sound/firewire/oxfw/oxfw-pcm.c - kernel/msm-4.19 - Gitiles

 /*
  * oxfw_pcm.c - a part of driver for OXFW970/971 based devices
  *
  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
  * Licensed under the terms of the GNU General Public License, version 2.
  */

 #include "oxfw.h"

 static int hw_rule_rate(struct snd_pcm_hw_params *params,
 			struct snd_pcm_hw_rule *rule)
 {
 	u8 **formats = 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
 	};
 	struct snd_oxfw_stream_formation formation;
 	unsigned int i, err;

 	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
 		if (formats[i] == NULL)
 			continue;

 		err = snd_oxfw_stream_parse_format(formats[i], &formation);
 		if (err < 0)
 			continue;
 		if (!snd_interval_test(c, formation.pcm))
 			continue;

 		t.min = min(t.min, formation.rate);
 		t.max = max(t.max, formation.rate);

 	}
 	return snd_interval_refine(r, &t);
 }

 static int hw_rule_channels(struct snd_pcm_hw_params *params,
 			    struct snd_pcm_hw_rule *rule)
 {
 	u8 **formats = 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_oxfw_stream_formation formation;
 	unsigned int i, j, err;
 	unsigned int count, list[SND_OXFW_STREAM_FORMAT_ENTRIES] = {0};

 	count = 0;
 	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
 		if (formats[i] == NULL)
 			break;

 		err = snd_oxfw_stream_parse_format(formats[i], &formation);
 		if (err < 0)
 			continue;
 		if (!snd_interval_test(r, formation.rate))
 			continue;
 		if (list[count] == formation.pcm)
 			continue;

 		for (j = 0; j < ARRAY_SIZE(list); j++) {
 			if (list[j] == formation.pcm)
 				break;
 		}
 		if (j == ARRAY_SIZE(list)) {
 			list[count] = formation.pcm;
 			if (++count == ARRAY_SIZE(list))
 				break;
 		}
 	}

 	return snd_interval_list(c, count, list, 0);
 }

 static void limit_channels_and_rates(struct snd_pcm_hardware *hw, u8 **formats)
 {
 	struct snd_oxfw_stream_formation formation;
 	unsigned int i, err;

 	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_OXFW_STREAM_FORMAT_ENTRIES; i++) {
 		if (formats[i] == NULL)
 			break;

 		err = snd_oxfw_stream_parse_format(formats[i], &formation);
 		if (err < 0)
 			continue;

 		hw->channels_min = min(hw->channels_min, formation.pcm);
 		hw->channels_max = max(hw->channels_max, formation.pcm);

 		hw->rate_min = min(hw->rate_min, formation.rate);
 		hw->rate_max = max(hw->rate_max, formation.rate);
 		hw->rates |= snd_pcm_rate_to_rate_bit(formation.rate);
 	}
 }

 static void limit_period_and_buffer(struct snd_pcm_hardware *hw)
 {
 	hw->periods_min = 2;		/* SNDRV_PCM_INFO_BATCH */
 	hw->periods_max = UINT_MAX;

 	hw->period_bytes_min = 4 * hw->channels_max;	/* bytes for a frame */

 	/* Just to prevent from allocating much pages. */
 	hw->period_bytes_max = hw->period_bytes_min * 2048;
 	hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
 }

 static int init_hw_params(struct snd_oxfw *oxfw,
 			  struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	u8 **formats;
 	struct amdtp_stream *stream;
 	int err;

 	runtime->hw.info = SNDRV_PCM_INFO_BATCH |
 			   SNDRV_PCM_INFO_BLOCK_TRANSFER |
 			   SNDRV_PCM_INFO_INTERLEAVED |
 			   SNDRV_PCM_INFO_JOINT_DUPLEX |
 			   SNDRV_PCM_INFO_MMAP |
 			   SNDRV_PCM_INFO_MMAP_VALID;

