// SPDX-License-Identifier: GPL-2.0-or-later
/*
 */


#include <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>
#include <linux/usb/audio-v3.h>

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

#include "usbaudio.h"
#include "card.h"
#include "proc.h"
#include "quirks.h"
#include "endpoint.h"
#include "pcm.h"
#include "helper.h"
#include "format.h"
#include "clock.h"
#include "stream.h"
#include "power.h"
#include "media.h"

static void audioformat_free(struct audioformat *fp)
{
        list_del(&fp->list); /* unlink for avoiding double-free */
        kfree(fp->rate_table);
        kfree(fp->chmap);
        kfree(fp);
}

/*
 * free a substream
 */
static void free_substream(struct snd_usb_substream *subs)
{
        struct audioformat *fp, *n;

        if (!subs->num_formats)
                return; /* not initialized */
        list_for_each_entry_safe(fp, n, &subs->fmt_list, list)
                audioformat_free(fp);
        kfree(subs->str_pd);
        snd_media_stream_delete(subs);
}


/*
 * free a usb stream instance
 */
static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
{
        free_substream(&stream->substream[0]);
        free_substream(&stream->substream[1]);
        list_del(&stream->list);
        kfree(stream);
}

static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
{
        struct snd_usb_stream *stream = pcm->private_data;
        if (stream) {
                stream->pcm = NULL;
                snd_usb_audio_stream_free(stream);
        }
}

/*
 * initialize the substream instance.
 */

static void snd_usb_init_substream(struct snd_usb_stream *as,
                                   int stream,
                                   struct audioformat *fp,
                                   struct snd_usb_power_domain *pd)
{
        struct snd_usb_substream *subs = &as->substream[stream];

        INIT_LIST_HEAD(&subs->fmt_list);
        spin_lock_init(&subs->lock);

        subs->stream = as;
        subs->direction = stream;
        subs->dev = as->chip->dev;
        subs->txfr_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_ALIGN_TRANSFER);
        subs->tx_length_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_TX_LENGTH);
        subs->speed = snd_usb_get_speed(subs->dev);
        subs->pkt_offset_adj = 0;
        subs->stream_offset_adj = 0;

        snd_usb_set_pcm_ops(as->pcm, stream);

        list_add_tail(&fp->list, &subs->fmt_list);
        subs->formats |= fp->formats;
        subs->num_formats++;
        subs->fmt_type = fp->fmt_type;
        subs->ep_num = fp->endpoint;
        if (fp->channels > subs->channels_max)
                subs->channels_max = fp->channels;

        if (pd) {
                subs->str_pd = pd;
                /* Initialize Power Domain to idle status D1 */
                snd_usb_power_domain_set(subs->stream->chip, pd,
                                         UAC3_PD_STATE_D1);
        }

        snd_usb_preallocate_buffer(subs);
}

/* kctl callbacks for usb-audio channel maps */
static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
                              struct snd_ctl_elem_info *uinfo)
{
        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
        struct snd_usb_substream *subs = info->private_data;

        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = subs->channels_max;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = SNDRV_CHMAP_LAST;
        return 0;
}

/* check whether a duplicated entry exists in the audiofmt list */
static bool have_dup_chmap(struct snd_usb_substream *subs,
                           struct audioformat *fp)
{
        struct audioformat *prev = fp;

        list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
                if (prev->chmap &&
                    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
                        return true;
        }
        return false;
}

static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
                             unsigned int size, unsigned int __user *tlv)
{
        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
        struct snd_usb_substream *subs = info->private_data;
        struct audioformat *fp;
        unsigned int __user *dst;
        int count = 0;

        if (size < 8)
                return -ENOMEM;
        if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
                return -EFAULT;
        size -= 8;
        dst = tlv + 2;
        list_for_each_entry(fp, &subs->fmt_list, list) {
                int i, ch_bytes;

                if (!fp->chmap)
                        continue;
                if (have_dup_chmap(subs, fp))
                        continue;
                /* copy the entry */
                ch_bytes = fp->chmap->channels * 4;
                if (size < 8 + ch_bytes)
                        return -ENOMEM;
                if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
                    put_user(ch_bytes, dst + 1))
                        return -EFAULT;
                dst += 2;
                for (i = 0; i < fp->chmap->channels; i++, dst++) {
                        if (put_user(fp->chmap->map[i], dst))
                                return -EFAULT;
                }

                count += 8 + ch_bytes;
                size -= 8 + ch_bytes;
        }
        if (put_user(count, tlv + 1))
                return -EFAULT;
        return 0;
}

static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
                             struct snd_ctl_elem_value *ucontrol)
{
        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
        struct snd_usb_substream *subs = info->private_data;
        struct snd_pcm_chmap_elem *chmap = NULL;
        int i = 0;

        if (subs->cur_audiofmt)
                chmap = subs->cur_audiofmt->chmap;
        if (chmap) {
                for (i = 0; i < chmap->channels; i++)
                        ucontrol->value.integer.value[i] = chmap->map[i];
        }
        for (; i < subs->channels_max; i++)
                ucontrol->value.integer.value[i] = 0;
        return 0;
}

