Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-artful-kernel.git] / sound / usb / quirks.c

/*
 *   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
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>

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

#include "usbaudio.h"
#include "card.h"
#include "mixer.h"
#include "mixer_quirks.h"
#include "midi.h"
#include "quirks.h"
#include "helper.h"
#include "endpoint.h"
#include "pcm.h"
#include "clock.h"
#include "stream.h"

/*
 * handle the quirks for the contained interfaces
 */
static int create_composite_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver,
                                  const struct snd_usb_audio_quirk *quirk_comp)
{
        int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
        const struct snd_usb_audio_quirk *quirk;
        int err;

        for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
                iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
                if (!iface)
                        continue;
                if (quirk->ifnum != probed_ifnum &&
                    usb_interface_claimed(iface))
                        continue;
                err = snd_usb_create_quirk(chip, iface, driver, quirk);
                if (err < 0)
                        return err;
        }

        for (quirk = quirk_comp->data; quirk->ifnum >= 0; ++quirk) {
                iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
                if (!iface)
                        continue;
                if (quirk->ifnum != probed_ifnum &&
                    !usb_interface_claimed(iface))
                        usb_driver_claim_interface(driver, iface, (void *)-1L);
        }

        return 0;
}

static int ignore_interface_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver,
                                  const struct snd_usb_audio_quirk *quirk)
{
        return 0;
}


/*
 * Allow alignment on audio sub-slot (channel samples) rather than
 * on audio slots (audio frames)
 */
static int create_align_transfer_quirk(struct snd_usb_audio *chip,
                                       struct usb_interface *iface,
                                       struct usb_driver *driver,
                                       const struct snd_usb_audio_quirk *quirk)
{
        chip->txfr_quirk = 1;
        return 1;       /* Continue with creating streams and mixer */
}

static int create_any_midi_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *intf,
                                 struct usb_driver *driver,
                                 const struct snd_usb_audio_quirk *quirk)
{
        return snd_usbmidi_create(chip->card, intf, &chip->midi_list, quirk);
}

/*
 * create a stream for an interface with proper descriptors
 */
static int create_standard_audio_quirk(struct snd_usb_audio *chip,
                                       struct usb_interface *iface,
                                       struct usb_driver *driver,
                                       const struct snd_usb_audio_quirk *quirk)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        int err;

        if (chip->usb_id == USB_ID(0x1686, 0x00dd)) /* Zoom R16/24 */
                chip->tx_length_quirk = 1;

        alts = &iface->altsetting[0];
        altsd = get_iface_desc(alts);
        err = snd_usb_parse_audio_interface(chip, altsd->bInterfaceNumber);
        if (err < 0) {
                usb_audio_err(chip, "cannot setup if %d: error %d\n",
                           altsd->bInterfaceNumber, err);
                return err;
        }
        /* reset the current interface */
        usb_set_interface(chip->dev, altsd->bInterfaceNumber, 0);
        return 0;
}

/*
 * create a stream for an endpoint/altsetting without proper descriptors
 */
static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
                                     struct usb_interface *iface,
                                     struct usb_driver *driver,
                                     const struct snd_usb_audio_quirk *quirk)
{
        struct audioformat *fp;
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        int stream, err;
        unsigned *rate_table = NULL;

        fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
        if (!fp) {
                usb_audio_err(chip, "cannot memdup\n");
                return -ENOMEM;
        }
        INIT_LIST_HEAD(&fp->list);
        if (fp->nr_rates > MAX_NR_RATES) {
                kfree(fp);
                return -EINVAL;
        }
        if (fp->nr_rates > 0) {
                rate_table = kmemdup(fp->rate_table,
                                     sizeof(int) * fp->nr_rates, GFP_KERNEL);
                if (!rate_table) {
                        kfree(fp);
                        return -ENOMEM;
                }
                fp->rate_table = rate_table;
        }

        stream = (fp->endpoint & USB_DIR_IN)
                ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
        err = snd_usb_add_audio_stream(chip, stream, fp);
        if (err < 0)
                goto error;
        if (fp->iface != get_iface_desc(&iface->altsetting[0])->bInterfaceNumber ||
            fp->altset_idx >= iface->num_altsetting) {
                err = -EINVAL;
                goto error;
        }
        alts = &iface->altsetting[fp->altset_idx];
        altsd = get_iface_desc(alts);
        if (altsd->bNumEndpoints < 1) {
                err = -EINVAL;
                goto error;
        }

        fp->protocol = altsd->bInterfaceProtocol;

        if (fp->datainterval == 0)
                fp->datainterval = snd_usb_parse_datainterval(chip, alts);
        if (fp->maxpacksize == 0)
                fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
        usb_set_interface(chip->dev, fp->iface, 0);
        snd_usb_init_pitch(chip, fp->iface, alts, fp);
        snd_usb_init_sample_rate(chip, fp->iface, alts, fp, fp->rate_max);
        return 0;

 error:
        list_del(&fp->list); /* unlink for avoiding double-free */
        kfree(fp);
        kfree(rate_table);
        return err;
}

static int create_auto_pcm_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *iface,
                                 struct usb_driver *driver)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct usb_endpoint_descriptor *epd;
        struct uac1_as_header_descriptor *ashd;
        struct uac_format_type_i_discrete_descriptor *fmtd;

        /*
         * Most Roland/Yamaha audio streaming interfaces have more or less
         * standard descriptors, but older devices might lack descriptors, and
         * future ones might change, so ensure that we fail silently if the
         * interface doesn't look exactly right.
         */

        /* must have a non-zero altsetting for streaming */
        if (iface->num_altsetting < 2)
                return -ENODEV;
        alts = &iface->altsetting[1];
        altsd = get_iface_desc(alts);

