v4.19.13 snapshot.
diff --git a/sound/firewire/fireface/Makefile b/sound/firewire/fireface/Makefile
new file mode 100644
index 0000000..8f80728
--- /dev/null
+++ b/sound/firewire/fireface/Makefile
@@ -0,0 +1,3 @@
+snd-fireface-objs := ff.o ff-transaction.o ff-midi.o ff-proc.o amdtp-ff.o \
+		     ff-stream.o ff-pcm.o ff-hwdep.o ff-protocol-ff400.o
+obj-$(CONFIG_SND_FIREFACE) += snd-fireface.o
diff --git a/sound/firewire/fireface/amdtp-ff.c b/sound/firewire/fireface/amdtp-ff.c
new file mode 100644
index 0000000..77c7598
--- /dev/null
+++ b/sound/firewire/fireface/amdtp-ff.c
@@ -0,0 +1,155 @@
+/*
+ * amdtp-ff.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <sound/pcm.h>
+#include "ff.h"
+
+struct amdtp_ff {
+	unsigned int pcm_channels;
+};
+
+int amdtp_ff_set_parameters(struct amdtp_stream *s, unsigned int rate,
+			    unsigned int pcm_channels)
+{
+	struct amdtp_ff *p = s->protocol;
+	unsigned int data_channels;
+
+	if (amdtp_stream_running(s))
+		return -EBUSY;
+
+	p->pcm_channels = pcm_channels;
+	data_channels = pcm_channels;
+
+	return amdtp_stream_set_parameters(s, rate, data_channels);
+}
+
+static void write_pcm_s32(struct amdtp_stream *s,
+			  struct snd_pcm_substream *pcm,
+			  __le32 *buffer, unsigned int frames)
+{
+	struct amdtp_ff *p = s->protocol;
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, i, c;
+	const u32 *src;
+
+	channels = p->pcm_channels;
+	src = (void *)runtime->dma_area +
+			frames_to_bytes(runtime, s->pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			buffer[c] = cpu_to_le32(*src);
+			src++;
+		}
+		buffer += s->data_block_quadlets;
+		if (--remaining_frames == 0)
+			src = (void *)runtime->dma_area;
+	}
+}
+
+static void read_pcm_s32(struct amdtp_stream *s,
+			 struct snd_pcm_substream *pcm,
+			 __le32 *buffer, unsigned int frames)
+{
+	struct amdtp_ff *p = s->protocol;
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, i, c;
+	u32 *dst;
+
+	channels = p->pcm_channels;
+	dst  = (void *)runtime->dma_area +
+			frames_to_bytes(runtime, s->pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*dst = le32_to_cpu(buffer[c]) & 0xffffff00;
+			dst++;
+		}
+		buffer += s->data_block_quadlets;
+		if (--remaining_frames == 0)
+			dst = (void *)runtime->dma_area;
+	}
+}
+
+static void write_pcm_silence(struct amdtp_stream *s,
+			      __le32 *buffer, unsigned int frames)
+{
+	struct amdtp_ff *p = s->protocol;
+	unsigned int i, c, channels = p->pcm_channels;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c)
+			buffer[c] = cpu_to_le32(0x00000000);
+		buffer += s->data_block_quadlets;
+	}
+}
+
+int amdtp_ff_add_pcm_hw_constraints(struct amdtp_stream *s,
+				    struct snd_pcm_runtime *runtime)
+{
+	int err;
+
+	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
+	if (err < 0)
+		return err;
+
+	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
+}
+
+static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
+					   __be32 *buffer,
+					   unsigned int data_blocks,
+					   unsigned int *syt)
+{
+	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
+	unsigned int pcm_frames;
+
+	if (pcm) {
+		write_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
+		pcm_frames = data_blocks;
+	} else {
+		write_pcm_silence(s, (__le32 *)buffer, data_blocks);
+		pcm_frames = 0;
+	}
+
+	return pcm_frames;
+}
+
+static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
+					   __be32 *buffer,
+					   unsigned int data_blocks,
+					   unsigned int *syt)
+{
+	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
+	unsigned int pcm_frames;
+
+	if (pcm) {
+		read_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
+		pcm_frames = data_blocks;
+	} else {
+		pcm_frames = 0;
+	}
+
+	return pcm_frames;
+}
+
+int amdtp_ff_init(struct amdtp_stream *s, struct fw_unit *unit,
+		  enum amdtp_stream_direction dir)
+{
+	amdtp_stream_process_data_blocks_t process_data_blocks;
+
+	if (dir == AMDTP_IN_STREAM)
+		process_data_blocks = process_tx_data_blocks;
+	else
+		process_data_blocks = process_rx_data_blocks;
+
+	return amdtp_stream_init(s, unit, dir, CIP_NO_HEADER, 0,
+				 process_data_blocks, sizeof(struct amdtp_ff));
+}
diff --git a/sound/firewire/fireface/ff-hwdep.c b/sound/firewire/fireface/ff-hwdep.c
new file mode 100644
index 0000000..336c007
--- /dev/null
+++ b/sound/firewire/fireface/ff-hwdep.c
@@ -0,0 +1,191 @@
+/*
+ * ff-hwdep.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+/*
+ * This codes give three functionality.
+ *
+ * 1.get firewire node information
+ * 2.get notification about starting/stopping stream
+ * 3.lock/unlock stream
+ */
+
+#include "ff.h"
+
+static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf,  long count,
+		       loff_t *offset)
+{
+	struct snd_ff *ff = hwdep->private_data;
+	DEFINE_WAIT(wait);
+	union snd_firewire_event event;
+
+	spin_lock_irq(&ff->lock);
+
+	while (!ff->dev_lock_changed) {
+		prepare_to_wait(&ff->hwdep_wait, &wait, TASK_INTERRUPTIBLE);
+		spin_unlock_irq(&ff->lock);
+		schedule();
+		finish_wait(&ff->hwdep_wait, &wait);
+		if (signal_pending(current))
+			return -ERESTARTSYS;
+		spin_lock_irq(&ff->lock);
+	}
+
+	memset(&event, 0, sizeof(event));
+	if (ff->dev_lock_changed) {
+		event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
+		event.lock_status.status = (ff->dev_lock_count > 0);
+		ff->dev_lock_changed = false;
+
+		count = min_t(long, count, sizeof(event.lock_status));
+	}
+
+	spin_unlock_irq(&ff->lock);
+
+	if (copy_to_user(buf, &event, count))
+		return -EFAULT;
+
+	return count;
+}
+
+static __poll_t hwdep_poll(struct snd_hwdep *hwdep, struct file *file,
+			       poll_table *wait)
+{
+	struct snd_ff *ff = hwdep->private_data;
+	__poll_t events;
+
+	poll_wait(file, &ff->hwdep_wait, wait);
+
+	spin_lock_irq(&ff->lock);
+	if (ff->dev_lock_changed)
+		events = EPOLLIN | EPOLLRDNORM;
+	else
+		events = 0;
+	spin_unlock_irq(&ff->lock);
+
+	return events;
+}
+
+static int hwdep_get_info(struct snd_ff *ff, void __user *arg)
+{
+	struct fw_device *dev = fw_parent_device(ff->unit);
+	struct snd_firewire_get_info info;
+
+	memset(&info, 0, sizeof(info));
+	info.type = SNDRV_FIREWIRE_TYPE_FIREFACE;
+	info.card = dev->card->index;
+	*(__be32 *)&info.guid[0] = cpu_to_be32(dev->config_rom[3]);
+	*(__be32 *)&info.guid[4] = cpu_to_be32(dev->config_rom[4]);
+	strlcpy(info.device_name, dev_name(&dev->device),
+		sizeof(info.device_name));
+
+	if (copy_to_user(arg, &info, sizeof(info)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int hwdep_lock(struct snd_ff *ff)
+{
+	int err;
+
+	spin_lock_irq(&ff->lock);
+
+	if (ff->dev_lock_count == 0) {
+		ff->dev_lock_count = -1;
+		err = 0;
+	} else {
+		err = -EBUSY;
+	}
+
+	spin_unlock_irq(&ff->lock);
+
+	return err;
+}
+
+static int hwdep_unlock(struct snd_ff *ff)
+{
+	int err;
+
+	spin_lock_irq(&ff->lock);
+
+	if (ff->dev_lock_count == -1) {
+		ff->dev_lock_count = 0;
+		err = 0;
+	} else {
+		err = -EBADFD;
+	}
+
+	spin_unlock_irq(&ff->lock);
+
+	return err;
+}
+
+static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)
+{
+	struct snd_ff *ff = hwdep->private_data;
+
+	spin_lock_irq(&ff->lock);
+	if (ff->dev_lock_count == -1)
+		ff->dev_lock_count = 0;
+	spin_unlock_irq(&ff->lock);
+
+	return 0;
+}
+
+static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
+		       unsigned int cmd, unsigned long arg)
+{
+	struct snd_ff *ff = hwdep->private_data;
+
+	switch (cmd) {
+	case SNDRV_FIREWIRE_IOCTL_GET_INFO:
+		return hwdep_get_info(ff, (void __user *)arg);
+	case SNDRV_FIREWIRE_IOCTL_LOCK:
+		return hwdep_lock(ff);
+	case SNDRV_FIREWIRE_IOCTL_UNLOCK:
+		return hwdep_unlock(ff);
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+static int hwdep_compat_ioctl(struct snd_hwdep *hwdep, struct file *file,
+			      unsigned int cmd, unsigned long arg)
+{
