Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 846 insertions, 0 deletions

diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
new file mode 100644
index 0000000000..f4a702def3
--- /dev/null
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -0,0 +1,846 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * oxfw_stream.c - a part of driver for OXFW970/971 based devices
+ *
+ * Copyright (c) 2014 Takashi Sakamoto
+ */
+
+#include "oxfw.h"
+#include <linux/delay.h>
+
+#define AVC_GENERIC_FRAME_MAXIMUM_BYTES	512
+#define READY_TIMEOUT_MS	600
+
+/*
+ * According to datasheet of Oxford Semiconductor:
+ *  OXFW970: 32.0/44.1/48.0/96.0 Khz, 8 audio channels I/O
+ *  OXFW971: 32.0/44.1/48.0/88.2/96.0/192.0 kHz, 16 audio channels I/O, MIDI I/O
+ */
+static const unsigned int oxfw_rate_table[] = {
+	[0] = 32000,
+	[1] = 44100,
+	[2] = 48000,
+	[3] = 88200,
+	[4] = 96000,
+	[5] = 192000,
+};
+
+/*
+ * See Table 5.7 – Sampling frequency for Multi-bit Audio
+ * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
+ */
+static const unsigned int avc_stream_rate_table[] = {
+	[0] = 0x02,
+	[1] = 0x03,
+	[2] = 0x04,
+	[3] = 0x0a,
+	[4] = 0x05,
+	[5] = 0x07,
+};
+
+static int set_rate(struct snd_oxfw *oxfw, unsigned int rate)
+{
+	int err;
+
+	err = avc_general_set_sig_fmt(oxfw->unit, rate,
+				      AVC_GENERAL_PLUG_DIR_IN, 0);
+	if (err < 0)
+		goto end;
+
+	if (oxfw->has_output)
+		err = avc_general_set_sig_fmt(oxfw->unit, rate,
+					      AVC_GENERAL_PLUG_DIR_OUT, 0);
+end:
+	return err;
+}
+
+static int set_stream_format(struct snd_oxfw *oxfw, struct amdtp_stream *s,
+			     unsigned int rate, unsigned int pcm_channels)
+{
+	u8 **formats;
+	struct snd_oxfw_stream_formation formation;
+	enum avc_general_plug_dir dir;
+	unsigned int len;
+	int i, err;
+
+	if (s == &oxfw->tx_stream) {
+		formats = oxfw->tx_stream_formats;
+		dir = AVC_GENERAL_PLUG_DIR_OUT;
+	} else {
+		formats = oxfw->rx_stream_formats;
+		dir = AVC_GENERAL_PLUG_DIR_IN;
+	}
+
+	/* Seek stream format for requirements. */
+	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+		err = snd_oxfw_stream_parse_format(formats[i], &formation);
+		if (err < 0)
+			return err;
+
+		if ((formation.rate == rate) && (formation.pcm == pcm_channels))
+			break;
+	}
+	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
+		return -EINVAL;
+
+	/* If assumed, just change rate. */
+	if (oxfw->assumed)
+		return set_rate(oxfw, rate);
+
+	/* Calculate format length. */
+	len = 5 + formats[i][4] * 2;
+
+	err = avc_stream_set_format(oxfw->unit, dir, 0, formats[i], len);
+	if (err < 0)
+		return err;
+
+	/* Some requests just after changing format causes freezing. */
+	msleep(100);
+
+	return 0;
+}
+
+static int start_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
+{
+	struct cmp_connection *conn;
+	int err;
+
+	if (stream == &oxfw->rx_stream)
+		conn = &oxfw->in_conn;
+	else
+		conn = &oxfw->out_conn;
+
+	err = cmp_connection_establish(conn);
+	if (err < 0)
+		return err;
+
+	err = amdtp_domain_add_stream(&oxfw->domain, stream,
+				      conn->resources.channel, conn->speed);
+	if (err < 0) {
+		cmp_connection_break(conn);
+		return err;
+	}
+
+	return 0;
+}
+
+static int check_connection_used_by_others(struct snd_oxfw *oxfw,
+					   struct amdtp_stream *stream)
+{
+	struct cmp_connection *conn;
+	bool used;
+	int err;
+
+	if (stream == &oxfw->tx_stream)
+		conn = &oxfw->out_conn;
+	else
+		conn = &oxfw->in_conn;
+
+	err = cmp_connection_check_used(conn, &used);
+	if ((err >= 0) && used && !amdtp_stream_running(stream)) {
+		dev_err(&oxfw->unit->device,
+			"Connection established by others: %cPCR[%d]\n",
+			(conn->direction == CMP_OUTPUT) ? 'o' : 'i',
+			conn->pcr_index);
+		err = -EBUSY;
+	}
+
+	return err;
+}
+
+static int init_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
+{
+	struct cmp_connection *conn;
+	enum cmp_direction c_dir;
+	enum amdtp_stream_direction s_dir;
+	unsigned int flags = 0;
+	int err;
+
+	if (!(oxfw->quirks & SND_OXFW_QUIRK_BLOCKING_TRANSMISSION))
+		flags |= CIP_NONBLOCKING;
+	else
+		flags |= CIP_BLOCKING;
+
+	// OXFW 970/971 has no function to generate playback timing according to the sequence
+	// of value in syt field, thus the packet should include NO_INFO value in the field.
