1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * LED state routines for driver control interface
4 * Copyright (c) 2021 by Jaroslav Kysela <perex@perex.cz>
5 */
6
7 #include <linux/slab.h>
8 #include <linux/module.h>
9 #include <linux/leds.h>
10 #include <sound/core.h>
11 #include <sound/control.h>
12
13 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
14 MODULE_DESCRIPTION("ALSA control interface to LED trigger code.");
15 MODULE_LICENSE("GPL");
16
17 #define MAX_LED (((SNDRV_CTL_ELEM_ACCESS_MIC_LED - SNDRV_CTL_ELEM_ACCESS_SPK_LED) \
18 >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) + 1)
19
20 #define to_led_card_dev(_dev) \
21 container_of(_dev, struct snd_ctl_led_card, dev)
22
23 enum snd_ctl_led_mode {
24 MODE_FOLLOW_MUTE = 0,
25 MODE_FOLLOW_ROUTE,
26 MODE_OFF,
27 MODE_ON,
28 };
29
30 struct snd_ctl_led_card {
31 struct device dev;
32 int number;
33 struct snd_ctl_led *led;
34 };
35
36 struct snd_ctl_led {
37 struct device dev;
38 struct list_head controls;
39 const char *name;
40 unsigned int group;
41 enum led_audio trigger_type;
42 enum snd_ctl_led_mode mode;
43 struct snd_ctl_led_card *cards[SNDRV_CARDS];
44 };
45
46 struct snd_ctl_led_ctl {
47 struct list_head list;
48 struct snd_card *card;
49 unsigned int access;
50 struct snd_kcontrol *kctl;
51 unsigned int index_offset;
52 };
53
54 static DEFINE_MUTEX(snd_ctl_led_mutex);
55 static bool snd_ctl_led_card_valid[SNDRV_CARDS];
56 static struct led_trigger *snd_ctl_ledtrig_audio[NUM_AUDIO_LEDS];
57 static struct snd_ctl_led snd_ctl_leds[MAX_LED] = {
58 {
59 .name = "speaker",
60 .group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
61 .trigger_type = LED_AUDIO_MUTE,
62 .mode = MODE_FOLLOW_MUTE,
63 },
64 {
65 .name = "mic",
66 .group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
67 .trigger_type = LED_AUDIO_MICMUTE,
68 .mode = MODE_FOLLOW_MUTE,
69 },
70 };
71
72 static void snd_ctl_led_sysfs_add(struct snd_card *card);
73 static void snd_ctl_led_sysfs_remove(struct snd_card *card);
74
75 #define UPDATE_ROUTE(route, cb) \
76 do { \
77 int route2 = (cb); \
78 if (route2 >= 0) \
79 route = route < 0 ? route2 : (route | route2); \
80 } while (0)
81
82 static inline unsigned int access_to_group(unsigned int access)
83 {
84 return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >>
85 SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1;
86 }
87
88 static inline unsigned int group_to_access(unsigned int group)
89 {
90 return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
91 }
92
93 static struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
94 {
95 unsigned int group = access_to_group(access);
96 if (group >= MAX_LED)
97 return NULL;
98 return &snd_ctl_leds[group];
99 }
100
101 /*
102 * A note for callers:
103 * The two static variables info and value are protected using snd_ctl_led_mutex.
