ALSA: oxfw: Add support for capture/playback MIDI messages

This commit adds MIDI functionality with an assumption of 'if the device
has MIDI comformant data channels in its stream formation, the device has
one MIDI port'.

When no streams have already started, MIDI functionality starts stream
with current sampling rate.

When MIDI functionality has already starts some streams and PCM
functionality is going to start streams at different sampling rate,
this driver stops streams once and changes sampling rate, then restarts
streams for both PCM/MIDI substreams.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/oxfw/Makefile

 snd-oxfw-objs := oxfw-command.o oxfw-stream.o oxfw-control.o oxfw-pcm.o \
-		 oxfw-proc.o oxfw.o
+		 oxfw-proc.o oxfw-midi.o oxfw.o
 obj-m += snd-oxfw.o

sound/firewire/oxfw/oxfw-midi.c

+/*
+ * oxfw_midi.c - a part of driver for OXFW970/971 based devices
+ *
+ * Copyright (c) 2014 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "oxfw.h"
+
+static int midi_capture_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_oxfw *oxfw = substream->rmidi->private_data;
+	int err;
+
+	mutex_lock(&oxfw->mutex);
+
+	oxfw->capture_substreams++;
+	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->tx_stream, 0, 0);
+
+	mutex_unlock(&oxfw->mutex);
+
+	return err;
+}
+
+static int midi_playback_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_oxfw *oxfw = substream->rmidi->private_data;
+	int err;
+
+	mutex_lock(&oxfw->mutex);
+
+	oxfw->playback_substreams++;
+	err = snd_oxfw_stream_start_simplex(oxfw, &oxfw->rx_stream, 0, 0);
+
+	mutex_unlock(&oxfw->mutex);
+
+	return err;
+}
+
+static int midi_capture_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_oxfw *oxfw = substream->rmidi->private_data;
+
+	mutex_lock(&oxfw->mutex);
+
+	oxfw->capture_substreams--;
+	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->tx_stream);
+
+	mutex_unlock(&oxfw->mutex);
+
+	return 0;
+}
+
+static int midi_playback_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_oxfw *oxfw = substream->rmidi->private_data;
+
+	mutex_lock(&oxfw->mutex);
+
+	oxfw->playback_substreams--;
+	snd_oxfw_stream_stop_simplex(oxfw, &oxfw->rx_stream);
+
+	mutex_unlock(&oxfw->mutex);
+
+	return 0;
+}
+
+static void midi_capture_trigger(struct snd_rawmidi_substream *substrm, int up)
+{
+	struct snd_oxfw *oxfw = substrm->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&oxfw->lock, flags);
+
+	if (up)
+		amdtp_stream_midi_trigger(&oxfw->tx_stream,
+					  substrm->number, substrm);
+	else
+		amdtp_stream_midi_trigger(&oxfw->tx_stream,
+					  substrm->number, NULL);
+
+	spin_unlock_irqrestore(&oxfw->lock, flags);
+}
+
+static void midi_playback_trigger(struct snd_rawmidi_substream *substrm, int up)
+{
+	struct snd_oxfw *oxfw = substrm->rmidi->private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&oxfw->lock, flags);
+
+	if (up)
+		amdtp_stream_midi_trigger(&oxfw->rx_stream,
+					  substrm->number, substrm);
+	else
+		amdtp_stream_midi_trigger(&oxfw->rx_stream,
+					  substrm->number, NULL);
+
+	spin_unlock_irqrestore(&oxfw->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_oxfw *oxfw,
+				     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",
+			 oxfw->card->shortname, subs->number + 1);
+	}
+}
+
+int snd_oxfw_create_midi(struct snd_oxfw *oxfw)
+{
+	struct snd_oxfw_stream_formation formation;
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *str;
+	u8 *format;
+	int i, err;
+
+	/* If its stream has MIDI conformant data channel, add one MIDI port */
+	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+		format = oxfw->tx_stream_formats[i];
+		if (format != NULL) {
+			err = snd_oxfw_stream_parse_format(format, &formation);
+			if (err >= 0 && formation.midi > 0)
+				oxfw->midi_input_ports = 1;
+		}
+
+		format = oxfw->rx_stream_formats[i];
+		if (format != NULL) {
+			err = snd_oxfw_stream_parse_format(format, &formation);
+			if (err >= 0 && formation.midi > 0)
+				oxfw->midi_output_ports = 1;
+		}
+	}
+	if ((oxfw->midi_input_ports == 0) && (oxfw->midi_output_ports == 0))
+		return 0;
+
+	/* create midi ports */
+	err = snd_rawmidi_new(oxfw->card, oxfw->card->driver, 0,
+			      oxfw->midi_output_ports, oxfw->midi_input_ports,
+			      &rmidi);
+	if (err < 0)
+		return err;
+
+	snprintf(rmidi->name, sizeof(rmidi->name),
+		 "%s MIDI", oxfw->card->shortname);
+	rmidi->private_data = oxfw;
+
+	if (oxfw->midi_input_ports > 0) {
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &midi_capture_ops);
+
+		str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT];
+
+		set_midi_substream_names(oxfw, str);
+	}
+
+	if (oxfw->midi_output_ports > 0) {
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &midi_playback_ops);
+
+		str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT];
+
+		set_midi_substream_names(oxfw, str);
+	}
+
+	if ((oxfw->midi_output_ports > 0) && (oxfw->midi_input_ports > 0))
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	return 0;
+}

