[PATCH 24/29] ALSA: oxfw: Change the way to start stream

[Takashi Sakamoto <o-takashi@sakamocchi.jp>]

In past commit, this driver can keep stream formations for each sampling
rate. So its stream functionality can decide stream formations with given
some parameters.

This commit moves related codes from PCM functionality to stream
functionality. Furthermore, to set stream format correctly, this commit
uses AV/C Stream Format Information command instead of AV/C Input/Output
Plug Signal Format command.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
 sound/firewire/oxfw/oxfw-pcm.c    |  38 ++---------
 sound/firewire/oxfw/oxfw-stream.c | 139 +++++++++++++++++++++++++++++++++++---
 sound/firewire/oxfw/oxfw.h        |   3 +-
 3 files changed, 137 insertions(+), 43 deletions(-)

diff --git a/sound/firewire/oxfw/oxfw-pcm.c b/sound/firewire/oxfw/oxfw-pcm.c
index 727d281..ab5991a 100644
--- a/sound/firewire/oxfw/oxfw-pcm.c
+++ b/sound/firewire/oxfw/oxfw-pcm.c
@@ -166,36 +166,10 @@ static int pcm_hw_params(struct snd_pcm_substream *substream,
 			 struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
-	int err;
-
-	snd_oxfw_stream_stop_simplex(oxfw);
-
-	err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
-					       params_buffer_bytes(hw_params));
-	if (err < 0)
-		goto error;
-
-	amdtp_stream_set_parameters(&oxfw->rx_stream,
-				    params_rate(hw_params),
-				    params_channels(hw_params),
-				    0);
 
-	amdtp_stream_set_pcm_format(&oxfw->rx_stream,
-				    params_format(hw_params));
-
-	err = avc_general_set_sig_fmt(oxfw->unit, params_rate(hw_params),
-				      AVC_GENERAL_PLUG_DIR_IN, 0);
-	if (err < 0) {
-		dev_err(&oxfw->unit->device, "failed to set sample rate\n");
-		goto err_buffer;
-	}
-
-	return 0;
-
-err_buffer:
-	snd_pcm_lib_free_vmalloc_buffer(substream);
-error:
-	return err;
+	amdtp_stream_set_pcm_format(&oxfw->rx_stream, params_format(hw_params));
+	return snd_pcm_lib_alloc_vmalloc_buffer(substream,
+						params_buffer_bytes(hw_params));
 }
 
 static int pcm_hw_free(struct snd_pcm_substream *substream)
@@ -210,11 +184,11 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 static int pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_oxfw *oxfw = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;
 
-	snd_oxfw_stream_stop_simplex(oxfw);
-
-	err = snd_oxfw_stream_start_simplex(oxfw);
+	err = snd_oxfw_stream_start_simplex(oxfw, runtime->rate,
+					    runtime->channels);
 	if (err < 0)
 		goto end;
 
diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c
index dd905fe..e3ba398 100644
--- a/sound/firewire/oxfw/oxfw-stream.c
+++ b/sound/firewire/oxfw/oxfw-stream.c
@@ -7,8 +7,10 @@
  */
 
 #include "oxfw.h"
+#include <linux/delay.h>
 
 #define AVC_GENERIC_FRAME_MAXIMUM_BYTES	512
+#define CALLBACK_TIMEOUT	200
 
 /*
  * According to datasheet of Oxford Semiconductor:
@@ -37,6 +39,47 @@ static const unsigned int avc_stream_rate_table[] = {
 	[5] = 0x07,
 };
 
+static int set_stream_format(struct snd_oxfw *oxfw, struct amdtp_stream *s,
+			     unsigned int rate, unsigned int pcm_channels)
+{
+	u8 **formats;
+	struct snd_oxfw_stream_formation formation;
+	enum avc_general_plug_dir dir;
+	unsigned int i, err, len;
+
+	formats = oxfw->rx_stream_formats;
+	dir = AVC_GENERAL_PLUG_DIR_IN;
+
+	/* Seek stream format for requirements. */
+	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+		err = snd_oxfw_stream_parse_format(formats[i], &formation);
+		if (err < 0)
+			return err;
+
+		if ((formation.rate == rate) && (formation.pcm == pcm_channels))
+			break;
+	}
+	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
+		return -EINVAL;
+
+	/* If assumed, just change rate. */
+	if (oxfw->assumed)
+		return avc_general_set_sig_fmt(oxfw->unit, rate,
+					       AVC_GENERAL_PLUG_DIR_IN, 0);
+
+	/* Calculate format length. */
+	len = 5 + formats[i][4] * 2;
+
+	err = avc_stream_set_format(oxfw->unit, dir, 0, formats[i], len);
+	if (err < 0)
+		return err;
+
+	/* Some immediate requests just after changing format causes freezing. */
+	msleep(100);
+
+	return 0;
+}
+
 int snd_oxfw_stream_init_simplex(struct snd_oxfw *oxfw)
 {
 	int err;
@@ -63,28 +106,104 @@ static void stop_stream(struct snd_oxfw *oxfw)
 	cmp_connection_break(&oxfw->in_conn);
 }
 
