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circuitpython/ports/atmel-samd/audio_dma.c

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/*
* 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.
*/
#include "audio_dma.h"
#include "samd/clocks.h"
#include "samd/events.h"
#include "samd/dma.h"
#include "shared-bindings/audiocore/RawSample.h"
#include "shared-bindings/audiocore/WaveFile.h"
#include "supervisor/shared/tick.h"
#include "py/mpstate.h"
#include "py/runtime.h"
#if CIRCUITPY_AUDIOIO || CIRCUITPY_AUDIOBUSIO
static audio_dma_t* audio_dma_state[AUDIO_DMA_CHANNEL_COUNT];
// This cannot be in audio_dma_state because it's volatile.
static volatile bool audio_dma_pending[AUDIO_DMA_CHANNEL_COUNT];
static bool audio_dma_allocated[AUDIO_DMA_CHANNEL_COUNT];
uint8_t audio_dma_allocate_channel(void) {
uint8_t channel;
for (channel = 0; channel < AUDIO_DMA_CHANNEL_COUNT; channel++) {
if (!audio_dma_allocated[channel]) {
audio_dma_allocated[channel] = true;
return channel;
}
}
return channel; // i.e., return failure
}
void audio_dma_free_channel(uint8_t channel) {
assert(channel < AUDIO_DMA_CHANNEL_COUNT);
assert(audio_dma_allocated[channel]);
audio_dma_disable_channel(channel);
audio_dma_allocated[channel] = false;
supervisor_disable_tick();
}
void audio_dma_disable_channel(uint8_t channel) {
if (channel >= AUDIO_DMA_CHANNEL_COUNT)
return;
dma_disable_channel(channel);
}
void audio_dma_enable_channel(uint8_t channel) {
if (channel >= AUDIO_DMA_CHANNEL_COUNT)
return;
supervisor_enable_tick();
dma_enable_channel(channel);
}
void audio_dma_convert_signed(audio_dma_t* dma, uint8_t* buffer, uint32_t buffer_length,
uint8_t** output_buffer, uint32_t* output_buffer_length,
uint8_t* output_spacing) {
if (dma->first_buffer_free) {
*output_buffer = dma->first_buffer;
} else {
*output_buffer = dma->second_buffer;
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-align"
if (dma->signed_to_unsigned || dma->unsigned_to_signed) {
*output_buffer_length = buffer_length / dma->spacing;
*output_spacing = 1;
uint32_t out_i = 0;
if (dma->bytes_per_sample == 1) {
for (uint32_t i = 0; i < buffer_length; i += dma->spacing) {
if (dma->signed_to_unsigned) {
((uint8_t*) *output_buffer)[out_i] = ((int8_t*) buffer)[i] + 0x80;
} else {
((int8_t*) *output_buffer)[out_i] = ((uint8_t*) buffer)[i] - 0x80;
}
out_i += 1;
}
} else if (dma->bytes_per_sample == 2) {
for (uint32_t i = 0; i < buffer_length / 2; i += dma->spacing) {
if (dma->signed_to_unsigned) {
((uint16_t*) *output_buffer)[out_i] = ((int16_t*) buffer)[i] + 0x8000;
} else {
((int16_t*) *output_buffer)[out_i] = ((uint16_t*) buffer)[i] - 0x8000;
}
out_i += 1;
}
}
} else {
*output_buffer = buffer;
*output_buffer_length = buffer_length;
*output_spacing = dma->spacing;
}
#pragma GCC diagnostic pop
dma->first_buffer_free = !dma->first_buffer_free;
}
void audio_dma_load_next_block(audio_dma_t* dma) {
uint8_t* buffer;
uint32_t buffer_length;
audioio_get_buffer_result_t get_buffer_result =
audiosample_get_buffer(dma->sample, dma->single_channel, dma->audio_channel,