        /* must have an isochronous endpoint for streaming */
        if (altsd->bNumEndpoints < 1)
                return -ENODEV;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_xfer_isoc(epd))
                return -ENODEV;

        /* must have format descriptors */
        ashd = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
                                       UAC_AS_GENERAL);
        fmtd = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL,
                                       UAC_FORMAT_TYPE);
        if (!ashd || ashd->bLength < 7 ||
            !fmtd || fmtd->bLength < 8)
                return -ENODEV;

        return create_standard_audio_quirk(chip, iface, driver, NULL);
}

static int create_yamaha_midi_quirk(struct snd_usb_audio *chip,
                                    struct usb_interface *iface,
                                    struct usb_driver *driver,
                                    struct usb_host_interface *alts)
{
        static const struct snd_usb_audio_quirk yamaha_midi_quirk = {
                .type = QUIRK_MIDI_YAMAHA
        };
        struct usb_midi_in_jack_descriptor *injd;
        struct usb_midi_out_jack_descriptor *outjd;

        /* must have some valid jack descriptors */
        injd = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                       NULL, USB_MS_MIDI_IN_JACK);
        outjd = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                        NULL, USB_MS_MIDI_OUT_JACK);
        if (!injd && !outjd)
                return -ENODEV;
        if (injd && (injd->bLength < 5 ||
                     (injd->bJackType != USB_MS_EMBEDDED &&
                      injd->bJackType != USB_MS_EXTERNAL)))
                return -ENODEV;
        if (outjd && (outjd->bLength < 6 ||
                      (outjd->bJackType != USB_MS_EMBEDDED &&
                       outjd->bJackType != USB_MS_EXTERNAL)))
                return -ENODEV;
        return create_any_midi_quirk(chip, iface, driver, &yamaha_midi_quirk);
}

static int create_roland_midi_quirk(struct snd_usb_audio *chip,
                                    struct usb_interface *iface,
                                    struct usb_driver *driver,
                                    struct usb_host_interface *alts)
{
        static const struct snd_usb_audio_quirk roland_midi_quirk = {
                .type = QUIRK_MIDI_ROLAND
        };
        u8 *roland_desc = NULL;

        /* might have a vendor-specific descriptor <06 24 F1 02 ...> */
        for (;;) {
                roland_desc = snd_usb_find_csint_desc(alts->extra,
                                                      alts->extralen,
                                                      roland_desc, 0xf1);
                if (!roland_desc)
                        return -ENODEV;
                if (roland_desc[0] < 6 || roland_desc[3] != 2)
                        continue;
                return create_any_midi_quirk(chip, iface, driver,
                                             &roland_midi_quirk);
        }
}

static int create_std_midi_quirk(struct snd_usb_audio *chip,
                                 struct usb_interface *iface,
                                 struct usb_driver *driver,
                                 struct usb_host_interface *alts)
{
        struct usb_ms_header_descriptor *mshd;
        struct usb_ms_endpoint_descriptor *msepd;

        /* must have the MIDIStreaming interface header descriptor*/
        mshd = (struct usb_ms_header_descriptor *)alts->extra;
        if (alts->extralen < 7 ||
            mshd->bLength < 7 ||
            mshd->bDescriptorType != USB_DT_CS_INTERFACE ||
            mshd->bDescriptorSubtype != USB_MS_HEADER)
                return -ENODEV;
        /* must have the MIDIStreaming endpoint descriptor*/
        msepd = (struct usb_ms_endpoint_descriptor *)alts->endpoint[0].extra;
        if (alts->endpoint[0].extralen < 4 ||
            msepd->bLength < 4 ||
            msepd->bDescriptorType != USB_DT_CS_ENDPOINT ||
            msepd->bDescriptorSubtype != UAC_MS_GENERAL ||
            msepd->bNumEmbMIDIJack < 1 ||
            msepd->bNumEmbMIDIJack > 16)
                return -ENODEV;

        return create_any_midi_quirk(chip, iface, driver, NULL);
}

static int create_auto_midi_quirk(struct snd_usb_audio *chip,
                                  struct usb_interface *iface,
                                  struct usb_driver *driver)
{
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct usb_endpoint_descriptor *epd;
        int err;

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

        /* must have at least one bulk/interrupt endpoint for streaming */
        if (altsd->bNumEndpoints < 1)
                return -ENODEV;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_xfer_bulk(epd) &&
            !usb_endpoint_xfer_int(epd))
                return -ENODEV;

        switch (USB_ID_VENDOR(chip->usb_id)) {
        case 0x0499: /* Yamaha */
                err = create_yamaha_midi_quirk(chip, iface, driver, alts);
                if (err != -ENODEV)
                        return err;
                break;
        case 0x0582: /* Roland */
                err = create_roland_midi_quirk(chip, iface, driver, alts);
                if (err != -ENODEV)
                        return err;
                break;
        }

        return create_std_midi_quirk(chip, iface, driver, alts);
}

static int create_autodetect_quirk(struct snd_usb_audio *chip,
                                   struct usb_interface *iface,
                                   struct usb_driver *driver)
{
        int err;

        err = create_auto_pcm_quirk(chip, iface, driver);
        if (err == -ENODEV)
                err = create_auto_midi_quirk(chip, iface, driver);
        return err;
}

static int create_autodetect_quirks(struct snd_usb_audio *chip,
                                    struct usb_interface *iface,
                                    struct usb_driver *driver,
                                    const struct snd_usb_audio_quirk *quirk)
{
        int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
        int ifcount, ifnum, err;

        err = create_autodetect_quirk(chip, iface, driver);
        if (err < 0)
                return err;