sound/firewire/oxfw/oxfw-stream.c

@@ -282,6 +282,10 @@ int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw,
 	err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
 	if (err < 0)
 		goto end;
+	if (rate == 0)
+		rate = formation.rate;
+	if (pcm_channels == 0)
+		pcm_channels = formation.pcm;
 
 	if ((formation.rate != rate) || (formation.pcm != pcm_channels)) {
 		if (opposite != NULL) {

sound/firewire/oxfw/oxfw.c

@@ -138,6 +138,7 @@ static int oxfw_probe(struct fw_unit *unit,
 	mutex_init(&oxfw->mutex);
 	oxfw->unit = unit;
 	oxfw->device_info = (const struct device_info *)id->driver_data;
+	spin_lock_init(&oxfw->lock);
 
 	err = snd_oxfw_stream_discover(oxfw);
 	if (err < 0)
@@ -159,6 +160,10 @@ static int oxfw_probe(struct fw_unit *unit,
 
 	snd_oxfw_proc_init(oxfw);
 
+	err = snd_oxfw_create_midi(oxfw);
+	if (err < 0)
+		goto error;
+
 	err = snd_oxfw_stream_init_simplex(oxfw, &oxfw->rx_stream);
 	if (err < 0)
 		goto error;

sound/firewire/oxfw/oxfw.h

@@ -19,6 +19,7 @@
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/info.h>
+#include <sound/rawmidi.h>
 
 #include "../lib.h"
 #include "../fcp.h"
@@ -43,6 +44,7 @@ struct snd_oxfw {
 	struct fw_unit *unit;
 	const struct device_info *device_info;
 	struct mutex mutex;
+	spinlock_t lock;
 
 	bool has_output;
 	u8 *tx_stream_formats[SND_OXFW_STREAM_FORMAT_ENTRIES];
@@ -55,6 +57,9 @@ struct snd_oxfw {
 	unsigned int capture_substreams;
 	unsigned int playback_substreams;
 
+	unsigned int midi_input_ports;
+	unsigned int midi_output_ports;
+
 	bool mute;
 	s16 volume[6];
 	s16 volume_min;
@@ -124,3 +129,5 @@ int snd_oxfw_create_pcm(struct snd_oxfw *oxfw);
 int snd_oxfw_create_mixer(struct snd_oxfw *oxfw);
 
 void snd_oxfw_proc_init(struct snd_oxfw *oxfw);
+
+int snd_oxfw_create_midi(struct snd_oxfw *oxfw);