ALSA: snd-usb: re-order code

Move code from endpoint.c into a new file called stream.c and rename
functions so that their names actually reflect what they're doing.

This way, endpoint.c will be available to functions that hold all the
endpoint logic.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

7 files changed, 472 insertions, 444 deletions

diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 083501e78f3..5390db00e09 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -12,6 +12,7 @@ snd-usb-audio-objs := 	card.o \
 			pcm.o \
 			proc.o \
 			quirks.o \
+			stream.o \
 			urb.o
 
 snd-usbmidi-lib-objs := midi.o
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 781d9e61adf..a3136afb219 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -68,6 +68,7 @@
 #include "urb.h"
 #include "format.h"
 #include "power.h"
+#include "stream.h"
 
 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
 MODULE_DESCRIPTION("USB Audio");
@@ -185,7 +186,7 @@ static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int int
 		return -EINVAL;
 	}
 
-	if (! snd_usb_parse_audio_endpoints(chip, interface)) {
+	if (! snd_usb_parse_audio_interface(chip, interface)) {
 		usb_set_interface(dev, interface, 0); /* reset the current interface */
 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
 		return -EINVAL;
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 7d46e482375..b3ee7cf243d 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -15,436 +15,3 @@
  *
  */
 
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/usb.h>
-#include <linux/usb/audio.h>
-#include <linux/usb/audio-v2.h>
-
-#include <sound/core.h>
-#include <sound/pcm.h>
-
-#include "usbaudio.h"
-#include "card.h"
-#include "proc.h"
-#include "quirks.h"
-#include "endpoint.h"
-#include "urb.h"
-#include "pcm.h"
-#include "helper.h"
-#include "format.h"
-#include "clock.h"
-
-/*
- * free a substream
- */
-static void free_substream(struct snd_usb_substream *subs)
-{
-	struct list_head *p, *n;
-
-	if (!subs->num_formats)
-		return; /* not initialized */
-	list_for_each_safe(p, n, &subs->fmt_list) {
-		struct audioformat *fp = list_entry(p, struct audioformat, list);
-		kfree(fp->rate_table);
-		kfree(fp);
-	}
-	kfree(subs->rate_list.list);
-}
-
-
-/*
- * free a usb stream instance
- */
-static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
-{
-	free_substream(&stream->substream[0]);
-	free_substream(&stream->substream[1]);
-	list_del(&stream->list);
-	kfree(stream);
-}
-
-static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
-{
-	struct snd_usb_stream *stream = pcm->private_data;
-	if (stream) {
-		stream->pcm = NULL;
-		snd_usb_audio_stream_free(stream);
-	}
-}
-
-
-/*
- * add this endpoint to the chip instance.
- * if a stream with the same endpoint already exists, append to it.
- * if not, create a new pcm stream.
- */
-int snd_usb_add_audio_endpoint(struct snd_usb_audio *chip, int stream, struct audioformat *fp)
-{
-	struct list_head *p;
-	struct snd_usb_stream *as;
-	struct snd_usb_substream *subs;
-	struct snd_pcm *pcm;
-	int err;
-
-	list_for_each(p, &chip->pcm_list) {
-		as = list_entry(p, struct snd_usb_stream, list);
-		if (as->fmt_type != fp->fmt_type)
-			continue;
-		subs = &as->substream[stream];
-		if (!subs->endpoint)
-			continue;
-		if (subs->endpoint == fp->endpoint) {
-			list_add_tail(&fp->list, &subs->fmt_list);
-			subs->num_formats++;
-			subs->formats |= fp->formats;
-			return 0;
-		}
-	}
-	/* look for an empty stream */
-	list_for_each(p, &chip->pcm_list) {
-		as = list_entry(p, struct snd_usb_stream, list);
-		if (as->fmt_type != fp->fmt_type)
-			continue;
-		subs = &as->substream[stream];
-		if (subs->endpoint)
-			continue;
-		err = snd_pcm_new_stream(as->pcm, stream, 1);
-		if (err < 0)
-			return err;
-		snd_usb_init_substream(as, stream, fp);
-		return 0;
-	}
-
-	/* create a new pcm */
-	as = kzalloc(sizeof(*as), GFP_KERNEL);
-	if (!as)
-		return -ENOMEM;
-	as->pcm_index = chip->pcm_devs;
-	as->chip = chip;
-	as->fmt_type = fp->fmt_type;
-	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
-			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
-			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
-			  &pcm);
-	if (err < 0) {
-		kfree(as);
-		return err;
-	}
-	as->pcm = pcm;
-	pcm->private_data = as;
-	pcm->private_free = snd_usb_audio_pcm_free;
-	pcm->info_flags = 0;
-	if (chip->pcm_devs > 0)
-		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
-	else
-		strcpy(pcm->name, "USB Audio");
-
-	snd_usb_init_substream(as, stream, fp);
-
-	list_add(&as->list, &chip->pcm_list);
-	chip->pcm_devs++;
-