/* create a chmap kctl assigned to the given USB substream */
static int add_chmap(struct snd_pcm *pcm, int stream,
                     struct snd_usb_substream *subs)
{
        struct audioformat *fp;
        struct snd_pcm_chmap *chmap;
        struct snd_kcontrol *kctl;
        int err;

        list_for_each_entry(fp, &subs->fmt_list, list)
                if (fp->chmap)
                        goto ok;
        /* no chmap is found */
        return 0;

 ok:
        err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
        if (err < 0)
                return err;

        /* override handlers */
        chmap->private_data = subs;
        kctl = chmap->kctl;
        kctl->info = usb_chmap_ctl_info;
        kctl->get = usb_chmap_ctl_get;
        kctl->tlv.c = usb_chmap_ctl_tlv;

        return 0;
}

/* convert from USB ChannelConfig bits to ALSA chmap element */
static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
                                                int protocol)
{
        static const unsigned int uac1_maps[] = {
                SNDRV_CHMAP_FL,         /* left front */
                SNDRV_CHMAP_FR,         /* right front */
                SNDRV_CHMAP_FC,         /* center front */
                SNDRV_CHMAP_LFE,        /* LFE */
                SNDRV_CHMAP_RL,         /* left surround */
                SNDRV_CHMAP_RR,         /* right surround */
                SNDRV_CHMAP_FLC,        /* left of center */
                SNDRV_CHMAP_FRC,        /* right of center */
                SNDRV_CHMAP_RC,         /* surround */
                SNDRV_CHMAP_SL,         /* side left */
                SNDRV_CHMAP_SR,         /* side right */
                SNDRV_CHMAP_TC,         /* top */
                0 /* terminator */
        };
        static const unsigned int uac2_maps[] = {
                SNDRV_CHMAP_FL,         /* front left */
                SNDRV_CHMAP_FR,         /* front right */
                SNDRV_CHMAP_FC,         /* front center */
                SNDRV_CHMAP_LFE,        /* LFE */
                SNDRV_CHMAP_RL,         /* back left */
                SNDRV_CHMAP_RR,         /* back right */
                SNDRV_CHMAP_FLC,        /* front left of center */
                SNDRV_CHMAP_FRC,        /* front right of center */
                SNDRV_CHMAP_RC,         /* back center */
                SNDRV_CHMAP_SL,         /* side left */
                SNDRV_CHMAP_SR,         /* side right */
                SNDRV_CHMAP_TC,         /* top center */
                SNDRV_CHMAP_TFL,        /* top front left */
                SNDRV_CHMAP_TFC,        /* top front center */
                SNDRV_CHMAP_TFR,        /* top front right */
                SNDRV_CHMAP_TRL,        /* top back left */
                SNDRV_CHMAP_TRC,        /* top back center */
                SNDRV_CHMAP_TRR,        /* top back right */
                SNDRV_CHMAP_TFLC,       /* top front left of center */
                SNDRV_CHMAP_TFRC,       /* top front right of center */
                SNDRV_CHMAP_LLFE,       /* left LFE */
                SNDRV_CHMAP_RLFE,       /* right LFE */
                SNDRV_CHMAP_TSL,        /* top side left */
                SNDRV_CHMAP_TSR,        /* top side right */
                SNDRV_CHMAP_BC,         /* bottom center */
                SNDRV_CHMAP_RLC,        /* back left of center */
                SNDRV_CHMAP_RRC,        /* back right of center */
                0 /* terminator */
        };
        struct snd_pcm_chmap_elem *chmap;
        const unsigned int *maps;
        int c;

        if (channels > ARRAY_SIZE(chmap->map))
                return NULL;

        chmap = kzalloc_obj(*chmap);
        if (!chmap)
                return NULL;

        maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
        chmap->channels = channels;
        c = 0;

        if (bits) {
                for (; bits && *maps; maps++, bits >>= 1) {
                        if (bits & 1)
                                chmap->map[c++] = *maps;
                        if (c == chmap->channels)
                                break;
                }
        } else {
                /* If we're missing wChannelConfig, then guess something
                    to make sure the channel map is not skipped entirely */
                if (channels == 1)
                        chmap->map[c++] = SNDRV_CHMAP_MONO;
                else
                        for (; c < channels && *maps; maps++)
                                chmap->map[c++] = *maps;
        }

        for (; c < channels; c++)
                chmap->map[c] = SNDRV_CHMAP_UNKNOWN;