104 */
105 static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
106 {
107 static struct snd_ctl_elem_info info;
108 static struct snd_ctl_elem_value value;
109 struct snd_kcontrol *kctl = lctl->kctl;
110 unsigned int i;
111 int result;
112
113 memset(&info, 0, sizeof(info));
114 info.id = kctl->id;
115 info.id.index += lctl->index_offset;
116 info.id.numid += lctl->index_offset;
117 result = kctl->info(kctl, &info);
118 if (result < 0)
119 return -1;
120 memset(&value, 0, sizeof(value));
121 value.id = info.id;
122 result = kctl->get(kctl, &value);
123 if (result < 0)
124 return -1;
125 if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
126 info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
127 for (i = 0; i < info.count; i++)
128 if (value.value.integer.value[i] != info.value.integer.min)
129 return 1;
130 } else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) {
131 for (i = 0; i < info.count; i++)
132 if (value.value.integer64.value[i] != info.value.integer64.min)
133 return 1;
134 }
135 return 0;
136 }
137
138 static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
139 struct snd_kcontrol *kctl, unsigned int ioff)
140 {
141 struct snd_ctl_led *led;
142 struct snd_ctl_led_ctl *lctl;
143 int route;
144 bool found;
145
146 led = snd_ctl_led_get_by_access(access);
147 if (!led)
148 return;
149 route = -1;
150 found = false;
151 scoped_guard(mutex, &snd_ctl_led_mutex) {
152 /* the card may not be registered (active) at this point */
153 if (card && !snd_ctl_led_card_valid[card->number])
154 return;
155 list_for_each_entry(lctl, &led->controls, list) {
156 if (lctl->kctl == kctl && lctl->index_offset == ioff)
157 found = true;
158 UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
159 }
160 if (!found && kctl && card) {
161 lctl = kzalloc(sizeof(*lctl), GFP_KERNEL);
162 if (lctl) {
163 lctl->card = card;
164 lctl->access = access;
165 lctl->kctl = kctl;
166 lctl->index_offset = ioff;
167 list_add(&lctl->list, &led->controls);
168 UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
169 }
170 }
171 }
172 switch (led->mode) {
173 case MODE_OFF: route = 1; break;
174 case MODE_ON: route = 0; break;
175 case MODE_FOLLOW_ROUTE: if (route >= 0) route ^= 1; break;
176 case MODE_FOLLOW_MUTE: /* noop */ break;
177 }
178 if (route >= 0) {
179 struct led_trigger *trig = snd_ctl_ledtrig_audio[led->trigger_type];
180
181 led_trigger_event(trig, route ? LED_OFF : LED_ON);
182 }
183 }
184
185 static struct snd_ctl_led_ctl *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
186 {
187 struct list_head *controls;
188 struct snd_ctl_led_ctl *lctl;
189 unsigned int group;
190
191 for (group = 0; group < MAX_LED; group++) {
192 controls = &snd_ctl_leds[group].controls;
193 list_for_each_entry(lctl, controls, list)
194 if (lctl->kctl == kctl && lctl->index_offset == ioff)
195 return lctl;
196 }
197 return NULL;
198 }
199
200 static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff,
201 unsigned int access)
202 {
203 struct snd_ctl_led_ctl *lctl;
204 unsigned int ret = 0;
205
206 guard(mutex)(&snd_ctl_led_mutex);
207 lctl = snd_ctl_led_find(kctl, ioff);
208 if (lctl && (access == 0 || access != lctl->access)) {
209 ret = lctl->access;
210 list_del(&lctl->list);
211 kfree(lctl);
212 }
213 return ret;
214 }
215
216 static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask,
217 struct snd_kcontrol *kctl, unsigned int ioff)
218 {
219 struct snd_kcontrol_volatile *vd;
220 unsigned int access, access2;
221
222 if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) {
223 access = snd_ctl_led_remove(kctl, ioff, 0);
224 if (access)
225 snd_ctl_led_set_state(card, access, NULL, 0);
226 } else if (mask & SNDRV_CTL_EVENT_MASK_INFO) {
227 vd = &kctl->vd[ioff];
228 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
229 access2 = snd_ctl_led_remove(kctl, ioff, access);
230 if (access2)
