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 snd_ctl_led snd_ctl_leds[MAX_LED] = {
57 {
58 .name = "speaker",
59 .group = (SNDRV_CTL_ELEM_ACCESS_SPK_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
60 .trigger_type = LED_AUDIO_MUTE,
61 .mode = MODE_FOLLOW_MUTE,
62 },
63 {
64 .name = "mic",
65 .group = (SNDRV_CTL_ELEM_ACCESS_MIC_LED >> SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1,
66 .trigger_type = LED_AUDIO_MICMUTE,
67 .mode = MODE_FOLLOW_MUTE,
68 },
69 };
70
71 static void snd_ctl_led_sysfs_add(struct snd_card *card);
72 static void snd_ctl_led_sysfs_remove(struct snd_card *card);
73
74 #define UPDATE_ROUTE(route, cb) \
75 do { \
76 int route2 = (cb); \
77 if (route2 >= 0) \
78 route = route < 0 ? route2 : (route | route2); \
79 } while (0)
80
access_to_group(unsigned int access)81 static inline unsigned int access_to_group(unsigned int access)
82 {
83 return ((access & SNDRV_CTL_ELEM_ACCESS_LED_MASK) >>
84 SNDRV_CTL_ELEM_ACCESS_LED_SHIFT) - 1;
85 }
86
group_to_access(unsigned int group)87 static inline unsigned int group_to_access(unsigned int group)
88 {
89 return (group + 1) << SNDRV_CTL_ELEM_ACCESS_LED_SHIFT;
90 }
91
snd_ctl_led_get_by_access(unsigned int access)92 static struct snd_ctl_led *snd_ctl_led_get_by_access(unsigned int access)
93 {
94 unsigned int group = access_to_group(access);
95 if (group >= MAX_LED)
96 return NULL;
97 return &snd_ctl_leds[group];
98 }
99
100 /*
101 * A note for callers:
102 * The two static variables info and value are protected using snd_ctl_led_mutex.
103 */
snd_ctl_led_get(struct snd_ctl_led_ctl * lctl)104 static int snd_ctl_led_get(struct snd_ctl_led_ctl *lctl)
105 {
106 static struct snd_ctl_elem_info info;
107 static struct snd_ctl_elem_value value;
108 struct snd_kcontrol *kctl = lctl->kctl;
109 unsigned int i;
110 int result;
111
112 memset(&info, 0, sizeof(info));
113 info.id = kctl->id;
114 info.id.index += lctl->index_offset;
115 info.id.numid += lctl->index_offset;
116 result = kctl->info(kctl, &info);
117 if (result < 0)
118 return -1;
119 memset(&value, 0, sizeof(value));
120 value.id = info.id;
121 result = kctl->get(kctl, &value);
122 if (result < 0)
123 return -1;
124 if (info.type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
125 info.type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
126 for (i = 0; i < info.count; i++)
127 if (value.value.integer.value[i] != info.value.integer.min)
128 return 1;
129 } else if (info.type == SNDRV_CTL_ELEM_TYPE_INTEGER64) {
130 for (i = 0; i < info.count; i++)
131 if (value.value.integer64.value[i] != info.value.integer64.min)
132 return 1;
133 }
134 return 0;
135 }
136
snd_ctl_led_set_state(struct snd_card * card,unsigned int access,struct snd_kcontrol * kctl,unsigned int ioff)137 static void snd_ctl_led_set_state(struct snd_card *card, unsigned int access,
138 struct snd_kcontrol *kctl, unsigned int ioff)
139 {
140 struct snd_ctl_led *led;
141 struct snd_ctl_led_ctl *lctl;
142 int route;
143 bool found;
144
145 led = snd_ctl_led_get_by_access(access);
146 if (!led)
147 return;
148 route = -1;
149 found = false;
150 mutex_lock(&snd_ctl_led_mutex);
151 /* the card may not be registered (active) at this point */
152 if (card && !snd_ctl_led_card_valid[card->number]) {
