root/sound/firewire/tascam/tascam-pcm.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * tascam-pcm.c - a part of driver for TASCAM FireWire series
 *
 * Copyright (c) 2015 Takashi Sakamoto
 */

#include "tascam.h"

static int pcm_init_hw_params(struct snd_tscm *tscm,
                              struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct amdtp_stream *stream;
        unsigned int pcm_channels;

        if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
                runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
                stream = &tscm->tx_stream;
                pcm_channels = tscm->spec->pcm_capture_analog_channels;
        } else {
                runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
                stream = &tscm->rx_stream;
                pcm_channels = tscm->spec->pcm_playback_analog_channels;
        }

        if (tscm->spec->has_adat)
                pcm_channels += 8;
        if (tscm->spec->has_spdif)
                pcm_channels += 2;
        runtime->hw.channels_min = runtime->hw.channels_max = pcm_channels;

        hw->rates = SNDRV_PCM_RATE_44100 |
                    SNDRV_PCM_RATE_48000 |
                    SNDRV_PCM_RATE_88200 |
                    SNDRV_PCM_RATE_96000;
        snd_pcm_limit_hw_rates(runtime);

        return amdtp_tscm_add_pcm_hw_constraints(stream, runtime);
}

static int pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;
        struct amdtp_domain *d = &tscm->domain;
        enum snd_tscm_clock clock;
        int err;

        err = snd_tscm_stream_lock_try(tscm);
        if (err < 0)
                return err;

        err = pcm_init_hw_params(tscm, substream);
        if (err < 0)
                goto err_locked;

        err = snd_tscm_stream_get_clock(tscm, &clock);
        if (err < 0)
                goto err_locked;

        scoped_guard(mutex, &tscm->mutex) {
                // When source of clock is not internal or any stream is reserved for
                // transmission of PCM frames, the available sampling rate is limited
                // at current one.
                if (clock != SND_TSCM_CLOCK_INTERNAL || tscm->substreams_counter > 0) {
                        unsigned int frames_per_period = d->events_per_period;
                        unsigned int frames_per_buffer = d->events_per_buffer;
                        unsigned int rate;

                        err = snd_tscm_stream_get_rate(tscm, &rate);
                        if (err < 0)
                                goto err_locked;
                        substream->runtime->hw.rate_min = rate;
                        substream->runtime->hw.rate_max = rate;

                        err = snd_pcm_hw_constraint_minmax(substream->runtime,
                                                           SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
                                                           frames_per_period, frames_per_period);
                        if (err < 0)
                                goto err_locked;

                        err = snd_pcm_hw_constraint_minmax(substream->runtime,
                                                           SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
                                                           frames_per_buffer, frames_per_buffer);
                        if (err < 0)
                                goto err_locked;
                }
        }

        snd_pcm_set_sync(substream);

        return 0;
err_locked:
        snd_tscm_stream_lock_release(tscm);
        return err;
}

static int pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;

        snd_tscm_stream_lock_release(tscm);

        return 0;
}

static int pcm_hw_params(struct snd_pcm_substream *substream,
                         struct snd_pcm_hw_params *hw_params)
{
        struct snd_tscm *tscm = substream->private_data;
        int err = 0;

        if (substream->runtime->state == SNDRV_PCM_STATE_OPEN) {
                unsigned int rate = params_rate(hw_params);
                unsigned int frames_per_period = params_period_size(hw_params);
                unsigned int frames_per_buffer = params_buffer_size(hw_params);

                guard(mutex)(&tscm->mutex);
                err = snd_tscm_stream_reserve_duplex(tscm, rate,
                                        frames_per_period, frames_per_buffer);
                if (err >= 0)
                        ++tscm->substreams_counter;
        }

        return err;
}

static int pcm_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;

        guard(mutex)(&tscm->mutex);

        if (substream->runtime->state != SNDRV_PCM_STATE_OPEN)
                --tscm->substreams_counter;

        snd_tscm_stream_stop_duplex(tscm);

        return 0;
}

static int pcm_capture_prepare(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        int err;

        guard(mutex)(&tscm->mutex);

        err = snd_tscm_stream_start_duplex(tscm, runtime->rate);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&tscm->tx_stream);

        return err;
}

static int pcm_playback_prepare(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;
        struct snd_pcm_runtime *runtime = substream->runtime;
        int err;

        guard(mutex)(&tscm->mutex);

        err = snd_tscm_stream_start_duplex(tscm, runtime->rate);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&tscm->rx_stream);

        return err;
}

static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_tscm *tscm = substream->private_data;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                amdtp_stream_pcm_trigger(&tscm->tx_stream, substream);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
                amdtp_stream_pcm_trigger(&tscm->tx_stream, NULL);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_tscm *tscm = substream->private_data;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                amdtp_stream_pcm_trigger(&tscm->rx_stream, substream);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
                amdtp_stream_pcm_trigger(&tscm->rx_stream, NULL);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_tscm *tscm = sbstrm->private_data;

        return amdtp_domain_stream_pcm_pointer(&tscm->domain, &tscm->tx_stream);
}

static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_tscm *tscm = sbstrm->private_data;

        return amdtp_domain_stream_pcm_pointer(&tscm->domain, &tscm->rx_stream);
}

static int pcm_capture_ack(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;

        return amdtp_domain_stream_pcm_ack(&tscm->domain, &tscm->tx_stream);
}

static int pcm_playback_ack(struct snd_pcm_substream *substream)
{
        struct snd_tscm *tscm = substream->private_data;

        return amdtp_domain_stream_pcm_ack(&tscm->domain, &tscm->rx_stream);
}

int snd_tscm_create_pcm_devices(struct snd_tscm *tscm)
{
        static const struct snd_pcm_ops capture_ops = {
                .open           = pcm_open,
                .close          = pcm_close,
                .hw_params      = pcm_hw_params,
                .hw_free        = pcm_hw_free,
                .prepare        = pcm_capture_prepare,
                .trigger        = pcm_capture_trigger,
                .pointer        = pcm_capture_pointer,
                .ack            = pcm_capture_ack,
        };
        static const struct snd_pcm_ops playback_ops = {
                .open           = pcm_open,
                .close          = pcm_close,
                .hw_params      = pcm_hw_params,
                .hw_free        = pcm_hw_free,
                .prepare        = pcm_playback_prepare,
                .trigger        = pcm_playback_trigger,
                .pointer        = pcm_playback_pointer,
                .ack            = pcm_playback_ack,
        };
        struct snd_pcm *pcm;
        int err;

        err = snd_pcm_new(tscm->card, tscm->card->driver, 0, 1, 1, &pcm);
        if (err < 0)
                return err;

        pcm->private_data = tscm;
        pcm->nonatomic = true;
        snprintf(pcm->name, sizeof(pcm->name),
                 "%s PCM", tscm->card->shortname);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);
        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &capture_ops);
        snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);

        return 0;
}