 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 		runtime->hw.formats = AMDTP_IN_PCM_FORMAT_BITS;
 		stream = &oxfw->tx_stream;
 		formats = oxfw->tx_stream_formats;
 	} else {
 		runtime->hw.formats = AMDTP_OUT_PCM_FORMAT_BITS;
 		stream = &oxfw->rx_stream;
 		formats = oxfw->rx_stream_formats;
 	}

 	limit_channels_and_rates(&runtime->hw, formats);
 	limit_period_and_buffer(&runtime->hw);

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

 	err = amdtp_stream_add_pcm_hw_constraints(stream, runtime);
 end:
 	return err;
 }

 static int limit_to_current_params(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	struct snd_oxfw_stream_formation formation;
 	enum avc_general_plug_dir dir;
 	int err;

 	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 		dir = AVC_GENERAL_PLUG_DIR_OUT;
 	else
 		dir = AVC_GENERAL_PLUG_DIR_IN;

 	err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
 	if (err < 0)
 		goto end;

 	substream->runtime->hw.channels_min = formation.pcm;
 	substream->runtime->hw.channels_max = formation.pcm;
 	substream->runtime->hw.rate_min = formation.rate;
 	substream->runtime->hw.rate_max = formation.rate;
 end:
 	return err;
 }

 static int pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	int err;

 	err = init_hw_params(oxfw, substream);
 	if (err < 0)
 		goto end;

 	/*
 	 * When any PCM streams are already running, the available sampling
 	 * rate is limited at current value.
 	 */
 	if (amdtp_stream_pcm_running(&oxfw->tx_stream) ||
 	    amdtp_stream_pcm_running(&oxfw->rx_stream)) {
 		err = limit_to_current_params(substream);
 		if (err < 0)
 			goto end;
 	}

 	snd_pcm_set_sync(substream);
 end:
 	return err;
 }

 static int pcm_close(struct snd_pcm_substream *substream)
 {
 	return 0;
 }

 static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_oxfw *oxfw = substream->private_data;


 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 		mutex_lock(&oxfw->mutex);
 		oxfw->capture_substreams++;
 		mutex_unlock(&oxfw->mutex);
 	}

 	amdtp_stream_set_pcm_format(&oxfw->tx_stream, params_format(hw_params));

 	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 						params_buffer_bytes(hw_params));
 }
 static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
 				  struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_oxfw *oxfw = substream->private_data;

 	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 		mutex_lock(&oxfw->mutex);
 		oxfw->playback_substreams++;
 		mutex_unlock(&oxfw->mutex);
 	}

 	amdtp_stream_set_pcm_format(&oxfw->rx_stream, params_format(hw_params));

 	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 						params_buffer_bytes(hw_params));
 }

 static int pcm_capture_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;

 	mutex_lock(&oxfw->mutex);

 	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
 		oxfw->capture_substreams--;

 	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->tx_stream);

 	mutex_unlock(&oxfw->mutex);

 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }
 static int pcm_playback_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;

 	mutex_lock(&oxfw->mutex);

 	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
 		oxfw->playback_substreams--;

 	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->rx_stream);

 	mutex_unlock(&oxfw->mutex);

 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }

 static int pcm_capture_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;

 	mutex_lock(&oxfw->mutex);
 	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->tx_stream,
 					    runtime->rate, runtime->channels);
 	mutex_unlock(&oxfw->mutex);
 	if (err < 0)
 		goto end;

 	amdtp_stream_pcm_prepare(&oxfw->tx_stream);
 end:
 	return err;
 }
 static int pcm_playback_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;

 	mutex_lock(&oxfw->mutex);
 	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->rx_stream,
 					    runtime->rate, runtime->channels);
 	mutex_unlock(&oxfw->mutex);
 	if (err < 0)
 		goto end;

 	amdtp_stream_pcm_prepare(&oxfw->rx_stream);
 end:
 	return err;
 }

 static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	struct snd_pcm_substream *pcm;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		pcm = substream;
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		pcm = NULL;
 		break;
 	default:
 		return -EINVAL;
 	}
 	amdtp_stream_pcm_trigger(&oxfw->tx_stream, pcm);
 	return 0;
 }
 static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
 	struct snd_pcm_substream *pcm;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		pcm = substream;
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		pcm = NULL;
 		break;
 	default:
 		return -EINVAL;
 	}
 	amdtp_stream_pcm_trigger(&oxfw->rx_stream, pcm);
 	return 0;
 }

