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[people/arne_f/kernel.git] / drivers / leds / led-triggers.c
CommitLineData
c3bc9956
RP
1/*
2 * LED Triggers Core
3 *
f8a7c6fe 4 * Copyright 2005-2007 Openedhand Ltd.
c3bc9956
RP
5 *
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
50237863 14#include <linux/export.h>
c3bc9956 15#include <linux/kernel.h>
c3bc9956
RP
16#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <linux/device.h>
c3bc9956 19#include <linux/timer.h>
dc47206e 20#include <linux/rwsem.h>
c3bc9956 21#include <linux/leds.h>
5a0e3ad6 22#include <linux/slab.h>
c3bc9956
RP
23#include "leds.h"
24
25/*
26 * Nests outside led_cdev->trigger_lock
27 */
dc47206e 28static DECLARE_RWSEM(triggers_list_lock);
ba93cdce 29LIST_HEAD(trigger_list);
c3bc9956 30
4d404fd5
NM
31 /* Used by LED Class */
32
f8a7c6fe
RP
33ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
34 const char *buf, size_t count)
c3bc9956 35{
f8a7c6fe 36 struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956 37 struct led_trigger *trig;
acd899e4
JA
38 int ret = count;
39
40 mutex_lock(&led_cdev->led_access);
41
42 if (led_sysfs_is_disabled(led_cdev)) {
43 ret = -EBUSY;
44 goto unlock;
45 }
c3bc9956 46
7296c33e 47 if (sysfs_streq(buf, "none")) {
0013b23d 48 led_trigger_remove(led_cdev);
acd899e4 49 goto unlock;
c3bc9956
RP
50 }
51
dc47206e 52 down_read(&triggers_list_lock);
c3bc9956 53 list_for_each_entry(trig, &trigger_list, next_trig) {
7296c33e 54 if (sysfs_streq(buf, trig->name)) {
dc47206e 55 down_write(&led_cdev->trigger_lock);
c3bc9956 56 led_trigger_set(led_cdev, trig);
dc47206e 57 up_write(&led_cdev->trigger_lock);
c3bc9956 58
dc47206e 59 up_read(&triggers_list_lock);
acd899e4 60 goto unlock;
c3bc9956
RP
61 }
62 }
a3eac76c
HK
63 /* we come here only if buf matches no trigger */
64 ret = -EINVAL;
dc47206e 65 up_read(&triggers_list_lock);
c3bc9956 66
acd899e4
JA
67unlock:
68 mutex_unlock(&led_cdev->led_access);
69 return ret;
c3bc9956 70}
4d404fd5 71EXPORT_SYMBOL_GPL(led_trigger_store);
c3bc9956 72
f8a7c6fe
RP
73ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
74 char *buf)
c3bc9956 75{
f8a7c6fe 76 struct led_classdev *led_cdev = dev_get_drvdata(dev);
c3bc9956
RP
77 struct led_trigger *trig;
78 int len = 0;
79
dc47206e
RP
80 down_read(&triggers_list_lock);
81 down_read(&led_cdev->trigger_lock);
c3bc9956
RP
82
83 if (!led_cdev->trigger)
3b9b9536 84 len += scnprintf(buf+len, PAGE_SIZE - len, "[none] ");
c3bc9956 85 else
3b9b9536 86 len += scnprintf(buf+len, PAGE_SIZE - len, "none ");
c3bc9956
RP
87
88 list_for_each_entry(trig, &trigger_list, next_trig) {
89 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
90 trig->name))
3b9b9536
NS
91 len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ",
92 trig->name);
c3bc9956 93 else
3b9b9536
NS
94 len += scnprintf(buf+len, PAGE_SIZE - len, "%s ",
95 trig->name);
c3bc9956 96 }
dc47206e
RP
97 up_read(&led_cdev->trigger_lock);
98 up_read(&triggers_list_lock);
c3bc9956 99
3b9b9536 100 len += scnprintf(len+buf, PAGE_SIZE - len, "\n");
c3bc9956
RP
101 return len;
102}
4d404fd5 103EXPORT_SYMBOL_GPL(led_trigger_show);
c3bc9956
RP
104
105/* Caller must ensure led_cdev->trigger_lock held */
eb202621 106void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
c3bc9956
RP
107{
108 unsigned long flags;
52c47742
CC
109 char *event = NULL;
110 char *envp[2];
111 const char *name;
112
fbfa197a
JA
113 if (!led_cdev->trigger && !trig)
114 return;
115
52c47742
CC
116 name = trig ? trig->name : "none";
117 event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
c3bc9956
RP
118
119 /* Remove any existing trigger */
120 if (led_cdev->trigger) {
121 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
122 list_del(&led_cdev->trig_list);
4d404fd5
NM
123 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
124 flags);
d23a22a7
FB
125 cancel_work_sync(&led_cdev->set_brightness_work);