        /*
         * ALSA PCM playback/capture devices cannot be registered in two steps,
         * so we have to claim the other corresponding interface here.
         */
        ifcount = chip->dev->actconfig->desc.bNumInterfaces;
        for (ifnum = 0; ifnum < ifcount; ifnum++) {
                if (ifnum == probed_ifnum || quirk->ifnum >= 0)
                        continue;
                iface = usb_ifnum_to_if(chip->dev, ifnum);
                if (!iface ||
                    usb_interface_claimed(iface) ||
                    get_iface_desc(iface->altsetting)->bInterfaceClass !=
                                                        USB_CLASS_VENDOR_SPEC)
                        continue;

                err = create_autodetect_quirk(chip, iface, driver);
                if (err >= 0)
                        usb_driver_claim_interface(driver, iface, (void *)-1L);
        }

        return 0;
}

/*
 * Create a stream for an Edirol UA-700/UA-25/UA-4FX interface.  
 * The only way to detect the sample rate is by looking at wMaxPacketSize.
 */
static int create_uaxx_quirk(struct snd_usb_audio *chip,
                             struct usb_interface *iface,
                             struct usb_driver *driver,
                             const struct snd_usb_audio_quirk *quirk)
{
        static const struct audioformat ua_format = {
                .formats = SNDRV_PCM_FMTBIT_S24_3LE,
                .channels = 2,
                .fmt_type = UAC_FORMAT_TYPE_I,
                .altsetting = 1,
                .altset_idx = 1,
                .rates = SNDRV_PCM_RATE_CONTINUOUS,
        };
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        struct audioformat *fp;
        int stream, err;

        /* both PCM and MIDI interfaces have 2 or more altsettings */
        if (iface->num_altsetting < 2)
                return -ENXIO;
        alts = &iface->altsetting[1];
        altsd = get_iface_desc(alts);

        if (altsd->bNumEndpoints == 2) {
                static const struct snd_usb_midi_endpoint_info ua700_ep = {
                        .out_cables = 0x0003,
                        .in_cables  = 0x0003
                };
                static const struct snd_usb_audio_quirk ua700_quirk = {
                        .type = QUIRK_MIDI_FIXED_ENDPOINT,
                        .data = &ua700_ep
                };
                static const struct snd_usb_midi_endpoint_info uaxx_ep = {
                        .out_cables = 0x0001,
                        .in_cables  = 0x0001
                };
                static const struct snd_usb_audio_quirk uaxx_quirk = {
                        .type = QUIRK_MIDI_FIXED_ENDPOINT,
                        .data = &uaxx_ep
                };
                const struct snd_usb_audio_quirk *quirk =
                        chip->usb_id == USB_ID(0x0582, 0x002b)
                        ? &ua700_quirk : &uaxx_quirk;
                return __snd_usbmidi_create(chip->card, iface,
                                          &chip->midi_list, quirk,
                                          chip->usb_id);
        }

        if (altsd->bNumEndpoints != 1)
                return -ENXIO;

        fp = kmemdup(&ua_format, sizeof(*fp), GFP_KERNEL);
        if (!fp)
                return -ENOMEM;

        fp->iface = altsd->bInterfaceNumber;
        fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
        fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
        fp->datainterval = 0;
        fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
        INIT_LIST_HEAD(&fp->list);

        switch (fp->maxpacksize) {
        case 0x120:
                fp->rate_max = fp->rate_min = 44100;
                break;
        case 0x138:
        case 0x140:
                fp->rate_max = fp->rate_min = 48000;
                break;
        case 0x258:
        case 0x260:
                fp->rate_max = fp->rate_min = 96000;
                break;
        default:
                usb_audio_err(chip, "unknown sample rate\n");
                kfree(fp);
                return -ENXIO;
        }

        stream = (fp->endpoint & USB_DIR_IN)
                ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
        err = snd_usb_add_audio_stream(chip, stream, fp);
        if (err < 0) {
                list_del(&fp->list); /* unlink for avoiding double-free */
                kfree(fp);
                return err;
        }
        usb_set_interface(chip->dev, fp->iface, 0);
        return 0;
}

/*
 * Create a standard mixer for the specified interface.
 */
static int create_standard_mixer_quirk(struct snd_usb_audio *chip,
                                       struct usb_interface *iface,
                                       struct usb_driver *driver,
                                       const struct snd_usb_audio_quirk *quirk)
{
        if (quirk->ifnum < 0)
                return 0;

        return snd_usb_create_mixer(chip, quirk->ifnum, 0);
}

/*
 * audio-interface quirks
 *
 * returns zero if no standard audio/MIDI parsing is needed.
 * returns a positive value if standard audio/midi interfaces are parsed
 * after this.
 * returns a negative value at error.
 */
int snd_usb_create_quirk(struct snd_usb_audio *chip,
                         struct usb_interface *iface,
                         struct usb_driver *driver,
                         const struct snd_usb_audio_quirk *quirk)
{
        typedef int (*quirk_func_t)(struct snd_usb_audio *,
                                    struct usb_interface *,
                                    struct usb_driver *,
                                    const struct snd_usb_audio_quirk *);
        static const quirk_func_t quirk_funcs[] = {
                [QUIRK_IGNORE_INTERFACE] = ignore_interface_quirk,
                [QUIRK_COMPOSITE] = create_composite_quirk,
                [QUIRK_AUTODETECT] = create_autodetect_quirks,
                [QUIRK_MIDI_STANDARD_INTERFACE] = create_any_midi_quirk,
                [QUIRK_MIDI_FIXED_ENDPOINT] = create_any_midi_quirk,
                [QUIRK_MIDI_YAMAHA] = create_any_midi_quirk,
                [QUIRK_MIDI_ROLAND] = create_any_midi_quirk,
                [QUIRK_MIDI_MIDIMAN] = create_any_midi_quirk,
                [QUIRK_MIDI_NOVATION] = create_any_midi_quirk,
                [QUIRK_MIDI_RAW_BYTES] = create_any_midi_quirk,
                [QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,
                [QUIRK_MIDI_CME] = create_any_midi_quirk,
                [QUIRK_MIDI_AKAI] = create_any_midi_quirk,
                [QUIRK_MIDI_FTDI] = create_any_midi_quirk,
                [QUIRK_MIDI_CH345] = create_any_midi_quirk,
                [QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk,
                [QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk,
                [QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,
                [QUIRK_AUDIO_ALIGN_TRANSFER] = create_align_transfer_quirk,
                [QUIRK_AUDIO_STANDARD_MIXER] = create_standard_mixer_quirk,
        };