        return chmap;
}

/* UAC3 device stores channels information in Cluster Descriptors */
static struct
snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
                                                                *cluster)
{
        unsigned int channels = cluster->bNrChannels;
        struct snd_pcm_chmap_elem *chmap;
        void *p = cluster;
        int len, c;

        if (channels > ARRAY_SIZE(chmap->map))
                return NULL;

        chmap = kzalloc_obj(*chmap);
        if (!chmap)
                return NULL;

        len = le16_to_cpu(cluster->wLength);
        c = 0;
        p += sizeof(*cluster);
        len -= sizeof(*cluster);

        while (len > 0 && (c < channels)) {
                struct uac3_cluster_segment_descriptor *cs_desc = p;
                u16 cs_len;
                u8 cs_type;

                if (len < sizeof(*cs_desc))
                        break;
                cs_len = le16_to_cpu(cs_desc->wLength);
                if (len < cs_len)
                        break;
                cs_type = cs_desc->bSegmentType;

                if (cs_type == UAC3_CHANNEL_INFORMATION) {
                        struct uac3_cluster_information_segment_descriptor *is = p;
                        unsigned char map;

                        if (cs_len < sizeof(*is))
                                break;

                        /*
                         * TODO: this conversion is not complete, update it
                         * after adding UAC3 values to asound.h
                         */
                        switch (is->bChRelationship) {
                        case UAC3_CH_MONO:
                                map = SNDRV_CHMAP_MONO;
                                break;
                        case UAC3_CH_LEFT:
                        case UAC3_CH_FRONT_LEFT:
                        case UAC3_CH_HEADPHONE_LEFT:
                                map = SNDRV_CHMAP_FL;
                                break;
                        case UAC3_CH_RIGHT:
                        case UAC3_CH_FRONT_RIGHT:
                        case UAC3_CH_HEADPHONE_RIGHT:
                                map = SNDRV_CHMAP_FR;
                                break;
                        case UAC3_CH_FRONT_CENTER:
                                map = SNDRV_CHMAP_FC;
                                break;
                        case UAC3_CH_FRONT_LEFT_OF_CENTER:
                                map = SNDRV_CHMAP_FLC;
                                break;
                        case UAC3_CH_FRONT_RIGHT_OF_CENTER:
                                map = SNDRV_CHMAP_FRC;
                                break;
                        case UAC3_CH_SIDE_LEFT:
                                map = SNDRV_CHMAP_SL;
                                break;
                        case UAC3_CH_SIDE_RIGHT:
                                map = SNDRV_CHMAP_SR;
                                break;
                        case UAC3_CH_BACK_LEFT:
                                map = SNDRV_CHMAP_RL;
                                break;
                        case UAC3_CH_BACK_RIGHT:
                                map = SNDRV_CHMAP_RR;
                                break;
                        case UAC3_CH_BACK_CENTER:
                                map = SNDRV_CHMAP_RC;
                                break;
                        case UAC3_CH_BACK_LEFT_OF_CENTER:
                                map = SNDRV_CHMAP_RLC;
                                break;
                        case UAC3_CH_BACK_RIGHT_OF_CENTER:
                                map = SNDRV_CHMAP_RRC;
                                break;
                        case UAC3_CH_TOP_CENTER:
                                map = SNDRV_CHMAP_TC;
                                break;
                        case UAC3_CH_TOP_FRONT_LEFT:
                                map = SNDRV_CHMAP_TFL;
                                break;
                        case UAC3_CH_TOP_FRONT_RIGHT:
                                map = SNDRV_CHMAP_TFR;
                                break;
                        case UAC3_CH_TOP_FRONT_CENTER:
                                map = SNDRV_CHMAP_TFC;
                                break;
                        case UAC3_CH_TOP_FRONT_LOC:
                                map = SNDRV_CHMAP_TFLC;
                                break;
                        case UAC3_CH_TOP_FRONT_ROC:
                                map = SNDRV_CHMAP_TFRC;
                                break;
                        case UAC3_CH_TOP_SIDE_LEFT:
                                map = SNDRV_CHMAP_TSL;
                                break;
                        case UAC3_CH_TOP_SIDE_RIGHT:
                                map = SNDRV_CHMAP_TSR;
                                break;
                        case UAC3_CH_TOP_BACK_LEFT:
                                map = SNDRV_CHMAP_TRL;
                                break;
                        case UAC3_CH_TOP_BACK_RIGHT:
                                map = SNDRV_CHMAP_TRR;
                                break;
                        case UAC3_CH_TOP_BACK_CENTER:
                                map = SNDRV_CHMAP_TRC;
                                break;
                        case UAC3_CH_BOTTOM_CENTER:
                                map = SNDRV_CHMAP_BC;
                                break;
                        case UAC3_CH_LOW_FREQUENCY_EFFECTS:
                                map = SNDRV_CHMAP_LFE;
                                break;
                        case UAC3_CH_LFE_LEFT:
                                map = SNDRV_CHMAP_LLFE;
                                break;
                        case UAC3_CH_LFE_RIGHT:
                                map = SNDRV_CHMAP_RLFE;
                                break;
                        case UAC3_CH_RELATIONSHIP_UNDEFINED:
                        default:
                                map = SNDRV_CHMAP_UNKNOWN;
                                break;
                        }
                        chmap->map[c++] = map;
                }
                p += cs_len;
                len -= cs_len;
        }

