aboutsummaryrefslogtreecommitdiffstats
path: root/sound/pci/ac97/ac97_pcm.c
blob: c3e590bf7a02b4d4bebf3320e46a6f7594c940e8 (plain) (blame)
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
/*
 *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
 *  Universal interface for Audio Codec '97
 *
 *  For more details look to AC '97 component specification revision 2.2
 *  by Intel Corporation (http://developer.intel.com) and to datasheets
 *  for specific codecs.
 *
 *
 *   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/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/control.h>
#include <sound/ac97_codec.h>
#include <sound/asoundef.h>
#include "ac97_patch.h"
#include "ac97_id.h"
#include "ac97_local.h"

/*
 *  PCM support
 */

static unsigned char rate_reg_tables[2][4][9] = {
{
  /* standard rates */
  {
  	/* 3&4 front, 7&8 rear, 6&9 center/lfe */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 3 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 4 */
	0xff,				/* slot 5 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 6 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 7 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 8 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 9 */
	0xff,				/* slot 10 */
	0xff,				/* slot 11 */
  },
  {
  	/* 7&8 front, 6&9 rear, 10&11 center/lfe */
	0xff,				/* slot 3 */
	0xff,				/* slot 4 */
	0xff,				/* slot 5 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 6 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 7 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 8 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 9 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 10 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 11 */
  },
  {
  	/* 6&9 front, 10&11 rear, 3&4 center/lfe */
	AC97_PCM_LFE_DAC_RATE,		/* slot 3 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 4 */
	0xff,				/* slot 5 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 6 */
	0xff,				/* slot 7 */
	0xff,				/* slot 8 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 9 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 10 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 11 */
  },
  {
  	/* 10&11 front, 3&4 rear, 7&8 center/lfe */
	AC97_PCM_SURR_DAC_RATE,		/* slot 3 */
	AC97_PCM_SURR_DAC_RATE,		/* slot 4 */
	0xff,				/* slot 5 */
	0xff,				/* slot 6 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 7 */
	AC97_PCM_LFE_DAC_RATE,		/* slot 8 */
	0xff,				/* slot 9 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 10 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 11 */
  },
},
{
  /* double rates */
  {
  	/* 3&4 front, 7&8 front (t+1) */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 3 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 4 */
	0xff,				/* slot 5 */
	0xff,				/* slot 6 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 7 */
	AC97_PCM_FRONT_DAC_RATE,	/* slot 8 */
	0xff,				/* slot 9 */
	0xff,				/* slot 10 */
	0xff,				/* slot 11 */
  },
  {
	/* not specified in the specification */
	0xff,				/* slot 3 */
	0xff,				/* slot 4 */
	0xff,				/* slot 5 */
	0xff,				/* slot 6 */
	0xff,				/* slot 7 */
	0xff,				/* slot 8 */
	0xff,				/* slot 9 */
	0xff,				/* slot 10 */
	0xff,				/* slot 11 */
  },
  {
	0xff,				/* slot 3 */
	0xff,				/* slot 4 */
	0xff,				/* slot 5 */
	0xff,				/* slot 6 */
	0xff,				/* slot 7 */
	0xff,				/* slot 8 */
	0xff,				/* slot 9 */
	0xff,				/* slot 10 */
	0xff,				/* slot 11 */
  },
  {
	0xff,				/* slot 3 */
	0xff,				/* slot 4 */
	0xff,				/* slot 5 */
	0xff,				/* slot 6 */
	0xff,				/* slot 7 */
	0xff,				/* slot 8 */
	0xff,				/* slot 9 */
	0xff,				/* slot 10 */
	0xff,				/* slot 11 */
  }
}};