        if (quirk->type < QUIRK_TYPE_COUNT) {
                return quirk_funcs[quirk->type](chip, iface, driver, quirk);
        } else {
                usb_audio_err(chip, "invalid quirk type %d\n", quirk->type);
                return -ENXIO;
        }
}

/*
 * boot quirks
 */

#define EXTIGY_FIRMWARE_SIZE_OLD 794
#define EXTIGY_FIRMWARE_SIZE_NEW 483

static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf)
{
        struct usb_host_config *config = dev->actconfig;
        int err;

        if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD ||
            le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_NEW) {
                dev_dbg(&dev->dev, "sending Extigy boot sequence...\n");
                /* Send message to force it to reconnect with full interface. */
                err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev,0),
                                      0x10, 0x43, 0x0001, 0x000a, NULL, 0);
                if (err < 0)
                        dev_dbg(&dev->dev, "error sending boot message: %d\n", err);
                err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
                                &dev->descriptor, sizeof(dev->descriptor));
                config = dev->actconfig;
                if (err < 0)
                        dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);
                err = usb_reset_configuration(dev);
                if (err < 0)
                        dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err);
                dev_dbg(&dev->dev, "extigy_boot: new boot length = %d\n",
                            le16_to_cpu(get_cfg_desc(config)->wTotalLength));
                return -ENODEV; /* quit this anyway */
        }
        return 0;
}

static int snd_usb_audigy2nx_boot_quirk(struct usb_device *dev)
{
        u8 buf = 1;

        snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), 0x2a,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
                        0, 0, &buf, 1);
        if (buf == 0) {
                snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0x29,
                                USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
                                1, 2000, NULL, 0);
                return -ENODEV;
        }
        return 0;
}

static int snd_usb_fasttrackpro_boot_quirk(struct usb_device *dev)
{
        int err;

        if (dev->actconfig->desc.bConfigurationValue == 1) {
                dev_info(&dev->dev,
                           "Fast Track Pro switching to config #2\n");
                /* This function has to be available by the usb core module.
                 * if it is not avialable the boot quirk has to be left out
                 * and the configuration has to be set by udev or hotplug
                 * rules
                 */
                err = usb_driver_set_configuration(dev, 2);
                if (err < 0)
                        dev_dbg(&dev->dev,
                                "error usb_driver_set_configuration: %d\n",
                                err);
                /* Always return an error, so that we stop creating a device
                   that will just be destroyed and recreated with a new
                   configuration */
                return -ENODEV;
        } else
                dev_info(&dev->dev, "Fast Track Pro config OK\n");

        return 0;
}

/*
 * C-Media CM106/CM106+ have four 16-bit internal registers that are nicely
 * documented in the device's data sheet.
 */
static int snd_usb_cm106_write_int_reg(struct usb_device *dev, int reg, u16 value)
{
        u8 buf[4];
        buf[0] = 0x20;
        buf[1] = value & 0xff;
        buf[2] = (value >> 8) & 0xff;
        buf[3] = reg;
        return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION,
                               USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
                               0, 0, &buf, 4);
}

static int snd_usb_cm106_boot_quirk(struct usb_device *dev)
{
        /*
         * Enable line-out driver mode, set headphone source to front
         * channels, enable stereo mic.
         */
        return snd_usb_cm106_write_int_reg(dev, 2, 0x8004);
}

/*
 * C-Media CM6206 is based on CM106 with two additional
 * registers that are not documented in the data sheet.
 * Values here are chosen based on sniffing USB traffic
 * under Windows.
 */
static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
{
        int err  = 0, reg;
        int val[] = {0x2004, 0x3000, 0xf800, 0x143f, 0x0000, 0x3000};

        for (reg = 0; reg < ARRAY_SIZE(val); reg++) {
                err = snd_usb_cm106_write_int_reg(dev, reg, val[reg]);
                if (err < 0)
                        return err;
        }

        return err;
}

/* quirk for Plantronics GameCom 780 with CM6302 chip */
static int snd_usb_gamecon780_boot_quirk(struct usb_device *dev)
{
        /* set the initial volume and don't change; other values are either
         * too loud or silent due to firmware bug (bko#65251)
         */
        u8 buf[2] = { 0x74, 0xe3 };
        return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
                        UAC_FU_VOLUME << 8, 9 << 8, buf, 2);
}

/*
 * Novation Twitch DJ controller
 * Focusrite Novation Saffire 6 USB audio card
 */
static int snd_usb_novation_boot_quirk(struct usb_device *dev)
{
        /* preemptively set up the device because otherwise the
         * raw MIDI endpoints are not active */
        usb_set_interface(dev, 0, 1);
        return 0;
}

/*
 * This call will put the synth in "USB send" mode, i.e it will send MIDI
 * messages through USB (this is disabled at startup). The synth will
 * acknowledge by sending a sysex on endpoint 0x85 and by displaying a USB
 * sign on its LCD. Values here are chosen based on sniffing USB traffic
 * under Windows.
 */
static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev)
{
        int err, actual_length;

