circuitpython/ports/atmel-samd/audio_dma.h

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef MICROPY_INCLUDED_ATMEL_SAMD_AUDIO_DMA_H
#define MICROPY_INCLUDED_ATMEL_SAMD_AUDIO_DMA_H

#include "extmod/vfs_fat.h"
#include "py/obj.h"
#include "shared-module/audiocore/RawSample.h"
#include "shared-module/audiocore/WaveFile.h"

typedef struct {
    mp_obj_t sample;
    uint8_t dma_channel;
    uint8_t event_channel;
    uint8_t audio_channel;
    uint8_t bytes_per_sample;
    uint8_t beat_size;
    uint8_t spacing;
    bool loop;
    bool single_channel;
    bool signed_to_unsigned;
    bool unsigned_to_signed;
    bool first_buffer_free;
    uint8_t* first_buffer;
    uint8_t* second_buffer;
    bool first_descriptor_free;
    DmacDescriptor* second_descriptor;
} audio_dma_t;

typedef enum {
    AUDIO_DMA_OK,
    AUDIO_DMA_DMA_BUSY,
    AUDIO_DMA_MEMORY_ERROR,
} audio_dma_result;

uint32_t audiosample_sample_rate(mp_obj_t sample_obj);
uint8_t audiosample_bits_per_sample(mp_obj_t sample_obj);
uint8_t audiosample_channel_count(mp_obj_t sample_obj);

void audio_dma_init(audio_dma_t* dma);
void audio_dma_reset(void);

uint8_t audio_dma_allocate_channel(void);
void audio_dma_free_channel(uint8_t channel);

// This sets everything up but doesn't start the timer.
// Sample is the python object for the sample to play.
// loop is true if we should loop the sample.
// single_channel is true if we only output a single channel. When false, all channels will be
//   output.
// audio_channel is the index of the channel to dma. single_channel must be false in this case.
// output_signed is true if the dma'd data should be signed. False and it will be unsigned.
// output_register_address is the address to copy data to.
// dma_trigger_source is the DMA trigger source which cause another copy
audio_dma_result audio_dma_setup_playback(audio_dma_t* dma,
                                          mp_obj_t sample,
                                          bool loop,
                                          bool single_channel,
                                          uint8_t audio_channel,
                                          bool output_signed,
                                          uint32_t output_register_address,
                                          uint8_t dma_trigger_source);

void audio_dma_disable_channel(uint8_t channel);
void audio_dma_enable_channel(uint8_t channel);
void audio_dma_stop(audio_dma_t* dma);
bool audio_dma_get_playing(audio_dma_t* dma);
void audio_dma_pause(audio_dma_t* dma);
void audio_dma_resume(audio_dma_t* dma);
bool audio_dma_get_paused(audio_dma_t* dma);

void audio_dma_background(void);

#endif  // MICROPY_INCLUDED_ATMEL_SAMD_AUDIO_DMA_H