summaryrefslogtreecommitdiff
path: root/sound/pci/trident/trident_synth.c
blob: 9b7dee84743bc16b367a71307677ead56d822ed8 (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
/*
 *  Routines for Trident 4DWave NX/DX soundcards - Synthesizer
 *  Copyright (c) by Scott McNab <jedi@tartarus.uwa.edu.au>
 *
 *
 *   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 <asm/io.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <sound/core.h>
#include <sound/trident.h>
#include <sound/seq_device.h>

MODULE_AUTHOR("Scott McNab <jedi@tartarus.uwa.edu.au>");
MODULE_DESCRIPTION("Routines for Trident 4DWave NX/DX soundcards - Synthesizer");
MODULE_LICENSE("GPL");

/* linear to log pan conversion table (4.2 channel attenuation format) */
static unsigned int pan_table[63] = {
	7959, 7733, 7514, 7301, 7093, 6892, 6697, 6507, 
	6322, 6143, 5968, 5799, 5634, 5475, 5319, 5168, 
	5022, 4879, 4741, 4606, 4475, 4349, 4225, 4105, 
	3989, 3876, 3766, 3659, 3555, 3454, 3356, 3261, 
	3168, 3078, 2991, 2906, 2824, 2744, 2666, 2590, 
	2517, 2445, 2376, 2308, 2243, 2179, 2117, 2057, 
	1999, 1942, 1887, 1833, 1781, 1731, 1682, 1634, 
	1588, 1543, 1499, 1456, 1415, 1375, 1336
};

#define LOG_TABLE_SIZE 386

/* Linear half-attenuation to log conversion table in the format:
 *   {linear volume, logarithmic attenuation equivalent}, ...
 *
 * Provides conversion from a linear half-volume value in the range
 * [0,8192] to a logarithmic attenuation value in the range 0 to 6.02dB.
 * Halving the linear volume is equivalent to an additional 6dB of 
 * logarithmic attenuation. The algorithm used in log_from_linear()
 * therefore uses this table as follows:
 * 
 * - loop and for every time the volume is less than half the maximum 
 *   volume (16384), add another 6dB and halve the maximum value used
 *   for this comparison.
 * - when the volume is greater than half the maximum volume, take
 *   the difference of the volume to half volume (in the range [0,8192])
 *   and look up the log_table[] to find the nearest entry.
 * - take the logarithic component of this entry and add it to the 
 *   resulting attenuation.
 *
 * Thus this routine provides a linear->log conversion for a range of
 * [0,16384] using only 386 table entries
 *
 * Note: although this table stores log attenuation in 8.8 format, values
 * were only calculated for 6 bits fractional precision, since that is
 * the most precision offered by the trident hardware.
 */

