xref: /openbmc/linux/sound/core/init.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /*
2  *  Initialization routines
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <sound/driver.h>
23 #include <linux/init.h>
24 #include <linux/sched.h>
25 #include <linux/file.h>
26 #include <linux/slab.h>
27 #include <linux/time.h>
28 #include <linux/ctype.h>
29 #include <linux/pci.h>
30 #include <linux/pm.h>
31 #include <linux/platform_device.h>
32 
33 #include <sound/core.h>
34 #include <sound/control.h>
35 #include <sound/info.h>
36 
37 struct snd_shutdown_f_ops {
38 	struct file_operations f_ops;
39 	struct snd_shutdown_f_ops *next;
40 };
41 
42 unsigned int snd_cards_lock = 0;	/* locked for registering/using */
43 snd_card_t *snd_cards[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = NULL};
44 DEFINE_RWLOCK(snd_card_rwlock);
45 
46 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
47 int (*snd_mixer_oss_notify_callback)(snd_card_t *card, int free_flag);
48 #endif
49 
50 static void snd_card_id_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
51 {
52 	snd_iprintf(buffer, "%s\n", entry->card->id);
53 }
54 
55 static void snd_card_free_thread(void * __card);
56 
57 /**
58  *  snd_card_new - create and initialize a soundcard structure
59  *  @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
60  *  @xid: card identification (ASCII string)
61  *  @module: top level module for locking
62  *  @extra_size: allocate this extra size after the main soundcard structure
63  *
64  *  Creates and initializes a soundcard structure.
65  *
66  *  Returns kmallocated snd_card_t structure. Creates the ALSA control interface
67  *  (which is blocked until snd_card_register function is called).
68  */
69 snd_card_t *snd_card_new(int idx, const char *xid,
70 			 struct module *module, int extra_size)
71 {
72 	snd_card_t *card;
73 	int err;
74 
75 	if (extra_size < 0)
76 		extra_size = 0;
77 	card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
78 	if (card == NULL)
79 		return NULL;
80 	if (xid) {
81 		if (!snd_info_check_reserved_words(xid))
82 			goto __error;
83 		strlcpy(card->id, xid, sizeof(card->id));
84 	}
85 	err = 0;
86 	write_lock(&snd_card_rwlock);
87 	if (idx < 0) {
88 		int idx2;
89 		for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
90 			if (~snd_cards_lock & idx & 1<<idx2) {
91 				idx = idx2;
92 				if (idx >= snd_ecards_limit)
93 					snd_ecards_limit = idx + 1;
94 				break;
95 			}
96 	} else if (idx < snd_ecards_limit) {
97 		if (snd_cards_lock & (1 << idx))
98 			err = -ENODEV;	/* invalid */
99 	} else if (idx < SNDRV_CARDS)
100 		snd_ecards_limit = idx + 1; /* increase the limit */
101 	else
102 		err = -ENODEV;
103 	if (idx < 0 || err < 0) {
104 		write_unlock(&snd_card_rwlock);
105 		snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i)\n", idx, snd_ecards_limit - 1);
106 		goto __error;
107 	}
108 	snd_cards_lock |= 1 << idx;		/* lock it */
109 	write_unlock(&snd_card_rwlock);
110 	card->number = idx;
111 	card->module = module;
112 	INIT_LIST_HEAD(&card->devices);
113 	init_rwsem(&card->controls_rwsem);
114 	rwlock_init(&card->ctl_files_rwlock);
115 	INIT_LIST_HEAD(&card->controls);
116 	INIT_LIST_HEAD(&card->ctl_files);
117 	spin_lock_init(&card->files_lock);
118 	init_waitqueue_head(&card->shutdown_sleep);
119 	INIT_WORK(&card->free_workq, snd_card_free_thread, card);
120 #ifdef CONFIG_PM
121 	init_MUTEX(&card->power_lock);
122 	init_waitqueue_head(&card->power_sleep);
123 #endif
124 	/* the control interface cannot be accessed from the user space until */
125 	/* snd_cards_bitmask and snd_cards are set with snd_card_register */
126 	if ((err = snd_ctl_create(card)) < 0) {
127 		snd_printd("unable to register control minors\n");
128 		goto __error;
129 	}
130 	if ((err = snd_info_card_create(card)) < 0) {
131 		snd_printd("unable to create card info\n");
132 		goto __error_ctl;
133 	}
134 	if (extra_size > 0)
135 		card->private_data = (char *)card + sizeof(snd_card_t);
136 	return card;
137 
138       __error_ctl:
139 	snd_device_free_all(card, SNDRV_DEV_CMD_PRE);
140       __error:
141 	kfree(card);
142       	return NULL;
143 }
144 
145 static unsigned int snd_disconnect_poll(struct file * file, poll_table * wait)
146 {
147 	return POLLERR | POLLNVAL;
148 }
149 
150 /**
151  *  snd_card_disconnect - disconnect all APIs from the file-operations (user space)
152  *  @card: soundcard structure
153  *
154  *  Disconnects all APIs from the file-operations (user space).
