sound/firewire/tascam/tascam-stream.c - arm/linux - Git at Google

 /*
  * tascam-stream.c - a part of driver for TASCAM FireWire series
  *
  * Copyright (c) 2015 Takashi Sakamoto
  *
  * Licensed under the terms of the GNU General Public License, version 2.
  */

 #include <linux/delay.h>
 #include "tascam.h"

 #define CALLBACK_TIMEOUT 500

 static int get_clock(struct snd_tscm *tscm, u32 *data)
 {
 	__be32 reg;
 	int err;

 	err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS,
 				 &reg, sizeof(reg), 0);
 	if (err >= 0)
 		*data = be32_to_cpu(reg);

 	return err;
 }

 static int set_clock(struct snd_tscm *tscm, unsigned int rate,
 		     enum snd_tscm_clock clock)
 {
 	u32 data;
 	__be32 reg;
 	int err;

 	err = get_clock(tscm, &data);
 	if (err < 0)
 		return err;
 	data &= 0x0000ffff;

 	if (rate > 0) {
 		data &= 0x000000ff;
 		/* Base rate. */
 		if ((rate % 44100) == 0) {
 			data |= 0x00000100;
 			/* Multiplier. */
 			if (rate / 44100 == 2)
 				data |= 0x00008000;
 		} else if ((rate % 48000) == 0) {
 			data |= 0x00000200;
 			/* Multiplier. */
 			if (rate / 48000 == 2)
 				data |= 0x00008000;
 		} else {
 			return -EAGAIN;
 		}
 	}

 	if (clock != INT_MAX) {
 		data &= 0x0000ff00;
 		data |= clock + 1;
 	}

 	reg = cpu_to_be32(data);

 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	if (data & 0x00008000)
 		reg = cpu_to_be32(0x0000001a);
 	else
 		reg = cpu_to_be32(0x0000000d);

 	return snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				  TSCM_ADDR_BASE + TSCM_OFFSET_MULTIPLEX_MODE,
 				  &reg, sizeof(reg), 0);
 }

 int snd_tscm_stream_get_rate(struct snd_tscm *tscm, unsigned int *rate)
 {
 	u32 data = 0x0;
 	unsigned int trials = 0;
 	int err;

 	while (data == 0x0 || trials++ < 5) {
 		err = get_clock(tscm, &data);
 		if (err < 0)
 			return err;

 		data = (data & 0xff000000) >> 24;
 	}

 	/* Check base rate. */
 	if ((data & 0x0f) == 0x01)
 		*rate = 44100;
 	else if ((data & 0x0f) == 0x02)
 		*rate = 48000;
 	else
 		return -EAGAIN;

 	/* Check multiplier. */
 	if ((data & 0xf0) == 0x80)
 		*rate *= 2;
 	else if ((data & 0xf0) != 0x00)
 		return -EAGAIN;

 	return err;
 }

 int snd_tscm_stream_get_clock(struct snd_tscm *tscm, enum snd_tscm_clock *clock)
 {
 	u32 data;
 	int err;

 	err = get_clock(tscm, &data);
 	if (err < 0)
 		return err;

 	*clock = ((data & 0x00ff0000) >> 16) - 1;
 	if (*clock < 0 || *clock > SND_TSCM_CLOCK_ADAT)
 		return -EIO;

 	return 0;
 }

 static int enable_data_channels(struct snd_tscm *tscm)
 {
 	__be32 reg;
 	u32 data;
 	unsigned int i;
 	int err;

 	data = 0;
 	for (i = 0; i < tscm->spec->pcm_capture_analog_channels; ++i)
 		data |= BIT(i);
 	if (tscm->spec->has_adat)
 		data |= 0x0000ff00;
 	if (tscm->spec->has_spdif)
 		data |= 0x00030000;

 	reg = cpu_to_be32(data);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_TX_PCM_CHANNELS,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	data = 0;
 	for (i = 0; i < tscm->spec->pcm_playback_analog_channels; ++i)
 		data |= BIT(i);
 	if (tscm->spec->has_adat)
 		data |= 0x0000ff00;
 	if (tscm->spec->has_spdif)
 		data |= 0x00030000;

 	reg = cpu_to_be32(data);
 	return snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				  TSCM_ADDR_BASE + TSCM_OFFSET_RX_PCM_CHANNELS,
 				  &reg, sizeof(reg), 0);
 }

 static int set_stream_formats(struct snd_tscm *tscm, unsigned int rate)
 {
 	__be32 reg;
 	int err;

