// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Clock domain and sample rate management functions
 */

#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/string.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/info.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "card.h"
#include "helper.h"
#include "clock.h"
#include "quirks.h"

union uac23_clock_source_desc {
        struct uac_clock_source_descriptor v2;
        struct uac3_clock_source_descriptor v3;
};

union uac23_clock_selector_desc {
        struct uac_clock_selector_descriptor v2;
        struct uac3_clock_selector_descriptor v3;
};

union uac23_clock_multiplier_desc {
        struct uac_clock_multiplier_descriptor v2;
        struct uac_clock_multiplier_descriptor v3;
};

#define GET_VAL(p, proto, field) \
        ((proto) == UAC_VERSION_3 ? (p)->v3.field : (p)->v2.field)

static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
                                 bool (*validator)(void *, int, int),
                                 u8 type, int proto)
{
        void *cs = NULL;

        while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
                                             cs, type))) {
                if (validator(cs, id, proto))
                        return cs;
        }

        return NULL;
}

static bool validate_clock_source(void *p, int id, int proto)
{
        union uac23_clock_source_desc *cs = p;

        return GET_VAL(cs, proto, bClockID) == id;
}

static bool validate_clock_selector(void *p, int id, int proto)
{
        union uac23_clock_selector_desc *cs = p;

        return GET_VAL(cs, proto, bClockID) == id;
}

static bool validate_clock_multiplier(void *p, int id, int proto)
{
        union uac23_clock_multiplier_desc *cs = p;

        return GET_VAL(cs, proto, bClockID) == id;
}

#define DEFINE_FIND_HELPER(name, obj, validator, type2, type3)          \
static obj *name(struct snd_usb_audio *chip, int id, int proto) \
{                                                                       \
        return find_uac_clock_desc(chip->ctrl_intf, id, validator,      \
                                   proto == UAC_VERSION_3 ? (type3) : (type2), \
                                   proto);                              \
}

DEFINE_FIND_HELPER(snd_usb_find_clock_source,
                   union uac23_clock_source_desc, validate_clock_source,
                   UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
                   union uac23_clock_selector_desc, validate_clock_selector,
                   UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
                   union uac23_clock_multiplier_desc, validate_clock_multiplier,
                   UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);

static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
{
        unsigned char buf;
        int ret;

        ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
                              UAC2_CS_CUR,
                              USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
                              UAC2_CX_CLOCK_SELECTOR << 8,
                              snd_usb_ctrl_intf(chip) | (selector_id << 8),
                              &buf, sizeof(buf));

        if (ret < 0)
                return ret;

        return buf;
}

static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
                                        unsigned char pin)
{
        int ret;

        ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
                              UAC2_CS_CUR,
                              USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
                              UAC2_CX_CLOCK_SELECTOR << 8,
                              snd_usb_ctrl_intf(chip) | (selector_id << 8),
                              &pin, sizeof(pin));
        if (ret < 0)
                return ret;

        if (ret != sizeof(pin)) {
                usb_audio_err(chip,
                        "setting selector (id %d) unexpected length %d\n",
                        selector_id, ret);
                return -EINVAL;
        }

        ret = uac_clock_selector_get_val(chip, selector_id);
        if (ret < 0)
                return ret;

        if (ret != pin) {
                usb_audio_err(chip,
                        "setting selector (id %d) to %x failed (current: %d)\n",
                        selector_id, pin, ret);
                return -EINVAL;
        }

        return ret;
}

static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
                                            const struct audioformat *fmt,
                                            int source_id)
{
        bool ret = false;
        int count;
        unsigned char data;
        struct usb_device *dev = chip->dev;
        union uac23_clock_source_desc *cs_desc;

        cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
        if (!cs_desc)
                return false;

        if (fmt->protocol == UAC_VERSION_2) {
                /*
                 * Assume the clock is valid if clock source supports only one
                 * single sample rate, the terminal is connected directly to it
                 * (there is no clock selector) and clock type is internal.
                 * This is to deal with some Denon DJ controllers that always
                 * reports that clock is invalid.
                 */
                if (fmt->nr_rates == 1 &&
                    (fmt->clock & 0xff) == cs_desc->v2.bClockID &&
                    (cs_desc->v2.bmAttributes & 0x3) !=
                                UAC_CLOCK_SOURCE_TYPE_EXT)
                        return true;
        }