        if (channels < c)
                pr_err("%s: channel number mismatch\n", __func__);

        chmap->channels = channels;

        for (; c < channels; c++)
                chmap->map[c] = SNDRV_CHMAP_UNKNOWN;

        return chmap;
}

/*
 * add this endpoint to the chip instance.
 * if a stream with the same endpoint already exists, append to it.
 * if not, create a new pcm stream. note, fp is added to the substream
 * fmt_list and will be freed on the chip instance release. do not free
 * fp or do remove it from the substream fmt_list to avoid double-free.
 */
static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
                                      int stream,
                                      struct audioformat *fp,
                                      struct snd_usb_power_domain *pd)

{
        struct snd_usb_stream *as;
        struct snd_usb_substream *subs;
        struct snd_pcm *pcm;
        int err;

        list_for_each_entry(as, &chip->pcm_list, list) {
                if (as->fmt_type != fp->fmt_type)
                        continue;
                subs = &as->substream[stream];
                if (subs->ep_num == fp->endpoint) {
                        list_add_tail(&fp->list, &subs->fmt_list);
                        subs->num_formats++;
                        subs->formats |= fp->formats;
                        return 0;
                }
        }

        if (chip->card->registered)
                chip->need_delayed_register = true;

        /* look for an empty stream */
        list_for_each_entry(as, &chip->pcm_list, list) {
                if (as->fmt_type != fp->fmt_type)
                        continue;
                subs = &as->substream[stream];
                if (subs->ep_num)
                        continue;
                err = snd_pcm_new_stream(as->pcm, stream, 1);
                if (err < 0)
                        return err;
                snd_usb_init_substream(as, stream, fp, pd);
                return add_chmap(as->pcm, stream, subs);
        }

        /* create a new pcm */
        as = kzalloc_obj(*as);
        if (!as)
                return -ENOMEM;
        as->pcm_index = chip->pcm_devs;
        as->chip = chip;
        as->fmt_type = fp->fmt_type;
        err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
                          stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
                          stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
                          &pcm);
        if (err < 0) {
                kfree(as);
                return err;
        }
        as->pcm = pcm;
        pcm->private_data = as;
        pcm->private_free = snd_usb_audio_pcm_free;
        pcm->info_flags = 0;
        if (chip->pcm_devs > 0)
                scnprintf(pcm->name, sizeof(pcm->name), "USB Audio #%d",
                          chip->pcm_devs);
        else
                strscpy(pcm->name, "USB Audio");

        snd_usb_init_substream(as, stream, fp, pd);

        /*
         * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
         * fix to swap capture stream order in conf/cards/USB-audio.conf
         */
        if (chip->usb_id == USB_ID(0x0763, 0x2003))
                list_add(&as->list, &chip->pcm_list);
        else
                list_add_tail(&as->list, &chip->pcm_list);

        chip->pcm_devs++;

        snd_usb_proc_pcm_format_add(as);

        return add_chmap(pcm, stream, &as->substream[stream]);
}

int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
                             int stream,
                             struct audioformat *fp)
{
        return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
}

static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
                                       int stream,
                                       struct audioformat *fp,
                                       struct snd_usb_power_domain *pd)
{
        return __snd_usb_add_audio_stream(chip, stream, fp, pd);
}

static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
                                         struct usb_host_interface *alts,
                                         int protocol, int iface_no)
{
        /* parsed with a v1 header here. that's ok as we only look at the
         * header first which is the same for both versions */
        struct uac_iso_endpoint_descriptor *csep;
        struct usb_interface_descriptor *altsd = get_iface_desc(alts);
        int attributes = 0;

        csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);

        /* Creamware Noah has this descriptor after the 2nd endpoint */
        if (!csep && altsd->bNumEndpoints >= 2)
                csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);

        /*
         * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
         * bytes after the first endpoint, go search the entire interface.
         * Some devices have it directly *before* the standard endpoint.
         */
        if (!csep)
                csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);

        if (!csep || csep->bLength < 7 ||
            csep->bDescriptorSubtype != UAC_EP_GENERAL)
                goto error;

        if (protocol == UAC_VERSION_1) {
                attributes = csep->bmAttributes;
        } else if (protocol == UAC_VERSION_2) {
                struct uac2_iso_endpoint_descriptor *csep2 =
                        (struct uac2_iso_endpoint_descriptor *) csep;

                if (csep2->bLength < sizeof(*csep2))
                        goto error;
                attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;

