summaryrefslogtreecommitdiffstats
path: root/drivers/isdn/mISDN/dsp_core.c
blob: 2ac2d7a25a9f53103eb4d95b5e919aaa4067fd1b (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
/*
 * Author       Andreas Eversberg (jolly@eversberg.eu)
 * Based on source code structure by
 *		Karsten Keil (keil@isdn4linux.de)
 *
 *		This file is (c) under GNU PUBLIC LICENSE
 *		For changes and modifications please read
 *		../../../Documentation/isdn/mISDN.cert
 *
 * Thanks to    Karsten Keil (great drivers)
 *              Cologne Chip (great chips)
 *
 * This module does:
 *		Real-time tone generation
 *		DTMF detection
 *		Real-time cross-connection and conferrence
 *		Compensate jitter due to system load and hardware fault.
 *		All features are done in kernel space and will be realized
 *		using hardware, if available and supported by chip set.
 *		Blowfish encryption/decryption
 */

/* STRUCTURE:
 *
 * The dsp module provides layer 2 for b-channels (64kbit). It provides
 * transparent audio forwarding with special digital signal processing:
 *
 * - (1) generation of tones
 * - (2) detection of dtmf tones
 * - (3) crossconnecting and conferences (clocking)
 * - (4) echo generation for delay test
 * - (5) volume control
 * - (6) disable receive data
 * - (7) pipeline
 * - (8) encryption/decryption
 *
 * Look:
 *             TX            RX
 *         ------upper layer------
 *             |             ^
 *             |             |(6)
 *             v             |
 *       +-----+-------------+-----+
 *       |(3)(4)                   |
 *       |           CMX           |
 *       |                         |
 *       |           +-------------+
 *       |           |       ^
 *       |           |       |
 *       |+---------+|  +----+----+
 *       ||(1)      ||  |(2)      |
 *       ||         ||  |         |
 *       ||  Tones  ||  |  DTMF   |
 *       ||         ||  |         |
 *       ||         ||  |         |
 *       |+----+----+|  +----+----+
 *       +-----+-----+       ^
 *             |             |
 *             v             |
 *        +----+----+   +----+----+
 *        |(5)      |   |(5)      |
 *        |         |   |         |
 *        |TX Volume|   |RX Volume|
 *        |         |   |         |
 *        |         |   |         |
 *        +----+----+   +----+----+
 *             |             ^
 *             |             |
 *             v             |
 *        +----+-------------+----+
 *        |(7)                    |
 *        |                       |
 *        |  Pipeline Processing  |
 *        |                       |
 *        |                       |
 *        +----+-------------+----+
 *             |             ^
 *             |             |
 *             v             |
 *        +----+----+   +----+----+
 *        |(8)      |   |(8)      |
 *        |         |   |         |
 *        | Encrypt |   | Decrypt |
 *        |         |   |         |
 *        |         |   |         |
 *        +----+----+   +----+----+
 *             |             ^
 *             |             |
 *             v             |
 *         ------card  layer------
 *             TX            RX
 *
 * Above you can see the logical data flow. If software is used to do the
 * process, it is actually the real data flow. If hardware is used, data
 * may not flow, but hardware commands to the card, to provide the data flow
 * as shown.
 *
 * NOTE: The channel must be activated in order to make dsp work, even if
 * no data flow to the upper layer is intended. Activation can be done
 * after and before controlling the setting using PH_CONTROL requests.
 *
 * DTMF: Will be detected by hardware if possible. It is done before CMX
 * processing.
 *
 * Tones: Will be generated via software if endless looped audio fifos are
 * not supported by hardware. Tones will override all data from CMX.
 * It is not required to join a conference to use tones at any time.
 *
 * CMX: Is transparent when not used. When it is used, it will do
 * crossconnections and conferences via software if not possible through
 * hardware. If hardware capability is available, hardware is used.
 *
 * Echo: Is generated by CMX and is used to check performance of hard and
 * software CMX.
 *
 * The CMX has special functions for conferences with one, two and more
 * members. It will allow different types of data flow. Receive and transmit
 * data to/form upper layer may be swithed on/off individually without losing
 * features of CMX, Tones and DTMF.
 *
 * Echo Cancellation: Sometimes we like to cancel echo from the interface.
 * Note that a VoIP call may not have echo caused by the IP phone. The echo
 * is generated by the telephone line connected to it. Because the delay
 * is high, it becomes an echo. RESULT: Echo Cachelation is required if
 * both echo AND delay is applied to an interface.
 * Remember that software CMX always generates a more or less delay.
 *
 * If all used features can be realized in hardware, and if transmit and/or
 * receive data ist disabled, the card may not send/receive any data at all.
 * Not receiving is useful if only announcements are played. Not sending is
 * useful if an answering machine records audio. Not sending and receiving is
 * useful during most states of the call. If supported by hardware, tones
 * will be played without cpu load. Small PBXs and NT-Mode applications will
 * not need expensive hardware when processing calls.
 *
 *
 * LOCKING:
 *
 * When data is received from upper or lower layer (card), the complete dsp
 * module is locked by a global lock.  This lock MUST lock irq, because it
 * must lock timer events by DSP poll timer.
 * When data is ready to be transmitted down, the data is queued and sent
 * outside lock and timer event.
 * PH_CONTROL must not change any settings, join or split conference members
 * during process of data.
 *
 * HDLC:
 *
 * It works quite the same as transparent, except that HDLC data is forwarded
 * to all other conference members if no hardware bridging is possible.
 * Send data will be writte to sendq. Sendq will be sent if confirm is received.
 * Conference cannot join, if one member is not hdlc.
 *
 */

