1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 * Universal interface for Audio Codec '97
6 * For more details look to AC '97 component specification revision 2.2
7 * by Intel Corporation (http://developer.intel.com) and to datasheets
11 #include <linux/delay.h>
12 #include <linux/init.h>
13 #include <linux/slab.h>
14 #include <linux/mutex.h>
15 #include <linux/export.h>
17 #include <sound/core.h>
18 #include <sound/pcm.h>
19 #include <sound/control.h>
20 #include <sound/ac97_codec.h>
21 #include <sound/asoundef.h>
23 #include "ac97_local.h"
29 static const unsigned char rate_reg_tables[2][4][9] = {
33 /* 3&4 front, 7&8 rear, 6&9 center/lfe */
34 AC97_PCM_FRONT_DAC_RATE, /* slot 3 */
35 AC97_PCM_FRONT_DAC_RATE, /* slot 4 */
37 AC97_PCM_LFE_DAC_RATE, /* slot 6 */
38 AC97_PCM_SURR_DAC_RATE, /* slot 7 */
39 AC97_PCM_SURR_DAC_RATE, /* slot 8 */
40 AC97_PCM_LFE_DAC_RATE, /* slot 9 */
45 /* 7&8 front, 6&9 rear, 10&11 center/lfe */
49 AC97_PCM_SURR_DAC_RATE, /* slot 6 */
50 AC97_PCM_FRONT_DAC_RATE, /* slot 7 */
51 AC97_PCM_FRONT_DAC_RATE, /* slot 8 */
52 AC97_PCM_SURR_DAC_RATE, /* slot 9 */
53 AC97_PCM_LFE_DAC_RATE, /* slot 10 */
54 AC97_PCM_LFE_DAC_RATE, /* slot 11 */
57 /* 6&9 front, 10&11 rear, 3&4 center/lfe */
58 AC97_PCM_LFE_DAC_RATE, /* slot 3 */
59 AC97_PCM_LFE_DAC_RATE, /* slot 4 */
61 AC97_PCM_FRONT_DAC_RATE, /* slot 6 */
64 AC97_PCM_FRONT_DAC_RATE, /* slot 9 */
65 AC97_PCM_SURR_DAC_RATE, /* slot 10 */
66 AC97_PCM_SURR_DAC_RATE, /* slot 11 */
69 /* 10&11 front, 3&4 rear, 7&8 center/lfe */
70 AC97_PCM_SURR_DAC_RATE, /* slot 3 */
71 AC97_PCM_SURR_DAC_RATE, /* slot 4 */
74 AC97_PCM_LFE_DAC_RATE, /* slot 7 */
75 AC97_PCM_LFE_DAC_RATE, /* slot 8 */
77 AC97_PCM_FRONT_DAC_RATE, /* slot 10 */
78 AC97_PCM_FRONT_DAC_RATE, /* slot 11 */
84 /* 3&4 front, 7&8 front (t+1) */
85 AC97_PCM_FRONT_DAC_RATE, /* slot 3 */
86 AC97_PCM_FRONT_DAC_RATE, /* slot 4 */
89 AC97_PCM_FRONT_DAC_RATE, /* slot 7 */
90 AC97_PCM_FRONT_DAC_RATE, /* slot 8 */
96 /* not specified in the specification */
131 /* FIXME: more various mappings for ADC? */
132 static const unsigned char rate_cregs[9] = {
133 AC97_PCM_LR_ADC_RATE, /* 3 */
134 AC97_PCM_LR_ADC_RATE, /* 4 */
136 AC97_PCM_MIC_ADC_RATE, /* 6 */
144 static unsigned char get_slot_reg(struct ac97_pcm *pcm, unsigned short cidx,
145 unsigned short slot, int dbl)
152 return AC97_SPDIF; /* pseudo register */
153 if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK)
154 return rate_reg_tables[dbl][pcm->r[dbl].rate_table[cidx]][slot - 3];
156 return rate_cregs[slot - 3];
159 static int set_spdif_rate(struct snd_ac97 *ac97, unsigned short rate)
161 unsigned short old, bits, reg, mask;
164 if (! (ac97->ext_id & AC97_EI_SPDIF))
167 /* TODO: double rate support */
168 if (ac97->flags & AC97_CS_SPDIF) {
170 case 48000: bits = 0; break;
171 case 44100: bits = 1 << AC97_SC_SPSR_SHIFT; break;
172 default: /* invalid - disable output */
173 snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
176 reg = AC97_CSR_SPDIF;
177 mask = 1 << AC97_SC_SPSR_SHIFT;
179 if (ac97->id == AC97_ID_CM9739 && rate != 48000) {
180 snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
184 case 44100: bits = AC97_SC_SPSR_44K; break;
185 case 48000: bits = AC97_SC_SPSR_48K; break;
186 case 32000: bits = AC97_SC_SPSR_32K; break;
187 default: /* invalid - disable output */
188 snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
192 mask = AC97_SC_SPSR_MASK;