231 snd_ctl_led_set_state(card, access2, NULL, 0);
232 if (access)
233 snd_ctl_led_set_state(card, access, kctl, ioff);
234 } else if ((mask & (SNDRV_CTL_EVENT_MASK_ADD |
235 SNDRV_CTL_EVENT_MASK_VALUE)) != 0) {
236 vd = &kctl->vd[ioff];
237 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
238 if (access)
239 snd_ctl_led_set_state(card, access, kctl, ioff);
240 }
241 }
242
243 DEFINE_FREE(snd_card_unref, struct snd_card *, if (_T) snd_card_unref(_T))
244
245 static int snd_ctl_led_set_id(int card_number, struct snd_ctl_elem_id *id,
246 unsigned int group, bool set)
247 {
248 struct snd_card *card __free(snd_card_unref) = NULL;
249 struct snd_kcontrol *kctl;
250 struct snd_kcontrol_volatile *vd;
251 unsigned int ioff, access, new_access;
252
253 card = snd_card_ref(card_number);
254 if (!card)
255 return -ENXIO;
256 guard(rwsem_write)(&card->controls_rwsem);
257 kctl = snd_ctl_find_id_locked(card, id);
258 if (!kctl)
259 return -ENOENT;
260 ioff = snd_ctl_get_ioff(kctl, id);
261 vd = &kctl->vd[ioff];
262 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
263 if (access != 0 && access != group_to_access(group))
264 return -EXDEV;
265 new_access = vd->access & ~SNDRV_CTL_ELEM_ACCESS_LED_MASK;
266 if (set)
267 new_access |= group_to_access(group);
268 if (new_access != vd->access) {
269 vd->access = new_access;
270 snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, ioff);
271 }
272 return 0;
273 }
274
275 static void snd_ctl_led_refresh(void)
276 {
277 unsigned int group;
278
279 for (group = 0; group < MAX_LED; group++)
280 snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
281 }
282
283 static void snd_ctl_led_ctl_destroy(struct snd_ctl_led_ctl *lctl)
284 {
285 list_del(&lctl->list);
286 kfree(lctl);
287 }
288
289 static void snd_ctl_led_clean(struct snd_card *card)
290 {
291 unsigned int group;
292 struct snd_ctl_led_ctl *lctl, *_lctl;
293 struct snd_ctl_led *led;
294
295 for (group = 0; group < MAX_LED; group++) {
296 led = &snd_ctl_leds[group];
297 list_for_each_entry_safe(lctl, _lctl, &led->controls, list)
298 if (!card || lctl->card == card)
299 snd_ctl_led_ctl_destroy(lctl);
300 }
301 }
302
303 static int snd_ctl_led_reset(int card_number, unsigned int group)
304 {
305 struct snd_card *card __free(snd_card_unref) = NULL;
306 struct snd_ctl_led_ctl *lctl, *_lctl;
307 struct snd_ctl_led *led;
308 struct snd_kcontrol_volatile *vd;
309 bool change = false;
310
311 card = snd_card_ref(card_number);
312 if (!card)
313 return -ENXIO;
314
315 scoped_guard(mutex, &snd_ctl_led_mutex) {
316 if (!snd_ctl_led_card_valid[card_number])
317 return -ENXIO;
318 led = &snd_ctl_leds[group];
319 list_for_each_entry_safe(lctl, _lctl, &led->controls, list)
320 if (lctl->card == card) {
321 vd = &lctl->kctl->vd[lctl->index_offset];
322 vd->access &= ~group_to_access(group);
323 snd_ctl_led_ctl_destroy(lctl);
324 change = true;
325 }
326 }
327 if (change)
328 snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
329 return 0;
330 }
331
332 static void snd_ctl_led_register(struct snd_card *card)
333 {
334 struct snd_kcontrol *kctl;
335 unsigned int ioff;
336
337 if (snd_BUG_ON(card->number < 0 ||
338 card->number >= ARRAY_SIZE(snd_ctl_led_card_valid)))
339 return;
340 scoped_guard(mutex, &snd_ctl_led_mutex)
341 snd_ctl_led_card_valid[card->number] = true;
342 /* the register callback is already called with held card->controls_rwsem */
343 list_for_each_entry(kctl, &card->controls, list)
344 for (ioff = 0; ioff < kctl->count; ioff++)
345 snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
346 snd_ctl_led_refresh();
347 snd_ctl_led_sysfs_add(card);
348 }
349
350 static void snd_ctl_led_disconnect(struct snd_card *card)
351 {
352 snd_ctl_led_sysfs_remove(card);
353 scoped_guard(mutex, &snd_ctl_led_mutex) {
354 snd_ctl_led_card_valid[card->number] = false;
355 snd_ctl_led_clean(card);
356 }
357 snd_ctl_led_refresh();
358 }
359
