ALSA: firewire-lib: add AMDTP domain structure to handle several isoc contexts

This commit adds 'struct amdtp_domain' structure. This structure
has list of instance of AMDTP stream to handle a couple of
isochronous contexts.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -1136,3 +1136,25 @@ void amdtp_stream_pcm_abort(struct amdtp_stream *s)
 		snd_pcm_stop_xrun(pcm);
 }
 EXPORT_SYMBOL(amdtp_stream_pcm_abort);
+
+/**
+ * amdtp_domain_init - initialize an AMDTP domain structure
+ * @d: the AMDTP domain to initialize.
+ */
+int amdtp_domain_init(struct amdtp_domain *d)
+{
+	INIT_LIST_HEAD(&d->streams);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(amdtp_domain_init);
+
+/**
+ * amdtp_domain_destroy - destroy an AMDTP domain structure
+ * @d: the AMDTP domain to destroy.
+ */
+void amdtp_domain_destroy(struct amdtp_domain *d)
+{
+	WARN_ON(!list_empty(&d->streams));
+}
+EXPORT_SYMBOL_GPL(amdtp_domain_destroy);

sound/firewire/amdtp-stream.h

@@ -267,4 +267,11 @@ static inline bool amdtp_stream_wait_callback(struct amdtp_stream *s,
 				  msecs_to_jiffies(timeout)) > 0;
 }
 
+struct amdtp_domain {
+	struct list_head streams;
+};
+
+int amdtp_domain_init(struct amdtp_domain *d);
+void amdtp_domain_destroy(struct amdtp_domain *d);
+
 #endif