155  *
156  *  Returns zero, otherwise a negative error code.
157  *
158  *  Note: The current implementation replaces all active file->f_op with special
159  *        dummy file operations (they do nothing except release).
160  */
161 int snd_card_disconnect(snd_card_t * card)
162 {
163 	struct snd_monitor_file *mfile;
164 	struct file *file;
165 	struct snd_shutdown_f_ops *s_f_ops;
166 	struct file_operations *f_ops, *old_f_ops;
167 	int err;
168 
169 	spin_lock(&card->files_lock);
170 	if (card->shutdown) {
171 		spin_unlock(&card->files_lock);
172 		return 0;
173 	}
174 	card->shutdown = 1;
175 	spin_unlock(&card->files_lock);
176 
177 	/* phase 1: disable fops (user space) operations for ALSA API */
178 	write_lock(&snd_card_rwlock);
179 	snd_cards[card->number] = NULL;
180 	write_unlock(&snd_card_rwlock);
181 
182 	/* phase 2: replace file->f_op with special dummy operations */
183 
184 	spin_lock(&card->files_lock);
185 	mfile = card->files;
186 	while (mfile) {
187 		file = mfile->file;
188 
189 		/* it's critical part, use endless loop */
190 		/* we have no room to fail */
191 		s_f_ops = kmalloc(sizeof(struct snd_shutdown_f_ops), GFP_ATOMIC);
192 		if (s_f_ops == NULL)
193 			panic("Atomic allocation failed for snd_shutdown_f_ops!");
194 
195 		f_ops = &s_f_ops->f_ops;
196 
197 		memset(f_ops, 0, sizeof(*f_ops));
198 		f_ops->owner = file->f_op->owner;
199 		f_ops->release = file->f_op->release;
200 		f_ops->poll = snd_disconnect_poll;
201 
202 		s_f_ops->next = card->s_f_ops;
203 		card->s_f_ops = s_f_ops;
204 
205 		f_ops = fops_get(f_ops);
206 
207 		old_f_ops = file->f_op;
208 		file->f_op = f_ops;	/* must be atomic */
209 		fops_put(old_f_ops);
210 
211 		mfile = mfile->next;
212 	}
213 	spin_unlock(&card->files_lock);
214 
215 	/* phase 3: notify all connected devices about disconnection */
216 	/* at this point, they cannot respond to any calls except release() */
217 
218 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
219 	if (snd_mixer_oss_notify_callback)
220 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_DISCONNECT);
221 #endif
222 
223 	/* notify all devices that we are disconnected */
224 	err = snd_device_disconnect_all(card);
225 	if (err < 0)
226 		snd_printk(KERN_ERR "not all devices for card %i can be disconnected\n", card->number);
227 
228 	return 0;
229 }
230 
231 #ifdef CONFIG_SND_GENERIC_DRIVER
232 static void snd_generic_device_unregister(snd_card_t *card);
233 #else
234 #define snd_generic_device_unregister(x) /*NOP*/
235 #endif
236 
237 /**
238  *  snd_card_free - frees given soundcard structure
239  *  @card: soundcard structure
240  *
241  *  This function releases the soundcard structure and the all assigned
242  *  devices automatically.  That is, you don't have to release the devices
243  *  by yourself.
244  *
245  *  Returns zero. Frees all associated devices and frees the control
246  *  interface associated to given soundcard.
