ALSA: oxfw: Add hwdep interface

This interface is designed for mixer/control application. By using this
interface, an application can get information about firewire node, can
lock/unlock kernel streaming and can get notification at starting/stopping
kernel streaming.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/sound/firewire/oxfw/oxfw-midi.c b/sound/firewire/oxfw/oxfw-midi.c
index 334b11d1a422..540a30338516 100644
--- a/sound/firewire/oxfw/oxfw-midi.c
+++ b/sound/firewire/oxfw/oxfw-midi.c
@@ -13,6 +13,10 @@ static int midi_capture_open(struct snd_rawmidi_substream *substream)
 	struct snd_oxfw *oxfw = substream->rmidi->private_data;
 	int err;
 
+	err = snd_oxfw_stream_lock_try(oxfw);
+	if (err < 0)
+		return err;
+
 	mutex_lock(&oxfw->mutex);
 
 	oxfw->capture_substreams++;
@@ -20,6 +24,9 @@ static int midi_capture_open(struct snd_rawmidi_substream *substream)
 
 	mutex_unlock(&oxfw->mutex);
 
+	if (err < 0)
+		snd_oxfw_stream_lock_release(oxfw);
+
 	return err;
 }
 
@@ -28,6 +35,10 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream)
 	struct snd_oxfw *oxfw = substream->rmidi->private_data;
 	int err;
 
+	err = snd_oxfw_stream_lock_try(oxfw);
+	if (err < 0)
+		return err;
+
 	mutex_lock(&oxfw->mutex);
 
 	oxfw->playback_substreams++;
@@ -35,6 +46,9 @@ static int midi_playback_open(struct snd_rawmidi_substream *substream)
 
 	mutex_unlock(&oxfw->mutex);
 
+	if (err < 0)
+		snd_oxfw_stream_lock_release(oxfw);
+
 	return err;
 }
 
@@ -49,6 +63,7 @@ static int midi_capture_close(struct snd_rawmidi_substream *substream)
 
 	mutex_unlock(&oxfw->mutex);
 
+	snd_oxfw_stream_lock_release(oxfw);
 	return 0;
 }
 
@@ -63,6 +78,7 @@ static int midi_playback_close(struct snd_rawmidi_substream *substream)
 
 	mutex_unlock(&oxfw->mutex);
 
+	snd_oxfw_stream_lock_release(oxfw);
 	return 0;
 }