195 mutex_lock(&ac97->reg_mutex);
196 old = snd_ac97_read(ac97, reg) & mask;
198 snd_ac97_update_bits_nolock(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, 0);
199 snd_ac97_update_bits_nolock(ac97, reg, mask, bits);
200 /* update the internal spdif bits */
201 sbits = ac97->spdif_status;
202 if (sbits & IEC958_AES0_PROFESSIONAL) {
203 sbits &= ~IEC958_AES0_PRO_FS;
205 case 44100: sbits |= IEC958_AES0_PRO_FS_44100; break;
206 case 48000: sbits |= IEC958_AES0_PRO_FS_48000; break;
207 case 32000: sbits |= IEC958_AES0_PRO_FS_32000; break;
210 sbits &= ~(IEC958_AES3_CON_FS << 24);
212 case 44100: sbits |= IEC958_AES3_CON_FS_44100<<24; break;
213 case 48000: sbits |= IEC958_AES3_CON_FS_48000<<24; break;
214 case 32000: sbits |= IEC958_AES3_CON_FS_32000<<24; break;
217 ac97->spdif_status = sbits;
219 snd_ac97_update_bits_nolock(ac97, AC97_EXTENDED_STATUS, AC97_EA_SPDIF, AC97_EA_SPDIF);
220 mutex_unlock(&ac97->reg_mutex);
225 * snd_ac97_set_rate - change the rate of the given input/output.
226 * @ac97: the ac97 instance
227 * @reg: the register to change
228 * @rate: the sample rate to set
230 * Changes the rate of the given input/output on the codec.
231 * If the codec doesn't support VAR, the rate must be 48000 (except
234 * The valid registers are AC97_PCM_MIC_ADC_RATE,
235 * AC97_PCM_FRONT_DAC_RATE, AC97_PCM_LR_ADC_RATE.
236 * AC97_PCM_SURR_DAC_RATE and AC97_PCM_LFE_DAC_RATE are accepted
237 * if the codec supports them.
238 * AC97_SPDIF is accepted as a pseudo register to modify the SPDIF
241 * Return: Zero if successful, or a negative error code on failure.
243 int snd_ac97_set_rate(struct snd_ac97 *ac97, int reg, unsigned int rate)
250 if (!(ac97->flags & AC97_DOUBLE_RATE))
252 if (reg != AC97_PCM_FRONT_DAC_RATE)
256 snd_ac97_update_power(ac97, reg, 1);
258 case AC97_PCM_MIC_ADC_RATE:
259 if ((ac97->regs[AC97_EXTENDED_STATUS] & AC97_EA_VRM) == 0) /* MIC VRA */
263 case AC97_PCM_FRONT_DAC_RATE:
264 case AC97_PCM_LR_ADC_RATE:
265 if ((ac97->regs[AC97_EXTENDED_STATUS] & AC97_EA_VRA) == 0) /* VRA */
266 if (rate != 48000 && rate != 96000)
269 case AC97_PCM_SURR_DAC_RATE:
270 if (! (ac97->scaps & AC97_SCAP_SURROUND_DAC))
273 case AC97_PCM_LFE_DAC_RATE:
274 if (! (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
279 return set_spdif_rate(ac97, rate);
285 tmp = (rate * ac97->bus->clock) / 48000;
288 if ((ac97->ext_id & AC97_EI_DRA) && reg == AC97_PCM_FRONT_DAC_RATE)
289 snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS,
290 AC97_EA_DRA, dbl ? AC97_EA_DRA : 0);
291 snd_ac97_update(ac97, reg, tmp & 0xffff);
292 snd_ac97_read(ac97, reg);
293 if ((ac97->ext_id & AC97_EI_DRA) && reg == AC97_PCM_FRONT_DAC_RATE) {
294 /* Intel controllers require double rate data to be put in
297 snd_ac97_update_bits(ac97, AC97_GENERAL_PURPOSE,
299 dbl ? AC97_GP_DRSS_78 : 0);
300 snd_ac97_read(ac97, AC97_GENERAL_PURPOSE);
305 EXPORT_SYMBOL(snd_ac97_set_rate);
307 static unsigned short get_pslots(struct snd_ac97 *ac97, unsigned char *rate_table, unsigned short *spdif_slots)
309 if (!ac97_is_audio(ac97))
311 if (ac97_is_rev22(ac97) || ac97_can_amap(ac97)) {
312 unsigned short slots = 0;
313 if (ac97_is_rev22(ac97)) {
314 /* Note: it's simply emulation of AMAP behaviour */
316 es = ac97->regs[AC97_EXTENDED_ID] &= ~AC97_EI_DACS_SLOT_MASK;
317 switch (ac97->addr) {
319 case 2: es |= (1<<AC97_EI_DACS_SLOT_SHIFT); break;
320 case 3: es |= (2<<AC97_EI_DACS_SLOT_SHIFT); break;