+	return hwdep_ioctl(hwdep, file, cmd,
+			   (unsigned long)compat_ptr(arg));
+}
+#else
+#define hwdep_compat_ioctl NULL
+#endif
+
+int snd_ff_create_hwdep_devices(struct snd_ff *ff)
+{
+	static const struct snd_hwdep_ops hwdep_ops = {
+		.read		= hwdep_read,
+		.release	= hwdep_release,
+		.poll		= hwdep_poll,
+		.ioctl		= hwdep_ioctl,
+		.ioctl_compat	= hwdep_compat_ioctl,
+	};
+	struct snd_hwdep *hwdep;
+	int err;
+
+	err = snd_hwdep_new(ff->card, ff->card->driver, 0, &hwdep);
+	if (err < 0)
+		return err;
+
+	strcpy(hwdep->name, ff->card->driver);
+	hwdep->iface = SNDRV_HWDEP_IFACE_FW_FIREFACE;
+	hwdep->ops = hwdep_ops;
+	hwdep->private_data = ff;
+	hwdep->exclusive = true;
+
+	return 0;
+}
diff --git a/sound/firewire/fireface/ff-midi.c b/sound/firewire/fireface/ff-midi.c
new file mode 100644
index 0000000..6a49611
--- /dev/null
+++ b/sound/firewire/fireface/ff-midi.c
@@ -0,0 +1,129 @@
+/*
+ * ff-midi.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+static int midi_capture_open(struct snd_rawmidi_substream *substream)
+{
+	/* Do nothing. */
+	return 0;
+}
+
+static int midi_playback_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ff *ff = substream->rmidi->private_data;
+
+	/* Initialize internal status. */
+	ff->running_status[substream->number] = 0;
+	ff->rx_midi_error[substream->number] = false;
+
+	WRITE_ONCE(ff->rx_midi_substreams[substream->number], substream);
+
+	return 0;
+}
+
+static int midi_capture_close(struct snd_rawmidi_substream *substream)
+{
+	/* Do nothing. */
+	return 0;
+}
+
+static int midi_playback_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ff *ff = substream->rmidi->private_data;
+
+	cancel_work_sync(&ff->rx_midi_work[substream->number]);
+	WRITE_ONCE(ff->rx_midi_substreams[substream->number], NULL);
+
+	return 0;
+}
+
+static void midi_capture_trigger(struct snd_rawmidi_substream *substream,
+				 int up)
+{
+	struct snd_ff *ff = substream->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ff->lock, flags);
+
+	if (up)
+		WRITE_ONCE(ff->tx_midi_substreams[substream->number],
+			   substream);
+	else
+		WRITE_ONCE(ff->tx_midi_substreams[substream->number], NULL);
+
+	spin_unlock_irqrestore(&ff->lock, flags);
+}
+
+static void midi_playback_trigger(struct snd_rawmidi_substream *substream,
+				  int up)
+{
+	struct snd_ff *ff = substream->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ff->lock, flags);
+
+	if (up || !ff->rx_midi_error[substream->number])
+		schedule_work(&ff->rx_midi_work[substream->number]);
+
+	spin_unlock_irqrestore(&ff->lock, flags);
+}
+
+static void set_midi_substream_names(struct snd_rawmidi_str *stream,
+				     const char *const name)
+{
+	struct snd_rawmidi_substream *substream;
+
+	list_for_each_entry(substream, &stream->substreams, list) {
+		snprintf(substream->name, sizeof(substream->name),
+			 "%s MIDI %d", name, substream->number + 1);
+	}
+}
+
+int snd_ff_create_midi_devices(struct snd_ff *ff)
+{
+	static const struct snd_rawmidi_ops midi_capture_ops = {
+		.open		= midi_capture_open,
+		.close		= midi_capture_close,
+		.trigger	= midi_capture_trigger,
+	};
+	static const struct snd_rawmidi_ops midi_playback_ops = {
+		.open		= midi_playback_open,
+		.close		= midi_playback_close,
+		.trigger	= midi_playback_trigger,
+	};
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *stream;
+	int err;
+
+	err = snd_rawmidi_new(ff->card, ff->card->driver, 0,
+			      ff->spec->midi_out_ports, ff->spec->midi_in_ports,
+			      &rmidi);
+	if (err < 0)
+		return err;
+
+	snprintf(rmidi->name, sizeof(rmidi->name),
+		 "%s MIDI", ff->card->shortname);
+	rmidi->private_data = ff;
+
+	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+			    &midi_capture_ops);
+	stream = &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT];
+	set_midi_substream_names(stream, ff->card->shortname);
+
+	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+			    &midi_playback_ops);
+	stream = &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT];
+	set_midi_substream_names(stream, ff->card->shortname);
+
+	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	return 0;
+}
diff --git a/sound/firewire/fireface/ff-pcm.c b/sound/firewire/fireface/ff-pcm.c
new file mode 100644
index 0000000..bf47f9e
--- /dev/null
+++ b/sound/firewire/fireface/ff-pcm.c
@@ -0,0 +1,401 @@
+/*
+ * ff-pcm.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+static inline unsigned int get_multiplier_mode_with_index(unsigned int index)
+{
+	return ((int)index - 1) / 2;
+}
+
+static int hw_rule_rate(struct snd_pcm_hw_params *params,
+			struct snd_pcm_hw_rule *rule)
+{
+	const unsigned int *pcm_channels = 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, mode;
+
+	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+		mode = get_multiplier_mode_with_index(i);
+		if (!snd_interval_test(c, pcm_channels[mode]))
+			continue;
+
+		t.min = min(t.min, amdtp_rate_table[i]);
+		t.max = max(t.max, amdtp_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)
+{
+	const unsigned int *pcm_channels = 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, mode;
+
+	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+		mode = get_multiplier_mode_with_index(i);
+		if (!snd_interval_test(r, amdtp_rate_table[i]))
+			continue;
+
+		t.min = min(t.min, pcm_channels[mode]);
+		t.max = max(t.max, pcm_channels[mode]);
+	}
+
+	return snd_interval_refine(c, &t);
+}
+
+static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
+				     const unsigned int *pcm_channels)
+{
+	unsigned int mode;
+	unsigned int rate, channels;
+	int i;
+
+	hw->channels_min = UINT_MAX;
+	hw->channels_max = 0;
+	hw->rate_min = UINT_MAX;
+	hw->rate_max = 0;
+
+	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+		mode = get_multiplier_mode_with_index(i);
+
+		channels = pcm_channels[mode];
+		if (pcm_channels[mode] == 0)
+			continue;
+		hw->channels_min = min(hw->channels_min, channels);
+		hw->channels_max = max(hw->channels_max, channels);
+
+		rate = amdtp_rate_table[i];
+		hw->rates |= snd_pcm_rate_to_rate_bit(rate);
+		hw->rate_min = min(hw->rate_min, rate);
+		hw->rate_max = max(hw->rate_max, rate);
+	}
+}
+
+static int pcm_init_hw_params(struct snd_ff *ff,
+			      struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct amdtp_stream *s;
+	const unsigned int *pcm_channels;
+	int err;
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+		runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
+		s = &ff->tx_stream;
+		pcm_channels = ff->spec->pcm_capture_channels;
+	} else {
+		runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
+		s = &ff->rx_stream;
+		pcm_channels = ff->spec->pcm_playback_channels;
+	}
+
+	limit_channels_and_rates(&runtime->hw, pcm_channels);
+
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+				  hw_rule_channels, (void *)pcm_channels,
+				  SNDRV_PCM_HW_PARAM_RATE, -1);
+	if (err < 0)
+		return err;
+
+	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+				  hw_rule_rate, (void *)pcm_channels,
+				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+	if (err < 0)
+		return err;
+
+	return amdtp_ff_add_pcm_hw_constraints(s, runtime);
+}
+
+static int pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+	unsigned int rate;
+	enum snd_ff_clock_src src;
+	int i, err;
+
+	err = snd_ff_stream_lock_try(ff);
+	if (err < 0)
+		return err;
+
+	err = pcm_init_hw_params(ff, substream);
+	if (err < 0)
+		goto release_lock;
+
+	err = ff->spec->protocol->get_clock(ff, &rate, &src);
+	if (err < 0)
+		goto release_lock;
+
+	if (src != SND_FF_CLOCK_SRC_INTERNAL) {
+		for (i = 0; i < CIP_SFC_COUNT; ++i) {
+			if (amdtp_rate_table[i] == rate)
+				break;
+		}
+		/*
+		 * The unit is configured at sampling frequency which packet
+		 * streaming engine can't support.