153 mutex_unlock(&snd_ctl_led_mutex);
154 return;
155 }
156 list_for_each_entry(lctl, &led->controls, list) {
157 if (lctl->kctl == kctl && lctl->index_offset == ioff)
158 found = true;
159 UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
160 }
161 if (!found && kctl && card) {
162 lctl = kzalloc(sizeof(*lctl), GFP_KERNEL);
163 if (lctl) {
164 lctl->card = card;
165 lctl->access = access;
166 lctl->kctl = kctl;
167 lctl->index_offset = ioff;
168 list_add(&lctl->list, &led->controls);
169 UPDATE_ROUTE(route, snd_ctl_led_get(lctl));
170 }
171 }
172 mutex_unlock(&snd_ctl_led_mutex);
173 switch (led->mode) {
174 case MODE_OFF: route = 1; break;
175 case MODE_ON: route = 0; break;
176 case MODE_FOLLOW_ROUTE: if (route >= 0) route ^= 1; break;
177 case MODE_FOLLOW_MUTE: /* noop */ break;
178 }
179 if (route >= 0)
180 ledtrig_audio_set(led->trigger_type, route ? LED_OFF : LED_ON);
181 }
182
snd_ctl_led_find(struct snd_kcontrol * kctl,unsigned int ioff)183 static struct snd_ctl_led_ctl *snd_ctl_led_find(struct snd_kcontrol *kctl, unsigned int ioff)
184 {
185 struct list_head *controls;
186 struct snd_ctl_led_ctl *lctl;
187 unsigned int group;
188
189 for (group = 0; group < MAX_LED; group++) {
190 controls = &snd_ctl_leds[group].controls;
191 list_for_each_entry(lctl, controls, list)
192 if (lctl->kctl == kctl && lctl->index_offset == ioff)
193 return lctl;
194 }
195 return NULL;
196 }
197
snd_ctl_led_remove(struct snd_kcontrol * kctl,unsigned int ioff,unsigned int access)198 static unsigned int snd_ctl_led_remove(struct snd_kcontrol *kctl, unsigned int ioff,
199 unsigned int access)
200 {
201 struct snd_ctl_led_ctl *lctl;
202 unsigned int ret = 0;
203
204 mutex_lock(&snd_ctl_led_mutex);
205 lctl = snd_ctl_led_find(kctl, ioff);
206 if (lctl && (access == 0 || access != lctl->access)) {
207 ret = lctl->access;
208 list_del(&lctl->list);
209 kfree(lctl);
210 }
211 mutex_unlock(&snd_ctl_led_mutex);
212 return ret;
213 }
214
snd_ctl_led_notify(struct snd_card * card,unsigned int mask,struct snd_kcontrol * kctl,unsigned int ioff)215 static void snd_ctl_led_notify(struct snd_card *card, unsigned int mask,
216 struct snd_kcontrol *kctl, unsigned int ioff)
217 {
218 struct snd_kcontrol_volatile *vd;
219 unsigned int access, access2;
220
221 if (mask == SNDRV_CTL_EVENT_MASK_REMOVE) {
222 access = snd_ctl_led_remove(kctl, ioff, 0);
223 if (access)
224 snd_ctl_led_set_state(card, access, NULL, 0);
225 } else if (mask & SNDRV_CTL_EVENT_MASK_INFO) {
226 vd = &kctl->vd[ioff];
227 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
228 access2 = snd_ctl_led_remove(kctl, ioff, access);
229 if (access2)
230 snd_ctl_led_set_state(card, access2, NULL, 0);
231 if (access)
232 snd_ctl_led_set_state(card, access, kctl, ioff);
233 } else if ((mask & (SNDRV_CTL_EVENT_MASK_ADD |
234 SNDRV_CTL_EVENT_MASK_VALUE)) != 0) {
235 vd = &kctl->vd[ioff];
236 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
237 if (access)
238 snd_ctl_led_set_state(card, access, kctl, ioff);
239 }
240 }
241
snd_ctl_led_set_id(int card_number,struct snd_ctl_elem_id * id,unsigned int group,bool set)242 static int snd_ctl_led_set_id(int card_number, struct snd_ctl_elem_id *id,
243 unsigned int group, bool set)
244 {
