sound/firewire/bebob/bebob_pcm.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * bebob_pcm.c - a part of driver for BeBoB based devices
  *
  * Copyright (c) 2013-2014 Takashi Sakamoto
  */

 #include "./bebob.h"

 static int
 hw_rule_rate(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
 {
 	struct snd_bebob_stream_formation *formations = rule->private;
 	struct snd_interval *r =
 		hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
 	const struct snd_interval *c =
 		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 	struct snd_interval t = {
 		.min = UINT_MAX, .max = 0, .integer = 1
 	};
 	unsigned int i;

 	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
 		/* entry is invalid */
 		if (formations[i].pcm == 0)
 			continue;

 		if (!snd_interval_test(c, formations[i].pcm))
 			continue;

 		t.min = min(t.min, snd_bebob_rate_table[i]);
 		t.max = max(t.max, snd_bebob_rate_table[i]);

 	}
 	return snd_interval_refine(r, &t);
 }

 static int
 hw_rule_channels(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
 {
 	struct snd_bebob_stream_formation *formations = rule->private;
 	struct snd_interval *c =
 		hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
 	const struct snd_interval *r =
 		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
 	struct snd_interval t = {
 		.min = UINT_MAX, .max = 0, .integer = 1
 	};

 	unsigned int i;

 	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
 		/* entry is invalid */
 		if (formations[i].pcm == 0)
 			continue;

 		if (!snd_interval_test(r, snd_bebob_rate_table[i]))
 			continue;

 		t.min = min(t.min, formations[i].pcm);
 		t.max = max(t.max, formations[i].pcm);
 	}

 	return snd_interval_refine(c, &t);
 }

 static void
 limit_channels_and_rates(struct snd_pcm_hardware *hw,
 			 struct snd_bebob_stream_formation *formations)
 {
 	unsigned int i;

 	hw->channels_min = UINT_MAX;
 	hw->channels_max = 0;

 	hw->rate_min = UINT_MAX;
 	hw->rate_max = 0;
 	hw->rates = 0;

 	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
 		/* entry has no PCM channels */
 		if (formations[i].pcm == 0)
 			continue;

 		hw->channels_min = min(hw->channels_min, formations[i].pcm);
 		hw->channels_max = max(hw->channels_max, formations[i].pcm);

 		hw->rate_min = min(hw->rate_min, snd_bebob_rate_table[i]);
 		hw->rate_max = max(hw->rate_max, snd_bebob_rate_table[i]);
 		hw->rates |= snd_pcm_rate_to_rate_bit(snd_bebob_rate_table[i]);
 	}
 }

 static int
 pcm_init_hw_params(struct snd_bebob *bebob,
 		   struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct amdtp_stream *s;
 	struct snd_bebob_stream_formation *formations;
 	int err;

 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 		runtime->hw.formats = AM824_IN_PCM_FORMAT_BITS;
 		s = &bebob->tx_stream;
 		formations = bebob->tx_stream_formations;
 	} else {
 		runtime->hw.formats = AM824_OUT_PCM_FORMAT_BITS;
 		s = &bebob->rx_stream;
 		formations = bebob->rx_stream_formations;
 	}

 	limit_channels_and_rates(&runtime->hw, formations);

 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
 				  hw_rule_channels, formations,
 				  SNDRV_PCM_HW_PARAM_RATE, -1);
 	if (err < 0)
 		goto end;

 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
 				  hw_rule_rate, formations,
 				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 	if (err < 0)
 		goto end;

 	err = amdtp_am824_add_pcm_hw_constraints(s, runtime);
 end:
 	return err;
 }

 static int pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	const struct snd_bebob_rate_spec *spec = bebob->spec->rate;
 	struct amdtp_domain *d = &bebob->domain;
 	enum snd_bebob_clock_type src;
 	int err;

 	err = snd_bebob_stream_lock_try(bebob);
 	if (err < 0)
 		return err;

 	err = pcm_init_hw_params(bebob, substream);
 	if (err < 0)
 		goto err_locked;

 	err = snd_bebob_stream_get_clock_src(bebob, &src);
 	if (err < 0)
 		goto err_locked;

 	mutex_lock(&bebob->mutex);