        /* "midi send" enable */
        static const u8 seq[] = { 0x4e, 0x73, 0x52, 0x01 };

        void *buf = kmemdup(seq, ARRAY_SIZE(seq), GFP_KERNEL);
        if (!buf)
                return -ENOMEM;
        err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x05), buf,
                        ARRAY_SIZE(seq), &actual_length, 1000);
        kfree(buf);
        if (err < 0)
                return err;

        return 0;
}

/*
 * Some sound cards from Native Instruments are in fact compliant to the USB
 * audio standard of version 2 and other approved USB standards, even though
 * they come up as vendor-specific device when first connected.
 *
 * However, they can be told to come up with a new set of descriptors
 * upon their next enumeration, and the interfaces announced by the new
 * descriptors will then be handled by the kernel's class drivers. As the
 * product ID will also change, no further checks are required.
 */

static int snd_usb_nativeinstruments_boot_quirk(struct usb_device *dev)
{
        int ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                                  0xaf, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
                                  1, 0, NULL, 0, 1000);

        if (ret < 0)
                return ret;

        usb_reset_device(dev);

        /* return -EAGAIN, so the creation of an audio interface for this
         * temporary device is aborted. The device will reconnect with a
         * new product ID */
        return -EAGAIN;
}

static void mbox2_setup_48_24_magic(struct usb_device *dev)
{
        u8 srate[3];
        u8 temp[12];

        /* Choose 48000Hz permanently */
        srate[0] = 0x80;
        srate[1] = 0xbb;
        srate[2] = 0x00;

        /* Send the magic! */
        snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
                0x01, 0x22, 0x0100, 0x0085, &temp, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0085, &srate, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0086, &srate, 0x0003);
        snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0),
                0x81, 0xa2, 0x0100, 0x0003, &srate, 0x0003);
        return;
}

/* Digidesign Mbox 2 needs to load firmware onboard
 * and driver must wait a few seconds for initialisation.
 */

#define MBOX2_FIRMWARE_SIZE    646
#define MBOX2_BOOT_LOADING     0x01 /* Hard coded into the device */
#define MBOX2_BOOT_READY       0x02 /* Hard coded into the device */

static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
{
        struct usb_host_config *config = dev->actconfig;
        int err;
        u8 bootresponse[0x12];
        int fwsize;
        int count;

        fwsize = le16_to_cpu(get_cfg_desc(config)->wTotalLength);

        if (fwsize != MBOX2_FIRMWARE_SIZE) {
                dev_err(&dev->dev, "Invalid firmware size=%d.\n", fwsize);
                return -ENODEV;
        }

        dev_dbg(&dev->dev, "Sending Digidesign Mbox 2 boot sequence...\n");

        count = 0;
        bootresponse[0] = MBOX2_BOOT_LOADING;
        while ((bootresponse[0] == MBOX2_BOOT_LOADING) && (count < 10)) {
                msleep(500); /* 0.5 second delay */
                snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
                        /* Control magic - load onboard firmware */
                        0x85, 0xc0, 0x0001, 0x0000, &bootresponse, 0x0012);
                if (bootresponse[0] == MBOX2_BOOT_READY)
                        break;
                dev_dbg(&dev->dev, "device not ready, resending boot sequence...\n");
                count++;
        }

        if (bootresponse[0] != MBOX2_BOOT_READY) {
                dev_err(&dev->dev, "Unknown bootresponse=%d, or timed out, ignoring device.\n", bootresponse[0]);
                return -ENODEV;
        }

        dev_dbg(&dev->dev, "device initialised!\n");

        err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
                &dev->descriptor, sizeof(dev->descriptor));
        config = dev->actconfig;
        if (err < 0)
                dev_dbg(&dev->dev, "error usb_get_descriptor: %d\n", err);

        err = usb_reset_configuration(dev);
        if (err < 0)
                dev_dbg(&dev->dev, "error usb_reset_configuration: %d\n", err);
        dev_dbg(&dev->dev, "mbox2_boot: new boot length = %d\n",
                le16_to_cpu(get_cfg_desc(config)->wTotalLength));

        mbox2_setup_48_24_magic(dev);

        dev_info(&dev->dev, "Digidesign Mbox 2: 24bit 48kHz");

        return 0; /* Successful boot */
}

/*
 * Setup quirks
 */
#define MAUDIO_SET              0x01 /* parse device_setup */
#define MAUDIO_SET_COMPATIBLE   0x80 /* use only "win-compatible" interfaces */
#define MAUDIO_SET_DTS          0x02 /* enable DTS Digital Output */
#define MAUDIO_SET_96K          0x04 /* 48-96KHz rate if set, 8-48KHz otherwise */
#define MAUDIO_SET_24B          0x08 /* 24bits sample if set, 16bits otherwise */
#define MAUDIO_SET_DI           0x10 /* enable Digital Input */
#define MAUDIO_SET_MASK         0x1f /* bit mask for setup value */
#define MAUDIO_SET_24B_48K_DI    0x19 /* 24bits+48KHz+Digital Input */
#define MAUDIO_SET_24B_48K_NOTDI 0x09 /* 24bits+48KHz+No Digital Input */
#define MAUDIO_SET_16B_48K_DI    0x11 /* 16bits+48KHz+Digital Input */
#define MAUDIO_SET_16B_48K_NOTDI 0x01 /* 16bits+48KHz+No Digital Input */