                /* emulate the endpoint attributes of a v1 device */
                if (csep2->bmControls & UAC2_CONTROL_PITCH)
                        attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
        } else { /* UAC_VERSION_3 */
                struct uac3_iso_endpoint_descriptor *csep3 =
                        (struct uac3_iso_endpoint_descriptor *) csep;

                if (csep3->bLength < sizeof(*csep3))
                        goto error;
                /* emulate the endpoint attributes of a v1 device */
                if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
                        attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
        }

        return attributes;

 error:
        usb_audio_warn(chip,
                       "%u:%d : no or invalid class specific endpoint descriptor\n",
                       iface_no, altsd->bAlternateSetting);
        return 0;
}

/* find an input terminal descriptor (either UAC1 or UAC2) with the given
 * terminal id
 */
static void *
snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
                                       int terminal_id, int protocol)
{
        struct uac2_input_terminal_descriptor *term = NULL;

        while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
                                               ctrl_iface->extralen,
                                               term, UAC_INPUT_TERMINAL))) {
                if (!snd_usb_validate_audio_desc(term, protocol))
                        continue;
                if (term->bTerminalID == terminal_id)
                        return term;
        }

        return NULL;
}

static void *
snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
                                        int terminal_id, int protocol)
{
        /* OK to use with both UAC2 and UAC3 */
        struct uac2_output_terminal_descriptor *term = NULL;

        while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
                                               ctrl_iface->extralen,
                                               term, UAC_OUTPUT_TERMINAL))) {
                if (!snd_usb_validate_audio_desc(term, protocol))
                        continue;
                if (term->bTerminalID == terminal_id)
                        return term;
        }

        return NULL;
}

static struct audioformat *
audio_format_alloc_init(struct snd_usb_audio *chip,
                       struct usb_host_interface *alts,
                       int protocol, int iface_no, int altset_idx,
                       int altno, int num_channels, int clock)
{
        struct usb_host_endpoint *ep = &alts->endpoint[0];
        struct audioformat *fp;

        fp = kzalloc_obj(*fp);
        if (!fp)
                return NULL;

        fp->iface = iface_no;
        fp->altsetting = altno;
        fp->altset_idx = altset_idx;
        fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
        fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
        fp->datainterval = snd_usb_parse_datainterval(chip, alts);
        fp->protocol = protocol;
        fp->maxpacksize = usb_endpoint_max_periodic_payload(chip->dev, ep);
        fp->channels = num_channels;
        fp->clock = clock;
        INIT_LIST_HEAD(&fp->list);

        return fp;
}

static struct audioformat *
snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
                              struct usb_host_interface *alts,
                              int protocol, int iface_no, int altset_idx,
                              int altno, int stream, int bm_quirk)
{
        struct usb_device *dev = chip->dev;
        struct uac_format_type_i_continuous_descriptor *fmt;
        unsigned int num_channels = 0, chconfig = 0;
        struct usb_host_interface *ctrl_intf;
        struct audioformat *fp;
        int clock = 0;
        u64 format;

        ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);

        /* get audio formats */
        if (protocol == UAC_VERSION_1) {
                struct uac1_as_header_descriptor *as =
                        snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                                NULL, UAC_AS_GENERAL);
                struct uac_input_terminal_descriptor *iterm;

                if (!as) {
                        dev_err(&dev->dev,
                                "%u:%d : UAC_AS_GENERAL descriptor not found\n",
                                iface_no, altno);
                        return NULL;
                }

                if (as->bLength < sizeof(*as)) {
                        dev_err(&dev->dev,
                                "%u:%d : invalid UAC_AS_GENERAL desc\n",
                                iface_no, altno);
                        return NULL;
                }

                format = le16_to_cpu(as->wFormatTag); /* remember the format value */

                iterm = snd_usb_find_input_terminal_descriptor(ctrl_intf,
                                                               as->bTerminalLink,
                                                               protocol);
                if (iterm) {
                        num_channels = iterm->bNrChannels;
                        chconfig = le16_to_cpu(iterm->wChannelConfig);
                }
        } else { /* UAC_VERSION_2 */
                struct uac2_input_terminal_descriptor *input_term;
                struct uac2_output_terminal_descriptor *output_term;
                struct uac2_as_header_descriptor *as =
                        snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                                NULL, UAC_AS_GENERAL);

                if (!as) {
                        dev_err(&dev->dev,
                                "%u:%d : UAC_AS_GENERAL descriptor not found\n",
                                iface_no, altno);
                        return NULL;
                }

                if (as->bLength < sizeof(*as)) {
                        dev_err(&dev->dev,
                                "%u:%d : invalid UAC_AS_GENERAL desc\n",
                                iface_no, altno);
                        return NULL;
                }

                num_channels = as->bNrChannels;
                format = le32_to_cpu(as->bmFormats);
                chconfig = le32_to_cpu(as->bmChannelConfig);

