ALSA: usb-audio: refactor code

# Makefile for ALSA

#

snd-usb-audio-objs := usbaudio.o usbmixer.o

snd-usbmidi-lib-objs := usbmidi.o

snd-usb-audio-objs := 	card.o \

			usbmixer.o \

			proc.o \

			quirks.o \

			format.o \

			endpoint.o \

			urb.o \

			pcm.o \

			helper.o

snd-usbmidi-lib-objs := midi.o

# Toplevel Module Dependency

obj-$(CONFIG_SND_USB_AUDIO) += snd-usb-audio.o snd-usbmidi-lib.o

/*

 *   (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:

 *

 *   - async unlink should be used for avoiding the sleep inside lock.

 *     2.4.22 usb-uhci seems buggy for async unlinking and results in

 *     oops.  in such a cse, pass async_unlink=0 option.

 *   - 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/usb.h>

#include <linux/moduleparam.h>

#include <linux/mutex.h>

#include <linux/usb/audio.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 "usbmixer.h"

#include "proc.h"

#include "quirks.h"

#include "endpoint.h"

#include "helper.h"

#include "debug.h"

#include "pcm.h"

#include "urb.h"

#include "format.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 int 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 nrpacks = 8;		/* max. number of packets per urb */

static int async_unlink = 1;

static int device_setup[SNDRV_CARDS]; /* device parameter for this card */

static int ignore_ctl_error;

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(nrpacks, int, 0644);

MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");

module_param(async_unlink, bool, 0444);

MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");

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.");

/*

 * 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)

			return;

		snd_usb_release_substream_urbs(subs, 1);

		subs->interface = -1;

	}

}

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;

	}

	if (usb_interface_claimed(iface)) {

		snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",

						dev->devnum, ctrlif, interface);

		return -EINVAL;

	}

	alts = &iface->altsetting[0];

	altsd = get_iface_desc(alts);

	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_endpoints(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) {

	case UAC_VERSION_1: {

		struct uac_ac_header_descriptor_v1 *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 uac_clock_source_descriptor *cs;

		struct usb_interface_assoc_descriptor *assoc =

			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;

		if (!assoc) {

			snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");

			return -EINVAL;

		}

		/* FIXME: for now, we expect there is at least one clock source

		 * descriptor and we always take the first one.

		 * We should properly support devices with multiple clock sources,

		 * clock selectors and sample rate conversion units. */

		cs = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen,

						NULL, UAC_CLOCK_SOURCE);

		if (!cs) {

			snd_printk(KERN_ERR "CLOCK_SOURCE descriptor not found\n");

			return -EINVAL;

		}

		chip->clock_id = cs->bClockID;

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

			int intf = assoc->bFirstInterface + i;

			if (intf != ctrlif)

				snd_usb_create_stream(chip, ctrlif, intf);

		}

		break;

	}

	default:

		snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);

		return -EINVAL;

	}

	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)

{

	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);

}

/*

 * 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;

	if (snd_usb_get_speed(dev) != USB_SPEED_LOW &&

	    snd_usb_get_speed(dev) != USB_SPEED_FULL &&

	    snd_usb_get_speed(dev) != USB_SPEED_HIGH) {

		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;

	}

	chip->index = idx;

	chip->dev = dev;

	chip->card = card;

	chip->setup = device_setup[idx];

	chip->nrpacks = nrpacks;

	chip->async_unlink = async_unlink;

	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->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) {

		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));

		}

	}

	/* retrieve the vendor and device strings as longname */

	if (quirk && 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)

		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);

	strlcat(card->longname,

		snd_usb_get_speed(dev) == USB_SPEED_LOW ? ", low speed" :

		snd_usb_get_speed(dev) == USB_SPEED_FULL ? ", full speed" :

		", high speed",

		sizeof(card->longname));

	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 void *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];

			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);

				break;

			}

		if (!chip) {

			printk(KERN_ERR "no available usb audio device\n");

			goto __error;

		}

	}

	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++;

	mutex_unlock(&register_mutex);

	return chip;

 __error:

	if (chip && !chip->num_interfaces)

		snd_card_free(chip->card);

	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, void *ptr)

{

	struct snd_usb_audio *chip;

	struct snd_card *card;

	struct list_head *p;

	if (ptr == (void *)-1L)

		return;

	chip = ptr;

	card = chip->card;

	mutex_lock(&register_mutex);

	chip->shutdown = 1;

	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 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)

{

	void *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

static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)

{

	struct snd_usb_audio *chip = usb_get_intfdata(intf);

	struct list_head *p;

	struct snd_usb_stream *as;

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

		return 0;

	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);

	if (!chip->num_suspended_intf++) {

		list_for_each(p, &chip->pcm_list) {

			as = list_entry(p, struct snd_usb_stream, list);

			snd_pcm_suspend_all(as->pcm);

		}

	}

	return 0;

}

static int usb_audio_resume(struct usb_interface *intf)

{

	struct snd_usb_audio *chip = usb_get_intfdata(intf);

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

		return 0;

	if (--chip->num_suspended_intf)

		return 0;

	/*

	 * ALSA leaves material resumption to user space

	 * we just notify

	 */

	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);

	return 0;

}

#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,

};

static int __init snd_usb_audio_init(void)

{

	if (nrpacks < 1 || nrpacks > MAX_PACKS) {

		printk(KERN_WARNING "invalid nrpacks value.\n");

		return -EINVAL;

	}

	return usb_register(&usb_audio_driver);

}

static void __exit snd_usb_audio_cleanup(void)

{

	usb_deregister(&usb_audio_driver);

}

module_init(snd_usb_audio_init);

module_exit(snd_usb_audio_cleanup);

#ifndef __USBAUDIO_CARD_H

#define __USBAUDIO_CARD_H

#define MAX_PACKS	20

#define MAX_PACKS_HS	(MAX_PACKS * 8)	/* in high speed mode */

#define MAX_URBS	8

#define SYNC_URBS	4	/* always four urbs for sync */

#define MAX_QUEUE	24	/* try not to exceed this queue length, in ms */

struct audioformat {

	struct list_head list;

	snd_pcm_format_t format;	/* format type */

	unsigned int channels;		/* # channels */

	unsigned int fmt_type;		/* USB audio format type (1-3) */

	unsigned int frame_size;	/* samples per frame for non-audio */

	int iface;			/* interface number */

	unsigned char altsetting;	/* corresponding alternate setting */

	unsigned char altset_idx;	/* array index of altenate setting */

	unsigned char attributes;	/* corresponding attributes of cs endpoint */

	unsigned char endpoint;		/* endpoint */

	unsigned char ep_attr;		/* endpoint attributes */

	unsigned char datainterval;	/* log_2 of data packet interval */

	unsigned int maxpacksize;	/* max. packet size */

	unsigned int rates;		/* rate bitmasks */

	unsigned int rate_min, rate_max;	/* min/max rates */

	unsigned int nr_rates;		/* number of rate table entries */

	unsigned int *rate_table;	/* rate table */

};