v4.19.13 snapshot.
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;
+}