+	// However, some models just ignore data blocks in packet with NO_INFO for audio data
+	// processing.
+	if (!(oxfw->quirks & SND_OXFW_QUIRK_IGNORE_NO_INFO_PACKET))
+		flags |= CIP_UNAWARE_SYT;
+
+	if (stream == &oxfw->tx_stream) {
+		conn = &oxfw->out_conn;
+		c_dir = CMP_OUTPUT;
+		s_dir = AMDTP_IN_STREAM;
+
+		if (oxfw->quirks & SND_OXFW_QUIRK_JUMBO_PAYLOAD)
+			flags |= CIP_JUMBO_PAYLOAD;
+		if (oxfw->quirks & SND_OXFW_QUIRK_WRONG_DBS)
+			flags |= CIP_WRONG_DBS;
+	} else {
+		conn = &oxfw->in_conn;
+		c_dir = CMP_INPUT;
+		s_dir = AMDTP_OUT_STREAM;
+	}
+
+	err = cmp_connection_init(conn, oxfw->unit, c_dir, 0);
+	if (err < 0)
+		return err;
+
+	err = amdtp_am824_init(stream, oxfw->unit, s_dir, flags);
+	if (err < 0) {
+		cmp_connection_destroy(conn);
+		return err;
+	}
+
+	return 0;
+}
+
+static int keep_resources(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
+{
+	enum avc_general_plug_dir dir;
+	u8 **formats;
+	struct snd_oxfw_stream_formation formation;
+	struct cmp_connection *conn;
+	int i;
+	int err;
+
+	if (stream == &oxfw->rx_stream) {
+		dir = AVC_GENERAL_PLUG_DIR_IN;
+		formats = oxfw->rx_stream_formats;
+		conn = &oxfw->in_conn;
+	} else {
+		dir = AVC_GENERAL_PLUG_DIR_OUT;
+		formats = oxfw->tx_stream_formats;
+		conn = &oxfw->out_conn;
+	}
+
+	err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+		struct snd_oxfw_stream_formation fmt;
+
+		if (formats[i] == NULL)
+			break;
+
+		err = snd_oxfw_stream_parse_format(formats[i], &fmt);
+		if (err < 0)
+			return err;
+
+		if (fmt.rate == formation.rate && fmt.pcm == formation.pcm &&
+		    fmt.midi == formation.midi)
+			break;
+	}
+	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
+		return -EINVAL;
+
+	// The stream should have one pcm channels at least.
+	if (formation.pcm == 0)
+		return -EINVAL;
+
+	err = amdtp_am824_set_parameters(stream, formation.rate, formation.pcm,
+					 formation.midi * 8, false);
+	if (err < 0)
+		return err;
+
+	return cmp_connection_reserve(conn, amdtp_stream_get_max_payload(stream));
+}
+
+int snd_oxfw_stream_reserve_duplex(struct snd_oxfw *oxfw,
+				   struct amdtp_stream *stream,
+				   unsigned int rate, unsigned int pcm_channels,
+				   unsigned int frames_per_period,
+				   unsigned int frames_per_buffer)
+{
+	struct snd_oxfw_stream_formation formation;
+	enum avc_general_plug_dir dir;
+	int err;
+
+	// Considering JACK/FFADO streaming:
+	// TODO: This can be removed hwdep functionality becomes popular.
