ALSA: firewire-tascam: add hwdep interface

This commit adds hwdep interface so as the other IEEE 1394 sound devices
has.

This interface is designed for mixer/control applications. 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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 14 insertions, 3 deletions

diff --git a/sound/firewire/tascam/tascam-pcm.c b/sound/firewire/tascam/tascam-pcm.c
index 696b371e3c44..380d3db969a5 100644
--- a/sound/firewire/tascam/tascam-pcm.c
+++ b/sound/firewire/tascam/tascam-pcm.c
@@ -72,9 +72,13 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	unsigned int rate;
 	int err;
 
+	err = snd_tscm_stream_lock_try(tscm);
+	if (err < 0)
+		goto end;
+
 	err = pcm_init_hw_params(tscm, substream);
 	if (err < 0)
-		return err;
+		goto err_locked;
 
 	err = snd_tscm_stream_get_clock(tscm, &clock);
 	if (clock != SND_TSCM_CLOCK_INTERNAL ||
@@ -82,18 +86,25 @@ static int pcm_open(struct snd_pcm_substream *substream)
 	    amdtp_stream_pcm_running(&tscm->tx_stream)) {
 		err = snd_tscm_stream_get_rate(tscm, &rate);
 		if (err < 0)
-			return err;
+			goto err_locked;
 		substream->runtime->hw.rate_min = rate;
 		substream->runtime->hw.rate_max = rate;
 	}
 
 	snd_pcm_set_sync(substream);
-
+end:
+	return err;
+err_locked:
+	snd_tscm_stream_lock_release(tscm);
 	return err;
 }
 
 static int pcm_close(struct snd_pcm_substream *substream)
 {
+	struct snd_tscm *tscm = substream->private_data;
+
+	snd_tscm_stream_lock_release(tscm);
+
 	return 0;
 }