 	// When source of clock is not internal or any stream is reserved for
 	// transmission of PCM frames, the available sampling rate is limited
 	// at current one.
 	if (src == SND_BEBOB_CLOCK_TYPE_EXTERNAL ||
 	    (bebob->substreams_counter > 0 && d->events_per_period > 0)) {
 		unsigned int frames_per_period = d->events_per_period;
 		unsigned int frames_per_buffer = d->events_per_buffer;
 		unsigned int sampling_rate;

 		err = spec->get(bebob, &sampling_rate);
 		if (err < 0) {
 			mutex_unlock(&bebob->mutex);
 			dev_err(&bebob->unit->device,
 				"fail to get sampling rate: %d\n", err);
 			goto err_locked;
 		}

 		substream->runtime->hw.rate_min = sampling_rate;
 		substream->runtime->hw.rate_max = sampling_rate;

 		if (frames_per_period > 0) {
 			err = snd_pcm_hw_constraint_minmax(substream->runtime,
 					SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
 					frames_per_period, frames_per_period);
 			if (err < 0) {
 				mutex_unlock(&bebob->mutex);
 				goto err_locked;
 			}

 			err = snd_pcm_hw_constraint_minmax(substream->runtime,
 					SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
 					frames_per_buffer, frames_per_buffer);
 			if (err < 0) {
 				mutex_unlock(&bebob->mutex);
 				goto err_locked;
 			}
 		}
 	}

 	mutex_unlock(&bebob->mutex);

 	snd_pcm_set_sync(substream);

 	return 0;
 err_locked:
 	snd_bebob_stream_lock_release(bebob);
 	return err;
 }

 static int
 pcm_close(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	snd_bebob_stream_lock_release(bebob);
 	return 0;
 }

 static int pcm_hw_params(struct snd_pcm_substream *substream,
 			 struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	int err = 0;

 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 		unsigned int rate = params_rate(hw_params);
 		unsigned int frames_per_period = params_period_size(hw_params);
 		unsigned int frames_per_buffer = params_buffer_size(hw_params);

 		mutex_lock(&bebob->mutex);
 		err = snd_bebob_stream_reserve_duplex(bebob, rate,
 					frames_per_period, frames_per_buffer);
 		if (err >= 0)
 			++bebob->substreams_counter;
 		mutex_unlock(&bebob->mutex);
 	}

 	return err;
 }

 static int pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;

 	mutex_lock(&bebob->mutex);

 	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
 		bebob->substreams_counter--;

 	snd_bebob_stream_stop_duplex(bebob);

 	mutex_unlock(&bebob->mutex);

 	return 0;
 }

 static int
 pcm_capture_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	int err;

 	err = snd_bebob_stream_start_duplex(bebob);
 	if (err >= 0)
 		amdtp_stream_pcm_prepare(&bebob->tx_stream);

 	return err;
 }
 static int
 pcm_playback_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 	int err;

 	err = snd_bebob_stream_start_duplex(bebob);
 	if (err >= 0)
 		amdtp_stream_pcm_prepare(&bebob->rx_stream);

 	return err;
 }

 static int
 pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_bebob *bebob = substream->private_data;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		amdtp_stream_pcm_trigger(&bebob->tx_stream, substream);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		amdtp_stream_pcm_trigger(&bebob->tx_stream, NULL);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }
 static int
 pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_bebob *bebob = substream->private_data;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		amdtp_stream_pcm_trigger(&bebob->rx_stream, substream);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		amdtp_stream_pcm_trigger(&bebob->rx_stream, NULL);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
 {
 	struct snd_bebob *bebob = sbstrm->private_data;