247  */
248 int snd_card_free(snd_card_t * card)
249 {
250 	struct snd_shutdown_f_ops *s_f_ops;
251 
252 	if (card == NULL)
253 		return -EINVAL;
254 	write_lock(&snd_card_rwlock);
255 	snd_cards[card->number] = NULL;
256 	write_unlock(&snd_card_rwlock);
257 
258 #ifdef CONFIG_PM
259 	wake_up(&card->power_sleep);
260 #endif
261 	/* wait, until all devices are ready for the free operation */
262 	wait_event(card->shutdown_sleep, card->files == NULL);
263 
264 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
265 	if (snd_mixer_oss_notify_callback)
266 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_FREE);
267 #endif
268 	if (snd_device_free_all(card, SNDRV_DEV_CMD_PRE) < 0) {
269 		snd_printk(KERN_ERR "unable to free all devices (pre)\n");
270 		/* Fatal, but this situation should never occur */
271 	}
272 	if (snd_device_free_all(card, SNDRV_DEV_CMD_NORMAL) < 0) {
273 		snd_printk(KERN_ERR "unable to free all devices (normal)\n");
274 		/* Fatal, but this situation should never occur */
275 	}
276 	if (snd_device_free_all(card, SNDRV_DEV_CMD_POST) < 0) {
277 		snd_printk(KERN_ERR "unable to free all devices (post)\n");
278 		/* Fatal, but this situation should never occur */
279 	}
280 	if (card->private_free)
281 		card->private_free(card);
282 	if (card->proc_id)
283 		snd_info_unregister(card->proc_id);
284 	if (snd_info_card_free(card) < 0) {
285 		snd_printk(KERN_WARNING "unable to free card info\n");
286 		/* Not fatal error */
287 	}
288 	snd_generic_device_unregister(card);
289 	while (card->s_f_ops) {
290 		s_f_ops = card->s_f_ops;
291 		card->s_f_ops = s_f_ops->next;
292 		kfree(s_f_ops);
293 	}
294 	write_lock(&snd_card_rwlock);
295 	snd_cards_lock &= ~(1 << card->number);
296 	write_unlock(&snd_card_rwlock);
297 	kfree(card);
298 	return 0;
299 }
300 
301 static void snd_card_free_thread(void * __card)
302 {
303 	snd_card_t *card = __card;
304 	struct module * module = card->module;
305 
306 	if (!try_module_get(module)) {
307 		snd_printk(KERN_ERR "unable to lock toplevel module for card %i in free thread\n", card->number);
308 		module = NULL;
309 	}
310 
311 	snd_card_free(card);
312 
313 	module_put(module);
314 }
315 
316 /**
317  *  snd_card_free_in_thread - call snd_card_free() in thread
318  *  @card: soundcard structure
319  *
320  *  This function schedules the call of snd_card_free() function in a
321  *  work queue.  When all devices are released (non-busy), the work
322  *  is woken up and calls snd_card_free().
323  *
324  *  When a card can be disconnected at any time by hotplug service,
325  *  this function should be used in disconnect (or detach) callback
326  *  instead of calling snd_card_free() directly.
327  *
328  *  Returns - zero otherwise a negative error code if the start of thread failed.
329  */
330 int snd_card_free_in_thread(snd_card_t * card)
331 {
332 	if (card->files == NULL) {
333 		snd_card_free(card);
334 		return 0;
335 	}
336 
337 	if (schedule_work(&card->free_workq))
338 		return 0;
339 
340 	snd_printk(KERN_ERR "schedule_work() failed in snd_card_free_in_thread for card %i\n", card->number);
341 	/* try to free the structure immediately */
342 	snd_card_free(card);
343 	return -EFAULT;
344 }
345 
346 static void choose_default_id(snd_card_t * card)
347 {
348 	int i, len, idx_flag = 0, loops = 8;
349 	char *id, *spos;
350 
351 	id = spos = card->shortname;
352 	while (*id != '\0') {
353 		if (*id == ' ')
354 			spos = id + 1;
355 		id++;
356 	}
357 	id = card->id;
358 	while (*spos != '\0' && !isalnum(*spos))
359 		spos++;
360 	if (isdigit(*spos))
361 		*id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
362 	while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
363 		if (isalnum(*spos))
364 			*id++ = *spos;
365 		spos++;
366 	}
367 	*id = '\0';
368 
369 	id = card->id;
370 
371 	if (*id == '\0')
372 		strcpy(id, "default");
373 
374 	while (1) {
375 	      	if (loops-- == 0) {
376       			snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
377       			strcpy(card->id, card->proc_root->name);
378       			return;
379       		}
380 	      	if (!snd_info_check_reserved_words(id))
381       			goto __change;
382 		for (i = 0; i < snd_ecards_limit; i++) {
383 			if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
384 				goto __change;
385 		}
386 		break;
387 
388 	      __change:
389 		len = strlen(id);
390 		if (idx_flag)
391 			id[len-1]++;
392 		else if ((size_t)len <= sizeof(card->id) - 3) {
393 			strcat(id, "_1");
394 			idx_flag++;
395 		} else {
396 			spos = id + len - 2;
397 			if ((size_t)len <= sizeof(card->id) - 2)
398 				spos++;
399 			*spos++ = '_';
400 			*spos++ = '1';
401 			*spos++ = '\0';
402 			idx_flag++;
403 		}
404 	}
405 }
406 
407 /**
408  *  snd_card_register - register the soundcard
409  *  @card: soundcard structure
410  *
411  *  This function registers all the devices assigned to the soundcard.
