Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 996 insertions, 0 deletions

diff --git a/sound/firewire/bebob/bebob_stream.c b/sound/firewire/bebob/bebob_stream.c
new file mode 100644
index 000000000..8629b14de
--- /dev/null
+++ b/sound/firewire/bebob/bebob_stream.c
@@ -0,0 +1,996 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * bebob_stream.c - a part of driver for BeBoB based devices
+ *
+ * Copyright (c) 2013-2014 Takashi Sakamoto
+ */
+
+#include "./bebob.h"
+
+#define READY_TIMEOUT_MS	4000
+
+/*
+ * NOTE;
+ * For BeBoB streams, Both of input and output CMP connection are important.
+ *
+ * For most devices, each CMP connection starts to transmit/receive a
+ * corresponding stream. But for a few devices, both of CMP connection needs
+ * to start transmitting stream. An example is 'M-Audio Firewire 410'.
+ */
+
+/* 128 is an arbitrary length but it seems to be enough */
+#define FORMAT_MAXIMUM_LENGTH 128
+
+const unsigned int snd_bebob_rate_table[SND_BEBOB_STRM_FMT_ENTRIES] = {
+	[0] = 32000,
+	[1] = 44100,
+	[2] = 48000,
+	[3] = 88200,
+	[4] = 96000,
+	[5] = 176400,
+	[6] = 192000,
+};
+
+/*
+ * See: Table 51: Extended Stream Format Info ‘Sampling Frequency’
+ * in Additional AVC commands (Nov 2003, BridgeCo)
+ */
+static const unsigned int bridgeco_freq_table[] = {
+	[0] = 0x02,
+	[1] = 0x03,
+	[2] = 0x04,
+	[3] = 0x0a,
+	[4] = 0x05,
+	[5] = 0x06,
+	[6] = 0x07,
+};
+
+static int
+get_formation_index(unsigned int rate, unsigned int *index)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(snd_bebob_rate_table); i++) {
+		if (snd_bebob_rate_table[i] == rate) {
+			*index = i;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+int
+snd_bebob_stream_get_rate(struct snd_bebob *bebob, unsigned int *curr_rate)
+{
+	unsigned int tx_rate, rx_rate, trials;
+	int err;
+
+	trials = 0;
+	do {
+		err = avc_general_get_sig_fmt(bebob->unit, &tx_rate,
+					      AVC_GENERAL_PLUG_DIR_OUT, 0);
+	} while (err == -EAGAIN && ++trials < 3);
+	if (err < 0)
+		goto end;
+
+	trials = 0;
+	do {
+		err = avc_general_get_sig_fmt(bebob->unit, &rx_rate,
+					      AVC_GENERAL_PLUG_DIR_IN, 0);
+	} while (err == -EAGAIN && ++trials < 3);
+	if (err < 0)
+		goto end;
+
+	*curr_rate = rx_rate;
+	if (rx_rate == tx_rate)
+		goto end;
+
+	/* synchronize receive stream rate to transmit stream rate */
+	err = avc_general_set_sig_fmt(bebob->unit, rx_rate,
+				      AVC_GENERAL_PLUG_DIR_IN, 0);
+end:
+	return err;
+}
+
+int
+snd_bebob_stream_set_rate(struct snd_bebob *bebob, unsigned int rate)
+{
+	int err;
+
+	err = avc_general_set_sig_fmt(bebob->unit, rate,
+				      AVC_GENERAL_PLUG_DIR_OUT, 0);
+	if (err < 0)
+		goto end;
+
+	err = avc_general_set_sig_fmt(bebob->unit, rate,
+				      AVC_GENERAL_PLUG_DIR_IN, 0);
+	if (err < 0)
+		goto end;
+
+	/*
+	 * Some devices need a bit time for transition.
+	 * 300msec is got by some experiments.