static int quattro_skip_setting_quirk(struct snd_usb_audio *chip,
                                      int iface, int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);
        if (chip->setup & MAUDIO_SET) {
                if (chip->setup & MAUDIO_SET_COMPATIBLE) {
                        if (iface != 1 && iface != 2)
                                return 1; /* skip all interfaces but 1 and 2 */
                } else {
                        unsigned int mask;
                        if (iface == 1 || iface == 2)
                                return 1; /* skip interfaces 1 and 2 */
                        if ((chip->setup & MAUDIO_SET_96K) && altno != 1)
                                return 1; /* skip this altsetting */
                        mask = chip->setup & MAUDIO_SET_MASK;
                        if (mask == MAUDIO_SET_24B_48K_DI && altno != 2)
                                return 1; /* skip this altsetting */
                        if (mask == MAUDIO_SET_24B_48K_NOTDI && altno != 3)
                                return 1; /* skip this altsetting */
                        if (mask == MAUDIO_SET_16B_48K_NOTDI && altno != 4)
                                return 1; /* skip this altsetting */
                }
        }
        usb_audio_dbg(chip,
                    "using altsetting %d for interface %d config %d\n",
                    altno, iface, chip->setup);
        return 0; /* keep this altsetting */
}

static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
                                         int iface,
                                         int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);

        if (chip->setup & MAUDIO_SET) {
                unsigned int mask;
                if ((chip->setup & MAUDIO_SET_DTS) && altno != 6)
                        return 1; /* skip this altsetting */
                if ((chip->setup & MAUDIO_SET_96K) && altno != 1)
                        return 1; /* skip this altsetting */
                mask = chip->setup & MAUDIO_SET_MASK;
                if (mask == MAUDIO_SET_24B_48K_DI && altno != 2)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_24B_48K_NOTDI && altno != 3)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_16B_48K_DI && altno != 4)
                        return 1; /* skip this altsetting */
                if (mask == MAUDIO_SET_16B_48K_NOTDI && altno != 5)
                        return 1; /* skip this altsetting */
        }

        return 0; /* keep this altsetting */
}

static int fasttrackpro_skip_setting_quirk(struct snd_usb_audio *chip,
                                           int iface, int altno)
{
        /* Reset ALL ifaces to 0 altsetting.
         * Call it for every possible altsetting of every interface.
         */
        usb_set_interface(chip->dev, iface, 0);

        /* possible configuration where both inputs and only one output is
         *used is not supported by the current setup
         */
        if (chip->setup & (MAUDIO_SET | MAUDIO_SET_24B)) {
                if (chip->setup & MAUDIO_SET_96K) {
                        if (altno != 3 && altno != 6)
                                return 1;
                } else if (chip->setup & MAUDIO_SET_DI) {
                        if (iface == 4)
                                return 1; /* no analog input */
                        if (altno != 2 && altno != 5)
                                return 1; /* enable only altsets 2 and 5 */
                } else {
                        if (iface == 5)
                                return 1; /* disable digialt input */
                        if (altno != 2 && altno != 5)
                                return 1; /* enalbe only altsets 2 and 5 */
                }
        } else {
                /* keep only 16-Bit mode */
                if (altno != 1)
                        return 1;
        }

        usb_audio_dbg(chip,
                    "using altsetting %d for interface %d config %d\n",
                    altno, iface, chip->setup);
        return 0; /* keep this altsetting */
}

int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
                                  int iface,
                                  int altno)
{
        /* audiophile usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2003))
                return audiophile_skip_setting_quirk(chip, iface, altno);
        /* quattro usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2001))
                return quattro_skip_setting_quirk(chip, iface, altno);
        /* fasttrackpro usb: skip altsets incompatible with device_setup */
        if (chip->usb_id == USB_ID(0x0763, 0x2012))
                return fasttrackpro_skip_setting_quirk(chip, iface, altno);

        return 0;
}

int snd_usb_apply_boot_quirk(struct usb_device *dev,
                             struct usb_interface *intf,
                             const struct snd_usb_audio_quirk *quirk,
                             unsigned int id)
{
        switch (id) {
        case USB_ID(0x041e, 0x3000):
                /* SB Extigy needs special boot-up sequence */
                /* if more models come, this will go to the quirk list. */
                return snd_usb_extigy_boot_quirk(dev, intf);

        case USB_ID(0x041e, 0x3020):
                /* SB Audigy 2 NX needs its own boot-up magic, too */
                return snd_usb_audigy2nx_boot_quirk(dev);

        case USB_ID(0x10f5, 0x0200):
                /* C-Media CM106 / Turtle Beach Audio Advantage Roadie */
                return snd_usb_cm106_boot_quirk(dev);

        case USB_ID(0x0d8c, 0x0102):
                /* C-Media CM6206 / CM106-Like Sound Device */
        case USB_ID(0x0ccd, 0x00b1): /* Terratec Aureon 7.1 USB */
                return snd_usb_cm6206_boot_quirk(dev);

        case USB_ID(0x0dba, 0x3000):
                /* Digidesign Mbox 2 */
                return snd_usb_mbox2_boot_quirk(dev);

        case USB_ID(0x1235, 0x0010): /* Focusrite Novation Saffire 6 USB */
        case USB_ID(0x1235, 0x0018): /* Focusrite Novation Twitch */
                return snd_usb_novation_boot_quirk(dev);

        case USB_ID(0x133e, 0x0815):
                /* Access Music VirusTI Desktop */
                return snd_usb_accessmusic_boot_quirk(dev);

        case USB_ID(0x17cc, 0x1000): /* Komplete Audio 6 */
        case USB_ID(0x17cc, 0x1010): /* Traktor Audio 6 */
        case USB_ID(0x17cc, 0x1020): /* Traktor Audio 10 */
                return snd_usb_nativeinstruments_boot_quirk(dev);
        case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
                return snd_usb_fasttrackpro_boot_quirk(dev);
        case USB_ID(0x047f, 0xc010): /* Plantronics Gamecom 780 */
                return snd_usb_gamecon780_boot_quirk(dev);
        }

