[Samsung Galaxy Nexus] Walter10h:
By using the GlaDOS kernel and Usb audio recorder ROOT, I was able to listen to music with my USB headset, however I really would like a way to implement it into the kernel or the OS so I can reroute media sound to my headset with other apps.

Here's the source code of the driver... Maybe someone with more knowledge than me will be able to implement it or maybe point me in the right direction.

#ifndef __USBAUDIO_H
#define __USBAUDIO_H
/*
* (Tentative) USB Audio Driver for ALSA
*
* Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
*
*
* 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
*/

/* handling of USB vendor/product ID pairs as 32-bit numbers */
#define USB_ID(vendor, product) (((vendor) << 16) | (product))
#define USB_ID_VENDOR(id) ((id) >> 16)
#define USB_ID_PRODUCT(id) ((u16)(id))

/*
*
*/

struct snd_usb_audio {
int index;
struct usb_device *dev;
struct snd_card *card;
struct usb_interface *pm_intf;
u32 usb_id;
struct mutex shutdown_mutex;
unsigned int shutdown:1;
unsigned int probing:1;
unsigned int autosuspended:1;
unsigned int txfr_quirk:1; /* Subframe boundaries on transfers */

int num_interfaces;
int num_suspended_intf;

struct list_head pcm_list;	/* list of pcm streams */
int pcm_devs;

struct list_head midi_list;	/* list of midi interfaces */

struct list_head mixer_list;	/* list of mixer interfaces */

int setup;	/* from the 'device_setup' module param */
int nrpacks;	/* from the 'nrpacks' module param */
int async_unlink;	/* from the 'async_unlink' module param */

struct usb_host_interface *ctrl_intf;	/* the audio control interface */
};

/*
* Information about devices with broken descriptors
*/

/* special values for .ifnum */
#define QUIRK_NO_INTERFACE -2
#define QUIRK_ANY_INTERFACE -1

enum quirk_type {
QUIRK_IGNORE_INTERFACE,
QUIRK_COMPOSITE,
QUIRK_MIDI_STANDARD_INTERFACE,
QUIRK_MIDI_FIXED_ENDPOINT,
QUIRK_MIDI_YAMAHA,
QUIRK_MIDI_MIDIMAN,
QUIRK_MIDI_NOVATION,
QUIRK_MIDI_RAW_BYTES,
QUIRK_MIDI_EMAGIC,
QUIRK_MIDI_CME,
QUIRK_MIDI_AKAI,
QUIRK_MIDI_US122L,
QUIRK_AUDIO_STANDARD_INTERFACE,
QUIRK_AUDIO_FIXED_ENDPOINT,
QUIRK_AUDIO_EDIROL_UAXX,
QUIRK_AUDIO_ALIGN_TRANSFER,
QUIRK_AUDIO_STANDARD_MIXER,

QUIRK_TYPE_COUNT
};

struct snd_usb_audio_quirk {
const char *vendor_name;
const char *product_name;
int16_t ifnum;
uint16_t type;
const void *data;
};

#define combine_word(s) ((*(s)) | ((unsigned int)(s)[1] << 8))
#define combine_triple(s) (combine_word(s) | ((unsigned int)(s)[2] << 16))
#define combine_quad(s) (combine_triple(s) | ((unsigned int)(s)[3] << 24))

#endif /* __USBAUDIO_H */