+	err = check_connection_used_by_others(oxfw, &oxfw->rx_stream);
+	if (err < 0)
+		return err;
+	if (oxfw->has_output) {
+		err = check_connection_used_by_others(oxfw, &oxfw->tx_stream);
+		if (err < 0)
+			return err;
+	}
+
+	if (stream == &oxfw->tx_stream)
+		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)
+		return err;
+	if (rate == 0) {
+		rate = formation.rate;
+		pcm_channels = formation.pcm;
+	}
+	if (formation.rate != rate || formation.pcm != pcm_channels) {
+		amdtp_domain_stop(&oxfw->domain);
+
+		cmp_connection_break(&oxfw->in_conn);
+		cmp_connection_release(&oxfw->in_conn);
+
+		if (oxfw->has_output) {
+			cmp_connection_break(&oxfw->out_conn);
+			cmp_connection_release(&oxfw->out_conn);
+		}
+	}
+
+	if (oxfw->substreams_count == 0 ||
+	    formation.rate != rate || formation.pcm != pcm_channels) {
+		err = set_stream_format(oxfw, stream, rate, pcm_channels);
+		if (err < 0) {
+			dev_err(&oxfw->unit->device,
+				"fail to set stream format: %d\n", err);
+			return err;
+		}
+
+		err = keep_resources(oxfw, &oxfw->rx_stream);
+		if (err < 0)
+			return err;
+
+		if (oxfw->has_output) {
+			err = keep_resources(oxfw, &oxfw->tx_stream);
+			if (err < 0) {
+				cmp_connection_release(&oxfw->in_conn);
+				return err;
+			}
+		}
+
+		err = amdtp_domain_set_events_per_period(&oxfw->domain,
+					frames_per_period, frames_per_buffer);
+		if (err < 0) {
+			cmp_connection_release(&oxfw->in_conn);
+			if (oxfw->has_output)
+				cmp_connection_release(&oxfw->out_conn);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+int snd_oxfw_stream_start_duplex(struct snd_oxfw *oxfw)
+{
+	int err;
+
+	if (oxfw->substreams_count == 0)
+		return -EIO;
+
+	if (amdtp_streaming_error(&oxfw->rx_stream) ||
+	    amdtp_streaming_error(&oxfw->tx_stream)) {
+		amdtp_domain_stop(&oxfw->domain);
+
+		cmp_connection_break(&oxfw->in_conn);
+		if (oxfw->has_output)
+			cmp_connection_break(&oxfw->out_conn);
+	}
+
+	if (!amdtp_stream_running(&oxfw->rx_stream)) {
+		unsigned int tx_init_skip_cycles = 0;
+		bool replay_seq = false;
+
+		err = start_stream(oxfw, &oxfw->rx_stream);
+		if (err < 0) {
+			dev_err(&oxfw->unit->device,
+				"fail to prepare rx stream: %d\n", err);
+			goto error;
+		}
+
+		if (oxfw->has_output &&
+		    !amdtp_stream_running(&oxfw->tx_stream)) {
+			err = start_stream(oxfw, &oxfw->tx_stream);
+			if (err < 0) {
+				dev_err(&oxfw->unit->device,
+					"fail to prepare tx stream: %d\n", err);
+				goto error;
+			}
+
+			if (oxfw->quirks & SND_OXFW_QUIRK_JUMBO_PAYLOAD) {
+				// Just after changing sampling transfer frequency, many cycles are
+				// skipped for packet transmission.
+				tx_init_skip_cycles = 400;
+			} else if (oxfw->quirks & SND_OXFW_QUIRK_VOLUNTARY_RECOVERY) {
+				// It takes a bit time for target device to adjust event frequency
+				// according to nominal event frequency in isochronous packets from
+				// ALSA oxfw driver.
+				tx_init_skip_cycles = 4000;
+			} else {
+				replay_seq = true;
+			}
+		}
+
+		// NOTE: The device ignores presentation time expressed by the value of syt field
+		// of CIP header in received packets. The sequence of the number of data blocks per
+		// packet is important for media clock recovery.
