4 * Copyright 2005-2007 Openedhand Ltd.
6 * Author: Richard Purdie <rpurdie@openedhand.com>
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.
14 #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/timer.h>
21 #include <linux/rwsem.h>
22 #include <linux/leds.h>
23 #include <linux/slab.h>
27 * Nests outside led_cdev->trigger_lock
29 static DECLARE_RWSEM(triggers_list_lock);
30 static LIST_HEAD(trigger_list);
32 /* Used by LED Class */
34 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
35 const char *buf, size_t count)
37 struct led_classdev *led_cdev = dev_get_drvdata(dev);
38 char trigger_name[TRIG_NAME_MAX];
39 struct led_trigger *trig;
42 trigger_name[sizeof(trigger_name) - 1] = '\0';
43 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
44 len = strlen(trigger_name);
46 if (len && trigger_name[len - 1] == '\n')
47 trigger_name[len - 1] = '\0';
49 if (!strcmp(trigger_name, "none")) {
50 led_trigger_remove(led_cdev);
54 down_read(&triggers_list_lock);
55 list_for_each_entry(trig, &trigger_list, next_trig) {
56 if (!strcmp(trigger_name, trig->name)) {
57 down_write(&led_cdev->trigger_lock);
58 led_trigger_set(led_cdev, trig);
59 up_write(&led_cdev->trigger_lock);
61 up_read(&triggers_list_lock);
65 up_read(&triggers_list_lock);
69 EXPORT_SYMBOL_GPL(led_trigger_store);
71 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
74 struct led_classdev *led_cdev = dev_get_drvdata(dev);
75 struct led_trigger *trig;
78 down_read(&triggers_list_lock);
79 down_read(&led_cdev->trigger_lock);
81 if (!led_cdev->trigger)
82 len += sprintf(buf+len, "[none] ");
84 len += sprintf(buf+len, "none ");
86 list_for_each_entry(trig, &trigger_list, next_trig) {
87 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
89 len += sprintf(buf+len, "[%s] ", trig->name);
91 len += sprintf(buf+len, "%s ", trig->name);
93 up_read(&led_cdev->trigger_lock);
94 up_read(&triggers_list_lock);
96 len += sprintf(len+buf, "\n");
99 EXPORT_SYMBOL_GPL(led_trigger_show);
101 /* Caller must ensure led_cdev->trigger_lock held */
102 void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
109 name = trig ? trig->name : "none";
110 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
112 /* Remove any existing trigger */
113 if (led_cdev->trigger) {
114 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
115 list_del(&led_cdev->trig_list);
116 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
118 cancel_work_sync(&led_cdev->set_brightness_work);
119 led_stop_software_blink(led_cdev);
120 if (led_cdev->trigger->deactivate)
121 led_cdev->trigger->deactivate(led_cdev);
122 led_cdev->trigger = NULL;
123 led_set_brightness(led_cdev, LED_OFF);
126 write_lock_irqsave(&trig->leddev_list_lock, flags);
127 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
128 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
129 led_cdev->trigger = trig;
131 trig->activate(led_cdev);
137 kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
141 EXPORT_SYMBOL_GPL(led_trigger_set);
143 void led_trigger_remove(struct led_classdev *led_cdev)
145 down_write(&led_cdev->trigger_lock);
146 led_trigger_set(led_cdev, NULL);
147 up_write(&led_cdev->trigger_lock);
149 EXPORT_SYMBOL_GPL(led_trigger_remove);
151 void led_trigger_set_default(struct led_classdev *led_cdev)
153 struct led_trigger *trig;
155 if (!led_cdev->default_trigger)
158 down_read(&triggers_list_lock);
159 down_write(&led_cdev->trigger_lock);
160 list_for_each_entry(trig, &trigger_list, next_trig) {
161 if (!strcmp(led_cdev->default_trigger, trig->name))
162 led_trigger_set(led_cdev, trig);
164 up_write(&led_cdev->trigger_lock);
165 up_read(&triggers_list_lock);
167 EXPORT_SYMBOL_GPL(led_trigger_set_default);
169 /* LED Trigger Interface */
