diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 083501e..5390db0 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -12,6 +12,7 @@
 			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 781d9e6..a3136af 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 @@
 		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 7d46e48..b3ee7cf 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 64dd0db..e5d8a6a 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 cf61b03..556edea 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 @@
 
 	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 @@
 
 	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 @@
 
 	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 0000000..4688d4c
--- /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 0000000..c97f679
--- /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 */
+