sound/usb/card.c - kernel/msm-4.19 - Gitiles

 /*
  *   (Tentative) USB Audio Driver for ALSA
  *
  *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
  *
  *   Many codes borrowed from audio.c by
  *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
  *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
  *
  *
  *   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
  *
  *
  *  NOTES:
  *
  *   - the linked URBs would be preferred but not used so far because of
  *     the instability of unlinking.
  *   - type II is not supported properly.  there is no device which supports
  *     this type *correctly*.  SB extigy looks as if it supports, but it's
  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
  */


 #include <linux/bitops.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/usb.h>
 #include <linux/moduleparam.h>
 #include <linux/mutex.h>
 #include <linux/usb/audio.h>
 #include <linux/usb/audio-v2.h>
 #include <linux/module.h>

 #include <sound/control.h>
 #include <sound/core.h>
 #include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/initval.h>

 #include "usbaudio.h"
 #include "card.h"
 #include "midi.h"
 #include "mixer.h"
 #include "proc.h"
 #include "quirks.h"
 #include "endpoint.h"
 #include "helper.h"
 #include "debug.h"
 #include "pcm.h"
 #include "format.h"
 #include "power.h"
 #include "stream.h"

 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
 MODULE_DESCRIPTION("USB Audio");
 MODULE_LICENSE("GPL");
 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");


 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
 /* Vendor/product IDs for this card */
 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
 static bool ignore_ctl_error;
 static bool autoclock = true;

 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
 module_param_array(id, charp, NULL, 0444);
 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
 module_param_array(enable, bool, NULL, 0444);
 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
 module_param_array(vid, int, NULL, 0444);
 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
 module_param_array(pid, int, NULL, 0444);
 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
 module_param_array(device_setup, int, NULL, 0444);
 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
 module_param(ignore_ctl_error, bool, 0444);
 MODULE_PARM_DESC(ignore_ctl_error,
 		 "Ignore errors from USB controller for mixer interfaces.");
 module_param(autoclock, bool, 0444);
 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");

 /*
  * we keep the snd_usb_audio_t instances by ourselves for merging
  * the all interfaces on the same card as one sound device.
  */

 static DEFINE_MUTEX(register_mutex);
 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 static struct usb_driver usb_audio_driver;

 /*
  * disconnect streams
  * called from snd_usb_audio_disconnect()
  */
 static void snd_usb_stream_disconnect(struct list_head *head)
 {
 	int idx;
 	struct snd_usb_stream *as;
 	struct snd_usb_substream *subs;

 	as = list_entry(head, struct snd_usb_stream, list);
 	for (idx = 0; idx < 2; idx++) {
 		subs = &as->substream[idx];
 		if (!subs->num_formats)
 			continue;
 		subs->interface = -1;
 		subs->data_endpoint = NULL;
 		subs->sync_endpoint = NULL;
 	}
 }

 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
 {
 	struct usb_device *dev = chip->dev;
 	struct usb_host_interface *alts;
 	struct usb_interface_descriptor *altsd;
 	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);

 	if (!iface) {
 		snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
 			   dev->devnum, ctrlif, interface);
 		return -EINVAL;
 	}

 	alts = &iface->altsetting[0];
 	altsd = get_iface_desc(alts);

 	/*
 	 * Android with both accessory and audio interfaces enabled gets the
 	 * interface numbers wrong.
 	 */
 	if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
 	     chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
 	    interface == 0 &&
 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
 	    altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
 		interface = 2;
 		iface = usb_ifnum_to_if(dev, interface);
 		if (!iface)
 			return -EINVAL;
 		alts = &iface->altsetting[0];
 		altsd = get_iface_desc(alts);
 	}

 	if (usb_interface_claimed(iface)) {
 		snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
 						dev->devnum, ctrlif, interface);
 		return -EINVAL;
 	}

 	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
 	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
 	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
 		int err = snd_usbmidi_create(chip->card, iface,
 					     &chip->midi_list, NULL);
 		if (err < 0) {
 			snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
 						dev->devnum, ctrlif, interface);
 			return -EINVAL;
 		}
 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);

 		return 0;
 	}

 	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
 	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
 	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
 		snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
 					dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
 		/* skip non-supported classes */
 		return -EINVAL;
 	}

 	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
 		snd_printk(KERN_ERR "low speed audio streaming not supported\n");
 		return -EINVAL;
 	}

 	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;
 	}

 	return 0;
 }

 /*
  * parse audio control descriptor and create pcm/midi streams
  */
 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 {
 	struct usb_device *dev = chip->dev;
 	struct usb_host_interface *host_iface;
 	struct usb_interface_descriptor *altsd;
 	void *control_header;
 	int i, protocol;