+	 */
+	msleep(300);
+end:
+	return err;
+}
+
+int snd_bebob_stream_get_clock_src(struct snd_bebob *bebob,
+				   enum snd_bebob_clock_type *src)
+{
+	const struct snd_bebob_clock_spec *clk_spec = bebob->spec->clock;
+	u8 addr[AVC_BRIDGECO_ADDR_BYTES], input[7];
+	unsigned int id;
+	enum avc_bridgeco_plug_type type;
+	int err = 0;
+
+	/* 1.The device has its own operation to switch source of clock */
+	if (clk_spec) {
+		err = clk_spec->get(bebob, &id);
+		if (err < 0) {
+			dev_err(&bebob->unit->device,
+				"fail to get clock source: %d\n", err);
+			goto end;
+		}
+
+		if (id >= clk_spec->num) {
+			dev_err(&bebob->unit->device,
+				"clock source %d out of range 0..%d\n",
+				id, clk_spec->num - 1);
+			err = -EIO;
+			goto end;
+		}
+
+		*src = clk_spec->types[id];
+		goto end;
+	}
+
+	/*
+	 * 2.The device don't support to switch source of clock then assumed
+	 *   to use internal clock always
+	 */
+	if (bebob->sync_input_plug < 0) {
+		*src = SND_BEBOB_CLOCK_TYPE_INTERNAL;
+		goto end;
+	}
+
+	/*
+	 * 3.The device supports to switch source of clock by an usual way.
+	 *   Let's check input for 'Music Sub Unit Sync Input' plug.
+	 */
+	avc_bridgeco_fill_msu_addr(addr, AVC_BRIDGECO_PLUG_DIR_IN,
+				   bebob->sync_input_plug);
+	err = avc_bridgeco_get_plug_input(bebob->unit, addr, input);
+	if (err < 0) {
+		dev_err(&bebob->unit->device,
+			"fail to get an input for MSU in plug %d: %d\n",
+			bebob->sync_input_plug, err);
+		goto end;
+	}
+
+	/*
+	 * If there are no input plugs, all of fields are 0xff.
+	 * Here check the first field. This field is used for direction.
+	 */
+	if (input[0] == 0xff) {
+		*src = SND_BEBOB_CLOCK_TYPE_INTERNAL;
+		goto end;
+	}
+
+	/* The source from any output plugs is for one purpose only. */
+	if (input[0] == AVC_BRIDGECO_PLUG_DIR_OUT) {
+		/*
+		 * In BeBoB architecture, the source from music subunit may
+		 * bypass from oPCR[0]. This means that this source gives
+		 * synchronization to IEEE 1394 cycle start packet.
+		 */
+		if (input[1] == AVC_BRIDGECO_PLUG_MODE_SUBUNIT &&
+		    input[2] == 0x0c) {
+			*src = SND_BEBOB_CLOCK_TYPE_INTERNAL;
+			goto end;
+		}
+	/* The source from any input units is for several purposes. */
+	} else if (input[1] == AVC_BRIDGECO_PLUG_MODE_UNIT) {
+		if (input[2] == AVC_BRIDGECO_PLUG_UNIT_ISOC) {
+			if (input[3] == 0x00) {
+				/*
+				 * This source comes from iPCR[0]. This means
+				 * that presentation timestamp calculated by
+				 * SYT series of the received packets. In
+				 * short, this driver is the master of
+				 * synchronization.
+				 */
+				*src = SND_BEBOB_CLOCK_TYPE_SYT;
+				goto end;
+			} else {
+				/*
+				 * This source comes from iPCR[1-29]. This
+				 * means that the synchronization stream is not
+				 * the Audio/MIDI compound stream.
+				 */
+				*src = SND_BEBOB_CLOCK_TYPE_EXTERNAL;
+				goto end;
+			}
+		} else if (input[2] == AVC_BRIDGECO_PLUG_UNIT_EXT) {
+			/* Check type of this plug.  */
+			avc_bridgeco_fill_unit_addr(addr,
+						    AVC_BRIDGECO_PLUG_DIR_IN,
+						    AVC_BRIDGECO_PLUG_UNIT_EXT,
+						    input[3]);
+			err = avc_bridgeco_get_plug_type(bebob->unit, addr,
+							 &type);
+			if (err < 0)
+				goto end;
+
+			if (type == AVC_BRIDGECO_PLUG_TYPE_DIG) {
+				/*
+				 * SPDIF/ADAT or sometimes (not always) word
+				 * clock.
+				 */
+				*src = SND_BEBOB_CLOCK_TYPE_EXTERNAL;
+				goto end;
+			} else if (type == AVC_BRIDGECO_PLUG_TYPE_SYNC) {
+				/* Often word clock. */
+				*src = SND_BEBOB_CLOCK_TYPE_EXTERNAL;
+				goto end;
+			} else if (type == AVC_BRIDGECO_PLUG_TYPE_ADDITION) {
+				/*
+				 * Not standard.
