xref: /src/sys/dev/usb/uaudio.c

/*	$NetBSD: uaudio.c,v 1.78 2004/10/02 19:14:54 kent Exp $	*/

/*
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart (at) augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * USB audio specs: http://www.usb.org/developers/devclass_docs/audio10.pdf
 *                  http://www.usb.org/developers/devclass_docs/frmts10.pdf
 *                  http://www.usb.org/developers/devclass_docs/termt10.pdf
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uaudio.c,v 1.78 2004/10/02 19:14:54 kent Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/reboot.h>		/* for bootverbose */
#include <sys/select.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/device.h>
#include <sys/poll.h>

#include <sys/audioio.h>
#include <dev/audio_if.h>
#include <dev/audiovar.h>
#include <dev/mulaw.h>
#include <dev/auconv.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usb_quirks.h>

#include <dev/usb/uaudioreg.h>

#ifdef UAUDIO_DEBUG
#define DPRINTF(x)	if (uaudiodebug) logprintf x
#define DPRINTFN(n,x)	if (uaudiodebug>(n)) logprintf x
int	uaudiodebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

#define UAUDIO_NCHANBUFS 6	/* number of outstanding request */
#define UAUDIO_NFRAMES   10	/* ms of sound in each request */


#define MIX_MAX_CHAN 8
struct mixerctl {
	u_int16_t	wValue[MIX_MAX_CHAN]; /* using nchan */
	u_int16_t	wIndex;
	u_int8_t	nchan;
	u_int8_t	type;
#define MIX_ON_OFF	1
#define MIX_SIGNED_16	2
#define MIX_UNSIGNED_16	3
#define MIX_SIGNED_8	4
#define MIX_SIZE(n) ((n) == MIX_SIGNED_16 || (n) == MIX_UNSIGNED_16 ? 2 : 1)
#define MIX_UNSIGNED(n) ((n) == MIX_UNSIGNED_16)
	int		minval, maxval;
	u_int		delta;
	u_int		mul;
	u_int8_t	class;
	char		ctlname[MAX_AUDIO_DEV_LEN];
	char		*ctlunit;
};
#define MAKE(h,l) (((h) << 8) | (l))

struct as_info {
	u_int8_t	alt;
	u_int8_t	encoding;
	u_int8_t	attributes; /* Copy of bmAttributes of
				     * usb_audio_streaming_endpoint_descriptor
				     */
	usbd_interface_handle	ifaceh;
	const usb_interface_descriptor_t *idesc;
	const usb_endpoint_descriptor_audio_t *edesc;
	const struct usb_audio_streaming_type1_descriptor *asf1desc;
	int		sc_busy;	/* currently used */
};

struct chan {
	void	(*intr)(void *);	/* DMA completion intr handler */
	void	*arg;		/* arg for intr() */
	usbd_pipe_handle pipe;

	u_int	sample_size;
	u_int	sample_rate;
	u_int	bytes_per_frame;
	u_int	fraction;	/* fraction/1000 is the extra samples/frame */
	u_int	residue;	/* accumulates the fractional samples */

	u_char	*start;		/* upper layer buffer start */
	u_char	*end;		/* upper layer buffer end */
	u_char	*cur;		/* current position in upper layer buffer */
	int	blksize;	/* chunk size to report up */
	int	transferred;	/* transferred bytes not reported up */

	int	altidx;		/* currently used altidx */

	int	curchanbuf;
	struct chanbuf {
		struct chan	*chan;
		usbd_xfer_handle xfer;
		u_char		*buffer;
		u_int16_t	sizes[UAUDIO_NFRAMES];
		u_int16_t	offsets[UAUDIO_NFRAMES];
		u_int16_t	size;
	} chanbufs[UAUDIO_NCHANBUFS];

	struct uaudio_softc *sc; /* our softc */
};

struct uaudio_softc {
	USBBASEDEVICE sc_dev;		/* base device */
	usbd_device_handle sc_udev;	/* USB device */

	int	sc_ac_iface;	/* Audio Control interface */
	usbd_interface_handle	sc_ac_ifaceh;

	struct chan sc_playchan;	/* play channel */
	struct chan sc_recchan;		/* record channel */

	int	sc_nullalt;

	int	sc_audio_rev;

	struct as_info *sc_alts;
	int	sc_nalts;

	int	sc_altflags;
#define HAS_8		0x01
#define HAS_16		0x02
#define HAS_8U		0x04
#define HAS_ALAW	0x08
#define HAS_MULAW	0x10
#define UA_NOFRAC	0x20		/* don't do sample rate adjustment */
#define HAS_24		0x40

	int	sc_mode;		/* play/record capability */

	struct mixerctl *sc_ctls;
	int	sc_nctls;

	device_ptr_t sc_audiodev;
	char	sc_dying;
};

#define UAC_OUTPUT 0
#define UAC_INPUT  1
#define UAC_EQUAL  2
#define UAC_NCLASSES 3

Static usbd_status uaudio_identify_ac(struct uaudio_softc *,
				      const usb_config_descriptor_t *);
Static usbd_status uaudio_identify_as(struct uaudio_softc *,
				      const usb_config_descriptor_t *);
Static usbd_status uaudio_process_as(struct uaudio_softc *,
				     const char *, int *, int,
				     const usb_interface_descriptor_t *);

Static void	uaudio_add_alt(struct uaudio_softc *, const struct as_info *);
Static void	uaudio_mixer_alias_ctl(struct uaudio_softc *,
				       struct mixerctl *, const char *);

Static const usb_interface_descriptor_t *uaudio_find_iface
	(const char *, int, int *, int);

Static void	uaudio_mixer_add_ctl(struct uaudio_softc *, struct mixerctl *);
Static char	*uaudio_id_name(struct uaudio_softc *,
		    const usb_descriptor_t **, int);
Static struct usb_audio_cluster uaudio_get_cluster(int,
		    const usb_descriptor_t **);
Static void	uaudio_add_input(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_output(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_mixer(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_selector(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_feature(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_processing_updown(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_processing(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static void	uaudio_add_extension(struct uaudio_softc *,
		    const usb_descriptor_t *, const usb_descriptor_t **);
Static usbd_status uaudio_identify(struct uaudio_softc *,
		    const usb_config_descriptor_t *);

Static int	uaudio_signext(int, int);
Static int	uaudio_value2bsd(struct mixerctl *, int);
Static int	uaudio_bsd2value(struct mixerctl *, int);
Static int	uaudio_get(struct uaudio_softc *, int, int, int, int, int);
Static int	uaudio_ctl_get(struct uaudio_softc *, int,
			       struct mixerctl *, int);
Static void	uaudio_set(struct uaudio_softc *, int,
			   int, int, int, int, int);
Static void	uaudio_ctl_set(struct uaudio_softc *, int,
			       struct mixerctl *, int, int);

Static usbd_status uaudio_set_speed(struct uaudio_softc *, int, u_int);

Static usbd_status uaudio_chan_open(struct uaudio_softc *, struct chan *);
Static void	uaudio_chan_close(struct uaudio_softc *, struct chan *);
Static usbd_status uaudio_chan_alloc_buffers(struct uaudio_softc *,
					     struct chan *);
Static void	uaudio_chan_free_buffers(struct uaudio_softc *, struct chan *);
Static void	uaudio_chan_init(struct chan *, int,
				 const struct audio_params *, int);
Static void	uaudio_chan_set_param(struct chan *, u_char *, u_char *, int);
Static void	uaudio_chan_ptransfer(struct chan *);
Static void	uaudio_chan_pintr(usbd_xfer_handle,
				  usbd_private_handle, usbd_status);

Static void	uaudio_chan_rtransfer(struct chan *);
Static void	uaudio_chan_rintr(usbd_xfer_handle,
				  usbd_private_handle, usbd_status);

Static int	uaudio_open(void *, int);
Static void	uaudio_close(void *);
Static int	uaudio_drain(void *);
Static int	uaudio_query_encoding(void *, struct audio_encoding *);
Static void	uaudio_get_minmax_rates(int, const struct as_info *,
					const struct audio_params *,
					int, u_long *, u_long *);
Static int	uaudio_match_alt_sub(int, const struct as_info *,
				     const struct audio_params *, int, u_long);
Static int	uaudio_match_alt_chan(int, const struct as_info *,
				      struct audio_params *, int);
Static int	uaudio_match_alt(int, const struct as_info *,
				 struct audio_params *, int);
Static int	uaudio_set_params(void *, int, int, struct audio_params *,
				  struct audio_params *);
Static int	uaudio_round_blocksize(void *, int);
Static int	uaudio_trigger_output(void *, void *, void *, int,
		    void (*)(void *), void *, struct audio_params *);
Static int	uaudio_trigger_input (void *, void *, void *, int,
		    void (*)(void *), void *, struct audio_params *);
Static int	uaudio_halt_in_dma(void *);
Static int	uaudio_halt_out_dma(void *);
Static int	uaudio_getdev(void *, struct audio_device *);
Static int	uaudio_mixer_set_port(void *, mixer_ctrl_t *);
Static int	uaudio_mixer_get_port(void *, mixer_ctrl_t *);
Static int	uaudio_query_devinfo(void *, mixer_devinfo_t *);
Static int	uaudio_get_props(void *);

Static struct audio_hw_if uaudio_hw_if = {
	uaudio_open,
	uaudio_close,
	uaudio_drain,
	uaudio_query_encoding,
	uaudio_set_params,
	uaudio_round_blocksize,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	uaudio_halt_out_dma,
	uaudio_halt_in_dma,
	NULL,
	uaudio_getdev,
	NULL,
	uaudio_mixer_set_port,
	uaudio_mixer_get_port,
	uaudio_query_devinfo,
	NULL,
	NULL,
	NULL,
	NULL,
	uaudio_get_props,
	uaudio_trigger_output,
	uaudio_trigger_input,
	NULL,
};

Static struct audio_device uaudio_device = {
	"USB audio",
	"",
	"uaudio"
};

USB_DECLARE_DRIVER(uaudio);