#include <linux/delay.h>
#include <linux/gfp.h>
#include <linux/mISDNif.h>
#include <linux/mISDNdsp.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include "core.h"
#include "dsp.h"

static const char *mISDN_dsp_revision = "2.0";

static int debug;
static int options;
static int poll;
static int dtmfthreshold = 100;

MODULE_AUTHOR("Andreas Eversberg");
module_param(debug, uint, S_IRUGO | S_IWUSR);
module_param(options, uint, S_IRUGO | S_IWUSR);
module_param(poll, uint, S_IRUGO | S_IWUSR);
module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
MODULE_LICENSE("GPL");

/*int spinnest = 0;*/

spinlock_t dsp_lock; /* global dsp lock */
struct list_head dsp_ilist;
struct list_head conf_ilist;
int dsp_debug;
int dsp_options;
int dsp_poll, dsp_tics;

/* check if rx may be turned off or must be turned on */
static void
dsp_rx_off_member(struct dsp *dsp)
{
	struct mISDN_ctrl_req	cq;
	int rx_off = 1;

	memset(&cq, 0, sizeof(cq));

	if (!dsp->features_rx_off)
		return;

	/* not disabled */
	if (!dsp->rx_disabled)
		rx_off = 0;
	/* software dtmf */
	else if (dsp->dtmf.software)
		rx_off = 0;
	/* echo in software */
	else if (dsp->echo.software)
		rx_off = 0;
	/* bridge in software */
	else if (dsp->conf && dsp->conf->software)
		rx_off = 0;
	/* data is not required by user space and not required
	 * for echo dtmf detection, soft-echo, soft-bridging */

	if (rx_off == dsp->rx_is_off)
		return;

	if (!dsp->ch.peer) {
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: no peer, no rx_off\n",
			       __func__);
		return;
	}
	cq.op = MISDN_CTRL_RX_OFF;
	cq.p1 = rx_off;
	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
		printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
		       __func__);
		return;
	}
	dsp->rx_is_off = rx_off;
	if (dsp_debug & DEBUG_DSP_CORE)
		printk(KERN_DEBUG "%s: %s set rx_off = %d\n",
		       __func__, dsp->name, rx_off);
}
static void
dsp_rx_off(struct dsp *dsp)
{
	struct dsp_conf_member	*member;

	if (dsp_options & DSP_OPT_NOHARDWARE)
		return;

	/* no conf */
	if (!dsp->conf) {
		dsp_rx_off_member(dsp);
		return;
	}
	/* check all members in conf */
	list_for_each_entry(member, &dsp->conf->mlist, list) {
		dsp_rx_off_member(member->dsp);
	}
}

