1. 根目录:
2. sound
3. usb
4. usbaudio.h

#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 mutex;
	unsigned int autosuspended:1;	
	atomic_t active;
	atomic_t shutdown;
	atomic_t usage_count;
	wait_queue_head_t shutdown_wait;
	unsigned int txfr_quirk:1; /* Subframe boundaries on transfers */
	unsigned int tx_length_quirk:1; /* Put length specifier in transfers */
	
	int num_interfaces;
	int num_suspended_intf;

	struct list_head pcm_list;	/* list of pcm streams */
	struct list_head ep_list;	/* list of audio-related endpoints */
	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 */
	bool autoclock;			/* from the 'autoclock' module param */

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

#define usb_audio_err(chip, fmt, args...) \
	dev_err(&(chip)->dev->dev, fmt, ##args)
#define usb_audio_warn(chip, fmt, args...) \
	dev_warn(&(chip)->dev->dev, fmt, ##args)
#define usb_audio_info(chip, fmt, args...) \
	dev_info(&(chip)->dev->dev, fmt, ##args)
#define usb_audio_dbg(chip, fmt, args...) \
	dev_dbg(&(chip)->dev->dev, fmt, ##args)

/*
 * 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_AUTODETECT,
	QUIRK_MIDI_STANDARD_INTERFACE,
	QUIRK_MIDI_FIXED_ENDPOINT,
	QUIRK_MIDI_YAMAHA,
	QUIRK_MIDI_ROLAND,
	QUIRK_MIDI_MIDIMAN,
	QUIRK_MIDI_NOVATION,
	QUIRK_MIDI_RAW_BYTES,
	QUIRK_MIDI_EMAGIC,
	QUIRK_MIDI_CME,
	QUIRK_MIDI_AKAI,
	QUIRK_MIDI_US122L,
	QUIRK_MIDI_FTDI,
	QUIRK_MIDI_CH345,
	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))

int snd_usb_lock_shutdown(struct snd_usb_audio *chip);
void snd_usb_unlock_shutdown(struct snd_usb_audio *chip);

#endif /* __USBAUDIO_H */