USB_MATCH(uaudio)
{
	USB_MATCH_START(uaudio, uaa);
	usb_interface_descriptor_t *id;

	if (uaa->iface == NULL)
		return (UMATCH_NONE);

	id = usbd_get_interface_descriptor(uaa->iface);
	/* Trigger on the control interface. */
	if (id == NULL ||
	    id->bInterfaceClass != UICLASS_AUDIO ||
	    id->bInterfaceSubClass != UISUBCLASS_AUDIOCONTROL ||
	    (usbd_get_quirks(uaa->device)->uq_flags & UQ_BAD_AUDIO))
		return (UMATCH_NONE);

	return (UMATCH_IFACECLASS_IFACESUBCLASS);
}

USB_ATTACH(uaudio)
{
	USB_ATTACH_START(uaudio, sc, uaa);
	usb_interface_descriptor_t *id;
	usb_config_descriptor_t *cdesc;
	char devinfo[1024];
	usbd_status err;
	int i, j, found;

	usbd_devinfo(uaa->device, 0, devinfo, sizeof(devinfo));
	printf(": %s\n", devinfo);

	sc->sc_udev = uaa->device;

	cdesc = usbd_get_config_descriptor(sc->sc_udev);
	if (cdesc == NULL) {
		printf("%s: failed to get configuration descriptor\n",
		       USBDEVNAME(sc->sc_dev));
		USB_ATTACH_ERROR_RETURN;
	}

	err = uaudio_identify(sc, cdesc);
	if (err) {
		printf("%s: audio descriptors make no sense, error=%d\n",
		       USBDEVNAME(sc->sc_dev), err);
		USB_ATTACH_ERROR_RETURN;
	}

	sc->sc_ac_ifaceh = uaa->iface;
	/* Pick up the AS interface. */
	for (i = 0; i < uaa->nifaces; i++) {
		if (uaa->ifaces[i] == NULL)
			continue;
		id = usbd_get_interface_descriptor(uaa->ifaces[i]);
		if (id == NULL)
			continue;
		found = 0;
		for (j = 0; j < sc->sc_nalts; j++) {
			if (id->bInterfaceNumber ==
			    sc->sc_alts[j].idesc->bInterfaceNumber) {
				sc->sc_alts[j].ifaceh = uaa->ifaces[i];
				found = 1;
			}
		}
		if (found)
			uaa->ifaces[i] = NULL;
	}

	for (j = 0; j < sc->sc_nalts; j++) {
		if (sc->sc_alts[j].ifaceh == NULL) {
			printf("%s: alt %d missing AS interface(s)\n",
			    USBDEVNAME(sc->sc_dev), j);
			USB_ATTACH_ERROR_RETURN;
		}
	}

	printf("%s: audio rev %d.%02x\n", USBDEVNAME(sc->sc_dev),
	       sc->sc_audio_rev >> 8, sc->sc_audio_rev & 0xff);

	sc->sc_playchan.sc = sc->sc_recchan.sc = sc;
	sc->sc_playchan.altidx = -1;
	sc->sc_recchan.altidx = -1;

	if (usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_AU_NO_FRAC)
		sc->sc_altflags |= UA_NOFRAC;

#ifndef UAUDIO_DEBUG
	if (bootverbose)
#endif
		printf("%s: %d mixer controls\n", USBDEVNAME(sc->sc_dev),
		    sc->sc_nctls);

	usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev,
			   USBDEV(sc->sc_dev));

	DPRINTF(("uaudio_attach: doing audio_attach_mi\n"));
#if defined(__OpenBSD__)
	audio_attach_mi(&uaudio_hw_if, sc, &sc->sc_dev);
#else
	sc->sc_audiodev = audio_attach_mi(&uaudio_hw_if, sc, &sc->sc_dev);
#endif

	USB_ATTACH_SUCCESS_RETURN;
}

int
uaudio_activate(device_ptr_t self, enum devact act)
{
	struct uaudio_softc *sc = (struct uaudio_softc *)self;
	int rv = 0;

	switch (act) {
	case DVACT_ACTIVATE:
		return (EOPNOTSUPP);
		break;

	case DVACT_DEACTIVATE:
		if (sc->sc_audiodev != NULL)
			rv = config_deactivate(sc->sc_audiodev);
		sc->sc_dying = 1;
		break;
	}
	return (rv);
}

int
uaudio_detach(device_ptr_t self, int flags)
{
	struct uaudio_softc *sc = (struct uaudio_softc *)self;
	int rv = 0;

	/* Wait for outstanding requests to complete. */
	usbd_delay_ms(sc->sc_udev, UAUDIO_NCHANBUFS * UAUDIO_NFRAMES);

	if (sc->sc_audiodev != NULL)
		rv = config_detach(sc->sc_audiodev, flags);

	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev,
			   USBDEV(sc->sc_dev));

	return (rv);
}

int
uaudio_query_encoding(void *addr, struct audio_encoding *fp)
{
	struct uaudio_softc *sc = addr;
	int flags = sc->sc_altflags;
	int idx;

	if (sc->sc_dying)
		return (EIO);

	if (sc->sc_nalts == 0 || flags == 0)
		return (ENXIO);

	idx = fp->index;
	switch (idx) {
	case 0:
		strlcpy(fp->name, AudioEulinear, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_ULINEAR;
		fp->precision = 8;
		fp->flags = flags&HAS_8U ? 0 : AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 1:
		strlcpy(fp->name, AudioEmulaw, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_ULAW;
		fp->precision = 8;
		fp->flags = flags&HAS_MULAW ? 0 : AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 2:
		strlcpy(fp->name, AudioEalaw, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_ALAW;
		fp->precision = 8;
		fp->flags = flags&HAS_ALAW ? 0 : AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 3:
		strlcpy(fp->name, AudioEslinear, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_SLINEAR;
		fp->precision = 8;
		fp->flags = flags&HAS_8 ? 0 : AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 4:
		strlcpy(fp->name, AudioEslinear_le, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_SLINEAR_LE;
		fp->precision = 16;
		fp->flags = 0;
		return (0);
	case 5:
		strlcpy(fp->name, AudioEulinear_le, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_ULINEAR_LE;
		fp->precision = 16;
		fp->flags = AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 6:
		strlcpy(fp->name, AudioEslinear_be, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_SLINEAR_BE;
		fp->precision = 16;
		fp->flags = AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	case 7:
		strlcpy(fp->name, AudioEulinear_be, sizeof(fp->name));
		fp->encoding = AUDIO_ENCODING_ULINEAR_BE;
		fp->precision = 16;
		fp->flags = AUDIO_ENCODINGFLAG_EMULATED;
		return (0);
	default:
		return (EINVAL);
	}
}

const usb_interface_descriptor_t *
uaudio_find_iface(const char *buf, int size, int *offsp, int subtype)
{
	const usb_interface_descriptor_t *d;

	while (*offsp < size) {
		d = (const void *)(buf + *offsp);
		*offsp += d->bLength;
		if (d->bDescriptorType == UDESC_INTERFACE &&
		    d->bInterfaceClass == UICLASS_AUDIO &&
		    d->bInterfaceSubClass == subtype)
			return (d);
	}
	return (NULL);
}

void
uaudio_mixer_add_ctl(struct uaudio_softc *sc, struct mixerctl *mc)
{
	int res;
	size_t len = sizeof(*mc) * (sc->sc_nctls + 1);
	struct mixerctl *nmc = sc->sc_nctls == 0 ?
	    malloc(len, M_USBDEV, M_NOWAIT) :
	    realloc(sc->sc_ctls, len, M_USBDEV, M_NOWAIT);

	if (nmc == NULL) {
		printf("uaudio_mixer_add_ctl: no memory\n");
		return;
	}
	sc->sc_ctls = nmc;

	mc->delta = 0;
	if (mc->type != MIX_ON_OFF) {
		/* Determine min and max values. */
		mc->minval = uaudio_signext(mc->type,
			uaudio_get(sc, GET_MIN, UT_READ_CLASS_INTERFACE,
				   mc->wValue[0], mc->wIndex,
				   MIX_SIZE(mc->type)));
		mc->maxval = 1 + uaudio_signext(mc->type,
			uaudio_get(sc, GET_MAX, UT_READ_CLASS_INTERFACE,
				   mc->wValue[0], mc->wIndex,
				   MIX_SIZE(mc->type)));
		mc->mul = mc->maxval - mc->minval;
		if (mc->mul == 0)
			mc->mul = 1;
		res = uaudio_get(sc, GET_RES, UT_READ_CLASS_INTERFACE,
				 mc->wValue[0], mc->wIndex,
				 MIX_SIZE(mc->type));
		if (res > 0)
			mc->delta = (res * 255 + mc->mul/2) / mc->mul;
	} else {
		mc->minval = 0;
		mc->maxval = 1;
	}

	sc->sc_ctls[sc->sc_nctls++] = *mc;

#ifdef UAUDIO_DEBUG
	if (uaudiodebug > 2) {
		int i;
		DPRINTF(("uaudio_mixer_add_ctl: wValue=%04x",mc->wValue[0]));
		for (i = 1; i < mc->nchan; i++)
			DPRINTF((",%04x", mc->wValue[i]));
		DPRINTF((" wIndex=%04x type=%d name='%s' unit='%s' "
			 "min=%d max=%d\n",
			 mc->wIndex, mc->type, mc->ctlname, mc->ctlunit,
			 mc->minval, mc->maxval));
	}
#endif
}

void
uaudio_mixer_alias_ctl(struct uaudio_softc *sc, struct mixerctl *mc,
		     const char *name)
{
	/* XXX mark as alias? */
	strlcpy(mc->ctlname, name, sizeof(mc->ctlname));
	uaudio_mixer_add_ctl(sc, mc);
}

char *
uaudio_id_name(struct uaudio_softc *sc, const usb_descriptor_t **dps, int id)
{
	static char buf[32];
	snprintf(buf, sizeof(buf), "i%d", id);
	return (buf);
}

struct usb_audio_cluster
uaudio_get_cluster(int id, const usb_descriptor_t **dps)
{
	struct usb_audio_cluster r;
	const usb_descriptor_t *dp;
	int i;

	for (i = 0; i < 25; i++) { /* avoid infinite loops */
		dp = dps[id];
		if (dp == 0)
			goto bad;
		switch (dp->bDescriptorSubtype) {
		case UDESCSUB_AC_INPUT:
#define p ((const struct usb_audio_input_terminal *)dp)
			r.bNrChannels = p->bNrChannels;
			USETW(r.wChannelConfig, UGETW(p->wChannelConfig));
			r.iChannelNames = p->iChannelNames;
#undef p
			return (r);
		case UDESCSUB_AC_OUTPUT:
#define p ((const struct usb_audio_output_terminal *)dp)
			id = p->bSourceId;
#undef p
			break;
		case UDESCSUB_AC_MIXER:
#define p ((const struct usb_audio_mixer_unit *)dp)
			r = *(struct usb_audio_cluster *)
				&p->baSourceId[p->bNrInPins];
#undef p
			return (r);
		case UDESCSUB_AC_SELECTOR:
			/* XXX This is not really right */
#define p ((const struct usb_audio_selector_unit *)dp)
			id = p->baSourceId[0];
#undef p
			break;
		case UDESCSUB_AC_FEATURE:
#define p ((const struct usb_audio_feature_unit *)dp)
			id = p->bSourceId;
#undef p
			break;
		case UDESCSUB_AC_PROCESSING:
#define p ((const struct usb_audio_processing_unit *)dp)
			r = *(struct usb_audio_cluster *)
				&p->baSourceId[p->bNrInPins];
#undef p
			return (r);
		case UDESCSUB_AC_EXTENSION:
#define p ((const struct usb_audio_extension_unit *)dp)
			r = *(struct usb_audio_cluster *)
				&p->baSourceId[p->bNrInPins];
#undef p
			return (r);
		default:
			goto bad;
		}
	}
 bad:
	printf("uaudio_get_cluster: bad data\n");
	memset(&r, 0, sizeof r);
	return (r);

}

void
uaudio_add_input(struct uaudio_softc *sc, const usb_descriptor_t *v,
		 const usb_descriptor_t **dps)
{
#ifdef UAUDIO_DEBUG
	const struct usb_audio_input_terminal *d =
		(const struct usb_audio_input_terminal *)v;