126 led_stop_software_blink(led_cdev);
c3bc9956
RP
127 if (led_cdev->trigger->deactivate)
128 led_cdev->trigger->deactivate(led_cdev);
fe3025b5 129 led_cdev->trigger = NULL;
19cd67e2 130 led_set_brightness(led_cdev, LED_OFF);
c3bc9956 131 }
eb202621
BW
132 if (trig) {
133 write_lock_irqsave(&trig->leddev_list_lock, flags);
134 list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
135 write_unlock_irqrestore(&trig->leddev_list_lock, flags);
136 led_cdev->trigger = trig;
137 if (trig->activate)
138 trig->activate(led_cdev);
c3bc9956 139 }
52c47742
CC
140
141 if (event) {
142 envp[0] = event;
143 envp[1] = NULL;
6f3bad96
JA
144 if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
145 dev_err(led_cdev->dev,
146 "%s: Error sending uevent\n", __func__);
52c47742
CC
147 kfree(event);
148 }
c3bc9956 149}
4d404fd5 150EXPORT_SYMBOL_GPL(led_trigger_set);
c3bc9956 151
0013b23d
NM
152void led_trigger_remove(struct led_classdev *led_cdev)
153{
154 down_write(&led_cdev->trigger_lock);
155 led_trigger_set(led_cdev, NULL);
156 up_write(&led_cdev->trigger_lock);
157}
4d404fd5 158EXPORT_SYMBOL_GPL(led_trigger_remove);
0013b23d 159
c3bc9956
RP
160void led_trigger_set_default(struct led_classdev *led_cdev)
161{
162 struct led_trigger *trig;
163
164 if (!led_cdev->default_trigger)
165 return;
166
dc47206e
RP
167 down_read(&triggers_list_lock);
168 down_write(&led_cdev->trigger_lock);
c3bc9956
RP
169 list_for_each_entry(trig, &trigger_list, next_trig) {
170 if (!strcmp(led_cdev->default_trigger, trig->name))
171 led_trigger_set(led_cdev, trig);
172 }
dc47206e
RP
173 up_write(&led_cdev->trigger_lock);
174 up_read(&triggers_list_lock);
c3bc9956 175}
4d404fd5
NM
176EXPORT_SYMBOL_GPL(led_trigger_set_default);
177
a8df7b1a
FB
178void led_trigger_rename_static(const char *name, struct led_trigger *trig)
179{
180 /* new name must be on a temporary string to prevent races */
181 BUG_ON(name == trig->name);
182
183 down_write(&triggers_list_lock);
184 /* this assumes that trig->name was originaly allocated to
185 * non constant storage */
186 strcpy((char *)trig->name, name);
187 up_write(&triggers_list_lock);
188}
189EXPORT_SYMBOL_GPL(led_trigger_rename_static);
190
4d404fd5 191/* LED Trigger Interface */
c3bc9956 192
eb202621 193int led_trigger_register(struct led_trigger *trig)
c3bc9956
RP
194{
195 struct led_classdev *led_cdev;
eb202621 196 struct led_trigger *_trig;
c3bc9956 197
eb202621
BW
198 rwlock_init(&trig->leddev_list_lock);
199 INIT_LIST_HEAD(&trig->led_cdevs);
c3bc9956 200
dc47206e 201 down_write(&triggers_list_lock);
700c6ea2 202 /* Make sure the trigger's name isn't already in use */
eb202621
BW
203 list_for_each_entry(_trig, &trigger_list, next_trig) {
204 if (!strcmp(_trig->name, trig->name)) {
700c6ea2
AN
205 up_write(&triggers_list_lock);
206 return -EEXIST;
207 }
208 }
209 /* Add to the list of led triggers */
eb202621 210 list_add_tail(&trig->next_trig, &trigger_list);
dc47206e 211 up_write(&triggers_list_lock);
c3bc9956
RP
212
213 /* Register with any LEDs that have this as a default trigger */
72f8da32 214 down_read(&leds_list_lock);
c3bc9956 215 list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e 216 down_write(&led_cdev->trigger_lock);
c3bc9956 217 if (!led_cdev->trigger && led_cdev->default_trigger &&
eb202621
BW
218 !strcmp(led_cdev->default_trigger, trig->name))
219 led_trigger_set(led_cdev, trig);
dc47206e 220 up_write(&led_cdev->trigger_lock);
c3bc9956 221 }
72f8da32 222 up_read(&leds_list_lock);
c3bc9956
RP
223
224 return 0;
225}
4d404fd5 226EXPORT_SYMBOL_GPL(led_trigger_register);
c3bc9956 227
eb202621 228void led_trigger_unregister(struct led_trigger *trig)
c3bc9956
RP
229{
230 struct led_classdev *led_cdev;
231
14f5716b
SL
232 if (list_empty_careful(&trig->next_trig))
233 return;
234
c3bc9956 235 /* Remove from the list of led triggers */
dc47206e 236 down_write(&triggers_list_lock);
14f5716b 237 list_del_init(&trig->next_trig);
