summaryrefslogtreecommitdiffstats
path: root/sound/core/control.c
blob: 48ef0a09a7a71ad964aac00a79404945e6102d22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
/*
 *  Routines for driver control interface
 *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <sound/driver.h>
#include <linux/threads.h>
#include <linux/interrupt.h>
#include <linux/smp_lock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/time.h>
#include <sound/core.h>
#include <sound/minors.h>
#include <sound/info.h>
#include <sound/control.h>

/* max number of user-defined controls */
#define MAX_USER_CONTROLS	32

struct snd_kctl_ioctl {
	struct list_head list;		/* list of all ioctls */
	snd_kctl_ioctl_func_t fioctl;
};

static DECLARE_RWSEM(snd_ioctl_rwsem);
static LIST_HEAD(snd_control_ioctls);
#ifdef CONFIG_COMPAT
static LIST_HEAD(snd_control_compat_ioctls);
#endif

static int snd_ctl_open(struct inode *inode, struct file *file)
{
	unsigned long flags;
	struct snd_card *card;
	struct snd_ctl_file *ctl;
	int err;

	card = snd_lookup_minor_data(iminor(inode), SNDRV_DEVICE_TYPE_CONTROL);
	if (!card) {
		err = -ENODEV;
		goto __error1;
	}
	err = snd_card_file_add(card, file);
	if (err < 0) {
		err = -ENODEV;
		goto __error1;
	}
	if (!try_module_get(card->module)) {
		err = -EFAULT;
		goto __error2;
	}
	ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
	if (ctl == NULL) {
		err = -ENOMEM;
		goto __error;
	}
	INIT_LIST_HEAD(&ctl->events);
	init_waitqueue_head(&ctl->change_sleep);
	spin_lock_init(&ctl->read_lock);
	ctl->card = card;
	ctl->prefer_pcm_subdevice = -1;
	ctl->prefer_rawmidi_subdevice = -1;
	ctl->pid = current->pid;
	file->private_data = ctl;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_add_tail(&ctl->list, &card->ctl_files);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
	return 0;

      __error:
	module_put(card->module);
      __error2:
	snd_card_file_remove(card, file);
      __error1:
      	return err;
}

static void snd_ctl_empty_read_queue(struct snd_ctl_file * ctl)
{
	struct snd_kctl_event *cread;
	
	spin_lock(&ctl->read_lock);
	while (!list_empty(&ctl->events)) {
		cread = snd_kctl_event(ctl->events.next);
		list_del(&cread->list);
		kfree(cread);
	}
	spin_unlock(&ctl->read_lock);
}

static int snd_ctl_release(struct inode *inode, struct file *file)
{
	unsigned long flags;
	struct list_head *list;
	struct snd_card *card;
	struct snd_ctl_file *ctl;
	struct snd_kcontrol *control;
	unsigned int idx;

	ctl = file->private_data;
	fasync_helper(-1, file, 0, &ctl->fasync);
	file->private_data = NULL;
	card = ctl->card;
	write_lock_irqsave(&card->ctl_files_rwlock, flags);
	list_del(&ctl->list);
	write_unlock_irqrestore(&card->ctl_files_rwlock, flags);
	down_write(&card->controls_rwsem);
	list_for_each(list, &card->controls) {
		control = snd_kcontrol(list);
		for (idx = 0; idx < control->count; idx++)
			if (control->vd[idx].owner == ctl)
				control->vd[idx].owner = NULL;
	}
	up_write(&card->controls_rwsem);
	snd_ctl_empty_read_queue(ctl);
	kfree(ctl);
	module_put(card->module);
	snd_card_file_remove(card, file);
	return 0;
}

void snd_ctl_notify(struct snd_card *card, unsigned int mask,
		    struct snd_ctl_elem_id *id)
{
	unsigned long flags;
	struct list_head *flist;
	struct snd_ctl_file *ctl;
	struct snd_kctl_event *ev;
	
	snd_assert(card != NULL && id != NULL, return);
	read_lock(&card->ctl_files_rwlock);
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
	card->mixer_oss_change_count++;
#endif
	list_for_each(flist, &card->ctl_files) {
		struct list_head *elist;
		ctl = snd_ctl_file(flist);
		if (!ctl->subscribed)
			continue;
		spin_lock_irqsave(&ctl->read_lock, flags);
		list_for_each(elist, &ctl->events) {
			ev = snd_kctl_event(elist);
			if (ev->id.numid == id->numid) {
				ev->mask |= mask;
				goto _found;
			}
		}
		ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
		if (ev) {
			ev->id = *id;
			ev->mask = mask;
			list_add_tail(&ev->list, &ctl->events);
		} else {
			snd_printk(KERN_ERR "No memory available to allocate event\n");
		}
	_found:
		wake_up(&ctl->change_sleep);
		spin_unlock_irqrestore(&ctl->read_lock, flags);
		kill_fasync(&ctl->fasync, SIGIO, POLL_IN);
	}
	read_unlock(&card->ctl_files_rwlock);
}

EXPORT_SYMBOL(snd_ctl_notify);

/**
 * snd_ctl_new - create a control instance from the template
 * @control: the control template
 * @access: the default control access
 *
 * Allocates a new struct snd_kcontrol instance and copies the given template 
 * to the new instance. It does not copy volatile data (access).
 *
 * Returns the pointer of the new instance, or NULL on failure.
 */
struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control, unsigned int access)
{
	struct snd_kcontrol *kctl;
	unsigned int idx;
	
	snd_assert(control != NULL, return NULL);
	snd_assert(control->count > 0, return NULL);
	kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
	if (kctl == NULL) {
		snd_printk(KERN_ERR "Cannot allocate control instance\n");
		return NULL;
	}
	*kctl = *control;
	for (idx = 0; idx < kctl->count; idx++)
		kctl->vd[idx].access = access;
	return kctl;
}