360 static void snd_ctl_led_card_release(struct device *dev)
361 {
362 struct snd_ctl_led_card *led_card = to_led_card_dev(dev);
363
364 kfree(led_card);
365 }
366
367 static void snd_ctl_led_release(struct device *dev)
368 {
369 }
370
371 static void snd_ctl_led_dev_release(struct device *dev)
372 {
373 }
374
375 /*
376 * sysfs
377 */
378
379 static ssize_t mode_show(struct device *dev,
380 struct device_attribute *attr, char *buf)
381 {
382 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
383 const char *str = NULL;
384
385 switch (led->mode) {
386 case MODE_FOLLOW_MUTE: str = "follow-mute"; break;
387 case MODE_FOLLOW_ROUTE: str = "follow-route"; break;
388 case MODE_ON: str = "on"; break;
389 case MODE_OFF: str = "off"; break;
390 }
391 return sysfs_emit(buf, "%s\n", str);
392 }
393
394 static ssize_t mode_store(struct device *dev,
395 struct device_attribute *attr,
396 const char *buf, size_t count)
397 {
398 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
399 char _buf[16];
400 size_t l = min(count, sizeof(_buf) - 1);
401 enum snd_ctl_led_mode mode;
402
403 memcpy(_buf, buf, l);
404 _buf[l] = '\0';
405 if (strstr(_buf, "mute"))
406 mode = MODE_FOLLOW_MUTE;
407 else if (strstr(_buf, "route"))
408 mode = MODE_FOLLOW_ROUTE;
409 else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "", 1) == 0)
410 mode = MODE_OFF;
411 else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
412 mode = MODE_ON;
413 else
414 return count;
415
416 scoped_guard(mutex, &snd_ctl_led_mutex)
417 led->mode = mode;
418
419 snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
420 return count;
421 }
422
423 static ssize_t brightness_show(struct device *dev,
424 struct device_attribute *attr, char *buf)
425 {
426 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
427 struct led_trigger *trig = snd_ctl_ledtrig_audio[led->trigger_type];
428
429 return sysfs_emit(buf, "%u\n", led_trigger_get_brightness(trig));
430 }
431
432 static DEVICE_ATTR_RW(mode);
433 static DEVICE_ATTR_RO(brightness);
434
435 static struct attribute *snd_ctl_led_dev_attrs[] = {
436 &dev_attr_mode.attr,
437 &dev_attr_brightness.attr,
438 NULL,
439 };
440
441 static const struct attribute_group snd_ctl_led_dev_attr_group = {
442 .attrs = snd_ctl_led_dev_attrs,
443 };
444
445 static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
446 &snd_ctl_led_dev_attr_group,
447 NULL,
448 };
449
450 static char *find_eos(char *s)
451 {
452 while (*s && *s != ',')
453 s++;
454 if (*s)
455 s++;
456 return s;
457 }
458
459 static char *parse_uint(char *s, unsigned int *val)
460 {
461 unsigned long long res;
462 if (kstrtoull(s, 10, &res))
463 res = 0;
464 *val = res;
465 return find_eos(s);
466 }
467
468 static char *parse_string(char *s, char *val, size_t val_size)
469 {
470 if (*s == '"' || *s == '\'') {
471 char c = *s;
472 s++;
473 while (*s && *s != c) {
474 if (val_size > 1) {
475 *val++ = *s;
476 val_size--;
477 }
478 s++;
479 }
480 } else {
481 while (*s && *s != ',') {
482 if (val_size > 1) {
483 *val++ = *s;
484 val_size--;
485 }
486 s++;
487 }
488 }
489 *val = '\0';
490 if (*s)
491 s++;
492 return s;
493 }
494
495 static char *parse_iface(char *s, snd_ctl_elem_iface_t *val)
496 {
497 if (!strncasecmp(s, "card", 4))
498 *val = SNDRV_CTL_ELEM_IFACE_CARD;
499 else if (!strncasecmp(s, "mixer", 5))
500 *val = SNDRV_CTL_ELEM_IFACE_MIXER;
501 return find_eos(s);
502 }
503
504 /*
505 * These types of input strings are accepted:
506 *
507 * unsigned integer - numid (equivaled to numid=UINT)
508 * string - basic mixer name (equivalent to iface=MIXER,name=STR)
509 * numid=UINT
510 * [iface=MIXER,][device=UINT,][subdevice=UINT,]name=STR[,index=UINT]
511 */
512 static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, size_t count,
513 bool attach)
514 {
515 char buf2[256], *s, *os;
516 struct snd_ctl_elem_id id;
517 int err;
518
519 if (strscpy(buf2, buf, sizeof(buf2)) < 0)
520 return -E2BIG;