322 snd_ac97_write_cache(ac97, AC97_EXTENDED_ID, es);
324 switch (ac97->addr) {
326 slots |= (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
327 if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
328 slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
329 if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
330 slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
331 if (ac97->ext_id & AC97_EI_SPDIF) {
332 if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
333 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT)|(1<<AC97_SLOT_SPDIF_RIGHT);
334 else if (!(ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
335 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
337 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
343 slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
344 if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
345 slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
346 if (ac97->ext_id & AC97_EI_SPDIF) {
347 if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
348 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
350 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
355 slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
356 if (ac97->ext_id & AC97_EI_SPDIF)
357 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
363 unsigned short slots;
364 slots = (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
365 if (ac97->scaps & AC97_SCAP_SURROUND_DAC)
366 slots |= (1<<AC97_SLOT_PCM_SLEFT)|(1<<AC97_SLOT_PCM_SRIGHT);
367 if (ac97->scaps & AC97_SCAP_CENTER_LFE_DAC)
368 slots |= (1<<AC97_SLOT_PCM_CENTER)|(1<<AC97_SLOT_LFE);
369 if (ac97->ext_id & AC97_EI_SPDIF) {
370 if (!(ac97->scaps & AC97_SCAP_SURROUND_DAC))
371 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT)|(1<<AC97_SLOT_SPDIF_RIGHT);
372 else if (!(ac97->scaps & AC97_SCAP_CENTER_LFE_DAC))
373 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT1)|(1<<AC97_SLOT_SPDIF_RIGHT1);
375 *spdif_slots = (1<<AC97_SLOT_SPDIF_LEFT2)|(1<<AC97_SLOT_SPDIF_RIGHT2);
382 static unsigned short get_cslots(struct snd_ac97 *ac97)
384 unsigned short slots;
386 if (!ac97_is_audio(ac97))
388 slots = (1<<AC97_SLOT_PCM_LEFT)|(1<<AC97_SLOT_PCM_RIGHT);
389 slots |= (1<<AC97_SLOT_MIC);
393 static unsigned int get_rates(struct ac97_pcm *pcm, unsigned int cidx, unsigned short slots, int dbl)
396 unsigned int rates = ~0;
399 for (i = 3; i < 12; i++) {
400 if (!(slots & (1 << i)))
402 reg = get_slot_reg(pcm, cidx, i, dbl);
404 case AC97_PCM_FRONT_DAC_RATE: idx = AC97_RATES_FRONT_DAC; break;
405 case AC97_PCM_SURR_DAC_RATE: idx = AC97_RATES_SURR_DAC; break;
406 case AC97_PCM_LFE_DAC_RATE: idx = AC97_RATES_LFE_DAC; break;
407 case AC97_PCM_LR_ADC_RATE: idx = AC97_RATES_ADC; break;
408 case AC97_PCM_MIC_ADC_RATE: idx = AC97_RATES_MIC_ADC; break;
409 default: idx = AC97_RATES_SPDIF; break;
411 rates &= pcm->r[dbl].codec[cidx]->rates[idx];
414 rates &= ~(SNDRV_PCM_RATE_64000 | SNDRV_PCM_RATE_88200 |
415 SNDRV_PCM_RATE_96000);
420 * snd_ac97_pcm_assign - assign AC97 slots to given PCM streams
421 * @bus: the ac97 bus instance
422 * @pcms_count: count of PCMs to be assigned
423 * @pcms: PCMs to be assigned
425 * It assigns available AC97 slots for given PCMs. If none or only
426 * some slots are available, pcm->xxx.slots and pcm->xxx.rslots[] members
427 * are reduced and might be zero.
429 * Return: Zero if successful, or a negative error code on failure.