/* enable "fill empty" feature */
static void
dsp_fill_empty(struct dsp *dsp)
{
	struct mISDN_ctrl_req	cq;

	memset(&cq, 0, sizeof(cq));

	if (!dsp->ch.peer) {
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: no peer, no fill_empty\n",
			       __func__);
		return;
	}
	cq.op = MISDN_CTRL_FILL_EMPTY;
	cq.p1 = 1;
	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
		       __func__);
		return;
	}
	if (dsp_debug & DEBUG_DSP_CORE)
		printk(KERN_DEBUG "%s: %s set fill_empty = 1\n",
		       __func__, dsp->name);
}

static int
dsp_control_req(struct dsp *dsp, struct mISDNhead *hh, struct sk_buff *skb)
{
	struct sk_buff	*nskb;
	int ret = 0;
	int cont;
	u8 *data;
	int len;

	if (skb->len < sizeof(int))
		printk(KERN_ERR "%s: PH_CONTROL message too short\n", __func__);
	cont = *((int *)skb->data);
	len = skb->len - sizeof(int);
	data = skb->data + sizeof(int);

	switch (cont) {
	case DTMF_TONE_START: /* turn on DTMF */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: start dtmf\n", __func__);
		if (len == sizeof(int)) {
			if (dsp_debug & DEBUG_DSP_CORE)
				printk(KERN_NOTICE "changing DTMF Threshold "
				       "to %d\n", *((int *)data));
			dsp->dtmf.treshold = (*(int *)data) * 10000;
		}
		dsp->dtmf.enable = 1;
		/* init goertzel */
		dsp_dtmf_goertzel_init(dsp);

		/* check dtmf hardware */
		dsp_dtmf_hardware(dsp);
		dsp_rx_off(dsp);
		break;
	case DTMF_TONE_STOP: /* turn off DTMF */
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
		dsp->dtmf.enable = 0;
		dsp->dtmf.hardware = 0;
		dsp->dtmf.software = 0;
		break;
	case DSP_CONF_JOIN: /* join / update conference */
		if (len < sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		if (*((u32 *)data) == 0)
			goto conf_split;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: join conference %d\n",
			       __func__, *((u32 *)data));
		ret = dsp_cmx_conf(dsp, *((u32 *)data));
		/* dsp_cmx_hardware will also be called here */
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_CONF_SPLIT: /* remove from conference */
	conf_split:
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: release conference\n", __func__);
		ret = dsp_cmx_conf(dsp, 0);
		/* dsp_cmx_hardware will also be called here */
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		dsp_rx_off(dsp);
		break;
	case DSP_TONE_PATT_ON: /* play tone */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len < sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
			       __func__, *((int *)skb->data));
		ret = dsp_tone(dsp, *((int *)data));
		if (!ret) {
			dsp_cmx_hardware(dsp->conf, dsp);
			dsp_rx_off(dsp);
		}
		if (!dsp->tone.tone)
			goto tone_off;
		break;
	case DSP_TONE_PATT_OFF: /* stop tone */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: turn tone off\n", __func__);
		dsp_tone(dsp, 0);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		/* reset tx buffers (user space data) */
	tone_off:
		dsp->rx_W = 0;
		dsp->rx_R = 0;
		break;
	case DSP_VOL_CHANGE_TX: /* change volume */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len < sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		dsp->tx_volume = *((int *)data);
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: change tx vol to %d\n",
			       __func__, dsp->tx_volume);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_dtmf_hardware(dsp);
		dsp_rx_off(dsp);
		break;
	case DSP_VOL_CHANGE_RX: /* change volume */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len < sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		dsp->rx_volume = *((int *)data);
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: change rx vol to %d\n",
			       __func__, dsp->tx_volume);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_dtmf_hardware(dsp);
		dsp_rx_off(dsp);
		break;
	case DSP_ECHO_ON: /* enable echo */
		dsp->echo.software = 1; /* soft echo */
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_ECHO_OFF: /* disable echo */
		dsp->echo.software = 0;
		dsp->echo.hardware = 0;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_RECEIVE_ON: /* enable receive to user space */