-	snd_usb_proc_pcm_format_add(as);
-
-	return 0;
-}
-
-static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
-					 struct usb_host_interface *alts,
-					 int protocol, int iface_no)
-{
-	/* parsed with a v1 header here. that's ok as we only look at the
-	 * header first which is the same for both versions */
-	struct uac_iso_endpoint_descriptor *csep;
-	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
-	int attributes = 0;
-
-	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
-
-	/* Creamware Noah has this descriptor after the 2nd endpoint */
-	if (!csep && altsd->bNumEndpoints >= 2)
-		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
-
-	if (!csep || csep->bLength < 7 ||
-	    csep->bDescriptorSubtype != UAC_EP_GENERAL) {
-		snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
-			   " class specific endpoint descriptor\n",
-			   chip->dev->devnum, iface_no,
-			   altsd->bAlternateSetting);
-		return 0;
-	}
-
-	if (protocol == UAC_VERSION_1) {
-		attributes = csep->bmAttributes;
-	} else {
-		struct uac2_iso_endpoint_descriptor *csep2 =
-			(struct uac2_iso_endpoint_descriptor *) csep;
-
-		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
-
-		/* emulate the endpoint attributes of a v1 device */
-		if (csep2->bmControls & UAC2_CONTROL_PITCH)
-			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
-	}
-
-	return attributes;
-}
-
-static struct uac2_input_terminal_descriptor *
-	snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
-					       int terminal_id)
-{
-	struct uac2_input_terminal_descriptor *term = NULL;
-
-	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
-					       ctrl_iface->extralen,
-					       term, UAC_INPUT_TERMINAL))) {
-		if (term->bTerminalID == terminal_id)
-			return term;
-	}
-
-	return NULL;
-}
-
-static struct uac2_output_terminal_descriptor *
-	snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
-						int terminal_id)
-{
-	struct uac2_output_terminal_descriptor *term = NULL;
-
-	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
-					       ctrl_iface->extralen,
-					       term, UAC_OUTPUT_TERMINAL))) {
-		if (term->bTerminalID == terminal_id)
-			return term;
-	}
-
-	return NULL;
-}
-
-int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
-{
-	struct usb_device *dev;
-	struct usb_interface *iface;
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	int i, altno, err, stream;
-	int format = 0, num_channels = 0;
-	struct audioformat *fp = NULL;
-	int num, protocol, clock = 0;
-	struct uac_format_type_i_continuous_descriptor *fmt;
-
-	dev = chip->dev;
-
-	/* parse the interface's altsettings */
-	iface = usb_ifnum_to_if(dev, iface_no);
-
-	num = iface->num_altsetting;
-
-	/*
-	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
-	 * one misses syncpipe, and does not produce any sound.
-	 */
-	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
-		num = 4;
-
-	for (i = 0; i < num; i++) {
-		alts = &iface->altsetting[i];
-		altsd = get_iface_desc(alts);
-		protocol = altsd->bInterfaceProtocol;
-		/* skip invalid one */
-		if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
-		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
-		    (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
-		     altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC) ||
-		    altsd->bNumEndpoints < 1 ||
-		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
-			continue;
-		/* must be isochronous */
-		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
-		    USB_ENDPOINT_XFER_ISOC)
-			continue;
-		/* check direction */
-		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
-			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-		altno = altsd->bAlternateSetting;
-
-		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
-			continue;
-
-		/* get audio formats */
-		switch (protocol) {
-		default:
-			snd_printdd(KERN_WARNING "%d:%u:%d: unknown interface protocol %#02x, assuming v1\n",
-				    dev->devnum, iface_no, altno, protocol);
-			protocol = UAC_VERSION_1;
-			/* fall through */
-
-		case UAC_VERSION_1: {
-			struct uac1_as_header_descriptor *as =
-				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
-
-			if (!as) {
-				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			if (as->bLength < sizeof(*as)) {
-				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
-			break;
-		}
-
-		case UAC_VERSION_2: {
-			struct uac2_input_terminal_descriptor *input_term;
-			struct uac2_output_terminal_descriptor *output_term;
-			struct uac2_as_header_descriptor *as =
-				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
-
-			if (!as) {