                /*
                 * lookup the terminal associated to this interface
                 * to extract the clock
                 */
                input_term = snd_usb_find_input_terminal_descriptor(ctrl_intf,
                                                                    as->bTerminalLink,
                                                                    protocol);
                if (input_term) {
                        clock = input_term->bCSourceID;
                        if (!chconfig && (num_channels == input_term->bNrChannels))
                                chconfig = le32_to_cpu(input_term->bmChannelConfig);
                        goto found_clock;
                }

                output_term = snd_usb_find_output_terminal_descriptor(ctrl_intf,
                                                                      as->bTerminalLink,
                                                                      protocol);
                if (output_term) {
                        clock = output_term->bCSourceID;
                        goto found_clock;
                }

                dev_err(&dev->dev,
                        "%u:%d : bogus bTerminalLink %d\n",
                        iface_no, altno, as->bTerminalLink);
                return NULL;
        }

found_clock:
        /* get format type */
        fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                      NULL, UAC_FORMAT_TYPE);
        if (!fmt) {
                dev_err(&dev->dev,
                        "%u:%d : no UAC_FORMAT_TYPE desc\n",
                        iface_no, altno);
                return NULL;
        }
        if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
                        || ((protocol == UAC_VERSION_2) &&
                                        (fmt->bLength < 6))) {
                dev_err(&dev->dev,
                        "%u:%d : invalid UAC_FORMAT_TYPE desc\n",
                        iface_no, altno);
                return NULL;
        }

        /*
         * Blue Microphones workaround: The last altsetting is
         * identical with the previous one, except for a larger
         * packet size, but is actually a mislabeled two-channel
         * setting; ignore it.
         *
         * Part 2: analyze quirk flag and format
         */
        if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
                return NULL;

        fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
                                     altset_idx, altno, num_channels, clock);
        if (!fp)
                return ERR_PTR(-ENOMEM);

        fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
                                                       iface_no);

        /* some quirks for attributes here */
        snd_usb_audioformat_attributes_quirk(chip, fp, stream);

        /* ok, let's parse further... */
        if (snd_usb_parse_audio_format(chip, fp, format,
                                        fmt, stream) < 0) {
                audioformat_free(fp);
                return NULL;
        }

        /* Create chmap */
        if (fp->channels != num_channels)
                chconfig = 0;

        fp->chmap = convert_chmap(fp->channels, chconfig, protocol);

        return fp;
}

static struct audioformat *
snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
                             struct usb_host_interface *alts,
                             struct snd_usb_power_domain **pd_out,
                             int iface_no, int altset_idx,
                             int altno, int stream)
{
        struct usb_device *dev = chip->dev;
        struct uac3_input_terminal_descriptor *input_term;
        struct uac3_output_terminal_descriptor *output_term;
        struct uac3_cluster_header_descriptor *cluster;
        struct uac3_as_header_descriptor *as = NULL;
        struct uac3_hc_descriptor_header hc_header;
        struct usb_host_interface *ctrl_intf;
        struct snd_pcm_chmap_elem *chmap;
        struct snd_usb_power_domain *pd;
        unsigned char badd_profile;
        u64 badd_formats = 0;
        unsigned int num_channels;
        struct audioformat *fp;
        u16 cluster_id, wLength, cluster_wLength;
        int clock = 0;
        int err;

        badd_profile = chip->badd_profile;
        ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);

        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
                unsigned int maxpacksize =
                        le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);

                switch (maxpacksize) {
                default:
                        dev_err(&dev->dev,
                                "%u:%d : incorrect wMaxPacketSize for BADD profile\n",
                                iface_no, altno);
                        return NULL;
                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
                        num_channels = 1;
                        break;
                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
                        num_channels = 1;
                        break;
                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
                        num_channels = 2;
                        break;
                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
                        num_channels = 2;
                        break;
                }

                chmap = kzalloc_obj(*chmap);
                if (!chmap)
                        return ERR_PTR(-ENOMEM);

                if (num_channels == 1) {
                        chmap->map[0] = SNDRV_CHMAP_MONO;
                } else {
                        chmap->map[0] = SNDRV_CHMAP_FL;
                        chmap->map[1] = SNDRV_CHMAP_FR;
                }

                chmap->channels = num_channels;
                clock = UAC3_BADD_CS_ID9;
                goto found_clock;
        }

        as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                     NULL, UAC_AS_GENERAL);
        if (!as) {
                dev_err(&dev->dev,
                        "%u:%d : UAC_AS_GENERAL descriptor not found\n",
                        iface_no, altno);
                return NULL;
        }

        if (as->bLength < sizeof(*as)) {
                dev_err(&dev->dev,
                        "%u:%d : invalid UAC_AS_GENERAL desc\n",
                        iface_no, altno);
                return NULL;
        }

        cluster_id = le16_to_cpu(as->wClusterDescrID);
        if (!cluster_id) {
                dev_err(&dev->dev,
                        "%u:%d : no cluster descriptor\n",
                        iface_no, altno);
                return NULL;
        }