 	/* Set an option for unknown purpose. */
 	reg = cpu_to_be32(0x00200000);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_SET_OPTION,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	err = enable_data_channels(tscm);
 	if (err < 0)
 		return err;

 	return set_clock(tscm, rate, INT_MAX);
 }

 static void finish_session(struct snd_tscm *tscm)
 {
 	__be32 reg;

 	reg = 0;
 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 			   TSCM_ADDR_BASE + TSCM_OFFSET_START_STREAMING,
 			   &reg, sizeof(reg), 0);

 	reg = 0;
 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 			   TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_ON,
 			   &reg, sizeof(reg), 0);

 }

 static int begin_session(struct snd_tscm *tscm)
 {
 	__be32 reg;
 	int err;

 	reg = cpu_to_be32(0x00000001);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_START_STREAMING,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	reg = cpu_to_be32(0x00000001);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_ON,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	/* Set an option for unknown purpose. */
 	reg = cpu_to_be32(0x00002000);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_SET_OPTION,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		return err;

 	/* Start multiplexing PCM samples on packets. */
 	reg = cpu_to_be32(0x00000001);
 	return snd_fw_transaction(tscm->unit,
 				  TCODE_WRITE_QUADLET_REQUEST,
 				  TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_ON,
 				  &reg, sizeof(reg), 0);
 }

 static void release_resources(struct snd_tscm *tscm)
 {
 	__be32 reg;

 	/* Unregister channels. */
 	reg = cpu_to_be32(0x00000000);
 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 			   TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_CH,
 			   &reg, sizeof(reg), 0);
 	reg = cpu_to_be32(0x00000000);
 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 			   TSCM_ADDR_BASE + TSCM_OFFSET_UNKNOWN,
 			   &reg, sizeof(reg), 0);
 	reg = cpu_to_be32(0x00000000);
 	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 			   TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_CH,
 			   &reg, sizeof(reg), 0);

 	/* Release isochronous resources. */
 	fw_iso_resources_free(&tscm->tx_resources);
 	fw_iso_resources_free(&tscm->rx_resources);
 }

 static int keep_resources(struct snd_tscm *tscm, unsigned int rate)
 {
 	__be32 reg;
 	int err;

 	/* Keep resources for in-stream. */
 	err = amdtp_tscm_set_parameters(&tscm->tx_stream, rate);
 	if (err < 0)
 		return err;
 	err = fw_iso_resources_allocate(&tscm->tx_resources,
 			amdtp_stream_get_max_payload(&tscm->tx_stream),
 			fw_parent_device(tscm->unit)->max_speed);
 	if (err < 0)
 		goto error;

 	/* Keep resources for out-stream. */
 	err = amdtp_tscm_set_parameters(&tscm->rx_stream, rate);
 	if (err < 0)
 		return err;
 	err = fw_iso_resources_allocate(&tscm->rx_resources,
 			amdtp_stream_get_max_payload(&tscm->rx_stream),
 			fw_parent_device(tscm->unit)->max_speed);
 	if (err < 0)
 		return err;

 	/* Register the isochronous channel for transmitting stream. */
 	reg = cpu_to_be32(tscm->tx_resources.channel);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_CH,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		goto error;

 	/* Unknown */
 	reg = cpu_to_be32(0x00000002);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_UNKNOWN,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		goto error;