-				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			if (as->bLength < sizeof(*as)) {
-				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			num_channels = as->bNrChannels;
-			format = le32_to_cpu(as->bmFormats);
-
-			/* lookup the terminal associated to this interface
-			 * to extract the clock */
-			input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
-									    as->bTerminalLink);
-			if (input_term) {
-				clock = input_term->bCSourceID;
-				break;
-			}
-
-			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
-									      as->bTerminalLink);
-			if (output_term) {
-				clock = output_term->bCSourceID;
-				break;
-			}
-
-			snd_printk(KERN_ERR "%d:%u:%d : bogus bTerminalLink %d\n",
-				   dev->devnum, iface_no, altno, as->bTerminalLink);
-			continue;
-		}
-		}
-
-		/* get format type */
-		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
-		if (!fmt) {
-			snd_printk(KERN_ERR "%d:%u:%d : no UAC_FORMAT_TYPE desc\n",
-				   dev->devnum, iface_no, altno);
-			continue;
-		}
-		if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8)) ||
-		    ((protocol == UAC_VERSION_2) && (fmt->bLength < 6))) {
-			snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
-				   dev->devnum, iface_no, altno);
-			continue;
-		}
-
-		/*
-		 * Blue Microphones workaround: The last altsetting is identical
-		 * with the previous one, except for a larger packet size, but
-		 * is actually a mislabeled two-channel setting; ignore it.
-		 */
-		if (fmt->bNrChannels == 1 &&
-		    fmt->bSubframeSize == 2 &&
-		    altno == 2 && num == 3 &&
-		    fp && fp->altsetting == 1 && fp->channels == 1 &&
-		    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
-		    protocol == UAC_VERSION_1 &&
-		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
-							fp->maxpacksize * 2)
-			continue;
-
-		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
-		if (! fp) {
-			snd_printk(KERN_ERR "cannot malloc\n");
-			return -ENOMEM;
-		}
-
-		fp->iface = iface_no;
-		fp->altsetting = altno;
-		fp->altset_idx = i;
-		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
-		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
-		fp->datainterval = snd_usb_parse_datainterval(chip, alts);
-		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
-		/* num_channels is only set for v2 interfaces */
-		fp->channels = num_channels;
-		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
-			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
-					* (fp->maxpacksize & 0x7ff);
-		fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
-		fp->clock = clock;
-
-		/* some quirks for attributes here */
-
-		switch (chip->usb_id) {
-		case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
-			/* Optoplay sets the sample rate attribute although
-			 * it seems not supporting it in fact.
-			 */
-			fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
-			break;
-		case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
-		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
-			/* doesn't set the sample rate attribute, but supports it */
-			fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
-			break;
-		case USB_ID(0x0763, 0x2001):  /* M-Audio Quattro USB */
-		case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
-		case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
-		case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
-						an older model 77d:223) */
-		/*
-		 * plantronics headset and Griffin iMic have set adaptive-in
-		 * although it's really not...
-		 */
-			fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
-			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
-				fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
-			else
-				fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
-			break;
-		}
-
-		/* ok, let's parse further... */
-		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
-			kfree(fp->rate_table);
-			kfree(fp);
-			fp = NULL;
-			continue;
-		}
-
-		snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
-		err = snd_usb_add_audio_endpoint(chip, stream, fp);
-		if (err < 0) {
-			kfree(fp->rate_table);
-			kfree(fp);
-			return err;
-		}
-		/* try to set the interface... */
-		usb_set_interface(chip->dev, iface_no, altno);
-		snd_usb_init_pitch(chip, iface_no, alts, fp);
-		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
-	}
-	return 0;
-}
-
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index 64dd0db023b..e5d8a6adf38 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -1,11 +1,4 @@
 #ifndef __USBAUDIO_ENDPOINT_H
 #define __USBAUDIO_ENDPOINT_H
 