EXPORT_SYMBOL(snd_ctl_new);

/**
 * snd_ctl_new1 - create a control instance from the template
 * @ncontrol: the initialization record
 * @private_data: the private data to set
 *
 * Allocates a new struct snd_kcontrol instance and initialize from the given 
 * template.  When the access field of ncontrol is 0, it's assumed as
 * READWRITE access. When the count field is 0, it's assumes as one.
 *
 * Returns the pointer of the newly generated instance, or NULL on failure.
 */
struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new *ncontrol,
				  void *private_data)
{
	struct snd_kcontrol kctl;
	unsigned int access;
	
	snd_assert(ncontrol != NULL, return NULL);
	snd_assert(ncontrol->info != NULL, return NULL);
	memset(&kctl, 0, sizeof(kctl));
	kctl.id.iface = ncontrol->iface;
	kctl.id.device = ncontrol->device;
	kctl.id.subdevice = ncontrol->subdevice;
	if (ncontrol->name)
		strlcpy(kctl.id.name, ncontrol->name, sizeof(kctl.id.name));
	kctl.id.index = ncontrol->index;
	kctl.count = ncontrol->count ? ncontrol->count : 1;
	access = ncontrol->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
		 (ncontrol->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
				      SNDRV_CTL_ELEM_ACCESS_INACTIVE|
		 		      SNDRV_CTL_ELEM_ACCESS_DINDIRECT|
		 		      SNDRV_CTL_ELEM_ACCESS_INDIRECT|
		 		      SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE|
		 		      SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK));
	kctl.info = ncontrol->info;
	kctl.get = ncontrol->get;
	kctl.put = ncontrol->put;
	kctl.tlv.p = ncontrol->tlv.p;
	kctl.private_value = ncontrol->private_value;
	kctl.private_data = private_data;
	return snd_ctl_new(&kctl, access);
}

EXPORT_SYMBOL(snd_ctl_new1);

/**
 * snd_ctl_free_one - release the control instance
 * @kcontrol: the control instance
 *
 * Releases the control instance created via snd_ctl_new()
 * or snd_ctl_new1().
 * Don't call this after the control was added to the card.
 */
void snd_ctl_free_one(struct snd_kcontrol *kcontrol)
{
	if (kcontrol) {
		if (kcontrol->private_free)
			kcontrol->private_free(kcontrol);
		kfree(kcontrol);
	}
}

EXPORT_SYMBOL(snd_ctl_free_one);

static unsigned int snd_ctl_hole_check(struct snd_card *card,
				       unsigned int count)
{
	struct list_head *list;
	struct snd_kcontrol *kctl;

	list_for_each(list, &card->controls) {
		kctl = snd_kcontrol(list);
		if ((kctl->id.numid <= card->last_numid &&
		     kctl->id.numid + kctl->count > card->last_numid) ||
		    (kctl->id.numid <= card->last_numid + count - 1 &&
		     kctl->id.numid + kctl->count > card->last_numid + count - 1))
		    	return card->last_numid = kctl->id.numid + kctl->count - 1;
	}
	return card->last_numid;
}

static int snd_ctl_find_hole(struct snd_card *card, unsigned int count)
{
	unsigned int last_numid, iter = 100000;

	last_numid = card->last_numid;
	while (last_numid != snd_ctl_hole_check(card, count)) {
		if (--iter == 0) {
			/* this situation is very unlikely */
			snd_printk(KERN_ERR "unable to allocate new control numid\n");
			return -ENOMEM;
		}
		last_numid = card->last_numid;
	}
	return 0;
}

/**
 * snd_ctl_add - add the control instance to the card
 * @card: the card instance
 * @kcontrol: the control instance to add
 *
 * Adds the control instance created via snd_ctl_new() or
 * snd_ctl_new1() to the given card. Assigns also an unique
 * numid used for fast search.
 *
 * Returns zero if successful, or a negative error code on failure.
 *
 * It frees automatically the control which cannot be added.
 */
int snd_ctl_add(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
	struct snd_ctl_elem_id id;
	unsigned int idx;
	int err = -EINVAL;

	if (! kcontrol)
		return err;
	snd_assert(card != NULL, goto error);
	snd_assert(kcontrol->info != NULL, goto error);
	id = kcontrol->id;
	down_write(&card->controls_rwsem);
	if (snd_ctl_find_id(card, &id)) {
		up_write(&card->controls_rwsem);
		snd_printd(KERN_ERR "control %i:%i:%i:%s:%i is already present\n",
					id.iface,
					id.device,
					id.subdevice,
					id.name,
					id.index);
		err = -EBUSY;
		goto error;
	}
	if (snd_ctl_find_hole(card, kcontrol->count) < 0) {
		up_write(&card->controls_rwsem);
		err = -ENOMEM;
		goto error;
	}
	list_add_tail(&kcontrol->list, &card->controls);
	card->controls_count += kcontrol->count;
	kcontrol->id.numid = card->last_numid + 1;
	card->last_numid += kcontrol->count;
	up_write(&card->controls_rwsem);
	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
	return 0;

 error:
	snd_ctl_free_one(kcontrol);
	return err;
}

EXPORT_SYMBOL(snd_ctl_add);