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: enable receive to user "
			       "space\n", __func__);
		dsp->rx_disabled = 0;
		dsp_rx_off(dsp);
		break;
	case DSP_RECEIVE_OFF: /* disable receive to user space */
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: disable receive to "
			       "user space\n", __func__);
		dsp->rx_disabled = 1;
		dsp_rx_off(dsp);
		break;
	case DSP_MIX_ON: /* enable mixing of tx data */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: enable mixing of "
			       "tx-data with conf mebers\n", __func__);
		dsp->tx_mix = 1;
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_MIX_OFF: /* disable mixing of tx data */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: disable mixing of "
			       "tx-data with conf mebers\n", __func__);
		dsp->tx_mix = 0;
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_TXDATA_ON: /* enable txdata */
		dsp->tx_data = 1;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_TXDATA_OFF: /* disable txdata */
		dsp->tx_data = 0;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		if (dsp_debug & DEBUG_DSP_CMX)
			dsp_cmx_debug(dsp);
		break;
	case DSP_DELAY: /* use delay algorithm instead of dynamic
			   jitter algorithm */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len < sizeof(int)) {
			ret = -EINVAL;
			break;
		}
		dsp->cmx_delay = (*((int *)data)) << 3;
		/* milliseconds to samples */
		if (dsp->cmx_delay >= (CMX_BUFF_HALF >> 1))
			/* clip to half of maximum usable buffer
			   (half of half buffer) */
			dsp->cmx_delay = (CMX_BUFF_HALF >> 1) - 1;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: use delay algorithm to "
			       "compensate jitter (%d samples)\n",
			       __func__, dsp->cmx_delay);
		break;
	case DSP_JITTER: /* use dynamic jitter algorithm instead of
			    delay algorithm */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		dsp->cmx_delay = 0;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: use jitter algorithm to "
			       "compensate jitter\n", __func__);
		break;
	case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		dsp->tx_dejitter = 1;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: use dejitter on TX "
			       "buffer\n", __func__);
		break;
	case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		dsp->tx_dejitter = 0;
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: use TX buffer without "
			       "dejittering\n", __func__);
		break;
	case DSP_PIPELINE_CFG:
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len > 0 && ((char *)data)[len - 1]) {
			printk(KERN_DEBUG "%s: pipeline config string "
			       "is not NULL terminated!\n", __func__);
			ret = -EINVAL;
		} else {
			dsp->pipeline.inuse = 1;
			dsp_cmx_hardware(dsp->conf, dsp);
			ret = dsp_pipeline_build(&dsp->pipeline,
						 len > 0 ? data : NULL);
			dsp_cmx_hardware(dsp->conf, dsp);
			dsp_rx_off(dsp);
		}
		break;
	case DSP_BF_ENABLE_KEY: /* turn blowfish on */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (len < 4 || len > 56) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: turn blowfish on (key "
			       "not shown)\n", __func__);
		ret = dsp_bf_init(dsp, (u8 *)data, len);
		/* set new cont */
		if (!ret)
			cont = DSP_BF_ACCEPT;
		else
			cont = DSP_BF_REJECT;
		/* send indication if it worked to set it */
		nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
					sizeof(int), &cont, GFP_ATOMIC);
		if (nskb) {
			if (dsp->up) {
				if (dsp->up->send(dsp->up, nskb))
					dev_kfree_skb(nskb);
			} else
				dev_kfree_skb(nskb);
		}
		if (!ret) {
			dsp_cmx_hardware(dsp->conf, dsp);
			dsp_dtmf_hardware(dsp);
			dsp_rx_off(dsp);
		}
		break;
	case DSP_BF_DISABLE: /* turn blowfish off */
		if (dsp->hdlc) {
			ret = -EINVAL;
			break;
		}
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
		dsp_bf_cleanup(dsp);
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_dtmf_hardware(dsp);
		dsp_rx_off(dsp);
		break;
	default:
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
			       __func__, cont);
		ret = -EINVAL;
	}
	return ret;
}