-int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip,
-				  int iface_no);
-
-int snd_usb_add_audio_endpoint(struct snd_usb_audio *chip,
-			       int stream,
-			       struct audioformat *fp);
-
 #endif /* __USBAUDIO_ENDPOINT_H */
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index cf61b034002..556edea28b9 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -34,6 +34,7 @@
 #include "endpoint.h"
 #include "pcm.h"
 #include "clock.h"
+#include "stream.h"
 
 /*
  * handle the quirks for the contained interfaces
@@ -106,7 +107,7 @@ static int create_standard_audio_quirk(struct snd_usb_audio *chip,
 
 	alts = &iface->altsetting[0];
 	altsd = get_iface_desc(alts);
-	err = snd_usb_parse_audio_endpoints(chip, altsd->bInterfaceNumber);
+	err = snd_usb_parse_audio_interface(chip, altsd->bInterfaceNumber);
 	if (err < 0) {
 		snd_printk(KERN_ERR "cannot setup if %d: error %d\n",
 			   altsd->bInterfaceNumber, err);
@@ -147,7 +148,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
 
 	stream = (fp->endpoint & USB_DIR_IN)
 		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-	err = snd_usb_add_audio_endpoint(chip, stream, fp);
+	err = snd_usb_add_audio_stream(chip, stream, fp);
 	if (err < 0) {
 		kfree(fp);
 		kfree(rate_table);
@@ -254,7 +255,7 @@ static int create_uaxx_quirk(struct snd_usb_audio *chip,
 