245 struct snd_card *card;
246 struct snd_kcontrol *kctl;
247 struct snd_kcontrol_volatile *vd;
248 unsigned int ioff, access, new_access;
249 int err = 0;
250
251 card = snd_card_ref(card_number);
252 if (card) {
253 down_write(&card->controls_rwsem);
254 kctl = snd_ctl_find_id_locked(card, id);
255 if (kctl) {
256 ioff = snd_ctl_get_ioff(kctl, id);
257 vd = &kctl->vd[ioff];
258 access = vd->access & SNDRV_CTL_ELEM_ACCESS_LED_MASK;
259 if (access != 0 && access != group_to_access(group)) {
260 err = -EXDEV;
261 goto unlock;
262 }
263 new_access = vd->access & ~SNDRV_CTL_ELEM_ACCESS_LED_MASK;
264 if (set)
265 new_access |= group_to_access(group);
266 if (new_access != vd->access) {
267 vd->access = new_access;
268 snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, ioff);
269 }
270 } else {
271 err = -ENOENT;
272 }
273 unlock:
274 up_write(&card->controls_rwsem);
275 snd_card_unref(card);
276 } else {
277 err = -ENXIO;
278 }
279 return err;
280 }
281
snd_ctl_led_refresh(void)282 static void snd_ctl_led_refresh(void)
283 {
284 unsigned int group;
285
286 for (group = 0; group < MAX_LED; group++)
287 snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
288 }
289
snd_ctl_led_ctl_destroy(struct snd_ctl_led_ctl * lctl)290 static void snd_ctl_led_ctl_destroy(struct snd_ctl_led_ctl *lctl)
291 {
292 list_del(&lctl->list);
293 kfree(lctl);
294 }
295
snd_ctl_led_clean(struct snd_card * card)296 static void snd_ctl_led_clean(struct snd_card *card)
297 {
298 unsigned int group;
299 struct snd_ctl_led *led;
300 struct snd_ctl_led_ctl *lctl;
301
302 for (group = 0; group < MAX_LED; group++) {
303 led = &snd_ctl_leds[group];
304 repeat:
305 list_for_each_entry(lctl, &led->controls, list)
306 if (!card || lctl->card == card) {
307 snd_ctl_led_ctl_destroy(lctl);
308 goto repeat;
309 }
310 }
311 }
312
snd_ctl_led_reset(int card_number,unsigned int group)313 static int snd_ctl_led_reset(int card_number, unsigned int group)
314 {
315 struct snd_card *card;
316 struct snd_ctl_led *led;
317 struct snd_ctl_led_ctl *lctl;
318 struct snd_kcontrol_volatile *vd;
319 bool change = false;
320
321 card = snd_card_ref(card_number);
322 if (!card)
323 return -ENXIO;
324
325 mutex_lock(&snd_ctl_led_mutex);
326 if (!snd_ctl_led_card_valid[card_number]) {
327 mutex_unlock(&snd_ctl_led_mutex);
328 snd_card_unref(card);
329 return -ENXIO;
330 }
331 led = &snd_ctl_leds[group];
332 repeat:
333 list_for_each_entry(lctl, &led->controls, list)
334 if (lctl->card == card) {
335 vd = &lctl->kctl->vd[lctl->index_offset];
336 vd->access &= ~group_to_access(group);
337 snd_ctl_led_ctl_destroy(lctl);
338 change = true;
339 goto repeat;
340 }
341 mutex_unlock(&snd_ctl_led_mutex);
342 if (change)
343 snd_ctl_led_set_state(NULL, group_to_access(group), NULL, 0);
344 snd_card_unref(card);
345 return 0;
346 }
347
snd_ctl_led_register(struct snd_card * card)348 static void snd_ctl_led_register(struct snd_card *card)
349 {
350 struct snd_kcontrol *kctl;
351 unsigned int ioff;
352
353 if (snd_BUG_ON(card->number < 0 ||
354 card->number >= ARRAY_SIZE(snd_ctl_led_card_valid)))
355 return;
356 mutex_lock(&snd_ctl_led_mutex);
357 snd_ctl_led_card_valid[card->number] = true;
358 mutex_unlock(&snd_ctl_led_mutex);
