-11-10 13:29:04 +000059 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080060
Richard Purdiedc472062007-11-10 13:29:04 +000061 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080062 return count;
63 }
64 }
Richard Purdiedc472062007-11-10 13:29:04 +000065 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080066
67 return -EINVAL;
68}
Németh Márton4d404fd2008-03-09 20:59:57 +000069EXPORT_SYMBOL_GPL(led_trigger_store);
Richard Purdiec3bc9952006-03-31 02:31:05 -080070
Richard Purdief8a7c6f2007-07-08 23:19:31 +010071ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
72 char *buf)
Richard Purdiec3bc9952006-03-31 02:31:05 -080073{
Richard Purdief8a7c6f2007-07-08 23:19:31 +010074 struct led_classdev *led_cdev = dev_get_drvdata(dev);
Richard Purdiec3bc9952006-03-31 02:31:05 -080075 struct led_trigger *trig;
76 int len = 0;
77
Richard Purdiedc472062007-11-10 13:29:04 +000078 down_read(&triggers_list_lock);
79 down_read(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080080
81 if (!led_cdev->trigger)
82 len += sprintf(buf+len, "[none] ");
83 else
84 len += sprintf(buf+len, "none ");
85
86 list_for_each_entry(trig, &trigger_list, next_trig) {
87 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
88 trig->name))
89 len += sprintf(buf+len, "[%s] ", trig->name);
90 else
91 len += sprintf(buf+len, "%s ", trig->name);
92 }
Richard Purdiedc472062007-11-10 13:29:04 +000093 up_read(&led_cdev->trigger_lock);
94 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -080095
96 len += sprintf(len+buf, "\n");
97 return len;
98}
Németh Márton4d404fd2008-03-09 20:59:57 +000099EXPORT_SYMBOL_GPL(led_trigger_show);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800100
101/* Caller must ensure led_cdev->trigger_lock held */
102void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
103{
104 unsigned long flags;
105
106 /* Remove any existing trigger */
107 if (led_cdev->trigger) {
108 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
109 list_del(&led_cdev->trig_list);
Németh Márton4d404fd2008-03-09 20:59:57 +0000110 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
111 flags);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800112 if (led_cdev->trigger->deactivate)
113 led_cdev->trigger->deactivate(led_cdev);
Dmitry Baryshkovfe3025b2008-07-16 22:51:14 +0100114 led_cdev->trigger = NULL;
Paul Collinse3e5fc92006-09-30 23:27:41 -0700115 led_set_brightness(led_cdev, LED_OFF);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800116 }
117 if (trigger) {
118 write_lock_irqsave(&trigger->leddev_list_lock, flags);
119 list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
120 write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
Dmitry Baryshkovfe3025b2008-07-16 22:51:14 +0100121 led_cdev->trigger = trigger;
Richard Purdiec3bc9952006-03-31 02:31:05 -0800122 if (trigger->activate)
123 trigger->activate(led_cdev);
124 }
Richard Purdiec3bc9952006-03-31 02:31:05 -0800125}
Németh Márton4d404fd2008-03-09 20:59:57 +0000126EXPORT_SYMBOL_GPL(led_trigger_set);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800127
Németh Márton0013b232008-03-09 20:54:37 +0000128void led_trigger_remove(struct led_classdev *led_cdev)
129{
130 down_write(&led_cdev->trigger_lock);
131 led_trigger_set(led_cdev, NULL);
132 up_write(&led_cdev->trigger_lock);
133}
Németh Márton4d404fd2008-03-09 20:59:57 +0000134EXPORT_SYMBOL_GPL(led_trigger_remove);
Németh Márton0013b232008-03-09 20:54:37 +0000135
Richard Purdiec3bc9952006-03-31 02:31:05 -0800136void led_trigger_set_default(struct led_classdev *led_cdev)
137{
138 struct led_trigger *trig;
139
140 if (!led_cdev->default_trigger)
141 return;
142
Richard Purdiedc472062007-11-10 13:29:04 +0000143 down_read(&triggers_list_lock);
144 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800145 list_for_each_entry(trig, &trigger_list, next_trig) {
146 if (!strcmp(led_cdev->default_trigger, trig->name))
147 led_trigger_set(led_cdev, trig);
148 }
Richard Purdiedc472062007-11-10 13:29:04 +0000149 up_write(&led_cdev->trigger_lock);
150 up_read(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800151}
Németh Márton4d404fd2008-03-09 20:59:57 +0000152EXPORT_SYMBOL_GPL(led_trigger_set_default);
153
154/* LED Trigger Interface */
Richard Purdiec3bc9952006-03-31 02:31:05 -0800155
156int led_trigger_register(struct led_trigger *trigger)
157{
158 struct led_classdev *led_cdev;
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000159 struct led_trigger *trig;
