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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/init.h>
17#include <linux/list.h>
18#include <linux/spinlock.h>
19#include <linux/device.h>
20#include <linux/sysdev.h>
21#include <linux/timer.h>
22#include <linux/rwsem.h>
23#include <linux/leds.h>
24#include <linux/slab.h>
25#include "leds.h"
26
27/*
28 * Nests outside led_cdev->trigger_lock
29 */
30static DECLARE_RWSEM(triggers_list_lock);
31static LIST_HEAD(trigger_list);
32
33 /* Used by LED Class */
34
35ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
36 const char *buf, size_t count)
37{
38 struct led_classdev *led_cdev = dev_get_drvdata(dev);
39 char trigger_name[TRIG_NAME_MAX];
40 struct led_trigger *trig;
41 size_t len;
42
43 trigger_name[sizeof(trigger_name) - 1] = '\0';
44 strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
45 len = strlen(trigger_name);
46
47 if (len && trigger_name[len - 1] == '\n')
48 trigger_name[len - 1] = '\0';
49
50 if (!strcmp(trigger_name, "none")) {
51 led_trigger_remove(led_cdev);
52 return count;
53 }
54
55 down_read(&triggers_list_lock);
56 list_for_each_entry(trig, &trigger_list, next_trig) {
57 if (!strcmp(trigger_name, trig->name)) {
58 down_write(&led_cdev->trigger_lock);
59 led_trigger_set(led_cdev, trig);
60 up_write(&led_cdev->trigger_lock);
61
62 up_read(&triggers_list_lock);
63 return count;
64 }
65 }
66 up_read(&triggers_list_lock);
67
68 return -EINVAL;
69}
70EXPORT_SYMBOL_GPL(led_trigger_store);
71
72ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
73 char *buf)
74{
75 struct led_classdev *led_cdev = dev_get_drvdata(dev);
76 struct led_trigger *trig;
77 int len = 0;
78
79 down_read(&triggers_list_lock);
80 down_read(&led_cdev->trigger_lock);
81
82 if (!led_cdev->trigger)
83 len += sprintf(buf+len, "[none] ");
84 else
85 len += sprintf(buf+len, "none ");
86
87 list_for_each_entry(trig, &trigger_list, next_trig) {
88 if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
89 trig->name))
90 len += sprintf(buf+len, "[%s] ", trig->name);
91 else
92 len += sprintf(buf+len, "%s ", trig->name);
93 }
94 up_read(&led_cdev->trigger_lock);
95 up_read(&triggers_list_lock);
96
97 len += sprintf(len+buf, "\n");
98 return len;
99}
100EXPORT_SYMBOL_GPL(led_trigger_show);
101
102/* Caller must ensure led_cdev->trigger_lock held */
103void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
104{
105 unsigned long flags;
106
107 /* Remove any existing trigger */
108 if (led_cdev->trigger) {
109 write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
110 list_del(&led_cdev->trig_list);
111 write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
112 flags);
113 if (led_cdev->trigger->deactivate)
114 led_cdev->trigger->deactivate(led_cdev);
115 led_cdev->trigger = NULL;
116 led_brightness_set(led_cdev, LED_OFF);
117 }
118 if (trigger) {
119 write_lock_irqsave(&trigger->leddev_list_lock, flags);
120 list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
121 write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
122 led_cdev->trigger = trigger;
123 if (trigger->activate)
124 trigger->activate(led_cdev);
125 }
126}
127EXPORT_SYMBOL_GPL(led_trigger_set);
128
129void led_trigger_remove(struct led_classdev *led_cdev)
130{
131 down_write(&led_cdev->trigger_lock);
132 led_trigger_set(led_cdev, NULL);
133 up_write(&led_cdev->trigger_lock);
134}
135EXPORT_SYMBOL_GPL(led_trigger_remove);
136
137void led_trigger_set_default(struct led_classdev *led_cdev)
138{
139 struct led_trigger *trig;
140
141 if (!led_cdev->default_trigger)
142 return;
143
144 down_read(&triggers_list_lock);
145 down_write(&led_cdev->trigger_lock);
146 list_for_each_entry(trig, &trigger_list, next_trig) {
147 if (!strcmp(led_cdev->default_trigger, trig->name))
148 led_trigger_set(led_cdev, trig);
149 }
150 up_write(&led_cdev->trigger_lock);
151 up_read(&triggers_list_lock);
152}
