/*
 * 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 limit_channels_and_rates(struct snd_dice *dice,
                                    struct snd_pcm_runtime *runtime,
                                    enum amdtp_stream_direction dir,
                                    unsigned int index, unsigned int size)
{
        struct snd_pcm_hardware *hw = &runtime->hw;
        struct amdtp_stream *stream;
        unsigned int rate;
        __be32 reg;
        int err;

        /*
         * Retrieve current Multi Bit Linear Audio data channel and limit to
         * it.
         */
        if (dir == AMDTP_IN_STREAM) {
                stream = &dice->tx_stream[index];
                err = snd_dice_transaction_read_tx(dice,
                                size * index + TX_NUMBER_AUDIO,
                                &reg, sizeof(reg));
        } else {
                stream = &dice->rx_stream[index];
                err = snd_dice_transaction_read_rx(dice,
                                size * index + RX_NUMBER_AUDIO,
                                &reg, sizeof(reg));
        }
        if (err < 0)
                return err;

        hw->channels_min = hw->channels_max = be32_to_cpu(reg);

        /* Retrieve current sampling transfer frequency and limit to it. */
        err = snd_dice_transaction_get_rate(dice, &rate);
        if (err < 0)
                return err;

        hw->rates = snd_pcm_rate_to_rate_bit(rate);
        snd_pcm_limit_hw_rates(runtime);

        return 0;
}

static int init_hw_info(struct snd_dice *dice,
                        struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_pcm_hardware *hw = &runtime->hw;
        enum amdtp_stream_direction dir;
        struct amdtp_stream *stream;
        __be32 reg[2];
        unsigned int count, size;
        int err;

        if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
                hw->formats = AM824_IN_PCM_FORMAT_BITS;
                dir = AMDTP_IN_STREAM;
                stream = &dice->tx_stream[substream->pcm->device];
                err = snd_dice_transaction_read_tx(dice, TX_NUMBER, reg,
                                                   sizeof(reg));
        } else {
                hw->formats = AM824_OUT_PCM_FORMAT_BITS;
                dir = AMDTP_OUT_STREAM;
                stream = &dice->rx_stream[substream->pcm->device];
                err = snd_dice_transaction_read_rx(dice, RX_NUMBER, reg,
                                                   sizeof(reg));
        }

        if (err < 0)
                return err;

        count = min_t(unsigned int, be32_to_cpu(reg[0]), MAX_STREAMS);
        if (substream->pcm->device >= count)
                return -ENXIO;

        size = be32_to_cpu(reg[1]) * 4;
        err = limit_channels_and_rates(dice, substream->runtime, dir,
                                       substream->pcm->device, size);
        if (err < 0)
                return err;

        return amdtp_am824_add_pcm_hw_constraints(stream, runtime);
}

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

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

        err = init_hw_info(dice, substream);
        if (err < 0)
                goto err_locked;

        snd_pcm_set_sync(substream);
end:
        return err;
err_locked:
        snd_dice_stream_lock_release(dice);
        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 capture_hw_params(struct snd_pcm_substream *substream,
                             struct snd_pcm_hw_params *hw_params)
{
        struct snd_dice *dice = substream->private_data;
        int err;

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

        if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
                mutex_lock(&dice->mutex);
                dice->substreams_counter++;
                mutex_unlock(&dice->mutex);
        }

        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;
        int err;

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

        if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
                mutex_lock(&dice->mutex);
                dice->substreams_counter++;
                mutex_unlock(&dice->mutex);
        }

        return 0;
}

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

        mutex_lock(&dice->mutex);

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

        snd_dice_stream_stop_duplex(dice);

        mutex_unlock(&dice->mutex);

        return snd_pcm_lib_free_vmalloc_buffer(substream);
}

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

        mutex_lock(&dice->mutex);

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

        snd_dice_stream_stop_duplex(dice);

        mutex_unlock(&dice->mutex);

        return snd_pcm_lib_free_vmalloc_buffer(substream);
}

static int capture_prepare(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->tx_stream[substream->pcm->device];
        int err;

        mutex_lock(&dice->mutex);
        err = snd_dice_stream_start_duplex(dice, substream->runtime->rate);
        mutex_unlock(&dice->mutex);
        if (err >= 0)
                amdtp_stream_pcm_prepare(stream);

        return 0;
}
static int playback_prepare(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->rx_stream[substream->pcm->device];
        int err;

        mutex_lock(&dice->mutex);
        err = snd_dice_stream_start_duplex(dice, substream->runtime->rate);
        mutex_unlock(&dice->mutex);
        if (err >= 0)
                amdtp_stream_pcm_prepare(stream);

        return err;
}

static int capture_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->tx_stream[substream->pcm->device];

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

        return 0;
}
static int playback_trigger(struct snd_pcm_substream *substream, int cmd)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->rx_stream[substream->pcm->device];

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

        return 0;
}

static snd_pcm_uframes_t capture_pointer(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->tx_stream[substream->pcm->device];

        return amdtp_stream_pcm_pointer(stream);
}
static snd_pcm_uframes_t playback_pointer(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->rx_stream[substream->pcm->device];

        return amdtp_stream_pcm_pointer(stream);
}

static int capture_ack(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->tx_stream[substream->pcm->device];

        return amdtp_stream_pcm_ack(stream);
}

static int playback_ack(struct snd_pcm_substream *substream)
{
        struct snd_dice *dice = substream->private_data;
        struct amdtp_stream *stream = &dice->rx_stream[substream->pcm->device];

        return amdtp_stream_pcm_ack(stream);
}

int snd_dice_create_pcm(struct snd_dice *dice)
{
        static const struct snd_pcm_ops capture_ops = {
                .open      = pcm_open,
                .close     = pcm_close,
                .ioctl     = snd_pcm_lib_ioctl,
                .hw_params = capture_hw_params,
                .hw_free   = capture_hw_free,
                .prepare   = capture_prepare,
                .trigger   = capture_trigger,
                .pointer   = capture_pointer,
                .ack       = capture_ack,
                .page      = snd_pcm_lib_get_vmalloc_page,
                .mmap      = snd_pcm_lib_mmap_vmalloc,
        };
        static const 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,
                .ack       = playback_ack,
                .page      = snd_pcm_lib_get_vmalloc_page,
                .mmap      = snd_pcm_lib_mmap_vmalloc,
        };
        __be32 reg;
        struct snd_pcm *pcm;
        unsigned int i, max_capture, max_playback, capture, playback;
        int err;

        /* Check whether PCM substreams are required. */
        if (dice->force_two_pcms) {
                max_capture = max_playback = 2;
        } else {
                max_capture = max_playback = 0;
                err = snd_dice_transaction_read_tx(dice, TX_NUMBER, &reg,
                                                   sizeof(reg));
                if (err < 0)
                        return err;
                max_capture = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);

                err = snd_dice_transaction_read_rx(dice, RX_NUMBER, &reg,
                                                   sizeof(reg));
                if (err < 0)
                        return err;
                max_playback = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);
        }

        for (i = 0; i < MAX_STREAMS; i++) {
                capture = playback = 0;
                if (i < max_capture)
                        capture = 1;
                if (i < max_playback)
                        playback = 1;
                if (capture == 0 && playback == 0)
                        break;

                err = snd_pcm_new(dice->card, "DICE", i, playback, capture,
                                  &pcm);
                if (err < 0)
                        return err;
                pcm->private_data = dice;
                strcpy(pcm->name, dice->card->shortname);

                if (capture > 0)
                        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
                                        &capture_ops);

                if (playback > 0)
                        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
                                        &playback_ops);
        }

        return 0;
}