/**
 * snd_ctl_remove - remove the control from the card and release it
 * @card: the card instance
 * @kcontrol: the control instance to remove
 *
 * Removes the control from the card and then releases the instance.
 * You don't need to call snd_ctl_free_one(). You must be in
 * the write lock - down_write(&card->controls_rwsem).
 * 
 * Returns 0 if successful, or a negative error code on failure.
 */
int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
	struct snd_ctl_elem_id id;
	unsigned int idx;

	snd_assert(card != NULL && kcontrol != NULL, return -EINVAL);
	list_del(&kcontrol->list);
	card->controls_count -= kcontrol->count;
	id = kcontrol->id;
	for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
		snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
	snd_ctl_free_one(kcontrol);
	return 0;
}

EXPORT_SYMBOL(snd_ctl_remove);

/**
 * snd_ctl_remove_id - remove the control of the given id and release it
 * @card: the card instance
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
 * 
 * Returns 0 if successful, or a negative error code on failure.
 */
int snd_ctl_remove_id(struct snd_card *card, struct snd_ctl_elem_id *id)
{
	struct snd_kcontrol *kctl;
	int ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	ret = snd_ctl_remove(card, kctl);
	up_write(&card->controls_rwsem);
	return ret;
}

EXPORT_SYMBOL(snd_ctl_remove_id);

/**
 * snd_ctl_remove_unlocked_id - remove the unlocked control of the given id and release it
 * @file: active control handle
 * @id: the control id to remove
 *
 * Finds the control instance with the given id, removes it from the
 * card list and releases it.
 * 
 * Returns 0 if successful, or a negative error code on failure.
 */
static int snd_ctl_remove_unlocked_id(struct snd_ctl_file * file,
				      struct snd_ctl_elem_id *id)
{
	struct snd_card *card = file->card;
	struct snd_kcontrol *kctl;
	int idx, ret;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	for (idx = 0; idx < kctl->count; idx++)
		if (kctl->vd[idx].owner != NULL && kctl->vd[idx].owner != file) {
			up_write(&card->controls_rwsem);
			return -EBUSY;
		}
	ret = snd_ctl_remove(card, kctl);
	up_write(&card->controls_rwsem);
	return ret;
}

/**
 * snd_ctl_rename_id - replace the id of a control on the card
 * @card: the card instance
 * @src_id: the old id
 * @dst_id: the new id
 *
 * Finds the control with the old id from the card, and replaces the
 * id with the new one.
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id,
		      struct snd_ctl_elem_id *dst_id)
{
	struct snd_kcontrol *kctl;

	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, src_id);
	if (kctl == NULL) {
		up_write(&card->controls_rwsem);
		return -ENOENT;
	}
	kctl->id = *dst_id;
	kctl->id.numid = card->last_numid + 1;
	card->last_numid += kctl->count;
	up_write(&card->controls_rwsem);
	return 0;
}

EXPORT_SYMBOL(snd_ctl_rename_id);

/**
 * snd_ctl_find_numid - find the control instance with the given number-id
 * @card: the card instance
 * @numid: the number-id to search
 *
 * Finds the control instance with the given number-id from the card.
 *
 * Returns the pointer of the instance if found, or NULL if not.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
 */
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card *card, unsigned int numid)
{
	struct list_head *list;
	struct snd_kcontrol *kctl;

	snd_assert(card != NULL && numid != 0, return NULL);
	list_for_each(list, &card->controls) {
		kctl = snd_kcontrol(list);
		if (kctl->id.numid <= numid && kctl->id.numid + kctl->count > numid)
			return kctl;
	}
	return NULL;
}

EXPORT_SYMBOL(snd_ctl_find_numid);

/**
 * snd_ctl_find_id - find the control instance with the given id
 * @card: the card instance
 * @id: the id to search
 *
 * Finds the control instance with the given id from the card.
 *
 * Returns the pointer of the instance if found, or NULL if not.
 *
 * The caller must down card->controls_rwsem before calling this function
 * (if the race condition can happen).
 */
struct snd_kcontrol *snd_ctl_find_id(struct snd_card *card,
				     struct snd_ctl_elem_id *id)
{
	struct list_head *list;
	struct snd_kcontrol *kctl;

	snd_assert(card != NULL && id != NULL, return NULL);
	if (id->numid != 0)
		return snd_ctl_find_numid(card, id->numid);
	list_for_each(list, &card->controls) {
		kctl = snd_kcontrol(list);
		if (kctl->id.iface != id->iface)
			continue;
		if (kctl->id.device != id->device)
			continue;
		if (kctl->id.subdevice != id->subdevice)
			continue;
		if (strncmp(kctl->id.name, id->name, sizeof(kctl->id.name)))
			continue;
		if (kctl->id.index > id->index)
			continue;
		if (kctl->id.index + kctl->count <= id->index)
			continue;
		return kctl;
	}
	return NULL;
}