&buffer, &buffer_length);
DmacDescriptor* descriptor = dma->second_descriptor;
if (dma->first_descriptor_free) {
descriptor = dma_descriptor(dma->dma_channel);
}
dma->first_descriptor_free = !dma->first_descriptor_free;
if (get_buffer_result == GET_BUFFER_ERROR) {
audio_dma_stop(dma);
return;
}
uint8_t* output_buffer;
uint32_t output_buffer_length;
uint8_t output_spacing;
audio_dma_convert_signed(dma, buffer, buffer_length, &output_buffer, &output_buffer_length,
&output_spacing);
descriptor->BTCNT.reg = output_buffer_length / dma->beat_size / output_spacing;
descriptor->SRCADDR.reg = ((uint32_t) output_buffer) + output_buffer_length;
if (get_buffer_result == GET_BUFFER_DONE) {
if (dma->loop) {
audiosample_reset_buffer(dma->sample, dma->single_channel, dma->audio_channel);
} else {
descriptor->DESCADDR.reg = 0;
}
}
descriptor->BTCTRL.bit.VALID = true;
}
static void setup_audio_descriptor(DmacDescriptor* descriptor, uint8_t beat_size,
uint8_t spacing, uint32_t output_register_address) {
uint32_t beat_size_reg = DMAC_BTCTRL_BEATSIZE_BYTE;
if (beat_size == 2) {
beat_size_reg = DMAC_BTCTRL_BEATSIZE_HWORD;
} else if (beat_size == 4) {
beat_size_reg = DMAC_BTCTRL_BEATSIZE_WORD;
}
descriptor->BTCTRL.reg = beat_size_reg |
DMAC_BTCTRL_SRCINC |
DMAC_BTCTRL_EVOSEL_BLOCK |
DMAC_BTCTRL_STEPSIZE(spacing - 1) |
DMAC_BTCTRL_STEPSEL_SRC;
descriptor->DSTADDR.reg = output_register_address;
}
// Playback should be shutdown before calling this.
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) {
uint8_t dma_channel = audio_dma_allocate_channel();
if (dma_channel >= AUDIO_DMA_CHANNEL_COUNT) {
return AUDIO_DMA_DMA_BUSY;
}
dma->sample = sample;
dma->loop = loop;
dma->single_channel = single_channel;
dma->audio_channel = audio_channel;
dma->dma_channel = dma_channel;
dma->signed_to_unsigned = false;
dma->unsigned_to_signed = false;
dma->second_descriptor = NULL;
dma->spacing = 1;
dma->first_descriptor_free = true;
audiosample_reset_buffer(sample, single_channel, audio_channel);
bool single_buffer;
bool samples_signed;
uint32_t max_buffer_length;
audiosample_get_buffer_structure(sample, single_channel, &single_buffer, &samples_signed,
&max_buffer_length, &dma->spacing);
uint8_t output_spacing = dma->spacing;
if (output_signed != samples_signed) {
output_spacing = 1;
max_buffer_length /= dma->spacing;
dma->first_buffer = (uint8_t*) m_realloc(dma->first_buffer, max_buffer_length);
if (dma->first_buffer == NULL) {
return AUDIO_DMA_MEMORY_ERROR;
}
dma->first_buffer_free = true;
if (!single_buffer) {
dma->second_buffer = (uint8_t*) m_realloc(dma->second_buffer, max_buffer_length);
if (dma->second_buffer == NULL) {
return AUDIO_DMA_MEMORY_ERROR;
}
}
dma->signed_to_unsigned = !output_signed && samples_signed;
dma->unsigned_to_signed = output_signed && !samples_signed;
}
dma->event_channel = 0xff;
if (!single_buffer) {
dma->second_descriptor = (DmacDescriptor*) m_malloc(sizeof(DmacDescriptor), false);
if (dma->second_descriptor == NULL) {
return AUDIO_DMA_MEMORY_ERROR;
}
// We're likely double buffering so set up the block interrupts.