 	return amdtp_domain_stream_pcm_pointer(&bebob->domain,
 					       &bebob->tx_stream);
 }
 static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
 {
 	struct snd_bebob *bebob = sbstrm->private_data;

 	return amdtp_domain_stream_pcm_pointer(&bebob->domain,
 					       &bebob->rx_stream);
 }

 static int pcm_capture_ack(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;

 	return amdtp_domain_stream_pcm_ack(&bebob->domain, &bebob->tx_stream);
 }

 static int pcm_playback_ack(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;

 	return amdtp_domain_stream_pcm_ack(&bebob->domain, &bebob->rx_stream);
 }

 int snd_bebob_create_pcm_devices(struct snd_bebob *bebob)
 {
 	static const struct snd_pcm_ops capture_ops = {
 		.open		= pcm_open,
 		.close		= pcm_close,
 		.hw_params	= pcm_hw_params,
 		.hw_free	= pcm_hw_free,
 		.prepare	= pcm_capture_prepare,
 		.trigger	= pcm_capture_trigger,
 		.pointer	= pcm_capture_pointer,
 		.ack		= pcm_capture_ack,
 	};
 	static const struct snd_pcm_ops playback_ops = {
 		.open		= pcm_open,
 		.close		= pcm_close,
 		.hw_params	= pcm_hw_params,
 		.hw_free	= pcm_hw_free,
 		.prepare	= pcm_playback_prepare,
 		.trigger	= pcm_playback_trigger,
 		.pointer	= pcm_playback_pointer,
 		.ack		= pcm_playback_ack,
 	};
 	struct snd_pcm *pcm;
 	int err;

 	err = snd_pcm_new(bebob->card, bebob->card->driver, 0, 1, 1, &pcm);
 	if (err < 0)
 		goto end;

 	pcm->private_data = bebob;
 	snprintf(pcm->name, sizeof(pcm->name),
 		 "%s PCM", bebob->card->shortname);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_ops);
 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
 end:
 	return err;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* bebob_pcm.c - a part of driver for BeBoB based devices
	*
	* Copyright (c) 2013-2014 Takashi Sakamoto
	*/

	#include "./bebob.h"

	static int
	hw_rule_rate(struct snd_pcm_hw_params params, struct snd_pcm_hw_rule rule)
	{
	struct snd_bebob_stream_formation *formations = rule->private;
	struct snd_interval *r =
	hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	const struct snd_interval *c =
	hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	struct snd_interval t = {
	.min = UINT_MAX, .max = 0, .integer = 1
	};
	unsigned int i;

	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
	/* entry is invalid */
	if (formations[i].pcm == 0)
	continue;

	if (!snd_interval_test(c, formations[i].pcm))
	continue;

	t.min = min(t.min, snd_bebob_rate_table[i]);
	t.max = max(t.max, snd_bebob_rate_table[i]);

	}
	return snd_interval_refine(r, &t);
	}

	static int
	hw_rule_channels(struct snd_pcm_hw_params params, struct snd_pcm_hw_rule rule)
	{
	struct snd_bebob_stream_formation *formations = rule->private;
	struct snd_interval *c =
	hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	const struct snd_interval *r =
	hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
	struct snd_interval t = {
	.min = UINT_MAX, .max = 0, .integer = 1
	};

	unsigned int i;

	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
	/* entry is invalid */
	if (formations[i].pcm == 0)
	continue;

	if (!snd_interval_test(r, snd_bebob_rate_table[i]))
	continue;

	t.min = min(t.min, formations[i].pcm);
	t.max = max(t.max, formations[i].pcm);
	}

	return snd_interval_refine(c, &t);
	}

	static void
	limit_channels_and_rates(struct snd_pcm_hardware *hw,
	struct snd_bebob_stream_formation *formations)
	{
	unsigned int i;

	hw->channels_min = UINT_MAX;
	hw->channels_max = 0;

	hw->rate_min = UINT_MAX;
	hw->rate_max = 0;
	hw->rates = 0;