EXPORT_SYMBOL(snd_ctl_find_id);

static int snd_ctl_card_info(struct snd_card *card, struct snd_ctl_file * ctl,
			     unsigned int cmd, void __user *arg)
{
	struct snd_ctl_card_info *info;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (! info)
		return -ENOMEM;
	down_read(&snd_ioctl_rwsem);
	info->card = card->number;
	strlcpy(info->id, card->id, sizeof(info->id));
	strlcpy(info->driver, card->driver, sizeof(info->driver));
	strlcpy(info->name, card->shortname, sizeof(info->name));
	strlcpy(info->longname, card->longname, sizeof(info->longname));
	strlcpy(info->mixername, card->mixername, sizeof(info->mixername));
	strlcpy(info->components, card->components, sizeof(info->components));
	up_read(&snd_ioctl_rwsem);
	if (copy_to_user(arg, info, sizeof(struct snd_ctl_card_info))) {
		kfree(info);
		return -EFAULT;
	}
	kfree(info);
	return 0;
}

static int snd_ctl_elem_list(struct snd_card *card,
			     struct snd_ctl_elem_list __user *_list)
{
	struct list_head *plist;
	struct snd_ctl_elem_list list;
	struct snd_kcontrol *kctl;
	struct snd_ctl_elem_id *dst, *id;
	unsigned int offset, space, first, jidx;
	
	if (copy_from_user(&list, _list, sizeof(list)))
		return -EFAULT;
	offset = list.offset;
	space = list.space;
	first = 0;
	/* try limit maximum space */
	if (space > 16384)
		return -ENOMEM;
	if (space > 0) {
		/* allocate temporary buffer for atomic operation */
		dst = vmalloc(space * sizeof(struct snd_ctl_elem_id));
		if (dst == NULL)
			return -ENOMEM;
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		plist = card->controls.next;
		while (plist != &card->controls) {
			if (offset == 0)
				break;
			kctl = snd_kcontrol(plist);
			if (offset < kctl->count)
				break;
			offset -= kctl->count;
			plist = plist->next;
		}
		list.used = 0;
		id = dst;
		while (space > 0 && plist != &card->controls) {
			kctl = snd_kcontrol(plist);
			for (jidx = offset; space > 0 && jidx < kctl->count; jidx++) {
				snd_ctl_build_ioff(id, kctl, jidx);
				id++;
				space--;
				list.used++;
			}
			plist = plist->next;
			offset = 0;
		}
		up_read(&card->controls_rwsem);
		if (list.used > 0 &&
		    copy_to_user(list.pids, dst,
				 list.used * sizeof(struct snd_ctl_elem_id))) {
			vfree(dst);
			return -EFAULT;
		}
		vfree(dst);
	} else {
		down_read(&card->controls_rwsem);
		list.count = card->controls_count;
		up_read(&card->controls_rwsem);
	}
	if (copy_to_user(_list, &list, sizeof(list)))
		return -EFAULT;
	return 0;
}

static int snd_ctl_elem_info(struct snd_ctl_file *ctl,
			     struct snd_ctl_elem_info *info)
{
	struct snd_card *card = ctl->card;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int result;
	
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &info->id);
	if (kctl == NULL) {
		up_read(&card->controls_rwsem);
		return -ENOENT;
	}
#ifdef CONFIG_SND_DEBUG
	info->access = 0;
#endif
	result = kctl->info(kctl, info);
	if (result >= 0) {
		snd_assert(info->access == 0, );
		index_offset = snd_ctl_get_ioff(kctl, &info->id);
		vd = &kctl->vd[index_offset];
		snd_ctl_build_ioff(&info->id, kctl, index_offset);
		info->access = vd->access;
		if (vd->owner) {
			info->access |= SNDRV_CTL_ELEM_ACCESS_LOCK;
			if (vd->owner == ctl)
				info->access |= SNDRV_CTL_ELEM_ACCESS_OWNER;
			info->owner = vd->owner_pid;
		} else {
			info->owner = -1;
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

static int snd_ctl_elem_info_user(struct snd_ctl_file *ctl,
				  struct snd_ctl_elem_info __user *_info)
{
	struct snd_ctl_elem_info info;
	int result;

	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
	snd_power_lock(ctl->card);
	result = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
	if (result >= 0)
		result = snd_ctl_elem_info(ctl, &info);
	snd_power_unlock(ctl->card);
	if (result >= 0)
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
	return result;
}

int snd_ctl_elem_read(struct snd_card *card, struct snd_ctl_elem_value *control)
{
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int result, indirect;

	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
		if (control->indirect != indirect) {
			result = -EACCES;
		} else {
			if ((vd->access & SNDRV_CTL_ELEM_ACCESS_READ) && kctl->get != NULL) {
				snd_ctl_build_ioff(&control->id, kctl, index_offset);
				result = kctl->get(kctl, control);
			} else {
				result = -EPERM;
			}
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

EXPORT_SYMBOL(snd_ctl_elem_read);

static int snd_ctl_elem_read_user(struct snd_card *card,
				  struct snd_ctl_elem_value __user *_control)
{
	struct snd_ctl_elem_value *control;
	int result;
	
	control = kmalloc(sizeof(*control), GFP_KERNEL);
	if (control == NULL)
		return -ENOMEM;	
	if (copy_from_user(control, _control, sizeof(*control))) {
		kfree(control);
		return -EFAULT;
	}
	snd_power_lock(card);
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
	if (result >= 0)
		result = snd_ctl_elem_read(card, control);
	snd_power_unlock(card);
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
		       struct snd_ctl_elem_value *control)
{
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int index_offset;
	int result, indirect;