412  *  Until calling this, the ALSA control interface is blocked from the
413  *  external accesses.  Thus, you should call this function at the end
414  *  of the initialization of the card.
415  *
416  *  Returns zero otherwise a negative error code if the registrain failed.
417  */
418 int snd_card_register(snd_card_t * card)
419 {
420 	int err;
421 	snd_info_entry_t *entry;
422 
423 	snd_runtime_check(card != NULL, return -EINVAL);
424 	if ((err = snd_device_register_all(card)) < 0)
425 		return err;
426 	write_lock(&snd_card_rwlock);
427 	if (snd_cards[card->number]) {
428 		/* already registered */
429 		write_unlock(&snd_card_rwlock);
430 		return 0;
431 	}
432 	if (card->id[0] == '\0')
433 		choose_default_id(card);
434 	snd_cards[card->number] = card;
435 	write_unlock(&snd_card_rwlock);
436 	if ((err = snd_info_card_register(card)) < 0) {
437 		snd_printd("unable to create card info\n");
438 		goto __skip_info;
439 	}
440 	if ((entry = snd_info_create_card_entry(card, "id", card->proc_root)) == NULL) {
441 		snd_printd("unable to create card entry\n");
442 		goto __skip_info;
443 	}
444 	entry->c.text.read_size = PAGE_SIZE;
445 	entry->c.text.read = snd_card_id_read;
446 	if (snd_info_register(entry) < 0) {
447 		snd_info_free_entry(entry);
448 		entry = NULL;
449 	}
450 	card->proc_id = entry;
451       __skip_info:
452 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
453 	if (snd_mixer_oss_notify_callback)
454 		snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER);
455 #endif
456 	return 0;
457 }
458 
459 static snd_info_entry_t *snd_card_info_entry = NULL;
460 
461 static void snd_card_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
462 {
463 	int idx, count;
464 	snd_card_t *card;
465 
466 	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
467 		read_lock(&snd_card_rwlock);
468 		if ((card = snd_cards[idx]) != NULL) {
469 			count++;
470 			snd_iprintf(buffer, "%i [%-15s]: %s - %s\n",
471 					idx,
472 					card->id,
473 					card->driver,
474 					card->shortname);
475 			snd_iprintf(buffer, "                     %s\n",
476 					card->longname);
477 		}
478 		read_unlock(&snd_card_rwlock);
479 	}
480 	if (!count)
481 		snd_iprintf(buffer, "--- no soundcards ---\n");
482 }
483 
484 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
485 
486 void snd_card_info_read_oss(snd_info_buffer_t * buffer)
487 {
488 	int idx, count;
489 	snd_card_t *card;
490 
491 	for (idx = count = 0; idx < SNDRV_CARDS; idx++) {
492 		read_lock(&snd_card_rwlock);
493 		if ((card = snd_cards[idx]) != NULL) {
494 			count++;
495 			snd_iprintf(buffer, "%s\n", card->longname);
496 		}
497 		read_unlock(&snd_card_rwlock);
498 	}
499 	if (!count) {
500 		snd_iprintf(buffer, "--- no soundcards ---\n");
501 	}
502 }
503 
504 #endif
505 
506 #ifdef MODULE
507 static snd_info_entry_t *snd_card_module_info_entry;
508 static void snd_card_module_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
509 {
510 	int idx;
511 	snd_card_t *card;
512 
513 	for (idx = 0; idx < SNDRV_CARDS; idx++) {
514 		read_lock(&snd_card_rwlock);
515 		if ((card = snd_cards[idx]) != NULL)
516 			snd_iprintf(buffer, "%i %s\n", idx, card->module->name);
517 		read_unlock(&snd_card_rwlock);
518 	}
519 }
520 #endif
521 
522 int __init snd_card_info_init(void)
523 {
524 	snd_info_entry_t *entry;
525 