	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
	/* entry has no PCM channels */
	if (formations[i].pcm == 0)
	continue;

	hw->channels_min = min(hw->channels_min, formations[i].pcm);
	hw->channels_max = max(hw->channels_max, formations[i].pcm);

	hw->rate_min = min(hw->rate_min, snd_bebob_rate_table[i]);
	hw->rate_max = max(hw->rate_max, snd_bebob_rate_table[i]);
	hw->rates \|= snd_pcm_rate_to_rate_bit(snd_bebob_rate_table[i]);
	}
	}

	static int
	pcm_init_hw_params(struct snd_bebob *bebob,
	struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct amdtp_stream *s;
	struct snd_bebob_stream_formation *formations;
	int err;

	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
	runtime->hw.formats = AM824_IN_PCM_FORMAT_BITS;
	s = &bebob->tx_stream;
	formations = bebob->tx_stream_formations;
	} else {
	runtime->hw.formats = AM824_OUT_PCM_FORMAT_BITS;
	s = &bebob->rx_stream;
	formations = bebob->rx_stream_formations;
	}

	limit_channels_and_rates(&runtime->hw, formations);

	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
	hw_rule_channels, formations,
	SNDRV_PCM_HW_PARAM_RATE, -1);
	if (err < 0)
	goto end;

	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
	hw_rule_rate, formations,
	SNDRV_PCM_HW_PARAM_CHANNELS, -1);
	if (err < 0)
	goto end;

	err = amdtp_am824_add_pcm_hw_constraints(s, runtime);
	end:
	return err;
	}

	static int pcm_open(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;
	const struct snd_bebob_rate_spec *spec = bebob->spec->rate;
	struct amdtp_domain *d = &bebob->domain;
	enum snd_bebob_clock_type src;
	int err;

	err = snd_bebob_stream_lock_try(bebob);
	if (err < 0)
	return err;

	err = pcm_init_hw_params(bebob, substream);
	if (err < 0)
	goto err_locked;

	err = snd_bebob_stream_get_clock_src(bebob, &src);
	if (err < 0)
	goto err_locked;

	mutex_lock(&bebob->mutex);

	// When source of clock is not internal or any stream is reserved for
	// transmission of PCM frames, the available sampling rate is limited
	// at current one.
	if (src == SND_BEBOB_CLOCK_TYPE_EXTERNAL \|\|
	(bebob->substreams_counter > 0 && d->events_per_period > 0)) {
	unsigned int frames_per_period = d->events_per_period;
	unsigned int frames_per_buffer = d->events_per_buffer;
	unsigned int sampling_rate;

	err = spec->get(bebob, &sampling_rate);
	if (err < 0) {
	mutex_unlock(&bebob->mutex);
	dev_err(&bebob->unit->device,
	"fail to get sampling rate: %d\n", err);
	goto err_locked;
	}

	substream->runtime->hw.rate_min = sampling_rate;
	substream->runtime->hw.rate_max = sampling_rate;

	if (frames_per_period > 0) {
	err = snd_pcm_hw_constraint_minmax(substream->runtime,
	SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
	frames_per_period, frames_per_period);
	if (err < 0) {
	mutex_unlock(&bebob->mutex);
	goto err_locked;
	}

	err = snd_pcm_hw_constraint_minmax(substream->runtime,
	SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
	frames_per_buffer, frames_per_buffer);
	if (err < 0) {
	mutex_unlock(&bebob->mutex);
	goto err_locked;
	}
	}
	}

	mutex_unlock(&bebob->mutex);

	snd_pcm_set_sync(substream);

	return 0;
	err_locked:
	snd_bebob_stream_lock_release(bebob);
	return err;
	}

	static int
	pcm_close(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;
	snd_bebob_stream_lock_release(bebob);
	return 0;
	}

	static int pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params)
	{
	struct snd_bebob *bebob = substream->private_data;
	int err = 0;