 static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstm)
 {
 	struct snd_oxfw *oxfw = sbstm->private_data;

 	return amdtp_stream_pcm_pointer(&oxfw->tx_stream);
 }
 static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstm)
 {
 	struct snd_oxfw *oxfw = sbstm->private_data;

 	return amdtp_stream_pcm_pointer(&oxfw->rx_stream);
 }

 int snd_oxfw_create_pcm(struct snd_oxfw *oxfw)
 {
 	static struct snd_pcm_ops capture_ops = {
 		.open      = pcm_open,
 		.close     = pcm_close,
 		.ioctl     = snd_pcm_lib_ioctl,
 		.hw_params = pcm_capture_hw_params,
 		.hw_free   = pcm_capture_hw_free,
 		.prepare   = pcm_capture_prepare,
 		.trigger   = pcm_capture_trigger,
 		.pointer   = pcm_capture_pointer,
 		.page      = snd_pcm_lib_get_vmalloc_page,
 		.mmap      = snd_pcm_lib_mmap_vmalloc,
 	};
 	static struct snd_pcm_ops playback_ops = {
 		.open      = pcm_open,
 		.close     = pcm_close,
 		.ioctl     = snd_pcm_lib_ioctl,
 		.hw_params = pcm_playback_hw_params,
 		.hw_free   = pcm_playback_hw_free,
 		.prepare   = pcm_playback_prepare,
 		.trigger   = pcm_playback_trigger,
 		.pointer   = pcm_playback_pointer,
 		.page      = snd_pcm_lib_get_vmalloc_page,
 		.mmap      = snd_pcm_lib_mmap_vmalloc,
 	};
 	struct snd_pcm *pcm;
 	unsigned int cap = 0;
 	int err;

 	if (oxfw->has_output)
 		cap = 1;

 	err = snd_pcm_new(oxfw->card, oxfw->card->driver, 0, 1, cap, &pcm);
 	if (err < 0)
 		return err;

 	pcm->private_data = oxfw;
 	strcpy(pcm->name, oxfw->card->shortname);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);
 	if (cap > 0)
 		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_ops);

 	return 0;
 }
	/*
	* oxfw_pcm.c - a part of driver for OXFW970/971 based devices
	*
	* Copyright (c) Clemens Ladisch <clemens@ladisch.de>
	* Licensed under the terms of the GNU General Public License, version 2.
	*/

	#include "oxfw.h"

	static int hw_rule_rate(struct snd_pcm_hw_params *params,
	struct snd_pcm_hw_rule *rule)
	{
	u8 **formats = 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
	};
	struct snd_oxfw_stream_formation formation;
	unsigned int i, err;

	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
	if (formats[i] == NULL)
	continue;

	err = snd_oxfw_stream_parse_format(formats[i], &formation);
	if (err < 0)
	continue;
	if (!snd_interval_test(c, formation.pcm))
	continue;

	t.min = min(t.min, formation.rate);
	t.max = max(t.max, formation.rate);

	}
	return snd_interval_refine(r, &t);
	}

	static int hw_rule_channels(struct snd_pcm_hw_params *params,
	struct snd_pcm_hw_rule *rule)
	{
	u8 **formats = 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_oxfw_stream_formation formation;
	unsigned int i, j, err;
	unsigned int count, list[SND_OXFW_STREAM_FORMAT_ENTRIES] = {0};

	count = 0;
	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
	if (formats[i] == NULL)
	break;

	err = snd_oxfw_stream_parse_format(formats[i], &formation);
	if (err < 0)
	continue;
	if (!snd_interval_test(r, formation.rate))
	continue;
	if (list[count] == formation.pcm)
	continue;

	for (j = 0; j < ARRAY_SIZE(list); j++) {
	if (list[j] == formation.pcm)
	break;
	}
	if (j == ARRAY_SIZE(list)) {
	list[count] = formation.pcm;
	if (++count == ARRAY_SIZE(list))
	break;
	}
	}

	return snd_interval_list(c, count, list, 0);
	}

	static void limit_channels_and_rates(struct snd_pcm_hardware hw, u8 *formats)
	{
	struct snd_oxfw_stream_formation formation;
	unsigned int i, err;