+		 */
+		if (i >= CIP_SFC_COUNT) {
+			err = -EIO;
+			goto release_lock;
+		}
+
+		substream->runtime->hw.rate_min = rate;
+		substream->runtime->hw.rate_max = rate;
+	} else {
+		if (amdtp_stream_pcm_running(&ff->rx_stream) ||
+		    amdtp_stream_pcm_running(&ff->tx_stream)) {
+			rate = amdtp_rate_table[ff->rx_stream.sfc];
+			substream->runtime->hw.rate_min = rate;
+			substream->runtime->hw.rate_max = rate;
+		}
+	}
+
+	snd_pcm_set_sync(substream);
+
+	return 0;
+
+release_lock:
+	snd_ff_stream_lock_release(ff);
+	return err;
+}
+
+static int pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	snd_ff_stream_lock_release(ff);
+
+	return 0;
+}
+
+static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *hw_params)
+{
+	struct snd_ff *ff = substream->private_data;
+	int err;
+
+	err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+					       params_buffer_bytes(hw_params));
+	if (err < 0)
+		return err;
+
+	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+		mutex_lock(&ff->mutex);
+		ff->substreams_counter++;
+		mutex_unlock(&ff->mutex);
+	}
+
+	return 0;
+}
+
+static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params *hw_params)
+{
+	struct snd_ff *ff = substream->private_data;
+	int err;
+
+	err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+					       params_buffer_bytes(hw_params));
+	if (err < 0)
+		return err;
+
+	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+		mutex_lock(&ff->mutex);
+		ff->substreams_counter++;
+		mutex_unlock(&ff->mutex);
+	}
+
+	return 0;
+}
+
+static int pcm_capture_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	mutex_lock(&ff->mutex);
+
+	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
+		ff->substreams_counter--;
+
+	snd_ff_stream_stop_duplex(ff);
+
+	mutex_unlock(&ff->mutex);
+
+	return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int pcm_playback_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	mutex_lock(&ff->mutex);
+
+	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
+		ff->substreams_counter--;
+
+	snd_ff_stream_stop_duplex(ff);
+
+	mutex_unlock(&ff->mutex);
+
+	return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int pcm_capture_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+
+	mutex_lock(&ff->mutex);
+
+	err = snd_ff_stream_start_duplex(ff, runtime->rate);
+	if (err >= 0)
+		amdtp_stream_pcm_prepare(&ff->tx_stream);
+
+	mutex_unlock(&ff->mutex);
+
+	return err;
+}
+
+static int pcm_playback_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int err;
+
+	mutex_lock(&ff->mutex);
+
+	err = snd_ff_stream_start_duplex(ff, runtime->rate);
+	if (err >= 0)
+		amdtp_stream_pcm_prepare(&ff->rx_stream);
+
+	mutex_unlock(&ff->mutex);
+
+	return err;
+}
+
+static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		amdtp_stream_pcm_trigger(&ff->tx_stream, substream);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		amdtp_stream_pcm_trigger(&ff->tx_stream, NULL);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		amdtp_stream_pcm_trigger(&ff->rx_stream, substream);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		amdtp_stream_pcm_trigger(&ff->rx_stream, NULL);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
+{
+	struct snd_ff *ff = sbstrm->private_data;
+
+	return amdtp_stream_pcm_pointer(&ff->tx_stream);
+}
+
+static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
+{
+	struct snd_ff *ff = sbstrm->private_data;
+
+	return amdtp_stream_pcm_pointer(&ff->rx_stream);
+}
+
+static int pcm_capture_ack(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	return amdtp_stream_pcm_ack(&ff->tx_stream);
+}
+
+static int pcm_playback_ack(struct snd_pcm_substream *substream)
+{
+	struct snd_ff *ff = substream->private_data;
+
+	return amdtp_stream_pcm_ack(&ff->rx_stream);
+}
+
+int snd_ff_create_pcm_devices(struct snd_ff *ff)
+{
+	static const struct snd_pcm_ops pcm_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,
+		.ack		= pcm_capture_ack,
+		.page		= snd_pcm_lib_get_vmalloc_page,
+	};
+	static const struct snd_pcm_ops pcm_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,
+		.ack		= pcm_playback_ack,
+		.page		= snd_pcm_lib_get_vmalloc_page,
+	};
+	struct snd_pcm *pcm;
+	int err;
+
+	err = snd_pcm_new(ff->card, ff->card->driver, 0, 1, 1, &pcm);
+	if (err < 0)
+		return err;
+
+	pcm->private_data = ff;
+	snprintf(pcm->name, sizeof(pcm->name),
+		 "%s PCM", ff->card->shortname);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_playback_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_capture_ops);
+
+	return 0;
+}
diff --git a/sound/firewire/fireface/ff-proc.c b/sound/firewire/fireface/ff-proc.c
new file mode 100644
index 0000000..40ccbfd
--- /dev/null
+++ b/sound/firewire/fireface/ff-proc.c
@@ -0,0 +1,63 @@
+/*
+ * ff-proc.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "./ff.h"
+
+static void proc_dump_clock_config(struct snd_info_entry *entry,
+				   struct snd_info_buffer *buffer)
+{
+	struct snd_ff *ff = entry->private_data;
+
+	ff->spec->protocol->dump_clock_config(ff, buffer);
+}
+
+static void proc_dump_sync_status(struct snd_info_entry *entry,
+				  struct snd_info_buffer *buffer)
+{
+	struct snd_ff *ff = entry->private_data;
+
+	ff->spec->protocol->dump_sync_status(ff, buffer);
+}
+
+static void add_node(struct snd_ff *ff, struct snd_info_entry *root,
+		     const char *name,
+		     void (*op)(struct snd_info_entry *e,
+				struct snd_info_buffer *b))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(ff->card, name, root);
+	if (entry == NULL)
+		return;
+
+	snd_info_set_text_ops(entry, ff, op);
+	if (snd_info_register(entry) < 0)
+		snd_info_free_entry(entry);
+}
+
+void snd_ff_proc_init(struct snd_ff *ff)
+{
+	struct snd_info_entry *root;
+
+	/*
+	 * All nodes are automatically removed at snd_card_disconnect(),
+	 * by following to link list.