Richard Purdiec3bc9952006-03-31 02:31:05 -0800160
161 rwlock_init(&trigger->leddev_list_lock);
162 INIT_LIST_HEAD(&trigger->led_cdevs);
163
Richard Purdiedc472062007-11-10 13:29:04 +0000164 down_write(&triggers_list_lock);
Adam Nielsen700c6ea2009-02-18 08:18:04 +1000165 /* Make sure the trigger's name isn't already in use */
166 list_for_each_entry(trig, &trigger_list, next_trig) {
167 if (!strcmp(trig->name, trigger->name)) {
168 up_write(&triggers_list_lock);
169 return -EEXIST;
170 }
171 }
172 /* Add to the list of led triggers */
Richard Purdiec3bc9952006-03-31 02:31:05 -0800173 list_add_tail(&trigger->next_trig, &trigger_list);
Richard Purdiedc472062007-11-10 13:29:04 +0000174 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800175
176 /* Register with any LEDs that have this as a default trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000177 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800178 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000179 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800180 if (!led_cdev->trigger && led_cdev->default_trigger &&
181 !strcmp(led_cdev->default_trigger, trigger->name))
182 led_trigger_set(led_cdev, trigger);
Richard Purdiedc472062007-11-10 13:29:04 +0000183 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800184 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000185 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800186
187 return 0;
188}
Németh Márton4d404fd2008-03-09 20:59:57 +0000189EXPORT_SYMBOL_GPL(led_trigger_register);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800190
191void led_trigger_unregister(struct led_trigger *trigger)
192{
193 struct led_classdev *led_cdev;
194
195 /* Remove from the list of led triggers */
Richard Purdiedc472062007-11-10 13:29:04 +0000196 down_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800197 list_del(&trigger->next_trig);
Richard Purdiedc472062007-11-10 13:29:04 +0000198 up_write(&triggers_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800199
200 /* Remove anyone actively using this trigger */
Richard Purdie72f8da32007-12-31 23:09:44 +0000201 down_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800202 list_for_each_entry(led_cdev, &leds_list, node) {
Richard Purdiedc472062007-11-10 13:29:04 +0000203 down_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800204 if (led_cdev->trigger == trigger)
205 led_trigger_set(led_cdev, NULL);
Richard Purdiedc472062007-11-10 13:29:04 +0000206 up_write(&led_cdev->trigger_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800207 }
Richard Purdie72f8da32007-12-31 23:09:44 +0000208 up_read(&leds_list_lock);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800209}
Németh Márton4d404fd2008-03-09 20:59:57 +0000210EXPORT_SYMBOL_GPL(led_trigger_unregister);
211
212/* Simple LED Tigger Interface */
213
214void led_trigger_event(struct led_trigger *trigger,
215 enum led_brightness brightness)
216{
217 struct list_head *entry;
218
219 if (!trigger)
220 return;
221
222 read_lock(&trigger->leddev_list_lock);
223 list_for_each(entry, &trigger->led_cdevs) {
224 struct led_classdev *led_cdev;
225
226 led_cdev = list_entry(entry, struct led_classdev, trig_list);
227 led_set_brightness(led_cdev, brightness);
228 }
229 read_unlock(&trigger->leddev_list_lock);
230}
231EXPORT_SYMBOL_GPL(led_trigger_event);
232
233void led_trigger_register_simple(const char *name, struct led_trigger **tp)
234{
235 struct led_trigger *trigger;
236 int err;
237
238 trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
239
240 if (trigger) {
241 trigger->name = name;
242 err = led_trigger_register(trigger);
243 if (err < 0)
244 printk(KERN_WARNING "LED trigger %s failed to register"
245 " (%d)\n", name, err);
246 } else
247 printk(KERN_WARNING "LED trigger %s failed to register"
248 " (no memory)\n", name);
249
250 *tp = trigger;
251}
252EXPORT_SYMBOL_GPL(led_trigger_register_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800253
254void led_trigger_unregister_simple(struct led_trigger *trigger)
255{
Richard Purdie3593a6d2007-05-10 23:46:30 +0100256 if (trigger)
257 led_trigger_unregister(trigger);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800258 kfree(trigger);
259}
Richard Purdiec3bc9952006-03-31 02:31:05 -0800260EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
Richard Purdiec3bc9952006-03-31 02:31:05 -0800261
262MODULE_AUTHOR("Richard Purdie");
263MODULE_LICENSE("GPL");
264MODULE_DESCRIPTION("LED Triggers Core");