 	stream = (fp->endpoint & USB_DIR_IN)
 		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-	err = snd_usb_add_audio_endpoint(chip, stream, fp);
+	err = snd_usb_add_audio_stream(chip, stream, fp);
 	if (err < 0) {
 		kfree(fp);
 		return err;
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
new file mode 100644
index 00000000000..4688d4c6208
--- /dev/null
+++ b/sound/usb/stream.c
@@ -0,0 +1,453 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/audio-v2.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "proc.h"
+#include "quirks.h"
+#include "endpoint.h"
+#include "urb.h"
+#include "pcm.h"
+#include "helper.h"
+#include "format.h"
+#include "clock.h"
+#include "stream.h"
+
+/*
+ * free a substream
+ */
+static void free_substream(struct snd_usb_substream *subs)
+{
+	struct list_head *p, *n;
+
+	if (!subs->num_formats)
+		return; /* not initialized */
+	list_for_each_safe(p, n, &subs->fmt_list) {
+		struct audioformat *fp = list_entry(p, struct audioformat, list);
+		kfree(fp->rate_table);
+		kfree(fp);
+	}
+	kfree(subs->rate_list.list);
+}
+
+
+/*
+ * free a usb stream instance
+ */
+static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
+{
+	free_substream(&stream->substream[0]);
+	free_substream(&stream->substream[1]);
+	list_del(&stream->list);
+	kfree(stream);
+}
+
+static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
+{
+	struct snd_usb_stream *stream = pcm->private_data;
+	if (stream) {
+		stream->pcm = NULL;
+		snd_usb_audio_stream_free(stream);
+	}
+}
+
+
+/*
+ * add this endpoint to the chip instance.
+ * if a stream with the same endpoint already exists, append to it.
+ * if not, create a new pcm stream.
+ */
+int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
+			     int stream,
+			     struct audioformat *fp)
+{
+	struct list_head *p;
+	struct snd_usb_stream *as;
+	struct snd_usb_substream *subs;
+	struct snd_pcm *pcm;
+	int err;
+
+	list_for_each(p, &chip->pcm_list) {
+		as = list_entry(p, struct snd_usb_stream, list);
+		if (as->fmt_type != fp->fmt_type)
+			continue;
+		subs = &as->substream[stream];
+		if (!subs->endpoint)
+			continue;
+		if (subs->endpoint == fp->endpoint) {
+			list_add_tail(&fp->list, &subs->fmt_list);
+			subs->num_formats++;
+			subs->formats |= fp->formats;
+			return 0;
+		}
+	}
+	/* look for an empty stream */
+	list_for_each(p, &chip->pcm_list) {
+		as = list_entry(p, struct snd_usb_stream, list);
+		if (as->fmt_type != fp->fmt_type)
+			continue;
+		subs = &as->substream[stream];
+		if (subs->endpoint)
+			continue;
+		err = snd_pcm_new_stream(as->pcm, stream, 1);
+		if (err < 0)
+			return err;
+		snd_usb_init_substream(as, stream, fp);
+		return 0;
+	}
+
+	/* create a new pcm */
+	as = kzalloc(sizeof(*as), GFP_KERNEL);
+	if (!as)
+		return -ENOMEM;
+	as->pcm_index = chip->pcm_devs;
+	as->chip = chip;
+	as->fmt_type = fp->fmt_type;
+	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
+			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
+			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
+			  &pcm);
+	if (err < 0) {
+		kfree(as);
+		return err;
+	}
+	as->pcm = pcm;
+	pcm->private_data = as;
+	pcm->private_free = snd_usb_audio_pcm_free;
+	pcm->info_flags = 0;
+	if (chip->pcm_devs > 0)
+		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
+	else
+		strcpy(pcm->name, "USB Audio");
+
+	snd_usb_init_substream(as, stream, fp);
+
+	list_add(&as->list, &chip->pcm_list);
+	chip->pcm_devs++;
+
+	snd_usb_proc_pcm_format_add(as);
+
+	return 0;
+}
+
+static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
+					 struct usb_host_interface *alts,
+					 int protocol, int iface_no)
+{
+	/* parsed with a v1 header here. that's ok as we only look at the
+	 * header first which is the same for both versions */
+	struct uac_iso_endpoint_descriptor *csep;
+	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
+	int attributes = 0;
+
+	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
+
+	/* Creamware Noah has this descriptor after the 2nd endpoint */
+	if (!csep && altsd->bNumEndpoints >= 2)
+		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
+
+	if (!csep || csep->bLength < 7 ||
+	    csep->bDescriptorSubtype != UAC_EP_GENERAL) {
+		snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
+			   " class specific endpoint descriptor\n",
+			   chip->dev->devnum, iface_no,
+			   altsd->bAlternateSetting);
+		return 0;
+	}
+
+	if (protocol == UAC_VERSION_1) {
+		attributes = csep->bmAttributes;
+	} else {
+		struct uac2_iso_endpoint_descriptor *csep2 =
+			(struct uac2_iso_endpoint_descriptor *) csep;
+
+		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
+
+		/* emulate the endpoint attributes of a v1 device */
+		if (csep2->bmControls & UAC2_CONTROL_PITCH)
+			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
+	}
+
+	return attributes;
+}
+
+static struct uac2_input_terminal_descriptor *
+	snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+					       int terminal_id)
+{
+	struct uac2_input_terminal_descriptor *term = NULL;
+
+	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+					       ctrl_iface->extralen,
+					       term, UAC_INPUT_TERMINAL))) {
+		if (term->bTerminalID == terminal_id)
+			return term;
+	}
+
+	return NULL;
+}
+
+static struct uac2_output_terminal_descriptor *
+	snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+						int terminal_id)
+{
+	struct uac2_output_terminal_descriptor *term = NULL;
+
+	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+					       ctrl_iface->extralen,
+					       term, UAC_OUTPUT_TERMINAL))) {
+		if (term->bTerminalID == terminal_id)
+			return term;
+	}
+
+	return NULL;
+}
+
+int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
+{
+	struct usb_device *dev;
+	struct usb_interface *iface;
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	int i, altno, err, stream;
+	int format = 0, num_channels = 0;
+	struct audioformat *fp = NULL;
+	int num, protocol, clock = 0;
+	struct uac_format_type_i_continuous_descriptor *fmt;
+
+	dev = chip->dev;
+
+	/* parse the interface's altsettings */
+	iface = usb_ifnum_to_if(dev, iface_no);
+
+	num = iface->num_altsetting;
+
+	/*
+	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
+	 * one misses syncpipe, and does not produce any sound.
+	 */
+	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
+		num = 4;
+
+	for (i = 0; i < num; i++) {
+		alts = &iface->altsetting[i];
+		altsd = get_iface_desc(alts);
+		protocol = altsd->bInterfaceProtocol;