+	 */
+	root = snd_info_create_card_entry(ff->card, "firewire",
+					  ff->card->proc_root);
+	if (root == NULL)
+		return;
+	root->mode = S_IFDIR | 0555;
+	if (snd_info_register(root) < 0) {
+		snd_info_free_entry(root);
+		return;
+	}
+
+	add_node(ff, root, "clock-config", proc_dump_clock_config);
+	add_node(ff, root, "sync-status", proc_dump_sync_status);
+}
diff --git a/sound/firewire/fireface/ff-protocol-ff400.c b/sound/firewire/fireface/ff-protocol-ff400.c
new file mode 100644
index 0000000..654a503
--- /dev/null
+++ b/sound/firewire/fireface/ff-protocol-ff400.c
@@ -0,0 +1,374 @@
+/*
+ * ff-protocol-ff400.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/delay.h>
+#include "ff.h"
+
+#define FF400_STF		0x000080100500ull
+#define FF400_RX_PACKET_FORMAT	0x000080100504ull
+#define FF400_ISOC_COMM_START	0x000080100508ull
+#define FF400_TX_PACKET_FORMAT	0x00008010050cull
+#define FF400_ISOC_COMM_STOP	0x000080100510ull
+#define FF400_SYNC_STATUS	0x0000801c0000ull
+#define FF400_FETCH_PCM_FRAMES	0x0000801c0000ull	/* For block request. */
+#define FF400_CLOCK_CONFIG	0x0000801c0004ull
+
+#define FF400_MIDI_HIGH_ADDR	0x0000801003f4ull
+#define FF400_MIDI_RX_PORT_0	0x000080180000ull
+#define FF400_MIDI_RX_PORT_1	0x000080190000ull
+
+static int ff400_get_clock(struct snd_ff *ff, unsigned int *rate,
+			   enum snd_ff_clock_src *src)
+{
+	__le32 reg;
+	u32 data;
+	int err;
+
+	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
+				 FF400_CLOCK_CONFIG, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+	data = le32_to_cpu(reg);
+
+	/* Calculate sampling rate. */
+	switch ((data >> 1) & 0x03) {
+	case 0x01:
+		*rate = 32000;
+		break;
+	case 0x00:
+		*rate = 44100;
+		break;
+	case 0x03:
+		*rate = 48000;
+		break;
+	case 0x02:
+	default:
+		return -EIO;
+	}
+
+	if (data & 0x08)
+		*rate *= 2;
+	else if (data & 0x10)
+		*rate *= 4;
+
+	/* Calculate source of clock. */
+	if (data & 0x01) {
+		*src = SND_FF_CLOCK_SRC_INTERNAL;
+	} else {
+		/* TODO: 0x00, 0x01, 0x02, 0x06, 0x07? */
+		switch ((data >> 10) & 0x07) {
+		case 0x03:
+			*src = SND_FF_CLOCK_SRC_SPDIF;
+			break;
+		case 0x04:
+			*src = SND_FF_CLOCK_SRC_WORD;
+			break;
+		case 0x05:
+			*src = SND_FF_CLOCK_SRC_LTC;
+			break;
+		case 0x00:
+		default:
+			*src = SND_FF_CLOCK_SRC_ADAT;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int ff400_begin_session(struct snd_ff *ff, unsigned int rate)
+{
+	__le32 reg;
+	int i, err;
+
+	/* Check whether the given value is supported or not. */
+	for (i = 0; i < CIP_SFC_COUNT; i++) {
+		if (amdtp_rate_table[i] == rate)
+			break;
+	}
+	if (i == CIP_SFC_COUNT)
+		return -EINVAL;
+
+	/* Set the number of data blocks transferred in a second. */
+	reg = cpu_to_le32(rate);
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 FF400_STF, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+
+	msleep(100);
+
+	/*
+	 * Set isochronous channel and the number of quadlets of received
+	 * packets.
+	 */
+	reg = cpu_to_le32(((ff->rx_stream.data_block_quadlets << 3) << 8) |
+			  ff->rx_resources.channel);
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 FF400_RX_PACKET_FORMAT, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+
+	/*
+	 * Set isochronous channel and the number of quadlets of transmitted
+	 * packet.
+	 */
+	/* TODO: investigate the purpose of this 0x80. */
+	reg = cpu_to_le32((0x80 << 24) |
+			  (ff->tx_resources.channel << 5) |
+			  (ff->tx_stream.data_block_quadlets));
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 FF400_TX_PACKET_FORMAT, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return err;
+
+	/* Allow to transmit packets. */
+	reg = cpu_to_le32(0x00000001);
+	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				 FF400_ISOC_COMM_START, &reg, sizeof(reg), 0);
+}
+
+static void ff400_finish_session(struct snd_ff *ff)
+{
+	__le32 reg;
+
+	reg = cpu_to_le32(0x80000000);
+	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+			   FF400_ISOC_COMM_STOP, &reg, sizeof(reg), 0);
+}
+
+static int ff400_switch_fetching_mode(struct snd_ff *ff, bool enable)
+{
+	__le32 *reg;
+	int i;
+	int err;
+
+	reg = kcalloc(18, sizeof(__le32), GFP_KERNEL);
+	if (reg == NULL)
+		return -ENOMEM;
+
+	if (enable) {
+		/*
+		 * Each quadlet is corresponding to data channels in a data
+		 * blocks in reverse order. Precisely, quadlets for available
+		 * data channels should be enabled. Here, I take second best
+		 * to fetch PCM frames from all of data channels regardless of
+		 * stf.
+		 */
+		for (i = 0; i < 18; ++i)
+			reg[i] = cpu_to_le32(0x00000001);
+	}
+
+	err = snd_fw_transaction(ff->unit, TCODE_WRITE_BLOCK_REQUEST,
+				 FF400_FETCH_PCM_FRAMES, reg,
+				 sizeof(__le32) * 18, 0);
+	kfree(reg);
+	return err;
+}
+
+static void ff400_dump_sync_status(struct snd_ff *ff,
+				   struct snd_info_buffer *buffer)
+{
+	__le32 reg;
+	u32 data;
+	int err;
+
+	err = snd_fw_transaction(ff->unit, TCODE_READ_QUADLET_REQUEST,
+				 FF400_SYNC_STATUS, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return;
+
+	data = le32_to_cpu(reg);
+
+	snd_iprintf(buffer, "External source detection:\n");
+
+	snd_iprintf(buffer, "Word Clock:");
+	if ((data >> 24) & 0x20) {
+		if ((data >> 24) & 0x40)
+			snd_iprintf(buffer, "sync\n");
+		else
+			snd_iprintf(buffer, "lock\n");
+	} else {
+		snd_iprintf(buffer, "none\n");
+	}
+
+	snd_iprintf(buffer, "S/PDIF:");
+	if ((data >> 16) & 0x10) {
+		if ((data >> 16) & 0x04)
+			snd_iprintf(buffer, "sync\n");
+		else
+			snd_iprintf(buffer, "lock\n");
+	} else {
+		snd_iprintf(buffer, "none\n");
+	}
+
+	snd_iprintf(buffer, "ADAT:");
+	if ((data >> 8) & 0x04) {
+		if ((data >> 8) & 0x10)
+			snd_iprintf(buffer, "sync\n");
+		else
+			snd_iprintf(buffer, "lock\n");
+	} else {
+		snd_iprintf(buffer, "none\n");
+	}
+
+	snd_iprintf(buffer, "\nUsed external source:\n");
+
+	if (((data >> 22) & 0x07) == 0x07) {
+		snd_iprintf(buffer, "None\n");
+	} else {
+		switch ((data >> 22) & 0x07) {
+		case 0x00:
+			snd_iprintf(buffer, "ADAT:");
+			break;
+		case 0x03:
+			snd_iprintf(buffer, "S/PDIF:");
+			break;
+		case 0x04:
+			snd_iprintf(buffer, "Word:");
+			break;
+		case 0x07:
+			snd_iprintf(buffer, "Nothing:");
+			break;
+		case 0x01:
+		case 0x02:
+		case 0x05:
+		case 0x06:
+		default:
+			snd_iprintf(buffer, "unknown:");
+			break;
+		}
+
+		if ((data >> 25) & 0x07) {
+			switch ((data >> 25) & 0x07) {
+			case 0x01:
+				snd_iprintf(buffer, "32000\n");
+				break;
+			case 0x02:
+				snd_iprintf(buffer, "44100\n");
+				break;
+			case 0x03:
+				snd_iprintf(buffer, "48000\n");
+				break;
+			case 0x04:
+				snd_iprintf(buffer, "64000\n");
+				break;
+			case 0x05:
+				snd_iprintf(buffer, "88200\n");
+				break;
+			case 0x06:
+				snd_iprintf(buffer, "96000\n");
+				break;
+			case 0x07:
+				snd_iprintf(buffer, "128000\n");
+				break;
+			case 0x08:
+				snd_iprintf(buffer, "176400\n");
+				break;
+			case 0x09:
+				snd_iprintf(buffer, "192000\n");
+				break;
+			case 0x00:
+				snd_iprintf(buffer, "unknown\n");
+				break;
+			}
+		}
+	}
+
+	snd_iprintf(buffer, "Multiplied:");
+	snd_iprintf(buffer, "%d\n", (data & 0x3ff) * 250);
+}
+
+static void ff400_dump_clock_config(struct snd_ff *ff,
+				    struct snd_info_buffer *buffer)
+{
+	__le32 reg;
+	u32 data;
+	unsigned int rate;
+	const char *src;
+	int err;
+
+	err = snd_fw_transaction(ff->unit, TCODE_READ_BLOCK_REQUEST,
+				 FF400_CLOCK_CONFIG, &reg, sizeof(reg), 0);
+	if (err < 0)
+		return;
+
+	data = le32_to_cpu(reg);
+
+	snd_iprintf(buffer, "Output S/PDIF format: %s (Emphasis: %s)\n",
+		    (data & 0x20) ? "Professional" : "Consumer",
+		    (data & 0x40) ? "on" : "off");
+
+	snd_iprintf(buffer, "Optical output interface format: %s\n",
+		    ((data >> 8) & 0x01) ? "S/PDIF" : "ADAT");
+
+	snd_iprintf(buffer, "Word output single speed: %s\n",
+		    ((data >> 8) & 0x20) ? "on" : "off");
+
+	snd_iprintf(buffer, "S/PDIF input interface: %s\n",
+		    ((data >> 8) & 0x02) ? "Optical" : "Coaxial");
+
+	switch ((data >> 1) & 0x03) {
+	case 0x01:
+		rate = 32000;
+		break;
+	case 0x00:
+		rate = 44100;
+		break;
+	case 0x03:
+		rate = 48000;
+		break;
+	case 0x02:
+	default:
+		return;
+	}
+
+	if (data & 0x08)
+		rate *= 2;
+	else if (data & 0x10)
+		rate *= 4;
+
+	snd_iprintf(buffer, "Sampling rate: %d\n", rate);
+
+	if (data & 0x01) {
+		src = "Internal";
+	} else {
+		switch ((data >> 10) & 0x07) {
+		case 0x00:
+			src = "ADAT";
+			break;
+		case 0x03:
+			src = "S/PDIF";
+			break;
+		case 0x04:
+			src = "Word";
+			break;
+		case 0x05:
+			src = "LTC";
+			break;
+		default:
+			return;
+		}
+	}
+
+	snd_iprintf(buffer, "Sync to clock source: %s\n", src);
+}
+
+const struct snd_ff_protocol snd_ff_protocol_ff400 = {
+	.get_clock		= ff400_get_clock,
+	.begin_session		= ff400_begin_session,
+	.finish_session		= ff400_finish_session,
+	.switch_fetching_mode	= ff400_switch_fetching_mode,
+
+	.dump_sync_status	= ff400_dump_sync_status,
+	.dump_clock_config	= ff400_dump_clock_config,
+
+	.midi_high_addr_reg	= FF400_MIDI_HIGH_ADDR,
+	.midi_rx_port_0_reg	= FF400_MIDI_RX_PORT_0,
+	.midi_rx_port_1_reg	= FF400_MIDI_RX_PORT_1,
+};
diff --git a/sound/firewire/fireface/ff-stream.c b/sound/firewire/fireface/ff-stream.c
new file mode 100644
index 0000000..7888092
--- /dev/null
+++ b/sound/firewire/fireface/ff-stream.c
@@ -0,0 +1,282 @@
+/*
+ * ff-stream.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+#define CALLBACK_TIMEOUT_MS	200
+
+static int get_rate_mode(unsigned int rate, unsigned int *mode)
+{
+	int i;
+
+	for (i = 0; i < CIP_SFC_COUNT; i++) {
+		if (amdtp_rate_table[i] == rate)
+			break;
+	}
+
+	if (i == CIP_SFC_COUNT)
+		return -EINVAL;
+
+	*mode = ((int)i - 1) / 2;
+
+	return 0;
+}
+
+/*
+ * Fireface 400 manages isochronous channel number in 3 bit field. Therefore,
+ * we can allocate between 0 and 7 channel.
+ */
+static int keep_resources(struct snd_ff *ff, unsigned int rate)
+{
+	int mode;
+	int err;
+
+	err = get_rate_mode(rate, &mode);
+	if (err < 0)
+		return err;
+
+	/* Keep resources for in-stream. */
+	err = amdtp_ff_set_parameters(&ff->tx_stream, rate,
+				      ff->spec->pcm_capture_channels[mode]);
+	if (err < 0)
+		return err;
+	ff->tx_resources.channels_mask = 0x00000000000000ffuLL;
+	err = fw_iso_resources_allocate(&ff->tx_resources,
+			amdtp_stream_get_max_payload(&ff->tx_stream),
+			fw_parent_device(ff->unit)->max_speed);
+	if (err < 0)
+		return err;
+
+	/* Keep resources for out-stream. */
+	err = amdtp_ff_set_parameters(&ff->rx_stream, rate,
+				      ff->spec->pcm_playback_channels[mode]);
+	if (err < 0)
+		return err;
+	ff->rx_resources.channels_mask = 0x00000000000000ffuLL;
+	err = fw_iso_resources_allocate(&ff->rx_resources,
+			amdtp_stream_get_max_payload(&ff->rx_stream),
+			fw_parent_device(ff->unit)->max_speed);
+	if (err < 0)
+		fw_iso_resources_free(&ff->tx_resources);
+
+	return err;
+}
+
+static void release_resources(struct snd_ff *ff)
+{
+	fw_iso_resources_free(&ff->tx_resources);
+	fw_iso_resources_free(&ff->rx_resources);
+}
+
+static inline void finish_session(struct snd_ff *ff)
+{
+	ff->spec->protocol->finish_session(ff);
+	ff->spec->protocol->switch_fetching_mode(ff, false);
+}
+
+static int init_stream(struct snd_ff *ff, enum amdtp_stream_direction dir)
+{
+	int err;
+	struct fw_iso_resources *resources;
+	struct amdtp_stream *stream;
+
+	if (dir == AMDTP_IN_STREAM) {
+		resources = &ff->tx_resources;
+		stream = &ff->tx_stream;
+	} else {
+		resources = &ff->rx_resources;
+		stream = &ff->rx_stream;
+	}
+
+	err = fw_iso_resources_init(resources, ff->unit);
+	if (err < 0)
+		return err;
+
+	err = amdtp_ff_init(stream, ff->unit, dir);
+	if (err < 0)
+		fw_iso_resources_destroy(resources);
+
+	return err;
+}
+
+static void destroy_stream(struct snd_ff *ff, enum amdtp_stream_direction dir)
+{
+	if (dir == AMDTP_IN_STREAM) {
+		amdtp_stream_destroy(&ff->tx_stream);
+		fw_iso_resources_destroy(&ff->tx_resources);
+	} else {
+		amdtp_stream_destroy(&ff->rx_stream);
+		fw_iso_resources_destroy(&ff->rx_resources);
+	}
+}
+
+int snd_ff_stream_init_duplex(struct snd_ff *ff)
+{
+	int err;
+
+	err = init_stream(ff, AMDTP_OUT_STREAM);
+	if (err < 0)
+		goto end;
+
+	err = init_stream(ff, AMDTP_IN_STREAM);
+	if (err < 0)
+		destroy_stream(ff, AMDTP_OUT_STREAM);
+end:
+	return err;
+}
+
+/*
+ * This function should be called before starting streams or after stopping
+ * streams.
+ */
+void snd_ff_stream_destroy_duplex(struct snd_ff *ff)
+{
+	destroy_stream(ff, AMDTP_IN_STREAM);
+	destroy_stream(ff, AMDTP_OUT_STREAM);
+}
+
+int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate)
+{
+	unsigned int curr_rate;
+	enum snd_ff_clock_src src;
+	int err;
+
+	if (ff->substreams_counter == 0)
+		return 0;
+
+	err = ff->spec->protocol->get_clock(ff, &curr_rate, &src);
+	if (err < 0)
+		return err;
+	if (curr_rate != rate ||
+	    amdtp_streaming_error(&ff->tx_stream) ||
+	    amdtp_streaming_error(&ff->rx_stream)) {
+		finish_session(ff);
+
+		amdtp_stream_stop(&ff->tx_stream);
+		amdtp_stream_stop(&ff->rx_stream);
+
+		release_resources(ff);
+	}
+
+	/*
+	 * Regardless of current source of clock signal, drivers transfer some
+	 * packets. Then, the device transfers packets.