static void
get_features(struct mISDNchannel *ch)
{
	struct dsp		*dsp = container_of(ch, struct dsp, ch);
	struct mISDN_ctrl_req	cq;

	if (!ch->peer) {
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: no peer, no features\n",
			       __func__);
		return;
	}
	memset(&cq, 0, sizeof(cq));
	cq.op = MISDN_CTRL_GETOP;
	if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
		       __func__);
		return;
	}
	if (cq.op & MISDN_CTRL_RX_OFF)
		dsp->features_rx_off = 1;
	if (cq.op & MISDN_CTRL_FILL_EMPTY)
		dsp->features_fill_empty = 1;
	if (dsp_options & DSP_OPT_NOHARDWARE)
		return;
	if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
		cq.op = MISDN_CTRL_HW_FEATURES;
		*((u_long *)&cq.p1) = (u_long)&dsp->features;
		if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
			printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
			       __func__);
		}
	} else
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: features not supported for %s\n",
			       __func__, dsp->name);
}

static int
dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
{
	struct dsp		*dsp = container_of(ch, struct dsp, ch);
	struct mISDNhead	*hh;
	int			ret = 0;
	u8			*digits = NULL;
	u_long			flags;

	hh = mISDN_HEAD_P(skb);
	switch (hh->prim) {
		/* FROM DOWN */
	case (PH_DATA_CNF):
		dsp->data_pending = 0;
		/* trigger next hdlc frame, if any */
		if (dsp->hdlc) {
			spin_lock_irqsave(&dsp_lock, flags);
			if (dsp->b_active)
				schedule_work(&dsp->workq);
			spin_unlock_irqrestore(&dsp_lock, flags);
		}
		break;
	case (PH_DATA_IND):
	case (DL_DATA_IND):
		if (skb->len < 1) {
			ret = -EINVAL;
			break;
		}
		if (dsp->rx_is_off) {
			if (dsp_debug & DEBUG_DSP_CORE)
				printk(KERN_DEBUG "%s: rx-data during rx_off"
				       " for %s\n",
				       __func__, dsp->name);
		}
		if (dsp->hdlc) {
			/* hdlc */
			spin_lock_irqsave(&dsp_lock, flags);
			dsp_cmx_hdlc(dsp, skb);
			spin_unlock_irqrestore(&dsp_lock, flags);
			if (dsp->rx_disabled) {
				/* if receive is not allowed */
				break;
			}
			hh->prim = DL_DATA_IND;
			if (dsp->up)
				return dsp->up->send(dsp->up, skb);
			break;
		}

		spin_lock_irqsave(&dsp_lock, flags);

		/* decrypt if enabled */
		if (dsp->bf_enable)
			dsp_bf_decrypt(dsp, skb->data, skb->len);
		/* pipeline */
		if (dsp->pipeline.inuse)
			dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
						skb->len, hh->id);
		/* change volume if requested */
		if (dsp->rx_volume)
			dsp_change_volume(skb, dsp->rx_volume);
		/* check if dtmf soft decoding is turned on */
		if (dsp->dtmf.software) {
			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
							  skb->len, (dsp_options & DSP_OPT_ULAW) ? 1 : 0);
		}
		/* we need to process receive data if software */
		if (dsp->conf && dsp->conf->software) {
			/* process data from card at cmx */
			dsp_cmx_receive(dsp, skb);
		}

		spin_unlock_irqrestore(&dsp_lock, flags);