	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
	unsigned int rate = params_rate(hw_params);
	unsigned int frames_per_period = params_period_size(hw_params);
	unsigned int frames_per_buffer = params_buffer_size(hw_params);

	mutex_lock(&bebob->mutex);
	err = snd_bebob_stream_reserve_duplex(bebob, rate,
	frames_per_period, frames_per_buffer);
	if (err >= 0)
	++bebob->substreams_counter;
	mutex_unlock(&bebob->mutex);
	}

	return err;
	}

	static int pcm_hw_free(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;

	mutex_lock(&bebob->mutex);

	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
	bebob->substreams_counter--;

	snd_bebob_stream_stop_duplex(bebob);

	mutex_unlock(&bebob->mutex);

	return 0;
	}

	static int
	pcm_capture_prepare(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;
	int err;

	err = snd_bebob_stream_start_duplex(bebob);
	if (err >= 0)
	amdtp_stream_pcm_prepare(&bebob->tx_stream);

	return err;
	}
	static int
	pcm_playback_prepare(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;
	int err;

	err = snd_bebob_stream_start_duplex(bebob);
	if (err >= 0)
	amdtp_stream_pcm_prepare(&bebob->rx_stream);

	return err;
	}

	static int
	pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_bebob *bebob = substream->private_data;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	amdtp_stream_pcm_trigger(&bebob->tx_stream, substream);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	amdtp_stream_pcm_trigger(&bebob->tx_stream, NULL);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}
	static int
	pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_bebob *bebob = substream->private_data;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	amdtp_stream_pcm_trigger(&bebob->rx_stream, substream);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	amdtp_stream_pcm_trigger(&bebob->rx_stream, NULL);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
	{
	struct snd_bebob *bebob = sbstrm->private_data;

	return amdtp_domain_stream_pcm_pointer(&bebob->domain,
	&bebob->tx_stream);
	}
	static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
	{
	struct snd_bebob *bebob = sbstrm->private_data;

	return amdtp_domain_stream_pcm_pointer(&bebob->domain,
	&bebob->rx_stream);
	}

	static int pcm_capture_ack(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;

	return amdtp_domain_stream_pcm_ack(&bebob->domain, &bebob->tx_stream);
	}

	static int pcm_playback_ack(struct snd_pcm_substream *substream)
	{
	struct snd_bebob *bebob = substream->private_data;

	return amdtp_domain_stream_pcm_ack(&bebob->domain, &bebob->rx_stream);
	}

	int snd_bebob_create_pcm_devices(struct snd_bebob *bebob)
	{
	static const struct snd_pcm_ops capture_ops = {
	.open = pcm_open,
	.close = pcm_close,
	.hw_params = pcm_hw_params,
	.hw_free = pcm_hw_free,
	.prepare = pcm_capture_prepare,
	.trigger = pcm_capture_trigger,
	.pointer = pcm_capture_pointer,
	.ack = pcm_capture_ack,
	};
	static const struct snd_pcm_ops playback_ops = {
	.open = pcm_open,
	.close = pcm_close,
	.hw_params = pcm_hw_params,
	.hw_free = pcm_hw_free,
	.prepare = pcm_playback_prepare,
	.trigger = pcm_playback_trigger,
	.pointer = pcm_playback_pointer,
	.ack = pcm_playback_ack,
	};
	struct snd_pcm *pcm;
	int err;

	err = snd_pcm_new(bebob->card, bebob->card->driver, 0, 1, 1, &pcm);
	if (err < 0)
	goto end;

	pcm->private_data = bebob;
	snprintf(pcm->name, sizeof(pcm->name),
	"%s PCM", bebob->card->shortname);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_ops);
	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
	end:
	return err;
	}