	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_OXFW_STREAM_FORMAT_ENTRIES; i++) {
	if (formats[i] == NULL)
	break;

	err = snd_oxfw_stream_parse_format(formats[i], &formation);
	if (err < 0)
	continue;

	hw->channels_min = min(hw->channels_min, formation.pcm);
	hw->channels_max = max(hw->channels_max, formation.pcm);

	hw->rate_min = min(hw->rate_min, formation.rate);
	hw->rate_max = max(hw->rate_max, formation.rate);
	hw->rates \|= snd_pcm_rate_to_rate_bit(formation.rate);
	}
	}

	static void limit_period_and_buffer(struct snd_pcm_hardware *hw)
	{
	hw->periods_min = 2; /* SNDRV_PCM_INFO_BATCH */
	hw->periods_max = UINT_MAX;

	hw->period_bytes_min = 4 * hw->channels_max; /* bytes for a frame */

	/* Just to prevent from allocating much pages. */
	hw->period_bytes_max = hw->period_bytes_min * 2048;
	hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
	}

	static int init_hw_params(struct snd_oxfw *oxfw,
	struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	u8 **formats;
	struct amdtp_stream *stream;
	int err;

	runtime->hw.info = SNDRV_PCM_INFO_BATCH \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \|
	SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_JOINT_DUPLEX \|
	SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID;

	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
	runtime->hw.formats = AMDTP_IN_PCM_FORMAT_BITS;
	stream = &oxfw->tx_stream;
	formats = oxfw->tx_stream_formats;
	} else {
	runtime->hw.formats = AMDTP_OUT_PCM_FORMAT_BITS;
	stream = &oxfw->rx_stream;
	formats = oxfw->rx_stream_formats;
	}

	limit_channels_and_rates(&runtime->hw, formats);
	limit_period_and_buffer(&runtime->hw);

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

	err = amdtp_stream_add_pcm_hw_constraints(stream, runtime);
	end:
	return err;
	}

	static int limit_to_current_params(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	struct snd_oxfw_stream_formation formation;
	enum avc_general_plug_dir dir;
	int err;

	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
	dir = AVC_GENERAL_PLUG_DIR_OUT;
	else
	dir = AVC_GENERAL_PLUG_DIR_IN;

	err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
	if (err < 0)
	goto end;

	substream->runtime->hw.channels_min = formation.pcm;
	substream->runtime->hw.channels_max = formation.pcm;
	substream->runtime->hw.rate_min = formation.rate;
	substream->runtime->hw.rate_max = formation.rate;
	end:
	return err;
	}

	static int pcm_open(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	int err;

	err = init_hw_params(oxfw, substream);
	if (err < 0)
	goto end;

	/*
	* When any PCM streams are already running, the available sampling
	* rate is limited at current value.
	*/
	if (amdtp_stream_pcm_running(&oxfw->tx_stream) \|\|
	amdtp_stream_pcm_running(&oxfw->rx_stream)) {
	err = limit_to_current_params(substream);
	if (err < 0)
	goto end;
	}

	snd_pcm_set_sync(substream);
	end:
	return err;
	}

	static int pcm_close(struct snd_pcm_substream *substream)
	{
	return 0;
	}

	static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params)
	{
	struct snd_oxfw *oxfw = substream->private_data;


	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
	mutex_lock(&oxfw->mutex);
	oxfw->capture_substreams++;
	mutex_unlock(&oxfw->mutex);
	}

	amdtp_stream_set_pcm_format(&oxfw->tx_stream, params_format(hw_params));

	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
	params_buffer_bytes(hw_params));
	}
	static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params)
	{
	struct snd_oxfw *oxfw = substream->private_data;