 	/* find audiocontrol interface */
 	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
 	control_header = snd_usb_find_csint_desc(host_iface->extra,
 						 host_iface->extralen,
 						 NULL, UAC_HEADER);
 	altsd = get_iface_desc(host_iface);
 	protocol = altsd->bInterfaceProtocol;

 	if (!control_header) {
 		snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
 		return -EINVAL;
 	}

 	switch (protocol) {
 	default:
 		snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
 			    protocol);
 		/* fall through */

 	case UAC_VERSION_1: {
 		struct uac1_ac_header_descriptor *h1 = control_header;

 		if (!h1->bInCollection) {
 			snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
 			return -EINVAL;
 		}

 		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
 			snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
 			return -EINVAL;
 		}

 		for (i = 0; i < h1->bInCollection; i++)
 			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);

 		break;
 	}

 	case UAC_VERSION_2: {
 		struct usb_interface_assoc_descriptor *assoc =
 			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;

 		if (!assoc) {
 			/*
 			 * Firmware writers cannot count to three.  So to find
 			 * the IAD on the NuForce UDH-100, also check the next
 			 * interface.
 			 */
 			struct usb_interface *iface =
 				usb_ifnum_to_if(dev, ctrlif + 1);
 			if (iface &&
 			    iface->intf_assoc &&
 			    iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
 			    iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
 				assoc = iface->intf_assoc;
 		}

 		if (!assoc) {
 			snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
 			return -EINVAL;
 		}

 		for (i = 0; i < assoc->bInterfaceCount; i++) {
 			int intf = assoc->bFirstInterface + i;

 			if (intf != ctrlif)
 				snd_usb_create_stream(chip, ctrlif, intf);
 		}

 		break;
 	}
 	}

 	return 0;
 }

 /*
  * free the chip instance
  *
  * here we have to do not much, since pcm and controls are already freed
  *
  */

 static int snd_usb_audio_free(struct snd_usb_audio *chip)
 {
 	mutex_destroy(&chip->mutex);
 	kfree(chip);
 	return 0;
 }

 static int snd_usb_audio_dev_free(struct snd_device *device)
 {
 	struct snd_usb_audio *chip = device->device_data;
 	return snd_usb_audio_free(chip);
 }

 static void remove_trailing_spaces(char *str)
 {
 	char *p;

 	if (!*str)
 		return;
 	for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
 		*p = 0;
 }

 /*
  * create a chip instance and set its names.
  */
 static int snd_usb_audio_create(struct usb_device *dev, int idx,
 				const struct snd_usb_audio_quirk *quirk,
 				struct snd_usb_audio **rchip)
 {
 	struct snd_card *card;
 	struct snd_usb_audio *chip;
 	int err, len;
 	char component[14];
 	static struct snd_device_ops ops = {
 		.dev_free =	snd_usb_audio_dev_free,
 	};

 	*rchip = NULL;

 	switch (snd_usb_get_speed(dev)) {
 	case USB_SPEED_LOW:
 	case USB_SPEED_FULL:
 	case USB_SPEED_HIGH:
 	case USB_SPEED_WIRELESS:
 	case USB_SPEED_SUPER:
 		break;
 	default:
 		snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
 		return -ENXIO;
 	}

 	err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
 	if (err < 0) {
 		snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
 		return err;
 	}

 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 	if (! chip) {
 		snd_card_free(card);
 		return -ENOMEM;
 	}

 	mutex_init(&chip->mutex);
 	init_rwsem(&chip->shutdown_rwsem);
 	chip->index = idx;
 	chip->dev = dev;
 	chip->card = card;
 	chip->setup = device_setup[idx];
 	chip->autoclock = autoclock;
 	chip->probing = 1;

 	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 			      le16_to_cpu(dev->descriptor.idProduct));
 	INIT_LIST_HEAD(&chip->pcm_list);
 	INIT_LIST_HEAD(&chip->ep_list);
 	INIT_LIST_HEAD(&chip->midi_list);
 	INIT_LIST_HEAD(&chip->mixer_list);

 	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
 		snd_usb_audio_free(chip);
 		snd_card_free(card);
 		return err;
 	}

 	strcpy(card->driver, "USB-Audio");
 	sprintf(component, "USB%04x:%04x",
 		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
 	snd_component_add(card, component);

 	/* retrieve the device string as shortname */
 	if (quirk && quirk->product_name && *quirk->product_name) {
 		strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
 	} else {
 		if (!dev->descriptor.iProduct ||
 		    usb_string(dev, dev->descriptor.iProduct,
 		    card->shortname, sizeof(card->shortname)) <= 0) {
 			/* no name available from anywhere, so use ID */
 			sprintf(card->shortname, "USB Device %#04x:%#04x",
 				USB_ID_VENDOR(chip->usb_id),
 				USB_ID_PRODUCT(chip->usb_id));
 		}
 	}
 	remove_trailing_spaces(card->shortname);

