text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * digi00x-pcm.c - a part of driver for Digidesign Digi 002/003 family
   *
   * Copyright (c) 2014-2015 Takashi Sakamoto
   */
  
  #include "digi00x.h"
  
  static int hw_rule_rate(struct snd_pcm_hw_params *params,
  			struct snd_pcm_hw_rule *rule)
  {
  	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_DG00X_RATE_COUNT; i++) {
  		if (!snd_interval_test(c,
  				       snd_dg00x_stream_pcm_channels[i]))
  			continue;
  
  		t.min = min(t.min, snd_dg00x_stream_rates[i]);
  		t.max = max(t.max, snd_dg00x_stream_rates[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_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_DG00X_RATE_COUNT; i++) {
  		if (!snd_interval_test(r, snd_dg00x_stream_rates[i]))
  			continue;
  
  		t.min = min(t.min, snd_dg00x_stream_pcm_channels[i]);
  		t.max = max(t.max, snd_dg00x_stream_pcm_channels[i]);
  	}
  
  	return snd_interval_refine(c, &t);
  }
  
  static int pcm_init_hw_params(struct snd_dg00x *dg00x,
  			      struct snd_pcm_substream *substream)
  {
  	struct snd_pcm_runtime *runtime = substream->runtime;
  	struct snd_pcm_hardware *hw = &runtime->hw;
  	struct amdtp_stream *s;
  	int err;
  
  
  	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
  		substream->runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
  		s = &dg00x->tx_stream;
  	} else {
  		substream->runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
  		s = &dg00x->rx_stream;
  	}
  
  	hw->channels_min = 10;
  	hw->channels_max = 18;
  
  	hw->rates = SNDRV_PCM_RATE_44100 |
  		    SNDRV_PCM_RATE_48000 |
  		    SNDRV_PCM_RATE_88200 |
  		    SNDRV_PCM_RATE_96000;
  	snd_pcm_limit_hw_rates(runtime);
  
  	err = snd_pcm_hw_rule_add(substream->runtime, 0,
  				  SNDRV_PCM_HW_PARAM_CHANNELS,
  				  hw_rule_channels, NULL,
  				  SNDRV_PCM_HW_PARAM_RATE, -1);
  	if (err < 0)
  		return err;
  
  	err = snd_pcm_hw_rule_add(substream->runtime, 0,
  				  SNDRV_PCM_HW_PARAM_RATE,
  				  hw_rule_rate, NULL,
  				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
  	if (err < 0)
  		return err;
  
  	return amdtp_dot_add_pcm_hw_constraints(s, substream->runtime);
  }
  
  static int pcm_open(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  	struct amdtp_domain *d = &dg00x->domain;
  	enum snd_dg00x_clock clock;
  	bool detect;
  	int err;
  
  	err = snd_dg00x_stream_lock_try(dg00x);
  	if (err < 0)
  		return err;
  
  	err = pcm_init_hw_params(dg00x, substream);
  	if (err < 0)
  		goto err_locked;
  
  	/* Check current clock source. */
  	err = snd_dg00x_stream_get_clock(dg00x, &clock);
  	if (err < 0)
  		goto err_locked;
  	if (clock != SND_DG00X_CLOCK_INTERNAL) {
  		err = snd_dg00x_stream_check_external_clock(dg00x, &detect);
  		if (err < 0)
  			goto err_locked;
  		if (!detect) {
  			err = -EBUSY;
  			goto err_locked;
  		}
  	}
  
  	mutex_lock(&dg00x->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_DG00X_CLOCK_INTERNAL) ||
  	    (dg00x->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 rate;
  
  		err = snd_dg00x_stream_get_external_rate(dg00x, &rate);
  		if (err < 0) {
  			mutex_unlock(&dg00x->mutex);
  			goto err_locked;
  		}
  		substream->runtime->hw.rate_min = rate;
  		substream->runtime->hw.rate_max = 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) {
  				mutex_unlock(&dg00x->mutex);
  				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) {
  				mutex_unlock(&dg00x->mutex);
  				goto err_locked;
  			}
  		}
  	}
  
