diff --git a/sound/firewire/digi00x/Makefile b/sound/firewire/digi00x/Makefile
index b7c783d..6c9bc37 100644
--- a/sound/firewire/digi00x/Makefile
+++ b/sound/firewire/digi00x/Makefile
@@ -1,2 +1,3 @@
-snd-firewire-digi00x-objs := amdtp-dot.o digi00x-stream.o digi00x.o
+snd-firewire-digi00x-objs := amdtp-dot.o digi00x-stream.o digi00x-proc.o \
+			     digi00x.o
 obj-m += snd-firewire-digi00x.o
diff --git a/sound/firewire/digi00x/digi00x-proc.c b/sound/firewire/digi00x/digi00x-proc.c
new file mode 100644
index 0000000..280d621
--- /dev/null
+++ b/sound/firewire/digi00x/digi00x-proc.c
@@ -0,0 +1,99 @@
+/*
+ * digi00x-proc.c - a part of driver for Digidesign Digi 002/003 family
+ *
+ * Copyright (c) 2014-2015 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "./digi00x.h"
+
+static int get_optical_iface_mode(struct snd_dg00x *dg00x,
+				  enum snd_dg00x_optical_mode *mode)
+{
+	__be32 data;
+	int err;
+
+	err = snd_fw_transaction(dg00x->unit, TCODE_READ_QUADLET_REQUEST,
+				 DG00X_ADDR_BASE + DG00X_OFFSET_OPT_IFACE_MODE,
+				 &data, sizeof(data), 0);
+	if (err >= 0)
+		*mode = be32_to_cpu(data) & 0x01;
+
+	return err;
+}
+
+static void proc_read_clock(struct snd_info_entry *entry,
+			    struct snd_info_buffer *buf)
+{
+	static const char *const source_name[] = {
+		[SND_DG00X_CLOCK_INTERNAL] = "internal",
+		[SND_DG00X_CLOCK_SPDIF] = "s/pdif",
+		[SND_DG00X_CLOCK_ADAT] = "adat",
+		[SND_DG00X_CLOCK_WORD] = "word clock",
+	};
+	static const char *const optical_name[] = {
+		[SND_DG00X_OPT_IFACE_MODE_ADAT] = "adat",
+		[SND_DG00X_OPT_IFACE_MODE_SPDIF] = "s/pdif",
+	};
+	struct snd_dg00x *dg00x = entry->private_data;
+	enum snd_dg00x_optical_mode mode;
+	unsigned int rate;
+	enum snd_dg00x_clock clock;
+	bool detect;
+
+	if (get_optical_iface_mode(dg00x, &mode) < 0)
+		return;
+	if (snd_dg00x_stream_get_local_rate(dg00x, &rate) < 0)
+		return;
+	if (snd_dg00x_stream_get_clock(dg00x, &clock) < 0)
+		return;
+
+	snd_iprintf(buf, "Optical mode: %s\n", optical_name[mode]);
+	snd_iprintf(buf, "Sampling Rate: %d\n", rate);
+	snd_iprintf(buf, "Clock Source: %s\n", source_name[clock]);
+
+	if (clock == SND_DG00X_CLOCK_INTERNAL)
+		return;
+
+	if (snd_dg00x_stream_check_external_clock(dg00x, &detect) < 0)
+		return;
+	snd_iprintf(buf, "External source: %s\n", detect ? "detected" : "not");
+	if (!detect)
+		return;
+
+	if (snd_dg00x_stream_get_external_rate(dg00x, &rate) >= 0)
+		snd_iprintf(buf, "External sampling rate: %d\n", rate);
+}
+
+void snd_dg00x_proc_init(struct snd_dg00x *dg00x)
+{
+	struct snd_info_entry *root, *entry;
+
+	/*
+	 * All nodes are automatically removed at snd_card_disconnect(),
+	 * by following to link list.
+	 */
+	root = snd_info_create_card_entry(dg00x->card, "firewire",
+					  dg00x->card->proc_root);
+	if (root == NULL)
+		return;
+
+	root->mode = S_IFDIR | S_IRUGO | S_IXUGO;
+	if (snd_info_register(root) < 0) {
+		snd_info_free_entry(root);
+		return;
+	}
+
+	entry = snd_info_create_card_entry(dg00x->card, "clock", root);
+	if (entry == NULL) {
+		snd_info_free_entry(root);
+		return;
+	}
+
+	snd_info_set_text_ops(entry, dg00x, proc_read_clock);
+	if (snd_info_register(entry) < 0) {
+		snd_info_free_entry(entry);
+		snd_info_free_entry(root);
+	}
+}
diff --git a/sound/firewire/digi00x/digi00x.c b/sound/firewire/digi00x/digi00x.c
index 2c517ec..130f569 100644
--- a/sound/firewire/digi00x/digi00x.c
+++ b/sound/firewire/digi00x/digi00x.c
@@ -83,6 +83,8 @@ static int snd_dg00x_probe(struct fw_unit *unit,
 	if (err < 0)
 		goto error;
 
+	snd_dg00x_proc_init(dg00x);
+
 	err = snd_card_register(card);
 	if (err < 0)
 		goto error;
diff --git a/sound/firewire/digi00x/digi00x.h b/sound/firewire/digi00x/digi00x.h
index dd9b39a..da6950e 100644
--- a/sound/firewire/digi00x/digi00x.h
+++ b/sound/firewire/digi00x/digi00x.h
@@ -19,6 +19,7 @@
 
 #include <sound/core.h>
 #include <sound/initval.h>
+#include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/rawmidi.h>
@@ -119,4 +120,5 @@ void snd_dg00x_stream_stop_duplex(struct snd_dg00x *dg00x);
 void snd_dg00x_stream_update_duplex(struct snd_dg00x *dg00x);
 void snd_dg00x_stream_destroy_duplex(struct snd_dg00x *dg00x);
 
+void snd_dg00x_proc_init(struct snd_dg00x *dg00x);
 #endif