 	/* retrieve the vendor and device strings as longname */
 	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
 		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
 	} else {
 		if (dev->descriptor.iManufacturer)
 			len = usb_string(dev, dev->descriptor.iManufacturer,
 					 card->longname, sizeof(card->longname));
 		else
 			len = 0;
 		/* we don't really care if there isn't any vendor string */
 	}
 	if (len > 0) {
 		remove_trailing_spaces(card->longname);
 		if (*card->longname)
 			strlcat(card->longname, " ", sizeof(card->longname));
 	}

 	strlcat(card->longname, card->shortname, sizeof(card->longname));

 	len = strlcat(card->longname, " at ", sizeof(card->longname));

 	if (len < sizeof(card->longname))
 		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);

 	switch (snd_usb_get_speed(dev)) {
 	case USB_SPEED_LOW:
 		strlcat(card->longname, ", low speed", sizeof(card->longname));
 		break;
 	case USB_SPEED_FULL:
 		strlcat(card->longname, ", full speed", sizeof(card->longname));
 		break;
 	case USB_SPEED_HIGH:
 		strlcat(card->longname, ", high speed", sizeof(card->longname));
 		break;
 	case USB_SPEED_SUPER:
 		strlcat(card->longname, ", super speed", sizeof(card->longname));
 		break;
 	default:
 		break;
 	}

 	snd_usb_audio_create_proc(chip);

 	*rchip = chip;
 	return 0;
 }

 /*
  * probe the active usb device
  *
  * note that this can be called multiple times per a device, when it
  * includes multiple audio control interfaces.
  *
  * thus we check the usb device pointer and creates the card instance
  * only at the first time.  the successive calls of this function will
  * append the pcm interface to the corresponding card.
  */
 static struct snd_usb_audio *
 snd_usb_audio_probe(struct usb_device *dev,
 		    struct usb_interface *intf,
 		    const struct usb_device_id *usb_id)
 {
 	const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
 	int i, err;
 	struct snd_usb_audio *chip;
 	struct usb_host_interface *alts;
 	int ifnum;
 	u32 id;

 	alts = &intf->altsetting[0];
 	ifnum = get_iface_desc(alts)->bInterfaceNumber;
 	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 		    le16_to_cpu(dev->descriptor.idProduct));
 	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
 		goto __err_val;

 	if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
 		goto __err_val;

 	/*
 	 * found a config.  now register to ALSA
 	 */

 	/* check whether it's already registered */
 	chip = NULL;
 	mutex_lock(&register_mutex);
 	for (i = 0; i < SNDRV_CARDS; i++) {
 		if (usb_chip[i] && usb_chip[i]->dev == dev) {
 			if (usb_chip[i]->shutdown) {
 				snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
 				goto __error;
 			}
 			chip = usb_chip[i];
 			chip->probing = 1;
 			break;
 		}
 	}
 	if (! chip) {
 		/* it's a fresh one.
 		 * now look for an empty slot and create a new card instance
 		 */
 		for (i = 0; i < SNDRV_CARDS; i++)
 			if (enable[i] && ! usb_chip[i] &&
 			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
 				if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
 					goto __error;
 				}
 				snd_card_set_dev(chip->card, &intf->dev);
 				chip->pm_intf = intf;
 				break;
 			}
 		if (!chip) {
 			printk(KERN_ERR "no available usb audio device\n");
 			goto __error;
 		}
 	}

 	/*
 	 * For devices with more than one control interface, we assume the
 	 * first contains the audio controls. We might need a more specific
 	 * check here in the future.
 	 */
 	if (!chip->ctrl_intf)
 		chip->ctrl_intf = alts;

 	chip->txfr_quirk = 0;
 	err = 1; /* continue */
 	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 		/* need some special handlings */
 		if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
 			goto __error;
 	}

 	if (err > 0) {
 		/* create normal USB audio interfaces */
 		if (snd_usb_create_streams(chip, ifnum) < 0 ||
 		    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
 			goto __error;
 		}
 	}

 	/* we are allowed to call snd_card_register() many times */
 	if (snd_card_register(chip->card) < 0) {
 		goto __error;
 	}

 	usb_chip[chip->index] = chip;
 	chip->num_interfaces++;
 	chip->probing = 0;
 	mutex_unlock(&register_mutex);
 	return chip;

  __error:
 	if (chip) {
 		if (!chip->num_interfaces)
 			snd_card_free(chip->card);
 		chip->probing = 0;
 	}
 	mutex_unlock(&register_mutex);
  __err_val:
 	return NULL;
 }