359 /* the register callback is already called with held card->controls_rwsem */
360 list_for_each_entry(kctl, &card->controls, list)
361 for (ioff = 0; ioff < kctl->count; ioff++)
362 snd_ctl_led_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, ioff);
363 snd_ctl_led_refresh();
364 snd_ctl_led_sysfs_add(card);
365 }
366
snd_ctl_led_disconnect(struct snd_card * card)367 static void snd_ctl_led_disconnect(struct snd_card *card)
368 {
369 snd_ctl_led_sysfs_remove(card);
370 mutex_lock(&snd_ctl_led_mutex);
371 snd_ctl_led_card_valid[card->number] = false;
372 snd_ctl_led_clean(card);
373 mutex_unlock(&snd_ctl_led_mutex);
374 snd_ctl_led_refresh();
375 }
376
snd_ctl_led_card_release(struct device * dev)377 static void snd_ctl_led_card_release(struct device *dev)
378 {
379 struct snd_ctl_led_card *led_card = to_led_card_dev(dev);
380
381 kfree(led_card);
382 }
383
snd_ctl_led_release(struct device * dev)384 static void snd_ctl_led_release(struct device *dev)
385 {
386 }
387
snd_ctl_led_dev_release(struct device * dev)388 static void snd_ctl_led_dev_release(struct device *dev)
389 {
390 }
391
392 /*
393 * sysfs
394 */
395
mode_show(struct device * dev,struct device_attribute * attr,char * buf)396 static ssize_t mode_show(struct device *dev,
397 struct device_attribute *attr, char *buf)
398 {
399 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
400 const char *str = NULL;
401
402 switch (led->mode) {
403 case MODE_FOLLOW_MUTE: str = "follow-mute"; break;
404 case MODE_FOLLOW_ROUTE: str = "follow-route"; break;
405 case MODE_ON: str = "on"; break;
406 case MODE_OFF: str = "off"; break;
407 }
408 return sysfs_emit(buf, "%s\n", str);
409 }
410
mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)411 static ssize_t mode_store(struct device *dev,
412 struct device_attribute *attr,
413 const char *buf, size_t count)
414 {
415 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
416 char _buf[16];
417 size_t l = min(count, sizeof(_buf) - 1);
418 enum snd_ctl_led_mode mode;
419
420 memcpy(_buf, buf, l);
421 _buf[l] = '\0';
422 if (strstr(_buf, "mute"))
423 mode = MODE_FOLLOW_MUTE;
424 else if (strstr(_buf, "route"))
425 mode = MODE_FOLLOW_ROUTE;
426 else if (strncmp(_buf, "off", 3) == 0 || strncmp(_buf, "0", 1) == 0)
427 mode = MODE_OFF;
428 else if (strncmp(_buf, "on", 2) == 0 || strncmp(_buf, "1", 1) == 0)
429 mode = MODE_ON;
430 else
431 return count;
432
433 mutex_lock(&snd_ctl_led_mutex);
434 led->mode = mode;
435 mutex_unlock(&snd_ctl_led_mutex);
436
437 snd_ctl_led_set_state(NULL, group_to_access(led->group), NULL, 0);
438 return count;
439 }
440
brightness_show(struct device * dev,struct device_attribute * attr,char * buf)441 static ssize_t brightness_show(struct device *dev,
442 struct device_attribute *attr, char *buf)
443 {
444 struct snd_ctl_led *led = container_of(dev, struct snd_ctl_led, dev);
445
446 return sysfs_emit(buf, "%u\n", ledtrig_audio_get(led->trigger_type));
447 }
448
449 static DEVICE_ATTR_RW(mode);
450 static DEVICE_ATTR_RO(brightness);
451
452 static struct attribute *snd_ctl_led_dev_attrs[] = {
453 &dev_attr_mode.attr,
454 &dev_attr_brightness.attr,
455 NULL,
456 };
457
458 static const struct attribute_group snd_ctl_led_dev_attr_group = {
459 .attrs = snd_ctl_led_dev_attrs,
460 };