        return 0;
}

/*
 * check if the device uses big-endian samples
 */
int snd_usb_is_big_endian_format(struct snd_usb_audio *chip, struct audioformat *fp)
{
        /* it depends on altsetting whether the device is big-endian or not */
        switch (chip->usb_id) {
        case USB_ID(0x0763, 0x2001): /* M-Audio Quattro: captured data only */
                if (fp->altsetting == 2 || fp->altsetting == 3 ||
                        fp->altsetting == 5 || fp->altsetting == 6)
                        return 1;
                break;
        case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
                if (chip->setup == 0x00 ||
                        fp->altsetting == 1 || fp->altsetting == 2 ||
                        fp->altsetting == 3)
                        return 1;
                break;
        case USB_ID(0x0763, 0x2012): /* M-Audio Fast Track Pro */
                if (fp->altsetting == 2 || fp->altsetting == 3 ||
                        fp->altsetting == 5 || fp->altsetting == 6)
                        return 1;
                break;
        }
        return 0;
}

/*
 * For E-Mu 0404USB/0202USB/TrackerPre/0204 sample rate should be set for device,
 * not for interface.
 */

enum {
        EMU_QUIRK_SR_44100HZ = 0,
        EMU_QUIRK_SR_48000HZ,
        EMU_QUIRK_SR_88200HZ,
        EMU_QUIRK_SR_96000HZ,
        EMU_QUIRK_SR_176400HZ,
        EMU_QUIRK_SR_192000HZ
};

static void set_format_emu_quirk(struct snd_usb_substream *subs,
                                 struct audioformat *fmt)
{
        unsigned char emu_samplerate_id = 0;

        /* When capture is active
         * sample rate shouldn't be changed
         * by playback substream
         */
        if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
                if (subs->stream->substream[SNDRV_PCM_STREAM_CAPTURE].interface != -1)
                        return;
        }

        switch (fmt->rate_min) {
        case 48000:
                emu_samplerate_id = EMU_QUIRK_SR_48000HZ;
                break;
        case 88200:
                emu_samplerate_id = EMU_QUIRK_SR_88200HZ;
                break;
        case 96000:
                emu_samplerate_id = EMU_QUIRK_SR_96000HZ;
                break;
        case 176400:
                emu_samplerate_id = EMU_QUIRK_SR_176400HZ;
                break;
        case 192000:
                emu_samplerate_id = EMU_QUIRK_SR_192000HZ;
                break;
        default:
                emu_samplerate_id = EMU_QUIRK_SR_44100HZ;
                break;
        }
        snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
        subs->pkt_offset_adj = (emu_samplerate_id >= EMU_QUIRK_SR_176400HZ) ? 4 : 0;
}

void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
                              struct audioformat *fmt)
{
        switch (subs->stream->chip->usb_id) {
        case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
        case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
        case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
        case USB_ID(0x041e, 0x3f19): /* E-Mu 0204 USB */
                set_format_emu_quirk(subs, fmt);
                break;
        }
}

bool snd_usb_get_sample_rate_quirk(struct snd_usb_audio *chip)
{
        /* devices which do not support reading the sample rate. */
        switch (chip->usb_id) {
        case USB_ID(0x041E, 0x4080): /* Creative Live Cam VF0610 */
        case USB_ID(0x045E, 0x075D): /* MS Lifecam Cinema  */
        case USB_ID(0x045E, 0x076D): /* MS Lifecam HD-5000 */
        case USB_ID(0x045E, 0x076E): /* MS Lifecam HD-5001 */
        case USB_ID(0x045E, 0x076F): /* MS Lifecam HD-6000 */
        case USB_ID(0x045E, 0x0772): /* MS Lifecam Studio */
        case USB_ID(0x045E, 0x0779): /* MS Lifecam HD-3000 */
        case USB_ID(0x047F, 0x0415): /* Plantronics BT-300 */
        case USB_ID(0x047F, 0xAA05): /* Plantronics DA45 */
        case USB_ID(0x04D8, 0xFEEA): /* Benchmark DAC1 Pre */
        case USB_ID(0x0556, 0x0014): /* Phoenix Audio TMX320VC */
        case USB_ID(0x05A3, 0x9420): /* ELP HD USB Camera */
        case USB_ID(0x074D, 0x3553): /* Outlaw RR2150 (Micronas UAC3553B) */
        case USB_ID(0x1901, 0x0191): /* GE B850V3 CP2114 audio interface */
        case USB_ID(0x1de7, 0x0013): /* Phoenix Audio MT202exe */
        case USB_ID(0x1de7, 0x0014): /* Phoenix Audio TMX320 */
        case USB_ID(0x1de7, 0x0114): /* Phoenix Audio MT202pcs */
        case USB_ID(0x21B4, 0x0081): /* AudioQuest DragonFly */
                return true;
        }
        return false;
}

/* Marantz/Denon USB DACs need a vendor cmd to switch
 * between PCM and native DSD mode
 */
static bool is_marantz_denon_dac(unsigned int id)
{
        switch (id) {
        case USB_ID(0x154e, 0x1003): /* Denon DA-300USB */
        case USB_ID(0x154e, 0x3005): /* Marantz HD-DAC1 */
        case USB_ID(0x154e, 0x3006): /* Marantz SA-14S1 */
                return true;
        }
        return false;
}

int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
                              struct audioformat *fmt)
{
        struct usb_device *dev = subs->dev;
        int err;

        if (is_marantz_denon_dac(subs->stream->chip->usb_id)) {
                /* First switch to alt set 0, otherwise the mode switch cmd
                 * will not be accepted by the DAC
                 */
                err = usb_set_interface(dev, fmt->iface, 0);
                if (err < 0)
                        return err;

                mdelay(20); /* Delay needed after setting the interface */

                switch (fmt->altsetting) {
                case 2: /* DSD mode requested */
                case 1: /* PCM mode requested */
                        err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
                                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
                                              fmt->altsetting - 1, 1, NULL, 0);
                        if (err < 0)
                                return err;
                        break;
                }
                mdelay(20);
        }
        return 0;
}

void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep)
{
        /*
         * "Playback Design" products send bogus feedback data at the start
         * of the stream. Ignore them.
         */
        if (USB_ID_VENDOR(ep->chip->usb_id) == 0x23ba &&
            ep->type == SND_USB_ENDPOINT_TYPE_SYNC)
                ep->skip_packets = 4;