 /*
  * we need to take care of counter, since disconnection can be called also
  * many times as well as usb_audio_probe().
  */
 static void snd_usb_audio_disconnect(struct usb_device *dev,
 				     struct snd_usb_audio *chip)
 {
 	struct snd_card *card;
 	struct list_head *p, *n;

 	if (chip == (void *)-1L)
 		return;

 	card = chip->card;
 	down_write(&chip->shutdown_rwsem);
 	chip->shutdown = 1;
 	up_write(&chip->shutdown_rwsem);

 	mutex_lock(&register_mutex);
 	chip->num_interfaces--;
 	if (chip->num_interfaces <= 0) {
 		snd_card_disconnect(card);
 		/* release the pcm resources */
 		list_for_each(p, &chip->pcm_list) {
 			snd_usb_stream_disconnect(p);
 		}
 		/* release the endpoint resources */
 		list_for_each_safe(p, n, &chip->ep_list) {
 			snd_usb_endpoint_free(p);
 		}
 		/* release the midi resources */
 		list_for_each(p, &chip->midi_list) {
 			snd_usbmidi_disconnect(p);
 		}
 		/* release mixer resources */
 		list_for_each(p, &chip->mixer_list) {
 			snd_usb_mixer_disconnect(p);
 		}
 		usb_chip[chip->index] = NULL;
 		mutex_unlock(&register_mutex);
 		snd_card_free_when_closed(card);
 	} else {
 		mutex_unlock(&register_mutex);
 	}
 }

 /*
  * new 2.5 USB kernel API
  */
 static int usb_audio_probe(struct usb_interface *intf,
 			   const struct usb_device_id *id)
 {
 	struct snd_usb_audio *chip;
 	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
 	if (chip) {
 		usb_set_intfdata(intf, chip);
 		return 0;
 	} else
 		return -EIO;
 }

 static void usb_audio_disconnect(struct usb_interface *intf)
 {
 	snd_usb_audio_disconnect(interface_to_usbdev(intf),
 				 usb_get_intfdata(intf));
 }

 #ifdef CONFIG_PM

 int snd_usb_autoresume(struct snd_usb_audio *chip)
 {
 	int err = -ENODEV;

 	down_read(&chip->shutdown_rwsem);
 	if (chip->probing)
 		err = 0;
 	else if (!chip->shutdown)
 		err = usb_autopm_get_interface(chip->pm_intf);
 	up_read(&chip->shutdown_rwsem);

 	return err;
 }

 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 {
 	down_read(&chip->shutdown_rwsem);
 	if (!chip->shutdown && !chip->probing)
 		usb_autopm_put_interface(chip->pm_intf);
 	up_read(&chip->shutdown_rwsem);
 }

 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
 	struct snd_usb_stream *as;
 	struct usb_mixer_interface *mixer;

 	if (chip == (void *)-1L)
 		return 0;

 	if (!PMSG_IS_AUTO(message)) {
 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 		if (!chip->num_suspended_intf++) {
 			list_for_each_entry(as, &chip->pcm_list, list) {
 				snd_pcm_suspend_all(as->pcm);
 				as->substream[0].need_setup_ep =
 					as->substream[1].need_setup_ep = true;
 			}
 		}
 	} else {
 		/*
 		 * otherwise we keep the rest of the system in the dark
 		 * to keep this transparent
 		 */
 		if (!chip->num_suspended_intf++)
 			chip->autosuspended = 1;
 	}

 	list_for_each_entry(mixer, &chip->mixer_list, list)
 		snd_usb_mixer_inactivate(mixer);

 	return 0;
 }

 static int usb_audio_resume(struct usb_interface *intf)
 {
 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
 	struct usb_mixer_interface *mixer;
 	int err = 0;

 	if (chip == (void *)-1L)
 		return 0;
 	if (--chip->num_suspended_intf)
 		return 0;
 	/*
 	 * ALSA leaves material resumption to user space
 	 * we just notify and restart the mixers
 	 */
 	list_for_each_entry(mixer, &chip->mixer_list, list) {
 		err = snd_usb_mixer_activate(mixer);
 		if (err < 0)
 			goto err_out;
 	}

 	if (!chip->autosuspended)
 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 	chip->autosuspended = 0;

 err_out:
 	return err;
 }
 #else
 #define usb_audio_suspend	NULL
 #define usb_audio_resume	NULL
 #endif		/* CONFIG_PM */

 static struct usb_device_id usb_audio_ids [] = {
 #include "quirks-table.h"
     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
       .bInterfaceClass = USB_CLASS_AUDIO,
       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
     { }						/* Terminating entry */
 };
 MODULE_DEVICE_TABLE(usb, usb_audio_ids);