 	/* Register the isochronous channel for receiving stream. */
 	reg = cpu_to_be32(tscm->rx_resources.channel);
 	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
 				 TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_CH,
 				 &reg, sizeof(reg), 0);
 	if (err < 0)
 		goto error;

 	return 0;
 error:
 	release_resources(tscm);
 	return err;
 }

 int snd_tscm_stream_init_duplex(struct snd_tscm *tscm)
 {
 	unsigned int pcm_channels;
 	int err;

 	/* For out-stream. */
 	err = fw_iso_resources_init(&tscm->rx_resources, tscm->unit);
 	if (err < 0)
 		return err;
 	pcm_channels = tscm->spec->pcm_playback_analog_channels;
 	if (tscm->spec->has_adat)
 		pcm_channels += 8;
 	if (tscm->spec->has_spdif)
 		pcm_channels += 2;
 	err = amdtp_tscm_init(&tscm->rx_stream, tscm->unit, AMDTP_OUT_STREAM,
 			      pcm_channels);
 	if (err < 0)
 		return err;

 	/* For in-stream. */
 	err = fw_iso_resources_init(&tscm->tx_resources, tscm->unit);
 	if (err < 0)
 		return err;
 	pcm_channels = tscm->spec->pcm_capture_analog_channels;
 	if (tscm->spec->has_adat)
 		pcm_channels += 8;
 	if (tscm->spec->has_spdif)
 		pcm_channels += 2;
 	err = amdtp_tscm_init(&tscm->tx_stream, tscm->unit, AMDTP_IN_STREAM,
 			      pcm_channels);
 	if (err < 0)
 		amdtp_stream_destroy(&tscm->rx_stream);

 	return err;
 }

 /* At bus reset, streaming is stopped and some registers are clear. */
 void snd_tscm_stream_update_duplex(struct snd_tscm *tscm)
 {
 	amdtp_stream_pcm_abort(&tscm->tx_stream);
 	amdtp_stream_stop(&tscm->tx_stream);

 	amdtp_stream_pcm_abort(&tscm->rx_stream);
 	amdtp_stream_stop(&tscm->rx_stream);
 }

 /*
  * This function should be called before starting streams or after stopping
  * streams.
  */
 void snd_tscm_stream_destroy_duplex(struct snd_tscm *tscm)
 {
 	amdtp_stream_destroy(&tscm->rx_stream);
 	amdtp_stream_destroy(&tscm->tx_stream);

 	fw_iso_resources_destroy(&tscm->rx_resources);
 	fw_iso_resources_destroy(&tscm->tx_resources);
 }

 int snd_tscm_stream_start_duplex(struct snd_tscm *tscm, unsigned int rate)
 {
 	unsigned int curr_rate;
 	int err;

 	if (tscm->substreams_counter == 0)
 		return 0;

 	err = snd_tscm_stream_get_rate(tscm, &curr_rate);
 	if (err < 0)
 		return err;
 	if (curr_rate != rate ||
 	    amdtp_streaming_error(&tscm->rx_stream) ||
 	    amdtp_streaming_error(&tscm->tx_stream)) {
 		finish_session(tscm);

 		amdtp_stream_stop(&tscm->rx_stream);
 		amdtp_stream_stop(&tscm->tx_stream);

 		release_resources(tscm);
 	}

 	if (!amdtp_stream_running(&tscm->rx_stream)) {
 		err = keep_resources(tscm, rate);
 		if (err < 0)
 			goto error;

 		err = set_stream_formats(tscm, rate);
 		if (err < 0)
 			goto error;

 		err = begin_session(tscm);
 		if (err < 0)
 			goto error;

 		err = amdtp_stream_start(&tscm->rx_stream,
 				tscm->rx_resources.channel,
 				fw_parent_device(tscm->unit)->max_speed);
 		if (err < 0)
 			goto error;

 		if (!amdtp_stream_wait_callback(&tscm->rx_stream,
 						CALLBACK_TIMEOUT)) {
 			err = -ETIMEDOUT;
 			goto error;
 		}
 	}