/* FIXME: more various mappings for ADC? */
static unsigned char rate_cregs[9] = {
	AC97_PCM_LR_ADC_RATE,	/* 3 */
	AC97_PCM_LR_ADC_RATE,	/* 4 */
	0xff,			/* 5 */
	AC97_PCM_MIC_ADC_RATE,	/* 6 */
	0xff,			/* 7 */
	0xff,			/* 8 */
	0xff,			/* 9 */
	0xff,			/* 10 */
	0xff,			/* 11 */
};

static unsigned char get_slot_reg(struct ac97_pcm *pcm, unsigned short cidx,
				  unsigned short slot, int dbl)
{
	if (slot < 3)
		return 0xff;
	if (slot > 11)
		return 0xff;
	if (pcm->spdif)
		return AC97_SPDIF; /* pseudo register */
	if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK)
		return rate_reg_tables[dbl][pcm->r[dbl].rate_table[cidx]][slot - 3];
	else
		return rate_cregs[slot - 3];
}

static int set_spdif_rate(struct snd_ac97 *ac97, unsigned short rate)
{
	unsigned short old, bits, reg, mask;
	unsigned int sbits;

	if (! (ac97->ext_id & AC97_EI_SPDIF))
		return -ENODEV;

	/* TODO: double rate support */
	if (ac97->flags & AC97_CS_SPDIF) {
		switch (rate) {
		case 48000: bits = 0; break;
		case 44100: bits = 1 << AC97_SC_SPSR_SHIFT; break;
		default: /* invalid - disable output */
			snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
			return -EINVAL;
		}
		reg = AC97_CSR_SPDIF;
		mask = 1 << AC97_SC_SPSR_SHIFT;
	} else {
		if (ac97->id == AC97_ID_CM9739 && rate != 48000) {
			snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
			return -EINVAL;
		}
		switch (rate) {
		case 44100: bits = AC97_SC_SPSR_44K; break;
		case 48000: bits = AC97_SC_SPSR_48K; break;
		case 32000: bits = AC97_SC_SPSR_32K; break;
		default: /* invalid - disable output */
			snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
			return -EINVAL;
		}
		reg = AC97_SPDIF;
		mask = AC97_SC_SPSR_MASK;
	}

	down(&ac97->reg_mutex);
	old = snd_ac97_read(ac97, reg) & mask;
	if (old != bits) {
		snd_ac97_update_bits_nolock(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
		snd_ac97_update_bits_nolock(ac97, reg, mask, bits);
		/* update the internal spdif bits */
		sbits = ac97->spdif_status;
		if (sbits & IEC958_AES0_PROFESSIONAL) {
			sbits &= ~IEC958_AES0_PRO_FS;
			switch (rate) {
			case 44100: sbits |= IEC958_AES0_PRO_FS_44100; break;
			case 48000: sbits |= IEC958_AES0_PRO_FS_48000; break;
			case 32000: sbits |= IEC958_AES0_PRO_FS_32000; break;
			}
		} else {
			sbits &= ~(IEC958_AES3_CON_FS << 24);
			switch (rate) {
			case 44100: sbits |= IEC958_AES3_CON_FS_44100<<24; break;
			case 48000: sbits |= IEC958_AES3_CON_FS_48000<<24; break;
			case 32000: sbits |= IEC958_AES3_CON_FS_32000<<24; break;
			}
		}
		ac97->spdif_status = sbits;
	}
	snd_ac97_update_bits_nolock(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, AC97_EA_SPDIF);
	up(&ac97->reg_mutex);
	return 0;
}

/**
 * snd_ac97_set_rate - change the rate of the given input/output.
 * @ac97: the ac97 instance
 * @reg: the register to change
 * @rate: the sample rate to set
 *
 * Changes the rate of the given input/output on the codec.
 * If the codec doesn't support VAR, the rate must be 48000 (except
 * for SPDIF).
 *
 * The valid registers are AC97_PMC_MIC_ADC_RATE,
 * AC97_PCM_FRONT_DAC_RATE, AC97_PCM_LR_ADC_RATE.
 * AC97_PCM_SURR_DAC_RATE and AC97_PCM_LFE_DAC_RATE are accepted
 * if the codec supports them.
 * AC97_SPDIF is accepted as a pseudo register to modify the SPDIF
 * status bits.
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_ac97_set_rate(struct snd_ac97 *ac97, int reg, unsigned int rate)
{
	int dbl;
	unsigned int tmp;
	