+	 */
+	if (!amdtp_stream_running(&ff->rx_stream)) {
+		err = keep_resources(ff, rate);
+		if (err < 0)
+			goto error;
+
+		err = ff->spec->protocol->begin_session(ff, rate);
+		if (err < 0)
+			goto error;
+
+		err = amdtp_stream_start(&ff->rx_stream,
+					 ff->rx_resources.channel,
+					 fw_parent_device(ff->unit)->max_speed);
+		if (err < 0)
+			goto error;
+
+		if (!amdtp_stream_wait_callback(&ff->rx_stream,
+						CALLBACK_TIMEOUT_MS)) {
+			err = -ETIMEDOUT;
+			goto error;
+		}
+
+		err = ff->spec->protocol->switch_fetching_mode(ff, true);
+		if (err < 0)
+			goto error;
+	}
+
+	if (!amdtp_stream_running(&ff->tx_stream)) {
+		err = amdtp_stream_start(&ff->tx_stream,
+					 ff->tx_resources.channel,
+					 fw_parent_device(ff->unit)->max_speed);
+		if (err < 0)
+			goto error;
+
+		if (!amdtp_stream_wait_callback(&ff->tx_stream,
+						CALLBACK_TIMEOUT_MS)) {
+			err = -ETIMEDOUT;
+			goto error;
+		}
+	}
+
+	return 0;
+error:
+	amdtp_stream_stop(&ff->tx_stream);
+	amdtp_stream_stop(&ff->rx_stream);
+
+	finish_session(ff);
+	release_resources(ff);
+
+	return err;
+}
+
+void snd_ff_stream_stop_duplex(struct snd_ff *ff)
+{
+	if (ff->substreams_counter > 0)
+		return;
+
+	amdtp_stream_stop(&ff->tx_stream);
+	amdtp_stream_stop(&ff->rx_stream);
+	finish_session(ff);
+	release_resources(ff);
+}
+
+void snd_ff_stream_update_duplex(struct snd_ff *ff)
+{
+	/* The device discontinue to transfer packets.  */
+	amdtp_stream_pcm_abort(&ff->tx_stream);
+	amdtp_stream_stop(&ff->tx_stream);
+
+	amdtp_stream_pcm_abort(&ff->rx_stream);
+	amdtp_stream_stop(&ff->rx_stream);
+
+	fw_iso_resources_update(&ff->tx_resources);
+	fw_iso_resources_update(&ff->rx_resources);
+}
+
+void snd_ff_stream_lock_changed(struct snd_ff *ff)
+{
+	ff->dev_lock_changed = true;
+	wake_up(&ff->hwdep_wait);
+}
+
+int snd_ff_stream_lock_try(struct snd_ff *ff)
+{
+	int err;
+
+	spin_lock_irq(&ff->lock);
+
+	/* user land lock this */
+	if (ff->dev_lock_count < 0) {
+		err = -EBUSY;
+		goto end;
+	}
+
+	/* this is the first time */
+	if (ff->dev_lock_count++ == 0)
+		snd_ff_stream_lock_changed(ff);
+	err = 0;
+end:
+	spin_unlock_irq(&ff->lock);
+	return err;
+}
+
+void snd_ff_stream_lock_release(struct snd_ff *ff)
+{
+	spin_lock_irq(&ff->lock);
+
+	if (WARN_ON(ff->dev_lock_count <= 0))
+		goto end;
+	if (--ff->dev_lock_count == 0)
+		snd_ff_stream_lock_changed(ff);
+end:
+	spin_unlock_irq(&ff->lock);
+}
diff --git a/sound/firewire/fireface/ff-transaction.c b/sound/firewire/fireface/ff-transaction.c
new file mode 100644
index 0000000..332b29f
--- /dev/null
+++ b/sound/firewire/fireface/ff-transaction.c
@@ -0,0 +1,295 @@
+/*
+ * ff-transaction.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port,
+				     int rcode)
+{
+	struct snd_rawmidi_substream *substream =
+				READ_ONCE(ff->rx_midi_substreams[port]);
+
+	if (rcode_is_permanent_error(rcode)) {
+		ff->rx_midi_error[port] = true;
+		return;
+	}
+
+	if (rcode != RCODE_COMPLETE) {
+		/* Transfer the message again, immediately. */
+		ff->next_ktime[port] = 0;
+		schedule_work(&ff->rx_midi_work[port]);
+		return;
+	}
+
+	snd_rawmidi_transmit_ack(substream, ff->rx_bytes[port]);
+	ff->rx_bytes[port] = 0;
+
+	if (!snd_rawmidi_transmit_empty(substream))
+		schedule_work(&ff->rx_midi_work[port]);
+}
+
+static void finish_transmit_midi0_msg(struct fw_card *card, int rcode,
+				      void *data, size_t length,
+				      void *callback_data)
+{
+	struct snd_ff *ff =
+		container_of(callback_data, struct snd_ff, transactions[0]);
+	finish_transmit_midi_msg(ff, 0, rcode);
+}
+
+static void finish_transmit_midi1_msg(struct fw_card *card, int rcode,
+				      void *data, size_t length,
+				      void *callback_data)
+{
+	struct snd_ff *ff =
+		container_of(callback_data, struct snd_ff, transactions[1]);
+	finish_transmit_midi_msg(ff, 1, rcode);
+}
+
+static inline void fill_midi_buf(struct snd_ff *ff, unsigned int port,
+				 unsigned int index, u8 byte)
+{
+	ff->msg_buf[port][index] = cpu_to_le32(byte);
+}
+
+static void transmit_midi_msg(struct snd_ff *ff, unsigned int port)
+{
+	struct snd_rawmidi_substream *substream =
+			READ_ONCE(ff->rx_midi_substreams[port]);
+	u8 *buf = (u8 *)ff->msg_buf[port];
+	int i, len;
+
+	struct fw_device *fw_dev = fw_parent_device(ff->unit);
+	unsigned long long addr;
+	int generation;
+	fw_transaction_callback_t callback;
+
+	if (substream == NULL || snd_rawmidi_transmit_empty(substream))
+		return;
+
+	if (ff->rx_bytes[port] > 0 || ff->rx_midi_error[port])
+		return;
+
+	/* Do it in next chance. */
+	if (ktime_after(ff->next_ktime[port], ktime_get())) {
+		schedule_work(&ff->rx_midi_work[port]);
+		return;
+	}
+
+	len = snd_rawmidi_transmit_peek(substream, buf,
+					SND_FF_MAXIMIM_MIDI_QUADS);
+	if (len <= 0)
+		return;
+
+	for (i = len - 1; i >= 0; i--)
+		fill_midi_buf(ff, port, i, buf[i]);
+
+	if (port == 0) {
+		addr = ff->spec->protocol->midi_rx_port_0_reg;
+		callback = finish_transmit_midi0_msg;
+	} else {
+		addr = ff->spec->protocol->midi_rx_port_1_reg;
+		callback = finish_transmit_midi1_msg;
+	}
+
+	/* Set interval to next transaction. */
+	ff->next_ktime[port] = ktime_add_ns(ktime_get(),
+					    len * 8 * NSEC_PER_SEC / 31250);
+	ff->rx_bytes[port] = len;
+
+	/*
+	 * In Linux FireWire core, when generation is updated with memory
+	 * barrier, node id has already been updated. In this module, After
+	 * this smp_rmb(), load/store instructions to memory are completed.
+	 * Thus, both of generation and node id are available with recent
+	 * values. This is a light-serialization solution to handle bus reset
+	 * events on IEEE 1394 bus.
+	 */
+	generation = fw_dev->generation;
+	smp_rmb();
+	fw_send_request(fw_dev->card, &ff->transactions[port],
+			TCODE_WRITE_BLOCK_REQUEST,
+			fw_dev->node_id, generation, fw_dev->max_speed,
+			addr, &ff->msg_buf[port], len * 4,
+			callback, &ff->transactions[port]);
+}
+
+static void transmit_midi0_msg(struct work_struct *work)
+{
+	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[0]);
+
+	transmit_midi_msg(ff, 0);
+}
+
+static void transmit_midi1_msg(struct work_struct *work)
+{
+	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[1]);
+
+	transmit_midi_msg(ff, 1);
+}
+
+static void handle_midi_msg(struct fw_card *card, struct fw_request *request,
+			    int tcode, int destination, int source,
+			    int generation, unsigned long long offset,
+			    void *data, size_t length, void *callback_data)
+{
+	struct snd_ff *ff = callback_data;
+	__le32 *buf = data;
+	u32 quad;
+	u8 byte;
+	unsigned int index;
+	struct snd_rawmidi_substream *substream;
+	int i;
+
+	fw_send_response(card, request, RCODE_COMPLETE);
+
+	for (i = 0; i < length / 4; i++) {
+		quad = le32_to_cpu(buf[i]);
+
+		/* Message in first port. */
+		/*
+		 * This value may represent the index of this unit when the same
+		 * units are on the same IEEE 1394 bus. This driver doesn't use
+		 * it.
