// SPDX-License-Identifier: GPL-2.0-or-later
//
// Special handling for implicit feedback mode
//

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

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>

#include "usbaudio.h"
#include "card.h"
#include "helper.h"
#include "pcm.h"
#include "implicit.h"

enum {
        IMPLICIT_FB_NONE,
        IMPLICIT_FB_GENERIC,
        IMPLICIT_FB_FIXED,
        IMPLICIT_FB_BOTH,       /* generic playback + capture (for BOSS) */
};

struct snd_usb_implicit_fb_match {
        unsigned int id;
        unsigned int iface_class;
        unsigned int ep_num;
        unsigned int iface;
        int type;
};

#define IMPLICIT_FB_GENERIC_DEV(vend, prod) \
        { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_GENERIC }
#define IMPLICIT_FB_FIXED_DEV(vend, prod, ep, ifnum) \
        { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_FIXED, .ep_num = (ep),\
            .iface = (ifnum) }
#define IMPLICIT_FB_BOTH_DEV(vend, prod, ep, ifnum) \
        { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_BOTH, .ep_num = (ep),\
            .iface = (ifnum) }
#define IMPLICIT_FB_SKIP_DEV(vend, prod) \
        { .id = USB_ID(vend, prod), .type = IMPLICIT_FB_NONE }

/* Implicit feedback quirk table for playback */
static const struct snd_usb_implicit_fb_match playback_implicit_fb_quirks[] = {
        /* Fixed EP */
        /* FIXME: check the availability of generic matching */
        IMPLICIT_FB_FIXED_DEV(0x0763, 0x2030, 0x81, 3), /* M-Audio Fast Track C400 */
        IMPLICIT_FB_FIXED_DEV(0x0763, 0x2031, 0x81, 3), /* M-Audio Fast Track C600 */
        IMPLICIT_FB_FIXED_DEV(0x0763, 0x2080, 0x81, 2), /* M-Audio FastTrack Ultra */
        IMPLICIT_FB_FIXED_DEV(0x0763, 0x2081, 0x81, 2), /* M-Audio FastTrack Ultra */
        IMPLICIT_FB_FIXED_DEV(0x2466, 0x8010, 0x81, 2), /* Fractal Audio Axe-Fx III */
        IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0001, 0x81, 2), /* Solid State Logic SSL2 */
        IMPLICIT_FB_FIXED_DEV(0x31e9, 0x0002, 0x81, 2), /* Solid State Logic SSL2+ */
        IMPLICIT_FB_FIXED_DEV(0x0499, 0x172f, 0x81, 2), /* Steinberg UR22C */
        IMPLICIT_FB_FIXED_DEV(0x0d9a, 0x00df, 0x81, 2), /* RTX6001 */
        IMPLICIT_FB_FIXED_DEV(0x19f7, 0x000a, 0x84, 3), /* RODE AI-1 */
        IMPLICIT_FB_FIXED_DEV(0x22f0, 0x0006, 0x81, 3), /* Allen&Heath Qu-16 */
        IMPLICIT_FB_FIXED_DEV(0x1686, 0xf029, 0x82, 2), /* Zoom UAC-2 */
        IMPLICIT_FB_FIXED_DEV(0x2466, 0x8003, 0x86, 2), /* Fractal Audio Axe-Fx II */
        IMPLICIT_FB_FIXED_DEV(0x0499, 0x172a, 0x86, 2), /* Yamaha MODX */

        /* Special matching */
        { .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_AUDIO,
          .type = IMPLICIT_FB_NONE },           /* MicroBook IIc */
        /* ep = 0x84, ifnum = 0 */
        { .id = USB_ID(0x07fd, 0x0004), .iface_class = USB_CLASS_VENDOR_SPEC,
          .type = IMPLICIT_FB_FIXED,
          .ep_num = 0x84, .iface = 0 },         /* MOTU MicroBook II */

        {} /* terminator */
};

/* Implicit feedback quirk table for capture: only FIXED type */
static const struct snd_usb_implicit_fb_match capture_implicit_fb_quirks[] = {
        {} /* terminator */
};