	DPRINTFN(2,("uaudio_add_input: bTerminalId=%d wTerminalType=0x%04x "
		    "bAssocTerminal=%d bNrChannels=%d wChannelConfig=%d "
		    "iChannelNames=%d iTerminal=%d\n",
		    d->bTerminalId, UGETW(d->wTerminalType), d->bAssocTerminal,
		    d->bNrChannels, UGETW(d->wChannelConfig),
		    d->iChannelNames, d->iTerminal));
#endif
}

void
uaudio_add_output(struct uaudio_softc *sc, const usb_descriptor_t *v,
		  const usb_descriptor_t **dps)
{
#ifdef UAUDIO_DEBUG
	const struct usb_audio_output_terminal *d =
		(const struct usb_audio_output_terminal *)v;

	DPRINTFN(2,("uaudio_add_output: bTerminalId=%d wTerminalType=0x%04x "
		    "bAssocTerminal=%d bSourceId=%d iTerminal=%d\n",
		    d->bTerminalId, UGETW(d->wTerminalType), d->bAssocTerminal,
		    d->bSourceId, d->iTerminal));
#endif
}

void
uaudio_add_mixer(struct uaudio_softc *sc, const usb_descriptor_t *v,
		 const usb_descriptor_t **dps)
{
	const struct usb_audio_mixer_unit *d = (const struct usb_audio_mixer_unit *)v;
	struct usb_audio_mixer_unit_1 *d1;
	int c, chs, ichs, ochs, i, o, bno, p, mo, mc, k;
	uByte *bm;
	struct mixerctl mix;

	DPRINTFN(2,("uaudio_add_mixer: bUnitId=%d bNrInPins=%d\n",
		    d->bUnitId, d->bNrInPins));

	/* Compute the number of input channels */
	ichs = 0;
	for (i = 0; i < d->bNrInPins; i++)
		ichs += uaudio_get_cluster(d->baSourceId[i], dps).bNrChannels;

	/* and the number of output channels */
	d1 = (struct usb_audio_mixer_unit_1 *)&d->baSourceId[d->bNrInPins];
	ochs = d1->bNrChannels;
	DPRINTFN(2,("uaudio_add_mixer: ichs=%d ochs=%d\n", ichs, ochs));

	bm = d1->bmControls;
	mix.wIndex = MAKE(d->bUnitId, sc->sc_ac_iface);
	mix.class = -1;
	mix.type = MIX_SIGNED_16;
	mix.ctlunit = AudioNvolume;
#define BIT(bno) ((bm[bno / 8] >> (7 - bno % 8)) & 1)
	for (p = i = 0; i < d->bNrInPins; i++) {
		chs = uaudio_get_cluster(d->baSourceId[i], dps).bNrChannels;
		mc = 0;
		for (c = 0; c < chs; c++) {
			mo = 0;
			for (o = 0; o < ochs; o++) {
				bno = (p + c) * ochs + o;
				if (BIT(bno))
					mo++;
			}
			if (mo == 1)
				mc++;
		}
		if (mc == chs && chs <= MIX_MAX_CHAN) {
			k = 0;
			for (c = 0; c < chs; c++)
				for (o = 0; o < ochs; o++) {
					bno = (p + c) * ochs + o;
					if (BIT(bno))
						mix.wValue[k++] =
							MAKE(p+c+1, o+1);
				}
			snprintf(mix.ctlname, sizeof(mix.ctlname), "mix%d-%s",
			    d->bUnitId, uaudio_id_name(sc, dps,
			    d->baSourceId[i]));
			mix.nchan = chs;
			uaudio_mixer_add_ctl(sc, &mix);
		} else {
			/* XXX */
		}
#undef BIT
		p += chs;
	}

}

void
uaudio_add_selector(struct uaudio_softc *sc, const usb_descriptor_t *v,
		    const usb_descriptor_t **dps)
{
#ifdef UAUDIO_DEBUG
	const struct usb_audio_selector_unit *d =
		(const struct usb_audio_selector_unit *)v;

	DPRINTFN(2,("uaudio_add_selector: bUnitId=%d bNrInPins=%d\n",
		    d->bUnitId, d->bNrInPins));
#endif
	printf("uaudio_add_selector: NOT IMPLEMENTED\n");
}

void
uaudio_add_feature(struct uaudio_softc *sc, const usb_descriptor_t *v,
		   const usb_descriptor_t **dps)
{
	const struct usb_audio_feature_unit *d
		= (const struct usb_audio_feature_unit *)v;
	uByte *ctls = d->bmaControls;
	int ctlsize = d->bControlSize;
	int nchan = (d->bLength - 7) / ctlsize;
	int srcId = d->bSourceId;
	u_int fumask, mmask, cmask;
	struct mixerctl mix;
	int chan, ctl, i, unit;

#define GET(i) (ctls[(i)*ctlsize] | \
		(ctlsize > 1 ? ctls[(i)*ctlsize+1] << 8 : 0))

	mmask = GET(0);
	/* Figure out what we can control */
	for (cmask = 0, chan = 1; chan < nchan; chan++) {
		DPRINTFN(9,("uaudio_add_feature: chan=%d mask=%x\n",
			    chan, GET(chan)));
		cmask |= GET(chan);
	}

	DPRINTFN(1,("uaudio_add_feature: bUnitId=%d bSourceId=%d, "
		    "%d channels, mmask=0x%04x, cmask=0x%04x\n",
		    d->bUnitId, srcId, nchan, mmask, cmask));

	if (nchan > MIX_MAX_CHAN)
		nchan = MIX_MAX_CHAN;
	unit = d->bUnitId;
	mix.wIndex = MAKE(unit, sc->sc_ac_iface);
	for (ctl = MUTE_CONTROL; ctl < LOUDNESS_CONTROL; ctl++) {
		fumask = FU_MASK(ctl);
		DPRINTFN(4,("uaudio_add_feature: ctl=%d fumask=0x%04x\n",
			    ctl, fumask));
		if (mmask & fumask) {
			mix.nchan = 1;
			mix.wValue[0] = MAKE(ctl, 0);
		} else if (cmask & fumask) {
			mix.nchan = nchan - 1;
			for (i = 1; i < nchan; i++) {
				if (GET(i) & fumask)
					mix.wValue[i-1] = MAKE(ctl, i);
				else
					mix.wValue[i-1] = -1;
			}
		} else {
			continue;
		}
#undef GET
		mix.class = UAC_OUTPUT;	/* XXX we don't really know this */
		switch (ctl) {
		case MUTE_CONTROL:
			mix.type = MIX_ON_OFF;
			mix.ctlunit = "";
			uaudio_mixer_alias_ctl(sc, &mix, AudioNmute);
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNmute);
			break;
		case VOLUME_CONTROL:
			mix.type = MIX_SIGNED_16;
			mix.ctlunit = AudioNvolume;
			uaudio_mixer_alias_ctl(sc, &mix, AudioNmaster);
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNmaster);
			break;
		case BASS_CONTROL:
			mix.type = MIX_SIGNED_8;
			mix.ctlunit = AudioNbass;
			uaudio_mixer_alias_ctl(sc, &mix, AudioNbass);
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNbass);
			break;
		case MID_CONTROL:
			mix.type = MIX_SIGNED_8;
			mix.ctlunit = AudioNmid;
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNmid);
			break;
		case TREBLE_CONTROL:
			mix.type = MIX_SIGNED_8;
			mix.ctlunit = AudioNtreble;
			uaudio_mixer_alias_ctl(sc, &mix, AudioNtreble);
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNtreble);
			break;
		case GRAPHIC_EQUALIZER_CONTROL:
			continue; /* XXX don't add anything */
			break;
		case AGC_CONTROL:
			mix.type = MIX_ON_OFF;
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNagc);
			mix.ctlunit = "";
			break;
		case DELAY_CONTROL:
			mix.type = MIX_UNSIGNED_16;
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNdelay);
			mix.ctlunit = "4 ms";
			break;
		case BASS_BOOST_CONTROL:
			mix.type = MIX_ON_OFF;
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNbassboost);
			mix.ctlunit = "";
			break;
		case LOUDNESS_CONTROL:
			mix.type = MIX_ON_OFF;
			snprintf(mix.ctlname, sizeof(mix.ctlname),
			    "fea%d-%s-%s", unit, uaudio_id_name(sc, dps, srcId),
			    AudioNloudness);
			mix.ctlunit = "";
			break;
		}
		uaudio_mixer_add_ctl(sc, &mix);
	}
}

void
uaudio_add_processing_updown(struct uaudio_softc *sc,
			     const usb_descriptor_t *v,
			     const usb_descriptor_t **dps)
{
	const struct usb_audio_processing_unit *d =
	    (const struct usb_audio_processing_unit *)v;
	const struct usb_audio_processing_unit_1 *d1 =
	    (const struct usb_audio_processing_unit_1 *)&d->baSourceId[d->bNrInPins];
	const struct usb_audio_processing_unit_updown *ud =
	    (const struct usb_audio_processing_unit_updown *)
		&d1->bmControls[d1->bControlSize];
	struct mixerctl mix;
	int i;

	DPRINTFN(2,("uaudio_add_processing_updown: bUnitId=%d bNrModes=%d\n",
		    d->bUnitId, ud->bNrModes));

	if (!(d1->bmControls[0] & UA_PROC_MASK(UD_MODE_SELECT_CONTROL))) {
		DPRINTF(("uaudio_add_processing_updown: no mode select\n"));
		return;
	}

	mix.wIndex = MAKE(d->bUnitId, sc->sc_ac_iface);
	mix.nchan = 1;
	mix.wValue[0] = MAKE(UD_MODE_SELECT_CONTROL, 0);
	mix.class = -1;
	mix.type = MIX_ON_OFF;	/* XXX */
	mix.ctlunit = "";
	snprintf(mix.ctlname, sizeof(mix.ctlname), "pro%d-mode", d->bUnitId);

	for (i = 0; i < ud->bNrModes; i++) {
		DPRINTFN(2,("uaudio_add_processing_updown: i=%d bm=0x%x\n",
			    i, UGETW(ud->waModes[i])));
		/* XXX */
	}
	uaudio_mixer_add_ctl(sc, &mix);
}

void
uaudio_add_processing(struct uaudio_softc *sc, const usb_descriptor_t *v,
		      const usb_descriptor_t **dps)
{
	const struct usb_audio_processing_unit *d =
	    (const struct usb_audio_processing_unit *)v;
	const struct usb_audio_processing_unit_1 *d1 =
	    (const struct usb_audio_processing_unit_1 *)&d->baSourceId[d->bNrInPins];
	int ptype = UGETW(d->wProcessType);
	struct mixerctl mix;