521 memset(&id, 0, sizeof(id));
522 id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
523 s = buf2;
524 while (*s) {
525 os = s;
526 if (!strncasecmp(s, "numid=", 6)) {
527 s = parse_uint(s + 6, &id.numid);
528 } else if (!strncasecmp(s, "iface=", 6)) {
529 s = parse_iface(s + 6, &id.iface);
530 } else if (!strncasecmp(s, "device=", 7)) {
531 s = parse_uint(s + 7, &id.device);
532 } else if (!strncasecmp(s, "subdevice=", 10)) {
533 s = parse_uint(s + 10, &id.subdevice);
534 } else if (!strncasecmp(s, "name=", 5)) {
535 s = parse_string(s + 5, id.name, sizeof(id.name));
536 } else if (!strncasecmp(s, "index=", 6)) {
537 s = parse_uint(s + 6, &id.index);
538 } else if (s == buf2) {
539 while (*s) {
540 if (*s < '' || *s > '9')
541 break;
542 s++;
543 }
544 if (*s == '\0')
545 parse_uint(buf2, &id.numid);
546 else {
547 for (; *s >= ' '; s++);
548 *s = '\0';
549 strscpy(id.name, buf2, sizeof(id.name));
550 }
551 break;
552 }
553 if (*s == ',')
554 s++;
555 if (s == os)
556 break;
557 }
558
559 err = snd_ctl_led_set_id(led_card->number, &id, led_card->led->group, attach);
560 if (err < 0)
561 return err;
562
563 return count;
564 }
565
566 static ssize_t attach_store(struct device *dev,
567 struct device_attribute *attr,
568 const char *buf, size_t count)
569 {
570 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
571 return set_led_id(led_card, buf, count, true);
572 }
573
574 static ssize_t detach_store(struct device *dev,
575 struct device_attribute *attr,
576 const char *buf, size_t count)
577 {
578 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
579 return set_led_id(led_card, buf, count, false);
580 }
581
582 static ssize_t reset_store(struct device *dev,
583 struct device_attribute *attr,
584 const char *buf, size_t count)
585 {
586 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
587 int err;
588
589 if (count > 0 && buf[0] == '1') {
590 err = snd_ctl_led_reset(led_card->number, led_card->led->group);
591 if (err < 0)
592 return err;
593 }
594 return count;
595 }
596
597 static ssize_t list_show(struct device *dev,
598 struct device_attribute *attr, char *buf)
599 {
600 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
601 struct snd_card *card __free(snd_card_unref) = NULL;
602 struct snd_ctl_led_ctl *lctl;
603 size_t l = 0;
604
605 card = snd_card_ref(led_card->number);
606 if (!card)
607 return -ENXIO;
608 guard(rwsem_read)(&card->controls_rwsem);
609 guard(mutex)(&snd_ctl_led_mutex);
610 if (snd_ctl_led_card_valid[led_card->number]) {
611 list_for_each_entry(lctl, &led_card->led->controls, list) {
612 if (lctl->card != card)
613 continue;
614 if (l)
615 l += sysfs_emit_at(buf, l, " ");
616 l += sysfs_emit_at(buf, l, "%u",
617 lctl->kctl->id.numid + lctl->index_offset);
618 }
619 }
620 return l;
621 }
622
623 static DEVICE_ATTR_WO(attach);
624 static DEVICE_ATTR_WO(detach);
625 static DEVICE_ATTR_WO(reset);
626 static DEVICE_ATTR_RO(list);
627
628 static struct attribute *snd_ctl_led_card_attrs[] = {
629 &dev_attr_attach.attr,
630 &dev_attr_detach.attr,
631 &dev_attr_reset.attr,
632 &dev_attr_list.attr,
633 NULL,
634 };
635
636 static const struct attribute_group snd_ctl_led_card_attr_group = {
637 .attrs = snd_ctl_led_card_attrs,
638 };
639
640 static const struct attribute_group *snd_ctl_led_card_attr_groups[] = {
641 &snd_ctl_led_card_attr_group,
642 NULL,
643 };
644
645 static struct device snd_ctl_led_dev;
646
647 static void snd_ctl_led_sysfs_add(struct snd_card *card)
648 {
649 unsigned int group;
650 struct snd_ctl_led_card *led_card;
651 struct snd_ctl_led *led;
652 char link_name[32];
653
654 for (group = 0; group < MAX_LED; group++) {
655 led = &snd_ctl_leds[group];
656 led_card = kzalloc(sizeof(*led_card), GFP_KERNEL);
657 if (!led_card)
658 goto cerr2;
659 led_card->number = card->number;
660 led_card->led = led;
661 device_initialize(&led_card->dev);