526 	entry = snd_info_create_module_entry(THIS_MODULE, "cards", NULL);
527 	snd_runtime_check(entry != NULL, return -ENOMEM);
528 	entry->c.text.read_size = PAGE_SIZE;
529 	entry->c.text.read = snd_card_info_read;
530 	if (snd_info_register(entry) < 0) {
531 		snd_info_free_entry(entry);
532 		return -ENOMEM;
533 	}
534 	snd_card_info_entry = entry;
535 
536 #ifdef MODULE
537 	entry = snd_info_create_module_entry(THIS_MODULE, "modules", NULL);
538 	if (entry) {
539 		entry->c.text.read_size = PAGE_SIZE;
540 		entry->c.text.read = snd_card_module_info_read;
541 		if (snd_info_register(entry) < 0)
542 			snd_info_free_entry(entry);
543 		else
544 			snd_card_module_info_entry = entry;
545 	}
546 #endif
547 
548 	return 0;
549 }
550 
551 int __exit snd_card_info_done(void)
552 {
553 	if (snd_card_info_entry)
554 		snd_info_unregister(snd_card_info_entry);
555 #ifdef MODULE
556 	if (snd_card_module_info_entry)
557 		snd_info_unregister(snd_card_module_info_entry);
558 #endif
559 	return 0;
560 }
561 
562 /**
563  *  snd_component_add - add a component string
564  *  @card: soundcard structure
565  *  @component: the component id string
566  *
567  *  This function adds the component id string to the supported list.
568  *  The component can be referred from the alsa-lib.
569  *
570  *  Returns zero otherwise a negative error code.
571  */
572 
573 int snd_component_add(snd_card_t *card, const char *component)
574 {
575 	char *ptr;
576 	int len = strlen(component);
577 
578 	ptr = strstr(card->components, component);
579 	if (ptr != NULL) {
580 		if (ptr[len] == '\0' || ptr[len] == ' ')	/* already there */
581 			return 1;
582 	}
583 	if (strlen(card->components) + 1 + len + 1 > sizeof(card->components)) {
584 		snd_BUG();
585 		return -ENOMEM;
586 	}
587 	if (card->components[0] != '\0')
588 		strcat(card->components, " ");
589 	strcat(card->components, component);
590 	return 0;
591 }
592 
593 /**
594  *  snd_card_file_add - add the file to the file list of the card
595  *  @card: soundcard structure
596  *  @file: file pointer
597  *
598  *  This function adds the file to the file linked-list of the card.
599  *  This linked-list is used to keep tracking the connection state,
600  *  and to avoid the release of busy resources by hotplug.
601  *
602  *  Returns zero or a negative error code.
603  */
604 int snd_card_file_add(snd_card_t *card, struct file *file)
605 {
606 	struct snd_monitor_file *mfile;
607 
608 	mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
609 	if (mfile == NULL)
610 		return -ENOMEM;
611 	mfile->file = file;
612 	mfile->next = NULL;
613 	spin_lock(&card->files_lock);
614 	if (card->shutdown) {
615 		spin_unlock(&card->files_lock);
616 		kfree(mfile);
617 		return -ENODEV;
618 	}
619 	mfile->next = card->files;
620 	card->files = mfile;
621 	spin_unlock(&card->files_lock);
622 	return 0;
623 }
624 
625 /**
626  *  snd_card_file_remove - remove the file from the file list
627  *  @card: soundcard structure
628  *  @file: file pointer
629  *
630  *  This function removes the file formerly added to the card via
631  *  snd_card_file_add() function.
632  *  If all files are removed and the release of the card is
633  *  scheduled, it will wake up the the thread to call snd_card_free()
634  *  (see snd_card_free_in_thread() function).
635  *
636  *  Returns zero or a negative error code.