	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &control->id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		index_offset = snd_ctl_get_ioff(kctl, &control->id);
		vd = &kctl->vd[index_offset];
		indirect = vd->access & SNDRV_CTL_ELEM_ACCESS_INDIRECT ? 1 : 0;
		if (control->indirect != indirect) {
			result = -EACCES;
		} else {
			if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) ||
			    kctl->put == NULL ||
			    (file && vd->owner != NULL && vd->owner != file)) {
				result = -EPERM;
			} else {
				snd_ctl_build_ioff(&control->id, kctl, index_offset);
				result = kctl->put(kctl, control);
			}
			if (result > 0) {
				up_read(&card->controls_rwsem);
				snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &control->id);
				return 0;
			}
		}
	}
	up_read(&card->controls_rwsem);
	return result;
}

EXPORT_SYMBOL(snd_ctl_elem_write);

static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
				   struct snd_ctl_elem_value __user *_control)
{
	struct snd_ctl_elem_value *control;
	struct snd_card *card;
	int result;

	control = kmalloc(sizeof(*control), GFP_KERNEL);
	if (control == NULL)
		return -ENOMEM;	
	if (copy_from_user(control, _control, sizeof(*control))) {
		kfree(control);
		return -EFAULT;
	}
	card = file->card;
	snd_power_lock(card);
	result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
	if (result >= 0)
		result = snd_ctl_elem_write(card, file, control);
	snd_power_unlock(card);
	if (result >= 0)
		if (copy_to_user(_control, control, sizeof(*control)))
			result = -EFAULT;
	kfree(control);
	return result;
}

static int snd_ctl_elem_lock(struct snd_ctl_file *file,
			     struct snd_ctl_elem_id __user *_id)
{
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner != NULL)
			result = -EBUSY;
		else {
			vd->owner = file;
			vd->owner_pid = current->pid;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

static int snd_ctl_elem_unlock(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
{
	struct snd_card *card = file->card;
	struct snd_ctl_elem_id id;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	int result;
	
	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	down_write(&card->controls_rwsem);
	kctl = snd_ctl_find_id(card, &id);
	if (kctl == NULL) {
		result = -ENOENT;
	} else {
		vd = &kctl->vd[snd_ctl_get_ioff(kctl, &id)];
		if (vd->owner == NULL)
			result = -EINVAL;
		else if (vd->owner != file)
			result = -EPERM;
		else {
			vd->owner = NULL;
			vd->owner_pid = 0;
			result = 0;
		}
	}
	up_write(&card->controls_rwsem);
	return result;
}

struct user_element {
	struct snd_ctl_elem_info info;
	void *elem_data;		/* element data */
	unsigned long elem_data_size;	/* size of element data in bytes */
	void *tlv_data;			/* TLV data */
	unsigned long tlv_data_size;	/* TLV data size */
	void *priv_data;		/* private data (like strings for enumerated type) */
	unsigned long priv_data_size;	/* size of private data in bytes */
};

static int snd_ctl_elem_user_info(struct snd_kcontrol *kcontrol,
				  struct snd_ctl_elem_info *uinfo)
{
	struct user_element *ue = kcontrol->private_data;

	*uinfo = ue->info;
	return 0;
}

static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
{
	struct user_element *ue = kcontrol->private_data;

	memcpy(&ucontrol->value, ue->elem_data, ue->elem_data_size);
	return 0;
}

static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol,
				 struct snd_ctl_elem_value *ucontrol)
{
	int change;
	struct user_element *ue = kcontrol->private_data;
	
	change = memcmp(&ucontrol->value, ue->elem_data, ue->elem_data_size) != 0;
	if (change)
		memcpy(ue->elem_data, &ucontrol->value, ue->elem_data_size);
	return change;
}

static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
				 int op_flag,
				 unsigned int size,
				 unsigned int __user *tlv)
{
	struct user_element *ue = kcontrol->private_data;
	int change = 0;
	void *new_data;

	if (op_flag > 0) {
		if (size > 1024 * 128)	/* sane value */
			return -EINVAL;
		new_data = kmalloc(size, GFP_KERNEL);
		if (new_data == NULL)
			return -ENOMEM;
		if (copy_from_user(new_data, tlv, size)) {
			kfree(new_data);
			return -EFAULT;
		}
		change = ue->tlv_data_size != size;
		if (!change)
			change = memcmp(ue->tlv_data, new_data, size);
		kfree(ue->tlv_data);
		ue->tlv_data = new_data;
		ue->tlv_data_size = size;
	} else {
		if (! ue->tlv_data_size || ! ue->tlv_data)
			return -ENXIO;
		if (size < ue->tlv_data_size)
			return -ENOSPC;
		if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size))
			return -EFAULT;
	}
	return change;
}

static void snd_ctl_elem_user_free(struct snd_kcontrol *kcontrol)
{
	struct user_element *ue = kcontrol->private_data;
	if (ue->tlv_data)
		kfree(ue->tlv_data);
	kfree(ue);
}

static int snd_ctl_elem_add(struct snd_ctl_file *file,
			    struct snd_ctl_elem_info *info, int replace)
{
	struct snd_card *card = file->card;
	struct snd_kcontrol kctl, *_kctl;
	unsigned int access;
	long private_size;
	struct user_element *ue;
	int idx, err;
	