        /*
         * M-Audio Fast Track C400/C600 - when packets are not skipped, real
         * world latency varies by approx. +/- 50 frames (at 96KHz) each time
         * the stream is (re)started. When skipping packets 16 at endpoint
         * start up, the real world latency is stable within +/- 1 frame (also
         * across power cycles).
         */
        if ((ep->chip->usb_id == USB_ID(0x0763, 0x2030) ||
             ep->chip->usb_id == USB_ID(0x0763, 0x2031)) &&
            ep->type == SND_USB_ENDPOINT_TYPE_DATA)
                ep->skip_packets = 16;

        /* Work around devices that report unreasonable feedback data */
        if ((ep->chip->usb_id == USB_ID(0x0644, 0x8038) ||  /* TEAC UD-H01 */
             ep->chip->usb_id == USB_ID(0x1852, 0x5034)) && /* T+A Dac8 */
            ep->syncmaxsize == 4)
                ep->tenor_fb_quirk = 1;
}

void snd_usb_set_interface_quirk(struct usb_device *dev)
{
        struct snd_usb_audio *chip = dev_get_drvdata(&dev->dev);

        if (!chip)
                return;
        /*
         * "Playback Design" products need a 50ms delay after setting the
         * USB interface.
         */
        switch (USB_ID_VENDOR(chip->usb_id)) {
        case 0x23ba: /* Playback Design */
        case 0x0644: /* TEAC Corp. */
                mdelay(50);
                break;
        }
}

/* quirk applied after snd_usb_ctl_msg(); not applied during boot quirks */
void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
                           __u8 request, __u8 requesttype, __u16 value,
                           __u16 index, void *data, __u16 size)
{
        struct snd_usb_audio *chip = dev_get_drvdata(&dev->dev);

        if (!chip)
                return;
        /*
         * "Playback Design" products need a 20ms delay after each
         * class compliant request
         */
        if (USB_ID_VENDOR(chip->usb_id) == 0x23ba &&
            (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
                mdelay(20);

        /*
         * "TEAC Corp." products need a 20ms delay after each
         * class compliant request
         */
        if (USB_ID_VENDOR(chip->usb_id) == 0x0644 &&
            (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
                mdelay(20);

        /* Marantz/Denon devices with USB DAC functionality need a delay
         * after each class compliant request
         */
        if (is_marantz_denon_dac(chip->usb_id)
            && (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
                mdelay(20);

        /* Zoom R16/24 needs a tiny delay here, otherwise requests like
         * get/set frequency return as failed despite actually succeeding.
         */
        if (chip->usb_id == USB_ID(0x1686, 0x00dd) &&
            (requesttype & USB_TYPE_MASK) == USB_TYPE_CLASS)
                mdelay(1);
}

/*
 * snd_usb_interface_dsd_format_quirks() is called from format.c to
 * augment the PCM format bit-field for DSD types. The UAC standards
 * don't have a designated bit field to denote DSD-capable interfaces,
 * hence all hardware that is known to support this format has to be
 * listed here.
 */
u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
                                        struct audioformat *fp,
                                        unsigned int sample_bytes)
{
        /* Playback Designs */
        if (USB_ID_VENDOR(chip->usb_id) == 0x23ba) {
                switch (fp->altsetting) {
                case 1:
                        fp->dsd_dop = true;
                        return SNDRV_PCM_FMTBIT_DSD_U16_LE;
                case 2:
                        fp->dsd_bitrev = true;
                        return SNDRV_PCM_FMTBIT_DSD_U8;
                case 3:
                        fp->dsd_bitrev = true;
                        return SNDRV_PCM_FMTBIT_DSD_U16_LE;
                }
        }

        /* XMOS based USB DACs */
        switch (chip->usb_id) {
        case USB_ID(0x20b1, 0x3008): /* iFi Audio micro/nano iDSD */
        case USB_ID(0x20b1, 0x2008): /* Matrix Audio X-Sabre */
        case USB_ID(0x20b1, 0x300a): /* Matrix Audio Mini-i Pro */
        case USB_ID(0x22d9, 0x0416): /* OPPO HA-1 */
                if (fp->altsetting == 2)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                break;

        case USB_ID(0x20b1, 0x000a): /* Gustard DAC-X20U */
        case USB_ID(0x20b1, 0x2009): /* DIYINHK DSD DXD 384kHz USB to I2S/DSD */
        case USB_ID(0x20b1, 0x2023): /* JLsounds I2SoverUSB */
        case USB_ID(0x20b1, 0x3023): /* Aune X1S 32BIT/384 DSD DAC */
        case USB_ID(0x2616, 0x0106): /* PS Audio NuWave DAC */
                if (fp->altsetting == 3)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
                break;
        default:
                break;
        }

        /* Denon/Marantz devices with USB DAC functionality */
        if (is_marantz_denon_dac(chip->usb_id)) {
                if (fp->altsetting == 2)
                        return SNDRV_PCM_FMTBIT_DSD_U32_BE;
        }

        return 0;
}