+				 * Mostly, additional internal clock.
+				 */
+				*src = SND_BEBOB_CLOCK_TYPE_INTERNAL;
+				goto end;
+			}
+		}
+	}
+
+	/* Not supported. */
+	err = -EIO;
+end:
+	return err;
+}
+
+static int map_data_channels(struct snd_bebob *bebob, struct amdtp_stream *s)
+{
+	unsigned int sec, sections, ch, channels;
+	unsigned int pcm, midi, location;
+	unsigned int stm_pos, sec_loc, pos;
+	u8 *buf, addr[AVC_BRIDGECO_ADDR_BYTES], type;
+	enum avc_bridgeco_plug_dir dir;
+	int err;
+
+	/*
+	 * The length of return value of this command cannot be expected. Here
+	 * use the maximum length of FCP.
+	 */
+	buf = kzalloc(256, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	if (s == &bebob->tx_stream)
+		dir = AVC_BRIDGECO_PLUG_DIR_OUT;
+	else
+		dir = AVC_BRIDGECO_PLUG_DIR_IN;
+
+	avc_bridgeco_fill_unit_addr(addr, dir, AVC_BRIDGECO_PLUG_UNIT_ISOC, 0);
+	err = avc_bridgeco_get_plug_ch_pos(bebob->unit, addr, buf, 256);
+	if (err < 0) {
+		dev_err(&bebob->unit->device,
+			"fail to get channel position for isoc %s plug 0: %d\n",
+			(dir == AVC_BRIDGECO_PLUG_DIR_IN) ? "in" : "out",
+			err);
+		goto end;
+	}
+	pos = 0;
+
+	/* positions in I/O buffer */
+	pcm = 0;
+	midi = 0;
+
+	/* the number of sections in AMDTP packet */
+	sections = buf[pos++];
+
+	for (sec = 0; sec < sections; sec++) {
+		/* type of this section */
+		avc_bridgeco_fill_unit_addr(addr, dir,
+					    AVC_BRIDGECO_PLUG_UNIT_ISOC, 0);
+		err = avc_bridgeco_get_plug_section_type(bebob->unit, addr,
+							 sec, &type);
+		if (err < 0) {
+			dev_err(&bebob->unit->device,
+			"fail to get section type for isoc %s plug 0: %d\n",
+				(dir == AVC_BRIDGECO_PLUG_DIR_IN) ? "in" :
+								    "out",
+				err);
+			goto end;
+		}
+		/* NoType */
+		if (type == 0xff) {
+			err = -ENOSYS;
+			goto end;
+		}
+
+		/* the number of channels in this section */
+		channels = buf[pos++];
+
+		for (ch = 0; ch < channels; ch++) {
+			/* position of this channel in AMDTP packet */
+			stm_pos = buf[pos++] - 1;
+			/* location of this channel in this section */
+			sec_loc = buf[pos++] - 1;
+
+			/*
+			 * Basically the number of location is within the
+			 * number of channels in this section. But some models
+			 * of M-Audio don't follow this. Its location for MIDI
+			 * is the position of MIDI channels in AMDTP packet.