	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
	mutex_lock(&oxfw->mutex);
	oxfw->playback_substreams++;
	mutex_unlock(&oxfw->mutex);
	}

	amdtp_stream_set_pcm_format(&oxfw->rx_stream, params_format(hw_params));

	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
	params_buffer_bytes(hw_params));
	}

	static int pcm_capture_hw_free(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;

	mutex_lock(&oxfw->mutex);

	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
	oxfw->capture_substreams--;

	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->tx_stream);

	mutex_unlock(&oxfw->mutex);

	return snd_pcm_lib_free_vmalloc_buffer(substream);
	}
	static int pcm_playback_hw_free(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;

	mutex_lock(&oxfw->mutex);

	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
	oxfw->playback_substreams--;

	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->rx_stream);

	mutex_unlock(&oxfw->mutex);

	return snd_pcm_lib_free_vmalloc_buffer(substream);
	}

	static int pcm_capture_prepare(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;

	mutex_lock(&oxfw->mutex);
	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->tx_stream,
	runtime->rate, runtime->channels);
	mutex_unlock(&oxfw->mutex);
	if (err < 0)
	goto end;

	amdtp_stream_pcm_prepare(&oxfw->tx_stream);
	end:
	return err;
	}
	static int pcm_playback_prepare(struct snd_pcm_substream *substream)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;

	mutex_lock(&oxfw->mutex);
	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->rx_stream,
	runtime->rate, runtime->channels);
	mutex_unlock(&oxfw->mutex);
	if (err < 0)
	goto end;

	amdtp_stream_pcm_prepare(&oxfw->rx_stream);
	end:
	return err;
	}

	static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	struct snd_pcm_substream *pcm;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	pcm = substream;
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	pcm = NULL;
	break;
	default:
	return -EINVAL;
	}
	amdtp_stream_pcm_trigger(&oxfw->tx_stream, pcm);
	return 0;
	}
	static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_oxfw *oxfw = substream->private_data;
	struct snd_pcm_substream *pcm;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	pcm = substream;
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	pcm = NULL;
	break;
	default:
	return -EINVAL;
	}
	amdtp_stream_pcm_trigger(&oxfw->rx_stream, pcm);
	return 0;
	}

	static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstm)
	{
	struct snd_oxfw *oxfw = sbstm->private_data;

	return amdtp_stream_pcm_pointer(&oxfw->tx_stream);
	}
	static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstm)
	{
	struct snd_oxfw *oxfw = sbstm->private_data;

	return amdtp_stream_pcm_pointer(&oxfw->rx_stream);
	}

	int snd_oxfw_create_pcm(struct snd_oxfw *oxfw)
	{
	static struct snd_pcm_ops capture_ops = {
	.open = pcm_open,
	.close = pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = pcm_capture_hw_params,
	.hw_free = pcm_capture_hw_free,
	.prepare = pcm_capture_prepare,
	.trigger = pcm_capture_trigger,
	.pointer = pcm_capture_pointer,
	.page = snd_pcm_lib_get_vmalloc_page,
	.mmap = snd_pcm_lib_mmap_vmalloc,
	};
	static struct snd_pcm_ops playback_ops = {
	.open = pcm_open,
	.close = pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = pcm_playback_hw_params,
	.hw_free = pcm_playback_hw_free,
	.prepare = pcm_playback_prepare,
	.trigger = pcm_playback_trigger,
	.pointer = pcm_playback_pointer,
	.page = snd_pcm_lib_get_vmalloc_page,
	.mmap = snd_pcm_lib_mmap_vmalloc,
	};
	struct snd_pcm *pcm;
	unsigned int cap = 0;
	int err;

	if (oxfw->has_output)
	cap = 1;

	err = snd_pcm_new(oxfw->card, oxfw->card->driver, 0, 1, cap, &pcm);
	if (err < 0)
	return err;

	pcm->private_data = oxfw;
	strcpy(pcm->name, oxfw->card->shortname);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);
	if (cap > 0)
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_ops);

	return 0;
	}