	dbl = rate > 48000;
	if (dbl) {
		if (!(ac97->flags & AC97_DOUBLE_RATE))
			return -EINVAL;
		if (reg != AC97_PCM_FRONT_DAC_RATE)
			return -EINVAL;
	}

	switch (reg) {
	case AC97_PCM_MIC_ADC_RATE:
		if ((ac97->regs[AC97_EXTENDED_STATUS] & AC97_EA_VRM) == 0)	/* MIC VRA */
			if (rate != 48000)
				return -EINVAL;
		break;
	case AC97_PCM_FRONT_DAC_RATE:
	case AC97_PCM_LR_ADC_RATE:
		if ((ac97->regs[AC97_EXTENDED_STATUS] & AC97_EA_VRA) == 0)	/* VRA */
			if (rate != 48000 && rate != 96000)
				return -EINVAL;
		break;
	case AC97_PCM_SURR_DAC_RATE:
		if (! (ac97->scaps & AC97_SCAP_SURROUND_DAC))
			return -EINVAL;
		break;
	case AC97_PCM_LFE_DAC_RATE:
		if (! (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
			return -EINVAL;
		break;
	case AC97_SPDIF:
		/* special case */
		return set_spdif_rate(ac97, rate);
	default:
		return -EINVAL;
	}
	if (dbl)
		rate /= 2;
	tmp = (rate * ac97->bus->clock) / 48000;
	if (tmp > 65535)
		return -EINVAL;
	if ((ac97->ext_id & AC97_EI_DRA) && reg == AC97_PCM_FRONT_DAC_RATE)
		snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS,
				     AC97_EA_DRA, dbl ? AC97_EA_DRA : 0);
	snd_ac97_update(ac97, reg, tmp & 0xffff);
	snd_ac97_read(ac97, reg);
	if ((ac97->ext_id & AC97_EI_DRA) && reg == AC97_PCM_FRONT_DAC_RATE) {
		/* Intel controllers require double rate data to be put in
		 * slots 7+8
		 */
		snd_ac97_update_bits(ac97, AC97_GENERAL_PURPOSE,
				     AC97_GP_DRSS_MASK,
				     dbl ? AC97_GP_DRSS_78 : 0);
		snd_ac97_read(ac97, AC97_GENERAL_PURPOSE);
	}
	return 0;
}

static unsigned short get_pslots(struct snd_ac97 *ac97, unsigned char *rate_table, unsigned short *spdif_slots)
{
	if (!ac97_is_audio(ac97))
		return 0;
	if (ac97_is_rev22(ac97) || ac97_can_amap(ac97)) {
		unsigned short slots = 0;
		if (ac97_is_rev22(ac97)) {
			/* Note: it's simply emulation of AMAP behaviour */
			u16 es;
			es = ac97->regs[AC97_EXTENDED_ID] &= ~AC97_EI_DACS_SLOT_MASK;
			switch (ac97->addr) {
			case 1:
			case 2: es |= (1<<AC97_EI_DACS_SLOT_SHIFT); break;
			case 3: es |= (2<<AC97_EI_DACS_SLOT_SHIFT); break;
			}
			snd_ac97_write_cache(ac97, AC97_EXTENDED_ID, es);
		}
		switch (ac97->addr) {
		case 0:
			slots |= (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
			if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
				slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
			if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
				slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
			if (ac97->ext_id & AC97_EI_SPDIF) {
				if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
					*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT)|(1<<AC97_SLOT_SPDIF_RIGHT);
				else if (!(ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
					*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
				else
					*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
			}
			*rate_table = 0;
			break;
		case 1:
		case 2:
			slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
			if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
				slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
			if (ac97->ext_id & AC97_EI_SPDIF) {
				if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
					*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
				else
					*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
			}
			*rate_table = 1;
			break;
		case 3:
			slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
			if (ac97->ext_id & AC97_EI_SPDIF)
				*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
			*rate_table = 2;
			break;
		}
		return slots;
	} else {
		unsigned short slots;
		slots = (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
		if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
			slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
		if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
			slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
		if (ac97->ext_id & AC97_EI_SPDIF) {
			if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
				*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT)|(1<<AC97_SLOT_SPDIF_RIGHT);
			else if (!(ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
				*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
			else
				*spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
		}
		*rate_table = 0;
		return slots;
	}
}