637  */
638 int snd_card_file_remove(snd_card_t *card, struct file *file)
639 {
640 	struct snd_monitor_file *mfile, *pfile = NULL;
641 
642 	spin_lock(&card->files_lock);
643 	mfile = card->files;
644 	while (mfile) {
645 		if (mfile->file == file) {
646 			if (pfile)
647 				pfile->next = mfile->next;
648 			else
649 				card->files = mfile->next;
650 			break;
651 		}
652 		pfile = mfile;
653 		mfile = mfile->next;
654 	}
655 	spin_unlock(&card->files_lock);
656 	if (card->files == NULL)
657 		wake_up(&card->shutdown_sleep);
658 	if (!mfile) {
659 		snd_printk(KERN_ERR "ALSA card file remove problem (%p)\n", file);
660 		return -ENOENT;
661 	}
662 	kfree(mfile);
663 	return 0;
664 }
665 
666 #ifdef CONFIG_SND_GENERIC_DRIVER
667 /*
668  * generic device without a proper bus using platform_device
669  * (e.g. ISA)
670  */
671 struct snd_generic_device {
672 	struct platform_device pdev;
673 	snd_card_t *card;
674 };
675 
676 #define get_snd_generic_card(dev)	container_of(to_platform_device(dev), struct snd_generic_device, pdev)->card
677 
678 #define SND_GENERIC_NAME	"snd_generic"
679 
680 #ifdef CONFIG_PM
681 static int snd_generic_suspend(struct device *dev, pm_message_t state);
682 static int snd_generic_resume(struct device *dev);
683 #endif
684 
685 /* initialized in sound.c */
686 struct device_driver snd_generic_driver = {
687 	.name		= SND_GENERIC_NAME,
688 	.bus		= &platform_bus_type,
689 #ifdef CONFIG_PM
690 	.suspend	= snd_generic_suspend,
691 	.resume		= snd_generic_resume,
692 #endif
693 };
694 
695 void snd_generic_device_release(struct device *dev)
696 {
697 }
698 
699 static int snd_generic_device_register(snd_card_t *card)
700 {
701 	struct snd_generic_device *dev;
702 	int err;
703 
704 	if (card->generic_dev)
705 		return 0; /* already registered */
706 
707 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
708 	if (! dev) {
709 		snd_printk(KERN_ERR "can't allocate generic_device\n");
710 		return -ENOMEM;
711 	}
712 
713 	dev->pdev.name = SND_GENERIC_NAME;
714 	dev->pdev.id = card->number;
715 	dev->pdev.dev.release = snd_generic_device_release;
716 	dev->card = card;
717 	if ((err = platform_device_register(&dev->pdev)) < 0) {
718 		kfree(dev);
719 		return err;
720 	}
721 	card->generic_dev = dev;
722 	return 0;
723 }
724 
725 static void snd_generic_device_unregister(snd_card_t *card)
726 {
727 	struct snd_generic_device *dev = card->generic_dev;
728 	if (dev) {
729 		platform_device_unregister(&dev->pdev);
730 		kfree(dev);
731 		card->generic_dev = NULL;
732 	}
733 }
734 
735 /**
736  * snd_card_set_generic_dev - assign the generic device to the card
737  * @card: soundcard structure
738  *
739  * Assigns a generic device to the card.  This function is provided as the
740  * last resort, for devices without any proper bus.  Thus this won't override
741  * the device already assigned to the card.
742  *
743  * Returns zero if successful, or a negative error code.
744  */
745 int snd_card_set_generic_dev(snd_card_t *card)
746 {
747 	int err;
748 	if ((err = snd_generic_device_register(card)) < 0)
749 		return err;
750 	if (! card->dev)
751 		snd_card_set_dev(card, &card->generic_dev->pdev.dev);
752 	return 0;
753 }
754 #endif /* CONFIG_SND_GENERIC_DRIVER */
755 
756 #ifdef CONFIG_PM
757 /**
758  *  snd_power_wait - wait until the power-state is changed.
759  *  @card: soundcard structure
760  *  @power_state: expected power state
761  *  @file: file structure for the O_NONBLOCK check (optional)
762  *
763  *  Waits until the power-state is changed.
764  *
765  *  Note: the power lock must be active before call.