+			 */
+			if (sec_loc >= channels)
+				sec_loc = ch;
+
+			switch (type) {
+			/* for MIDI conformant data channel */
+			case 0x0a:
+				/* AMDTP_MAX_CHANNELS_FOR_MIDI is 1. */
+				if ((midi > 0) && (stm_pos != midi)) {
+					err = -ENOSYS;
+					goto end;
+				}
+				amdtp_am824_set_midi_position(s, stm_pos);
+				midi = stm_pos;
+				break;
+			/* for PCM data channel */
+			case 0x01:	/* Headphone */
+			case 0x02:	/* Microphone */
+			case 0x03:	/* Line */
+			case 0x04:	/* SPDIF */
+			case 0x05:	/* ADAT */
+			case 0x06:	/* TDIF */
+			case 0x07:	/* MADI */
+			/* for undefined/changeable signal  */
+			case 0x08:	/* Analog */
+			case 0x09:	/* Digital */
+			default:
+				location = pcm + sec_loc;
+				if (location >= AM824_MAX_CHANNELS_FOR_PCM) {
+					err = -ENOSYS;
+					goto end;
+				}
+				amdtp_am824_set_pcm_position(s, location,
+							     stm_pos);
+				break;
+			}
+		}
+
+		if (type != 0x0a)
+			pcm += channels;
+		else
+			midi += channels;
+	}
+end:
+	kfree(buf);
+	return err;
+}
+
+static int
+check_connection_used_by_others(struct snd_bebob *bebob, struct amdtp_stream *s)
+{
+	struct cmp_connection *conn;
+	bool used;
+	int err;
+
+	if (s == &bebob->tx_stream)
+		conn = &bebob->out_conn;
+	else
+		conn = &bebob->in_conn;
+
+	err = cmp_connection_check_used(conn, &used);
+	if ((err >= 0) && used && !amdtp_stream_running(s)) {
+		dev_err(&bebob->unit->device,
+			"Connection established by others: %cPCR[%d]\n",
+			(conn->direction == CMP_OUTPUT) ? 'o' : 'i',
+			conn->pcr_index);
+		err = -EBUSY;
+	}
+
+	return err;
+}
+
+static void break_both_connections(struct snd_bebob *bebob)
+{
+	cmp_connection_break(&bebob->in_conn);
+	cmp_connection_break(&bebob->out_conn);
+}
+
+static int start_stream(struct snd_bebob *bebob, struct amdtp_stream *stream)
+{
+	struct cmp_connection *conn;
+	int err = 0;
+
+	if (stream == &bebob->rx_stream)
+		conn = &bebob->in_conn;
+	else
+		conn = &bebob->out_conn;
+
+	// channel mapping.
+	if (bebob->maudio_special_quirk == NULL) {
+		err = map_data_channels(bebob, stream);
+		if (err < 0)
+			return err;
+	}
+
+	err = cmp_connection_establish(conn);
+	if (err < 0)
+		return err;
+
+	return amdtp_domain_add_stream(&bebob->domain, stream,
+				       conn->resources.channel, conn->speed);
+}
+
+static int init_stream(struct snd_bebob *bebob, struct amdtp_stream *stream)
+{
+	unsigned int flags = CIP_BLOCKING;
+	enum amdtp_stream_direction dir_stream;
+	struct cmp_connection *conn;
+	enum cmp_direction dir_conn;
+	int err;
+
+	if (stream == &bebob->tx_stream) {
+		dir_stream = AMDTP_IN_STREAM;
+		conn = &bebob->out_conn;
+		dir_conn = CMP_OUTPUT;
+	} else {
+		dir_stream = AMDTP_OUT_STREAM;
+		conn = &bebob->in_conn;
+		dir_conn = CMP_INPUT;
+	}
+
+	if (stream == &bebob->tx_stream) {
+		if (bebob->quirks & SND_BEBOB_QUIRK_WRONG_DBC)
+			flags |= CIP_EMPTY_HAS_WRONG_DBC;
+	}
+
+	err = cmp_connection_init(conn, bebob->unit, dir_conn, 0);
+	if (err < 0)
+		return err;
+
+	err = amdtp_am824_init(stream, bebob->unit, dir_stream, flags);
+	if (err < 0) {
+		cmp_connection_destroy(conn);
+		return err;
+	}
+
+	return 0;
+}
+
+static void destroy_stream(struct snd_bebob *bebob, struct amdtp_stream *stream)
+{
+	amdtp_stream_destroy(stream);
+
+	if (stream == &bebob->tx_stream)
+		cmp_connection_destroy(&bebob->out_conn);
+	else
+		cmp_connection_destroy(&bebob->in_conn);
+}
+
+int snd_bebob_stream_init_duplex(struct snd_bebob *bebob)
+{
+	int err;
+
+	err = init_stream(bebob, &bebob->tx_stream);
+	if (err < 0)
+		return err;
+
+	err = init_stream(bebob, &bebob->rx_stream);
+	if (err < 0) {
+		destroy_stream(bebob, &bebob->tx_stream);
+		return err;
+	}
+
+	err = amdtp_domain_init(&bebob->domain);
+	if (err < 0) {
+		destroy_stream(bebob, &bebob->tx_stream);
+		destroy_stream(bebob, &bebob->rx_stream);
+	}
+
+	return err;
+}
+
+static int keep_resources(struct snd_bebob *bebob, struct amdtp_stream *stream,
+			  unsigned int rate, unsigned int index)
+{
+	unsigned int pcm_channels;
+	unsigned int midi_ports;
+	struct cmp_connection *conn;
+	int err;
+
+	if (stream == &bebob->tx_stream) {
+		pcm_channels = bebob->tx_stream_formations[index].pcm;
+		midi_ports = bebob->midi_input_ports;
+		conn = &bebob->out_conn;
+	} else {
+		pcm_channels = bebob->rx_stream_formations[index].pcm;
+		midi_ports = bebob->midi_output_ports;
+		conn = &bebob->in_conn;
+	}
+
+	err = amdtp_am824_set_parameters(stream, rate, pcm_channels, midi_ports, false);
+	if (err < 0)
+		return err;
+
+	return cmp_connection_reserve(conn, amdtp_stream_get_max_payload(stream));
+}
+
+int snd_bebob_stream_reserve_duplex(struct snd_bebob *bebob, unsigned int rate,
+				    unsigned int frames_per_period,
+				    unsigned int frames_per_buffer)
+{
+	unsigned int curr_rate;
+	int err;
+
+	// Considering JACK/FFADO streaming:
+	// TODO: This can be removed hwdep functionality becomes popular.