        /*
         * MOTU MicroBook IIc
         * Sample rate changes takes more than 2 seconds for this device. Clock
         * validity request returns false during that period.
         */
        if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
                count = 0;

                while ((!ret) && (count < 50)) {
                        int err;

                        msleep(100);

                        err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
                                              USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
                                              UAC2_CS_CONTROL_CLOCK_VALID << 8,
                                              snd_usb_ctrl_intf(chip) | (source_id << 8),
                                              &data, sizeof(data));
                        if (err < 0) {
                                dev_warn(&dev->dev,
                                         "%s(): cannot get clock validity for id %d\n",
                                           __func__, source_id);
                                return false;
                        }

                        ret = !!data;
                        count++;
                }
        }

        return ret;
}

static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
                                      const struct audioformat *fmt,
                                      int source_id)
{
        int err;
        unsigned char data;
        struct usb_device *dev = chip->dev;
        u32 bmControls;
        union uac23_clock_source_desc *cs_desc;

        cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
        if (!cs_desc)
                return false;

        if (fmt->protocol == UAC_VERSION_3)
                bmControls = le32_to_cpu(cs_desc->v3.bmControls);
        else
                bmControls = cs_desc->v2.bmControls;

        /* If a clock source can't tell us whether it's valid, we assume it is */
        if (!uac_v2v3_control_is_readable(bmControls,
                                      UAC2_CS_CONTROL_CLOCK_VALID))
                return true;

        err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
                              USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
                              UAC2_CS_CONTROL_CLOCK_VALID << 8,
                              snd_usb_ctrl_intf(chip) | (source_id << 8),
                              &data, sizeof(data));

        if (err < 0) {
                dev_warn(&dev->dev,
                         "%s(): cannot get clock validity for id %d\n",
                           __func__, source_id);
                return false;
        }

        if (data)
                return true;
        else
                return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
}

static int __uac_clock_find_source(struct snd_usb_audio *chip,
                                   const struct audioformat *fmt, int entity_id,
                                   unsigned long *visited, bool validate)
{
        union uac23_clock_source_desc *source;
        union uac23_clock_selector_desc *selector;
        union uac23_clock_multiplier_desc *multiplier;
        int ret, i, cur, err, pins, clock_id;
        const u8 *sources;
        int proto = fmt->protocol;

        entity_id &= 0xff;

        if (test_and_set_bit(entity_id, visited)) {
                usb_audio_warn(chip,
                         "%s(): recursive clock topology detected, id %d.\n",
                         __func__, entity_id);
                return -EINVAL;
        }

        /* first, see if the ID we're looking for is a clock source already */
        source = snd_usb_find_clock_source(chip, entity_id, proto);
        if (source) {
                entity_id = GET_VAL(source, proto, bClockID);
                if (validate && !uac_clock_source_is_valid(chip, fmt,
                                                                entity_id)) {
                        usb_audio_err(chip,
                                "clock source %d is not valid, cannot use\n",
                                entity_id);
                        return -ENXIO;
                }
                return entity_id;
        }

        selector = snd_usb_find_clock_selector(chip, entity_id, proto);
        if (selector) {
                pins = GET_VAL(selector, proto, bNrInPins);
                clock_id = GET_VAL(selector, proto, bClockID);
                sources = GET_VAL(selector, proto, baCSourceID);
                cur = 0;

                if (pins == 1) {
                        ret = 1;
                        goto find_source;
                }