 	if (!amdtp_stream_running(&tscm->tx_stream)) {
 		err = amdtp_stream_start(&tscm->tx_stream,
 				tscm->tx_resources.channel,
 				fw_parent_device(tscm->unit)->max_speed);
 		if (err < 0)
 			goto error;

 		if (!amdtp_stream_wait_callback(&tscm->tx_stream,
 						CALLBACK_TIMEOUT)) {
 			err = -ETIMEDOUT;
 			goto error;
 		}
 	}

 	return 0;
 error:
 	amdtp_stream_stop(&tscm->rx_stream);
 	amdtp_stream_stop(&tscm->tx_stream);

 	finish_session(tscm);
 	release_resources(tscm);

 	return err;
 }

 void snd_tscm_stream_stop_duplex(struct snd_tscm *tscm)
 {
 	if (tscm->substreams_counter > 0)
 		return;

 	amdtp_stream_stop(&tscm->tx_stream);
 	amdtp_stream_stop(&tscm->rx_stream);

 	finish_session(tscm);
 	release_resources(tscm);
 }

 void snd_tscm_stream_lock_changed(struct snd_tscm *tscm)
 {
 	tscm->dev_lock_changed = true;
 	wake_up(&tscm->hwdep_wait);
 }

 int snd_tscm_stream_lock_try(struct snd_tscm *tscm)
 {
 	int err;

 	spin_lock_irq(&tscm->lock);

 	/* user land lock this */
 	if (tscm->dev_lock_count < 0) {
 		err = -EBUSY;
 		goto end;
 	}

 	/* this is the first time */
 	if (tscm->dev_lock_count++ == 0)
 		snd_tscm_stream_lock_changed(tscm);
 	err = 0;
 end:
 	spin_unlock_irq(&tscm->lock);
 	return err;
 }

 void snd_tscm_stream_lock_release(struct snd_tscm *tscm)
 {
 	spin_lock_irq(&tscm->lock);

 	if (WARN_ON(tscm->dev_lock_count <= 0))
 		goto end;
 	if (--tscm->dev_lock_count == 0)
 		snd_tscm_stream_lock_changed(tscm);
 end:
 	spin_unlock_irq(&tscm->lock);
 }
	/*
	* tascam-stream.c - a part of driver for TASCAM FireWire series
	*
	* Copyright (c) 2015 Takashi Sakamoto
	*
	* Licensed under the terms of the GNU General Public License, version 2.
	*/

	#include <linux/delay.h>
	#include "tascam.h"

	#define CALLBACK_TIMEOUT 500

	static int get_clock(struct snd_tscm tscm, u32 data)
	{
	__be32 reg;
	int err;

	err = snd_fw_transaction(tscm->unit, TCODE_READ_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS,
	&reg, sizeof(reg), 0);
	if (err >= 0)
	*data = be32_to_cpu(reg);

	return err;
	}

	static int set_clock(struct snd_tscm *tscm, unsigned int rate,
	enum snd_tscm_clock clock)
	{
	u32 data;
	__be32 reg;
	int err;

	err = get_clock(tscm, &data);
	if (err < 0)
	return err;
	data &= 0x0000ffff;

	if (rate > 0) {
	data &= 0x000000ff;
	/* Base rate. */
	if ((rate % 44100) == 0) {
	data \|= 0x00000100;
	/* Multiplier. */
	if (rate / 44100 == 2)
	data \|= 0x00008000;
	} else if ((rate % 48000) == 0) {
	data \|= 0x00000200;
	/* Multiplier. */
	if (rate / 48000 == 2)
	data \|= 0x00008000;
	} else {
	return -EAGAIN;
	}
	}

	if (clock != INT_MAX) {
	data &= 0x0000ff00;
	data \|= clock + 1;
	}

	reg = cpu_to_be32(data);