+	err = check_connection_used_by_others(bebob, &bebob->rx_stream);
+	if (err < 0)
+		return err;
+
+	err = bebob->spec->rate->get(bebob, &curr_rate);
+	if (err < 0)
+		return err;
+	if (rate == 0)
+		rate = curr_rate;
+	if (curr_rate != rate) {
+		amdtp_domain_stop(&bebob->domain);
+		break_both_connections(bebob);
+
+		cmp_connection_release(&bebob->out_conn);
+		cmp_connection_release(&bebob->in_conn);
+	}
+
+	if (bebob->substreams_counter == 0 || curr_rate != rate) {
+		unsigned int index;
+
+		// NOTE:
+		// If establishing connections at first, Yamaha GO46
+		// (and maybe Terratec X24) don't generate sound.
+		//
+		// For firmware customized by M-Audio, refer to next NOTE.
+		err = bebob->spec->rate->set(bebob, rate);
+		if (err < 0) {
+			dev_err(&bebob->unit->device,
+				"fail to set sampling rate: %d\n",
+				err);
+			return err;
+		}
+
+		err = get_formation_index(rate, &index);
+		if (err < 0)
+			return err;
+
+		err = keep_resources(bebob, &bebob->tx_stream, rate, index);
+		if (err < 0)
+			return err;
+
+		err = keep_resources(bebob, &bebob->rx_stream, rate, index);
+		if (err < 0) {
+			cmp_connection_release(&bebob->out_conn);
+			return err;
+		}
+
+		err = amdtp_domain_set_events_per_period(&bebob->domain,
+					frames_per_period, frames_per_buffer);
+		if (err < 0) {
+			cmp_connection_release(&bebob->out_conn);
+			cmp_connection_release(&bebob->in_conn);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+int snd_bebob_stream_start_duplex(struct snd_bebob *bebob)
+{
+	int err;
+
+	// Need no substreams.
+	if (bebob->substreams_counter == 0)
+		return -EIO;
+
+	// packet queueing error or detecting discontinuity
+	if (amdtp_streaming_error(&bebob->rx_stream) ||
+	    amdtp_streaming_error(&bebob->tx_stream)) {
+		amdtp_domain_stop(&bebob->domain);
+		break_both_connections(bebob);
+	}
+
+	if (!amdtp_stream_running(&bebob->rx_stream)) {
+		enum snd_bebob_clock_type src;
+		unsigned int curr_rate;
+		unsigned int tx_init_skip_cycles;
+
+		if (bebob->maudio_special_quirk) {
+			err = bebob->spec->rate->get(bebob, &curr_rate);
+			if (err < 0)
+				return err;
+		}
+
+		err = snd_bebob_stream_get_clock_src(bebob, &src);
+		if (err < 0)
+			return err;
+
+		err = start_stream(bebob, &bebob->rx_stream);
+		if (err < 0)
+			goto error;
+
+		err = start_stream(bebob, &bebob->tx_stream);
+		if (err < 0)
+			goto error;
+
+		if (!(bebob->quirks & SND_BEBOB_QUIRK_INITIAL_DISCONTINUOUS_DBC))
+			tx_init_skip_cycles = 0;
+		else
+			tx_init_skip_cycles = 16000;
+
+		// MEMO: Some devices start packet transmission long enough after establishment of
+		// CMP connection. In the early stage of packet streaming, any device transfers
+		// NODATA packets. After several hundred cycles, it begins to multiplex event into
+		// the packet with adequate value of syt field in CIP header. Some devices are
+		// strictly to generate any discontinuity in the sequence of tx packet when they
+		// receives inadequate sequence of value in syt field of CIP header. In the case,
+		// the request to break CMP connection is often corrupted, then any transaction
+		// results in unrecoverable error, sometimes generate bus-reset.