 /*
  * entry point for linux usb interface
  */

 static struct usb_driver usb_audio_driver = {
 	.name =		"snd-usb-audio",
 	.probe =	usb_audio_probe,
 	.disconnect =	usb_audio_disconnect,
 	.suspend =	usb_audio_suspend,
 	.resume =	usb_audio_resume,
 	.id_table =	usb_audio_ids,
 	.supports_autosuspend = 1,
 };

 module_usb_driver(usb_audio_driver);
	/*
	* (Tentative) USB Audio Driver for ALSA
	*
	* Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
	*
	* Many codes borrowed from audio.c by
	* Alan Cox (alan@lxorguk.ukuu.org.uk)
	* Thomas Sailer (sailer@ife.ee.ethz.ch)
	*
	*
	* 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
	*
	*
	* NOTES:
	*
	* - the linked URBs would be preferred but not used so far because of
	* the instability of unlinking.
	* - type II is not supported properly. there is no device which supports
	* this type correctly. SB extigy looks as if it supports, but it's
	* indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
	*/


	#include <linux/bitops.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/ctype.h>
	#include <linux/usb.h>
	#include <linux/moduleparam.h>
	#include <linux/mutex.h>
	#include <linux/usb/audio.h>
	#include <linux/usb/audio-v2.h>
	#include <linux/module.h>

	#include <sound/control.h>
	#include <sound/core.h>
	#include <sound/info.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/initval.h>

	#include "usbaudio.h"
	#include "card.h"
	#include "midi.h"
	#include "mixer.h"
	#include "proc.h"
	#include "quirks.h"
	#include "endpoint.h"
	#include "helper.h"
	#include "debug.h"
	#include "pcm.h"
	#include "format.h"
	#include "power.h"
	#include "stream.h"

	MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
	MODULE_DESCRIPTION("USB Audio");
	MODULE_LICENSE("GPL");
	MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");


	static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
	static char id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; / ID for this card */
	static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
	/* Vendor/product IDs for this card */
	static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
	static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
	static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
	static bool ignore_ctl_error;
	static bool autoclock = true;

	module_param_array(index, int, NULL, 0444);
	MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
	module_param_array(id, charp, NULL, 0444);
	MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
	module_param_array(enable, bool, NULL, 0444);
	MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
	module_param_array(vid, int, NULL, 0444);
	MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
	module_param_array(pid, int, NULL, 0444);
	MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
	module_param_array(device_setup, int, NULL, 0444);
	MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
	module_param(ignore_ctl_error, bool, 0444);
	MODULE_PARM_DESC(ignore_ctl_error,
	"Ignore errors from USB controller for mixer interfaces.");
	module_param(autoclock, bool, 0444);
	MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");

	/*
	* we keep the snd_usb_audio_t instances by ourselves for merging
	* the all interfaces on the same card as one sound device.
	*/

	static DEFINE_MUTEX(register_mutex);
	static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
	static struct usb_driver usb_audio_driver;

	/*
	* disconnect streams
	* called from snd_usb_audio_disconnect()
	*/
	static void snd_usb_stream_disconnect(struct list_head *head)
	{
	int idx;
	struct snd_usb_stream *as;
	struct snd_usb_substream *subs;

	as = list_entry(head, struct snd_usb_stream, list);
	for (idx = 0; idx < 2; idx++) {
	subs = &as->substream[idx];
	if (!subs->num_formats)
	continue;
	subs->interface = -1;
	subs->data_endpoint = NULL;
	subs->sync_endpoint = NULL;
	}
	}

	static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
	{
	struct usb_device *dev = chip->dev;
	struct usb_host_interface *alts;
	struct usb_interface_descriptor *altsd;
	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);

	if (!iface) {
	snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
	dev->devnum, ctrlif, interface);
	return -EINVAL;
	}

	alts = &iface->altsetting[0];
	altsd = get_iface_desc(alts);

	/*
	* Android with both accessory and audio interfaces enabled gets the
	* interface numbers wrong.
	*/
	if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) \|\|
	chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
	interface == 0 &&
	altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
	altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
	interface = 2;
	iface = usb_ifnum_to_if(dev, interface);
	if (!iface)
	return -EINVAL;
	alts = &iface->altsetting[0];
	altsd = get_iface_desc(alts);
	}

	if (usb_interface_claimed(iface)) {
	snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
	dev->devnum, ctrlif, interface);
	return -EINVAL;
	}

	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO \|\|
	altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
	altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
	int err = snd_usbmidi_create(chip->card, iface,
	&chip->midi_list, NULL);
	if (err < 0) {
	snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
	dev->devnum, ctrlif, interface);
	return -EINVAL;
	}
	usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);

	return 0;
	}

	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
	altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) \|\|
	altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
	snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
	dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
	/* skip non-supported classes */
	return -EINVAL;
	}

	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
	snd_printk(KERN_ERR "low speed audio streaming not supported\n");
	return -EINVAL;
	}

	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;
	}

	return 0;
	}

	/*
	* parse audio control descriptor and create pcm/midi streams
	*/
	static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
	{
	struct usb_device *dev = chip->dev;
	struct usb_host_interface *host_iface;
	struct usb_interface_descriptor *altsd;
	void *control_header;
	int i, protocol;

