[alsa-devel] [PATCH 05/11] fireface: add support for MIDI functionality

[Takashi Sakamoto]

In previous commit, fireface driver supports transaction functionality.
This commit adds MIDI functionality for userspace.

Userspace applications can always disable this functionality by sending
invalid values to 0x0000801003f4 and 0x00008010051c by write transactions.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/fireface/Makefile        |   2 +-
 sound/firewire/fireface/fireface-midi.c | 131 ++++++++++++++++++++++++++++++++
 sound/firewire/fireface/fireface.c      |   5 ++
 sound/firewire/fireface/fireface.h      |   3 +
 4 files changed, 140 insertions(+), 1 deletion(-)
 create mode 100644 sound/firewire/fireface/fireface-midi.c

diff --git a/sound/firewire/fireface/Makefile b/sound/firewire/fireface/Makefile
index aa52e41..2174b4b 100644
--- a/sound/firewire/fireface/Makefile
+++ b/sound/firewire/fireface/Makefile
@@ -1,2 +1,2 @@
-snd-fireface-objs := fireface.o fireface-transaction.o
+snd-fireface-objs := fireface.o fireface-transaction.o fireface-midi.o
 obj-$(CONFIG_SND_FIREFACE) += snd-fireface.o
diff --git a/sound/firewire/fireface/fireface-midi.c b/sound/firewire/fireface/fireface-midi.c
new file mode 100644
index 0000000..d324f4e7
--- /dev/null
+++ b/sound/firewire/fireface/fireface-midi.c
@@ -0,0 +1,131 @@
+/*
+ * fireface-midi.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2016 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "fireface.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;
+
+	ACCESS_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]);
+	ACCESS_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)
+		ACCESS_ONCE(ff->tx_midi_substreams[substream->number]) =
+								substream;
+	else
+		ACCESS_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 struct snd_rawmidi_ops midi_capture_ops = {
+	.open		= midi_capture_open,
+	.close		= midi_capture_close,
+	.trigger	= midi_capture_trigger,
+};
+
+static struct snd_rawmidi_ops midi_playback_ops = {
+	.open		= midi_playback_open,
+	.close		= midi_playback_close,
+	.trigger	= midi_playback_trigger,
+};
+
+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)
+{
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *stream;
+	int err;
+
+	err = snd_rawmidi_new(ff->card, ff->card->driver, 0,
+			      SND_FF_OUT_MIDI_PORTS, SND_FF_IN_MIDI_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/fireface.c b/sound/firewire/fireface/fireface.c
index b3ee869..0883cda 100644
--- a/sound/firewire/fireface/fireface.c
+++ b/sound/firewire/fireface/fireface.c
@@ -61,6 +61,10 @@ static void do_probe(struct work_struct *work)
 	if (err < 0)
 		goto end;
 
+	err = snd_ff_create_midi_devices(ff);
+	if (err < 0)
+		goto end;
+
 	err = snd_card_register(ff->card);
 	if (err < 0)
 		goto end;
@@ -98,6 +102,7 @@ static int snd_ff_probe(struct fw_unit *unit,
 	ff->unit = fw_unit_get(unit);
 
 	mutex_init(&ff->mutex);
+	spin_lock_init(&ff->lock);
 	dev_set_drvdata(&unit->device, ff);
 
 	ff->spec = (const struct snd_ff_spec *)entry->driver_data;
diff --git a/sound/firewire/fireface/fireface.h b/sound/firewire/fireface/fireface.h
index 6d132f9..33d94b8 100644
--- a/sound/firewire/fireface/fireface.h
+++ b/sound/firewire/fireface/fireface.h
@@ -43,6 +43,7 @@ struct snd_ff {
 	struct snd_card *card;
 	struct fw_unit *unit;
 	struct mutex mutex;
+	spinlock_t lock;
 
 	bool probed;
 	struct delayed_work dwork;
@@ -75,4 +76,6 @@ 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 snd_ff_create_midi_devices(struct snd_ff *ff);
+
 #endif
-- 
2.5.0