static unsigned short log_table[LOG_TABLE_SIZE*2] =
{
	4, 0x0604, 19, 0x0600, 34, 0x05fc, 
	49, 0x05f8, 63, 0x05f4, 78, 0x05f0, 93, 0x05ec, 108, 0x05e8, 
	123, 0x05e4, 138, 0x05e0, 153, 0x05dc, 168, 0x05d8, 183, 0x05d4, 
	198, 0x05d0, 213, 0x05cc, 228, 0x05c8, 244, 0x05c4, 259, 0x05c0, 
	274, 0x05bc, 289, 0x05b8, 304, 0x05b4, 320, 0x05b0, 335, 0x05ac, 
	350, 0x05a8, 366, 0x05a4, 381, 0x05a0, 397, 0x059c, 412, 0x0598, 
	428, 0x0594, 443, 0x0590, 459, 0x058c, 474, 0x0588, 490, 0x0584, 
	506, 0x0580, 521, 0x057c, 537, 0x0578, 553, 0x0574, 568, 0x0570, 
	584, 0x056c, 600, 0x0568, 616, 0x0564, 632, 0x0560, 647, 0x055c, 
	663, 0x0558, 679, 0x0554, 695, 0x0550, 711, 0x054c, 727, 0x0548, 
	743, 0x0544, 759, 0x0540, 776, 0x053c, 792, 0x0538, 808, 0x0534, 
	824, 0x0530, 840, 0x052c, 857, 0x0528, 873, 0x0524, 889, 0x0520, 
	906, 0x051c, 922, 0x0518, 938, 0x0514, 955, 0x0510, 971, 0x050c, 
	988, 0x0508, 1004, 0x0504, 1021, 0x0500, 1037, 0x04fc, 1054, 0x04f8, 
	1071, 0x04f4, 1087, 0x04f0, 1104, 0x04ec, 1121, 0x04e8, 1138, 0x04e4, 
	1154, 0x04e0, 1171, 0x04dc, 1188, 0x04d8, 1205, 0x04d4, 1222, 0x04d0, 
	1239, 0x04cc, 1256, 0x04c8, 1273, 0x04c4, 1290, 0x04c0, 1307, 0x04bc, 
	1324, 0x04b8, 1341, 0x04b4, 1358, 0x04b0, 1376, 0x04ac, 1393, 0x04a8, 
	1410, 0x04a4, 1427, 0x04a0, 1445, 0x049c, 1462, 0x0498, 1479, 0x0494, 
	1497, 0x0490, 1514, 0x048c, 1532, 0x0488, 1549, 0x0484, 1567, 0x0480, 
	1584, 0x047c, 1602, 0x0478, 1620, 0x0474, 1637, 0x0470, 1655, 0x046c, 
	1673, 0x0468, 1690, 0x0464, 1708, 0x0460, 1726, 0x045c, 1744, 0x0458, 
	1762, 0x0454, 1780, 0x0450, 1798, 0x044c, 1816, 0x0448, 1834, 0x0444, 
	1852, 0x0440, 1870, 0x043c, 1888, 0x0438, 1906, 0x0434, 1924, 0x0430, 
	1943, 0x042c, 1961, 0x0428, 1979, 0x0424, 1997, 0x0420, 2016, 0x041c, 
	2034, 0x0418, 2053, 0x0414, 2071, 0x0410, 2089, 0x040c, 2108, 0x0408, 
	2127, 0x0404, 2145, 0x0400, 2164, 0x03fc, 2182, 0x03f8, 2201, 0x03f4, 
	2220, 0x03f0, 2239, 0x03ec, 2257, 0x03e8, 2276, 0x03e4, 2295, 0x03e0, 
	2314, 0x03dc, 2333, 0x03d8, 2352, 0x03d4, 2371, 0x03d0, 2390, 0x03cc, 
	2409, 0x03c8, 2428, 0x03c4, 2447, 0x03c0, 2466, 0x03bc, 2485, 0x03b8, 
	2505, 0x03b4, 2524, 0x03b0, 2543, 0x03ac, 2562, 0x03a8, 2582, 0x03a4, 
	2601, 0x03a0, 2621, 0x039c, 2640, 0x0398, 2660, 0x0394, 2679, 0x0390, 
	2699, 0x038c, 2718, 0x0388, 2738, 0x0384, 2758, 0x0380, 2777, 0x037c, 
	2797, 0x0378, 2817, 0x0374, 2837, 0x0370, 2857, 0x036c, 2876, 0x0368, 
	2896, 0x0364, 2916, 0x0360, 2936, 0x035c, 2956, 0x0358, 2976, 0x0354, 
	2997, 0x0350, 3017, 0x034c, 3037, 0x0348, 3057, 0x0344, 3077, 0x0340, 
	3098, 0x033c, 3118, 0x0338, 3138, 0x0334, 3159, 0x0330, 3179, 0x032c, 
	3200, 0x0328, 3220, 0x0324, 3241, 0x0320, 3261, 0x031c, 3282, 0x0318, 
	3303, 0x0314, 3323, 0x0310, 3344, 0x030c, 3365, 0x0308, 3386, 0x0304, 
	3406, 0x0300, 3427, 0x02fc, 3448, 0x02f8, 3469, 0x02f4, 3490, 0x02f0, 
	3511, 0x02ec, 3532, 0x02e8, 3553, 0x02e4, 3575, 0x02e0, 3596, 0x02dc, 
	3617, 0x02d8, 3638, 0x02d4, 3660, 0x02d0, 3681, 0x02cc, 3702, 0x02c8, 
	3724, 0x02c4, 3745, 0x02c0, 3767, 0x02bc, 3788, 0x02b8, 3810, 0x02b4, 
	3831, 0x02b0, 3853, 0x02ac, 3875, 0x02a8, 3896, 0x02a4, 3918, 0x02a0, 
	3940, 0x029c, 3962, 0x0298, 3984, 0x0294, 4006, 0x0290, 4028, 0x028c, 
	4050, 0x0288, 4072, 0x0284, 4094, 0x0280, 4116, 0x027c, 4138, 0x0278, 
	4160, 0x0274, 4182, 0x0270, 4205, 0x026c, 4227, 0x0268, 4249, 0x0264, 
	4272, 0x0260, 4294, 0x025c, 4317, 0x0258, 4339, 0x0254, 4362, 0x0250, 
	4384, 0x024c, 4407, 0x0248, 4430, 0x0244, 4453, 0x0240, 4475, 0x023c, 
	4498, 0x0238, 4521, 0x0234, 4544, 0x0230, 4567, 0x022c, 4590, 0x0228, 
	4613, 0x0224, 4636, 0x0220, 4659, 0x021c, 4682, 0x0218, 4705, 0x0214, 
	4728, 0x0210, 4752, 0x020c, 4775, 0x0208, 4798, 0x0204, 4822, 0x0200, 
	4845, 0x01fc, 4869, 0x01f8, 4892, 0x01f4, 4916, 0x01f0, 4939, 0x01ec, 
	4963, 0x01e8, 4987, 0x01e4, 5010, 0x01e0, 5034, 0x01dc, 5058, 0x01d8, 
	5082, 0x01d4, 5106, 0x01d0, 5130, 0x01cc, 5154, 0x01c8, 5178, 0x01c4, 
	5202, 0x01c0, 5226, 0x01bc, 5250, 0x01b8, 5274, 0x01b4, 5299, 0x01b0, 
	5323, 0x01ac, 5347, 0x01a8, 5372, 0x01a4, 5396, 0x01a0, 5420, 0x019c, 
	5445, 0x0198, 5469, 0x0194, 5494, 0x0190, 5519, 0x018c, 5543, 0x0188, 
	5568, 0x0184, 5593, 0x0180, 5618, 0x017c, 5643, 0x0178, 5668, 0x0174, 
	5692, 0x0170, 5717, 0x016c, 5743, 0x0168, 5768, 0x0164, 5793, 0x0160, 
	5818, 0x015c, 5843, 0x0158, 5868, 0x0154, 5894, 0x0150, 5919, 0x014c, 
	5945, 0x0148, 5970, 0x0144, 5995, 0x0140, 6021, 0x013c, 6047, 0x0138, 
	6072, 0x0134, 6098, 0x0130, 6124, 0x012c, 6149, 0x0128, 6175, 0x0124, 
	6201, 0x0120, 6227, 0x011c, 6253, 0x0118, 6279, 0x0114, 6305, 0x0110, 
	6331, 0x010c, 6357, 0x0108, 6384, 0x0104, 6410, 0x0100, 6436, 0x00fc, 
	6462, 0x00f8, 6489, 0x00f4, 6515, 0x00f0, 6542, 0x00ec, 6568, 0x00e8, 
	6595, 0x00e4, 6621, 0x00e0, 6648, 0x00dc, 6675, 0x00d8, 6702, 0x00d4, 
	6728, 0x00d0, 6755, 0x00cc, 6782, 0x00c8, 6809, 0x00c4, 6836, 0x00c0, 
	6863, 0x00bc, 6890, 0x00b8, 6917, 0x00b4, 6945, 0x00b0, 6972, 0x00ac, 
	6999, 0x00a8, 7027, 0x00a4, 7054, 0x00a0, 7081, 0x009c, 7109, 0x0098, 
	7136, 0x0094, 7164, 0x0090, 7192, 0x008c, 7219, 0x0088, 7247, 0x0084, 
	7275, 0x0080, 7303, 0x007c, 7331, 0x0078, 7359, 0x0074, 7387, 0x0070, 
	7415, 0x006c, 7443, 0x0068, 7471, 0x0064, 7499, 0x0060, 7527, 0x005c, 
	7556, 0x0058, 7584, 0x0054, 7613, 0x0050, 7641, 0x004c, 7669, 0x0048, 
	7698, 0x0044, 7727, 0x0040, 7755, 0x003c, 7784, 0x0038, 7813, 0x0034, 
	7842, 0x0030, 7870, 0x002c, 7899, 0x0028, 7928, 0x0024, 7957, 0x0020, 
	7986, 0x001c, 8016, 0x0018, 8045, 0x0014, 8074, 0x0010, 8103, 0x000c, 
	8133, 0x0008, 8162, 0x0004, 8192, 0x0000
};

