diff --git a/sound/firewire/fireface/ff.h b/sound/firewire/fireface/ff.h
index 269fa259d5a7..7be0ea4aaa4b 100644
--- a/sound/firewire/fireface/ff.h
+++ b/sound/firewire/fireface/ff.h
@@ -19,11 +19,13 @@
 #include <linux/compat.h>
 
 #include <sound/core.h>
+#include <sound/info.h>
 
 #include "../lib.h"
 
 #define SND_FF_STREAM_MODES		3
 
+struct snd_ff_protocol;
 struct snd_ff_spec {
 	const char *const name;
 
@@ -32,6 +34,8 @@ struct snd_ff_spec {
 
 	unsigned int midi_in_ports;
 	unsigned int midi_out_ports;
+
+	struct snd_ff_protocol *protocol;
 };
 
 struct snd_ff {
@@ -44,4 +48,31 @@ struct snd_ff {
 
 	const struct snd_ff_spec *spec;
 };
+
+enum snd_ff_clock_src {
+	SND_FF_CLOCK_SRC_INTERNAL,
+	SND_FF_CLOCK_SRC_SPDIF,
+	SND_FF_CLOCK_SRC_ADAT,
+	SND_FF_CLOCK_SRC_WORD,
+	SND_FF_CLOCK_SRC_LTC,
+	/* TODO: perhaps ADAT2 and TCO exists. */
+};
+
+struct snd_ff_protocol {
+	int (*get_clock)(struct snd_ff *ff, unsigned int *rate,
+			 enum snd_ff_clock_src *src);
+	int (*begin_session)(struct snd_ff *ff, unsigned int rate);
+	void (*finish_session)(struct snd_ff *ff);
+	int (*switch_fetching_mode)(struct snd_ff *ff, bool enable);
+
+	void (*dump_sync_status)(struct snd_ff *ff,
+				 struct snd_info_buffer *buffer);
+	void (*dump_clock_config)(struct snd_ff *ff,
+				  struct snd_info_buffer *buffer);
+
+	u64 midi_high_addr_reg;
+	u64 midi_rx_port_0_reg;
+	u64 midi_rx_port_1_reg;
+};
+
 #endif