	if (card->user_ctl_count >= MAX_USER_CONTROLS)
		return -ENOMEM;
	if (info->count > 1024)
		return -EINVAL;
	access = info->access == 0 ? SNDRV_CTL_ELEM_ACCESS_READWRITE :
		(info->access & (SNDRV_CTL_ELEM_ACCESS_READWRITE|
				 SNDRV_CTL_ELEM_ACCESS_INACTIVE|
				 SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE));
	info->id.numid = 0;
	memset(&kctl, 0, sizeof(kctl));
	down_write(&card->controls_rwsem);
	_kctl = snd_ctl_find_id(card, &info->id);
	err = 0;
	if (_kctl) {
		if (replace)
			err = snd_ctl_remove(card, _kctl);
		else
			err = -EBUSY;
	} else {
		if (replace)
			err = -ENOENT;
	}
	up_write(&card->controls_rwsem);
	if (err < 0)
		return err;
	memcpy(&kctl.id, &info->id, sizeof(info->id));
	kctl.count = info->owner ? info->owner : 1;
	access |= SNDRV_CTL_ELEM_ACCESS_USER;
	kctl.info = snd_ctl_elem_user_info;
	if (access & SNDRV_CTL_ELEM_ACCESS_READ)
		kctl.get = snd_ctl_elem_user_get;
	if (access & SNDRV_CTL_ELEM_ACCESS_WRITE)
		kctl.put = snd_ctl_elem_user_put;
	if (access & SNDRV_CTL_ELEM_ACCESS_TLV_READWRITE) {
		kctl.tlv.c = snd_ctl_elem_user_tlv;
		access |= SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
	}
	switch (info->type) {
	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
	case SNDRV_CTL_ELEM_TYPE_INTEGER:
		private_size = sizeof(long);
		if (info->count > 128)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
		private_size = sizeof(long long);
		if (info->count > 64)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_BYTES:
		private_size = sizeof(unsigned char);
		if (info->count > 512)
			return -EINVAL;
		break;
	case SNDRV_CTL_ELEM_TYPE_IEC958:
		private_size = sizeof(struct snd_aes_iec958);
		if (info->count != 1)
			return -EINVAL;
		break;
	default:
		return -EINVAL;
	}
	private_size *= info->count;
	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
	if (ue == NULL)
		return -ENOMEM;
	ue->info = *info;
	ue->info.access = 0;
	ue->elem_data = (char *)ue + sizeof(*ue);
	ue->elem_data_size = private_size;
	kctl.private_free = snd_ctl_elem_user_free;
	_kctl = snd_ctl_new(&kctl, access);
	if (_kctl == NULL) {
		kfree(ue);
		return -ENOMEM;
	}
	_kctl->private_data = ue;
	for (idx = 0; idx < _kctl->count; idx++)
		_kctl->vd[idx].owner = file;
	err = snd_ctl_add(card, _kctl);
	if (err < 0)
		return err;

	down_write(&card->controls_rwsem);
	card->user_ctl_count++;
	up_write(&card->controls_rwsem);

	return 0;
}

static int snd_ctl_elem_add_user(struct snd_ctl_file *file,
				 struct snd_ctl_elem_info __user *_info, int replace)
{
	struct snd_ctl_elem_info info;
	if (copy_from_user(&info, _info, sizeof(info)))
		return -EFAULT;
	return snd_ctl_elem_add(file, &info, replace);
}

static int snd_ctl_elem_remove(struct snd_ctl_file *file,
			       struct snd_ctl_elem_id __user *_id)
{
	struct snd_ctl_elem_id id;
	int err;

	if (copy_from_user(&id, _id, sizeof(id)))
		return -EFAULT;
	err = snd_ctl_remove_unlocked_id(file, &id);
	if (! err) {
		struct snd_card *card = file->card;
		down_write(&card->controls_rwsem);
		card->user_ctl_count--;
		up_write(&card->controls_rwsem);
	}
	return err;
}

static int snd_ctl_subscribe_events(struct snd_ctl_file *file, int __user *ptr)
{
	int subscribe;
	if (get_user(subscribe, ptr))
		return -EFAULT;
	if (subscribe < 0) {
		subscribe = file->subscribed;
		if (put_user(subscribe, ptr))
			return -EFAULT;
		return 0;
	}
	if (subscribe) {
		file->subscribed = 1;
		return 0;
	} else if (file->subscribed) {
		snd_ctl_empty_read_queue(file);
		file->subscribed = 0;
	}
	return 0;
}

static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
                             struct snd_ctl_tlv __user *_tlv,
                             int op_flag)
{
	struct snd_card *card = file->card;
	struct snd_ctl_tlv tlv;
	struct snd_kcontrol *kctl;
	struct snd_kcontrol_volatile *vd;
	unsigned int len;
	int err = 0;

	if (copy_from_user(&tlv, _tlv, sizeof(tlv)))
		return -EFAULT;
	if (tlv.length < sizeof(unsigned int) * 3)
		return -EINVAL;
	down_read(&card->controls_rwsem);
	kctl = snd_ctl_find_numid(card, tlv.numid);
	if (kctl == NULL) {
		err = -ENOENT;
		goto __kctl_end;
	}
	if (kctl->tlv.p == NULL) {
		err = -ENXIO;
		goto __kctl_end;
	}
	vd = &kctl->vd[tlv.numid - kctl->id.numid];
	if ((op_flag == 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_READ) == 0) ||
	    (op_flag > 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_WRITE) == 0) ||
	    (op_flag < 0 && (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_COMMAND) == 0)) {
	    	err = -ENXIO;
	    	goto __kctl_end;
	}
	if (vd->access & SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK) {
		if (file && vd->owner != NULL && vd->owner != file) {
			err = -EPERM;
			goto __kctl_end;
		}
		err = kctl->tlv.c(kctl, op_flag, tlv.length, _tlv->tlv); 
		if (err > 0) {
			up_read(&card->controls_rwsem);
			snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_TLV, &kctl->id);
			return 0;
		}
	} else {
		if (op_flag) {
			err = -ENXIO;
			goto __kctl_end;
		}
		len = kctl->tlv.p[1] + 2 * sizeof(unsigned int);
		if (tlv.length < len) {
			err = -ENOMEM;
			goto __kctl_end;
		}
		if (copy_to_user(_tlv->tlv, kctl->tlv.p, len))
			err = -EFAULT;
	}
      __kctl_end:
	up_read(&card->controls_rwsem);
	return err;
}