static unsigned short lookup_volume_table( unsigned short value )
{
	/* This code is an optimised version of:
	 *   int i = 0;
	 *   while( volume_table[i*2] < value )
	 *       i++;
	 *   return volume_table[i*2+1];
	 */
	unsigned short *ptr = log_table;
	while( *ptr < value )
		ptr += 2;
	return *(ptr+1);
}

/* this function calculates a 8.8 fixed point logarithmic attenuation
 * value from a linear volume value in the range 0 to 16384 */
static unsigned short log_from_linear( unsigned short value )
{
	if (value >= 16384)
		return 0x0000;
	if (value) {
		unsigned short result = 0;
		int v, c;
		for( c = 0, v = 8192; c < 14; c++, v >>= 1 ) {
			if( value >= v ) {
				result += lookup_volume_table( (value - v) << c );
				return result;
			}
			result += 0x0605;	/* 6.0205 (result of -20*log10(0.5)) */
		}
	}
	return 0xffff;
}

/*
 * Sample handling operations
 */

static void sample_start(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_position_t position);
static void sample_stop(struct snd_trident * trident, struct snd_trident_voice * voice, int mode);
static void sample_freq(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_frequency_t freq);
static void sample_volume(struct snd_trident * trident, struct snd_trident_voice * voice, struct snd_seq_ev_volume * volume);
static void sample_loop(struct snd_trident * trident, struct snd_trident_voice * voice, struct snd_seq_ev_loop * loop);
static void sample_pos(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_position_t position);
static void sample_private1(struct snd_trident * trident, struct snd_trident_voice * voice, unsigned char *data);

static struct snd_trident_sample_ops sample_ops =
{
	sample_start,
	sample_stop,
	sample_freq,
	sample_volume,
	sample_loop,
	sample_pos,
	sample_private1
};

static void snd_trident_simple_init(struct snd_trident_voice * voice)
{
	//voice->handler_wave = interrupt_wave;
	//voice->handler_volume = interrupt_volume;
	//voice->handler_effect = interrupt_effect;
	//voice->volume_change = NULL;
	voice->sample_ops = &sample_ops;
}

static void sample_start(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_position_t position)
{
	struct simple_instrument *simple;
	struct snd_seq_kinstr *instr;
	unsigned long flags;
	unsigned int loop_start, loop_end, sample_start, sample_end, start_offset;
	unsigned int value;
	unsigned int shift = 0;

	instr = snd_seq_instr_find(trident->synth.ilist, &voice->instr, 0, 1);
	if (instr == NULL)
		return;
	voice->instr = instr->instr;	/* copy ID to speedup aliases */
	simple = KINSTR_DATA(instr);

	spin_lock_irqsave(&trident->reg_lock, flags);

	if (trident->device == TRIDENT_DEVICE_ID_SI7018)
		voice->GVSel = 1;	/* route to Wave volume */

	voice->CTRL = 0;
	voice->Alpha = 0;
	voice->FMS = 0;

	loop_start = simple->loop_start >> 4;
	loop_end = simple->loop_end >> 4;
	sample_start = (simple->start + position) >> 4;
	if( sample_start >= simple->size )
		sample_start = simple->start >> 4;
	sample_end = simple->size;
	start_offset = position >> 4;

	if (simple->format & SIMPLE_WAVE_16BIT) {
		voice->CTRL |= 8;
		shift++;
	}
	if (simple->format & SIMPLE_WAVE_STEREO) {
		voice->CTRL |= 4;
		shift++;
	}
	if (!(simple->format & SIMPLE_WAVE_UNSIGNED))
		voice->CTRL |= 2;