171 int led_trigger_register(struct led_trigger *trig)
173 struct led_classdev *led_cdev;
174 struct led_trigger *_trig;
176 rwlock_init(&trig->leddev_list_lock);
177 INIT_LIST_HEAD(&trig->led_cdevs);
179 down_write(&triggers_list_lock);
180 /* Make sure the trigger's name isn't already in use */
181 list_for_each_entry(_trig, &trigger_list, next_trig) {
182 if (!strcmp(_trig->name, trig->name)) {
183 up_write(&triggers_list_lock);
187 /* Add to the list of led triggers */
188 list_add_tail(&trig->next_trig, &trigger_list);
189 up_write(&triggers_list_lock);
191 /* Register with any LEDs that have this as a default trigger */
192 down_read(&leds_list_lock);
193 list_for_each_entry(led_cdev, &leds_list, node) {
194 down_write(&led_cdev->trigger_lock);
195 if (!led_cdev->trigger && led_cdev->default_trigger &&
196 !strcmp(led_cdev->default_trigger, trig->name))
197 led_trigger_set(led_cdev, trig);
198 up_write(&led_cdev->trigger_lock);
200 up_read(&leds_list_lock);
204 EXPORT_SYMBOL_GPL(led_trigger_register);
206 void led_trigger_unregister(struct led_trigger *trig)
208 struct led_classdev *led_cdev;
210 /* Remove from the list of led triggers */
211 down_write(&triggers_list_lock);
212 list_del(&trig->next_trig);
213 up_write(&triggers_list_lock);
215 /* Remove anyone actively using this trigger */
216 down_read(&leds_list_lock);
217 list_for_each_entry(led_cdev, &leds_list, node) {
218 down_write(&led_cdev->trigger_lock);
219 if (led_cdev->trigger == trig)
220 led_trigger_set(led_cdev, NULL);
221 up_write(&led_cdev->trigger_lock);
223 up_read(&leds_list_lock);
225 EXPORT_SYMBOL_GPL(led_trigger_unregister);
227 /* Simple LED Tigger Interface */
229 void led_trigger_event(struct led_trigger *trig,
230 enum led_brightness brightness)
232 struct list_head *entry;
237 read_lock(&trig->leddev_list_lock);
238 list_for_each(entry, &trig->led_cdevs) {
239 struct led_classdev *led_cdev;
241 led_cdev = list_entry(entry, struct led_classdev, trig_list);
242 led_set_brightness(led_cdev, brightness);
244 read_unlock(&trig->leddev_list_lock);
246 EXPORT_SYMBOL_GPL(led_trigger_event);
248 static void led_trigger_blink_setup(struct led_trigger *trig,
249 unsigned long *delay_on,
250 unsigned long *delay_off,
254 struct list_head *entry;
259 read_lock(&trig->leddev_list_lock);
260 list_for_each(entry, &trig->led_cdevs) {
261 struct led_classdev *led_cdev;
263 led_cdev = list_entry(entry, struct led_classdev, trig_list);
265 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
268 led_blink_set(led_cdev, delay_on, delay_off);
270 read_unlock(&trig->leddev_list_lock);
273 void led_trigger_blink(struct led_trigger *trig,
274 unsigned long *delay_on,
275 unsigned long *delay_off)
277 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
279 EXPORT_SYMBOL_GPL(led_trigger_blink);
281 void led_trigger_blink_oneshot(struct led_trigger *trig,
282 unsigned long *delay_on,
283 unsigned long *delay_off,
286 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
288 EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
290 void led_trigger_register_simple(const char *name, struct led_trigger **tp)
292 struct led_trigger *trig;
295 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
299 err = led_trigger_register(trig);
303 printk(KERN_WARNING "LED trigger %s failed to register"
304 " (%d)\n", name, err);
307 printk(KERN_WARNING "LED trigger %s failed to register"
308 " (no memory)\n", name);
312 EXPORT_SYMBOL_GPL(led_trigger_register_simple);
314 void led_trigger_unregister_simple(struct led_trigger *trig)
317 led_trigger_unregister(trig);
320 EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
322 MODULE_AUTHOR("Richard Purdie");
323 MODULE_LICENSE("GPL");
324 MODULE_DESCRIPTION("LED Triggers Core");