/* set up sync EP information on the audioformat */
static int add_implicit_fb_sync_ep(struct snd_usb_audio *chip,
                                   struct audioformat *fmt,
                                   int ep, int ep_idx, int ifnum,
                                   const struct usb_host_interface *alts)
{
        struct usb_interface *iface;

        if (!alts) {
                iface = usb_ifnum_to_if(chip->dev, ifnum);
                if (!iface || iface->num_altsetting < 2)
                        return 0;
                alts = &iface->altsetting[1];
        }

        fmt->sync_ep = ep;
        fmt->sync_iface = ifnum;
        fmt->sync_altsetting = alts->desc.bAlternateSetting;
        fmt->sync_ep_idx = ep_idx;
        fmt->implicit_fb = 1;
        usb_audio_dbg(chip,
                      "%d:%d: added %s implicit_fb sync_ep %x, iface %d:%d\n",
                      fmt->iface, fmt->altsetting,
                      (ep & USB_DIR_IN) ? "playback" : "capture",
                      fmt->sync_ep, fmt->sync_iface, fmt->sync_altsetting);
        return 1;
}

/* Check whether the given UAC2 iface:altset points to an implicit fb source */
static int add_generic_uac2_implicit_fb(struct snd_usb_audio *chip,
                                        struct audioformat *fmt,
                                        unsigned int ifnum,
                                        unsigned int altsetting)
{
        struct usb_host_interface *alts;
        struct usb_endpoint_descriptor *epd;

        alts = snd_usb_get_host_interface(chip, ifnum, altsetting);
        if (!alts)
                return 0;
        if (alts->desc.bInterfaceClass != USB_CLASS_AUDIO ||
            alts->desc.bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING ||
            alts->desc.bInterfaceProtocol != UAC_VERSION_2 ||
            alts->desc.bNumEndpoints < 1)
                return 0;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_in(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
                                        USB_ENDPOINT_USAGE_IMPLICIT_FB)
                return 0;
        return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
                                       ifnum, alts);
}

static bool roland_sanity_check_iface(struct usb_host_interface *alts)
{
        if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
            (alts->desc.bInterfaceSubClass != 2 &&
             alts->desc.bInterfaceProtocol != 2) ||
            alts->desc.bNumEndpoints < 1)
                return false;
        return true;
}

/* Like the UAC2 case above, but specific to Roland with vendor class and hack */
static int add_roland_implicit_fb(struct snd_usb_audio *chip,
                                  struct audioformat *fmt,
                                  struct usb_host_interface *alts)
{
        struct usb_endpoint_descriptor *epd;

        if (!roland_sanity_check_iface(alts))
                return 0;
        /* only when both streams are with ASYNC type */
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_out(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return 0;

        /* check capture EP */
        alts = snd_usb_get_host_interface(chip,
                                          alts->desc.bInterfaceNumber + 1,
                                          alts->desc.bAlternateSetting);
        if (!alts || !roland_sanity_check_iface(alts))
                return 0;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_in(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return 0;
        chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
        return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
                                       alts->desc.bInterfaceNumber, alts);
}

/* capture quirk for Roland device; always full-duplex */
static int add_roland_capture_quirk(struct snd_usb_audio *chip,
                                    struct audioformat *fmt,
                                    struct usb_host_interface *alts)
{
        struct usb_endpoint_descriptor *epd;

        if (!roland_sanity_check_iface(alts))
                return 0;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_in(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return 0;

        alts = snd_usb_get_host_interface(chip,
                                          alts->desc.bInterfaceNumber - 1,
                                          alts->desc.bAlternateSetting);
        if (!alts || !roland_sanity_check_iface(alts))
                return 0;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_out(epd))
                return 0;
        return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
                                       alts->desc.bInterfaceNumber, alts);
}

/* Playback and capture EPs on Pioneer devices share the same iface/altset
 * for the implicit feedback operation
 */
static bool is_pioneer_implicit_fb(struct snd_usb_audio *chip,
                                   struct usb_host_interface *alts)

{
        struct usb_endpoint_descriptor *epd;

        if (USB_ID_VENDOR(chip->usb_id) != 0x2b73 &&
            USB_ID_VENDOR(chip->usb_id) != 0x08e4)
                return false;
        if (alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
                return false;
        if (alts->desc.bNumEndpoints != 2)
                return false;