662 led_card->dev.release = snd_ctl_led_card_release;
663 if (dev_set_name(&led_card->dev, "card%d", card->number) < 0)
664 goto cerr;
665 led_card->dev.parent = &led->dev;
666 led_card->dev.groups = snd_ctl_led_card_attr_groups;
667 if (device_add(&led_card->dev))
668 goto cerr;
669 led->cards[card->number] = led_card;
670 snprintf(link_name, sizeof(link_name), "led-%s", led->name);
671 WARN(sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj, link_name),
672 "can't create symlink to controlC%i device\n", card->number);
673 WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"),
674 "can't create symlink to card%i\n", card->number);
675
676 continue;
677 cerr:
678 put_device(&led_card->dev);
679 cerr2:
680 printk(KERN_ERR "snd_ctl_led: unable to add card%d", card->number);
681 }
682 }
683
684 static void snd_ctl_led_sysfs_remove(struct snd_card *card)
685 {
686 unsigned int group;
687 struct snd_ctl_led_card *led_card;
688 struct snd_ctl_led *led;
689 char link_name[32];
690
691 for (group = 0; group < MAX_LED; group++) {
692 led = &snd_ctl_leds[group];
693 led_card = led->cards[card->number];
694 if (!led_card)
695 continue;
696 snprintf(link_name, sizeof(link_name), "led-%s", led->name);
697 sysfs_remove_link(&card->ctl_dev->kobj, link_name);
698 sysfs_remove_link(&led_card->dev.kobj, "card");
699 device_unregister(&led_card->dev);
700 led->cards[card->number] = NULL;
701 }
702 }
703
704 /*
705 * Control layer registration
706 */
707 static struct snd_ctl_layer_ops snd_ctl_led_lops = {
708 .module_name = SND_CTL_LAYER_MODULE_LED,
709 .lregister = snd_ctl_led_register,
710 .ldisconnect = snd_ctl_led_disconnect,
711 .lnotify = snd_ctl_led_notify,
712 };
713
714 static int __init snd_ctl_led_init(void)
715 {
716 struct snd_ctl_led *led;
717 unsigned int group;
718
719 led_trigger_register_simple("audio-mute", &snd_ctl_ledtrig_audio[LED_AUDIO_MUTE]);
720 led_trigger_register_simple("audio-micmute", &snd_ctl_ledtrig_audio[LED_AUDIO_MICMUTE]);
721
722 device_initialize(&snd_ctl_led_dev);
723 snd_ctl_led_dev.class = &sound_class;
724 snd_ctl_led_dev.release = snd_ctl_led_dev_release;
725 dev_set_name(&snd_ctl_led_dev, "ctl-led");
726 if (device_add(&snd_ctl_led_dev)) {
727 put_device(&snd_ctl_led_dev);
728 return -ENOMEM;
729 }
730 for (group = 0; group < MAX_LED; group++) {
731 led = &snd_ctl_leds[group];
732 INIT_LIST_HEAD(&led->controls);
733 device_initialize(&led->dev);
734 led->dev.parent = &snd_ctl_led_dev;
735 led->dev.release = snd_ctl_led_release;
736 led->dev.groups = snd_ctl_led_dev_attr_groups;
737 dev_set_name(&led->dev, led->name);
738 if (device_add(&led->dev)) {
739 put_device(&led->dev);
740 for (; group > 0; group--) {
741 led = &snd_ctl_leds[group - 1];
742 device_unregister(&led->dev);
743 }
744 device_unregister(&snd_ctl_led_dev);
745 return -ENOMEM;
746 }
747 }
748 snd_ctl_register_layer(&snd_ctl_led_lops);
749 return 0;
750 }
751
752 static void __exit snd_ctl_led_exit(void)
753 {
754 struct snd_ctl_led *led;
755 struct snd_card *card;
756 unsigned int group, card_number;
757
758 snd_ctl_disconnect_layer(&snd_ctl_led_lops);
759 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
760 if (!snd_ctl_led_card_valid[card_number])
761 continue;
762 card = snd_card_ref(card_number);
763 if (card) {
764 snd_ctl_led_sysfs_remove(card);
765 snd_card_unref(card);
766 }
767 }
768 for (group = 0; group < MAX_LED; group++) {
769 led = &snd_ctl_leds[group];
770 device_unregister(&led->dev);
771 }
772 device_unregister(&snd_ctl_led_dev);
773 snd_ctl_led_clean(NULL);
774
775 led_trigger_unregister_simple(snd_ctl_ledtrig_audio[LED_AUDIO_MUTE]);
776 led_trigger_unregister_simple(snd_ctl_ledtrig_audio[LED_AUDIO_MICMUTE]);
777 }
778
779 module_init(snd_ctl_led_init)
780 module_exit(snd_ctl_led_exit)
781
782 MODULE_ALIAS("ledtrig:audio-mute");
783 MODULE_ALIAS("ledtrig:audio-micmute");
784
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.