static unsigned short get_cslots(struct snd_ac97 *ac97)
{
	unsigned short slots;

	if (!ac97_is_audio(ac97))
		return 0;
	slots = (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
	slots |= (1<<AC97_SLOT_MIC);
	return slots;
}

static unsigned int get_rates(struct ac97_pcm *pcm, unsigned int cidx, unsigned short slots, int dbl)
{
	int i, idx;
	unsigned int rates = ~0;
	unsigned char reg;

	for (i = 3; i < 12; i++) {
		if (!(slots & (1 << i)))
			continue;
		reg = get_slot_reg(pcm, cidx, i, dbl);
		switch (reg) {
		case AC97_PCM_FRONT_DAC_RATE:	idx = AC97_RATES_FRONT_DAC; break;
		case AC97_PCM_SURR_DAC_RATE:	idx = AC97_RATES_SURR_DAC; break;
		case AC97_PCM_LFE_DAC_RATE:	idx = AC97_RATES_LFE_DAC; break;
		case AC97_PCM_LR_ADC_RATE:	idx = AC97_RATES_ADC; break;
		case AC97_PCM_MIC_ADC_RATE:	idx = AC97_RATES_MIC_ADC; break;
		default:			idx = AC97_RATES_SPDIF; break;
		}
		rates &= pcm->r[dbl].codec[cidx]->rates[idx];
	}
	if (!dbl)
		rates &= ~(SNDRV_PCM_RATE_64000 | SNDRV_PCM_RATE_88200 |
			   SNDRV_PCM_RATE_96000);
	return rates;
}

/**
 * snd_ac97_pcm_assign - assign AC97 slots to given PCM streams
 * @bus: the ac97 bus instance
 * @pcms_count: count of PCMs to be assigned
 * @pcms: PCMs to be assigned
 *
 * It assigns available AC97 slots for given PCMs. If none or only
 * some slots are available, pcm->xxx.slots and pcm->xxx.rslots[] members
 * are reduced and might be zero.
 */
int snd_ac97_pcm_assign(struct snd_ac97_bus *bus,
			unsigned short pcms_count,
			const struct ac97_pcm *pcms)
{
	int i, j, k;
	const struct ac97_pcm *pcm;
	struct ac97_pcm *rpcms, *rpcm;
	unsigned short avail_slots[2][4];
	unsigned char rate_table[2][4];
	unsigned short tmp, slots;
	unsigned short spdif_slots[4];
	unsigned int rates;
	struct snd_ac97 *codec;