+		err = amdtp_domain_start(&bebob->domain, tx_init_skip_cycles, true, false);
+		if (err < 0)
+			goto error;
+
+		// NOTE:
+		// The firmware customized by M-Audio uses these commands to
+		// start transmitting stream. This is not usual way.
+		if (bebob->maudio_special_quirk) {
+			err = bebob->spec->rate->set(bebob, curr_rate);
+			if (err < 0) {
+				dev_err(&bebob->unit->device,
+					"fail to ensure sampling rate: %d\n",
+					err);
+				goto error;
+			}
+		}
+
+		// Some devices postpone start of transmission mostly for 1 sec after receives
+		// packets firstly.
+		if (!amdtp_domain_wait_ready(&bebob->domain, READY_TIMEOUT_MS)) {
+			err = -ETIMEDOUT;
+			goto error;
+		}
+	}
+
+	return 0;
+error:
+	amdtp_domain_stop(&bebob->domain);
+	break_both_connections(bebob);
+	return err;
+}
+
+void snd_bebob_stream_stop_duplex(struct snd_bebob *bebob)
+{
+	if (bebob->substreams_counter == 0) {
+		amdtp_domain_stop(&bebob->domain);
+		break_both_connections(bebob);
+
+		cmp_connection_release(&bebob->out_conn);
+		cmp_connection_release(&bebob->in_conn);
+	}
+}
+
+/*
+ * This function should be called before starting streams or after stopping
+ * streams.
+ */
+void snd_bebob_stream_destroy_duplex(struct snd_bebob *bebob)
+{
+	amdtp_domain_destroy(&bebob->domain);
+
+	destroy_stream(bebob, &bebob->tx_stream);
+	destroy_stream(bebob, &bebob->rx_stream);
+}
+
+/*
+ * See: Table 50: Extended Stream Format Info Format Hierarchy Level 2’
+ * in Additional AVC commands (Nov 2003, BridgeCo)
+ * Also 'Clause 12 AM824 sequence adaption layers' in IEC 61883-6:2005
+ */
+static int
+parse_stream_formation(u8 *buf, unsigned int len,
+		       struct snd_bebob_stream_formation *formation)
+{
+	unsigned int i, e, channels, format;
+
+	/*
+	 * this module can support a hierarchy combination that:
+	 *  Root:	Audio and Music (0x90)
+	 *  Level 1:	AM824 Compound  (0x40)
+	 */
+	if ((buf[0] != 0x90) || (buf[1] != 0x40))
+		return -ENOSYS;
+
+	/* check sampling rate */
+	for (i = 0; i < ARRAY_SIZE(bridgeco_freq_table); i++) {
+		if (buf[2] == bridgeco_freq_table[i])
+			break;
+	}
+	if (i == ARRAY_SIZE(bridgeco_freq_table))
+		return -ENOSYS;
+
+	/* Avoid double count by different entries for the same rate. */
+	memset(&formation[i], 0, sizeof(struct snd_bebob_stream_formation));
+
+	for (e = 0; e < buf[4]; e++) {
+		channels = buf[5 + e * 2];
+		format = buf[6 + e * 2];
+
+		switch (format) {
+		/* IEC 60958 Conformant, currently handled as MBLA */
+		case 0x00:
+		/* Multi bit linear audio */
+		case 0x06:	/* Raw */
+			formation[i].pcm += channels;
+			break;
+		/* MIDI Conformant */
+		case 0x0d:
+			formation[i].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 */
+		/* Synchronization Stream (Stereo Raw audio) */
+		case 0x40:
+		/* Don't care */
+		case 0xff:
+		default:
+			return -ENOSYS;	/* not supported */
+		}
+	}
+