153EXPORT_SYMBOL_GPL(led_trigger_set_default);
154
155/* LED Trigger Interface */
156
157int led_trigger_register(struct led_trigger *trigger)
158{
159 struct led_classdev *led_cdev;
160 struct led_trigger *trig;
161
162 rwlock_init(&trigger->leddev_list_lock);
163 INIT_LIST_HEAD(&trigger->led_cdevs);
164
165 down_write(&triggers_list_lock);
166 /* Make sure the trigger's name isn't already in use */
167 list_for_each_entry(trig, &trigger_list, next_trig) {
168 if (!strcmp(trig->name, trigger->name)) {
169 up_write(&triggers_list_lock);
170 return -EEXIST;
171 }
172 }
173 /* Add to the list of led triggers */
174 list_add_tail(&trigger->next_trig, &trigger_list);
175 up_write(&triggers_list_lock);
176
177 /* Register with any LEDs that have this as a default trigger */
178 down_read(&leds_list_lock);
179 list_for_each_entry(led_cdev, &leds_list, node) {
180 down_write(&led_cdev->trigger_lock);
181 if (!led_cdev->trigger && led_cdev->default_trigger &&
182 !strcmp(led_cdev->default_trigger, trigger->name))
183 led_trigger_set(led_cdev, trigger);
184 up_write(&led_cdev->trigger_lock);
185 }
186 up_read(&leds_list_lock);
187
188 return 0;
189}
190EXPORT_SYMBOL_GPL(led_trigger_register);
191
192void led_trigger_unregister(struct led_trigger *trigger)
193{
194 struct led_classdev *led_cdev;
195
196 /* Remove from the list of led triggers */
197 down_write(&triggers_list_lock);
198 list_del(&trigger->next_trig);
199 up_write(&triggers_list_lock);
200
201 /* Remove anyone actively using this trigger */
202 down_read(&leds_list_lock);
203 list_for_each_entry(led_cdev, &leds_list, node) {
204 down_write(&led_cdev->trigger_lock);
205 if (led_cdev->trigger == trigger)
206 led_trigger_set(led_cdev, NULL);
207 up_write(&led_cdev->trigger_lock);
208 }
209 up_read(&leds_list_lock);
210}
211EXPORT_SYMBOL_GPL(led_trigger_unregister);
212
213/* Simple LED Tigger Interface */
214
215void led_trigger_event(struct led_trigger *trigger,
216 enum led_brightness brightness)
217{
218 struct list_head *entry;
219
220 if (!trigger)
221 return;
222
223 read_lock(&trigger->leddev_list_lock);
224 list_for_each(entry, &trigger->led_cdevs) {
225 struct led_classdev *led_cdev;
226
227 led_cdev = list_entry(entry, struct led_classdev, trig_list);
228 led_set_brightness(led_cdev, brightness);
229 }
230 read_unlock(&trigger->leddev_list_lock);
231}
232EXPORT_SYMBOL_GPL(led_trigger_event);
233
234void led_trigger_blink(struct led_trigger *trigger,
235 unsigned long *delay_on,
236 unsigned long *delay_off)
237{
238 struct list_head *entry;
239
240 if (!trigger)
241 return;
242
243 read_lock(&trigger->leddev_list_lock);
244 list_for_each(entry, &trigger->led_cdevs) {
245 struct led_classdev *led_cdev;
246
247 led_cdev = list_entry(entry, struct led_classdev, trig_list);
248 led_blink_set(led_cdev, delay_on, delay_off);
249 }
250 read_unlock(&trigger->leddev_list_lock);
251}
252EXPORT_SYMBOL_GPL(led_trigger_blink);
253
254void led_trigger_register_simple(const char *name, struct led_trigger **tp)
255{
256 struct led_trigger *trigger;
257 int err;
258
259 trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
260
261 if (trigger) {
262 trigger->name = name;
263 err = led_trigger_register(trigger);
264 if (err < 0)
265 printk(KERN_WARNING "LED trigger %s failed to register"
266 " (%d)\n", name, err);
267 } else
268 printk(KERN_WARNING "LED trigger %s failed to register"
269 " (no memory)\n", name);
270
271 *tp = trigger;
272}
273EXPORT_SYMBOL_GPL(led_trigger_register_simple);
274
275void led_trigger_unregister_simple(struct led_trigger *trigger)
276{
277 if (trigger)
278 led_trigger_unregister(trigger);
279 kfree(trigger);
280}
281EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
282
283MODULE_AUTHOR("Richard Purdie");
284MODULE_LICENSE("GPL");
285MODULE_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 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");