	voice->LBA = simple->address.memory;

	if (simple->format & SIMPLE_WAVE_LOOP) {
		voice->CTRL |= 1;
		voice->LBA += loop_start << shift;
		if( start_offset >= loop_start ) {
			voice->CSO = start_offset - loop_start;
			voice->negCSO = 0;
		} else {
			voice->CSO = loop_start - start_offset;
			voice->negCSO = 1;
		}
		voice->ESO = loop_end - loop_start - 1;
	} else {
		voice->LBA += start_offset << shift;
		voice->CSO = sample_start;
		voice->ESO = sample_end - 1;
		voice->negCSO = 0;
	}

	if (voice->flags & SNDRV_TRIDENT_VFLG_RUNNING) {
		snd_trident_stop_voice(trident, voice->number);
		voice->flags &= ~SNDRV_TRIDENT_VFLG_RUNNING;
	}

	/* set CSO sign */
	value = inl(TRID_REG(trident, T4D_SIGN_CSO_A));
	if( voice->negCSO ) {
		value |= 1 << (voice->number&31);
	} else {
		value &= ~(1 << (voice->number&31));
	}
	outl(value,TRID_REG(trident, T4D_SIGN_CSO_A));

	voice->Attribute = 0;	
	snd_trident_write_voice_regs(trident, voice);
	snd_trident_start_voice(trident, voice->number);
	voice->flags |= SNDRV_TRIDENT_VFLG_RUNNING;
	spin_unlock_irqrestore(&trident->reg_lock, flags);
	snd_seq_instr_free_use(trident->synth.ilist, instr);
}

static void sample_stop(struct snd_trident * trident, struct snd_trident_voice * voice, int mode)
{
	unsigned long flags;

	if (!(voice->flags & SNDRV_TRIDENT_VFLG_RUNNING))
		return;

	switch (mode) {
	default:
		spin_lock_irqsave(&trident->reg_lock, flags);
		snd_trident_stop_voice(trident, voice->number);
		voice->flags &= ~SNDRV_TRIDENT_VFLG_RUNNING;
		spin_unlock_irqrestore(&trident->reg_lock, flags);
		break;
	case SAMPLE_STOP_LOOP:	/* disable loop only */
		voice->CTRL &= ~1;
		spin_lock_irqsave(&trident->reg_lock, flags);
		outb((unsigned char) voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
		outw((((voice->CTRL << 12) | (voice->EC & 0x0fff)) & 0xffff), CH_GVSEL_PAN_VOL_CTRL_EC);
		spin_unlock_irqrestore(&trident->reg_lock, flags);
		break;
	}
}

static void sample_freq(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_frequency_t freq)
{
	unsigned long flags;
	freq >>= 4;

	spin_lock_irqsave(&trident->reg_lock, flags);
	if (freq == 44100)
		voice->Delta = 0xeb3;
	else if (freq == 8000)
		voice->Delta = 0x2ab;
	else if (freq == 48000)
		voice->Delta = 0x1000;
	else
		voice->Delta = (((freq << 12) + freq) / 48000) & 0x0000ffff;

	outb((unsigned char) voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
	if (trident->device == TRIDENT_DEVICE_ID_NX) {
		outb((unsigned char) voice->Delta, TRID_REG(trident, CH_NX_DELTA_CSO + 3));
		outb((unsigned char) (voice->Delta >> 8), TRID_REG(trident, CH_NX_DELTA_ESO + 3));
	} else {
		outw((unsigned short) voice->Delta, TRID_REG(trident, CH_DX_ESO_DELTA));
	}

	spin_unlock_irqrestore(&trident->reg_lock, flags);
}

static void sample_volume(struct snd_trident * trident, struct snd_trident_voice * voice, struct snd_seq_ev_volume * volume)
{
	unsigned long flags;
	unsigned short value;

	spin_lock_irqsave(&trident->reg_lock, flags);
	voice->GVSel = 0;	/* use global music volume */
	voice->FMC = 0x03;	/* fixme: can we do something useful with FMC? */
	if (volume->volume >= 0) {
		volume->volume &= 0x3fff;
		/* linear volume -> logarithmic attenuation conversion
		 * uses EC register for greater resolution (6.6 bits) than Vol register (5.3 bits)
		 * Vol register used when additional attenuation is required */
		voice->RVol = 0;
		voice->CVol = 0;
		value = log_from_linear( volume->volume );
		voice->Vol = 0;
		voice->EC = (value & 0x3fff) >> 2;
		if (value > 0x3fff) {
			voice->EC |= 0xfc0;
			if (value < 0x5f00 )
				voice->Vol = ((value >> 8) - 0x3f) << 5;
			else {
				voice->Vol = 0x3ff;
				voice->EC = 0xfff;
			}
		}
	}
	if (volume->lr >= 0) {
		volume->lr &= 0x3fff;
		/* approximate linear pan by attenuating channels */
		if (volume->lr >= 0x2000) {	/* attenuate left (pan right) */
			value = 0x3fff - volume->lr;
			for (voice->Pan = 0; voice->Pan < 63; voice->Pan++ ) 
				if (value >= pan_table[voice->Pan] )
					break;
		} else {			/* attenuate right (pan left) */
			for (voice->Pan = 0; voice->Pan < 63; voice->Pan++ ) 
				if ((unsigned int)volume->lr >= pan_table[voice->Pan] )
					break;
			voice->Pan |= 0x40;
		}
	}
	outb((unsigned char) voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
	outl((voice->GVSel << 31) | ((voice->Pan & 0x0000007f) << 24) |
		 ((voice->Vol & 0x000000ff) << 16) | ((voice->CTRL & 0x0000000f) << 12) |
		 (voice->EC & 0x00000fff), TRID_REG(trident, CH_GVSEL_PAN_VOL_CTRL_EC));
	value = ((voice->FMC & 0x03) << 14) | ((voice->RVol & 0x7f) << 7) | (voice->CVol & 0x7f);
	outw(value, TRID_REG(trident, CH_DX_FMC_RVOL_CVOL));
	spin_unlock_irqrestore(&trident->reg_lock, flags);
}