461
462 static const struct attribute_group *snd_ctl_led_dev_attr_groups[] = {
463 &snd_ctl_led_dev_attr_group,
464 NULL,
465 };
466
find_eos(char * s)467 static char *find_eos(char *s)
468 {
469 while (*s && *s != ',')
470 s++;
471 if (*s)
472 s++;
473 return s;
474 }
475
parse_uint(char * s,unsigned int * val)476 static char *parse_uint(char *s, unsigned int *val)
477 {
478 unsigned long long res;
479 if (kstrtoull(s, 10, &res))
480 res = 0;
481 *val = res;
482 return find_eos(s);
483 }
484
parse_string(char * s,char * val,size_t val_size)485 static char *parse_string(char *s, char *val, size_t val_size)
486 {
487 if (*s == '"' || *s == '\'') {
488 char c = *s;
489 s++;
490 while (*s && *s != c) {
491 if (val_size > 1) {
492 *val++ = *s;
493 val_size--;
494 }
495 s++;
496 }
497 } else {
498 while (*s && *s != ',') {
499 if (val_size > 1) {
500 *val++ = *s;
501 val_size--;
502 }
503 s++;
504 }
505 }
506 *val = '\0';
507 if (*s)
508 s++;
509 return s;
510 }
511
parse_iface(char * s,snd_ctl_elem_iface_t * val)512 static char *parse_iface(char *s, snd_ctl_elem_iface_t *val)
513 {
514 if (!strncasecmp(s, "card", 4))
515 *val = SNDRV_CTL_ELEM_IFACE_CARD;
516 else if (!strncasecmp(s, "mixer", 5))
517 *val = SNDRV_CTL_ELEM_IFACE_MIXER;
518 return find_eos(s);
519 }
520
521 /*
522 * These types of input strings are accepted:
523 *
524 * unsigned integer - numid (equivaled to numid=UINT)
525 * string - basic mixer name (equivalent to iface=MIXER,name=STR)
526 * numid=UINT
527 * [iface=MIXER,][device=UINT,][subdevice=UINT,]name=STR[,index=UINT]
528 */
set_led_id(struct snd_ctl_led_card * led_card,const char * buf,size_t count,bool attach)529 static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, size_t count,
530 bool attach)
531 {
532 char buf2[256], *s, *os;
533 struct snd_ctl_elem_id id;
534 int err;
535
536 if (strscpy(buf2, buf, sizeof(buf2)) < 0)
537 return -E2BIG;
538 memset(&id, 0, sizeof(id));
539 id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
540 s = buf2;
541 while (*s) {
542 os = s;
543 if (!strncasecmp(s, "numid=", 6)) {
544 s = parse_uint(s + 6, &id.numid);
545 } else if (!strncasecmp(s, "iface=", 6)) {
546 s = parse_iface(s + 6, &id.iface);
547 } else if (!strncasecmp(s, "device=", 7)) {
548 s = parse_uint(s + 7, &id.device);
549 } else if (!strncasecmp(s, "subdevice=", 10)) {
550 s = parse_uint(s + 10, &id.subdevice);
551 } else if (!strncasecmp(s, "name=", 5)) {
552 s = parse_string(s + 5, id.name, sizeof(id.name));
553 } else if (!strncasecmp(s, "index=", 6)) {
554 s = parse_uint(s + 6, &id.index);
555 } else if (s == buf2) {
556 while (*s) {
557 if (*s < '0' || *s > '9')
558 break;
559 s++;
560 }
561 if (*s == '\0')
562 parse_uint(buf2, &id.numid);
563 else {
564 for (; *s >= ' '; s++);
565 *s = '\0';
566 strscpy(id.name, buf2, sizeof(id.name));
567 }
568 break;
569 }
570 if (*s == ',')
571 s++;
572 if (s == os)
573 break;
574 }
575
576 err = snd_ctl_led_set_id(led_card->number, &id, led_card->led->group, attach);
577 if (err < 0)
578 return err;
579
580 return count;
581 }
582
attach_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)583 static ssize_t attach_store(struct device *dev,
584 struct device_attribute *attr,
585 const char *buf, size_t count)
