// SPDX-License-Identifier: GPL-2.0-only
/*
 * Line 6 Linux USB driver
 *
 * Copyright (C) 2004-2010 Markus Grabner (line6@grabner-graz.at)
 */

#include <linux/slab.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>

#include "capture.h"
#include "driver.h"
#include "playback.h"

/* impulse response volume controls */
static int snd_line6_impulse_volume_info(struct snd_kcontrol *kcontrol,
                                         struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 1;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 255;
        return 0;
}

static int snd_line6_impulse_volume_get(struct snd_kcontrol *kcontrol,
                                        struct snd_ctl_elem_value *ucontrol)
{
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);

        ucontrol->value.integer.value[0] = line6pcm->impulse_volume;
        return 0;
}

static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
                                        struct snd_ctl_elem_value *ucontrol)
{
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
        int value = ucontrol->value.integer.value[0];
        int err;

        if (line6pcm->impulse_volume == value)
                return 0;

        line6pcm->impulse_volume = value;
        if (value > 0) {
                err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
                if (err < 0) {
                        line6pcm->impulse_volume = 0;
                        return err;
                }
        } else {
                line6_pcm_release(line6pcm, LINE6_STREAM_IMPULSE);
        }
        return 1;
}

/* impulse response period controls */
static int snd_line6_impulse_period_info(struct snd_kcontrol *kcontrol,
                                         struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 1;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 2000;
        return 0;
}

static int snd_line6_impulse_period_get(struct snd_kcontrol *kcontrol,
                                        struct snd_ctl_elem_value *ucontrol)
{
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);

        ucontrol->value.integer.value[0] = line6pcm->impulse_period;
        return 0;
}

static int snd_line6_impulse_period_put(struct snd_kcontrol *kcontrol,
                                        struct snd_ctl_elem_value *ucontrol)
{
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
        int value = ucontrol->value.integer.value[0];

        if (line6pcm->impulse_period == value)
                return 0;

        line6pcm->impulse_period = value;
        return 1;
}

/*
        Unlink all currently active URBs.
*/
static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
                                    struct line6_pcm_stream *pcms)
{
        int i;

        for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
                if (test_bit(i, &pcms->active_urbs)) {
                        if (!test_and_set_bit(i, &pcms->unlink_urbs))
                                usb_unlink_urb(pcms->urbs[i]);
                }
        }
}

/*
        Wait until unlinking of all currently active URBs has been finished.
*/
static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
                                        struct line6_pcm_stream *pcms)
{
        int timeout = HZ;
        int i;
        int alive;

        do {
                alive = 0;
                for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
                        if (test_bit(i, &pcms->active_urbs))
                                alive++;
                }
                if (!alive)
                        break;
                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(1);
        } while (--timeout > 0);
        if (alive)
                dev_err(line6pcm->line6->ifcdev,
                        "timeout: still %d active urbs..\n", alive);
}

static inline struct line6_pcm_stream *
get_stream(struct snd_line6_pcm *line6pcm, int direction)
{
        return (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
                &line6pcm->out : &line6pcm->in;
}

/* allocate a buffer if not opened yet;
 * call this in line6pcm.state_mutex
 */
static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
                                struct line6_pcm_stream *pstr, int direction, int type)
{
        const int pkt_size =
                (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
                        line6pcm->max_packet_size_out :
                        line6pcm->max_packet_size_in;

        /* Invoked multiple times in a row so allocate once only */
        if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
                pstr->buffer =
                        kmalloc(array3_size(line6pcm->line6->iso_buffers,
                                            LINE6_ISO_PACKETS, pkt_size),
                                GFP_KERNEL);
                if (!pstr->buffer)
                        return -ENOMEM;
        }
        return 0;
}

/* free a buffer if all streams are closed;
 * call this in line6pcm.state_mutex
 */
static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
                                 struct line6_pcm_stream *pstr, int type)
{
        clear_bit(type, &pstr->opened);
        if (!pstr->opened) {
                line6_wait_clear_audio_urbs(line6pcm, pstr);
                kfree(pstr->buffer);
                pstr->buffer = NULL;
        }
}

/* start a PCM stream */
static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
                              int type)
{
        struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
        int ret = 0;

        guard(spinlock_irqsave)(&pstr->lock);
        if (!test_and_set_bit(type, &pstr->running) &&
            !(pstr->active_urbs || pstr->unlink_urbs)) {
                pstr->count = 0;
                /* Submit all currently available URBs */
                if (direction == SNDRV_PCM_STREAM_PLAYBACK)
                        ret = line6_submit_audio_out_all_urbs(line6pcm);
                else
                        ret = line6_submit_audio_in_all_urbs(line6pcm);
        }

        if (ret < 0)
                clear_bit(type, &pstr->running);
        return ret;
}

