ALSA: dice: Add support for MIDI capture/playback

This commit adds a support for MIDI capture/playback

When MIDI substrams already start streaming and PCM substreams are going to
join at different sampling rate, streams are stopped once. Then sampling rate
is changed and streams are restarted.
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/dice/Makefile

-snd-dice-objs := dice-transaction.o dice-stream.o dice-proc.o dice-pcm.o \
-		 dice-hwdep.o dice.o
+snd-dice-objs := dice-transaction.o dice-stream.o dice-proc.o dice-midi.o \
+		 dice-pcm.o dice-hwdep.o dice.o
 obj-m += snd-dice.o

sound/firewire/dice/dice-midi.c

+/*
+ * 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_stream_midi_trigger(&dice->tx_stream,
+					  substrm->number, substrm);
+	else
+		amdtp_stream_midi_trigger(&dice->tx_stream,
+					  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_stream_midi_trigger(&dice->rx_stream,
+					  substrm->number, substrm);
+	else
+		amdtp_stream_midi_trigger(&dice->rx_stream,
+					  substrm->number, NULL);
+
+	spin_unlock_irqrestore(&dice->lock, flags);
+}
+
+static struct snd_rawmidi_ops capture_ops = {
+	.open		= midi_open,
+	.close		= midi_close,
+	.trigger	= midi_capture_trigger,
+};
+
+static struct snd_rawmidi_ops playback_ops = {
+	.open		= midi_open,
+	.close		= midi_close,
+	.trigger	= midi_playback_trigger,
+};
+
+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)
+{
+	struct snd_rawmidi *rmidi;
+	struct snd_rawmidi_str *str;
+	unsigned int i, midi_in_ports, midi_out_ports;
+	int err;
+
+	midi_in_ports = midi_out_ports = 0;
+	for (i = 0; i < 3; i++) {
+		midi_in_ports = max(dice->tx_midi_ports[i], midi_in_ports);
+		midi_out_ports = max(dice->rx_midi_ports[i], midi_out_ports);
+	}
+
+	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;
+}

sound/firewire/dice/dice-stream.c

@@ -218,6 +218,8 @@ int snd_dice_stream_start_duplex(struct snd_dice *dice, unsigned int rate)
 			"fail to get sampling rate\n");
 		goto end;
 	}
+	if (rate == 0)
+		rate = curr_rate;
 	if (rate != curr_rate)
 		stop_stream(dice, master);
 

sound/firewire/dice/dice.c

@@ -279,6 +279,10 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 
 	snd_dice_create_proc(dice);
 
+	err = snd_dice_create_midi(dice);
+	if (err < 0)
+		goto error;
+
 	err = snd_dice_stream_init_duplex(dice);
 	if (err < 0)
 		goto error;

sound/firewire/dice/dice.h

@@ -32,6 +32,7 @@
 #include <sound/initval.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
+#include <sound/rawmidi.h>
 
 #include "../amdtp.h"
 #include "../iso-resources.h"
@@ -183,4 +184,6 @@ int snd_dice_create_hwdep(struct snd_dice *dice);
 
 void snd_dice_create_proc(struct snd_dice *dice);
 
+int snd_dice_create_midi(struct snd_dice *dice);
+
 #endif