586 {
587 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
588 return set_led_id(led_card, buf, count, true);
589 }
590
detach_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)591 static ssize_t detach_store(struct device *dev,
592 struct device_attribute *attr,
593 const char *buf, size_t count)
594 {
595 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
596 return set_led_id(led_card, buf, count, false);
597 }
598
reset_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)599 static ssize_t reset_store(struct device *dev,
600 struct device_attribute *attr,
601 const char *buf, size_t count)
602 {
603 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
604 int err;
605
606 if (count > 0 && buf[0] == '1') {
607 err = snd_ctl_led_reset(led_card->number, led_card->led->group);
608 if (err < 0)
609 return err;
610 }
611 return count;
612 }
613
list_show(struct device * dev,struct device_attribute * attr,char * buf)614 static ssize_t list_show(struct device *dev,
615 struct device_attribute *attr, char *buf)
616 {
617 struct snd_ctl_led_card *led_card = container_of(dev, struct snd_ctl_led_card, dev);
618 struct snd_card *card;
619 struct snd_ctl_led_ctl *lctl;
620 size_t l = 0;
621
622 card = snd_card_ref(led_card->number);
623 if (!card)
624 return -ENXIO;
625 down_read(&card->controls_rwsem);
626 mutex_lock(&snd_ctl_led_mutex);
627 if (snd_ctl_led_card_valid[led_card->number]) {
628 list_for_each_entry(lctl, &led_card->led->controls, list) {
629 if (lctl->card != card)
630 continue;
631 if (l)
632 l += sysfs_emit_at(buf, l, " ");
633 l += sysfs_emit_at(buf, l, "%u",
634 lctl->kctl->id.numid + lctl->index_offset);
635 }
636 }
637 mutex_unlock(&snd_ctl_led_mutex);
638 up_read(&card->controls_rwsem);
639 snd_card_unref(card);
640 return l;
641 }
642
643 static DEVICE_ATTR_WO(attach);
644 static DEVICE_ATTR_WO(detach);
645 static DEVICE_ATTR_WO(reset);
646 static DEVICE_ATTR_RO(list);
647
648 static struct attribute *snd_ctl_led_card_attrs[] = {
649 &dev_attr_attach.attr,
650 &dev_attr_detach.attr,
651 &dev_attr_reset.attr,
652 &dev_attr_list.attr,
653 NULL,
654 };
655
656 static const struct attribute_group snd_ctl_led_card_attr_group = {
657 .attrs = snd_ctl_led_card_attrs,
658 };
659
660 static const struct attribute_group *snd_ctl_led_card_attr_groups[] = {
661 &snd_ctl_led_card_attr_group,
662 NULL,
663 };
664
665 static struct device snd_ctl_led_dev;
666
snd_ctl_led_sysfs_add(struct snd_card * card)667 static void snd_ctl_led_sysfs_add(struct snd_card *card)
668 {
669 unsigned int group;
670 struct snd_ctl_led_card *led_card;
671 struct snd_ctl_led *led;
672 char link_name[32];
673
674 for (group = 0; group < MAX_LED; group++) {
675 led = &snd_ctl_leds[group];
676 led_card = kzalloc(sizeof(*led_card), GFP_KERNEL);
677 if (!led_card)
678 goto cerr2;
679 led_card->number = card->number;
680 led_card->led = led;
681 device_initialize(&led_card->dev);
682 led_card->dev.release = snd_ctl_led_card_release;
683 if (dev_set_name(&led_card->dev, "card%d", card->number) < 0)
684 goto cerr;
685 led_card->dev.parent = &led->dev;
686 led_card->dev.groups = snd_ctl_led_card_attr_groups;
687 if (device_add(&led_card->dev))
688 goto cerr;
689 led->cards[card->number] = led_card;
