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
)
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
);
110 write_unlock_irqrestore(&led_cdev
->trigger
->leddev_list_lock
,
112 if (led_cdev
->trigger
->deactivate
)
113 led_cdev
->trigger
->deactivate(led_cdev
);
114 led_cdev
->trigger
= NULL
;
115 led_set_brightness(led_cdev
, LED_OFF
);
118 write_lock_irqsave(&trig
->leddev_list_lock
, flags
);
119 list_add_tail(&led_cdev
->trig_list
, &trig
->led_cdevs
);
120 write_unlock_irqrestore(&trig
->leddev_list_lock
, flags
);
121 led_cdev
->trigger
= trig
;
123 trig
->activate(led_cdev
);
126 EXPORT_SYMBOL_GPL(led_trigger_set
);
128 void led_trigger_remove(struct led_classdev
*led_cdev
)
130 down_write(&led_cdev
->trigger_lock
);
131 led_trigger_set(led_cdev
, NULL
);
132 up_write(&led_cdev
->trigger_lock
);
134 EXPORT_SYMBOL_GPL(led_trigger_remove
);
136 void led_trigger_set_default(struct led_classdev
*led_cdev
)
138 struct led_trigger
*trig
;
140 if (!led_cdev
->default_trigger
)
143 down_read(&triggers_list_lock
);
144 down_write(&led_cdev
->trigger_lock
);
145 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
);
149 up_write(&led_cdev
->trigger_lock
);
150 up_read(&triggers_list_lock
);
152 EXPORT_SYMBOL_GPL(led_trigger_set_default
);
154 /* LED Trigger Interface */
156 int led_trigger_register(struct led_trigger
*trig
)
158 struct led_classdev
*led_cdev
;
159 struct led_trigger
*_trig
;
161 rwlock_init(&trig
->leddev_list_lock
);
162 INIT_LIST_HEAD(&trig
->led_cdevs
);
164 down_write(&triggers_list_lock
);
165 /* 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
, trig
->name
)) {
168 up_write(&triggers_list_lock
);
172 /* Add to the list of led triggers */
173 list_add_tail(&trig
->next_trig
, &trigger_list
);
174 up_write(&triggers_list_lock
);
176 /* Register with any LEDs that have this as a default trigger */
177 down_read(&leds_list_lock
);
178 list_for_each_entry(led_cdev
, &leds_list
, node
) {
179 down_write(&led_cdev
->trigger_lock
);
180 if (!led_cdev
->trigger
&& led_cdev
->default_trigger
&&
181 !strcmp(led_cdev
->default_trigger
, trig
->name
))
182 led_trigger_set(led_cdev
, trig
);
183 up_write(&led_cdev
->trigger_lock
);
185 up_read(&leds_list_lock
);
189 EXPORT_SYMBOL_GPL(led_trigger_register
);
191 void led_trigger_unregister(struct led_trigger
*trig
)
193 struct led_classdev
*led_cdev
;
195 /* Remove from the list of led triggers */
196 down_write(&triggers_list_lock
);
197 list_del(&trig
->next_trig
);
198 up_write(&triggers_list_lock
);
200 /* Remove anyone actively using this trigger */
201 down_read(&leds_list_lock
);
202 list_for_each_entry(led_cdev
, &leds_list
, node
) {
203 down_write(&led_cdev
->trigger_lock
);
204 if (led_cdev
->trigger
== trig
)
205 led_trigger_set(led_cdev
, NULL
);
206 up_write(&led_cdev
->trigger_lock
);
208 up_read(&leds_list_lock
);
210 EXPORT_SYMBOL_GPL(led_trigger_unregister
);
212 /* Simple LED Tigger Interface */
214 void led_trigger_event(struct led_trigger
*trig
,
215 enum led_brightness brightness
)
217 struct list_head
*entry
;
222 read_lock(&trig
->leddev_list_lock
);
223 list_for_each(entry
, &trig
->led_cdevs
) {
224 struct led_classdev
*led_cdev
;
226 led_cdev
= list_entry(entry
, struct led_classdev
, trig_list
);
227 led_set_brightness(led_cdev
, brightness
);
229 read_unlock(&trig
->leddev_list_lock
);
231 EXPORT_SYMBOL_GPL(led_trigger_event
);
233 static void led_trigger_blink_setup(struct led_trigger
*trig
,
234 unsigned long *delay_on
,
235 unsigned long *delay_off
,
239 struct list_head
*entry
;
244 read_lock(&trig
->leddev_list_lock
);
245 list_for_each(entry
, &trig
->led_cdevs
) {
246 struct led_classdev
*led_cdev
;
248 led_cdev
= list_entry(entry
, struct led_classdev
, trig_list
);
250 led_blink_set_oneshot(led_cdev
, delay_on
, delay_off
,
253 led_blink_set(led_cdev
, delay_on
, delay_off
);
255 read_unlock(&trig
->leddev_list_lock
);
258 void led_trigger_blink(struct led_trigger
*trig
,
259 unsigned long *delay_on
,
260 unsigned long *delay_off
)
262 led_trigger_blink_setup(trig
, delay_on
, delay_off
, 0, 0);
264 EXPORT_SYMBOL_GPL(led_trigger_blink
);
266 void led_trigger_blink_oneshot(struct led_trigger
*trig
,
267 unsigned long *delay_on
,
268 unsigned long *delay_off
,
271 led_trigger_blink_setup(trig
, delay_on
, delay_off
, 1, invert
);
273 EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot
);
275 void led_trigger_register_simple(const char *name
, struct led_trigger
**tp
)
277 struct led_trigger
*trig
;
280 trig
= kzalloc(sizeof(struct led_trigger
), GFP_KERNEL
);
284 err
= led_trigger_register(trig
);
288 printk(KERN_WARNING
"LED trigger %s failed to register"
289 " (%d)\n", name
, err
);
292 printk(KERN_WARNING
"LED trigger %s failed to register"
293 " (no memory)\n", name
);
297 EXPORT_SYMBOL_GPL(led_trigger_register_simple
);
299 void led_trigger_unregister_simple(struct led_trigger
*trig
)
302 led_trigger_unregister(trig
);
305 EXPORT_SYMBOL_GPL(led_trigger_unregister_simple
);
307 MODULE_AUTHOR("Richard Purdie");
308 MODULE_LICENSE("GPL");
309 MODULE_DESCRIPTION("LED Triggers Core");