dc47206e 238 up_write(&triggers_list_lock);
c3bc9956
RP
239
240 /* Remove anyone actively using this trigger */
72f8da32 241 down_read(&leds_list_lock);
c3bc9956 242 list_for_each_entry(led_cdev, &leds_list, node) {
dc47206e 243 down_write(&led_cdev->trigger_lock);
eb202621 244 if (led_cdev->trigger == trig)
c3bc9956 245 led_trigger_set(led_cdev, NULL);
dc47206e 246 up_write(&led_cdev->trigger_lock);
c3bc9956 247 }
72f8da32 248 up_read(&leds_list_lock);
c3bc9956 249}
4d404fd5 250EXPORT_SYMBOL_GPL(led_trigger_unregister);
c3bc9956 251
9534cc31
HK
252static void devm_led_trigger_release(struct device *dev, void *res)
253{
254 led_trigger_unregister(*(struct led_trigger **)res);
255}
256
257int devm_led_trigger_register(struct device *dev,
258 struct led_trigger *trig)
259{
260 struct led_trigger **dr;
261 int rc;
262
263 dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
264 GFP_KERNEL);
265 if (!dr)
266 return -ENOMEM;
267
268 *dr = trig;
269
270 rc = led_trigger_register(trig);
271 if (rc)
272 devres_free(dr);
273 else
274 devres_add(dev, dr);
275
276 return rc;
277}
278EXPORT_SYMBOL_GPL(devm_led_trigger_register);
279
4d404fd5
NM
280/* Simple LED Tigger Interface */
281
eb202621 282void led_trigger_event(struct led_trigger *trig,
4d404fd5 283 enum led_brightness brightness)
c3bc9956 284{
11e043b5 285 struct led_classdev *led_cdev;
4d404fd5 286
eb202621 287 if (!trig)
4d404fd5
NM
288 return;
289
eb202621 290 read_lock(&trig->leddev_list_lock);
11e043b5 291 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
d23a22a7 292 led_set_brightness(led_cdev, brightness);
eb202621 293 read_unlock(&trig->leddev_list_lock);
c3bc9956 294}
4d404fd5 295EXPORT_SYMBOL_GPL(led_trigger_event);
c3bc9956 296
20c0e6b8 297static void led_trigger_blink_setup(struct led_trigger *trig,
5bb629c5
FB
298 unsigned long *delay_on,
299 unsigned long *delay_off,
300 int oneshot,
301 int invert)
0b9536c9 302{
11e043b5 303 struct led_classdev *led_cdev;
0b9536c9 304
eb202621 305 if (!trig)
0b9536c9
VK
306 return;
307
eb202621 308 read_lock(&trig->leddev_list_lock);
11e043b5 309 list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
5bb629c5
FB
310 if (oneshot)
311 led_blink_set_oneshot(led_cdev, delay_on, delay_off,
312 invert);
313 else
314 led_blink_set(led_cdev, delay_on, delay_off);
0b9536c9 315 }
eb202621 316 read_unlock(&trig->leddev_list_lock);
0b9536c9 317}
5bb629c5
FB
318
319void led_trigger_blink(struct led_trigger *trig,
320 unsigned long *delay_on,
321 unsigned long *delay_off)
322{
323 led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
324}
0b9536c9
VK
325EXPORT_SYMBOL_GPL(led_trigger_blink);
326
5bb629c5
FB
327void led_trigger_blink_oneshot(struct led_trigger *trig,
328 unsigned long *delay_on,
329 unsigned long *delay_off,
330 int invert)
331{
332 led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
333}
334EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
335
4d404fd5
NM
336void led_trigger_register_simple(const char *name, struct led_trigger **tp)
337{
eb202621 338 struct led_trigger *trig;
4d404fd5 339 int err;
c3bc9956 340
eb202621 341 trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
c3bc9956 342
eb202621
BW
343 if (trig) {
344 trig->name = name;
345 err = led_trigger_register(trig);
cba4c2ac 346 if (err < 0) {
eb202621
BW
347 kfree(trig);
348 trig = NULL;
09f5fe75
SK
349 pr_warn("LED trigger %s failed to register (%d)\n",
350 name, err);
cba4c2ac 351 }
09f5fe75
SK
352 } else {
353 pr_warn("LED trigger %s failed to register (no memory)\n",
354 name);
355 }
eb202621 356 *tp = trig;
4d404fd5 357}
c3bc9956 358EXPORT_SYMBOL_GPL(led_trigger_register_simple);
4d404fd5 359
eb202621 360void led_trigger_unregister_simple(struct led_trigger *trig)
4d404fd5 361{
eb202621
BW
362 if (trig)
363 led_trigger_unregister(trig);
364 kfree(trig);
4d404fd5 365}
c3bc9956 366EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);