	DPRINTFN(2,("uaudio_add_processing: wProcessType=%d bUnitId=%d "
		    "bNrInPins=%d\n", ptype, d->bUnitId, d->bNrInPins));

	if (d1->bmControls[0] & UA_PROC_ENABLE_MASK) {
		mix.wIndex = MAKE(d->bUnitId, sc->sc_ac_iface);
		mix.nchan = 1;
		mix.wValue[0] = MAKE(XX_ENABLE_CONTROL, 0);
		mix.class = -1;
		mix.type = MIX_ON_OFF;
		mix.ctlunit = "";
		snprintf(mix.ctlname, sizeof(mix.ctlname), "pro%d.%d-enable",
		    d->bUnitId, ptype);
		uaudio_mixer_add_ctl(sc, &mix);
	}

	switch(ptype) {
	case UPDOWNMIX_PROCESS:
		uaudio_add_processing_updown(sc, v, dps);
		break;
	case DOLBY_PROLOGIC_PROCESS:
	case P3D_STEREO_EXTENDER_PROCESS:
	case REVERBATION_PROCESS:
	case CHORUS_PROCESS:
	case DYN_RANGE_COMP_PROCESS:
	default:
#ifdef UAUDIO_DEBUG
		printf("uaudio_add_processing: unit %d, type=%d not impl.\n",
		       d->bUnitId, ptype);
#endif
		break;
	}
}

void
uaudio_add_extension(struct uaudio_softc *sc, const usb_descriptor_t *v,
		     const usb_descriptor_t **dps)
{
	const struct usb_audio_extension_unit *d =
	    (const struct usb_audio_extension_unit *)v;
	const struct usb_audio_extension_unit_1 *d1 =
	    (const struct usb_audio_extension_unit_1 *)&d->baSourceId[d->bNrInPins];
	struct mixerctl mix;

	DPRINTFN(2,("uaudio_add_extension: bUnitId=%d bNrInPins=%d\n",
		    d->bUnitId, d->bNrInPins));

	if (usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_AU_NO_XU)
		return;

	if (d1->bmControls[0] & UA_EXT_ENABLE_MASK) {
		mix.wIndex = MAKE(d->bUnitId, sc->sc_ac_iface);
		mix.nchan = 1;
		mix.wValue[0] = MAKE(UA_EXT_ENABLE, 0);
		mix.class = -1;
		mix.type = MIX_ON_OFF;
		mix.ctlunit = "";
		snprintf(mix.ctlname, sizeof(mix.ctlname), "ext%d-enable",
		    d->bUnitId);
		uaudio_mixer_add_ctl(sc, &mix);
	}
}

usbd_status
uaudio_identify(struct uaudio_softc *sc, const usb_config_descriptor_t *cdesc)
{
	usbd_status err;

	err = uaudio_identify_ac(sc, cdesc);
	if (err)
		return (err);
	return (uaudio_identify_as(sc, cdesc));
}

void
uaudio_add_alt(struct uaudio_softc *sc, const struct as_info *ai)
{
	size_t len = sizeof(*ai) * (sc->sc_nalts + 1);
	struct as_info *nai = (sc->sc_nalts == 0) ?
	    malloc(len, M_USBDEV, M_NOWAIT) :
	    realloc(sc->sc_alts, len, M_USBDEV, M_NOWAIT);

	if (nai == NULL) {
		printf("uaudio_add_alt: no memory\n");
		return;
	}

	sc->sc_alts = nai;
	DPRINTFN(2,("uaudio_add_alt: adding alt=%d, enc=%d\n",
		    ai->alt, ai->encoding));
	sc->sc_alts[sc->sc_nalts++] = *ai;
}

usbd_status
uaudio_process_as(struct uaudio_softc *sc, const char *buf, int *offsp,
		  int size, const usb_interface_descriptor_t *id)
#define offs (*offsp)
{
	const struct usb_audio_streaming_interface_descriptor *asid;
	const struct usb_audio_streaming_type1_descriptor *asf1d;
	const usb_endpoint_descriptor_audio_t *ed;
	const struct usb_audio_streaming_endpoint_descriptor *sed;
	int format, chan, prec, enc;
	int dir, type;
	struct as_info ai;
	const char *format_str;

	asid = (const void *)(buf + offs);
	if (asid->bDescriptorType != UDESC_CS_INTERFACE ||
	    asid->bDescriptorSubtype != AS_GENERAL)
		return (USBD_INVAL);
	DPRINTF(("uaudio_process_as: asid: bTerminakLink=%d wFormatTag=%d\n",
		 asid->bTerminalLink, UGETW(asid->wFormatTag)));
	offs += asid->bLength;
	if (offs > size)
		return (USBD_INVAL);

	asf1d = (const void *)(buf + offs);
	if (asf1d->bDescriptorType != UDESC_CS_INTERFACE ||
	    asf1d->bDescriptorSubtype != FORMAT_TYPE)
		return (USBD_INVAL);
	offs += asf1d->bLength;
	if (offs > size)
		return (USBD_INVAL);

	if (asf1d->bFormatType != FORMAT_TYPE_I) {
		printf("%s: ignored setting with type %d format\n",
		       USBDEVNAME(sc->sc_dev), UGETW(asid->wFormatTag));
		return (USBD_NORMAL_COMPLETION);
	}

	ed = (const void *)(buf + offs);
	if (ed->bDescriptorType != UDESC_ENDPOINT)
		return (USBD_INVAL);
	DPRINTF(("uaudio_process_as: endpoint bLength=%d bDescriptorType=%d "
		 "bEndpointAddress=%d bmAttributes=0x%x wMaxPacketSize=%d "
		 "bInterval=%d bRefresh=%d bSynchAddress=%d\n",
		 ed->bLength, ed->bDescriptorType, ed->bEndpointAddress,
		 ed->bmAttributes, UGETW(ed->wMaxPacketSize),
		 ed->bInterval, ed->bRefresh, ed->bSynchAddress));
	offs += ed->bLength;
	if (offs > size)
		return (USBD_INVAL);
	if (UE_GET_XFERTYPE(ed->bmAttributes) != UE_ISOCHRONOUS)
		return (USBD_INVAL);

	dir = UE_GET_DIR(ed->bEndpointAddress);
	type = UE_GET_ISO_TYPE(ed->bmAttributes);
	if ((usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_AU_INP_ASYNC) &&
	    dir == UE_DIR_IN && type == UE_ISO_ADAPT)
		type = UE_ISO_ASYNC;

	/* We can't handle endpoints that need a sync pipe yet. */
	if (dir == UE_DIR_IN && type == UE_ISO_ADAPT) {
		printf("%s: ignored input endpoint of type adaptive\n",
		       USBDEVNAME(sc->sc_dev));
		return (USBD_NORMAL_COMPLETION);
	}
	if (dir != UE_DIR_IN && type == UE_ISO_ASYNC) {
		printf("%s: ignored output endpoint of type async\n",
		       USBDEVNAME(sc->sc_dev));
		return (USBD_NORMAL_COMPLETION);
	}

	sed = (const void *)(buf + offs);
	if (sed->bDescriptorType != UDESC_CS_ENDPOINT ||
	    sed->bDescriptorSubtype != AS_GENERAL)
		return (USBD_INVAL);
	offs += sed->bLength;
	if (offs > size)
		return (USBD_INVAL);

	format = UGETW(asid->wFormatTag);
	chan = asf1d->bNrChannels;
	prec = asf1d->bBitResolution;
	if (prec != 8 && prec != 16 && prec != 24) {
		printf("%s: ignored setting with precision %d\n",
		       USBDEVNAME(sc->sc_dev), prec);
		return (USBD_NORMAL_COMPLETION);
	}
	switch (format) {
	case UA_FMT_PCM:
		if (prec == 8) {
			sc->sc_altflags |= HAS_8;
		} else if (prec == 16) {
			sc->sc_altflags |= HAS_16;
		} else if (prec == 24) {
			sc->sc_altflags |= HAS_24;
		}
		enc = AUDIO_ENCODING_SLINEAR_LE;
		format_str = "pcm";
		break;
	case UA_FMT_PCM8:
		enc = AUDIO_ENCODING_ULINEAR_LE;
		sc->sc_altflags |= HAS_8U;
		format_str = "pcm8";
		break;
	case UA_FMT_ALAW:
		enc = AUDIO_ENCODING_ALAW;
		sc->sc_altflags |= HAS_ALAW;
		format_str = "alaw";
		break;
	case UA_FMT_MULAW:
		enc = AUDIO_ENCODING_ULAW;
		sc->sc_altflags |= HAS_MULAW;
		format_str = "mulaw";
		break;
	default:
		printf("%s: ignored setting with format %d\n",
		       USBDEVNAME(sc->sc_dev), format);
		return (USBD_NORMAL_COMPLETION);
	}
#ifdef UAUDIO_DEBUG
	printf("%s: %s: %dch, %d/%dbit, %s,", USBDEVNAME(sc->sc_dev),
	       dir == UE_DIR_IN ? "recording" : "playback",
	       chan, prec, asf1d->bSubFrameSize * 8, format_str);
	if (asf1d->bSamFreqType == UA_SAMP_CONTNUOUS) {
		printf(" %d-%dHz\n", UA_SAMP_LO(asf1d), UA_SAMP_HI(asf1d));
	} else {
		int r;
		printf(" %d", UA_GETSAMP(asf1d, 0));
		for (r = 1; r < asf1d->bSamFreqType; r++)
			printf(",%d", UA_GETSAMP(asf1d, r));
		printf("Hz\n");
	}
#endif
	ai.alt = id->bAlternateSetting;
	ai.encoding = enc;
	ai.attributes = sed->bmAttributes;
	ai.idesc = id;
	ai.edesc = ed;
	ai.asf1desc = asf1d;
	ai.sc_busy = 0;
	uaudio_add_alt(sc, &ai);
#ifdef UAUDIO_DEBUG
	if (ai.attributes & UA_SED_FREQ_CONTROL)
		DPRINTFN(1, ("uaudio_process_as:  FREQ_CONTROL\n"));
	if (ai.attributes & UA_SED_PITCH_CONTROL)
		DPRINTFN(1, ("uaudio_process_as:  PITCH_CONTROL\n"));
#endif
	sc->sc_mode |= (dir == UE_DIR_OUT) ? AUMODE_PLAY : AUMODE_RECORD;

	return (USBD_NORMAL_COMPLETION);
}
#undef offs

usbd_status
uaudio_identify_as(struct uaudio_softc *sc,
		   const usb_config_descriptor_t *cdesc)
{
	const usb_interface_descriptor_t *id;
	const char *buf;
	int size, offs;

	size = UGETW(cdesc->wTotalLength);
	buf = (const char *)cdesc;

	/* Locate the AudioStreaming interface descriptor. */
	offs = 0;
	id = uaudio_find_iface(buf, size, &offs, UISUBCLASS_AUDIOSTREAM);
	if (id == NULL)
		return (USBD_INVAL);