690 snprintf(link_name, sizeof(link_name), "led-%s", led->name);
691 WARN(sysfs_create_link(&card->ctl_dev->kobj, &led_card->dev.kobj, link_name),
692 "can't create symlink to controlC%i device\n", card->number);
693 WARN(sysfs_create_link(&led_card->dev.kobj, &card->card_dev.kobj, "card"),
694 "can't create symlink to card%i\n", card->number);
695
696 continue;
697 cerr:
698 put_device(&led_card->dev);
699 cerr2:
700 printk(KERN_ERR "snd_ctl_led: unable to add card%d", card->number);
701 }
702 }
703
snd_ctl_led_sysfs_remove(struct snd_card * card)704 static void snd_ctl_led_sysfs_remove(struct snd_card *card)
705 {
706 unsigned int group;
707 struct snd_ctl_led_card *led_card;
708 struct snd_ctl_led *led;
709 char link_name[32];
710
711 for (group = 0; group < MAX_LED; group++) {
712 led = &snd_ctl_leds[group];
713 led_card = led->cards[card->number];
714 if (!led_card)
715 continue;
716 snprintf(link_name, sizeof(link_name), "led-%s", led->name);
717 sysfs_remove_link(&card->ctl_dev->kobj, link_name);
718 sysfs_remove_link(&led_card->dev.kobj, "card");
719 device_unregister(&led_card->dev);
720 led->cards[card->number] = NULL;
721 }
722 }
723
724 /*
725 * Control layer registration
726 */
727 static struct snd_ctl_layer_ops snd_ctl_led_lops = {
728 .module_name = SND_CTL_LAYER_MODULE_LED,
729 .lregister = snd_ctl_led_register,
730 .ldisconnect = snd_ctl_led_disconnect,
731 .lnotify = snd_ctl_led_notify,
732 };
733
snd_ctl_led_init(void)734 static int __init snd_ctl_led_init(void)
735 {
736 struct snd_ctl_led *led;
737 unsigned int group;
738
739 device_initialize(&snd_ctl_led_dev);
740 snd_ctl_led_dev.class = &sound_class;
741 snd_ctl_led_dev.release = snd_ctl_led_dev_release;
742 dev_set_name(&snd_ctl_led_dev, "ctl-led");
743 if (device_add(&snd_ctl_led_dev)) {
744 put_device(&snd_ctl_led_dev);
745 return -ENOMEM;
746 }
747 for (group = 0; group < MAX_LED; group++) {
748 led = &snd_ctl_leds[group];
749 INIT_LIST_HEAD(&led->controls);
750 device_initialize(&led->dev);
751 led->dev.parent = &snd_ctl_led_dev;
752 led->dev.release = snd_ctl_led_release;
753 led->dev.groups = snd_ctl_led_dev_attr_groups;
754 dev_set_name(&led->dev, led->name);
755 if (device_add(&led->dev)) {
756 put_device(&led->dev);
757 for (; group > 0; group--) {
758 led = &snd_ctl_leds[group - 1];
759 device_unregister(&led->dev);
760 }
761 device_unregister(&snd_ctl_led_dev);
762 return -ENOMEM;
763 }
764 }
765 snd_ctl_register_layer(&snd_ctl_led_lops);
766 return 0;
767 }
768
snd_ctl_led_exit(void)769 static void __exit snd_ctl_led_exit(void)
770 {
771 struct snd_ctl_led *led;
772 struct snd_card *card;
773 unsigned int group, card_number;
774
775 snd_ctl_disconnect_layer(&snd_ctl_led_lops);
776 for (card_number = 0; card_number < SNDRV_CARDS; card_number++) {
777 if (!snd_ctl_led_card_valid[card_number])
778 continue;
779 card = snd_card_ref(card_number);
780 if (card) {
781 snd_ctl_led_sysfs_remove(card);
782 snd_card_unref(card);
783 }
784 }
785 for (group = 0; group < MAX_LED; group++) {
786 led = &snd_ctl_leds[group];
787 device_unregister(&led->dev);
788 }
789 device_unregister(&snd_ctl_led_dev);
790 snd_ctl_led_clean(NULL);
791 }
792
793 module_init(snd_ctl_led_init)
794 module_exit(snd_ctl_led_exit)
795