        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_out(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return false;

        epd = get_endpoint(alts, 1);
        if (!usb_endpoint_is_isoc_in(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC ||
            ((epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
             USB_ENDPOINT_USAGE_DATA &&
             (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
             USB_ENDPOINT_USAGE_IMPLICIT_FB))
                return false;

        return true;
}

static int __add_generic_implicit_fb(struct snd_usb_audio *chip,
                                     struct audioformat *fmt,
                                     int iface, int altset)
{
        struct usb_host_interface *alts;
        struct usb_endpoint_descriptor *epd;

        alts = snd_usb_get_host_interface(chip, iface, altset);
        if (!alts)
                return 0;

        if ((alts->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC &&
             alts->desc.bInterfaceClass != USB_CLASS_AUDIO) ||
            alts->desc.bNumEndpoints < 1)
                return 0;
        epd = get_endpoint(alts, 0);
        if (!usb_endpoint_is_isoc_in(epd) ||
            (epd->bmAttributes & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return 0;
        return add_implicit_fb_sync_ep(chip, fmt, epd->bEndpointAddress, 0,
                                       iface, alts);
}

/* More generic quirk: look for the sync EP next to the data EP */
static int add_generic_implicit_fb(struct snd_usb_audio *chip,
                                   struct audioformat *fmt,
                                   struct usb_host_interface *alts)
{
        if ((fmt->ep_attr & USB_ENDPOINT_SYNCTYPE) != USB_ENDPOINT_SYNC_ASYNC)
                return 0;

        if (__add_generic_implicit_fb(chip, fmt,
                                      alts->desc.bInterfaceNumber + 1,
                                      alts->desc.bAlternateSetting))
                return 1;
        return __add_generic_implicit_fb(chip, fmt,
                                         alts->desc.bInterfaceNumber - 1,
                                         alts->desc.bAlternateSetting);
}

static const struct snd_usb_implicit_fb_match *
find_implicit_fb_entry(struct snd_usb_audio *chip,
                       const struct snd_usb_implicit_fb_match *match,
                       const struct usb_host_interface *alts)
{
        for (; match->id; match++)
                if (match->id == chip->usb_id &&
                    (!match->iface_class ||
                     (alts->desc.bInterfaceClass == match->iface_class)))
                        return match;

        return NULL;
}

/* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
 * applies. Returns 1 if a quirk was found.
 */
static int audioformat_implicit_fb_quirk(struct snd_usb_audio *chip,
                                         struct audioformat *fmt,
                                         struct usb_host_interface *alts)
{
        const struct snd_usb_implicit_fb_match *p;
        unsigned int attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;

        p = find_implicit_fb_entry(chip, playback_implicit_fb_quirks, alts);
        if (p) {
                switch (p->type) {
                case IMPLICIT_FB_GENERIC:
                        return add_generic_implicit_fb(chip, fmt, alts);
                case IMPLICIT_FB_NONE:
                        return 0; /* No quirk */
                case IMPLICIT_FB_FIXED:
                        return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
                                                       p->iface, NULL);
                }
        }

        /* Special handling for devices with capture quirks */
        p = find_implicit_fb_entry(chip, capture_implicit_fb_quirks, alts);
        if (p) {
                switch (p->type) {
                case IMPLICIT_FB_FIXED:
                        return 0; /* no quirk */
                case IMPLICIT_FB_BOTH:
                        chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
                        return add_generic_implicit_fb(chip, fmt, alts);
                }
        }

        /* Generic UAC2 implicit feedback */
        if (attr == USB_ENDPOINT_SYNC_ASYNC &&
            alts->desc.bInterfaceClass == USB_CLASS_AUDIO &&
            alts->desc.bInterfaceProtocol == UAC_VERSION_2 &&
            alts->desc.bNumEndpoints == 1) {
                if (add_generic_uac2_implicit_fb(chip, fmt,
                                                 alts->desc.bInterfaceNumber + 1,
                                                 alts->desc.bAlternateSetting))
                        return 1;
        }

        /* Roland/BOSS implicit feedback with vendor spec class */
        if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
                if (add_roland_implicit_fb(chip, fmt, alts) > 0)
                        return 1;
        }

        /* Pioneer devices with vendor spec class */
        if (is_pioneer_implicit_fb(chip, alts)) {
                chip->quirk_flags |= QUIRK_FLAG_PLAYBACK_FIRST;
                return add_implicit_fb_sync_ep(chip, fmt,
                                               get_endpoint(alts, 1)->bEndpointAddress,
                                               1, alts->desc.bInterfaceNumber,
                                               alts);
        }

