linux/sound/firewire/motu/motu-midi.c
Takashi Sakamoto 8edc56ec8f ALSA: firewire-motu: reserve/release isochronous resources in pcm.hw_params/hw_free callbacks
Once allocated, isochronous resources are available for packet
streaming, even if the streaming is cancelled. For this reason,
current implementation handles allocation of the resources and
starting packet streaming at the same time. However, this brings
complicated procedure to start packet streaming.

This commit separates the allocation and starting. The allocation is
done in pcm.hw_params callback and available till pcm.hw_free callback.
Even if any XRUN occurs, pcm.prepare callback is done to restart
packet streaming without releasing/allocating the resources.

There are two points to stop packet streaming; in pcm.hw_params and
pcm.prepare callbacks. The former point is a case that packet streaming
is already started for any MIDI substream then packet streaming is
requested with different sampling transfer frequency for any PCM
substream. The latter point is cases of any XRUN or packet queueing
error.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-06-18 08:45:31 +02:00

137 lines
3.2 KiB
C

/*
* motu-midi.h - a part of driver for MOTU FireWire series
*
* Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
*
* Licensed under the terms of the GNU General Public License, version 2.
*/
#include "motu.h"
static int midi_open(struct snd_rawmidi_substream *substream)
{
struct snd_motu *motu = substream->rmidi->private_data;
int err;
err = snd_motu_stream_lock_try(motu);
if (err < 0)
return err;
mutex_lock(&motu->mutex);
err = snd_motu_stream_reserve_duplex(motu, 0);
if (err >= 0) {
++motu->substreams_counter;
err = snd_motu_stream_start_duplex(motu);
}
mutex_unlock(&motu->mutex);
if (err < 0)
snd_motu_stream_lock_release(motu);
return err;
}
static int midi_close(struct snd_rawmidi_substream *substream)
{
struct snd_motu *motu = substream->rmidi->private_data;
mutex_lock(&motu->mutex);
--motu->substreams_counter;
snd_motu_stream_stop_duplex(motu);
snd_motu_stream_release_duplex(motu);
mutex_unlock(&motu->mutex);
snd_motu_stream_lock_release(motu);
return 0;
}
static void midi_capture_trigger(struct snd_rawmidi_substream *substrm, int up)
{
struct snd_motu *motu = substrm->rmidi->private_data;
unsigned long flags;
spin_lock_irqsave(&motu->lock, flags);
if (up)
amdtp_motu_midi_trigger(&motu->tx_stream, substrm->number,
substrm);
else
amdtp_motu_midi_trigger(&motu->tx_stream, substrm->number,
NULL);
spin_unlock_irqrestore(&motu->lock, flags);
}
static void midi_playback_trigger(struct snd_rawmidi_substream *substrm, int up)
{
struct snd_motu *motu = substrm->rmidi->private_data;
unsigned long flags;
spin_lock_irqsave(&motu->lock, flags);
if (up)
amdtp_motu_midi_trigger(&motu->rx_stream, substrm->number,
substrm);
else
amdtp_motu_midi_trigger(&motu->rx_stream, substrm->number,
NULL);
spin_unlock_irqrestore(&motu->lock, flags);
}
static void set_midi_substream_names(struct snd_motu *motu,
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", motu->card->shortname, subs->number + 1);
}
}
int snd_motu_create_midi_devices(struct snd_motu *motu)
{
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;
int err;
/* create midi ports */
err = snd_rawmidi_new(motu->card, motu->card->driver, 0, 1, 1, &rmidi);
if (err < 0)
return err;
snprintf(rmidi->name, sizeof(rmidi->name),
"%s MIDI", motu->card->shortname);
rmidi->private_data = motu;
rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT |
SNDRV_RAWMIDI_INFO_OUTPUT |
SNDRV_RAWMIDI_INFO_DUPLEX;
snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
&capture_ops);
str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT];
set_midi_substream_names(motu, str);
snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
&playback_ops);
str = &rmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT];
set_midi_substream_names(motu, str);
return 0;
}