+		/* skip invalid one */
+		if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
+		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
+		    (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
+		     altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC) ||
+		    altsd->bNumEndpoints < 1 ||
+		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
+			continue;
+		/* must be isochronous */
+		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
+		    USB_ENDPOINT_XFER_ISOC)
+			continue;
+		/* check direction */
+		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
+			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
+		altno = altsd->bAlternateSetting;
+
+		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
+			continue;
+
+		/* get audio formats */
+		switch (protocol) {
+		default:
+			snd_printdd(KERN_WARNING "%d:%u:%d: unknown interface protocol %#02x, assuming v1\n",
+				    dev->devnum, iface_no, altno, protocol);
+			protocol = UAC_VERSION_1;
+			/* fall through */
+
+		case UAC_VERSION_1: {
+			struct uac1_as_header_descriptor *as =
+				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
+
+			if (!as) {
+				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			if (as->bLength < sizeof(*as)) {
+				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
+			break;
+		}
+
+		case UAC_VERSION_2: {
+			struct uac2_input_terminal_descriptor *input_term;
+			struct uac2_output_terminal_descriptor *output_term;
+			struct uac2_as_header_descriptor *as =
+				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
+
+			if (!as) {
+				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			if (as->bLength < sizeof(*as)) {
+				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			num_channels = as->bNrChannels;
+			format = le32_to_cpu(as->bmFormats);
+
+			/* lookup the terminal associated to this interface
+			 * to extract the clock */
+			input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
+									    as->bTerminalLink);
+			if (input_term) {
+				clock = input_term->bCSourceID;
+				break;
+			}
+
+			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
+									      as->bTerminalLink);
+			if (output_term) {
+				clock = output_term->bCSourceID;
+				break;
+			}
+
+			snd_printk(KERN_ERR "%d:%u:%d : bogus bTerminalLink %d\n",
+				   dev->devnum, iface_no, altno, as->bTerminalLink);
+			continue;
+		}
+		}
+
+		/* get format type */
+		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
+		if (!fmt) {
+			snd_printk(KERN_ERR "%d:%u:%d : no UAC_FORMAT_TYPE desc\n",
+				   dev->devnum, iface_no, altno);
+			continue;
+		}
+		if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8)) ||
+		    ((protocol == UAC_VERSION_2) && (fmt->bLength < 6))) {
+			snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
+				   dev->devnum, iface_no, altno);
+			continue;
+		}
+
+		/*
+		 * Blue Microphones workaround: The last altsetting is identical
+		 * with the previous one, except for a larger packet size, but
+		 * is actually a mislabeled two-channel setting; ignore it.
+		 */
+		if (fmt->bNrChannels == 1 &&
+		    fmt->bSubframeSize == 2 &&
+		    altno == 2 && num == 3 &&
+		    fp && fp->altsetting == 1 && fp->channels == 1 &&
+		    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
+		    protocol == UAC_VERSION_1 &&
+		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
+							fp->maxpacksize * 2)
+			continue;
+
+		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
+		if (! fp) {
+			snd_printk(KERN_ERR "cannot malloc\n");
+			return -ENOMEM;
+		}
+
+		fp->iface = iface_no;
+		fp->altsetting = altno;
+		fp->altset_idx = i;
+		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
+		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+		fp->datainterval = snd_usb_parse_datainterval(chip, alts);
+		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+		/* num_channels is only set for v2 interfaces */
+		fp->channels = num_channels;
+		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
+			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
+					* (fp->maxpacksize & 0x7ff);
+		fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
+		fp->clock = clock;
+
+		/* some quirks for attributes here */
+
+		switch (chip->usb_id) {
+		case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
+			/* Optoplay sets the sample rate attribute although
+			 * it seems not supporting it in fact.
+			 */
+			fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
+			break;
+		case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
+		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
+			/* doesn't set the sample rate attribute, but supports it */
+			fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
+			break;
+		case USB_ID(0x0763, 0x2001):  /* M-Audio Quattro USB */
+		case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
+		case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
+		case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
+						an older model 77d:223) */
+		/*
+		 * plantronics headset and Griffin iMic have set adaptive-in
+		 * although it's really not...
+		 */
+			fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
+			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+				fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
+			else
+				fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
+			break;
+		}
+
+		/* ok, let's parse further... */
+		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
+			kfree(fp->rate_table);
+			kfree(fp);
+			fp = NULL;
+			continue;
+		}
+
+		snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
+		err = snd_usb_add_audio_stream(chip, stream, fp);
+		if (err < 0) {
+			kfree(fp->rate_table);
+			kfree(fp);
+			return err;
+		}
+		/* try to set the interface... */
+		usb_set_interface(chip->dev, iface_no, altno);
+		snd_usb_init_pitch(chip, iface_no, alts, fp);
+		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
+	}
+	return 0;
+}
+
diff --git a/sound/usb/stream.h b/sound/usb/stream.h
new file mode 100644
index 00000000000..c97f679fc84
--- /dev/null
+++ b/sound/usb/stream.h
@@ -0,0 +1,12 @@
+#ifndef __USBAUDIO_STREAM_H
+#define __USBAUDIO_STREAM_H
+
+int snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
+				  int iface_no);
+
+int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
+			     int stream,
+			     struct audioformat *fp);
+
+#endif /* __USBAUDIO_STREAM_H */
+