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