+		err = amdtp_domain_start(&oxfw->domain, tx_init_skip_cycles, replay_seq, false);
+		if (err < 0)
+			goto error;
+
+		if (!amdtp_domain_wait_ready(&oxfw->domain, READY_TIMEOUT_MS)) {
+			err = -ETIMEDOUT;
+			goto error;
+		}
+	}
+
+	return 0;
+error:
+	amdtp_domain_stop(&oxfw->domain);
+
+	cmp_connection_break(&oxfw->in_conn);
+	if (oxfw->has_output)
+		cmp_connection_break(&oxfw->out_conn);
+
+	return err;
+}
+
+void snd_oxfw_stream_stop_duplex(struct snd_oxfw *oxfw)
+{
+	if (oxfw->substreams_count == 0) {
+		amdtp_domain_stop(&oxfw->domain);
+
+		cmp_connection_break(&oxfw->in_conn);
+		cmp_connection_release(&oxfw->in_conn);
+
+		if (oxfw->has_output) {
+			cmp_connection_break(&oxfw->out_conn);
+			cmp_connection_release(&oxfw->out_conn);
+		}
+	}
+}
+
+static void destroy_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
+{
+	struct cmp_connection *conn;
+
+	if (stream == &oxfw->tx_stream)
+		conn = &oxfw->out_conn;
+	else
+		conn = &oxfw->in_conn;
+
+	amdtp_stream_destroy(stream);
+	cmp_connection_destroy(conn);
+}
+
+int snd_oxfw_stream_init_duplex(struct snd_oxfw *oxfw)
+{
+	int err;
+
+	err = init_stream(oxfw, &oxfw->rx_stream);
+	if (err < 0)
+		return err;
+
+	if (oxfw->has_output) {
+		err = init_stream(oxfw, &oxfw->tx_stream);
+		if (err < 0) {
+			destroy_stream(oxfw, &oxfw->rx_stream);
+			return err;
+		}
+	}
+
+	err = amdtp_domain_init(&oxfw->domain);
+	if (err < 0) {
+		destroy_stream(oxfw, &oxfw->rx_stream);
+		if (oxfw->has_output)
+			destroy_stream(oxfw, &oxfw->tx_stream);
+	}
+
+	return err;
+}
+
+// This function should be called before starting the stream or after stopping
+// the streams.
+void snd_oxfw_stream_destroy_duplex(struct snd_oxfw *oxfw)
+{
+	amdtp_domain_destroy(&oxfw->domain);
+
+	destroy_stream(oxfw, &oxfw->rx_stream);
+
+	if (oxfw->has_output)
+		destroy_stream(oxfw, &oxfw->tx_stream);
+}
+
+void snd_oxfw_stream_update_duplex(struct snd_oxfw *oxfw)
+{
+	amdtp_domain_stop(&oxfw->domain);
+
+	cmp_connection_break(&oxfw->in_conn);
+
+	amdtp_stream_pcm_abort(&oxfw->rx_stream);
+
+	if (oxfw->has_output) {
+		cmp_connection_break(&oxfw->out_conn);
+
+		amdtp_stream_pcm_abort(&oxfw->tx_stream);
+	}
+}
+
+int snd_oxfw_stream_get_current_formation(struct snd_oxfw *oxfw,
+				enum avc_general_plug_dir dir,
+				struct snd_oxfw_stream_formation *formation)
+{
+	u8 *format;
+	unsigned int len;
+	int err;
+
+	len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
+	format = kmalloc(len, GFP_KERNEL);
+	if (format == NULL)
+		return -ENOMEM;
+
+	err = avc_stream_get_format_single(oxfw->unit, dir, 0, format, &len);
+	if (err < 0)
+		goto end;
+	if (len < 3) {
+		err = -EIO;
+		goto end;
+	}
+
+	err = snd_oxfw_stream_parse_format(format, formation);
+end:
+	kfree(format);
+	return err;
+}
+
+/*
+ * See Table 6.16 - AM824 Stream Format
+ *     Figure 6.19 - format_information field for AM824 Compound
+ * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
+ * Also 'Clause 12 AM824 sequence adaption layers' in IEC 61883-6:2005
+ */
+int snd_oxfw_stream_parse_format(u8 *format,
+				 struct snd_oxfw_stream_formation *formation)
+{
+	unsigned int i, e, channels, type;
+
+	memset(formation, 0, sizeof(struct snd_oxfw_stream_formation));
+
+	/*
+	 * this module can support a hierarchy combination that:
+	 *  Root:	Audio and Music (0x90)
+	 *  Level 1:	AM824 Compound  (0x40)
+	 */
+	if ((format[0] != 0x90) || (format[1] != 0x40))
+		return -ENXIO;
+
+	/* check the sampling rate */
+	for (i = 0; i < ARRAY_SIZE(avc_stream_rate_table); i++) {
+		if (format[2] == avc_stream_rate_table[i])
+			break;
+	}
+	if (i == ARRAY_SIZE(avc_stream_rate_table))