	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_CLOCK_STATUS,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	if (data & 0x00008000)
	reg = cpu_to_be32(0x0000001a);
	else
	reg = cpu_to_be32(0x0000000d);

	return snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_MULTIPLEX_MODE,
	&reg, sizeof(reg), 0);
	}

	int snd_tscm_stream_get_rate(struct snd_tscm tscm, unsigned int rate)
	{
	u32 data = 0x0;
	unsigned int trials = 0;
	int err;

	while (data == 0x0 \|\| trials++ < 5) {
	err = get_clock(tscm, &data);
	if (err < 0)
	return err;

	data = (data & 0xff000000) >> 24;
	}

	/* Check base rate. */
	if ((data & 0x0f) == 0x01)
	*rate = 44100;
	else if ((data & 0x0f) == 0x02)
	*rate = 48000;
	else
	return -EAGAIN;

	/* Check multiplier. */
	if ((data & 0xf0) == 0x80)
	rate = 2;
	else if ((data & 0xf0) != 0x00)
	return -EAGAIN;

	return err;
	}

	int snd_tscm_stream_get_clock(struct snd_tscm tscm, enum snd_tscm_clock clock)
	{
	u32 data;
	int err;

	err = get_clock(tscm, &data);
	if (err < 0)
	return err;

	*clock = ((data & 0x00ff0000) >> 16) - 1;
	if (clock < 0 \|\| clock > SND_TSCM_CLOCK_ADAT)
	return -EIO;

	return 0;
	}

	static int enable_data_channels(struct snd_tscm *tscm)
	{
	__be32 reg;
	u32 data;
	unsigned int i;
	int err;

	data = 0;
	for (i = 0; i < tscm->spec->pcm_capture_analog_channels; ++i)
	data \|= BIT(i);
	if (tscm->spec->has_adat)
	data \|= 0x0000ff00;
	if (tscm->spec->has_spdif)
	data \|= 0x00030000;

	reg = cpu_to_be32(data);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_TX_PCM_CHANNELS,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	data = 0;
	for (i = 0; i < tscm->spec->pcm_playback_analog_channels; ++i)
	data \|= BIT(i);
	if (tscm->spec->has_adat)
	data \|= 0x0000ff00;
	if (tscm->spec->has_spdif)
	data \|= 0x00030000;

	reg = cpu_to_be32(data);
	return snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_RX_PCM_CHANNELS,
	&reg, sizeof(reg), 0);
	}

	static int set_stream_formats(struct snd_tscm *tscm, unsigned int rate)
	{
	__be32 reg;
	int err;

	/* Set an option for unknown purpose. */
	reg = cpu_to_be32(0x00200000);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_SET_OPTION,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	err = enable_data_channels(tscm);
	if (err < 0)
	return err;

	return set_clock(tscm, rate, INT_MAX);
	}

	static void finish_session(struct snd_tscm *tscm)
	{
	__be32 reg;

	reg = 0;
	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_START_STREAMING,
	&reg, sizeof(reg), 0);

	reg = 0;
	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_ON,
	&reg, sizeof(reg), 0);

	}

	static int begin_session(struct snd_tscm *tscm)
	{
	__be32 reg;
	int err;

	reg = cpu_to_be32(0x00000001);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_START_STREAMING,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	reg = cpu_to_be32(0x00000001);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_ON,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	/* Set an option for unknown purpose. */
	reg = cpu_to_be32(0x00002000);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_SET_OPTION,
	&reg, sizeof(reg), 0);
	if (err < 0)
	return err;

	/* Start multiplexing PCM samples on packets. */
	reg = cpu_to_be32(0x00000001);
	return snd_fw_transaction(tscm->unit,
	TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_ON,
	&reg, sizeof(reg), 0);
	}

	static void release_resources(struct snd_tscm *tscm)
	{
	__be32 reg;