+	if (formation[i].pcm  > AM824_MAX_CHANNELS_FOR_PCM ||
+	    formation[i].midi > AM824_MAX_CHANNELS_FOR_MIDI)
+		return -ENOSYS;
+
+	return 0;
+}
+
+static int fill_stream_formations(struct snd_bebob *bebob, u8 addr[AVC_BRIDGECO_ADDR_BYTES],
+				  enum avc_bridgeco_plug_dir plug_dir, unsigned int plug_id,
+				  struct snd_bebob_stream_formation *formations)
+{
+	enum avc_bridgeco_plug_type plug_type;
+	u8 *buf;
+	unsigned int len, eid;
+	int err;
+
+	avc_bridgeco_fill_unit_addr(addr, plug_dir, AVC_BRIDGECO_PLUG_UNIT_ISOC, plug_id);
+
+	err = avc_bridgeco_get_plug_type(bebob->unit, addr, &plug_type);
+	if (err < 0) {
+		dev_err(&bebob->unit->device,
+			"Fail to get type for isoc %d plug 0: %d\n", plug_dir, err);
+		return err;
+	} else if (plug_type != AVC_BRIDGECO_PLUG_TYPE_ISOC)
+		return -ENXIO;
+
+	buf = kmalloc(FORMAT_MAXIMUM_LENGTH, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	for (eid = 0; eid < SND_BEBOB_STRM_FMT_ENTRIES; ++eid) {
+		avc_bridgeco_fill_unit_addr(addr, plug_dir, AVC_BRIDGECO_PLUG_UNIT_ISOC, plug_id);
+
+		len = FORMAT_MAXIMUM_LENGTH;
+		err = avc_bridgeco_get_plug_strm_fmt(bebob->unit, addr, buf, &len, eid);
+		// No entries remained.
+		if (err == -EINVAL && eid > 0) {
+			err = 0;
+			break;
+		} else if (err < 0) {
+			dev_err(&bebob->unit->device,
+				"fail to get stream format %d for isoc %d plug %d:%d\n",
+				eid, plug_dir, plug_id, err);
+			break;
+		}
+
+		err = parse_stream_formation(buf, len, formations);
+		if (err < 0)
+			break;
+	}
+
+	kfree(buf);
+	return err;
+}
+
+static int detect_midi_ports(struct snd_bebob *bebob,
+			     const struct snd_bebob_stream_formation *formats,
+			     u8 addr[AVC_BRIDGECO_ADDR_BYTES], enum avc_bridgeco_plug_dir plug_dir,
+			     unsigned int plug_count, unsigned int *midi_ports)
+{
+	int i;
+	int err = 0;
+
+	*midi_ports = 0;
+
+	/// Detect the number of available MIDI ports when packet has MIDI conformant data channel.
+	for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; ++i) {
+		if (formats[i].midi > 0)
+			break;
+	}
+	if (i >= SND_BEBOB_STRM_FMT_ENTRIES)
+		return 0;
+
+	for (i = 0; i < plug_count; ++i) {
+		enum avc_bridgeco_plug_type plug_type;
+		unsigned int ch_count;
+
+		avc_bridgeco_fill_unit_addr(addr, plug_dir, AVC_BRIDGECO_PLUG_UNIT_EXT, i);
+
+		err = avc_bridgeco_get_plug_type(bebob->unit, addr, &plug_type);
+		if (err < 0) {
+			dev_err(&bebob->unit->device,
+				"fail to get type for external %d plug %d: %d\n",
+				plug_dir, i, err);
+			break;
+		} else if (plug_type != AVC_BRIDGECO_PLUG_TYPE_MIDI) {
+			continue;
+		}
+
+		err = avc_bridgeco_get_plug_ch_count(bebob->unit, addr, &ch_count);
+		if (err < 0)
+			break;
+		// Yamaha GO44, GO46, Terratec Phase 24, Phase x24 reports 0 for the number of
+		// channels in external output plug 3 (MIDI type) even if it has a pair of physical
+		// MIDI jacks. As a workaround, assume it as one.