                /* the entity ID we are looking for is a selector.
                 * find out what it currently selects */
                ret = uac_clock_selector_get_val(chip, clock_id);
                if (ret < 0) {
                        if (!chip->autoclock)
                                return ret;
                        goto find_others;
                }

                /* Selector values are one-based */

                if (ret > pins || ret < 1) {
                        usb_audio_err(chip,
                                "%s(): selector reported illegal value, id %d, ret %d\n",
                                __func__, clock_id, ret);

                        if (!chip->autoclock)
                                return -EINVAL;
                        goto find_others;
                }

        find_source:
                cur = ret;
                ret = __uac_clock_find_source(chip, fmt,
                                              sources[ret - 1],
                                              visited, validate);
                if (ret > 0) {
                        /* Skip setting clock selector again for some devices */
                        if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR)
                                return ret;
                        err = uac_clock_selector_set_val(chip, entity_id, cur);
                        if (err < 0)
                                return err;
                }

                if (!validate || ret > 0 || !chip->autoclock)
                        return ret;

        find_others:
                /* The current clock source is invalid, try others. */
                for (i = 1; i <= pins; i++) {
                        if (i == cur)
                                continue;

                        ret = __uac_clock_find_source(chip, fmt,
                                                      sources[i - 1],
                                                      visited, true);
                        if (ret < 0)
                                continue;

                        err = uac_clock_selector_set_val(chip, entity_id, i);
                        if (err < 0)
                                continue;

                        usb_audio_info(chip,
                                 "found and selected valid clock source %d\n",
                                 ret);
                        return ret;
                }

                return -ENXIO;
        }

        /* FIXME: multipliers only act as pass-thru element for now */
        multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
        if (multiplier)
                return __uac_clock_find_source(chip, fmt,
                                               GET_VAL(multiplier, proto, bCSourceID),
                                               visited, validate);

        return -EINVAL;
}

/*
 * For all kinds of sample rate settings and other device queries,
 * the clock source (end-leaf) must be used. However, clock selectors,
 * clock multipliers and sample rate converters may be specified as
 * clock source input to terminal. This functions walks the clock path
 * to its end and tries to find the source.
 *
 * The 'visited' bitfield is used internally to detect recursive loops.
 *
 * Returns the clock source UnitID (>=0) on success, or an error.
 */
int snd_usb_clock_find_source(struct snd_usb_audio *chip,
                              const struct audioformat *fmt, bool validate)
{
        DECLARE_BITMAP(visited, 256);
        memset(visited, 0, sizeof(visited));

        switch (fmt->protocol) {
        case UAC_VERSION_2:
        case UAC_VERSION_3:
                return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
                                               validate);
        default:
                return -EINVAL;
        }
}

static int set_sample_rate_v1(struct snd_usb_audio *chip,
                              const struct audioformat *fmt, int rate)
{
        struct usb_device *dev = chip->dev;
        unsigned char data[3];
        int err, crate;

        /* if endpoint doesn't have sampling rate control, bail out */
        if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
                return 0;

        data[0] = rate;
        data[1] = rate >> 8;
        data[2] = rate >> 16;
        err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
                              USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
                              UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
                              fmt->endpoint, data, sizeof(data));
        if (err < 0) {
                dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
                        fmt->iface, fmt->altsetting, rate, fmt->endpoint);
                return err;
        }

        /* Don't check the sample rate for devices which we know don't
         * support reading */
        if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
                return 0;
        /* the firmware is likely buggy, don't repeat to fail too many times */
        if (chip->sample_rate_read_error > 2)
                return 0;

        err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
                              USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
                              UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
                              fmt->endpoint, data, sizeof(data));
        if (err < 0) {
                dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
                        fmt->iface, fmt->altsetting, fmt->endpoint);
                chip->sample_rate_read_error++;
                return 0; /* some devices don't support reading */
        }