	/* Unregister channels. */
	reg = cpu_to_be32(0x00000000);
	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_CH,
	&reg, sizeof(reg), 0);
	reg = cpu_to_be32(0x00000000);
	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_UNKNOWN,
	&reg, sizeof(reg), 0);
	reg = cpu_to_be32(0x00000000);
	snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_CH,
	&reg, sizeof(reg), 0);

	/* Release isochronous resources. */
	fw_iso_resources_free(&tscm->tx_resources);
	fw_iso_resources_free(&tscm->rx_resources);
	}

	static int keep_resources(struct snd_tscm *tscm, unsigned int rate)
	{
	__be32 reg;
	int err;

	/* Keep resources for in-stream. */
	err = amdtp_tscm_set_parameters(&tscm->tx_stream, rate);
	if (err < 0)
	return err;
	err = fw_iso_resources_allocate(&tscm->tx_resources,
	amdtp_stream_get_max_payload(&tscm->tx_stream),
	fw_parent_device(tscm->unit)->max_speed);
	if (err < 0)
	goto error;

	/* Keep resources for out-stream. */
	err = amdtp_tscm_set_parameters(&tscm->rx_stream, rate);
	if (err < 0)
	return err;
	err = fw_iso_resources_allocate(&tscm->rx_resources,
	amdtp_stream_get_max_payload(&tscm->rx_stream),
	fw_parent_device(tscm->unit)->max_speed);
	if (err < 0)
	return err;

	/* Register the isochronous channel for transmitting stream. */
	reg = cpu_to_be32(tscm->tx_resources.channel);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_TX_CH,
	&reg, sizeof(reg), 0);
	if (err < 0)
	goto error;

	/* Unknown */
	reg = cpu_to_be32(0x00000002);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_UNKNOWN,
	&reg, sizeof(reg), 0);
	if (err < 0)
	goto error;

	/* Register the isochronous channel for receiving stream. */
	reg = cpu_to_be32(tscm->rx_resources.channel);
	err = snd_fw_transaction(tscm->unit, TCODE_WRITE_QUADLET_REQUEST,
	TSCM_ADDR_BASE + TSCM_OFFSET_ISOC_RX_CH,
	&reg, sizeof(reg), 0);
	if (err < 0)
	goto error;

	return 0;
	error:
	release_resources(tscm);
	return err;
	}

	int snd_tscm_stream_init_duplex(struct snd_tscm *tscm)
	{
	unsigned int pcm_channels;
	int err;

	/* For out-stream. */
	err = fw_iso_resources_init(&tscm->rx_resources, tscm->unit);
	if (err < 0)
	return err;
	pcm_channels = tscm->spec->pcm_playback_analog_channels;
	if (tscm->spec->has_adat)
	pcm_channels += 8;
	if (tscm->spec->has_spdif)
	pcm_channels += 2;
	err = amdtp_tscm_init(&tscm->rx_stream, tscm->unit, AMDTP_OUT_STREAM,
	pcm_channels);
	if (err < 0)
	return err;

	/* For in-stream. */
	err = fw_iso_resources_init(&tscm->tx_resources, tscm->unit);
	if (err < 0)
	return err;
	pcm_channels = tscm->spec->pcm_capture_analog_channels;
	if (tscm->spec->has_adat)
	pcm_channels += 8;
	if (tscm->spec->has_spdif)
	pcm_channels += 2;
	err = amdtp_tscm_init(&tscm->tx_stream, tscm->unit, AMDTP_IN_STREAM,
	pcm_channels);
	if (err < 0)
	amdtp_stream_destroy(&tscm->rx_stream);

	return err;
	}

	/* At bus reset, streaming is stopped and some registers are clear. */
	void snd_tscm_stream_update_duplex(struct snd_tscm *tscm)
	{
	amdtp_stream_pcm_abort(&tscm->tx_stream);
	amdtp_stream_stop(&tscm->tx_stream);

	amdtp_stream_pcm_abort(&tscm->rx_stream);
	amdtp_stream_stop(&tscm->rx_stream);
	}