		/* send dtmf result, if any */
		if (digits) {
			while (*digits) {
				int k;
				struct sk_buff *nskb;
				if (dsp_debug & DEBUG_DSP_DTMF)
					printk(KERN_DEBUG "%s: digit"
					       "(%c) to layer %s\n",
					       __func__, *digits, dsp->name);
				k = *digits | DTMF_TONE_VAL;
				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
							MISDN_ID_ANY, sizeof(int), &k,
							GFP_ATOMIC);
				if (nskb) {
					if (dsp->up) {
						if (dsp->up->send(
							    dsp->up, nskb))
							dev_kfree_skb(nskb);
					} else
						dev_kfree_skb(nskb);
				}
				digits++;
			}
		}
		if (dsp->rx_disabled) {
			/* if receive is not allowed */
			break;
		}
		hh->prim = DL_DATA_IND;
		if (dsp->up)
			return dsp->up->send(dsp->up, skb);
		break;
	case (PH_CONTROL_IND):
		if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
			printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
			       "received: %x (len %d) %s\n", __func__,
			       hh->id, skb->len, dsp->name);
		switch (hh->id) {
		case (DTMF_HFC_COEF): /* getting coefficients */
			if (!dsp->dtmf.hardware) {
				if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
					printk(KERN_DEBUG "%s: ignoring DTMF "
					       "coefficients from HFC\n",
					       __func__);
				break;
			}
			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
							  skb->len, 2);
			while (*digits) {
				int k;
				struct sk_buff *nskb;
				if (dsp_debug & DEBUG_DSP_DTMF)
					printk(KERN_DEBUG "%s: digit"
					       "(%c) to layer %s\n",
					       __func__, *digits, dsp->name);
				k = *digits | DTMF_TONE_VAL;
				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
							MISDN_ID_ANY, sizeof(int), &k,
							GFP_ATOMIC);
				if (nskb) {
					if (dsp->up) {
						if (dsp->up->send(
							    dsp->up, nskb))
							dev_kfree_skb(nskb);
					} else
						dev_kfree_skb(nskb);
				}
				digits++;
			}
			break;
		case (HFC_VOL_CHANGE_TX): /* change volume */
			if (skb->len != sizeof(int)) {
				ret = -EINVAL;
				break;
			}
			spin_lock_irqsave(&dsp_lock, flags);
			dsp->tx_volume = *((int *)skb->data);
			if (dsp_debug & DEBUG_DSP_CORE)
				printk(KERN_DEBUG "%s: change tx volume to "
				       "%d\n", __func__, dsp->tx_volume);
			dsp_cmx_hardware(dsp->conf, dsp);
			dsp_dtmf_hardware(dsp);
			dsp_rx_off(dsp);
			spin_unlock_irqrestore(&dsp_lock, flags);
			break;
		default:
			if (dsp_debug & DEBUG_DSP_CORE)
				printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
				       "%s\n", __func__, hh->id, dsp->name);
			ret = -EINVAL;
		}
		break;
	case (PH_ACTIVATE_IND):
	case (PH_ACTIVATE_CNF):
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: b_channel is now active %s\n",
			       __func__, dsp->name);
		/* bchannel now active */
		spin_lock_irqsave(&dsp_lock, flags);
		dsp->b_active = 1;
		dsp->data_pending = 0;
		dsp->rx_init = 1;
		/* rx_W and rx_R will be adjusted on first frame */
		dsp->rx_W = 0;
		dsp->rx_R = 0;
		memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_dtmf_hardware(dsp);
		dsp_rx_off(dsp);
		spin_unlock_irqrestore(&dsp_lock, flags);
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: done with activation, sending "
			       "confirm to user space. %s\n", __func__,
			       dsp->name);
		/* send activation to upper layer */
		hh->prim = DL_ESTABLISH_CNF;
		if (dsp->up)
			return dsp->up->send(dsp->up, skb);
		break;
	case (PH_DEACTIVATE_IND):
	case (PH_DEACTIVATE_CNF):
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
			       __func__, dsp->name);
		/* bchannel now inactive */
		spin_lock_irqsave(&dsp_lock, flags);
		dsp->b_active = 0;
		dsp->data_pending = 0;
		dsp_cmx_hardware(dsp->conf, dsp);
		dsp_rx_off(dsp);
		spin_unlock_irqrestore(&dsp_lock, flags);
		hh->prim = DL_RELEASE_CNF;
		if (dsp->up)
			return dsp->up->send(dsp->up, skb);
		break;
		/* FROM UP */
	case (DL_DATA_REQ):
	case (PH_DATA_REQ):
		if (skb->len < 1) {
			ret = -EINVAL;
			break;
		}
		if (dsp->hdlc) {
			/* hdlc */
			if (!dsp->b_active) {
				ret = -EIO;
				break;
			}
			hh->prim = PH_DATA_REQ;
			spin_lock_irqsave(&dsp_lock, flags);
			skb_queue_tail(&dsp->sendq, skb);
			schedule_work(&dsp->workq);
			spin_unlock_irqrestore(&dsp_lock, flags);
			return 0;
		}
		/* send data to tx-buffer (if no tone is played) */
		if (!dsp->tone.tone) {
			spin_lock_irqsave(&dsp_lock, flags);
			dsp_cmx_transmit(dsp, skb);
			spin_unlock_irqrestore(&dsp_lock, flags);
		}
		break;
	case (PH_CONTROL_REQ):
		spin_lock_irqsave(&dsp_lock, flags);
		ret = dsp_control_req(dsp, hh, skb);
		spin_unlock_irqrestore(&dsp_lock, flags);
		break;
	case (DL_ESTABLISH_REQ):
	case (PH_ACTIVATE_REQ):
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: activating b_channel %s\n",
			       __func__, dsp->name);
		if (dsp->dtmf.hardware || dsp->dtmf.software)
			dsp_dtmf_goertzel_init(dsp);
		get_features(ch);
		/* enable fill_empty feature */
		if (dsp->features_fill_empty)
			dsp_fill_empty(dsp);
		/* send ph_activate */
		hh->prim = PH_ACTIVATE_REQ;
		if (ch->peer)
			return ch->recv(ch->peer, skb);
		break;
	case (DL_RELEASE_REQ):
	case (PH_DEACTIVATE_REQ):
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: releasing b_channel %s\n",
			       __func__, dsp->name);
		spin_lock_irqsave(&dsp_lock, flags);
		dsp->tone.tone = 0;
		dsp->tone.hardware = 0;
		dsp->tone.software = 0;
		if (timer_pending(&dsp->tone.tl))
			del_timer(&dsp->tone.tl);
		if (dsp->conf)
			dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
						 called here */
		skb_queue_purge(&dsp->sendq);
		spin_unlock_irqrestore(&dsp_lock, flags);
		hh->prim = PH_DEACTIVATE_REQ;
		if (ch->peer)
			return ch->recv(ch->peer, skb);
		break;
	default:
		if (dsp_debug & DEBUG_DSP_CORE)
			printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
			       __func__, hh->prim, dsp->name);
		ret = -EINVAL;
	}
	if (!ret)
		dev_kfree_skb(skb);
	return ret;
}

static int
dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
{
	struct dsp		*dsp = container_of(ch, struct dsp, ch);
	u_long		flags;
	int		err = 0;

	if (debug & DEBUG_DSP_CTRL)
		printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);

	switch (cmd) {
	case OPEN_CHANNEL:
		break;
	case CLOSE_CHANNEL:
		if (dsp->ch.peer)
			dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);