        crate = data[0] | (data[1] << 8) | (data[2] << 16);
        if (!crate) {
                dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
                chip->sample_rate_read_error = 3; /* three strikes, see above */
                return 0;
        }

        if (crate != rate) {
                dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
                // runtime->rate = crate;
        }

        return 0;
}

static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
                              int altsetting, int clock)
{
        struct usb_device *dev = chip->dev;
        __le32 data;
        int err;

        err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
                              USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
                              UAC2_CS_CONTROL_SAM_FREQ << 8,
                              snd_usb_ctrl_intf(chip) | (clock << 8),
                              &data, sizeof(data));
        if (err < 0) {
                dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
                         iface, altsetting, err);
                return 0;
        }

        return le32_to_cpu(data);
}

/*
 * Try to set the given sample rate:
 *
 * Return 0 if the clock source is read-only, the actual rate on success,
 * or a negative error code.
 *
 * This function gets called from format.c to validate each sample rate, too.
 * Hence no message is shown upon error
 */
int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
                                 const struct audioformat *fmt,
                                 int clock, int rate)
{
        bool writeable;
        u32 bmControls;
        __le32 data;
        int err;
        union uac23_clock_source_desc *cs_desc;

        cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
        if (fmt->protocol == UAC_VERSION_3)
                bmControls = le32_to_cpu(cs_desc->v3.bmControls);
        else
                bmControls = cs_desc->v2.bmControls;

        writeable = uac_v2v3_control_is_writeable(bmControls,
                                                  UAC2_CS_CONTROL_SAM_FREQ);
        if (!writeable)
                return 0;

        data = cpu_to_le32(rate);
        err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
                              USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
                              UAC2_CS_CONTROL_SAM_FREQ << 8,
                              snd_usb_ctrl_intf(chip) | (clock << 8),
                              &data, sizeof(data));
        if (err < 0)
                return err;

        return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
}

static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
                                const struct audioformat *fmt, int rate)
{
        int cur_rate, prev_rate;
        int clock;

        /* First, try to find a valid clock. This may trigger
         * automatic clock selection if the current clock is not
         * valid.
         */
        clock = snd_usb_clock_find_source(chip, fmt, true);
        if (clock < 0) {
                /* We did not find a valid clock, but that might be
                 * because the current sample rate does not match an
                 * external clock source. Try again without validation
                 * and we will do another validation after setting the
                 * rate.
                 */
                clock = snd_usb_clock_find_source(chip, fmt, false);

                /* Hardcoded sample rates */
                if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
                        return 0;

                if (clock < 0)
                        return clock;
        }

        prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
        if (prev_rate == rate)
                goto validation;

        cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
        if (cur_rate < 0) {
                usb_audio_err(chip,
                              "%d:%d: cannot set freq %d (v2/v3): err %d\n",
                              fmt->iface, fmt->altsetting, rate, cur_rate);
                return cur_rate;
        }

        if (!cur_rate)
                cur_rate = prev_rate;

        if (cur_rate != rate) {
                usb_audio_dbg(chip,
                              "%d:%d: freq mismatch: req %d, clock runs @%d\n",
                              fmt->iface, fmt->altsetting, rate, cur_rate);
                /* continue processing */
        }

validation:
        /* validate clock after rate change */
        if (!uac_clock_source_is_valid(chip, fmt, clock))
                return -ENXIO;
        return 0;
}

int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
                             const struct audioformat *fmt, int rate)
{
        usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
                      fmt->iface, fmt->altsetting, rate, fmt->clock);

        switch (fmt->protocol) {
        case UAC_VERSION_1:
        default:
                return set_sample_rate_v1(chip, fmt, rate);

        case UAC_VERSION_3:
                if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
                        if (rate != UAC3_BADD_SAMPLING_RATE)
                                return -ENXIO;
                        else
                                return 0;
                }
                fallthrough;
        case UAC_VERSION_2:
                return set_sample_rate_v2v3(chip, fmt, rate);
        }
}