431 int snd_ac97_pcm_assign(struct snd_ac97_bus *bus,
432 unsigned short pcms_count,
433 const struct ac97_pcm *pcms)
436 const struct ac97_pcm *pcm;
437 struct ac97_pcm *rpcms, *rpcm;
438 unsigned short avail_slots[2][4];
439 unsigned char rate_table[2][4];
440 unsigned short tmp, slots;
441 unsigned short spdif_slots[4];
443 struct snd_ac97 *codec;
445 rpcms = kcalloc(pcms_count, sizeof(struct ac97_pcm), GFP_KERNEL);
448 memset(avail_slots, 0, sizeof(avail_slots));
449 memset(rate_table, 0, sizeof(rate_table));
450 memset(spdif_slots, 0, sizeof(spdif_slots));
451 for (i = 0; i < 4; i++) {
452 codec = bus->codec[i];
455 avail_slots[0][i] = get_pslots(codec, &rate_table[0][i], &spdif_slots[i]);
456 avail_slots[1][i] = get_cslots(codec);
457 if (!(codec->scaps & AC97_SCAP_INDEP_SDIN)) {
458 for (j = 0; j < i; j++) {
460 avail_slots[1][i] &= ~avail_slots[1][j];
464 /* first step - exclusive devices */
465 for (i = 0; i < pcms_count; i++) {
468 /* low-level driver thinks that it's more clever */
469 if (pcm->copy_flag) {
473 rpcm->stream = pcm->stream;
474 rpcm->exclusive = pcm->exclusive;
475 rpcm->spdif = pcm->spdif;
476 rpcm->private_value = pcm->private_value;
479 slots = pcm->r[0].slots;
480 for (j = 0; j < 4 && slots; j++) {
484 if (pcm->spdif && pcm->stream == 0)
485 tmp = spdif_slots[j];
487 tmp = avail_slots[pcm->stream][j];
488 if (pcm->exclusive) {
489 /* exclusive access */
491 for (k = 0; k < i; k++) {
492 if (rpcm->stream == rpcms[k].stream)
493 tmp &= ~rpcms[k].r[0].rslots[j];
496 /* non-exclusive access */
497 tmp &= pcm->r[0].slots;
500 rpcm->r[0].rslots[j] = tmp;
501 rpcm->r[0].codec[j] = bus->codec[j];
502 rpcm->r[0].rate_table[j] = rate_table[pcm->stream][j];
504 rates = SNDRV_PCM_RATE_48000;
506 rates = get_rates(rpcm, j, tmp, 0);
508 avail_slots[pcm->stream][j] &= ~tmp;
511 rpcm->r[0].slots |= tmp;
512 rpcm->rates &= rates;
514 /* for double rate, we check the first codec only */
515 if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK &&
516 bus->codec[0] && (bus->codec[0]->flags & AC97_DOUBLE_RATE) &&
517 rate_table[pcm->stream][0] == 0) {
518 tmp = (1<<AC97_SLOT_PCM_LEFT) | (1<<AC97_SLOT_PCM_RIGHT) |
519 (1<<AC97_SLOT_PCM_LEFT_0) | (1<<AC97_SLOT_PCM_RIGHT_0);
520 if ((tmp & pcm->r[1].slots) == tmp) {
521 rpcm->r[1].slots = tmp;
522 rpcm->r[1].rslots[0] = tmp;
523 rpcm->r[1].rate_table[0] = 0;
524 rpcm->r[1].codec[0] = bus->codec[0];
526 avail_slots[pcm->stream][0] &= ~tmp;
528 rates = SNDRV_PCM_RATE_96000;
530 rates = get_rates(rpcm, 0, tmp, 1);
531 rpcm->rates |= rates;
534 if (rpcm->rates == ~0)
535 rpcm->rates = 0; /* not used */
537 bus->pcms_count = pcms_count;
542 EXPORT_SYMBOL(snd_ac97_pcm_assign);
545 * snd_ac97_pcm_open - opens the given AC97 pcm
546 * @pcm: the ac97 pcm instance
547 * @rate: rate in Hz, if codec does not support VRA, this value must be 48000Hz
548 * @cfg: output stream characteristics
549 * @slots: a subset of allocated slots (snd_ac97_pcm_assign) for this pcm
551 * It locks the specified slots and sets the given rate to AC97 registers.
553 * Return: Zero if successful, or a negative error code on failure.
