/*
 * dice_pcm.c - a part of driver for DICE based devices
 *
 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
 * Copyright (c) 2014 Takashi Sakamoto <o-takashi@sakamocchi.jp>
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include "dice.h"

static int dice_rate_constraint(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	struct snd_dice *dice = rule->private;

	const struct snd_interval *c =
		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	struct snd_interval *r =
		hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
	struct snd_interval rates = {
		.min = UINT_MAX, .max = 0, .integer = 1
	};
	unsigned int i, rate, mode, *pcm_channels = dice->rx_channels;

	for (i = 0; i < ARRAY_SIZE(snd_dice_rates); ++i) {
		rate = snd_dice_rates[i];
		if (snd_dice_stream_get_rate_mode(dice, rate, &mode) < 0)
			continue;

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

		rates.min = min(rates.min, rate);
		rates.max = max(rates.max, rate);
	}

	return snd_interval_refine(r, &rates);
}

static int dice_channels_constraint(struct snd_pcm_hw_params *params,
				    struct snd_pcm_hw_rule *rule)
{
	struct snd_dice *dice = rule->private;

	const struct snd_interval *r =
		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
	struct snd_interval *c =
		hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
	struct snd_interval channels = {
		.min = UINT_MAX, .max = 0, .integer = 1
	};
	unsigned int i, rate, mode, *pcm_channels = dice->rx_channels;

	for (i = 0; i < ARRAY_SIZE(snd_dice_rates); ++i) {
		rate = snd_dice_rates[i];
		if (snd_dice_stream_get_rate_mode(dice, rate, &mode) < 0)
			continue;

		if (!snd_interval_test(r, rate))
			continue;

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

	return snd_interval_refine(c, &channels);
}


static int pcm_open(struct snd_pcm_substream *substream)
{
	static const struct snd_pcm_hardware hardware = {
		.info = SNDRV_PCM_INFO_MMAP |
			SNDRV_PCM_INFO_MMAP_VALID |
			SNDRV_PCM_INFO_BATCH |
			SNDRV_PCM_INFO_INTERLEAVED |
			SNDRV_PCM_INFO_BLOCK_TRANSFER,
		.formats = AMDTP_OUT_PCM_FORMAT_BITS,
		.channels_min = UINT_MAX,
		.channels_max = 0,
		.buffer_bytes_max = 16 * 1024 * 1024,
		.period_bytes_min = 1,
		.period_bytes_max = UINT_MAX,
		.periods_min = 1,
		.periods_max = UINT_MAX,
	};
	struct snd_dice *dice = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned int i;
	int err;

	err = snd_dice_stream_lock_try(dice);
	if (err < 0)
		goto error;

	runtime->hw = hardware;

	for (i = 0; i < ARRAY_SIZE(snd_dice_rates); ++i) {
		if (dice->clock_caps & (1 << i))
			runtime->hw.rates |=
				snd_pcm_rate_to_rate_bit(snd_dice_rates[i]);
	}
	snd_pcm_limit_hw_rates(runtime);

	for (i = 0; i < 3; ++i) {
		if (dice->rx_channels[i]) {
			runtime->hw.channels_min = min(runtime->hw.channels_min,
						       dice->rx_channels[i]);
			runtime->hw.channels_max = max(runtime->hw.channels_max,
						       dice->rx_channels[i]);
		}
	}

	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
				  dice_rate_constraint, dice,
				  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
	if (err < 0)
		goto err_lock;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
				  dice_channels_constraint, dice,
				  SNDRV_PCM_HW_PARAM_RATE, -1);
	if (err < 0)
		goto err_lock;

	err = amdtp_stream_add_pcm_hw_constraints(&dice->rx_stream, runtime);
	if (err < 0)
		goto err_lock;

	return 0;

err_lock:
	snd_dice_stream_lock_release(dice);
error:
	return err;
}

static int pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_dice *dice = substream->private_data;

	snd_dice_stream_lock_release(dice);

	return 0;
}

static int playback_hw_params(struct snd_pcm_substream *substream,
			      struct snd_pcm_hw_params *hw_params)
{
	struct snd_dice *dice = substream->private_data;
	unsigned int mode, rate, channels, i;
	int err;

	mutex_lock(&dice->mutex);
	snd_dice_stream_stop(dice);
	mutex_unlock(&dice->mutex);

	err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
					       params_buffer_bytes(hw_params));
	if (err < 0)
		return err;

	rate = params_rate(hw_params);
	err = snd_dice_transaction_set_rate(dice, rate);
	if (err < 0)
		return err;

	if (snd_dice_stream_get_rate_mode(dice, rate, &mode) < 0)
		return err;