	/* find audiocontrol interface */
	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
	control_header = snd_usb_find_csint_desc(host_iface->extra,
	host_iface->extralen,
	NULL, UAC_HEADER);
	altsd = get_iface_desc(host_iface);
	protocol = altsd->bInterfaceProtocol;

	if (!control_header) {
	snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
	return -EINVAL;
	}

	switch (protocol) {
	default:
	snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
	protocol);
	/* fall through */

	case UAC_VERSION_1: {
	struct uac1_ac_header_descriptor *h1 = control_header;

	if (!h1->bInCollection) {
	snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
	return -EINVAL;
	}

	if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
	snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
	return -EINVAL;
	}

	for (i = 0; i < h1->bInCollection; i++)
	snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);

	break;
	}

	case UAC_VERSION_2: {
	struct usb_interface_assoc_descriptor *assoc =
	usb_ifnum_to_if(dev, ctrlif)->intf_assoc;

	if (!assoc) {
	/*
	* Firmware writers cannot count to three. So to find
	* the IAD on the NuForce UDH-100, also check the next
	* interface.
	*/
	struct usb_interface *iface =
	usb_ifnum_to_if(dev, ctrlif + 1);
	if (iface &&
	iface->intf_assoc &&
	iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
	iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
	assoc = iface->intf_assoc;
	}

	if (!assoc) {
	snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
	return -EINVAL;
	}

	for (i = 0; i < assoc->bInterfaceCount; i++) {
	int intf = assoc->bFirstInterface + i;

	if (intf != ctrlif)
	snd_usb_create_stream(chip, ctrlif, intf);
	}

	break;
	}
	}

	return 0;
	}

	/*
	* free the chip instance
	*
	* here we have to do not much, since pcm and controls are already freed
	*
	*/

	static int snd_usb_audio_free(struct snd_usb_audio *chip)
	{
	mutex_destroy(&chip->mutex);
	kfree(chip);
	return 0;
	}

	static int snd_usb_audio_dev_free(struct snd_device *device)
	{
	struct snd_usb_audio *chip = device->device_data;
	return snd_usb_audio_free(chip);
	}

	static void remove_trailing_spaces(char *str)
	{
	char *p;

	if (!*str)
	return;
	for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
	*p = 0;
	}

	/*
	* create a chip instance and set its names.
	*/
	static int snd_usb_audio_create(struct usb_device *dev, int idx,
	const struct snd_usb_audio_quirk *quirk,
	struct snd_usb_audio **rchip)
	{
	struct snd_card *card;
	struct snd_usb_audio *chip;
	int err, len;
	char component[14];
	static struct snd_device_ops ops = {
	.dev_free = snd_usb_audio_dev_free,
	};

	*rchip = NULL;

	switch (snd_usb_get_speed(dev)) {
	case USB_SPEED_LOW:
	case USB_SPEED_FULL:
	case USB_SPEED_HIGH:
	case USB_SPEED_WIRELESS:
	case USB_SPEED_SUPER:
	break;
	default:
	snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
	return -ENXIO;
	}

	err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
	if (err < 0) {
	snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
	return err;
	}

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (! chip) {
	snd_card_free(card);
	return -ENOMEM;
	}

	mutex_init(&chip->mutex);
	init_rwsem(&chip->shutdown_rwsem);
	chip->index = idx;
	chip->dev = dev;
	chip->card = card;
	chip->setup = device_setup[idx];
	chip->autoclock = autoclock;
	chip->probing = 1;

	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
	le16_to_cpu(dev->descriptor.idProduct));
	INIT_LIST_HEAD(&chip->pcm_list);
	INIT_LIST_HEAD(&chip->ep_list);
	INIT_LIST_HEAD(&chip->midi_list);
	INIT_LIST_HEAD(&chip->mixer_list);

	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
	snd_usb_audio_free(chip);
	snd_card_free(card);
	return err;
	}

	strcpy(card->driver, "USB-Audio");
	sprintf(component, "USB%04x:%04x",
	USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
	snd_component_add(card, component);

	/* retrieve the device string as shortname */
	if (quirk && quirk->product_name && *quirk->product_name) {
	strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
	} else {
	if (!dev->descriptor.iProduct \|\|
	usb_string(dev, dev->descriptor.iProduct,
	card->shortname, sizeof(card->shortname)) <= 0) {
	/* no name available from anywhere, so use ID */
	sprintf(card->shortname, "USB Device %#04x:%#04x",
	USB_ID_VENDOR(chip->usb_id),
	USB_ID_PRODUCT(chip->usb_id));
	}
	}
	remove_trailing_spaces(card->shortname);