555 int snd_ac97_pcm_open(struct ac97_pcm *pcm, unsigned int rate,
556 enum ac97_pcm_cfg cfg, unsigned short slots)
558 struct snd_ac97_bus *bus;
559 int i, cidx, r, ok_flag;
560 unsigned int reg_ok[4] = {0,0,0,0};
566 if (cfg == AC97_PCM_CFG_SPDIF) {
567 for (cidx = 0; cidx < 4; cidx++)
568 if (bus->codec[cidx] && (bus->codec[cidx]->ext_id & AC97_EI_SPDIF)) {
569 err = set_spdif_rate(bus->codec[cidx], rate);
574 spin_lock_irq(&pcm->bus->bus_lock);
575 for (i = 3; i < 12; i++) {
576 if (!(slots & (1 << i)))
579 for (cidx = 0; cidx < 4; cidx++) {
580 if (bus->used_slots[pcm->stream][cidx] & (1 << i)) {
581 spin_unlock_irq(&pcm->bus->bus_lock);
585 if (pcm->r[r].rslots[cidx] & (1 << i)) {
586 bus->used_slots[pcm->stream][cidx] |= (1 << i);
591 spin_unlock_irq(&pcm->bus->bus_lock);
592 dev_err(bus->card->dev,
593 "cannot find configuration for AC97 slot %i\n",
600 spin_unlock_irq(&pcm->bus->bus_lock);
601 for (i = 3; i < 12; i++) {
602 if (!(slots & (1 << i)))
604 for (cidx = 0; cidx < 4; cidx++) {
605 if (pcm->r[r].rslots[cidx] & (1 << i)) {
606 reg = get_slot_reg(pcm, cidx, i, r);
608 dev_err(bus->card->dev,
609 "invalid AC97 slot %i?\n", i);
612 if (reg_ok[cidx] & (1 << (reg - AC97_PCM_FRONT_DAC_RATE)))
614 dev_dbg(bus->card->dev,
615 "setting ac97 reg 0x%x to rate %d\n",
617 err = snd_ac97_set_rate(pcm->r[r].codec[cidx], reg, rate);
619 dev_err(bus->card->dev,
620 "error in snd_ac97_set_rate: cidx=%d, reg=0x%x, rate=%d, err=%d\n",
621 cidx, reg, rate, err);
623 reg_ok[cidx] |= (1 << (reg - AC97_PCM_FRONT_DAC_RATE));
632 snd_ac97_pcm_close(pcm);
636 EXPORT_SYMBOL(snd_ac97_pcm_open);
639 * snd_ac97_pcm_close - closes the given AC97 pcm
640 * @pcm: the ac97 pcm instance
642 * It frees the locked AC97 slots.
646 int snd_ac97_pcm_close(struct ac97_pcm *pcm)
648 struct snd_ac97_bus *bus;
649 unsigned short slots = pcm->aslots;
652 #ifdef CONFIG_SND_AC97_POWER_SAVE
653 int r = pcm->cur_dbl;
654 for (i = 3; i < 12; i++) {
655 if (!(slots & (1 << i)))
657 for (cidx = 0; cidx < 4; cidx++) {
658 if (pcm->r[r].rslots[cidx] & (1 << i)) {
659 int reg = get_slot_reg(pcm, cidx, i, r);
660 snd_ac97_update_power(pcm->r[r].codec[cidx],
668 spin_lock_irq(&pcm->bus->bus_lock);
669 for (i = 3; i < 12; i++) {
670 if (!(slots & (1 << i)))
672 for (cidx = 0; cidx < 4; cidx++)
673 bus->used_slots[pcm->stream][cidx] &= ~(1 << i);
677 spin_unlock_irq(&pcm->bus->bus_lock);
681 EXPORT_SYMBOL(snd_ac97_pcm_close);
683 static int double_rate_hw_constraint_rate(struct snd_pcm_hw_params *params,
684 struct snd_pcm_hw_rule *rule)
686 struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
687 if (channels->min > 2) {
688 static const struct snd_interval single_rates = {
692 struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
693 return snd_interval_refine(rate, &single_rates);
698 static int double_rate_hw_constraint_channels(struct snd_pcm_hw_params *params,
699 struct snd_pcm_hw_rule *rule)
701 struct snd_interval *rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
702 if (rate->min > 48000) {
703 static const struct snd_interval double_rate_channels = {
707 struct snd_interval *channels = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
708 return snd_interval_refine(channels, &double_rate_channels);
714 * snd_ac97_pcm_double_rate_rules - set double rate constraints
715 * @runtime: the runtime of the ac97 front playback pcm
717 * Installs the hardware constraint rules to prevent using double rates and
718 * more than two channels at the same time.
720 * Return: Zero if successful, or a negative error code on failure.
722 int snd_ac97_pcm_double_rate_rules(struct snd_pcm_runtime *runtime)
726 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
727 double_rate_hw_constraint_rate, NULL,
728 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
731 err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
732 double_rate_hw_constraint_channels, NULL,
733 SNDRV_PCM_HW_PARAM_RATE, -1);
737 EXPORT_SYMBOL(snd_ac97_pcm_double_rate_rules);