	/* Loop through all the alternate settings. */
	while (offs <= size) {
		DPRINTFN(2, ("uaudio_identify: interface %d\n",
		    id->bInterfaceNumber));
		switch (id->bNumEndpoints) {
		case 0:
			DPRINTFN(2, ("uaudio_identify: AS null alt=%d\n",
				     id->bAlternateSetting));
			sc->sc_nullalt = id->bAlternateSetting;
			break;
		case 1:
			uaudio_process_as(sc, buf, &offs, size, id);
			break;
		default:
			printf("%s: ignored audio interface with %d "
			       "endpoints\n",
			       USBDEVNAME(sc->sc_dev), id->bNumEndpoints);
			break;
		}
		id = uaudio_find_iface(buf, size, &offs,UISUBCLASS_AUDIOSTREAM);
		if (id == NULL)
			break;
	}
	if (offs > size)
		return (USBD_INVAL);
	DPRINTF(("uaudio_identify_as: %d alts available\n", sc->sc_nalts));

	if (sc->sc_mode == 0) {
		printf("%s: no usable endpoint found\n",
		       USBDEVNAME(sc->sc_dev));
		return (USBD_INVAL);
	}

	return (USBD_NORMAL_COMPLETION);
}

usbd_status
uaudio_identify_ac(struct uaudio_softc *sc, const usb_config_descriptor_t *cdesc)
{
	const usb_interface_descriptor_t *id;
	const struct usb_audio_control_descriptor *acdp;
	const usb_descriptor_t *dp, *dps[256];
	const char *buf, *ibuf, *ibufend;
	int size, offs, aclen, ndps, i;

	size = UGETW(cdesc->wTotalLength);
	buf = (char *)cdesc;

	/* Locate the AudioControl interface descriptor. */
	offs = 0;
	id = uaudio_find_iface(buf, size, &offs, UISUBCLASS_AUDIOCONTROL);
	if (id == NULL)
		return (USBD_INVAL);
	if (offs + sizeof *acdp > size)
		return (USBD_INVAL);
	sc->sc_ac_iface = id->bInterfaceNumber;
	DPRINTFN(2,("uaudio_identify: AC interface is %d\n", sc->sc_ac_iface));

	/* A class-specific AC interface header should follow. */
	ibuf = buf + offs;
	acdp = (const struct usb_audio_control_descriptor *)ibuf;
	if (acdp->bDescriptorType != UDESC_CS_INTERFACE ||
	    acdp->bDescriptorSubtype != UDESCSUB_AC_HEADER)
		return (USBD_INVAL);
	aclen = UGETW(acdp->wTotalLength);
	if (offs + aclen > size)
		return (USBD_INVAL);

	if (!(usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_BAD_ADC) &&
	     UGETW(acdp->bcdADC) != UAUDIO_VERSION)
		return (USBD_INVAL);

	sc->sc_audio_rev = UGETW(acdp->bcdADC);
	DPRINTFN(2,("uaudio_identify: found AC header, vers=%03x, len=%d\n",
		 sc->sc_audio_rev, aclen));

	sc->sc_nullalt = -1;

	/* Scan through all the AC specific descriptors */
	ibufend = ibuf + aclen;
	dp = (usb_descriptor_t *)ibuf;
	ndps = 0;
	memset(dps, 0, sizeof dps);
	for (;;) {
		ibuf += dp->bLength;
		if (ibuf >= ibufend)
			break;
		dp = (usb_descriptor_t *)ibuf;
		if (ibuf + dp->bLength > ibufend)
			return (USBD_INVAL);
		if (dp->bDescriptorType != UDESC_CS_INTERFACE) {
			printf("uaudio_identify: skip desc type=0x%02x\n",
			       dp->bDescriptorType);
			continue;
		}
		i = ((struct usb_audio_input_terminal *)dp)->bTerminalId;
		dps[i] = dp;
		if (i > ndps)
			ndps = i;
	}
	ndps++;

	for (i = 0; i < ndps; i++) {
		dp = dps[i];
		if (dp == NULL)
			continue;
		DPRINTF(("uaudio_identify: subtype=%d\n",
			 dp->bDescriptorSubtype));
		switch (dp->bDescriptorSubtype) {
		case UDESCSUB_AC_HEADER:
			printf("uaudio_identify: unexpected AC header\n");
			break;
		case UDESCSUB_AC_INPUT:
			uaudio_add_input(sc, dp, dps);
			break;
		case UDESCSUB_AC_OUTPUT:
			uaudio_add_output(sc, dp, dps);
			break;
		case UDESCSUB_AC_MIXER:
			uaudio_add_mixer(sc, dp, dps);
			break;
		case UDESCSUB_AC_SELECTOR:
			uaudio_add_selector(sc, dp, dps);
			break;
		case UDESCSUB_AC_FEATURE:
			uaudio_add_feature(sc, dp, dps);
			break;
		case UDESCSUB_AC_PROCESSING:
			uaudio_add_processing(sc, dp, dps);
			break;
		case UDESCSUB_AC_EXTENSION:
			uaudio_add_extension(sc, dp, dps);
			break;
		default:
			printf("uaudio_identify: bad AC desc subtype=0x%02x\n",
			       dp->bDescriptorSubtype);
			break;
		}
	}
	return (USBD_NORMAL_COMPLETION);
}

int
uaudio_query_devinfo(void *addr, mixer_devinfo_t *mi)
{
	struct uaudio_softc *sc = addr;
	struct mixerctl *mc;
	int n, nctls;

	DPRINTFN(2,("uaudio_query_devinfo: index=%d\n", mi->index));
	if (sc->sc_dying)
		return (EIO);

	n = mi->index;
	nctls = sc->sc_nctls;

	switch (n) {
	case UAC_OUTPUT:
		mi->type = AUDIO_MIXER_CLASS;
		mi->mixer_class = UAC_OUTPUT;
		mi->next = mi->prev = AUDIO_MIXER_LAST;
		strlcpy(mi->label.name, AudioCoutputs, sizeof(mi->label.name));
		return (0);
	case UAC_INPUT:
		mi->type = AUDIO_MIXER_CLASS;
		mi->mixer_class = UAC_INPUT;
		mi->next = mi->prev = AUDIO_MIXER_LAST;
		strlcpy(mi->label.name, AudioCinputs, sizeof(mi->label.name));
		return (0);
	case UAC_EQUAL:
		mi->type = AUDIO_MIXER_CLASS;
		mi->mixer_class = UAC_EQUAL;
		mi->next = mi->prev = AUDIO_MIXER_LAST;
		strlcpy(mi->label.name, AudioCequalization,
		    sizeof(mi->label.name));
		return (0);
	default:
		break;
	}

	n -= UAC_NCLASSES;
	if (n < 0 || n >= nctls)
		return (ENXIO);

	mc = &sc->sc_ctls[n];
	strlcpy(mi->label.name, mc->ctlname, sizeof(mi->label.name));
	mi->mixer_class = mc->class;
	mi->next = mi->prev = AUDIO_MIXER_LAST;	/* XXX */
	switch (mc->type) {
	case MIX_ON_OFF:
		mi->type = AUDIO_MIXER_ENUM;
		mi->un.e.num_mem = 2;
		strlcpy(mi->un.e.member[0].label.name, AudioNoff,
		    sizeof(mi->un.e.member[0].label.name));
		mi->un.e.member[0].ord = 0;
		strlcpy(mi->un.e.member[1].label.name, AudioNon,
		    sizeof(mi->un.e.member[1].label.name));
		mi->un.e.member[1].ord = 1;
		break;
	default:
		mi->type = AUDIO_MIXER_VALUE;
		strncpy(mi->un.v.units.name, mc->ctlunit, MAX_AUDIO_DEV_LEN);
		mi->un.v.num_channels = mc->nchan;
		mi->un.v.delta = mc->delta;
		break;
	}
	return (0);
}

int
uaudio_open(void *addr, int flags)
{
	struct uaudio_softc *sc = addr;

	DPRINTF(("uaudio_open: sc=%p\n", sc));
	if (sc->sc_dying)
		return (EIO);

	if ((flags & FWRITE) && !(sc->sc_mode & AUMODE_PLAY))
		return (EACCES);
	if ((flags & FREAD) && !(sc->sc_mode & AUMODE_RECORD))
		return (EACCES);

	return (0);
}

/*
 * Close function is called at splaudio().
 */
void
uaudio_close(void *addr)
{
}

int
uaudio_drain(void *addr)
{
	struct uaudio_softc *sc = addr;

	usbd_delay_ms(sc->sc_udev, UAUDIO_NCHANBUFS * UAUDIO_NFRAMES);

	return (0);
}

int
uaudio_halt_out_dma(void *addr)
{
	struct uaudio_softc *sc = addr;

	DPRINTF(("uaudio_halt_out_dma: enter\n"));
	if (sc->sc_playchan.pipe != NULL) {
		uaudio_chan_close(sc, &sc->sc_playchan);
		sc->sc_playchan.pipe = NULL;
		uaudio_chan_free_buffers(sc, &sc->sc_playchan);
		sc->sc_playchan.intr = NULL;
	}
	return (0);
}

int
uaudio_halt_in_dma(void *addr)
{
	struct uaudio_softc *sc = addr;

	DPRINTF(("uaudio_halt_in_dma: enter\n"));
	if (sc->sc_recchan.pipe != NULL) {
		uaudio_chan_close(sc, &sc->sc_recchan);
		sc->sc_recchan.pipe = NULL;
		uaudio_chan_free_buffers(sc, &sc->sc_recchan);
		sc->sc_recchan.intr = NULL;
	}
	return (0);
}

int
uaudio_getdev(void *addr, struct audio_device *retp)
{
	struct uaudio_softc *sc = addr;

	DPRINTF(("uaudio_mixer_getdev:\n"));
	if (sc->sc_dying)
		return (EIO);

	*retp = uaudio_device;
	return (0);
}

/*
 * Make sure the block size is large enough to hold all outstanding transfers.
 */
int
uaudio_round_blocksize(void *addr, int blk)
{
	struct uaudio_softc *sc = addr;
	int bpf;

	DPRINTF(("uaudio_round_blocksize: p.bpf=%d r.bpf=%d\n",
		 sc->sc_playchan.bytes_per_frame,
		 sc->sc_recchan.bytes_per_frame));
	if (sc->sc_playchan.bytes_per_frame > sc->sc_recchan.bytes_per_frame) {
		bpf = sc->sc_playchan.bytes_per_frame
		    + sc->sc_playchan.sample_size;
	} else {
		bpf = sc->sc_recchan.bytes_per_frame
		    + sc->sc_recchan.sample_size;
	}
	/* XXX */
	bpf *= UAUDIO_NFRAMES * UAUDIO_NCHANBUFS;

	bpf = (bpf + 15) &~ 15;

	if (blk < bpf)
		blk = bpf;

#ifdef DIAGNOSTIC
	if (blk <= 0) {
		printf("uaudio_round_blocksize: blk=%d\n", blk);
		blk = 512;
	}
#endif

	DPRINTFN(1,("uaudio_round_blocksize: blk=%d\n", blk));
	return (blk);
}

int
uaudio_get_props(void *addr)
{
	return (AUDIO_PROP_FULLDUPLEX | AUDIO_PROP_INDEPENDENT);