+		 */
+		index = (quad >> 8) & 0xff;
+		if (index > 0) {
+			substream = READ_ONCE(ff->tx_midi_substreams[0]);
+			if (substream != NULL) {
+				byte = quad & 0xff;
+				snd_rawmidi_receive(substream, &byte, 1);
+			}
+		}
+
+		/* Message in second port. */
+		index = (quad >> 24) & 0xff;
+		if (index > 0) {
+			substream = READ_ONCE(ff->tx_midi_substreams[1]);
+			if (substream != NULL) {
+				byte = (quad >> 16) & 0xff;
+				snd_rawmidi_receive(substream, &byte, 1);
+			}
+		}
+	}
+}
+
+static int allocate_own_address(struct snd_ff *ff, int i)
+{
+	struct fw_address_region midi_msg_region;
+	int err;
+
+	ff->async_handler.length = SND_FF_MAXIMIM_MIDI_QUADS * 4;
+	ff->async_handler.address_callback = handle_midi_msg;
+	ff->async_handler.callback_data = ff;
+
+	midi_msg_region.start = 0x000100000000ull * i;
+	midi_msg_region.end = midi_msg_region.start + ff->async_handler.length;
+
+	err = fw_core_add_address_handler(&ff->async_handler, &midi_msg_region);
+	if (err >= 0) {
+		/* Controllers are allowed to register this region. */
+		if (ff->async_handler.offset & 0x0000ffffffff) {
+			fw_core_remove_address_handler(&ff->async_handler);
+			err = -EAGAIN;
+		}
+	}
+
+	return err;
+}
+
+/*
+ * The configuration to start asynchronous transactions for MIDI messages is in
+ * 0x'0000'8010'051c. This register includes the other options, thus this driver
+ * doesn't touch it and leaves the decision to userspace. The userspace MUST add
+ * 0x04000000 to write transactions to the register to receive any MIDI
+ * messages.
+ *
+ * Here, I just describe MIDI-related offsets of the register, in little-endian
+ * order.
+ *
+ * Controllers are allowed to register higher 4 bytes of address to receive
+ * the transactions. The register is 0x'0000'8010'03f4. On the other hand, the
+ * controllers are not allowed to register lower 4 bytes of the address. They
+ * are forced to select from 4 options by writing corresponding bits to
+ * 0x'0000'8010'051c.
+ *
+ * The 3rd-6th bits in MSB of this register are used to indicate lower 4 bytes
+ * of address to which the device transferrs the transactions.
+ *  - 6th: 0x'....'....'0000'0180
+ *  - 5th: 0x'....'....'0000'0100
+ *  - 4th: 0x'....'....'0000'0080
+ *  - 3rd: 0x'....'....'0000'0000
+ *
+ * This driver configure 0x'....'....'0000'0000 for units to receive MIDI
+ * messages. 3rd bit of the register should be configured, however this driver
+ * deligates this task to user space applications due to a restriction that
+ * this register is write-only and the other bits have own effects.
+ *
+ * The 1st and 2nd bits in LSB of this register are used to cancel transferring
+ * asynchronous transactions. These two bits have the same effect.
+ *  - 1st/2nd: cancel transferring
+ */
+int snd_ff_transaction_reregister(struct snd_ff *ff)
+{
+	struct fw_card *fw_card = fw_parent_device(ff->unit)->card;
+	u32 addr;
+	__le32 reg;
+
+	/*
+	 * Controllers are allowed to register its node ID and upper 2 byte of
+	 * local address to listen asynchronous transactions.
+	 */
+	addr = (fw_card->node_id << 16) | (ff->async_handler.offset >> 32);
+	reg = cpu_to_le32(addr);
+	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+				  ff->spec->protocol->midi_high_addr_reg,
+				  &reg, sizeof(reg), 0);
+}
+
+int snd_ff_transaction_register(struct snd_ff *ff)
+{
+	int i, err;
+
+	/*
+	 * Allocate in Memory Space of IEC 13213, but lower 4 byte in LSB should
+	 * be zero due to device specification.
+	 */
+	for (i = 0; i < 0xffff; i++) {
+		err = allocate_own_address(ff, i);
+		if (err != -EBUSY && err != -EAGAIN)
+			break;
+	}
+	if (err < 0)
+		return err;
+
+	err = snd_ff_transaction_reregister(ff);
+	if (err < 0)
+		return err;
+
+	INIT_WORK(&ff->rx_midi_work[0], transmit_midi0_msg);
+	INIT_WORK(&ff->rx_midi_work[1], transmit_midi1_msg);
+
+	return 0;
+}
+
+void snd_ff_transaction_unregister(struct snd_ff *ff)
+{
+	__le32 reg;
+
+	if (ff->async_handler.callback_data == NULL)
+		return;
+	ff->async_handler.callback_data = NULL;
+
+	/* Release higher 4 bytes of address. */
+	reg = cpu_to_le32(0x00000000);
+	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
+			   ff->spec->protocol->midi_high_addr_reg,
+			   &reg, sizeof(reg), 0);
+
+	fw_core_remove_address_handler(&ff->async_handler);
+}
diff --git a/sound/firewire/fireface/ff.c b/sound/firewire/fireface/ff.c
new file mode 100644
index 0000000..4974bc7
--- /dev/null
+++ b/sound/firewire/fireface/ff.c
@@ -0,0 +1,209 @@
+/*
+ * ff.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+#define OUI_RME	0x000a35
+
+MODULE_DESCRIPTION("RME Fireface series Driver");
+MODULE_AUTHOR("Takashi Sakamoto <o-takashi@sakamocchi.jp>");
+MODULE_LICENSE("GPL v2");
+
+static void name_card(struct snd_ff *ff)
+{
+	struct fw_device *fw_dev = fw_parent_device(ff->unit);
+
+	strcpy(ff->card->driver, "Fireface");
+	strcpy(ff->card->shortname, ff->spec->name);
+	strcpy(ff->card->mixername, ff->spec->name);
+	snprintf(ff->card->longname, sizeof(ff->card->longname),
+		 "RME %s, GUID %08x%08x at %s, S%d", ff->spec->name,
+		 fw_dev->config_rom[3], fw_dev->config_rom[4],
+		 dev_name(&ff->unit->device), 100 << fw_dev->max_speed);
+}
+
+static void ff_free(struct snd_ff *ff)
+{
+	snd_ff_stream_destroy_duplex(ff);
+	snd_ff_transaction_unregister(ff);
+
+	fw_unit_put(ff->unit);
+
+	mutex_destroy(&ff->mutex);
+	kfree(ff);
+}
+
+static void ff_card_free(struct snd_card *card)
+{
+	ff_free(card->private_data);
+}
+
+static void do_registration(struct work_struct *work)
+{
+	struct snd_ff *ff = container_of(work, struct snd_ff, dwork.work);
+	int err;
+
+	if (ff->registered)
+		return;
+
+	err = snd_card_new(&ff->unit->device, -1, NULL, THIS_MODULE, 0,
+			   &ff->card);
+	if (err < 0)
+		return;
+
+	err = snd_ff_transaction_register(ff);
+	if (err < 0)
+		goto error;
+
+	name_card(ff);
+
+	err = snd_ff_stream_init_duplex(ff);
+	if (err < 0)
+		goto error;
+
+	snd_ff_proc_init(ff);
+
+	err = snd_ff_create_midi_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_pcm_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_ff_create_hwdep_devices(ff);
+	if (err < 0)
+		goto error;
+
+	err = snd_card_register(ff->card);
+	if (err < 0)
+		goto error;
+
+	ff->card->private_free = ff_card_free;
+	ff->card->private_data = ff;
+	ff->registered = true;
+
+	return;
+error:
+	snd_ff_transaction_unregister(ff);
+	snd_ff_stream_destroy_duplex(ff);
+	snd_card_free(ff->card);
+	dev_info(&ff->unit->device,
+		 "Sound card registration failed: %d\n", err);
+}
+
+static int snd_ff_probe(struct fw_unit *unit,
+			   const struct ieee1394_device_id *entry)
+{
+	struct snd_ff *ff;
+
+	ff = kzalloc(sizeof(struct snd_ff), GFP_KERNEL);
+	if (ff == NULL)
+		return -ENOMEM;
+
+	/* initialize myself */
+	ff->unit = fw_unit_get(unit);
+	dev_set_drvdata(&unit->device, ff);
+
+	mutex_init(&ff->mutex);
+	spin_lock_init(&ff->lock);
+	init_waitqueue_head(&ff->hwdep_wait);
+
+	ff->spec = (const struct snd_ff_spec *)entry->driver_data;
+
+	/* Register this sound card later. */
+	INIT_DEFERRABLE_WORK(&ff->dwork, do_registration);
+	snd_fw_schedule_registration(unit, &ff->dwork);
+
+	return 0;
+}
+
+static void snd_ff_update(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	/* Postpone a workqueue for deferred registration. */
+	if (!ff->registered)
+		snd_fw_schedule_registration(unit, &ff->dwork);
+
+	snd_ff_transaction_reregister(ff);
+
+	if (ff->registered)
+		snd_ff_stream_update_duplex(ff);
+}
+
+static void snd_ff_remove(struct fw_unit *unit)
+{
+	struct snd_ff *ff = dev_get_drvdata(&unit->device);
+
+	/*
+	 * Confirm to stop the work for registration before the sound card is
+	 * going to be released. The work is not scheduled again because bus
+	 * reset handler is not called anymore.