        /*
         * Get number of channels and channel map through
         * High Capability Cluster Descriptor
         *
         * First step: get High Capability header and
         * read size of Cluster Descriptor
         */
        err = snd_usb_ctl_msg(chip->dev,
                        usb_rcvctrlpipe(chip->dev, 0),
                        UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
                        cluster_id,
                        snd_usb_ctrl_intf(ctrl_intf),
                        &hc_header, sizeof(hc_header));
        if (err < 0)
                return ERR_PTR(err);
        else if (err != sizeof(hc_header)) {
                dev_err(&dev->dev,
                        "%u:%d : can't get High Capability descriptor\n",
                        iface_no, altno);
                return ERR_PTR(-EIO);
        }

        /*
         * Second step: allocate needed amount of memory
         * and request Cluster Descriptor
         */
        wLength = le16_to_cpu(hc_header.wLength);
        if (wLength < sizeof(cluster))
                return NULL;
        cluster = kzalloc(wLength, GFP_KERNEL);
        if (!cluster)
                return ERR_PTR(-ENOMEM);
        err = snd_usb_ctl_msg(chip->dev,
                        usb_rcvctrlpipe(chip->dev, 0),
                        UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
                        cluster_id,
                        snd_usb_ctrl_intf(ctrl_intf),
                        cluster, wLength);
        if (err < 0) {
                kfree(cluster);
                return ERR_PTR(err);
        } else if (err != wLength) {
                dev_err(&dev->dev,
                        "%u:%d : can't get Cluster Descriptor\n",
                        iface_no, altno);
                kfree(cluster);
                return ERR_PTR(-EIO);
        }

        cluster_wLength = le16_to_cpu(cluster->wLength);
        if (cluster_wLength < sizeof(*cluster) ||
            cluster_wLength > wLength) {
                dev_err(&dev->dev,
                        "%u:%d : invalid Cluster Descriptor size\n",
                        iface_no, altno);
                kfree(cluster);
                return ERR_PTR(-EIO);
        }

        num_channels = cluster->bNrChannels;
        chmap = convert_chmap_v3(cluster);
        kfree(cluster);

        /*
         * lookup the terminal associated to this interface
         * to extract the clock
         */
        input_term = snd_usb_find_input_terminal_descriptor(ctrl_intf,
                                                            as->bTerminalLink,
                                                            UAC_VERSION_3);
        if (input_term) {
                clock = input_term->bCSourceID;
                goto found_clock;
        }

        output_term = snd_usb_find_output_terminal_descriptor(ctrl_intf,
                                                              as->bTerminalLink,
                                                              UAC_VERSION_3);
        if (output_term) {
                clock = output_term->bCSourceID;
                goto found_clock;
        }

        dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
                        iface_no, altno, as->bTerminalLink);
        kfree(chmap);
        return NULL;

found_clock:
        fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
                                     altset_idx, altno, num_channels, clock);
        if (!fp) {
                kfree(chmap);
                return ERR_PTR(-ENOMEM);
        }

        fp->chmap = chmap;

        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
                fp->attributes = 0; /* No attributes */

                fp->fmt_type = UAC_FORMAT_TYPE_I;
                fp->formats = badd_formats;

                fp->nr_rates = 0;       /* SNDRV_PCM_RATE_CONTINUOUS */
                fp->rate_min = UAC3_BADD_SAMPLING_RATE;
                fp->rate_max = UAC3_BADD_SAMPLING_RATE;
                fp->rates = SNDRV_PCM_RATE_CONTINUOUS;

                pd = kzalloc_obj(*pd);
                if (!pd) {
                        audioformat_free(fp);
                        return NULL;
                }
                pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
                                        UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
                pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
                pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
                pd->ctrl_iface = ctrl_intf;

        } else {
                fp->attributes = parse_uac_endpoint_attributes(chip, alts,
                                                               UAC_VERSION_3,
                                                               iface_no);

                pd = snd_usb_find_power_domain(ctrl_intf,
                                               as->bTerminalLink);