/* stop a PCM stream; this doesn't sync with the unlinked URBs */
static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
                          int type)
{
        struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);

        scoped_guard(spinlock_irqsave, &pstr->lock) {
                clear_bit(type, &pstr->running);
                if (pstr->running)
                        return;
        }

        line6_unlink_audio_urbs(line6pcm, pstr);
        if (direction == SNDRV_PCM_STREAM_CAPTURE) {
                guard(spinlock_irqsave)(&pstr->lock);
                line6pcm->prev_fbuf = NULL;
                line6pcm->prev_fsize = 0;
        }
}

/* common PCM trigger callback */
int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
        struct snd_pcm_substream *s;
        int err;

        clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);

        snd_pcm_group_for_each_entry(s, substream) {
                if (s->pcm->card != substream->pcm->card)
                        continue;

                switch (cmd) {
                case SNDRV_PCM_TRIGGER_START:
                case SNDRV_PCM_TRIGGER_RESUME:
                        if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
                                (line6pcm->line6->properties->capabilities &
                                        LINE6_CAP_IN_NEEDS_OUT)) {
                                err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
                                                 LINE6_STREAM_CAPTURE_HELPER);
                                if (err < 0)
                                        return err;
                        }
                        err = line6_stream_start(line6pcm, s->stream,
                                                 LINE6_STREAM_PCM);
                        if (err < 0)
                                return err;
                        break;

                case SNDRV_PCM_TRIGGER_STOP:
                case SNDRV_PCM_TRIGGER_SUSPEND:
                        if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
                                (line6pcm->line6->properties->capabilities &
                                        LINE6_CAP_IN_NEEDS_OUT)) {
                                line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
                                          LINE6_STREAM_CAPTURE_HELPER);
                        }
                        line6_stream_stop(line6pcm, s->stream,
                                          LINE6_STREAM_PCM);
                        break;

                case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                        if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
                                return -EINVAL;
                        set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
                        break;

                case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                        if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
                                return -EINVAL;
                        clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
                        break;

                default:
                        return -EINVAL;
                }
        }

        return 0;
}

/* common PCM pointer callback */
snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
{
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
        struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);

        return pstr->pos_done;
}

/* Stop and release duplex streams */
static void __line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
{
        struct line6_pcm_stream *pstr;
        int dir;

        for (dir = 0; dir < 2; dir++)
                line6_stream_stop(line6pcm, dir, type);
        for (dir = 0; dir < 2; dir++) {
                pstr = get_stream(line6pcm, dir);
                line6_buffer_release(line6pcm, pstr, type);
        }
}

/* Stop and release duplex streams */
void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
{
        guard(mutex)(&line6pcm->state_mutex);
        __line6_pcm_release(line6pcm, type);
}
EXPORT_SYMBOL_GPL(line6_pcm_release);

/* Acquire and optionally start duplex streams:
 * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
 */
int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
{
        struct line6_pcm_stream *pstr;
        int ret = 0, dir;

        /* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
        guard(mutex)(&line6pcm->state_mutex);
        for (dir = 0; dir < 2; dir++) {
                pstr = get_stream(line6pcm, dir);
                ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
                if (ret < 0)
                        goto error;
                if (!pstr->running)
                        line6_wait_clear_audio_urbs(line6pcm, pstr);
        }
        if (start) {
                for (dir = 0; dir < 2; dir++) {
                        ret = line6_stream_start(line6pcm, dir, type);
                        if (ret < 0)
                                goto error;
                }
        }
 error:
        if (ret < 0)
                __line6_pcm_release(line6pcm, type);
        return ret;
}
EXPORT_SYMBOL_GPL(line6_pcm_acquire);

/* common PCM hw_params callback */
int snd_line6_hw_params(struct snd_pcm_substream *substream,
                        struct snd_pcm_hw_params *hw_params)
{
        int ret;
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
        struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);

        guard(mutex)(&line6pcm->state_mutex);
        ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
                                   LINE6_STREAM_PCM);
        if (ret < 0)
                return ret;

        pstr->period = params_period_bytes(hw_params);
        return 0;
}

/* common PCM hw_free callback */
int snd_line6_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
        struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);

        guard(mutex)(&line6pcm->state_mutex);
        line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
        return 0;
}


/* control info callback */
static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
                                           struct snd_ctl_elem_info *uinfo)
{
        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
        uinfo->count = 2;
        uinfo->value.integer.min = 0;
        uinfo->value.integer.max = 256;
        return 0;
}