static long snd_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct snd_ctl_file *ctl;
	struct snd_card *card;
	struct list_head *list;
	struct snd_kctl_ioctl *p;
	void __user *argp = (void __user *)arg;
	int __user *ip = argp;
	int err;

	ctl = file->private_data;
	card = ctl->card;
	snd_assert(card != NULL, return -ENXIO);
	switch (cmd) {
	case SNDRV_CTL_IOCTL_PVERSION:
		return put_user(SNDRV_CTL_VERSION, ip) ? -EFAULT : 0;
	case SNDRV_CTL_IOCTL_CARD_INFO:
		return snd_ctl_card_info(card, ctl, cmd, argp);
	case SNDRV_CTL_IOCTL_ELEM_LIST:
		return snd_ctl_elem_list(card, argp);
	case SNDRV_CTL_IOCTL_ELEM_INFO:
		return snd_ctl_elem_info_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_READ:
		return snd_ctl_elem_read_user(card, argp);
	case SNDRV_CTL_IOCTL_ELEM_WRITE:
		return snd_ctl_elem_write_user(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_LOCK:
		return snd_ctl_elem_lock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
		return snd_ctl_elem_unlock(ctl, argp);
	case SNDRV_CTL_IOCTL_ELEM_ADD:
		return snd_ctl_elem_add_user(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_ELEM_REPLACE:
		return snd_ctl_elem_add_user(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_ELEM_REMOVE:
		return snd_ctl_elem_remove(ctl, argp);
	case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
		return snd_ctl_subscribe_events(ctl, ip);
	case SNDRV_CTL_IOCTL_TLV_READ:
		return snd_ctl_tlv_ioctl(ctl, argp, 0);
	case SNDRV_CTL_IOCTL_TLV_WRITE:
		return snd_ctl_tlv_ioctl(ctl, argp, 1);
	case SNDRV_CTL_IOCTL_TLV_COMMAND:
		return snd_ctl_tlv_ioctl(ctl, argp, -1);
	case SNDRV_CTL_IOCTL_POWER:
		return -ENOPROTOOPT;
	case SNDRV_CTL_IOCTL_POWER_STATE:
#ifdef CONFIG_PM
		return put_user(card->power_state, ip) ? -EFAULT : 0;
#else
		return put_user(SNDRV_CTL_POWER_D0, ip) ? -EFAULT : 0;
#endif
	}
	down_read(&snd_ioctl_rwsem);
	list_for_each(list, &snd_control_ioctls) {
		p = list_entry(list, struct snd_kctl_ioctl, list);
		err = p->fioctl(card, ctl, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			up_read(&snd_ioctl_rwsem);
			return err;
		}
	}
	up_read(&snd_ioctl_rwsem);
	snd_printdd("unknown ioctl = 0x%x\n", cmd);
	return -ENOTTY;
}

static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
			    size_t count, loff_t * offset)
{
	struct snd_ctl_file *ctl;
	int err = 0;
	ssize_t result = 0;

	ctl = file->private_data;
	snd_assert(ctl != NULL && ctl->card != NULL, return -ENXIO);
	if (!ctl->subscribed)
		return -EBADFD;
	if (count < sizeof(struct snd_ctl_event))
		return -EINVAL;
	spin_lock_irq(&ctl->read_lock);
	while (count >= sizeof(struct snd_ctl_event)) {
		struct snd_ctl_event ev;
		struct snd_kctl_event *kev;
		while (list_empty(&ctl->events)) {
			wait_queue_t wait;
			if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
				err = -EAGAIN;
				goto __end_lock;
			}
			init_waitqueue_entry(&wait, current);
			add_wait_queue(&ctl->change_sleep, &wait);
			set_current_state(TASK_INTERRUPTIBLE);
			spin_unlock_irq(&ctl->read_lock);
			schedule();
			remove_wait_queue(&ctl->change_sleep, &wait);
			if (signal_pending(current))
				return result > 0 ? result : -ERESTARTSYS;
			spin_lock_irq(&ctl->read_lock);
		}
		kev = snd_kctl_event(ctl->events.next);
		ev.type = SNDRV_CTL_EVENT_ELEM;
		ev.data.elem.mask = kev->mask;
		ev.data.elem.id = kev->id;
		list_del(&kev->list);
		spin_unlock_irq(&ctl->read_lock);
		kfree(kev);
		if (copy_to_user(buffer, &ev, sizeof(struct snd_ctl_event))) {
			err = -EFAULT;
			goto __end;
		}
		spin_lock_irq(&ctl->read_lock);
		buffer += sizeof(struct snd_ctl_event);
		count -= sizeof(struct snd_ctl_event);
		result += sizeof(struct snd_ctl_event);
	}
      __end_lock:
	spin_unlock_irq(&ctl->read_lock);
      __end:
      	return result > 0 ? result : err;
}

static unsigned int snd_ctl_poll(struct file *file, poll_table * wait)
{
	unsigned int mask;
	struct snd_ctl_file *ctl;

	ctl = file->private_data;
	if (!ctl->subscribed)
		return 0;
	poll_wait(file, &ctl->change_sleep, wait);

	mask = 0;
	if (!list_empty(&ctl->events))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