	rpcms = kcalloc(pcms_count, sizeof(struct ac97_pcm), GFP_KERNEL);
	if (rpcms == NULL)
		return -ENOMEM;
	memset(avail_slots, 0, sizeof(avail_slots));
	memset(rate_table, 0, sizeof(rate_table));
	memset(spdif_slots, 0, sizeof(spdif_slots));
	for (i = 0; i < 4; i++) {
		codec = bus->codec[i];
		if (!codec)
			continue;
		avail_slots[0][i] = get_pslots(codec, &rate_table[0][i], &spdif_slots[i]);
		avail_slots[1][i] = get_cslots(codec);
		if (!(codec->scaps & AC97_SCAP_INDEP_SDIN)) {
			for (j = 0; j < i; j++) {
				if (bus->codec[j])
					avail_slots[1][i] &= ~avail_slots[1][j];
			}
		}
	}
	/* first step - exclusive devices */
	for (i = 0; i < pcms_count; i++) {
		pcm = &pcms[i];
		rpcm = &rpcms[i];
		/* low-level driver thinks that it's more clever */
		if (pcm->copy_flag) {
			*rpcm = *pcm;
			continue;
		}
		rpcm->stream = pcm->stream;
		rpcm->exclusive = pcm->exclusive;
		rpcm->spdif = pcm->spdif;
		rpcm->private_value = pcm->private_value;
		rpcm->bus = bus;
		rpcm->rates = ~0;
		slots = pcm->r[0].slots;
		for (j = 0; j < 4 && slots; j++) {
			if (!bus->codec[j])
				continue;
			rates = ~0;
			if (pcm->spdif && pcm->stream == 0)
				tmp = spdif_slots[j];
			else
				tmp = avail_slots[pcm->stream][j];
			if (pcm->exclusive) {
				/* exclusive access */
				tmp &= slots;
				for (k = 0; k < i; k++) {
					if (rpcm->stream == rpcms[k].stream)
						tmp &= ~rpcms[k].r[0].rslots[j];
				}
			} else {
				/* non-exclusive access */
				tmp &= pcm->r[0].slots;
			}
			if (tmp) {
				rpcm->r[0].rslots[j] = tmp;
				rpcm->r[0].codec[j] = bus->codec[j];
				rpcm->r[0].rate_table[j] = rate_table[pcm->stream][j];
				if (bus->no_vra)
					rates = SNDRV_PCM_RATE_48000;
				else
					rates = get_rates(rpcm, j, tmp, 0);
				if (pcm->exclusive)
					avail_slots[pcm->stream][j] &= ~tmp;
			}
			slots &= ~tmp;
			rpcm->r[0].slots |= tmp;
			rpcm->rates &= rates;
		}
		/* for double rate, we check the first codec only */
		if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK &&
		    bus->codec[0] && (bus->codec[0]->flags & AC97_DOUBLE_RATE) &&
		    rate_table[pcm->stream][0] == 0) {
			tmp = (1<<AC97_SLOT_PCM_LEFT) | (1<<AC97_SLOT_PCM_RIGHT) |
			      (1<<AC97_SLOT_PCM_LEFT_0) | (1<<AC97_SLOT_PCM_RIGHT_0);
			if ((tmp & pcm->r[1].slots) == tmp) {
				rpcm->r[1].slots = tmp;
				rpcm->r[1].rslots[0] = tmp;
				rpcm->r[1].rate_table[0] = 0;
				rpcm->r[1].codec[0] = bus->codec[0];
				if (pcm->exclusive)
					avail_slots[pcm->stream][0] &= ~tmp;
				if (bus->no_vra)
					rates = SNDRV_PCM_RATE_96000;
				else
					rates = get_rates(rpcm, 0, tmp, 1);
				rpcm->rates |= rates;
			}
		}
		if (rpcm->rates == ~0)
			rpcm->rates = 0; /* not used */
	}
	bus->pcms_count = pcms_count;
	bus->pcms = rpcms;
	return 0;
}

/**
 * snd_ac97_pcm_open - opens the given AC97 pcm
 * @pcm: the ac97 pcm instance
 * @rate: rate in Hz, if codec does not support VRA, this value must be 48000Hz
 * @cfg: output stream characteristics
 * @slots: a subset of allocated slots (snd_ac97_pcm_assign) for this pcm
 *
 * It locks the specified slots and sets the given rate to AC97 registers.
 */
int snd_ac97_pcm_open(struct ac97_pcm *pcm, unsigned int rate,
		      enum ac97_pcm_cfg cfg, unsigned short slots)
{
	struct snd_ac97_bus *bus;
	int i, cidx, r, ok_flag;
	unsigned int reg_ok[4] = {0,0,0,0};
	unsigned char reg;
	int err = 0;