	/*
	* This function should be called before starting streams or after stopping
	* streams.
	*/
	void snd_tscm_stream_destroy_duplex(struct snd_tscm *tscm)
	{
	amdtp_stream_destroy(&tscm->rx_stream);
	amdtp_stream_destroy(&tscm->tx_stream);

	fw_iso_resources_destroy(&tscm->rx_resources);
	fw_iso_resources_destroy(&tscm->tx_resources);
	}

	int snd_tscm_stream_start_duplex(struct snd_tscm *tscm, unsigned int rate)
	{
	unsigned int curr_rate;
	int err;

	if (tscm->substreams_counter == 0)
	return 0;

	err = snd_tscm_stream_get_rate(tscm, &curr_rate);
	if (err < 0)
	return err;
	if (curr_rate != rate \|\|
	amdtp_streaming_error(&tscm->rx_stream) \|\|
	amdtp_streaming_error(&tscm->tx_stream)) {
	finish_session(tscm);

	amdtp_stream_stop(&tscm->rx_stream);
	amdtp_stream_stop(&tscm->tx_stream);

	release_resources(tscm);
	}

	if (!amdtp_stream_running(&tscm->rx_stream)) {
	err = keep_resources(tscm, rate);
	if (err < 0)
	goto error;

	err = set_stream_formats(tscm, rate);
	if (err < 0)
	goto error;

	err = begin_session(tscm);
	if (err < 0)
	goto error;

	err = amdtp_stream_start(&tscm->rx_stream,
	tscm->rx_resources.channel,
	fw_parent_device(tscm->unit)->max_speed);
	if (err < 0)
	goto error;

	if (!amdtp_stream_wait_callback(&tscm->rx_stream,
	CALLBACK_TIMEOUT)) {
	err = -ETIMEDOUT;
	goto error;
	}
	}

	if (!amdtp_stream_running(&tscm->tx_stream)) {
	err = amdtp_stream_start(&tscm->tx_stream,
	tscm->tx_resources.channel,
	fw_parent_device(tscm->unit)->max_speed);
	if (err < 0)
	goto error;

	if (!amdtp_stream_wait_callback(&tscm->tx_stream,
	CALLBACK_TIMEOUT)) {
	err = -ETIMEDOUT;
	goto error;
	}
	}

	return 0;
	error:
	amdtp_stream_stop(&tscm->rx_stream);
	amdtp_stream_stop(&tscm->tx_stream);

	finish_session(tscm);
	release_resources(tscm);

	return err;
	}

	void snd_tscm_stream_stop_duplex(struct snd_tscm *tscm)
	{
	if (tscm->substreams_counter > 0)
	return;

	amdtp_stream_stop(&tscm->tx_stream);
	amdtp_stream_stop(&tscm->rx_stream);

	finish_session(tscm);
	release_resources(tscm);
	}

	void snd_tscm_stream_lock_changed(struct snd_tscm *tscm)
	{
	tscm->dev_lock_changed = true;
	wake_up(&tscm->hwdep_wait);
	}

	int snd_tscm_stream_lock_try(struct snd_tscm *tscm)
	{
	int err;

	spin_lock_irq(&tscm->lock);

	/* user land lock this */
	if (tscm->dev_lock_count < 0) {
	err = -EBUSY;
	goto end;
	}

	/* this is the first time */
	if (tscm->dev_lock_count++ == 0)
	snd_tscm_stream_lock_changed(tscm);
	err = 0;
	end:
	spin_unlock_irq(&tscm->lock);
	return err;
	}

	void snd_tscm_stream_lock_release(struct snd_tscm *tscm)
	{
	spin_lock_irq(&tscm->lock);

	if (WARN_ON(tscm->dev_lock_count <= 0))
	goto end;
	if (--tscm->dev_lock_count == 0)
	snd_tscm_stream_lock_changed(tscm);
	end:
	spin_unlock_irq(&tscm->lock);
	}