        /* Try the generic implicit fb if available */
        if (chip->generic_implicit_fb ||
            (chip->quirk_flags & QUIRK_FLAG_GENERIC_IMPLICIT_FB))
                return add_generic_implicit_fb(chip, fmt, alts);

        /* No quirk */
        return 0;
}

/* same for capture, but only handling FIXED entry */
static int audioformat_capture_quirk(struct snd_usb_audio *chip,
                                     struct audioformat *fmt,
                                     struct usb_host_interface *alts)
{
        const struct snd_usb_implicit_fb_match *p;

        p = find_implicit_fb_entry(chip, capture_implicit_fb_quirks, alts);
        if (p && (p->type == IMPLICIT_FB_FIXED || p->type == IMPLICIT_FB_BOTH))
                return add_implicit_fb_sync_ep(chip, fmt, p->ep_num, 0,
                                               p->iface, NULL);

        /* Roland/BOSS need full-duplex streams */
        if (USB_ID_VENDOR(chip->usb_id) == 0x0582) {
                if (add_roland_capture_quirk(chip, fmt, alts) > 0)
                        return 1;
        }

        if (is_pioneer_implicit_fb(chip, alts))
                return 1; /* skip the quirk, also don't handle generic sync EP */
        return 0;
}

/*
 * Parse altset and set up implicit feedback endpoint on the audioformat
 */
int snd_usb_parse_implicit_fb_quirk(struct snd_usb_audio *chip,
                                    struct audioformat *fmt,
                                    struct usb_host_interface *alts)
{
        if (chip->quirk_flags & QUIRK_FLAG_SKIP_IMPLICIT_FB)
                return 0;
        if (fmt->endpoint & USB_DIR_IN)
                return audioformat_capture_quirk(chip, fmt, alts);
        else
                return audioformat_implicit_fb_quirk(chip, fmt, alts);
}

/*
 * Return the score of matching two audioformats.
 * Veto the audioformat if:
 * - It has no channels for some reason.
 * - Requested PCM format is not supported.
 * - Requested sample rate is not supported.
 */
static int match_endpoint_audioformats(struct snd_usb_substream *subs,
                                       const struct audioformat *fp,
                                       int rate, int channels,
                                       snd_pcm_format_t pcm_format)
{
        int i, score;

        if (fp->channels < 1)
                return 0;

        if (!(fp->formats & pcm_format_to_bits(pcm_format)))
                return 0;

        if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
                if (rate < fp->rate_min || rate > fp->rate_max)
                        return 0;
        } else {
                for (i = 0; i < fp->nr_rates; i++) {
                        if (fp->rate_table[i] == rate)
                                break;
                }
                if (i >= fp->nr_rates)
                        return 0;
        }

        score = 1;
        if (fp->channels == channels)
                score++;

        return score;
}

static struct snd_usb_substream *
find_matching_substream(struct snd_usb_audio *chip, int stream, int ep_num,
                        int fmt_type)
{
        struct snd_usb_stream *as;
        struct snd_usb_substream *subs;

        list_for_each_entry(as, &chip->pcm_list, list) {
                subs = &as->substream[stream];
                if (as->fmt_type == fmt_type && subs->ep_num == ep_num)
                        return subs;
        }

        return NULL;
}

/*
 * Return the audioformat that is suitable for the implicit fb
 */
const struct audioformat *
snd_usb_find_implicit_fb_sync_format(struct snd_usb_audio *chip,
                                     const struct audioformat *target,
                                     const struct snd_pcm_hw_params *params,
                                     int stream,
                                     bool *fixed_rate)
{
        struct snd_usb_substream *subs;
        const struct audioformat *fp, *sync_fmt = NULL;
        int score, high_score;

        /* Use the original audioformat as fallback for the shared altset */
        if (target->iface == target->sync_iface &&
            target->altsetting == target->sync_altsetting)
                sync_fmt = target;

        subs = find_matching_substream(chip, stream, target->sync_ep,
                                       target->fmt_type);
        if (!subs)
                goto end;

        high_score = 0;
        list_for_each_entry(fp, &subs->fmt_list, list) {
                score = match_endpoint_audioformats(subs, fp,
                                                    params_rate(params),
                                                    params_channels(params),
                                                    params_format(params));
                if (score > high_score) {
                        sync_fmt = fp;
                        high_score = score;
                }
        }

 end:
        if (fixed_rate)
                *fixed_rate = snd_usb_pcm_has_fixed_rate(subs);
        return sync_fmt;
}