  	mutex_unlock(&dg00x->mutex);
  
  	snd_pcm_set_sync(substream);
  
  	return 0;
  err_locked:
  	snd_dg00x_stream_lock_release(dg00x);
  	return err;
  }
  
  static int pcm_close(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	snd_dg00x_stream_lock_release(dg00x);
  
  	return 0;
  }
  
  static int pcm_hw_params(struct snd_pcm_substream *substream,
  			 struct snd_pcm_hw_params *hw_params)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  	int err = 0;
  
  	if (substream->runtime->status->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);
  
  		mutex_lock(&dg00x->mutex);
  		err = snd_dg00x_stream_reserve_duplex(dg00x, rate,
  					frames_per_period, frames_per_buffer);
  		if (err >= 0)
  			++dg00x->substreams_counter;
  		mutex_unlock(&dg00x->mutex);
  	}
  
  	return err;
  }
  
  static int pcm_hw_free(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	mutex_lock(&dg00x->mutex);
  
  	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
  		--dg00x->substreams_counter;
  
  	snd_dg00x_stream_stop_duplex(dg00x);
  
  	mutex_unlock(&dg00x->mutex);
  
  	return 0;
  }
  
  static int pcm_capture_prepare(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  	int err;
  
  	mutex_lock(&dg00x->mutex);
  
  	err = snd_dg00x_stream_start_duplex(dg00x);
  	if (err >= 0)
  		amdtp_stream_pcm_prepare(&dg00x->tx_stream);
  
  	mutex_unlock(&dg00x->mutex);
  
  	return err;
  }
  
  static int pcm_playback_prepare(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  	int err;
  
  	mutex_lock(&dg00x->mutex);
  
  	err = snd_dg00x_stream_start_duplex(dg00x);
  	if (err >= 0) {
  		amdtp_stream_pcm_prepare(&dg00x->rx_stream);
  		amdtp_dot_reset(&dg00x->rx_stream);
  	}
  
  	mutex_unlock(&dg00x->mutex);
  
  	return err;
  }
  
  static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		amdtp_stream_pcm_trigger(&dg00x->tx_stream, substream);
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		amdtp_stream_pcm_trigger(&dg00x->tx_stream, NULL);
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	switch (cmd) {
  	case SNDRV_PCM_TRIGGER_START:
  		amdtp_stream_pcm_trigger(&dg00x->rx_stream, substream);
  		break;
  	case SNDRV_PCM_TRIGGER_STOP:
  		amdtp_stream_pcm_trigger(&dg00x->rx_stream, NULL);
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
  {
  	struct snd_dg00x *dg00x = sbstrm->private_data;
  
  	return amdtp_domain_stream_pcm_pointer(&dg00x->domain, &dg00x->tx_stream);
  }
  
  static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
  {
  	struct snd_dg00x *dg00x = sbstrm->private_data;
  
  	return amdtp_domain_stream_pcm_pointer(&dg00x->domain, &dg00x->rx_stream);
  }
  
  static int pcm_capture_ack(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	return amdtp_domain_stream_pcm_ack(&dg00x->domain, &dg00x->tx_stream);
  }
  
  static int pcm_playback_ack(struct snd_pcm_substream *substream)
  {
  	struct snd_dg00x *dg00x = substream->private_data;
  
  	return amdtp_domain_stream_pcm_ack(&dg00x->domain, &dg00x->rx_stream);
  }
  
  int snd_dg00x_create_pcm_devices(struct snd_dg00x *dg00x)
  {
  	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(dg00x->card, dg00x->card->driver, 0, 1, 1, &pcm);
  	if (err < 0)
  		return err;
  
  	pcm->private_data = dg00x;
  	snprintf(pcm->name, sizeof(pcm->name),
  		 "%s PCM", dg00x->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;
  }
  