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>
diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
index a38b3c3..b77cf80 100644
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -644,3 +644,42 @@
end:
return err;
}
+
+void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
+{
+ oxfw->dev_lock_changed = true;
+ wake_up(&oxfw->hwdep_wait);
+}
+
+int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
+{
+ int err;
+
+ spin_lock_irq(&oxfw->lock);
+
+ /* user land lock this */
+ if (oxfw->dev_lock_count < 0) {
+ err = -EBUSY;
+ goto end;
+ }
+
+ /* this is the first time */
+ if (oxfw->dev_lock_count++ == 0)
+ snd_oxfw_stream_lock_changed(oxfw);
+ err = 0;
+end:
+ spin_unlock_irq(&oxfw->lock);
+ return err;
+}
+
+void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
+{
+ spin_lock_irq(&oxfw->lock);
+
+ if (WARN_ON(oxfw->dev_lock_count <= 0))
+ goto end;
+ if (--oxfw->dev_lock_count == 0)
+ snd_oxfw_stream_lock_changed(oxfw);
+end:
+ spin_unlock_irq(&oxfw->lock);
+}