--- /dev/null
+/*
+ * 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);
+       }
+}
 
 
 #include <sound/core.h>
 #include <sound/initval.h>
+#include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 
        SND_DG00X_CLOCK_COUNT,
 };
 
+enum snd_dg00x_optical_mode {
+       SND_DG00X_OPT_IFACE_MODE_ADAT = 0,
+       SND_DG00X_OPT_IFACE_MODE_SPDIF,
+       SND_DG00X_OPT_IFACE_MODE_COUNT,
+};
+
 int amdtp_dot_init(struct amdtp_stream *s, struct fw_unit *unit,
                   enum amdtp_stream_direction dir);
 int amdtp_dot_set_parameters(struct amdtp_stream *s, unsigned int rate,
 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