}

int
uaudio_get(struct uaudio_softc *sc, int which, int type, int wValue,
	   int wIndex, int len)
{
	usb_device_request_t req;
	u_int8_t data[4];
	usbd_status err;
	int val;

	if (wValue == -1)
		return (0);

	req.bmRequestType = type;
	req.bRequest = which;
	USETW(req.wValue, wValue);
	USETW(req.wIndex, wIndex);
	USETW(req.wLength, len);
	DPRINTFN(2,("uaudio_get: type=0x%02x req=0x%02x wValue=0x%04x "
		    "wIndex=0x%04x len=%d\n",
		    type, which, wValue, wIndex, len));
	err = usbd_do_request(sc->sc_udev, &req, data);
	if (err) {
		DPRINTF(("uaudio_get: err=%s\n", usbd_errstr(err)));
		return (-1);
	}
	switch (len) {
	case 1:
		val = data[0];
		break;
	case 2:
		val = data[0] | (data[1] << 8);
		break;
	default:
		DPRINTF(("uaudio_get: bad length=%d\n", len));
		return (-1);
	}
	DPRINTFN(2,("uaudio_get: val=%d\n", val));
	return (val);
}

void
uaudio_set(struct uaudio_softc *sc, int which, int type, int wValue,
	   int wIndex, int len, int val)
{
	usb_device_request_t req;
	u_int8_t data[4];
	usbd_status err;

	if (wValue == -1)
		return;

	req.bmRequestType = type;
	req.bRequest = which;
	USETW(req.wValue, wValue);
	USETW(req.wIndex, wIndex);
	USETW(req.wLength, len);
	switch (len) {
	case 1:
		data[0] = val;
		break;
	case 2:
		data[0] = val;
		data[1] = val >> 8;
		break;
	default:
		return;
	}
	DPRINTFN(2,("uaudio_set: type=0x%02x req=0x%02x wValue=0x%04x "
		    "wIndex=0x%04x len=%d, val=%d\n",
		    type, which, wValue, wIndex, len, val & 0xffff));
	err = usbd_do_request(sc->sc_udev, &req, data);
#ifdef UAUDIO_DEBUG
	if (err)
		DPRINTF(("uaudio_set: err=%d\n", err));
#endif
}

int
uaudio_signext(int type, int val)
{
	if (!MIX_UNSIGNED(type)) {
		if (MIX_SIZE(type) == 2)
			val = (int16_t)val;
		else
			val = (int8_t)val;
	}
	return (val);
}

int
uaudio_value2bsd(struct mixerctl *mc, int val)
{
	DPRINTFN(5, ("uaudio_value2bsd: type=%03x val=%d min=%d max=%d ",
		     mc->type, val, mc->minval, mc->maxval));
	if (mc->type == MIX_ON_OFF)
		val = (val != 0);
	else
		val = ((uaudio_signext(mc->type, val) - mc->minval) * 255
			+ mc->mul/2) / mc->mul;
	DPRINTFN(5, ("val'=%d\n", val));
	return (val);
}

int
uaudio_bsd2value(struct mixerctl *mc, int val)
{
	DPRINTFN(5,("uaudio_bsd2value: type=%03x val=%d min=%d max=%d ",
		    mc->type, val, mc->minval, mc->maxval));
	if (mc->type == MIX_ON_OFF)
		val = (val != 0);
	else
		val = (val + mc->delta/2) * mc->mul / 255 + mc->minval;
	DPRINTFN(5, ("val'=%d\n", val));
	return (val);
}

int
uaudio_ctl_get(struct uaudio_softc *sc, int which, struct mixerctl *mc,
	       int chan)
{
	int val;

	DPRINTFN(5,("uaudio_ctl_get: which=%d chan=%d\n", which, chan));
	val = uaudio_get(sc, which, UT_READ_CLASS_INTERFACE, mc->wValue[chan],
			 mc->wIndex, MIX_SIZE(mc->type));
	return (uaudio_value2bsd(mc, val));
}

void
uaudio_ctl_set(struct uaudio_softc *sc, int which, struct mixerctl *mc,
	       int chan, int val)
{
	val = uaudio_bsd2value(mc, val);
	uaudio_set(sc, which, UT_WRITE_CLASS_INTERFACE, mc->wValue[chan],
		   mc->wIndex, MIX_SIZE(mc->type), val);
}

int
uaudio_mixer_get_port(void *addr, mixer_ctrl_t *cp)
{
	struct uaudio_softc *sc = addr;
	struct mixerctl *mc;
	int i, n, vals[MIX_MAX_CHAN], val;

	DPRINTFN(2,("uaudio_mixer_get_port: index=%d\n", cp->dev));

	if (sc->sc_dying)
		return (EIO);

	n = cp->dev - UAC_NCLASSES;
	if (n < 0 || n >= sc->sc_nctls)
		return (ENXIO);
	mc = &sc->sc_ctls[n];

	if (mc->type == MIX_ON_OFF) {
		if (cp->type != AUDIO_MIXER_ENUM)
			return (EINVAL);
		cp->un.ord = uaudio_ctl_get(sc, GET_CUR, mc, 0);
	} else {
		if (cp->type != AUDIO_MIXER_VALUE)
			return (EINVAL);
		if (cp->un.value.num_channels != 1 &&
		    cp->un.value.num_channels != mc->nchan)
			return (EINVAL);
		for (i = 0; i < mc->nchan; i++)
			vals[i] = uaudio_ctl_get(sc, GET_CUR, mc, i);
		if (cp->un.value.num_channels == 1 && mc->nchan != 1) {
			for (val = 0, i = 0; i < mc->nchan; i++)
				val += vals[i];
			vals[0] = val / mc->nchan;
		}
		for (i = 0; i < cp->un.value.num_channels; i++)
			cp->un.value.level[i] = vals[i];
	}

	return (0);
}

int
uaudio_mixer_set_port(void *addr, mixer_ctrl_t *cp)
{
	struct uaudio_softc *sc = addr;
	struct mixerctl *mc;
	int i, n, vals[MIX_MAX_CHAN];

	DPRINTFN(2,("uaudio_mixer_set_port: index = %d\n", cp->dev));
	if (sc->sc_dying)
		return (EIO);

	n = cp->dev - UAC_NCLASSES;
	if (n < 0 || n >= sc->sc_nctls)
		return (ENXIO);
	mc = &sc->sc_ctls[n];

	if (mc->type == MIX_ON_OFF) {
		if (cp->type != AUDIO_MIXER_ENUM)
			return (EINVAL);
		uaudio_ctl_set(sc, SET_CUR, mc, 0, cp->un.ord);
	} else {
		if (cp->type != AUDIO_MIXER_VALUE)
			return (EINVAL);
		if (cp->un.value.num_channels == 1)
			for (i = 0; i < mc->nchan; i++)
				vals[i] = cp->un.value.level[0];
		else if (cp->un.value.num_channels == mc->nchan)
			for (i = 0; i < mc->nchan; i++)
				vals[i] = cp->un.value.level[i];
		else
			return (EINVAL);
		for (i = 0; i < mc->nchan; i++)
			uaudio_ctl_set(sc, SET_CUR, mc, i, vals[i]);
	}
	return (0);
}

int
uaudio_trigger_input(void *addr, void *start, void *end, int blksize,
		     void (*intr)(void *), void *arg,
		     struct audio_params *param)
{
	struct uaudio_softc *sc = addr;
	struct chan *ch = &sc->sc_recchan;
	usbd_status err;
	int i, s;

	if (sc->sc_dying)
		return (EIO);

	DPRINTFN(3,("uaudio_trigger_input: sc=%p start=%p end=%p "
		    "blksize=%d\n", sc, start, end, blksize));

	uaudio_chan_set_param(ch, start, end, blksize);
	DPRINTFN(3,("uaudio_trigger_input: sample_size=%d bytes/frame=%d "
		    "fraction=0.%03d\n", ch->sample_size, ch->bytes_per_frame,
		    ch->fraction));

	err = uaudio_chan_alloc_buffers(sc, ch);
	if (err)
		return (EIO);

	err = uaudio_chan_open(sc, ch);
	if (err) {
		uaudio_chan_free_buffers(sc, ch);
		return (EIO);
	}

	ch->intr = intr;
	ch->arg = arg;

	s = splusb();
	for (i = 0; i < UAUDIO_NCHANBUFS-1; i++) /* XXX -1 shouldn't be needed */
		uaudio_chan_rtransfer(ch);
	splx(s);

	return (0);
}

int
uaudio_trigger_output(void *addr, void *start, void *end, int blksize,
		      void (*intr)(void *), void *arg,
		      struct audio_params *param)
{
	struct uaudio_softc *sc = addr;
	struct chan *ch = &sc->sc_playchan;
	usbd_status err;
	int i, s;

	if (sc->sc_dying)
		return (EIO);

	DPRINTFN(3,("uaudio_trigger_output: sc=%p start=%p end=%p "
		    "blksize=%d\n", sc, start, end, blksize));

	uaudio_chan_set_param(ch, start, end, blksize);
	DPRINTFN(3,("uaudio_trigger_output: sample_size=%d bytes/frame=%d "
		    "fraction=0.%03d\n", ch->sample_size, ch->bytes_per_frame,
		    ch->fraction));

	err = uaudio_chan_alloc_buffers(sc, ch);
	if (err)
		return (EIO);

	err = uaudio_chan_open(sc, ch);
	if (err) {
		uaudio_chan_free_buffers(sc, ch);
		return (EIO);
	}

	ch->intr = intr;
	ch->arg = arg;

	s = splusb();
	for (i = 0; i < UAUDIO_NCHANBUFS-1; i++) /* XXX */
		uaudio_chan_ptransfer(ch);
	splx(s);

	return (0);
}

/* Set up a pipe for a channel. */
usbd_status
uaudio_chan_open(struct uaudio_softc *sc, struct chan *ch)
{
	struct as_info *as = &sc->sc_alts[ch->altidx];
	int endpt = as->edesc->bEndpointAddress;
	usbd_status err;

	DPRINTF(("uaudio_chan_open: endpt=0x%02x, speed=%d, alt=%d\n",
		 endpt, ch->sample_rate, as->alt));

	/* Set alternate interface corresponding to the mode. */
	err = usbd_set_interface(as->ifaceh, as->alt);
	if (err)
		return (err);

	/* Some devices do not support this request, so ignore errors. */
#ifdef UAUDIO_DEBUG
	err = uaudio_set_speed(sc, endpt, ch->sample_rate);
	if (err)
		DPRINTF(("uaudio_chan_open: set_speed failed err=%s\n",
			 usbd_errstr(err)));
#else
	(void)uaudio_set_speed(sc, endpt, ch->sample_rate);
#endif