static void sample_loop(struct snd_trident * trident, struct snd_trident_voice * voice, struct snd_seq_ev_loop * loop)
{
	unsigned long flags;
	struct simple_instrument *simple;
	struct snd_seq_kinstr *instr;
	unsigned int loop_start, loop_end;

	instr = snd_seq_instr_find(trident->synth.ilist, &voice->instr, 0, 1);
	if (instr == NULL)
		return;
	voice->instr = instr->instr;	/* copy ID to speedup aliases */
	simple = KINSTR_DATA(instr);

	loop_start = loop->start >> 4;
	loop_end = loop->end >> 4;

	spin_lock_irqsave(&trident->reg_lock, flags);

	voice->LBA = simple->address.memory + loop_start;
	voice->CSO = 0;
	voice->ESO = loop_end - loop_start - 1;

	outb((unsigned char) voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
	outb((voice->LBA >> 16), TRID_REG(trident, CH_LBA + 2));
	outw((voice->LBA & 0xffff), TRID_REG(trident, CH_LBA));
	if (trident->device == TRIDENT_DEVICE_ID_NX) {
		outb((voice->ESO >> 16), TRID_REG(trident, CH_NX_DELTA_ESO + 2));
		outw((voice->ESO & 0xffff), TRID_REG(trident, CH_NX_DELTA_ESO));
		outb((voice->CSO >> 16), TRID_REG(trident, CH_NX_DELTA_CSO + 2));
		outw((voice->CSO & 0xffff), TRID_REG(trident, CH_NX_DELTA_CSO));
	} else {
		outw((voice->ESO & 0xffff), TRID_REG(trident, CH_DX_ESO_DELTA + 2));
		outw((voice->CSO & 0xffff), TRID_REG(trident, CH_DX_CSO_ALPHA_FMS + 2));
	}

	spin_unlock_irqrestore(&trident->reg_lock, flags);
	snd_seq_instr_free_use(trident->synth.ilist, instr);
}

static void sample_pos(struct snd_trident * trident, struct snd_trident_voice * voice, snd_seq_position_t position)
{
	unsigned long flags;
	struct simple_instrument *simple;
	struct snd_seq_kinstr *instr;
	unsigned int value;

	instr = snd_seq_instr_find(trident->synth.ilist, &voice->instr, 0, 1);
	if (instr == NULL)
		return;
	voice->instr = instr->instr;	/* copy ID to speedup aliases */
	simple = KINSTR_DATA(instr);

	spin_lock_irqsave(&trident->reg_lock, flags);

	if (simple->format & SIMPLE_WAVE_LOOP) {
		if( position >= simple->loop_start ) {
			voice->CSO = (position - simple->loop_start) >> 4;
			voice->negCSO = 0;
		} else {
			voice->CSO = (simple->loop_start - position) >> 4;
			voice->negCSO = 1;
		}
	} else {
		voice->CSO = position >> 4;
		voice->negCSO = 0;
	}

	/* set CSO sign */
	value = inl(TRID_REG(trident, T4D_SIGN_CSO_A));
	if( voice->negCSO ) {
		value |= 1 << (voice->number&31);
	} else {
		value &= ~(1 << (voice->number&31));
	}
	outl(value,TRID_REG(trident, T4D_SIGN_CSO_A));
	

	outb((unsigned char) voice->number, TRID_REG(trident, T4D_LFO_GC_CIR));
	if (trident->device == TRIDENT_DEVICE_ID_NX) {
		outw((voice->CSO & 0xffff), TRID_REG(trident, CH_NX_DELTA_CSO));
		outb((voice->CSO >> 16), TRID_REG(trident, CH_NX_DELTA_CSO + 2));
	} else {
		outw((voice->CSO & 0xffff), TRID_REG(trident, CH_DX_CSO_ALPHA_FMS) + 2);
	}

	spin_unlock_irqrestore(&trident->reg_lock, flags);
	snd_seq_instr_free_use(trident->synth.ilist, instr);
}

static void sample_private1(struct snd_trident * trident, struct snd_trident_voice * voice, unsigned char *data)
{
}

/*
 * Memory management / sample loading
 */

static int snd_trident_simple_put_sample(void *private_data,
					 struct simple_instrument * instr,
					 char __user *data, long len, int atomic)
{
	struct snd_trident *trident = private_data;
	int size = instr->size;
	int shift = 0;

	if (instr->format & SIMPLE_WAVE_BACKWARD ||
	    instr->format & SIMPLE_WAVE_BIDIR ||
	    instr->format & SIMPLE_WAVE_ULAW) 
		return -EINVAL;	/* not supported */

	if (instr->format & SIMPLE_WAVE_16BIT)
		shift++;
	if (instr->format & SIMPLE_WAVE_STEREO)
		shift++;
	size <<= shift;

	if (trident->synth.current_size + size > trident->synth.max_size)
		return -ENOMEM;

	if (!access_ok(VERIFY_READ, data, size))
		return -EFAULT;

