root/sound/firewire/bebob/bebob_pcm.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * bebob_pcm.c - a part of driver for BeBoB based devices
 *
 * Copyright (c) 2013-2014 Takashi Sakamoto
 */

#include "./bebob.h"

static int
hw_rule_rate(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
{
        struct snd_bebob_stream_formation *formations = rule->private;
        struct snd_interval *r =
                hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
        const struct snd_interval *c =
                hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
        struct snd_interval t = {
                .min = UINT_MAX, .max = 0, .integer = 1
        };
        unsigned int i;

        for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
                /* entry is invalid */
                if (formations[i].pcm == 0)
                        continue;

                if (!snd_interval_test(c, formations[i].pcm))
                        continue;

                t.min = min(t.min, snd_bebob_rate_table[i]);
                t.max = max(t.max, snd_bebob_rate_table[i]);

        }
        return snd_interval_refine(r, &t);
}

static int
hw_rule_channels(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
{
        struct snd_bebob_stream_formation *formations = rule->private;
        struct snd_interval *c =
                hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
        const struct snd_interval *r =
                hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
        struct snd_interval t = {
                .min = UINT_MAX, .max = 0, .integer = 1
        };

        unsigned int i;

        for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
                /* entry is invalid */
                if (formations[i].pcm == 0)
                        continue;

                if (!snd_interval_test(r, snd_bebob_rate_table[i]))
                        continue;

                t.min = min(t.min, formations[i].pcm);
                t.max = max(t.max, formations[i].pcm);
        }

        return snd_interval_refine(c, &t);
}

static void
limit_channels_and_rates(struct snd_pcm_hardware *hw,
                         struct snd_bebob_stream_formation *formations)
{
        unsigned int i;

        hw->channels_min = UINT_MAX;
        hw->channels_max = 0;

        hw->rate_min = UINT_MAX;
        hw->rate_max = 0;
        hw->rates = 0;

        for (i = 0; i < SND_BEBOB_STRM_FMT_ENTRIES; i++) {
                /* entry has no PCM channels */
                if (formations[i].pcm == 0)
                        continue;

                hw->channels_min = min(hw->channels_min, formations[i].pcm);
                hw->channels_max = max(hw->channels_max, formations[i].pcm);

                hw->rate_min = min(hw->rate_min, snd_bebob_rate_table[i]);
                hw->rate_max = max(hw->rate_max, snd_bebob_rate_table[i]);
                hw->rates |= snd_pcm_rate_to_rate_bit(snd_bebob_rate_table[i]);
        }
}

static int
pcm_init_hw_params(struct snd_bebob *bebob,
                   struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct amdtp_stream *s;
        struct snd_bebob_stream_formation *formations;
        int err;

        if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
                runtime->hw.formats = AM824_IN_PCM_FORMAT_BITS;
                s = &bebob->tx_stream;
                formations = bebob->tx_stream_formations;
        } else {
                runtime->hw.formats = AM824_OUT_PCM_FORMAT_BITS;
                s = &bebob->rx_stream;
                formations = bebob->rx_stream_formations;
        }

        limit_channels_and_rates(&runtime->hw, formations);

        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
                                  hw_rule_channels, formations,
                                  SNDRV_PCM_HW_PARAM_RATE, -1);
        if (err < 0)
                goto end;

        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                  hw_rule_rate, formations,
                                  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
        if (err < 0)
                goto end;

        err = amdtp_am824_add_pcm_hw_constraints(s, runtime);
end:
        return err;
}

static int pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;
        const struct snd_bebob_rate_spec *spec = bebob->spec->rate;
        struct amdtp_domain *d = &bebob->domain;
        enum snd_bebob_clock_type src;
        int err;

        err = snd_bebob_stream_lock_try(bebob);
        if (err < 0)
                return err;

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

        err = snd_bebob_stream_get_clock_src(bebob, &src);
        if (err < 0)
                goto err_locked;

        scoped_guard(mutex, &bebob->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 (src == SND_BEBOB_CLOCK_TYPE_EXTERNAL ||
                    (bebob->substreams_counter > 0 && d->events_per_period > 0)) {
                        unsigned int frames_per_period = d->events_per_period;
                        unsigned int frames_per_buffer = d->events_per_buffer;
                        unsigned int sampling_rate;

                        err = spec->get(bebob, &sampling_rate);
                        if (err < 0) {
                                dev_err(&bebob->unit->device,
                                        "fail to get sampling rate: %d\n", err);
                                goto err_locked;
                        }

                        substream->runtime->hw.rate_min = sampling_rate;
                        substream->runtime->hw.rate_max = sampling_rate;

                        if (frames_per_period > 0) {
                                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_bebob_stream_lock_release(bebob);
        return err;
}

static int
pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;
        snd_bebob_stream_lock_release(bebob);
        return 0;
}

static int pcm_hw_params(struct snd_pcm_substream *substream,
                         struct snd_pcm_hw_params *hw_params)
{
        struct snd_bebob *bebob = 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)(&bebob->mutex);
                err = snd_bebob_stream_reserve_duplex(bebob, rate,
                                        frames_per_period, frames_per_buffer);
                if (err >= 0)
                        ++bebob->substreams_counter;
        }

        return err;
}

static int pcm_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;

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

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

        snd_bebob_stream_stop_duplex(bebob);

        return 0;
}

static int
pcm_capture_prepare(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;
        int err;

        err = snd_bebob_stream_start_duplex(bebob);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&bebob->tx_stream);

        return err;
}
static int
pcm_playback_prepare(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;
        int err;

        err = snd_bebob_stream_start_duplex(bebob);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&bebob->rx_stream);

        return err;
}

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

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

        return 0;
}
static int
pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_bebob *bebob = substream->private_data;

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

        return 0;
}

static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_bebob *bebob = sbstrm->private_data;

        return amdtp_domain_stream_pcm_pointer(&bebob->domain,
                                               &bebob->tx_stream);
}
static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_bebob *bebob = sbstrm->private_data;

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

static int pcm_capture_ack(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;

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

static int pcm_playback_ack(struct snd_pcm_substream *substream)
{
        struct snd_bebob *bebob = substream->private_data;

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

int snd_bebob_create_pcm_devices(struct snd_bebob *bebob)
{
        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(bebob->card, bebob->card->driver, 0, 1, 1, &pcm);
        if (err < 0)
                goto end;

        pcm->private_data = bebob;
        pcm->nonatomic = true;
        snprintf(pcm->name, sizeof(pcm->name),
                 "%s PCM", bebob->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);
end:
        return err;
}