		/* wait until workqueue has finished,
		 * must lock here, or we may hit send-process currently
		 * queueing. */
		spin_lock_irqsave(&dsp_lock, flags);
		dsp->b_active = 0;
		spin_unlock_irqrestore(&dsp_lock, flags);
		/* MUST not be locked, because it waits until queue is done. */
		cancel_work_sync(&dsp->workq);
		spin_lock_irqsave(&dsp_lock, flags);
		if (timer_pending(&dsp->tone.tl))
			del_timer(&dsp->tone.tl);
		skb_queue_purge(&dsp->sendq);
		if (dsp_debug & DEBUG_DSP_CTRL)
			printk(KERN_DEBUG "%s: releasing member %s\n",
			       __func__, dsp->name);
		dsp->b_active = 0;
		dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
					 here */
		dsp_pipeline_destroy(&dsp->pipeline);

		if (dsp_debug & DEBUG_DSP_CTRL)
			printk(KERN_DEBUG "%s: remove & destroy object %s\n",
			       __func__, dsp->name);
		list_del(&dsp->list);
		spin_unlock_irqrestore(&dsp_lock, flags);

		if (dsp_debug & DEBUG_DSP_CTRL)
			printk(KERN_DEBUG "%s: dsp instance released\n",
			       __func__);
		vfree(dsp);
		module_put(THIS_MODULE);
		break;
	}
	return err;
}

static void
dsp_send_bh(struct work_struct *work)
{
	struct dsp *dsp = container_of(work, struct dsp, workq);
	struct sk_buff *skb;
	struct mISDNhead	*hh;

	if (dsp->hdlc && dsp->data_pending)
		return; /* wait until data has been acknowledged */

	/* send queued data */
	while ((skb = skb_dequeue(&dsp->sendq))) {
		/* in locked date, we must have still data in queue */
		if (dsp->data_pending) {
			if (dsp_debug & DEBUG_DSP_CORE)
				printk(KERN_DEBUG "%s: fifo full %s, this is "
				       "no bug!\n", __func__, dsp->name);
			/* flush transparent data, if not acked */
			dev_kfree_skb(skb);
			continue;
		}
		hh = mISDN_HEAD_P(skb);
		if (hh->prim == DL_DATA_REQ) {
			/* send packet up */
			if (dsp->up) {
				if (dsp->up->send(dsp->up, skb))
					dev_kfree_skb(skb);
			} else
				dev_kfree_skb(skb);
		} else {
			/* send packet down */
			if (dsp->ch.peer) {
				dsp->data_pending = 1;
				if (dsp->ch.recv(dsp->ch.peer, skb)) {
					dev_kfree_skb(skb);
					dsp->data_pending = 0;
				}
			} else
				dev_kfree_skb(skb);
		}
	}
}

static int
dspcreate(struct channel_req *crq)
{
	struct dsp		*ndsp;
	u_long		flags;

	if (crq->protocol != ISDN_P_B_L2DSP
	    && crq->protocol != ISDN_P_B_L2DSPHDLC)
		return -EPROTONOSUPPORT;
	ndsp = vzalloc(sizeof(struct dsp));
	if (!ndsp) {
		printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
		return -ENOMEM;
	}
	if (dsp_debug & DEBUG_DSP_CTRL)
		printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);

	/* default enabled */
	INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
	skb_queue_head_init(&ndsp->sendq);
	ndsp->ch.send = dsp_function;
	ndsp->ch.ctrl = dsp_ctrl;
	ndsp->up = crq->ch;
	crq->ch = &ndsp->ch;
	if (crq->protocol == ISDN_P_B_L2DSP) {
		crq->protocol = ISDN_P_B_RAW;
		ndsp->hdlc = 0;
	} else {
		crq->protocol = ISDN_P_B_HDLC;
		ndsp->hdlc = 1;
	}
	if (!try_module_get(THIS_MODULE))
		printk(KERN_WARNING "%s:cannot get module\n",
		       __func__);