	if (trident->tlb.entries) {
		struct snd_util_memblk *memblk;
		memblk = snd_trident_synth_alloc(trident, size); 
		if (memblk == NULL)
			return -ENOMEM;
		if (snd_trident_synth_copy_from_user(trident, memblk, 0, data, size) ) {
			snd_trident_synth_free(trident, memblk);
			return -EFAULT;
		}
		instr->address.ptr = (unsigned char*)memblk;
		instr->address.memory = memblk->offset;
	} else {
		struct snd_dma_buffer dmab;
		if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(trident->pci),
					size, &dmab) < 0)
			return -ENOMEM;

		if (copy_from_user(dmab.area, data, size)) {
			snd_dma_free_pages(&dmab);
			return -EFAULT;
		}
		instr->address.ptr = dmab.area;
		instr->address.memory = dmab.addr;
	}

	trident->synth.current_size += size;
	return 0;
}

static int snd_trident_simple_get_sample(void *private_data,
					 struct simple_instrument * instr,
					 char __user *data, long len, int atomic)
{
	//struct snd_trident *trident = private_data;
	int size = instr->size;
	int shift = 0;

	if (instr->format & SIMPLE_WAVE_16BIT)
		shift++;
	if (instr->format & SIMPLE_WAVE_STEREO)
		shift++;
	size <<= shift;

	if (!access_ok(VERIFY_WRITE, data, size))
		return -EFAULT;

	/* FIXME: not implemented yet */

	return -EBUSY;
}

static int snd_trident_simple_remove_sample(void *private_data,
					    struct simple_instrument * instr,
					    int atomic)
{
	struct snd_trident *trident = private_data;
	int size = instr->size;

	if (instr->format & SIMPLE_WAVE_16BIT)
		size <<= 1;
	if (instr->format & SIMPLE_WAVE_STEREO)
		size <<= 1;

	if (trident->tlb.entries) {
		struct snd_util_memblk *memblk = (struct snd_util_memblk *)instr->address.ptr;
		if (memblk)
			snd_trident_synth_free(trident, memblk);
		else
			return -EFAULT;
	} else {
		struct snd_dma_buffer dmab;
		dmab.dev.type = SNDRV_DMA_TYPE_DEV;
		dmab.dev.dev = snd_dma_pci_data(trident->pci);
		dmab.area = instr->address.ptr;
		dmab.addr = instr->address.memory;
		dmab.bytes = size;
		snd_dma_free_pages(&dmab);
	}

	trident->synth.current_size -= size;
	if (trident->synth.current_size < 0)	/* shouldn't need this check... */
		trident->synth.current_size = 0;

	return 0;
}

static void select_instrument(struct snd_trident * trident, struct snd_trident_voice * v)
{
	struct snd_seq_kinstr *instr;
	instr = snd_seq_instr_find(trident->synth.ilist, &v->instr, 0, 1);
	if (instr != NULL) {
		if (instr->ops) {
			if (!strcmp(instr->ops->instr_type, SNDRV_SEQ_INSTR_ID_SIMPLE))
				snd_trident_simple_init(v);
		}
		snd_seq_instr_free_use(trident->synth.ilist, instr);
	}
}

/*

 */

static void event_sample(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_stop)
		v->sample_ops->sample_stop(p->trident, v, SAMPLE_STOP_IMMEDIATELY);
	v->instr.std = ev->data.sample.param.sample.std;
	if (v->instr.std & 0xff000000) {	/* private instrument */
		v->instr.std &= 0x00ffffff;
		v->instr.std |= (unsigned int)ev->source.client << 24;
	}
	v->instr.bank = ev->data.sample.param.sample.bank;
	v->instr.prg = ev->data.sample.param.sample.prg;
	select_instrument(p->trident, v);
}

static void event_cluster(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_stop)
		v->sample_ops->sample_stop(p->trident, v, SAMPLE_STOP_IMMEDIATELY);
	v->instr.cluster = ev->data.sample.param.cluster.cluster;
	select_instrument(p->trident, v);
}

static void event_start(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_start)
		v->sample_ops->sample_start(p->trident, v, ev->data.sample.param.position);
}

static void event_stop(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_stop)
		v->sample_ops->sample_stop(p->trident, v, ev->data.sample.param.stop_mode);
}

static void event_freq(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_freq)
		v->sample_ops->sample_freq(p->trident, v, ev->data.sample.param.frequency);
}

static void event_volume(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_volume)
		v->sample_ops->sample_volume(p->trident, v, &ev->data.sample.param.volume);
}

static void event_loop(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_loop)
		v->sample_ops->sample_loop(p->trident, v, &ev->data.sample.param.loop);
}

static void event_position(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_pos)
		v->sample_ops->sample_pos(p->trident, v, ev->data.sample.param.position);
}

static void event_private1(struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v)
{
	if (v->sample_ops && v->sample_ops->sample_private1)
		v->sample_ops->sample_private1(p->trident, v, (unsigned char *) &ev->data.sample.param.raw8);
}

typedef void (trident_sample_event_handler_t) (struct snd_seq_event * ev, struct snd_trident_port * p, struct snd_trident_voice * v);

static trident_sample_event_handler_t *trident_sample_event_handlers[9] =
{
	event_sample,
	event_cluster,
	event_start,
	event_stop,
	event_freq,
	event_volume,
	event_loop,
	event_position,
	event_private1
};

static void snd_trident_sample_event(struct snd_seq_event * ev, struct snd_trident_port * p)
{
	int idx, voice;
	struct snd_trident *trident = p->trident;
	struct snd_trident_voice *v;
	unsigned long flags;

	idx = ev->type - SNDRV_SEQ_EVENT_SAMPLE;
	if (idx < 0 || idx > 8)
		return;
	for (voice = 0; voice < 64; voice++) {
		v = &trident->synth.voices[voice];
		if (v->use && v->client == ev->source.client &&
		    v->port == ev->source.port &&
		    v->index == ev->data.sample.channel) {
			spin_lock_irqsave(&trident->event_lock, flags);
			trident_sample_event_handlers[idx] (ev, p, v);
			spin_unlock_irqrestore(&trident->event_lock, flags);
			return;
		}
	}
}