	/* retrieve the vendor and device strings as longname */
	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
	len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
	} else {
	if (dev->descriptor.iManufacturer)
	len = usb_string(dev, dev->descriptor.iManufacturer,
	card->longname, sizeof(card->longname));
	else
	len = 0;
	/* we don't really care if there isn't any vendor string */
	}
	if (len > 0) {
	remove_trailing_spaces(card->longname);
	if (*card->longname)
	strlcat(card->longname, " ", sizeof(card->longname));
	}

	strlcat(card->longname, card->shortname, sizeof(card->longname));

	len = strlcat(card->longname, " at ", sizeof(card->longname));

	if (len < sizeof(card->longname))
	usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);

	switch (snd_usb_get_speed(dev)) {
	case USB_SPEED_LOW:
	strlcat(card->longname, ", low speed", sizeof(card->longname));
	break;
	case USB_SPEED_FULL:
	strlcat(card->longname, ", full speed", sizeof(card->longname));
	break;
	case USB_SPEED_HIGH:
	strlcat(card->longname, ", high speed", sizeof(card->longname));
	break;
	case USB_SPEED_SUPER:
	strlcat(card->longname, ", super speed", sizeof(card->longname));
	break;
	default:
	break;
	}

	snd_usb_audio_create_proc(chip);

	*rchip = chip;
	return 0;
	}

	/*
	* probe the active usb device
	*
	* note that this can be called multiple times per a device, when it
	* includes multiple audio control interfaces.
	*
	* thus we check the usb device pointer and creates the card instance
	* only at the first time. the successive calls of this function will
	* append the pcm interface to the corresponding card.
	*/
	static struct snd_usb_audio *
	snd_usb_audio_probe(struct usb_device *dev,
	struct usb_interface *intf,
	const struct usb_device_id *usb_id)
	{
	const struct snd_usb_audio_quirk quirk = (const struct snd_usb_audio_quirk )usb_id->driver_info;
	int i, err;
	struct snd_usb_audio *chip;
	struct usb_host_interface *alts;
	int ifnum;
	u32 id;

	alts = &intf->altsetting[0];
	ifnum = get_iface_desc(alts)->bInterfaceNumber;
	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
	le16_to_cpu(dev->descriptor.idProduct));
	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
	goto __err_val;

	if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
	goto __err_val;

	/*
	* found a config. now register to ALSA
	*/

	/* check whether it's already registered */
	chip = NULL;
	mutex_lock(&register_mutex);
	for (i = 0; i < SNDRV_CARDS; i++) {
	if (usb_chip[i] && usb_chip[i]->dev == dev) {
	if (usb_chip[i]->shutdown) {
	snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
	goto __error;
	}
	chip = usb_chip[i];
	chip->probing = 1;
	break;
	}
	}
	if (! chip) {
	/* it's a fresh one.
	* now look for an empty slot and create a new card instance
	*/
	for (i = 0; i < SNDRV_CARDS; i++)
	if (enable[i] && ! usb_chip[i] &&
	(vid[i] == -1 \|\| vid[i] == USB_ID_VENDOR(id)) &&
	(pid[i] == -1 \|\| pid[i] == USB_ID_PRODUCT(id))) {
	if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
	goto __error;
	}
	snd_card_set_dev(chip->card, &intf->dev);
	chip->pm_intf = intf;
	break;
	}
	if (!chip) {
	printk(KERN_ERR "no available usb audio device\n");
	goto __error;
	}
	}

	/*
	* For devices with more than one control interface, we assume the
	* first contains the audio controls. We might need a more specific
	* check here in the future.
	*/
	if (!chip->ctrl_intf)
	chip->ctrl_intf = alts;

	chip->txfr_quirk = 0;
	err = 1; /* continue */
	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
	/* need some special handlings */
	if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
	goto __error;
	}

	if (err > 0) {
	/* create normal USB audio interfaces */
	if (snd_usb_create_streams(chip, ifnum) < 0 \|\|
	snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
	goto __error;
	}
	}

	/* we are allowed to call snd_card_register() many times */
	if (snd_card_register(chip->card) < 0) {
	goto __error;
	}

	usb_chip[chip->index] = chip;
	chip->num_interfaces++;
	chip->probing = 0;
	mutex_unlock(&register_mutex);
	return chip;

	__error:
	if (chip) {
	if (!chip->num_interfaces)
	snd_card_free(chip->card);
	chip->probing = 0;
	}
	mutex_unlock(&register_mutex);
	__err_val:
	return NULL;
	}