	/*
	 * At 176.4/192.0 kHz, Dice has a quirk to transfer two PCM frames in
	 * one data block of AMDTP packet. Thus sampling transfer frequency is
	 * a half of PCM sampling frequency, i.e. PCM frames at 192.0 kHz are
	 * transferred on AMDTP packets at 96 kHz. Two successive samples of a
	 * channel are stored consecutively in the packet. This quirk is called
	 * as 'Dual Wire'.
	 * For this quirk, blocking mode is required and PCM buffer size should
	 * be aligned to SYT_INTERVAL.
	 */
	channels = params_channels(hw_params);
	if (mode > 1) {
		if (channels > AMDTP_MAX_CHANNELS_FOR_PCM / 2) {
			err = -ENOSYS;
			return err;
		}

		rate /= 2;
		channels *= 2;
		dice->rx_stream.double_pcm_frames = true;
	} else {
		dice->rx_stream.double_pcm_frames = false;
	}

	amdtp_stream_set_parameters(&dice->rx_stream, rate, channels,
				    dice->rx_midi_ports[mode]);
	if (mode > 1) {
		channels /= 2;

		for (i = 0; i < channels; i++) {
			dice->rx_stream.pcm_positions[i] = i * 2;
			dice->rx_stream.pcm_positions[i + channels] = i * 2 + 1;
		}
	}

	amdtp_stream_set_pcm_format(&dice->rx_stream,
				    params_format(hw_params));

	return 0;
}

static int playback_hw_free(struct snd_pcm_substream *substream)
{
	struct snd_dice *dice = substream->private_data;

	mutex_lock(&dice->mutex);
	snd_dice_stream_stop(dice);
	mutex_unlock(&dice->mutex);

	return snd_pcm_lib_free_vmalloc_buffer(substream);
}

static int playback_prepare(struct snd_pcm_substream *substream)
{
	struct snd_dice *dice = substream->private_data;
	int err;

	mutex_lock(&dice->mutex);

	if (amdtp_streaming_error(&dice->rx_stream))
		snd_dice_stream_stop_packets(dice);

	err = snd_dice_stream_start(dice);
	if (err < 0) {
		mutex_unlock(&dice->mutex);
		return err;
	}

	mutex_unlock(&dice->mutex);

	amdtp_stream_pcm_prepare(&dice->rx_stream);

	return 0;
}

static int playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct snd_dice *dice = substream->private_data;

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

	return 0;
}

static snd_pcm_uframes_t playback_pointer(struct snd_pcm_substream *substream)
{
	struct snd_dice *dice = substream->private_data;

	return amdtp_stream_pcm_pointer(&dice->rx_stream);
}

int snd_dice_create_pcm(struct snd_dice *dice)
{
	static struct snd_pcm_ops playback_ops = {
		.open      = pcm_open,
		.close     = pcm_close,
		.ioctl     = snd_pcm_lib_ioctl,
		.hw_params = playback_hw_params,
		.hw_free   = playback_hw_free,
		.prepare   = playback_prepare,
		.trigger   = playback_trigger,
		.pointer   = playback_pointer,
		.page      = snd_pcm_lib_get_vmalloc_page,
		.mmap      = snd_pcm_lib_mmap_vmalloc,
	};
	struct snd_pcm *pcm;
	int err;

	err = snd_pcm_new(dice->card, "DICE", 0, 1, 0, &pcm);
	if (err < 0)
		return err;
	pcm->private_data = dice;
	strcpy(pcm->name, dice->card->shortname);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &playback_ops);

	return 0;
}