+		if (ch_count == 0)
+			ch_count = 1;
+		*midi_ports += ch_count;
+	}
+
+	return err;
+}
+
+static int
+seek_msu_sync_input_plug(struct snd_bebob *bebob)
+{
+	u8 plugs[AVC_PLUG_INFO_BUF_BYTES], addr[AVC_BRIDGECO_ADDR_BYTES];
+	unsigned int i;
+	enum avc_bridgeco_plug_type type;
+	int err;
+
+	/* Get the number of Music Sub Unit for both direction. */
+	err = avc_general_get_plug_info(bebob->unit, 0x0c, 0x00, 0x00, plugs);
+	if (err < 0) {
+		dev_err(&bebob->unit->device,
+			"fail to get info for MSU in/out plugs: %d\n",
+			err);
+		goto end;
+	}
+
+	/* seek destination plugs for 'MSU sync input' */
+	bebob->sync_input_plug = -1;
+	for (i = 0; i < plugs[0]; i++) {
+		avc_bridgeco_fill_msu_addr(addr, AVC_BRIDGECO_PLUG_DIR_IN, i);
+		err = avc_bridgeco_get_plug_type(bebob->unit, addr, &type);
+		if (err < 0) {
+			dev_err(&bebob->unit->device,
+				"fail to get type for MSU in plug %d: %d\n",
+				i, err);
+			goto end;
+		}
+
+		if (type == AVC_BRIDGECO_PLUG_TYPE_SYNC) {
+			bebob->sync_input_plug = i;
+			break;
+		}
+	}
+end:
+	return err;
+}
+
+int snd_bebob_stream_discover(struct snd_bebob *bebob)
+{
+	const struct snd_bebob_clock_spec *clk_spec = bebob->spec->clock;
+	u8 plugs[AVC_PLUG_INFO_BUF_BYTES], addr[AVC_BRIDGECO_ADDR_BYTES];
+	int err;
+
+	/* the number of plugs for isoc in/out, ext in/out  */
+	err = avc_general_get_plug_info(bebob->unit, 0x1f, 0x07, 0x00, plugs);
+	if (err < 0) {
+		dev_err(&bebob->unit->device,
+		"fail to get info for isoc/external in/out plugs: %d\n",
+			err);
+		goto end;
+	}
+
+	/*
+	 * This module supports at least one isoc input plug and one isoc
+	 * output plug.
+	 */
+	if ((plugs[0] == 0) || (plugs[1] == 0)) {
+		err = -ENOSYS;
+		goto end;
+	}
+
+	err = fill_stream_formations(bebob, addr, AVC_BRIDGECO_PLUG_DIR_IN, 0,
+				     bebob->rx_stream_formations);
+	if (err < 0)
+		goto end;
+
+	err = fill_stream_formations(bebob, addr, AVC_BRIDGECO_PLUG_DIR_OUT, 0,
+				     bebob->tx_stream_formations);
+	if (err < 0)
+		goto end;
+
+	err = detect_midi_ports(bebob, bebob->tx_stream_formations, addr, AVC_BRIDGECO_PLUG_DIR_IN,
+				plugs[2], &bebob->midi_input_ports);
+	if (err < 0)
+		goto end;
+
+	err = detect_midi_ports(bebob, bebob->rx_stream_formations, addr, AVC_BRIDGECO_PLUG_DIR_OUT,
+				plugs[3], &bebob->midi_output_ports);
+	if (err < 0)
+		goto end;
+
+	/* for check source of clock later */
+	if (!clk_spec)
+		err = seek_msu_sync_input_plug(bebob);
+end:
+	return err;
+}
+
+void snd_bebob_stream_lock_changed(struct snd_bebob *bebob)
+{
+	bebob->dev_lock_changed = true;
+	wake_up(&bebob->hwdep_wait);
+}
+
+int snd_bebob_stream_lock_try(struct snd_bebob *bebob)
+{
+	int err;
+
+	spin_lock_irq(&bebob->lock);
+
+	/* user land lock this */
+	if (bebob->dev_lock_count < 0) {
+		err = -EBUSY;
+		goto end;
+	}
+
+	/* this is the first time */
+	if (bebob->dev_lock_count++ == 0)
+		snd_bebob_stream_lock_changed(bebob);
+	err = 0;
+end:
+	spin_unlock_irq(&bebob->lock);
+	return err;
+}
+
+void snd_bebob_stream_lock_release(struct snd_bebob *bebob)
+{
+	spin_lock_irq(&bebob->lock);
+
+	if (WARN_ON(bebob->dev_lock_count <= 0))
+		goto end;
+	if (--bebob->dev_lock_count == 0)
+		snd_bebob_stream_lock_changed(bebob);
+end:
+	spin_unlock_irq(&bebob->lock);
+}