circuitpython/ports/raspberrypi/audio_dma.h

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2021 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_RASPBERRYPI_AUDIO_DMA_OUT_H
#define MICROPY_INCLUDED_RASPBERRYPI_AUDIO_DMA_OUT_H

#include "py/obj.h"
#include "supervisor/background_callback.h"

#include "src/rp2_common/hardware_dma/include/hardware/dma.h"

typedef struct {
    mp_obj_t sample;
    uint8_t channel[2];
    uint8_t audio_channel;
    uint8_t output_size;
    uint8_t sample_spacing;
    bool loop;
    bool single_channel_output;
    bool signed_to_unsigned;
    bool unsigned_to_signed;
    bool output_signed;
    bool first_channel_free;
    bool first_buffer_free;
    uint8_t output_resolution; // in bits
    uint8_t sample_resolution; // in bits
    uint8_t *first_buffer;
    size_t first_buffer_length;
    uint8_t *second_buffer;
    size_t second_buffer_length;
    uint32_t output_register_address;
    background_callback_t callback;
} audio_dma_t;

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


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

// 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_output 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_output 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_output,
    uint8_t audio_channel,
    bool output_signed,
    uint8_t output_resolution,
    uint32_t output_register_address,
    uint8_t dma_trigger_source);

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);

#endif  // MICROPY_INCLUDED_RASPBERRYPI_AUDIO_DMA_OUT_H