+	 */
+	cancel_work_sync(&ff->dwork.work);
+
+	if (ff->registered) {
+		/* No need to wait for releasing card object in this context. */
+		snd_card_free_when_closed(ff->card);
+	} else {
+		/* Don't forget this case. */
+		ff_free(ff);
+	}
+}
+
+static const struct snd_ff_spec spec_ff400 = {
+	.name = "Fireface400",
+	.pcm_capture_channels = {18, 14, 10},
+	.pcm_playback_channels = {18, 14, 10},
+	.midi_in_ports = 2,
+	.midi_out_ports = 2,
+	.protocol = &snd_ff_protocol_ff400,
+};
+
+static const struct ieee1394_device_id snd_ff_id_table[] = {
+	/* Fireface 400 */
+	{
+		.match_flags	= IEEE1394_MATCH_VENDOR_ID |
+				  IEEE1394_MATCH_SPECIFIER_ID |
+				  IEEE1394_MATCH_VERSION |
+				  IEEE1394_MATCH_MODEL_ID,
+		.vendor_id	= OUI_RME,
+		.specifier_id	= 0x000a35,
+		.version	= 0x000002,
+		.model_id	= 0x101800,
+		.driver_data	= (kernel_ulong_t)&spec_ff400,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(ieee1394, snd_ff_id_table);
+
+static struct fw_driver ff_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "snd-fireface",
+		.bus	= &fw_bus_type,
+	},
+	.probe    = snd_ff_probe,
+	.update   = snd_ff_update,
+	.remove   = snd_ff_remove,
+	.id_table = snd_ff_id_table,
+};
+
+static int __init snd_ff_init(void)
+{
+	return driver_register(&ff_driver.driver);
+}
+
+static void __exit snd_ff_exit(void)
+{
+	driver_unregister(&ff_driver.driver);
+}
+
+module_init(snd_ff_init);
+module_exit(snd_ff_exit);
diff --git a/sound/firewire/fireface/ff.h b/sound/firewire/fireface/ff.h
new file mode 100644
index 0000000..64df44b
--- /dev/null
+++ b/sound/firewire/fireface/ff.h
@@ -0,0 +1,146 @@
+/*
+ * ff.h - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#ifndef SOUND_FIREFACE_H_INCLUDED
+#define SOUND_FIREFACE_H_INCLUDED
+
+#include <linux/device.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/compat.h>
+#include <linux/sched/signal.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/rawmidi.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/hwdep.h>
+#include <sound/firewire.h>
+
+#include "../lib.h"
+#include "../amdtp-stream.h"
+#include "../iso-resources.h"
+
+#define SND_FF_STREAM_MODES		3
+
+#define SND_FF_MAXIMIM_MIDI_QUADS	9
+#define SND_FF_IN_MIDI_PORTS		2
+#define SND_FF_OUT_MIDI_PORTS		2
+
+struct snd_ff_protocol;
+struct snd_ff_spec {
+	const char *const name;
+
+	const unsigned int pcm_capture_channels[SND_FF_STREAM_MODES];
+	const unsigned int pcm_playback_channels[SND_FF_STREAM_MODES];
+
+	unsigned int midi_in_ports;
+	unsigned int midi_out_ports;
+
+	const struct snd_ff_protocol *protocol;
+};
+
+struct snd_ff {
+	struct snd_card *card;
+	struct fw_unit *unit;
+	struct mutex mutex;
+	spinlock_t lock;
+
+	bool registered;
+	struct delayed_work dwork;
+
+	const struct snd_ff_spec *spec;
+
+	/* To handle MIDI tx. */
+	struct snd_rawmidi_substream *tx_midi_substreams[SND_FF_IN_MIDI_PORTS];
+	struct fw_address_handler async_handler;
+
+	/* TO handle MIDI rx. */
+	struct snd_rawmidi_substream *rx_midi_substreams[SND_FF_OUT_MIDI_PORTS];
+	u8 running_status[SND_FF_OUT_MIDI_PORTS];
+	__le32 msg_buf[SND_FF_OUT_MIDI_PORTS][SND_FF_MAXIMIM_MIDI_QUADS];
+	struct work_struct rx_midi_work[SND_FF_OUT_MIDI_PORTS];
+	struct fw_transaction transactions[SND_FF_OUT_MIDI_PORTS];
+	ktime_t next_ktime[SND_FF_OUT_MIDI_PORTS];
+	bool rx_midi_error[SND_FF_OUT_MIDI_PORTS];
+	unsigned int rx_bytes[SND_FF_OUT_MIDI_PORTS];
+
+	unsigned int substreams_counter;
+	struct amdtp_stream tx_stream;
+	struct amdtp_stream rx_stream;
+	struct fw_iso_resources tx_resources;
+	struct fw_iso_resources rx_resources;
+
+	int dev_lock_count;
+	bool dev_lock_changed;
+	wait_queue_head_t hwdep_wait;
+};
+
+enum snd_ff_clock_src {
+	SND_FF_CLOCK_SRC_INTERNAL,
+	SND_FF_CLOCK_SRC_SPDIF,
+	SND_FF_CLOCK_SRC_ADAT,
+	SND_FF_CLOCK_SRC_WORD,
+	SND_FF_CLOCK_SRC_LTC,
+	/* TODO: perhaps ADAT2 and TCO exists. */
+};
+
+struct snd_ff_protocol {
+	int (*get_clock)(struct snd_ff *ff, unsigned int *rate,
+			 enum snd_ff_clock_src *src);
+	int (*begin_session)(struct snd_ff *ff, unsigned int rate);
+	void (*finish_session)(struct snd_ff *ff);
+	int (*switch_fetching_mode)(struct snd_ff *ff, bool enable);
+
+	void (*dump_sync_status)(struct snd_ff *ff,
+				 struct snd_info_buffer *buffer);
+	void (*dump_clock_config)(struct snd_ff *ff,
+				  struct snd_info_buffer *buffer);
+
+	u64 midi_high_addr_reg;
+	u64 midi_rx_port_0_reg;
+	u64 midi_rx_port_1_reg;
+};
+
+extern const struct snd_ff_protocol snd_ff_protocol_ff400;
+
+int snd_ff_transaction_register(struct snd_ff *ff);
+int snd_ff_transaction_reregister(struct snd_ff *ff);
+void snd_ff_transaction_unregister(struct snd_ff *ff);
+
+int amdtp_ff_set_parameters(struct amdtp_stream *s, unsigned int rate,
+			    unsigned int pcm_channels);
+int amdtp_ff_add_pcm_hw_constraints(struct amdtp_stream *s,
+				    struct snd_pcm_runtime *runtime);
+int amdtp_ff_init(struct amdtp_stream *s, struct fw_unit *unit,
+		  enum amdtp_stream_direction dir);
+
+int snd_ff_stream_init_duplex(struct snd_ff *ff);
+void snd_ff_stream_destroy_duplex(struct snd_ff *ff);
+int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate);
+void snd_ff_stream_stop_duplex(struct snd_ff *ff);
+void snd_ff_stream_update_duplex(struct snd_ff *ff);
+
+void snd_ff_stream_lock_changed(struct snd_ff *ff);
+int snd_ff_stream_lock_try(struct snd_ff *ff);
+void snd_ff_stream_lock_release(struct snd_ff *ff);
+
+void snd_ff_proc_init(struct snd_ff *ff);
+
+int snd_ff_create_midi_devices(struct snd_ff *ff);
+
+int snd_ff_create_pcm_devices(struct snd_ff *ff);
+
+int snd_ff_create_hwdep_devices(struct snd_ff *ff);
+
+#endif