	sprintf(ndsp->name, "DSP_C%x(0x%p)",
		ndsp->up->st->dev->id + 1, ndsp);
	/* set frame size to start */
	ndsp->features.hfc_id = -1; /* current PCM id */
	ndsp->features.pcm_id = -1; /* current PCM id */
	ndsp->pcm_slot_rx = -1; /* current CPM slot */
	ndsp->pcm_slot_tx = -1;
	ndsp->pcm_bank_rx = -1;
	ndsp->pcm_bank_tx = -1;
	ndsp->hfc_conf = -1; /* current conference number */
	/* set tone timer */
	ndsp->tone.tl.function = (void *)dsp_tone_timeout;
	ndsp->tone.tl.data = (long) ndsp;
	init_timer(&ndsp->tone.tl);

	if (dtmfthreshold < 20 || dtmfthreshold > 500)
		dtmfthreshold = 200;
	ndsp->dtmf.treshold = dtmfthreshold * 10000;

	/* init pipeline append to list */
	spin_lock_irqsave(&dsp_lock, flags);
	dsp_pipeline_init(&ndsp->pipeline);
	list_add_tail(&ndsp->list, &dsp_ilist);
	spin_unlock_irqrestore(&dsp_lock, flags);

	return 0;
}


static struct Bprotocol DSP = {
	.Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
	| (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
	.name = "dsp",
	.create = dspcreate
};

static int __init dsp_init(void)
{
	int err;
	int tics;

	printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);

	dsp_options = options;
	dsp_debug = debug;

	/* set packet size */
	dsp_poll = poll;
	if (dsp_poll) {
		if (dsp_poll > MAX_POLL) {
			printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
			       "maximum.\n", __func__, poll, MAX_POLL);
			err = -EINVAL;
			return err;
		}
		if (dsp_poll < 8) {
			printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
			       "minimum.\n", __func__, dsp_poll);
			err = -EINVAL;
			return err;
		}
		dsp_tics = poll * HZ / 8000;
		if (dsp_tics * 8000 != poll * HZ) {
			printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
			       "samples (0,125 ms). It is not a multiple of "
			       "%d HZ.\n", poll, HZ);
			err = -EINVAL;
			return err;
		}
	} else {
		poll = 8;
		while (poll <= MAX_POLL) {
			tics = (poll * HZ) / 8000;
			if (tics * 8000 == poll * HZ) {
				dsp_tics = tics;
				dsp_poll = poll;
				if (poll >= 64)
					break;
			}
			poll++;
		}
	}
	if (dsp_poll == 0) {
		printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
		       "clock that equals exactly the duration of 8-256 "
		       "samples. (Choose kernel clock speed like 100, 250, "
		       "300, 1000)\n");
		err = -EINVAL;
		return err;
	}
	printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
	       "%d jiffies.\n", dsp_poll, dsp_tics);

	spin_lock_init(&dsp_lock);
	INIT_LIST_HEAD(&dsp_ilist);
	INIT_LIST_HEAD(&conf_ilist);

	/* init conversion tables */
	dsp_audio_generate_law_tables();
	dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
	dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
		dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
	dsp_audio_generate_s2law_table();
	dsp_audio_generate_seven();
	dsp_audio_generate_mix_table();
	if (dsp_options & DSP_OPT_ULAW)
		dsp_audio_generate_ulaw_samples();
	dsp_audio_generate_volume_changes();

	err = dsp_pipeline_module_init();
	if (err) {
		printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
		       "error(%d)\n", err);
		return err;
	}

	err = mISDN_register_Bprotocol(&DSP);
	if (err) {
		printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
		return err;
	}

	/* set sample timer */
	dsp_spl_tl.function = (void *)dsp_cmx_send;
	dsp_spl_tl.data = 0;
	init_timer(&dsp_spl_tl);
	dsp_spl_tl.expires = jiffies + dsp_tics;
	dsp_spl_jiffies = dsp_spl_tl.expires;
	add_timer(&dsp_spl_tl);

	return 0;
}


static void __exit dsp_cleanup(void)
{
	mISDN_unregister_Bprotocol(&DSP);

	if (timer_pending(&dsp_spl_tl))
		del_timer(&dsp_spl_tl);

	if (!list_empty(&dsp_ilist)) {
		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
		       "empty.\n");
	}
	if (!list_empty(&conf_ilist)) {
		printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
		       "all memory freed.\n");
	}

	dsp_pipeline_module_exit();
}

module_init(dsp_init);
module_exit(dsp_cleanup);