v4.19.13 snapshot.
diff --git a/sound/firewire/dice/dice-midi.c b/sound/firewire/dice/dice-midi.c
new file mode 100644
index 0000000..84eca8a
--- /dev/null
+++ b/sound/firewire/dice/dice-midi.c
@@ -0,0 +1,157 @@
+/*
+ * dice_midi.c - a part of driver for Dice based devices
+ *
+ * Copyright (c) 2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+#include "dice.h"
+
+static int midi_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_dice *dice = substream->rmidi->private_data;
+	int err;
+
+	err = snd_dice_stream_lock_try(dice);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&dice->mutex);
+
+	dice->substreams_counter++;
+	err = snd_dice_stream_start_duplex(dice, 0);
+
+	mutex_unlock(&dice->mutex);
+
+	if (err < 0)
+		snd_dice_stream_lock_release(dice);
+
+	return err;
+}
+
+static int midi_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_dice *dice = substream->rmidi->private_data;
+
+	mutex_lock(&dice->mutex);
+
+	dice->substreams_counter--;
+	snd_dice_stream_stop_duplex(dice);
+
+	mutex_unlock(&dice->mutex);
+
+	snd_dice_stream_lock_release(dice);
+	return 0;
+}
+
+static void midi_capture_trigger(struct snd_rawmidi_substream *substrm, int up)
+{
+	struct snd_dice *dice = substrm->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dice->lock, flags);
+
+	if (up)
+		amdtp_am824_midi_trigger(&dice->tx_stream[0],
+					  substrm->number, substrm);
+	else
+		amdtp_am824_midi_trigger(&dice->tx_stream[0],
+					  substrm->number, NULL);
+
+	spin_unlock_irqrestore(&dice->lock, flags);
+}
+
+static void midi_playback_trigger(struct snd_rawmidi_substream *substrm, int up)
+{
+	struct snd_dice *dice = substrm->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dice->lock, flags);
+
+	if (up)
+		amdtp_am824_midi_trigger(&dice->rx_stream[0],
+					 substrm->number, substrm);
+	else
+		amdtp_am824_midi_trigger(&dice->rx_stream[0],
+					 substrm->number, NULL);
+
+	spin_unlock_irqrestore(&dice->lock, flags);
+}
+
+static void set_midi_substream_names(struct snd_dice *dice,
+				     struct snd_rawmidi_str *str)
+{
+	struct snd_rawmidi_substream *subs;
+
+	list_for_each_entry(subs, &str->substreams, list) {
+		snprintf(subs->name, sizeof(subs->name),
+			 "%s MIDI %d", dice->card->shortname, subs->number + 1);
+	}
+}
+
+int snd_dice_create_midi(struct snd_dice *dice)
+{
+	static const struct snd_rawmidi_ops capture_ops = {
+		.open		= midi_open,
+		.close		= midi_close,
+		.trigger	= midi_capture_trigger,
+	};
+	static const struct snd_rawmidi_ops playback_ops = {
+		.open		= midi_open,
+		.close		= midi_close,
+		.trigger	= midi_playback_trigger,
+	};
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *str;
+	unsigned int midi_in_ports, midi_out_ports;
+	int i;
+	int err;
+
+	midi_in_ports = 0;
+	midi_out_ports = 0;
+	for (i = 0; i < MAX_STREAMS; ++i) {
+		midi_in_ports = max(midi_in_ports, dice->tx_midi_ports[i]);
+		midi_out_ports = max(midi_out_ports, dice->rx_midi_ports[i]);
+	}
+
+	if (midi_in_ports + midi_out_ports == 0)
+		return 0;
+
+	/* create midi ports */
+	err = snd_rawmidi_new(dice->card, dice->card->driver, 0,
+			      midi_out_ports, midi_in_ports,
+			      &rmidi);
+	if (err < 0)
+		return err;
+
+	snprintf(rmidi->name, sizeof(rmidi->name),
+		 "%s MIDI", dice->card->shortname);
+	rmidi->private_data = dice;
+
+	if (midi_in_ports > 0) {
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &capture_ops);
+
+		str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT];
+
+		set_midi_substream_names(dice, str);
+	}
+
+	if (midi_out_ports > 0) {
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &playback_ops);
+
+		str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT];
+
+		set_midi_substream_names(dice, str);
+	}
+
+	if ((midi_out_ports > 0) && (midi_in_ports > 0))
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	return 0;
+}