/*
 * register the device-specific control-ioctls.
 * called from each device manager like pcm.c, hwdep.c, etc.
 */
static int _snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn, struct list_head *lists)
{
	struct snd_kctl_ioctl *pn;

	pn = kzalloc(sizeof(struct snd_kctl_ioctl), GFP_KERNEL);
	if (pn == NULL)
		return -ENOMEM;
	pn->fioctl = fcn;
	down_write(&snd_ioctl_rwsem);
	list_add_tail(&pn->list, lists);
	up_write(&snd_ioctl_rwsem);
	return 0;
}

int snd_ctl_register_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_ioctls);
}

EXPORT_SYMBOL(snd_ctl_register_ioctl);

#ifdef CONFIG_COMPAT
int snd_ctl_register_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_register_ioctl(fcn, &snd_control_compat_ioctls);
}

EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
#endif

/*
 * de-register the device-specific control-ioctls.
 */
static int _snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn,
				     struct list_head *lists)
{
	struct list_head *list;
	struct snd_kctl_ioctl *p;

	snd_assert(fcn != NULL, return -EINVAL);
	down_write(&snd_ioctl_rwsem);
	list_for_each(list, lists) {
		p = list_entry(list, struct snd_kctl_ioctl, list);
		if (p->fioctl == fcn) {
			list_del(&p->list);
			up_write(&snd_ioctl_rwsem);
			kfree(p);
			return 0;
		}
	}
	up_write(&snd_ioctl_rwsem);
	snd_BUG();
	return -EINVAL;
}

int snd_ctl_unregister_ioctl(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_ioctls);
}

EXPORT_SYMBOL(snd_ctl_unregister_ioctl);

#ifdef CONFIG_COMPAT
int snd_ctl_unregister_ioctl_compat(snd_kctl_ioctl_func_t fcn)
{
	return _snd_ctl_unregister_ioctl(fcn, &snd_control_compat_ioctls);
}

EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
#endif

static int snd_ctl_fasync(int fd, struct file * file, int on)
{
	struct snd_ctl_file *ctl;
	int err;
	ctl = file->private_data;
	err = fasync_helper(fd, file, on, &ctl->fasync);
	if (err < 0)
		return err;
	return 0;
}

/*
 * ioctl32 compat
 */
#ifdef CONFIG_COMPAT
#include "control_compat.c"
#else
#define snd_ctl_ioctl_compat	NULL
#endif

/*
 *  INIT PART
 */

static struct file_operations snd_ctl_f_ops =
{
	.owner =	THIS_MODULE,
	.read =		snd_ctl_read,
	.open =		snd_ctl_open,
	.release =	snd_ctl_release,
	.poll =		snd_ctl_poll,
	.unlocked_ioctl =	snd_ctl_ioctl,
	.compat_ioctl =	snd_ctl_ioctl_compat,
	.fasync =	snd_ctl_fasync,
};

/*
 * registration of the control device
 */
static int snd_ctl_dev_register(struct snd_device *device)
{
	struct snd_card *card = device->device_data;
	int err, cardnum;
	char name[16];

	snd_assert(card != NULL, return -ENXIO);
	cardnum = card->number;
	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);
	sprintf(name, "controlC%i", cardnum);
	if ((err = snd_register_device(SNDRV_DEVICE_TYPE_CONTROL, card, -1,
				       &snd_ctl_f_ops, card, name)) < 0)
		return err;
	return 0;
}

/*
 * disconnection of the control device
 */
static int snd_ctl_dev_disconnect(struct snd_device *device)
{
	struct snd_card *card = device->device_data;
	struct list_head *flist;
	struct snd_ctl_file *ctl;
	int err, cardnum;

	snd_assert(card != NULL, return -ENXIO);
	cardnum = card->number;
	snd_assert(cardnum >= 0 && cardnum < SNDRV_CARDS, return -ENXIO);

	down_read(&card->controls_rwsem);
	list_for_each(flist, &card->ctl_files) {
		ctl = snd_ctl_file(flist);
		wake_up(&ctl->change_sleep);
		kill_fasync(&ctl->fasync, SIGIO, POLL_ERR);
	}
	up_read(&card->controls_rwsem);

	if ((err = snd_unregister_device(SNDRV_DEVICE_TYPE_CONTROL,
					 card, -1)) < 0)
		return err;
	return 0;
}

/*
 * free all controls
 */
static int snd_ctl_dev_free(struct snd_device *device)
{
	struct snd_card *card = device->device_data;
	struct snd_kcontrol *control;

	down_write(&card->controls_rwsem);
	while (!list_empty(&card->controls)) {
		control = snd_kcontrol(card->controls.next);
		snd_ctl_remove(card, control);
	}
	up_write(&card->controls_rwsem);
	return 0;
}

/*
 * create control core:
 * called from init.c
 */
int snd_ctl_create(struct snd_card *card)
{
	static struct snd_device_ops ops = {
		.dev_free = snd_ctl_dev_free,
		.dev_register =	snd_ctl_dev_register,
		.dev_disconnect = snd_ctl_dev_disconnect,
	};

	snd_assert(card != NULL, return -ENXIO);
	return snd_device_new(card, SNDRV_DEV_CONTROL, card, &ops);
}
OpenPOWER on IntegriCloud