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");