+		return -ENXIO;
+
+	formation->rate = oxfw_rate_table[i];
+
+	for (e = 0; e < format[4]; e++) {
+		channels = format[5 + e * 2];
+		type = format[6 + e * 2];
+
+		switch (type) {
+		/* IEC 60958 Conformant, currently handled as MBLA */
+		case 0x00:
+		/* Multi Bit Linear Audio (Raw) */
+		case 0x06:
+			formation->pcm += channels;
+			break;
+		/* MIDI Conformant */
+		case 0x0d:
+			formation->midi = channels;
+			break;
+		/* IEC 61937-3 to 7 */
+		case 0x01:
+		case 0x02:
+		case 0x03:
+		case 0x04:
+		case 0x05:
+		/* Multi Bit Linear Audio */
+		case 0x07:	/* DVD-Audio */
+		case 0x0c:	/* High Precision */
+		/* One Bit Audio */
+		case 0x08:	/* (Plain) Raw */
+		case 0x09:	/* (Plain) SACD */
+		case 0x0a:	/* (Encoded) Raw */
+		case 0x0b:	/* (Encoded) SACD */
+		/* SMPTE Time-Code conformant */
+		case 0x0e:
+		/* Sample Count */
+		case 0x0f:
+		/* Anciliary Data */
+		case 0x10:
+		/* Synchronization Stream (Stereo Raw audio) */
+		case 0x40:
+		/* Don't care */
+		case 0xff:
+		default:
+			return -ENXIO;	/* not supported */
+		}
+	}
+
+	if (formation->pcm  > AM824_MAX_CHANNELS_FOR_PCM ||
+	    formation->midi > AM824_MAX_CHANNELS_FOR_MIDI)
+		return -ENXIO;
+
+	return 0;
+}
+
+static int
+assume_stream_formats(struct snd_oxfw *oxfw, enum avc_general_plug_dir dir,
+		      unsigned int pid, u8 *buf, unsigned int *len,
+		      u8 **formats)
+{
+	struct snd_oxfw_stream_formation formation;
+	unsigned int i, eid;
+	int err;
+
+	/* get format at current sampling rate */
+	err = avc_stream_get_format_single(oxfw->unit, dir, pid, buf, len);
+	if (err < 0) {
+		dev_err(&oxfw->unit->device,
+		"fail to get current stream format for isoc %s plug %d:%d\n",
+			(dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
+			pid, err);
+		goto end;
+	}
+
+	/* parse and set stream format */
+	eid = 0;
+	err = snd_oxfw_stream_parse_format(buf, &formation);
+	if (err < 0)
+		goto end;
+
+	formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, *len,
+				    GFP_KERNEL);
+	if (!formats[eid]) {
+		err = -ENOMEM;
+		goto end;
+	}
+
+	/* apply the format for each available sampling rate */
+	for (i = 0; i < ARRAY_SIZE(oxfw_rate_table); i++) {
+		if (formation.rate == oxfw_rate_table[i])
+			continue;
+
+		err = avc_general_inquiry_sig_fmt(oxfw->unit,
+						  oxfw_rate_table[i],
+						  dir, pid);
+		if (err < 0)
+			continue;
+
+		eid++;
+		formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, *len,
+					    GFP_KERNEL);
+		if (formats[eid] == NULL) {
+			err = -ENOMEM;
+			goto end;
+		}
+		formats[eid][2] = avc_stream_rate_table[i];
+	}
+
+	err = 0;
+	oxfw->assumed = true;
+end:
+	return err;
+}
+
+static int fill_stream_formats(struct snd_oxfw *oxfw,
+			       enum avc_general_plug_dir dir,
+			       unsigned short pid)
+{
+	u8 *buf, **formats;
+	unsigned int len, eid = 0;
+	struct snd_oxfw_stream_formation dummy;
+	int err;
+
+	buf = kmalloc(AVC_GENERIC_FRAME_MAXIMUM_BYTES, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	if (dir == AVC_GENERAL_PLUG_DIR_OUT)
+		formats = oxfw->tx_stream_formats;
+	else
+		formats = oxfw->rx_stream_formats;
+
+	/* get first entry */
+	len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
+	err = avc_stream_get_format_list(oxfw->unit, dir, 0, buf, &len, 0);
+	if (err == -ENXIO) {
+		/* LIST subfunction is not implemented */
+		len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
+		err = assume_stream_formats(oxfw, dir, pid, buf, &len,
+					    formats);
+		goto end;
+	} else if (err < 0) {
+		dev_err(&oxfw->unit->device,
+			"fail to get stream format %d for isoc %s plug %d:%d\n",
+			eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