-int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw)
+static int start_stream(struct snd_oxfw *oxfw, unsigned int rate,
+			unsigned int pcm_channels)
 {
+	u8 **formats;
+	struct cmp_connection *conn;
+	struct snd_oxfw_stream_formation formation;
+	unsigned int i, midi_ports;
+	struct amdtp_stream *stream;
+	int err;
+
+	stream = &oxfw->rx_stream;
+	formats = oxfw->rx_stream_formats;
+	conn = &oxfw->in_conn;
+
+	/* Get stream formation */
+	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
+		if (formats[i] == NULL)
+			break;
+
+		err = snd_oxfw_stream_parse_format(formats[i], &formation);
+		if (err < 0)
+			goto end;
+		if (rate != formation.rate)
+			continue;
+		if (pcm_channels == 0 ||  pcm_channels == formation.pcm)
+			break;
+	}
+	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES) {
+		err = -EINVAL;
+		goto end;
+	}
+
+	pcm_channels = formation.pcm;
+	midi_ports = DIV_ROUND_UP(formation.midi, 8);
+
+	/* The stream should have one pcm channels at least */
+	if (pcm_channels == 0) {
+		err = -EINVAL;
+		goto end;
+	}
+	amdtp_stream_set_parameters(stream, rate, pcm_channels, midi_ports);
+
+	err = cmp_connection_establish(conn,
+				       amdtp_stream_get_max_payload(stream));
+	if (err < 0)
+		goto end;
+
+	err = amdtp_stream_start(stream,
+				 conn->resources.channel,
+				 conn->speed);
+	if (err < 0) {
+		cmp_connection_break(conn);
+		goto end;
+	}
+
+	/* Wait first packet */
+	err = amdtp_stream_wait_callback(stream, CALLBACK_TIMEOUT);
+	if (err < 0)
+		stop_stream(oxfw);
+end:
+	return err;
+}
+
+int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw, unsigned int rate,
+				  unsigned int pcm_channels)
+{
+	struct snd_oxfw_stream_formation formation;
 	int err = 0;
 
 	mutex_lock(&oxfw->mutex);
 
+	/* packet queueing error */
 	if (amdtp_streaming_error(&oxfw->rx_stream))
 		stop_stream(oxfw);
 
-	if (amdtp_stream_running(&oxfw->rx_stream))
-		goto end;
-
-	err = cmp_connection_establish(&oxfw->in_conn,
-			amdtp_stream_get_max_payload(&oxfw->rx_stream));
+	err = snd_oxfw_stream_get_current_formation(oxfw,
+						    AVC_GENERAL_PLUG_DIR_IN,
+						    &formation);
 	if (err < 0)
 		goto end;
 
-	err = amdtp_stream_start(&oxfw->rx_stream,
-				 oxfw->in_conn.resources.channel,
-				 oxfw->in_conn.speed);
-	if (err < 0)
+	if ((formation.rate != rate) || (formation.pcm != pcm_channels)) {
 		stop_stream(oxfw);
+
+		/* arrange sampling rate */
+		err = set_stream_format(oxfw, &oxfw->rx_stream, rate,
+					pcm_channels);
+		if (err < 0) {
+			dev_err(&oxfw->unit->device,
+				"fail to set stream format: %d\n", err);
+			goto end;
+		}
+	}
+
+	err = start_stream(oxfw, rate, pcm_channels);
+	if (err < 0)
+		dev_err(&oxfw->unit->device,
+			"fail to start stream: %d\n", err);
 end:
 	mutex_unlock(&oxfw->mutex);
 	return err;
diff --git a/sound/firewire/oxfw/oxfw.h b/sound/firewire/oxfw/oxfw.h
index 6bc2ac3..433e0c0 100644
--- a/sound/firewire/oxfw/oxfw.h
+++ b/sound/firewire/oxfw/oxfw.h
@@ -88,7 +88,8 @@ int avc_general_inquiry_sig_fmt(struct fw_unit *unit, unsigned int rate,
 				unsigned short pid);
 
 int snd_oxfw_stream_init_simplex(struct snd_oxfw *oxfw);
-int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw);
+int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw, unsigned int rate,
+				  unsigned int pcm_channels);
 void snd_oxfw_stream_stop_simplex(struct snd_oxfw *oxfw);
 void snd_oxfw_stream_destroy_simplex(struct snd_oxfw *oxfw);
 void snd_oxfw_stream_update_simplex(struct snd_oxfw *oxfw);
-- 
1.9.1