diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
new file mode 100644
index 0000000..3f53dee
--- /dev/null
+++ b/sound/usb/endpoint.c
@@ -0,0 +1,358 @@
+/*
+ *   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/usb.h>
+#include <linux/usb/audio.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"
+
+/*
+ * 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 |= 1ULL << fp->format;
+			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;
+}
+
+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;
+	unsigned char *fmt, *csep;
+	int num, protocol;
+
+	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) {
+		case UAC_VERSION_1: {
+			struct uac_as_header_descriptor_v1 *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 uac_as_header_descriptor_v2 *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);
+
+			break;
+		}
+
+		default:
+			snd_printk(KERN_ERR "%d:%u:%d : unknown interface protocol %04x\n",
+				   dev->devnum, iface_no, altno, protocol);
+			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[0] < 8)) ||
+		    ((protocol == UAC_VERSION_2) && (fmt[0] != 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[4] == 1 && fmt[5] == 2 && altno == 2 && num == 3 &&
+		    fp && fp->altsetting == 1 && fp->channels == 1 &&
+		    fp->format == SNDRV_PCM_FORMAT_S16_LE &&
+		    protocol == UAC_VERSION_1 &&
+		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
+							fp->maxpacksize * 2)
+			continue;
+
+		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[0] < 7 || csep[2] != UAC_EP_GENERAL) {
+			snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
+				   " class specific endpoint descriptor\n",
+				   dev->devnum, iface_no, altno);
+			csep = NULL;
+		}
+
+		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 = csep ? csep[3] : 0;
+
+		/* 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(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);
+			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->dev, iface_no, alts, fp);
+		snd_usb_init_sample_rate(chip->dev, iface_no, alts, fp, fp->rate_max);
+	}
+	return 0;
+}
+