/* control get callback */
static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
                                          struct snd_ctl_elem_value *ucontrol)
{
        int i;
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);

        for (i = 0; i < 2; i++)
                ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];

        return 0;
}

/* control put callback */
static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
                                          struct snd_ctl_elem_value *ucontrol)
{
        int i, changed = 0;
        struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);

        for (i = 0; i < 2; i++)
                if (line6pcm->volume_playback[i] !=
                    ucontrol->value.integer.value[i]) {
                        line6pcm->volume_playback[i] =
                            ucontrol->value.integer.value[i];
                        changed = 1;
                }

        return changed;
}

/* control definition */
static const struct snd_kcontrol_new line6_controls[] = {
        {
                .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
                .name = "PCM Playback Volume",
                .info = snd_line6_control_playback_info,
                .get = snd_line6_control_playback_get,
                .put = snd_line6_control_playback_put
        },
        {
                .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
                .name = "Impulse Response Volume",
                .info = snd_line6_impulse_volume_info,
                .get = snd_line6_impulse_volume_get,
                .put = snd_line6_impulse_volume_put
        },
        {
                .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
                .name = "Impulse Response Period",
                .info = snd_line6_impulse_period_info,
                .get = snd_line6_impulse_period_get,
                .put = snd_line6_impulse_period_put
        },
};

/*
        Cleanup the PCM device.
*/
static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
{
        int i;

        /* Most likely impossible in current code... */
        if (pcms->urbs == NULL)
                return;

        for (i = 0; i < iso_buffers; i++) {
                if (pcms->urbs[i]) {
                        usb_kill_urb(pcms->urbs[i]);
                        usb_free_urb(pcms->urbs[i]);
                }
        }
        kfree(pcms->urbs);
        pcms->urbs = NULL;
}

static void line6_cleanup_pcm(struct snd_pcm *pcm)
{
        struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);

        cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
        cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
        kfree(line6pcm);
}

/* create a PCM device */
static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
{
        struct snd_pcm *pcm;
        int err;

        err = snd_pcm_new(line6->card, (char *)line6->properties->name,
                          0, 1, 1, pcm_ret);
        if (err < 0)
                return err;
        pcm = *pcm_ret;
        strscpy(pcm->name, line6->properties->name);

        /* set operators */
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
                        &snd_line6_playback_ops);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);

        /* pre-allocation of buffers */
        snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
                                       NULL, 64 * 1024, 128 * 1024);
        return 0;
}

/*
        Sync with PCM stream stops.
*/
void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
{
        line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
        line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
        line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
        line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
}

/*
        Create and register the PCM device and mixer entries.
        Create URBs for playback and capture.
*/
int line6_init_pcm(struct usb_line6 *line6,
                   struct line6_pcm_properties *properties)
{
        int i, err;
        unsigned ep_read = line6->properties->ep_audio_r;
        unsigned ep_write = line6->properties->ep_audio_w;
        struct snd_pcm *pcm;
        struct snd_line6_pcm *line6pcm;

        if (!(line6->properties->capabilities & LINE6_CAP_PCM))
                return 0;       /* skip PCM initialization and report success */

        err = snd_line6_new_pcm(line6, &pcm);
        if (err < 0)
                return err;

        line6pcm = kzalloc_obj(*line6pcm);
        if (!line6pcm)
                return -ENOMEM;

        mutex_init(&line6pcm->state_mutex);
        line6pcm->pcm = pcm;
        line6pcm->properties = properties;
        line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
        line6pcm->volume_monitor = 255;
        line6pcm->line6 = line6;

        spin_lock_init(&line6pcm->out.lock);
        spin_lock_init(&line6pcm->in.lock);
        line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;

        line6->line6pcm = line6pcm;

        pcm->private_data = line6pcm;
        pcm->private_free = line6_cleanup_pcm;

        line6pcm->max_packet_size_in =
                usb_maxpacket(line6->usbdev,
                        usb_rcvisocpipe(line6->usbdev, ep_read));
        line6pcm->max_packet_size_out =
                usb_maxpacket(line6->usbdev,
                        usb_sndisocpipe(line6->usbdev, ep_write));
        if (!line6pcm->max_packet_size_in || !line6pcm->max_packet_size_out) {
                dev_err(line6pcm->line6->ifcdev,
                        "cannot get proper max packet size\n");
                return -EINVAL;
        }

        err = line6_create_audio_out_urbs(line6pcm);
        if (err < 0)
                return err;

        err = line6_create_audio_in_urbs(line6pcm);
        if (err < 0)
                return err;

        /* mixer: */
        for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
                err = snd_ctl_add(line6->card,
                                  snd_ctl_new1(&line6_controls[i], line6pcm));
                if (err < 0)
                        return err;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(line6_init_pcm);

/* prepare pcm callback */
int snd_line6_prepare(struct snd_pcm_substream *substream)
{
        struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
        struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);

        guard(mutex)(&line6pcm->state_mutex);
        if (!pstr->running)
                line6_wait_clear_audio_urbs(line6pcm, pstr);

        if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
                line6pcm->out.count = 0;
                line6pcm->out.pos = 0;
                line6pcm->out.pos_done = 0;
                line6pcm->out.bytes = 0;
                line6pcm->in.count = 0;
                line6pcm->in.pos_done = 0;
                line6pcm->in.bytes = 0;
        }

        return 0;
}