root/sound/firewire/fireface/ff-pcm.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ff-pcm.c - a part of driver for RME Fireface series
 *
 * Copyright (c) 2015-2017 Takashi Sakamoto
 */

#include "ff.h"

static int hw_rule_rate(struct snd_pcm_hw_params *params,
                        struct snd_pcm_hw_rule *rule)
{
        const unsigned int *pcm_channels = 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 < ARRAY_SIZE(amdtp_rate_table); i++) {
                enum snd_ff_stream_mode mode;
                int err;

                err = snd_ff_stream_get_multiplier_mode(i, &mode);
                if (err < 0)
                        continue;

                if (!snd_interval_test(c, pcm_channels[mode]))
                        continue;

                t.min = min(t.min, amdtp_rate_table[i]);
                t.max = max(t.max, amdtp_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)
{
        const unsigned int *pcm_channels = 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 < ARRAY_SIZE(amdtp_rate_table); i++) {
                enum snd_ff_stream_mode mode;
                int err;

                err = snd_ff_stream_get_multiplier_mode(i, &mode);
                if (err < 0)
                        continue;

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

                t.min = min(t.min, pcm_channels[mode]);
                t.max = max(t.max, pcm_channels[mode]);
        }

        return snd_interval_refine(c, &t);
}

static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
                                     const unsigned int *pcm_channels)
{
        unsigned int rate, channels;
        int i;

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

        for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
                enum snd_ff_stream_mode mode;
                int err;

                err = snd_ff_stream_get_multiplier_mode(i, &mode);
                if (err < 0)
                        continue;

                channels = pcm_channels[mode];
                if (pcm_channels[mode] == 0)
                        continue;
                hw->channels_min = min(hw->channels_min, channels);
                hw->channels_max = max(hw->channels_max, channels);

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

static int pcm_init_hw_params(struct snd_ff *ff,
                              struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct amdtp_stream *s;
        const unsigned int *pcm_channels;
        int err;

        if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
                runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
                s = &ff->tx_stream;
                pcm_channels = ff->spec->pcm_capture_channels;
        } else {
                runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
                s = &ff->rx_stream;
                pcm_channels = ff->spec->pcm_playback_channels;
        }

        limit_channels_and_rates(&runtime->hw, pcm_channels);

        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
                                  hw_rule_channels, (void *)pcm_channels,
                                  SNDRV_PCM_HW_PARAM_RATE, -1);
        if (err < 0)
                return err;

        err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
                                  hw_rule_rate, (void *)pcm_channels,
                                  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
        if (err < 0)
                return err;

        return amdtp_ff_add_pcm_hw_constraints(s, runtime);
}

static int pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_ff *ff = substream->private_data;
        struct amdtp_domain *d = &ff->domain;
        unsigned int rate;
        enum snd_ff_clock_src src;
        int i, err;

        err = snd_ff_stream_lock_try(ff);
        if (err < 0)
                return err;

        err = pcm_init_hw_params(ff, substream);
        if (err < 0)
                goto release_lock;

        err = ff->spec->protocol->get_clock(ff, &rate, &src);
        if (err < 0)
                goto release_lock;

        scoped_guard(mutex, &ff->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_FF_CLOCK_SRC_INTERNAL) {
                        for (i = 0; i < CIP_SFC_COUNT; ++i) {
                                if (amdtp_rate_table[i] == rate)
                                        break;
                        }

                        // The unit is configured at sampling frequency which packet
                        // streaming engine can't support.
                        if (i >= CIP_SFC_COUNT) {
                                err = -EIO;
                                goto release_lock;
                        }

                        substream->runtime->hw.rate_min = rate;
                        substream->runtime->hw.rate_max = rate;
                } else {
                        if (ff->substreams_counter > 0) {
                                unsigned int frames_per_period = d->events_per_period;
                                unsigned int frames_per_buffer = d->events_per_buffer;

                                rate = amdtp_rate_table[ff->rx_stream.sfc];
                                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 release_lock;

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

        snd_pcm_set_sync(substream);

        return 0;

release_lock:
        snd_ff_stream_lock_release(ff);
        return err;
}

static int pcm_close(struct snd_pcm_substream *substream)
{
        struct snd_ff *ff = substream->private_data;

        snd_ff_stream_lock_release(ff);

        return 0;
}

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

        return err;
}

static int pcm_hw_free(struct snd_pcm_substream *substream)
{
        struct snd_ff *ff = substream->private_data;

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

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

        snd_ff_stream_stop_duplex(ff);

        return 0;
}

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

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

        err = snd_ff_stream_start_duplex(ff, runtime->rate);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&ff->tx_stream);

        return err;
}

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

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

        err = snd_ff_stream_start_duplex(ff, runtime->rate);
        if (err >= 0)
                amdtp_stream_pcm_prepare(&ff->rx_stream);

        return err;
}

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

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

        return 0;
}

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

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

        return 0;
}

static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_ff *ff = sbstrm->private_data;

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

static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
{
        struct snd_ff *ff = sbstrm->private_data;

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

static int pcm_capture_ack(struct snd_pcm_substream *substream)
{
        struct snd_ff *ff = substream->private_data;

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

static int pcm_playback_ack(struct snd_pcm_substream *substream)
{
        struct snd_ff *ff = substream->private_data;

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

int snd_ff_create_pcm_devices(struct snd_ff *ff)
{
        static const struct snd_pcm_ops pcm_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 pcm_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(ff->card, ff->card->driver, 0, 1, 1, &pcm);
        if (err < 0)
                return err;

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

        return 0;
}