+			pid, err);
+		goto end;
+	}
+
+	/* LIST subfunction is implemented */
+	while (eid < SND_OXFW_STREAM_FORMAT_ENTRIES) {
+		/* The format is too short. */
+		if (len < 3) {
+			err = -EIO;
+			break;
+		}
+
+		/* parse and set stream format */
+		err = snd_oxfw_stream_parse_format(buf, &dummy);
+		if (err < 0)
+			break;
+
+		formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, len,
+					    GFP_KERNEL);
+		if (!formats[eid]) {
+			err = -ENOMEM;
+			break;
+		}
+
+		/* get next entry */
+		len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
+		err = avc_stream_get_format_list(oxfw->unit, dir, 0,
+						 buf, &len, ++eid);
+		/* No entries remained. */
+		if (err == -EINVAL) {
+			err = 0;
+			break;
+		} else if (err < 0) {
+			dev_err(&oxfw->unit->device,
+			"fail to get stream format %d for isoc %s plug %d:%d\n",
+				eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" :
+									"out",
+				pid, err);
+			break;
+		}
+	}
+end:
+	kfree(buf);
+	return err;
+}
+
+int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
+{
+	u8 plugs[AVC_PLUG_INFO_BUF_BYTES];
+	struct snd_oxfw_stream_formation formation;
+	u8 *format;
+	unsigned int i;
+	int err;
+
+	/* the number of plugs for isoc in/out, ext in/out  */
+	err = avc_general_get_plug_info(oxfw->unit, 0x1f, 0x07, 0x00, plugs);
+	if (err < 0) {
+		dev_err(&oxfw->unit->device,
+		"fail to get info for isoc/external in/out plugs: %d\n",
+			err);
+		goto end;
+	} else if ((plugs[0] == 0) && (plugs[1] == 0)) {
+		err = -ENXIO;
+		goto end;
+	}
+
+	/* use oPCR[0] if exists */
+	if (plugs[1] > 0) {
+		err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_OUT, 0);
+		if (err < 0) {
+			if (err != -ENXIO)
+				return err;
+
+			// The oPCR is not available for isoc communication.
+			err = 0;
+		} else {
+			for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+				format = oxfw->tx_stream_formats[i];
+				if (format == NULL)
+					continue;
+				err = snd_oxfw_stream_parse_format(format,
+								   &formation);
+				if (err < 0)
+					continue;
+
+				/* Add one MIDI port. */
+				if (formation.midi > 0)
+					oxfw->midi_input_ports = 1;
+			}
+
+			oxfw->has_output = true;
+		}
+	}
+
+	/* use iPCR[0] if exists */
+	if (plugs[0] > 0) {
+		err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_IN, 0);
+		if (err < 0) {
+			if (err != -ENXIO)
+				return err;
+
+			// The iPCR is not available for isoc communication.
+			err = 0;
+		} else {
+			for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+				format = oxfw->rx_stream_formats[i];
+				if (format == NULL)
+					continue;
+				err = snd_oxfw_stream_parse_format(format,
+								   &formation);
+				if (err < 0)
+					continue;
+
+				/* Add one MIDI port. */
+				if (formation.midi > 0)
+					oxfw->midi_output_ports = 1;
+			}
+
+			oxfw->has_input = true;
+		}
+	}
+end:
+	return err;
+}
+
+void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
+{
+	oxfw->dev_lock_changed = true;
+	wake_up(&oxfw->hwdep_wait);
+}
+
+int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
+{
+	int err;
+
+	spin_lock_irq(&oxfw->lock);
+
+	/* user land lock this */
+	if (oxfw->dev_lock_count < 0) {
+		err = -EBUSY;
+		goto end;
+	}
+
+	/* this is the first time */
+	if (oxfw->dev_lock_count++ == 0)
+		snd_oxfw_stream_lock_changed(oxfw);
+	err = 0;
+end:
+	spin_unlock_irq(&oxfw->lock);
+	return err;
+}
+
+void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
+{
+	spin_lock_irq(&oxfw->lock);
+
+	if (WARN_ON(oxfw->dev_lock_count <= 0))
+		goto end;
+	if (--oxfw->dev_lock_count == 0)
+		snd_oxfw_stream_lock_changed(oxfw);
+end:
+	spin_unlock_irq(&oxfw->lock);
+}