/*

 */

static void snd_trident_synth_free_voices(struct snd_trident * trident, int client, int port)
{
	int idx;
	struct snd_trident_voice *voice;

	for (idx = 0; idx < 32; idx++) {
		voice = &trident->synth.voices[idx];
		if (voice->use && voice->client == client && voice->port == port)
			snd_trident_free_voice(trident, voice);
	}
}

static int snd_trident_synth_use(void *private_data, struct snd_seq_port_subscribe * info)
{
	struct snd_trident_port *port = private_data;
	struct snd_trident *trident = port->trident;
	struct snd_trident_voice *voice;
	unsigned int idx;
	unsigned long flags;

	if (info->voices > 32)
		return -EINVAL;
	spin_lock_irqsave(&trident->reg_lock, flags);
	for (idx = 0; idx < info->voices; idx++) {
		voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_SYNTH, info->sender.client, info->sender.port);
		if (voice == NULL) {
			snd_trident_synth_free_voices(trident, info->sender.client, info->sender.port);
			spin_unlock_irqrestore(&trident->reg_lock, flags);
			return -EBUSY;
		}
		voice->index = idx;
		voice->Vol = 0x3ff;
		voice->EC = 0x0fff;
	}
#if 0
	for (idx = 0; idx < info->midi_voices; idx++) {
		port->midi_has_voices = 1;
		voice = snd_trident_alloc_voice(trident, SNDRV_TRIDENT_VOICE_TYPE_MIDI, info->sender.client, info->sender.port);
		if (voice == NULL) {
			snd_trident_synth_free_voices(trident, info->sender.client, info->sender.port);
			spin_unlock_irqrestore(&trident->reg_lock, flags);
			return -EBUSY;
		}
		voice->Vol = 0x3ff;
		voice->EC = 0x0fff;
	}
#endif
	spin_unlock_irqrestore(&trident->reg_lock, flags);
	return 0;
}

static int snd_trident_synth_unuse(void *private_data, struct snd_seq_port_subscribe * info)
{
	struct snd_trident_port *port = private_data;
	struct snd_trident *trident = port->trident;
	unsigned long flags;

	spin_lock_irqsave(&trident->reg_lock, flags);
	snd_trident_synth_free_voices(trident, info->sender.client, info->sender.port);
	spin_unlock_irqrestore(&trident->reg_lock, flags);
	return 0;
}

/*

 */

static void snd_trident_synth_free_private_instruments(struct snd_trident_port * p, int client)
{
	struct snd_seq_instr_header ifree;

	memset(&ifree, 0, sizeof(ifree));
	ifree.cmd = SNDRV_SEQ_INSTR_FREE_CMD_PRIVATE;
	snd_seq_instr_list_free_cond(p->trident->synth.ilist, &ifree, client, 0);
}

static int snd_trident_synth_event_input(struct snd_seq_event * ev, int direct, void *private_data, int atomic, int hop)
{
	struct snd_trident_port *p = (struct snd_trident_port *) private_data;

	if (p == NULL)
		return -EINVAL;
	if (ev->type >= SNDRV_SEQ_EVENT_SAMPLE &&
	    ev->type <= SNDRV_SEQ_EVENT_SAMPLE_PRIVATE1) {
		snd_trident_sample_event(ev, p);
		return 0;
	}
	if (ev->source.client == SNDRV_SEQ_CLIENT_SYSTEM &&
	    ev->source.port == SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE) {
		if (ev->type == SNDRV_SEQ_EVENT_CLIENT_EXIT) {
			snd_trident_synth_free_private_instruments(p, ev->data.addr.client);
			return 0;
		}
	}
	if (direct) {
		if (ev->type >= SNDRV_SEQ_EVENT_INSTR_BEGIN) {
			snd_seq_instr_event(&p->trident->synth.simple_ops.kops,
					    p->trident->synth.ilist, ev,
					    p->trident->synth.seq_client, atomic, hop);
			return 0;
		}
	}
	return 0;
}

static void snd_trident_synth_instr_notify(void *private_data,
					   struct snd_seq_kinstr * instr,
					   int what)
{
	int idx;
	struct snd_trident *trident = private_data;
	struct snd_trident_voice *pvoice;
	unsigned long flags;

	spin_lock_irqsave(&trident->event_lock, flags);
	for (idx = 0; idx < 64; idx++) {
		pvoice = &trident->synth.voices[idx];
		if (pvoice->use && !memcmp(&pvoice->instr, &instr->instr, sizeof(pvoice->instr))) {
			if (pvoice->sample_ops && pvoice->sample_ops->sample_stop) {
				pvoice->sample_ops->sample_stop(trident, pvoice, SAMPLE_STOP_IMMEDIATELY);
			} else {
				snd_trident_stop_voice(trident, pvoice->number);
				pvoice->flags &= ~SNDRV_TRIDENT_VFLG_RUNNING;
			}
		}
	}
	spin_unlock_irqrestore(&trident->event_lock, flags);
}

