[RFC,34/37] ALSA: firewire-motu: add proc node to show the status of internal clock

Commit Message

Takashi Sakamoto July 11, 2015, 2:12 p.m. UTC

This commit adds a proc node for debugging purpose.

Signed-off-by: Takashi Sakamoto <[e-mail]>
---
 sound/firewire/motu/Makefile    |  3 +-
 sound/firewire/motu/motu-proc.c | 73 +++++++++++++++++++++++++++++++++++++++++
 sound/firewire/motu/motu.c      |  2 ++
 sound/firewire/motu/motu.h      |  3 ++
 4 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 sound/firewire/motu/motu-proc.c

Comments

Jonathan Woithe July 13, 2015, 11:28 a.m. UTC | #1

On Sat, Jul 11, 2015 at 11:12:45PM +0900, Takashi Sakamoto wrote:
> This commit adds a proc node for debugging purpose.
> :
> +static void proc_read_clock(struct snd_info_entry *entry,
> +			    struct snd_info_buffer *buffer)
> +{
> +
> +	struct snd_motu *motu = entry->private_data;
> +	unsigned int rate;
> +	enum snd_motu_clock src;
> +
> +	if (snd_motu_stream_get_rate(motu, &rate) < 0)
> +		return;
> +	if (snd_motu_stream_get_clock(motu, &src) < 0)
> +		return;
> +
> +	snd_iprintf(buffer, "Rate:\t%d\n", rate);
> +	snd_iprintf(buffer, "Source:\t%s\n", clock_names[src]);
> +}

Is it necessary to define a proc node for this information?  It is trivial
to obtain the status of MOTU devices directly from the device regardless of
the state of the streaming system.  In fact, while the above code seems to
be linked to a running stream, the concept of the device clock persists even
when no streams are running.  Or is the intent here to verify the internal
state of any running ALSA stream structures rather than the physical device
itself?

Regards
  jonathan

Patch

diff --git a/sound/firewire/motu/Makefile b/sound/firewire/motu/Makefile
index e41c693..de6ca3b 100644
--- a/sound/firewire/motu/Makefile
+++ b/sound/firewire/motu/Makefile
@@ -1,2 +1,3 @@ 
-snd-firewire-motu-objs := amdtp-motu.o motu-stream.o motu-transaction.o motu.o
+snd-firewire-motu-objs := amdtp-motu.o motu-stream.o motu-transaction.o \
+			  motu-proc.o motu.o
 obj-m += snd-firewire-motu.o
diff --git a/sound/firewire/motu/motu-proc.c b/sound/firewire/motu/motu-proc.c
new file mode 100644
index 0000000..bc84537
--- /dev/null
+++ b/sound/firewire/motu/motu-proc.c
@@ -0,0 +1,73 @@ 
+/*
+ * motu-proc.c - a part of driver for MOTU FireWire series
+ *
+ * Copyright (c) 2015 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "./motu.h"
+
+static const char *const clock_names[] = {
+	[SND_MOTU_CLOCK_INTERNAL] = "internal",
+	[SND_MOTU_CLOCK_OPT] = "optical interface with ADAT or S/PDIF",
+	[SND_MOTU_CLOCK_SPDIF_COAX] = "coaxial interface with S/PDIF",
+	[SND_MOTU_CLOCK_SPH] = "SMPTE in SPH",
+	[SND_MOTU_CLOCK_ADAT_DSUB] = "D-Sub interface with ADAT",
+	[SND_MOTU_CLOCK_AESEBU_XLR] = "XLR interface with AES/EBU",
+	[SND_MOTU_CLOCK_WORD_BNC] = "BNC interface with Word",
+};
+
+static void proc_read_clock(struct snd_info_entry *entry,
+			    struct snd_info_buffer *buffer)
+{
+
+	struct snd_motu *motu = entry->private_data;
+	unsigned int rate;
+	enum snd_motu_clock src;
+
+	if (snd_motu_stream_get_rate(motu, &rate) < 0)
+		return;
+	if (snd_motu_stream_get_clock(motu, &src) < 0)
+		return;
+
+	snd_iprintf(buffer, "Rate:\t%d\n", rate);
+	snd_iprintf(buffer, "Source:\t%s\n", clock_names[src]);
+}
+
+static void add_node(struct snd_motu *motu, struct snd_info_entry *root,
+		     const char *name,
+		     void (*op)(struct snd_info_entry *e,
+				struct snd_info_buffer *b))
+{
+	struct snd_info_entry *entry;
+
+	entry = snd_info_create_card_entry(motu->card, name, root);
+	if (entry == NULL)
+		return;
+
+	snd_info_set_text_ops(entry, motu, op);
+	if (snd_info_register(entry) < 0)
+		snd_info_free_entry(entry);
+}
+
+void snd_motu_proc_init(struct snd_motu *motu)
+{
+	struct snd_info_entry *root;
+
+	/*
+	 * All nodes are automatically removed at snd_card_disconnect(),
+	 * by following to link list.
+	 */
+	root = snd_info_create_card_entry(motu->card, "firewire",
+					  motu->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;
+	}
+
+	add_node(motu, root, "clock", proc_read_clock);
+}
diff --git a/sound/firewire/motu/motu.c b/sound/firewire/motu/motu.c
index 3c7a51f..5717854 100644
--- a/sound/firewire/motu/motu.c
+++ b/sound/firewire/motu/motu.c
@@ -76,6 +76,8 @@  static int motu_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 	if (err < 0)
 		goto error;
 
+	snd_motu_proc_init(motu);
+
 	err = snd_card_register(card);
 	if (err < 0)
 		goto error;
diff --git a/sound/firewire/motu/motu.h b/sound/firewire/motu/motu.h
index 1597e99..8486dd8 100644
--- a/sound/firewire/motu/motu.h
+++ b/sound/firewire/motu/motu.h
@@ -23,6 +23,7 @@ 
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/rawmidi.h>
+#include <sound/info.h>
 
 #include "../amdtp-stream.h"
 #include "../iso-resources.h"
@@ -105,4 +106,6 @@  int snd_motu_transaction_register(struct snd_motu *motu);
 int snd_motu_transaction_reregister(struct snd_motu *motu);
 void snd_motu_transaction_unregister(struct snd_motu *motu);
 
+void snd_motu_proc_init(struct snd_motu *motu);
+
 #endif