                /* ok, let's parse further... */
                if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
                        kfree(pd);
                        audioformat_free(fp);
                        return NULL;
                }
        }

        if (pd)
                *pd_out = pd;

        return fp;
}

static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
                                           int iface_no,
                                           bool *has_non_pcm, bool non_pcm)
{
        struct usb_device *dev;
        struct usb_interface *iface;
        struct usb_host_interface *alts;
        struct usb_interface_descriptor *altsd;
        int i, altno, err, stream;
        struct audioformat *fp = NULL;
        struct snd_usb_power_domain *pd = NULL;
        bool set_iface_first;
        int num, protocol;

        dev = chip->dev;

        /* parse the interface's altsettings */
        iface = usb_ifnum_to_if(dev, iface_no);

        num = iface->num_altsetting;

        /*
         * Dallas DS4201 workaround: It presents 5 altsettings, but the last
         * one misses syncpipe, and does not produce any sound.
         */
        if (chip->usb_id == USB_ID(0x04fa, 0x4201) && num >= 4)
                num = 4;

        for (i = 0; i < num; i++) {
                alts = &iface->altsetting[i];
                altsd = get_iface_desc(alts);
                protocol = altsd->bInterfaceProtocol;
                /* skip invalid one */
                if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
                      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
                       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
                     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
                    altsd->bNumEndpoints < 1 ||
                    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
                        continue;
                /* must be isochronous */
                if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
                    USB_ENDPOINT_XFER_ISOC)
                        continue;
                /* check direction */
                stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
                        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
                altno = altsd->bAlternateSetting;

                if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
                        continue;

                /*
                 * Roland audio streaming interfaces are marked with protocols
                 * 0/1/2, but are UAC 1 compatible.
                 */
                if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
                    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
                    protocol <= 2)
                        protocol = UAC_VERSION_1;

                switch (protocol) {
                default:
                        dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
                                iface_no, altno, protocol);
                        protocol = UAC_VERSION_1;
                        fallthrough;
                case UAC_VERSION_1:
                case UAC_VERSION_2: {
                        int bm_quirk = 0;

                        /*
                         * Blue Microphones workaround: The last altsetting is
                         * identical with the previous one, except for a larger
                         * packet size, but is actually a mislabeled two-channel
                         * setting; ignore it.
                         *
                         * Part 1: prepare quirk flag
                         */
                        if (altno == 2 && num == 3 &&
                            fp && fp->altsetting == 1 && fp->channels == 1 &&
                            fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
                            protocol == UAC_VERSION_1 &&
                            le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
                                                        fp->maxpacksize * 2)
                                bm_quirk = 1;

                        fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
                                                           iface_no, i, altno,
                                                           stream, bm_quirk);
                        break;
                }
                case UAC_VERSION_3:
                        fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
                                                iface_no, i, altno, stream);
                        break;
                }

                if (!fp)
                        continue;
                else if (IS_ERR(fp))
                        return PTR_ERR(fp);

                if (fp->fmt_type != UAC_FORMAT_TYPE_I)
                        *has_non_pcm = true;
                if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
                        audioformat_free(fp);
                        kfree(pd);
                        fp = NULL;
                        pd = NULL;
                        continue;
                }

                snd_usb_audioformat_set_sync_ep(chip, fp);

                dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
                if (protocol == UAC_VERSION_3)
                        err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
                else
                        err = snd_usb_add_audio_stream(chip, stream, fp);

                if (err < 0) {
                        audioformat_free(fp);
                        kfree(pd);
                        return err;
                }

                /* add endpoints */
                err = snd_usb_add_endpoint(chip, fp->endpoint,
                                           SND_USB_ENDPOINT_TYPE_DATA);
                if (err < 0)
                        return err;

                if (fp->sync_ep) {
                        err = snd_usb_add_endpoint(chip, fp->sync_ep,
                                                   fp->implicit_fb ?
                                                   SND_USB_ENDPOINT_TYPE_DATA :
                                                   SND_USB_ENDPOINT_TYPE_SYNC);
                        if (err < 0)
                                return err;
                }

                set_iface_first = false;
                if (protocol == UAC_VERSION_1 ||
                    (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST))
                        set_iface_first = true;

                /* try to set the interface... */
                if (chip->quirk_flags & QUIRK_FLAG_SKIP_IFACE_SETUP)
                        continue;

                usb_set_interface(chip->dev, iface_no, 0);
                if (set_iface_first)
                        usb_set_interface(chip->dev, iface_no, altno);
                snd_usb_init_pitch(chip, fp);
                snd_usb_init_sample_rate(chip, fp, fp->rate_max);
                if (!set_iface_first)
                        usb_set_interface(chip->dev, iface_no, altno);
        }
        return 0;
}

int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
{
        int err;
        bool has_non_pcm = false;

        /* parse PCM formats */
        err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
        if (err < 0)
                return err;

        if (has_non_pcm) {
                /* parse non-PCM formats */
                err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
                if (err < 0)
                        return err;
        }

        return 0;
}