	DPRINTF(("uaudio_chan_open: create pipe to 0x%02x\n", endpt));
	err = usbd_open_pipe(as->ifaceh, endpt, 0, &ch->pipe);
	return (err);
}

void
uaudio_chan_close(struct uaudio_softc *sc, struct chan *ch)
{
	struct as_info *as = &sc->sc_alts[ch->altidx];

	as->sc_busy = 0;
	if (sc->sc_nullalt >= 0) {
		DPRINTF(("uaudio_chan_close: set null alt=%d\n",
			 sc->sc_nullalt));
		usbd_set_interface(as->ifaceh, sc->sc_nullalt);
	}
	usbd_abort_pipe(ch->pipe);
	usbd_close_pipe(ch->pipe);
}

usbd_status
uaudio_chan_alloc_buffers(struct uaudio_softc *sc, struct chan *ch)
{
	usbd_xfer_handle xfer;
	void *buf;
	int i, size;

	size = (ch->bytes_per_frame + ch->sample_size) * UAUDIO_NFRAMES;
	for (i = 0; i < UAUDIO_NCHANBUFS; i++) {
		xfer = usbd_alloc_xfer(sc->sc_udev);
		if (xfer == 0)
			goto bad;
		ch->chanbufs[i].xfer = xfer;
		buf = usbd_alloc_buffer(xfer, size);
		if (buf == 0) {
			i++;
			goto bad;
		}
		ch->chanbufs[i].buffer = buf;
		ch->chanbufs[i].chan = ch;
	}

	return (USBD_NORMAL_COMPLETION);

bad:
	while (--i >= 0)
		/* implicit buffer free */
		usbd_free_xfer(ch->chanbufs[i].xfer);
	return (USBD_NOMEM);
}

void
uaudio_chan_free_buffers(struct uaudio_softc *sc, struct chan *ch)
{
	int i;

	for (i = 0; i < UAUDIO_NCHANBUFS; i++)
		usbd_free_xfer(ch->chanbufs[i].xfer);
}

/* Called at splusb() */
void
uaudio_chan_ptransfer(struct chan *ch)
{
	struct chanbuf *cb;
	int i, n, size, residue, total;

	if (ch->sc->sc_dying)
		return;

	/* Pick the next channel buffer. */
	cb = &ch->chanbufs[ch->curchanbuf];
	if (++ch->curchanbuf >= UAUDIO_NCHANBUFS)
		ch->curchanbuf = 0;

	/* Compute the size of each frame in the next transfer. */
	residue = ch->residue;
	total = 0;
	for (i = 0; i < UAUDIO_NFRAMES; i++) {
		size = ch->bytes_per_frame;
		residue += ch->fraction;
		if (residue >= USB_FRAMES_PER_SECOND) {
			if ((ch->sc->sc_altflags & UA_NOFRAC) == 0)
				size += ch->sample_size;
			residue -= USB_FRAMES_PER_SECOND;
		}
		cb->sizes[i] = size;
		total += size;
	}
	ch->residue = residue;
	cb->size = total;

	/*
	 * Transfer data from upper layer buffer to channel buffer, taking
	 * care of wrapping the upper layer buffer.
	 */
	n = min(total, ch->end - ch->cur);
	memcpy(cb->buffer, ch->cur, n);
	ch->cur += n;
	if (ch->cur >= ch->end)
		ch->cur = ch->start;
	if (total > n) {
		total -= n;
		memcpy(cb->buffer + n, ch->cur, total);
		ch->cur += total;
	}

#ifdef UAUDIO_DEBUG
	if (uaudiodebug > 8) {
		DPRINTF(("uaudio_chan_ptransfer: buffer=%p, residue=0.%03d\n",
			 cb->buffer, ch->residue));
		for (i = 0; i < UAUDIO_NFRAMES; i++) {
			DPRINTF(("   [%d] length %d\n", i, cb->sizes[i]));
		}
	}
#endif

	DPRINTFN(5,("uaudio_chan_transfer: ptransfer xfer=%p\n", cb->xfer));
	/* Fill the request */
	usbd_setup_isoc_xfer(cb->xfer, ch->pipe, cb, cb->sizes,
			     UAUDIO_NFRAMES, USBD_NO_COPY,
			     uaudio_chan_pintr);

	(void)usbd_transfer(cb->xfer);
}

void
uaudio_chan_pintr(usbd_xfer_handle xfer, usbd_private_handle priv,
		  usbd_status status)
{
	struct chanbuf *cb = priv;
	struct chan *ch = cb->chan;
	u_int32_t count;
	int s;

	/* Return if we are aborting. */
	if (status == USBD_CANCELLED)
		return;

	usbd_get_xfer_status(xfer, NULL, NULL, &count, NULL);
	DPRINTFN(5,("uaudio_chan_pintr: count=%d, transferred=%d\n",
		    count, ch->transferred));
#ifdef DIAGNOSTIC
	if (count != cb->size) {
		printf("uaudio_chan_pintr: count(%d) != size(%d)\n",
		       count, cb->size);
	}
#endif

	ch->transferred += cb->size;
	s = splaudio();
	/* Call back to upper layer */
	while (ch->transferred >= ch->blksize) {
		ch->transferred -= ch->blksize;
		DPRINTFN(5,("uaudio_chan_pintr: call %p(%p)\n",
			    ch->intr, ch->arg));
		ch->intr(ch->arg);
	}
	splx(s);

	/* start next transfer */
	uaudio_chan_ptransfer(ch);
}

/* Called at splusb() */
void
uaudio_chan_rtransfer(struct chan *ch)
{
	struct chanbuf *cb;
	int i, size, residue, total;

	if (ch->sc->sc_dying)
		return;

	/* Pick the next channel buffer. */
	cb = &ch->chanbufs[ch->curchanbuf];
	if (++ch->curchanbuf >= UAUDIO_NCHANBUFS)
		ch->curchanbuf = 0;

	/* Compute the size of each frame in the next transfer. */
	residue = ch->residue;
	total = 0;
	for (i = 0; i < UAUDIO_NFRAMES; i++) {
		size = ch->bytes_per_frame;
		cb->sizes[i] = size;
		cb->offsets[i] = total;
		total += size;
	}
	ch->residue = residue;
	cb->size = total;

#ifdef UAUDIO_DEBUG
	if (uaudiodebug > 8) {
		DPRINTF(("uaudio_chan_rtransfer: buffer=%p, residue=0.%03d\n",
			 cb->buffer, ch->residue));
		for (i = 0; i < UAUDIO_NFRAMES; i++) {
			DPRINTF(("   [%d] length %d\n", i, cb->sizes[i]));
		}
	}
#endif

	DPRINTFN(5,("uaudio_chan_rtransfer: transfer xfer=%p\n", cb->xfer));
	/* Fill the request */
	usbd_setup_isoc_xfer(cb->xfer, ch->pipe, cb, cb->sizes,
			     UAUDIO_NFRAMES, USBD_NO_COPY,
			     uaudio_chan_rintr);

	(void)usbd_transfer(cb->xfer);
}

void
uaudio_chan_rintr(usbd_xfer_handle xfer, usbd_private_handle priv,
		  usbd_status status)
{
	struct chanbuf *cb = priv;
	struct chan *ch = cb->chan;
	u_int32_t count;
	int s, i, n, frsize;

	/* Return if we are aborting. */
	if (status == USBD_CANCELLED)
		return;

	usbd_get_xfer_status(xfer, NULL, NULL, &count, NULL);
	DPRINTFN(5,("uaudio_chan_rintr: count=%d, transferred=%d\n",
		    count, ch->transferred));

	/* count < cb->size is normal for asynchronous source */
#ifdef DIAGNOSTIC
	if (count > cb->size) {
		printf("uaudio_chan_rintr: count(%d) > size(%d)\n",
		       count, cb->size);
	}
#endif

	/*
	 * Transfer data from channel buffer to upper layer buffer, taking
	 * care of wrapping the upper layer buffer.
	 */
	for(i = 0; i < UAUDIO_NFRAMES; i++) {
		frsize = cb->sizes[i];
		n = min(frsize, ch->end - ch->cur);
		memcpy(ch->cur, cb->buffer + cb->offsets[i], n);
		ch->cur += n;
		if (ch->cur >= ch->end)
			ch->cur = ch->start;
		if (frsize > n) {
			memcpy(ch->cur, cb->buffer + cb->offsets[i] + n,
			    frsize - n);
			ch->cur += frsize - n;
		}
	}

	/* Call back to upper layer */
	ch->transferred += count;
	s = splaudio();
	while (ch->transferred >= ch->blksize) {
		ch->transferred -= ch->blksize;
		DPRINTFN(5,("uaudio_chan_rintr: call %p(%p)\n",
			    ch->intr, ch->arg));
		ch->intr(ch->arg);
	}
	splx(s);

	/* start next transfer */
	uaudio_chan_rtransfer(ch);
}

void
uaudio_chan_init(struct chan *ch, int altidx, const struct audio_params *param,
    int maxpktsize)
{
	int samples_per_frame, sample_size;

	ch->altidx = altidx;
	sample_size = param->precision * param->factor * param->hw_channels / 8;
	samples_per_frame = param->hw_sample_rate / USB_FRAMES_PER_SECOND;
	ch->sample_size = sample_size;
	ch->sample_rate = param->hw_sample_rate;
	if (maxpktsize == 0) {
		ch->fraction = param->hw_sample_rate % USB_FRAMES_PER_SECOND;
		ch->bytes_per_frame = samples_per_frame * sample_size;
	} else {
		ch->fraction = 0;
		ch->bytes_per_frame = maxpktsize;
	}
	ch->residue = 0;
}

void
uaudio_chan_set_param(struct chan *ch, u_char *start, u_char *end, int blksize)
{
	ch->start = start;
	ch->end = end;
	ch->cur = start;
	ch->blksize = blksize;
	ch->transferred = 0;

	ch->curchanbuf = 0;
}

void
uaudio_get_minmax_rates(int nalts, const struct as_info *alts,
			const struct audio_params *p, int mode,
			u_long *min, u_long *max)
{
	const struct usb_audio_streaming_type1_descriptor *a1d;
	int i, j;

	*min = ULONG_MAX;
	*max = 0;
	for (i = 0; i < nalts; i++) {
		a1d = alts[i].asf1desc;
		if (alts[i].sc_busy)
			continue;
		if (p->hw_channels != a1d->bNrChannels)
			continue;
		if (p->hw_precision != a1d->bBitResolution)
			continue;
		if (p->hw_encoding != alts[i].encoding)
			continue;
		if (mode != UE_GET_DIR(alts[i].edesc->bEndpointAddress))
			continue;
		if (a1d->bSamFreqType == UA_SAMP_CONTNUOUS) {
			DPRINTFN(2,("uaudio_get_minmax_rates: cont %d-%d\n",
				    UA_SAMP_LO(a1d), UA_SAMP_HI(a1d)));
			if (UA_SAMP_LO(a1d) < *min)
				*min = UA_SAMP_LO(a1d);
			if (UA_SAMP_HI(a1d) > *max)
				*max = UA_SAMP_HI(a1d);
		} else {
			for (j = 0; j < a1d->bSamFreqType; j++) {
				DPRINTFN(2,("uaudio_get_minmax_rates: disc #%d: %d\n",
					    j, UA_GETSAMP(a1d, j)));
				if (UA_GETSAMP(a1d, j) < *min)
					*min = UA_GETSAMP(a1d, j);
				if (UA_GETSAMP(a1d, j) > *max)
					*max = UA_GETSAMP(a1d, j);
			}
		}
	}
}

int
uaudio_match_alt_sub(int nalts, const struct as_info *alts,
		     const struct audio_params *p, int mode, u_long rate)
{
	const struct usb_audio_streaming_type1_descriptor *a1d;
	int i, j;