766  */
767 int snd_power_wait(snd_card_t *card, unsigned int power_state, struct file *file)
768 {
769 	wait_queue_t wait;
770 	int result = 0;
771 
772 	/* fastpath */
773 	if (snd_power_get_state(card) == power_state)
774 		return 0;
775 	init_waitqueue_entry(&wait, current);
776 	add_wait_queue(&card->power_sleep, &wait);
777 	while (1) {
778 		if (card->shutdown) {
779 			result = -ENODEV;
780 			break;
781 		}
782 		if (snd_power_get_state(card) == power_state)
783 			break;
784 #if 0 /* block all devices */
785 		if (file && (file->f_flags & O_NONBLOCK)) {
786 			result = -EAGAIN;
787 			break;
788 		}
789 #endif
790 		set_current_state(TASK_UNINTERRUPTIBLE);
791 		snd_power_unlock(card);
792 		schedule_timeout(30 * HZ);
793 		snd_power_lock(card);
794 	}
795 	remove_wait_queue(&card->power_sleep, &wait);
796 	return result;
797 }
798 
799 /**
800  * snd_card_set_pm_callback - set the PCI power-management callbacks
801  * @card: soundcard structure
802  * @suspend: suspend callback function
803  * @resume: resume callback function
804  * @private_data: private data to pass to the callback functions
805  *
806  * Sets the power-management callback functions of the card.
807  * These callbacks are called from ALSA's common PCI suspend/resume
808  * handler and from the control API.
809  */
810 int snd_card_set_pm_callback(snd_card_t *card,
811 			     int (*suspend)(snd_card_t *, pm_message_t),
812 			     int (*resume)(snd_card_t *),
813 			     void *private_data)
814 {
815 	card->pm_suspend = suspend;
816 	card->pm_resume = resume;
817 	card->pm_private_data = private_data;
818 	return 0;
819 }
820 
821 #ifdef CONFIG_SND_GENERIC_DRIVER
822 /* suspend/resume callbacks for snd_generic platform device */
823 static int snd_generic_suspend(struct device *dev, pm_message_t state)
824 {
825 	snd_card_t *card;
826 
827 	card = get_snd_generic_card(dev);
828 	if (card->power_state == SNDRV_CTL_POWER_D3hot)
829 		return 0;
830 	if (card->pm_suspend)
831 		card->pm_suspend(card, PMSG_SUSPEND);
832 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
833 	return 0;
834 }
835 
836 static int snd_generic_resume(struct device *dev)
837 {
838 	snd_card_t *card;
839 
840 	card = get_snd_generic_card(dev);
841 	if (card->power_state == SNDRV_CTL_POWER_D0)
842 		return 0;
843 	if (card->pm_suspend)
844 		card->pm_resume(card);
845 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
846 	return 0;
847 }
848 
849 /**
850  * snd_card_set_generic_pm_callback - set the generic power-management callbacks
851  * @card: soundcard structure
852  * @suspend: suspend callback function
853  * @resume: resume callback function
854  * @private_data: private data to pass to the callback functions
855  *
856  * Registers the power-management and sets the lowlevel callbacks for
857  * the given card.  These callbacks are called from the ALSA's common
858  * PM handler and from the control API.
859  */
860 int snd_card_set_generic_pm_callback(snd_card_t *card,
861 				 int (*suspend)(snd_card_t *, pm_message_t),
862 				 int (*resume)(snd_card_t *),
863 				 void *private_data)
864 {
865 	int err;
866 	if ((err = snd_generic_device_register(card)) < 0)
867 		return err;
868 	return snd_card_set_pm_callback(card, suspend, resume, private_data);
869 }
870 #endif /* CONFIG_SND_GENERIC_DRIVER */
871 
872 #ifdef CONFIG_PCI
873 int snd_card_pci_suspend(struct pci_dev *dev, pm_message_t state)
874 {
875 	snd_card_t *card = pci_get_drvdata(dev);
876 	int err;
877 	if (! card || ! card->pm_suspend)
878 		return 0;
879 	if (card->power_state == SNDRV_CTL_POWER_D3hot)
880 		return 0;
881 	err = card->pm_suspend(card, PMSG_SUSPEND);
882 	pci_save_state(dev);
883 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
884 	return err;
885 }
886 
887 int snd_card_pci_resume(struct pci_dev *dev)
888 {
889 	snd_card_t *card = pci_get_drvdata(dev);
890 	if (! card || ! card->pm_resume)
891 		return 0;
892 	if (card->power_state == SNDRV_CTL_POWER_D0)
893 		return 0;
894 	/* restore the PCI config space */
895 	pci_restore_state(dev);
896 	card->pm_resume(card);
897 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
898 	return 0;
899 }
900 #endif
901 
902 #endif /* CONFIG_PM */
903