	/*
	* we need to take care of counter, since disconnection can be called also
	* many times as well as usb_audio_probe().
	*/
	static void snd_usb_audio_disconnect(struct usb_device *dev,
	struct snd_usb_audio *chip)
	{
	struct snd_card *card;
	struct list_head p, n;

	if (chip == (void *)-1L)
	return;

	card = chip->card;
	down_write(&chip->shutdown_rwsem);
	chip->shutdown = 1;
	up_write(&chip->shutdown_rwsem);

	mutex_lock(&register_mutex);
	chip->num_interfaces--;
	if (chip->num_interfaces <= 0) {
	snd_card_disconnect(card);
	/* release the pcm resources */
	list_for_each(p, &chip->pcm_list) {
	snd_usb_stream_disconnect(p);
	}
	/* release the endpoint resources */
	list_for_each_safe(p, n, &chip->ep_list) {
	snd_usb_endpoint_free(p);
	}
	/* release the midi resources */
	list_for_each(p, &chip->midi_list) {
	snd_usbmidi_disconnect(p);
	}
	/* release mixer resources */
	list_for_each(p, &chip->mixer_list) {
	snd_usb_mixer_disconnect(p);
	}
	usb_chip[chip->index] = NULL;
	mutex_unlock(&register_mutex);
	snd_card_free_when_closed(card);
	} else {
	mutex_unlock(&register_mutex);
	}
	}

	/*
	* new 2.5 USB kernel API
	*/
	static int usb_audio_probe(struct usb_interface *intf,
	const struct usb_device_id *id)
	{
	struct snd_usb_audio *chip;
	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
	if (chip) {
	usb_set_intfdata(intf, chip);
	return 0;
	} else
	return -EIO;
	}

	static void usb_audio_disconnect(struct usb_interface *intf)
	{
	snd_usb_audio_disconnect(interface_to_usbdev(intf),
	usb_get_intfdata(intf));
	}

	#ifdef CONFIG_PM

	int snd_usb_autoresume(struct snd_usb_audio *chip)
	{
	int err = -ENODEV;

	down_read(&chip->shutdown_rwsem);
	if (chip->probing)
	err = 0;
	else if (!chip->shutdown)
	err = usb_autopm_get_interface(chip->pm_intf);
	up_read(&chip->shutdown_rwsem);

	return err;
	}

	void snd_usb_autosuspend(struct snd_usb_audio *chip)
	{
	down_read(&chip->shutdown_rwsem);
	if (!chip->shutdown && !chip->probing)
	usb_autopm_put_interface(chip->pm_intf);
	up_read(&chip->shutdown_rwsem);
	}

	static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
	{
	struct snd_usb_audio *chip = usb_get_intfdata(intf);
	struct snd_usb_stream *as;
	struct usb_mixer_interface *mixer;

	if (chip == (void *)-1L)
	return 0;

	if (!PMSG_IS_AUTO(message)) {
	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
	if (!chip->num_suspended_intf++) {
	list_for_each_entry(as, &chip->pcm_list, list) {
	snd_pcm_suspend_all(as->pcm);
	as->substream[0].need_setup_ep =
	as->substream[1].need_setup_ep = true;
	}
	}
	} else {
	/*
	* otherwise we keep the rest of the system in the dark
	* to keep this transparent
	*/
	if (!chip->num_suspended_intf++)
	chip->autosuspended = 1;
	}

	list_for_each_entry(mixer, &chip->mixer_list, list)
	snd_usb_mixer_inactivate(mixer);

	return 0;
	}

	static int usb_audio_resume(struct usb_interface *intf)
	{
	struct snd_usb_audio *chip = usb_get_intfdata(intf);
	struct usb_mixer_interface *mixer;
	int err = 0;

	if (chip == (void *)-1L)
	return 0;
	if (--chip->num_suspended_intf)
	return 0;
	/*
	* ALSA leaves material resumption to user space
	* we just notify and restart the mixers
	*/
	list_for_each_entry(mixer, &chip->mixer_list, list) {
	err = snd_usb_mixer_activate(mixer);
	if (err < 0)
	goto err_out;
	}

	if (!chip->autosuspended)
	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
	chip->autosuspended = 0;

	err_out:
	return err;
	}
	#else
	#define usb_audio_suspend NULL
	#define usb_audio_resume NULL
	#endif /* CONFIG_PM */

	static struct usb_device_id usb_audio_ids [] = {
	#include "quirks-table.h"
	{ .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS \| USB_DEVICE_ID_MATCH_INT_SUBCLASS),
	.bInterfaceClass = USB_CLASS_AUDIO,
	.bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
	{ } /* Terminating entry */
	};
	MODULE_DEVICE_TABLE(usb, usb_audio_ids);

	/*
	* entry point for linux usb interface
	*/

	static struct usb_driver usb_audio_driver = {
	.name = "snd-usb-audio",
	.probe = usb_audio_probe,
	.disconnect = usb_audio_disconnect,
	.suspend = usb_audio_suspend,
	.resume = usb_audio_resume,
	.id_table = usb_audio_ids,
	.supports_autosuspend = 1,
	};

	module_usb_driver(usb_audio_driver);