	DPRINTF(("uaudio_match_alt_sub: search for %luHz %dch\n",
		 rate, p->hw_channels));
	for (i = 0; i < nalts; i++) {
		a1d = alts[i].asf1desc;
		if (alts[i].sc_busy)
			continue;
		if (p->hw_channels != a1d->bNrChannels)
			continue;
		if (p->hw_precision != a1d->bBitResolution)
			continue;
		if (p->hw_encoding != alts[i].encoding)
			continue;
		if (mode != UE_GET_DIR(alts[i].edesc->bEndpointAddress))
			continue;
		if (a1d->bSamFreqType == UA_SAMP_CONTNUOUS) {
			DPRINTFN(2,("uaudio_match_alt_sub: cont %d-%d\n",
				    UA_SAMP_LO(a1d), UA_SAMP_HI(a1d)));
			if (UA_SAMP_LO(a1d) <= rate && rate <= UA_SAMP_HI(a1d))
				return i;
		} else {
			for (j = 0; j < a1d->bSamFreqType; j++) {
				DPRINTFN(2,("uaudio_match_alt_sub: disc #%d: %d\n",
					    j, UA_GETSAMP(a1d, j)));
				/* XXX allow for some slack */
				if (UA_GETSAMP(a1d, j) == rate)
					return i;
			}
		}
	}
	return -1;
}

int
uaudio_match_alt_chan(int nalts, const struct as_info *alts,
		      struct audio_params *p, int mode)
{
	int i, n;
	u_long min, max;
	u_long rate;

	/* Exact match */
	DPRINTF(("uaudio_match_alt_chan: examine %ldHz %dch %dbit.\n",
		 p->sample_rate, p->hw_channels, p->hw_precision));
	i = uaudio_match_alt_sub(nalts, alts, p, mode, p->sample_rate);
	if (i >= 0)
		return i;

	uaudio_get_minmax_rates(nalts, alts, p, mode, &min, &max);
	DPRINTF(("uaudio_match_alt_chan: min=%lu max=%lu\n", min, max));
	if (max <= 0)
		return -1;
	/* Search for biggers */
	n = 2;
	while ((rate = p->sample_rate * n++) <= max) {
		i = uaudio_match_alt_sub(nalts, alts, p, mode, rate);
		if (i >= 0) {
			p->hw_sample_rate = rate;
			return i;
		}
	}
	if (p->sample_rate >= min) {
		i = uaudio_match_alt_sub(nalts, alts, p, mode, max);
		if (i >= 0) {
			p->hw_sample_rate = max;
			return i;
		}
	} else {
		i = uaudio_match_alt_sub(nalts, alts, p, mode, min);
		if (i >= 0) {
			p->hw_sample_rate = min;
			return i;
		}
	}
	return -1;
}

int
uaudio_match_alt(int nalts, const struct as_info *alts,
		 struct audio_params *p, int mode)
{
	int i, n;

	mode = mode == AUMODE_PLAY ? UE_DIR_OUT : UE_DIR_IN;
	i = uaudio_match_alt_chan(nalts, alts, p, mode);
	if (i >= 0)
		return i;

	for (n = p->channels + 1; n <= AUDIO_MAX_CHANNELS; n++) {
		p->hw_channels = n;
		i = uaudio_match_alt_chan(nalts, alts, p, mode);
		if (i >= 0)
			return i;
	}

	if (p->channels != 2)
		return -1;
	p->hw_channels = 1;
	return uaudio_match_alt_chan(nalts, alts, p, mode);
}

int
uaudio_set_params(void *addr, int setmode, int usemode,
		  struct audio_params *play, struct audio_params *rec)
{
	struct uaudio_softc *sc = addr;
	int flags = sc->sc_altflags;
	int factor;
	int enc, i;
	int paltidx=-1, raltidx=-1;
	void (*swcode)(void *, u_char *buf, int cnt);
	struct audio_params *p;
	int mode;

	if (sc->sc_dying)
		return (EIO);

	if (((usemode & AUMODE_PLAY) && sc->sc_playchan.pipe != NULL) ||
	    ((usemode & AUMODE_RECORD) && sc->sc_recchan.pipe != NULL))
		return (EBUSY);

	if ((usemode & AUMODE_PLAY) && sc->sc_playchan.altidx != -1)
		sc->sc_alts[sc->sc_playchan.altidx].sc_busy = 0;
	if ((usemode & AUMODE_RECORD) && sc->sc_recchan.altidx != -1)
		sc->sc_alts[sc->sc_recchan.altidx].sc_busy = 0;

	/* Some uaudio devices are unidirectional.  Don't try to find a
	   matching mode for the unsupported direction. */
	setmode &= sc->sc_mode;

	for (mode = AUMODE_RECORD; mode != -1;
	     mode = mode == AUMODE_RECORD ? AUMODE_PLAY : -1) {
		if ((setmode & mode) == 0)
			continue;

		p = (mode == AUMODE_PLAY) ? play : rec;

		factor = 1;
		swcode = 0;
		enc = p->encoding;
		switch (enc) {
		case AUDIO_ENCODING_SLINEAR_BE:
			/* FALLTHROUGH */
		case AUDIO_ENCODING_SLINEAR_LE:
			if (enc == AUDIO_ENCODING_SLINEAR_BE
			    && p->precision == 16 && (flags & HAS_16)) {
				swcode = swap_bytes;
				enc = AUDIO_ENCODING_SLINEAR_LE;
			} else if (p->precision == 8) {
				if (flags & HAS_8) {
					/* No conversion */
				} else if (flags & HAS_8U) {
					swcode = change_sign8;
					enc = AUDIO_ENCODING_ULINEAR_LE;
				} else if (flags & HAS_16) {
					factor = 2;
					p->hw_precision = 16;
					if (mode == AUMODE_PLAY)
						swcode = linear8_to_linear16_le;
					else
						swcode = linear16_to_linear8_le;
				}
			}
			break;
		case AUDIO_ENCODING_ULINEAR_BE:
			/* FALLTHROUGH */
		case AUDIO_ENCODING_ULINEAR_LE:
			if (p->precision == 16) {
				if (enc == AUDIO_ENCODING_ULINEAR_LE)
					swcode = change_sign16_le;
				else if (mode == AUMODE_PLAY)
					swcode = swap_bytes_change_sign16_le;
				else
					swcode = change_sign16_swap_bytes_le;
				enc = AUDIO_ENCODING_SLINEAR_LE;
			} else if (p->precision == 8) {
				if (flags & HAS_8U) {
					/* No conversion */
				} else if (flags & HAS_8) {
					swcode = change_sign8;
					enc = AUDIO_ENCODING_SLINEAR_LE;
				} else if (flags & HAS_16) {
					factor = 2;
					p->hw_precision = 16;
					enc = AUDIO_ENCODING_SLINEAR_LE;
					if (mode == AUMODE_PLAY)
						swcode = ulinear8_to_slinear16_le;
					else
						swcode = slinear16_to_ulinear8_le;
				}
			}
			break;
		case AUDIO_ENCODING_ULAW:
			if (flags & HAS_MULAW)
				break;
			if (flags & HAS_16) {
				if (mode == AUMODE_PLAY)
					swcode = mulaw_to_slinear16_le;
				else
					swcode = slinear16_to_mulaw_le;
				factor = 2;
				enc = AUDIO_ENCODING_SLINEAR_LE;
				p->hw_precision = 16;
			} else if (flags & HAS_8U) {
				if (mode == AUMODE_PLAY)
					swcode = mulaw_to_ulinear8;
				else
					swcode = ulinear8_to_mulaw;
				enc = AUDIO_ENCODING_ULINEAR_LE;
			} else if (flags & HAS_8) {
				if (mode == AUMODE_PLAY)
					swcode = mulaw_to_slinear8;
				else
					swcode = slinear8_to_mulaw;
				enc = AUDIO_ENCODING_SLINEAR_LE;
			} else
				return (EINVAL);
			break;
		case AUDIO_ENCODING_ALAW:
			if (flags & HAS_ALAW)
				break;
			if (mode == AUMODE_PLAY && (flags & HAS_16)) {
				swcode = alaw_to_slinear16_le;
				factor = 2;
				enc = AUDIO_ENCODING_SLINEAR_LE;
				p->hw_precision = 16;
			} else if (flags & HAS_8U) {
				if (mode == AUMODE_PLAY)
					swcode = alaw_to_ulinear8;
				else
					swcode = ulinear8_to_alaw;
				enc = AUDIO_ENCODING_ULINEAR_LE;
			} else if (flags & HAS_8) {
				if (mode == AUMODE_PLAY)
					swcode = alaw_to_slinear8;
				else
					swcode = slinear8_to_alaw;
				enc = AUDIO_ENCODING_SLINEAR_LE;
			} else
				return (EINVAL);
			break;
		default:
			return (EINVAL);
		}
		/* XXX do some other conversions... */

		DPRINTF(("uaudio_set_params: chan=%d prec=%d enc=%d rate=%ld\n",
			 p->channels, p->hw_precision, enc, p->sample_rate));

		p->hw_encoding = enc;
		i = uaudio_match_alt(sc->sc_nalts, sc->sc_alts, p, mode);
		if (i < 0)
			return (EINVAL);

		p->sw_code = swcode;
		p->factor  = factor;

		if (mode == AUMODE_PLAY)
			paltidx = i;
		else
			raltidx = i;
	}

	if ((setmode & AUMODE_PLAY)) {
		/* XXX abort transfer if currently happening? */
		uaudio_chan_init(&sc->sc_playchan, paltidx, play, 0);
	}
	if ((setmode & AUMODE_RECORD)) {
		/* XXX abort transfer if currently happening? */
		uaudio_chan_init(&sc->sc_recchan, raltidx, rec,
		    UGETW(sc->sc_alts[raltidx].edesc->wMaxPacketSize));
	}

	if ((usemode & AUMODE_PLAY) && sc->sc_playchan.altidx != -1)
		sc->sc_alts[sc->sc_playchan.altidx].sc_busy = 1;
	if ((usemode & AUMODE_RECORD) && sc->sc_recchan.altidx != -1)
		sc->sc_alts[sc->sc_recchan.altidx].sc_busy = 1;

	DPRINTF(("uaudio_set_params: use altidx=p%d/r%d, altno=p%d/r%d\n",
		 sc->sc_playchan.altidx, sc->sc_recchan.altidx,
		 (sc->sc_playchan.altidx >= 0)
		   ?sc->sc_alts[sc->sc_playchan.altidx].idesc->bAlternateSetting
		   : -1,
		 (sc->sc_recchan.altidx >= 0)
		   ? sc->sc_alts[sc->sc_recchan.altidx].idesc->bAlternateSetting
		   : -1));

	return (0);
}

usbd_status
uaudio_set_speed(struct uaudio_softc *sc, int endpt, u_int speed)
{
	usb_device_request_t req;
	u_int8_t data[3];

	DPRINTFN(5,("uaudio_set_speed: endpt=%d speed=%u\n", endpt, speed));
	req.bmRequestType = UT_WRITE_CLASS_ENDPOINT;
	req.bRequest = SET_CUR;
	USETW2(req.wValue, SAMPLING_FREQ_CONTROL, 0);
	USETW(req.wIndex, endpt);
	USETW(req.wLength, 3);
	data[0] = speed;
	data[1] = speed >> 8;
	data[2] = speed >> 16;

	return (usbd_do_request(sc->sc_udev, &req, data));
}