/*

 */

static void snd_trident_synth_free_port(void *private_data)
{
	struct snd_trident_port *p = (struct snd_trident_port *) private_data;

	if (p)
		snd_midi_channel_free_set(p->chset);
}

static int snd_trident_synth_create_port(struct snd_trident * trident, int idx)
{
	struct snd_trident_port *p;
	struct snd_seq_port_callback callbacks;
	char name[32];
	char *str;
	int result;

	p = &trident->synth.seq_ports[idx];
	p->chset = snd_midi_channel_alloc_set(16);
	if (p->chset == NULL)
		return -ENOMEM;
	p->chset->private_data = p;
	p->trident = trident;
	p->client = trident->synth.seq_client;

	memset(&callbacks, 0, sizeof(callbacks));
	callbacks.owner = THIS_MODULE;
	callbacks.use = snd_trident_synth_use;
	callbacks.unuse = snd_trident_synth_unuse;
	callbacks.event_input = snd_trident_synth_event_input;
	callbacks.private_free = snd_trident_synth_free_port;
	callbacks.private_data = p;

	str = "???";
	switch (trident->device) {
	case TRIDENT_DEVICE_ID_DX:	str = "Trident 4DWave-DX"; break;
	case TRIDENT_DEVICE_ID_NX:	str = "Trident 4DWave-NX"; break;
	case TRIDENT_DEVICE_ID_SI7018:	str = "SiS 7018"; break;
	}
	sprintf(name, "%s port %i", str, idx);
	p->chset->port = snd_seq_event_port_attach(trident->synth.seq_client,
						   &callbacks,
						   SNDRV_SEQ_PORT_CAP_WRITE | SNDRV_SEQ_PORT_CAP_SUBS_WRITE,
						   SNDRV_SEQ_PORT_TYPE_DIRECT_SAMPLE |
						   SNDRV_SEQ_PORT_TYPE_SYNTH |
						   SNDRV_SEQ_PORT_TYPE_HARDWARE |
						   SNDRV_SEQ_PORT_TYPE_SYNTHESIZER,
						   16, 0,
						   name);
	if (p->chset->port < 0) {
		result = p->chset->port;
		snd_trident_synth_free_port(p);
		return result;
	}
	p->port = p->chset->port;
	return 0;
}

/*

 */

static int snd_trident_synth_new_device(struct snd_seq_device *dev)
{
	struct snd_trident *trident;
	int client, i;
	struct snd_seq_port_subscribe sub;
	struct snd_simple_ops *simpleops;
	char *str;

	trident = *(struct snd_trident **)SNDRV_SEQ_DEVICE_ARGPTR(dev);
	if (trident == NULL)
		return -EINVAL;

	trident->synth.seq_client = -1;

	/* allocate new client */
	str = "???";
	switch (trident->device) {
	case TRIDENT_DEVICE_ID_DX:	str = "Trident 4DWave-DX"; break;
	case TRIDENT_DEVICE_ID_NX:	str = "Trident 4DWave-NX"; break;
	case TRIDENT_DEVICE_ID_SI7018:	str = "SiS 7018"; break;
	}
	client = trident->synth.seq_client =
		snd_seq_create_kernel_client(trident->card, 1, str);
	if (client < 0)
		return client;

	for (i = 0; i < 4; i++)
		snd_trident_synth_create_port(trident, i);

	trident->synth.ilist = snd_seq_instr_list_new();
	if (trident->synth.ilist == NULL) {
		snd_seq_delete_kernel_client(client);
		trident->synth.seq_client = -1;
		return -ENOMEM;
	}
	trident->synth.ilist->flags = SNDRV_SEQ_INSTR_FLG_DIRECT;

	simpleops = &trident->synth.simple_ops;
	snd_seq_simple_init(simpleops, trident, NULL);
	simpleops->put_sample = snd_trident_simple_put_sample;
	simpleops->get_sample = snd_trident_simple_get_sample;
	simpleops->remove_sample = snd_trident_simple_remove_sample;
	simpleops->notify = snd_trident_synth_instr_notify;

	memset(&sub, 0, sizeof(sub));
	sub.sender.client = SNDRV_SEQ_CLIENT_SYSTEM;
	sub.sender.port = SNDRV_SEQ_PORT_SYSTEM_ANNOUNCE;
	sub.dest.client = client;
	sub.dest.port = 0;
	snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &sub);

	return 0;
}

static int snd_trident_synth_delete_device(struct snd_seq_device *dev)
{
	struct snd_trident *trident;

	trident = *(struct snd_trident **)SNDRV_SEQ_DEVICE_ARGPTR(dev);
	if (trident == NULL)
		return -EINVAL;

	if (trident->synth.seq_client >= 0) {
		snd_seq_delete_kernel_client(trident->synth.seq_client);
		trident->synth.seq_client = -1;
	}
	if (trident->synth.ilist)
		snd_seq_instr_list_free(&trident->synth.ilist);
	return 0;
}

static int __init alsa_trident_synth_init(void)
{
	static struct snd_seq_dev_ops ops =
	{
		snd_trident_synth_new_device,
		snd_trident_synth_delete_device
	};

	return snd_seq_device_register_driver(SNDRV_SEQ_DEV_ID_TRIDENT, &ops,
					      sizeof(struct snd_trident *));
}

static void __exit alsa_trident_synth_exit(void)
{
	snd_seq_device_unregister_driver(SNDRV_SEQ_DEV_ID_TRIDENT);
}

module_init(alsa_trident_synth_init)
module_exit(alsa_trident_synth_exit)