	r = rate > 48000;
	bus = pcm->bus;
	if (cfg == AC97_PCM_CFG_SPDIF) {
		int err;
		for (cidx = 0; cidx < 4; cidx++)
			if (bus->codec[cidx] && (bus->codec[cidx]->ext_id & AC97_EI_SPDIF)) {
				err = set_spdif_rate(bus->codec[cidx], rate);
				if (err < 0)
					return err;
			}
	}
	spin_lock_irq(&pcm->bus->bus_lock);
	for (i = 3; i < 12; i++) {
		if (!(slots & (1 << i)))
			continue;
		ok_flag = 0;
		for (cidx = 0; cidx < 4; cidx++) {
			if (bus->used_slots[pcm->stream][cidx] & (1 << i)) {
				spin_unlock_irq(&pcm->bus->bus_lock);
				err = -EBUSY;
				goto error;
			}
			if (pcm->r[r].rslots[cidx] & (1 << i)) {
				bus->used_slots[pcm->stream][cidx] |= (1 << i);
				ok_flag++;
			}
		}
		if (!ok_flag) {
			spin_unlock_irq(&pcm->bus->bus_lock);
			snd_printk(KERN_ERR "cannot find configuration for AC97 slot %i\n", i);
			err = -EAGAIN;
			goto error;
		}
	}
	spin_unlock_irq(&pcm->bus->bus_lock);
	for (i = 3; i < 12; i++) {
		if (!(slots & (1 << i)))
			continue;
		for (cidx = 0; cidx < 4; cidx++) {
			if (pcm->r[r].rslots[cidx] & (1 << i)) {
				reg = get_slot_reg(pcm, cidx, i, r);
				if (reg == 0xff) {
					snd_printk(KERN_ERR "invalid AC97 slot %i?\n", i);
					continue;
				}
				if (reg_ok[cidx] & (1 << (reg - AC97_PCM_FRONT_DAC_RATE)))
					continue;
				//printk(KERN_DEBUG "setting ac97 reg 0x%x to rate %d\n", reg, rate);
				err = snd_ac97_set_rate(pcm->r[r].codec[cidx], reg, rate);
				if (err < 0)
					snd_printk(KERN_ERR "error in snd_ac97_set_rate: cidx=%d, reg=0x%x, rate=%d, err=%d\n", cidx, reg, rate, err);
				else
					reg_ok[cidx] |= (1 << (reg - AC97_PCM_FRONT_DAC_RATE));
			}
		}
	}
	pcm->aslots = slots;
	return 0;

 error:
	pcm->aslots = slots;
	snd_ac97_pcm_close(pcm);
	return err;
}

/**
 * snd_ac97_pcm_close - closes the given AC97 pcm
 * @pcm: the ac97 pcm instance
 *
 * It frees the locked AC97 slots.
 */
int snd_ac97_pcm_close(struct ac97_pcm *pcm)
{
	struct snd_ac97_bus *bus;
	unsigned short slots = pcm->aslots;
	int i, cidx;

	bus = pcm->bus;
	spin_lock_irq(&pcm->bus->bus_lock);
	for (i = 3; i < 12; i++) {
		if (!(slots & (1 << i)))
			continue;
		for (cidx = 0; cidx < 4; cidx++)
			bus->used_slots[pcm->stream][cidx] &= ~(1 << i);
	}
	pcm->aslots = 0;
	spin_unlock_irq(&pcm->bus->bus_lock);
	return 0;
}

static int double_rate_hw_constraint_rate(struct snd_pcm_hw_params *params,
					  struct snd_pcm_hw_rule *rule)
{
	struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	if (channels->min > 2) {
		static const struct snd_interval single_rates = {
			.min = 1,
			.max = 48000,
		};
		struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
		return snd_interval_refine(rate, &single_rates);
	}
	return 0;
}

static int double_rate_hw_constraint_channels(struct snd_pcm_hw_params *params,
					      struct snd_pcm_hw_rule *rule)
{
	struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	if (rate->min > 48000) {
		static const struct snd_interval double_rate_channels = {
			.min = 2,
			.max = 2,
		};
		struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
		return snd_interval_refine(channels, &double_rate_channels);
	}
	return 0;
}

/**
 * snd_ac97_pcm_double_rate_rules - set double rate constraints
 * @runtime: the runtime of the ac97 front playback pcm
 *
 * Installs the hardware constraint rules to prevent using double rates and
 * more than two channels at the same time.
 */
int snd_ac97_pcm_double_rate_rules(struct snd_pcm_runtime *runtime)
{
	int err;

	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
				  double_rate_hw_constraint_rate, NULL,
				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
				  double_rate_hw_constraint_channels, NULL,
				  SNDRV_PCM_HW_PARAM_RATE, -1);
	return err;
}