turn_on_event_system();
dma->event_channel = find_sync_event_channel();
if (dma->event_channel >= EVSYS_SYNCH_NUM) {
mp_raise_RuntimeError(translate("All sync event channels in use"));
}
init_event_channel_interrupt(dma->event_channel, CORE_GCLK, EVSYS_ID_GEN_DMAC_CH_0 + dma_channel);
// We keep the audio_dma_t for internal use and the sample as a root pointer because it
// contains the audiodma structure.
audio_dma_state[dma->dma_channel] = dma;
MP_STATE_PORT(playing_audio)[dma->dma_channel] = dma->sample;
}
if (audiosample_bits_per_sample(sample) == 16) {
dma->beat_size = 2;
dma->bytes_per_sample = 2;
} else {
dma->beat_size = 1;
dma->bytes_per_sample = 1;
if (single_channel) {
output_register_address += 1;
}
}
// Transfer both channels at once.
if (!single_channel && audiosample_channel_count(sample) == 2) {
dma->beat_size *= 2;
}
DmacDescriptor* first_descriptor = dma_descriptor(dma_channel);
setup_audio_descriptor(first_descriptor, dma->beat_size, output_spacing, output_register_address);
if (single_buffer) {
first_descriptor->DESCADDR.reg = 0;
if (dma->loop) {
first_descriptor->DESCADDR.reg = (uint32_t) first_descriptor;
}
} else {
first_descriptor->DESCADDR.reg = (uint32_t) dma->second_descriptor;
setup_audio_descriptor(dma->second_descriptor, dma->beat_size, output_spacing, output_register_address);
dma->second_descriptor->DESCADDR.reg = (uint32_t) first_descriptor;
}
// Load the first two blocks up front.
audio_dma_load_next_block(dma);
if (!single_buffer) {
audio_dma_load_next_block(dma);
}
dma_configure(dma_channel, dma_trigger_source, true);
audio_dma_enable_channel(dma_channel);
return AUDIO_DMA_OK;
}
void audio_dma_stop(audio_dma_t* dma) {
uint8_t channel = dma->dma_channel;
if (channel < AUDIO_DMA_CHANNEL_COUNT) {
audio_dma_disable_channel(channel);
disable_event_channel(dma->event_channel);
MP_STATE_PORT(playing_audio)[channel] = NULL;
audio_dma_state[channel] = NULL;
audio_dma_free_channel(dma->dma_channel);
}
dma->dma_channel = AUDIO_DMA_CHANNEL_COUNT;
}
void audio_dma_pause(audio_dma_t* dma) {
dma_suspend_channel(dma->dma_channel);
}
void audio_dma_resume(audio_dma_t* dma) {
dma_resume_channel(dma->dma_channel);
}
bool audio_dma_get_paused(audio_dma_t* dma) {
if (dma->dma_channel >= AUDIO_DMA_CHANNEL_COUNT) {
return false;
}
uint32_t status = dma_transfer_status(dma->dma_channel);
return (status & DMAC_CHINTFLAG_SUSP) != 0;
}
void audio_dma_init(audio_dma_t* dma) {
dma->dma_channel = AUDIO_DMA_CHANNEL_COUNT;
}
void audio_dma_reset(void) {
for (uint8_t i = 0; i < AUDIO_DMA_CHANNEL_COUNT; i++) {
audio_dma_state[i] = NULL;
audio_dma_pending[i] = false;
if (audio_dma_allocated[i]) {
supervisor_disable_tick();
}
audio_dma_allocated[i] = false;
audio_dma_disable_channel(i);
dma_descriptor(i)->BTCTRL.bit.VALID = false;
MP_STATE_PORT(playing_audio)[i] = NULL;
}
}
bool audio_dma_get_playing(audio_dma_t* dma) {
if (dma->dma_channel >= AUDIO_DMA_CHANNEL_COUNT) {
return false;
}
uint32_t status = dma_transfer_status(dma->dma_channel);
if ((status & DMAC_CHINTFLAG_TCMPL) != 0 || (status & DMAC_CHINTFLAG_TERR) != 0) {
audio_dma_stop(dma);
}
return (status & DMAC_CHINTFLAG_TERR) == 0;
}
// WARN(tannewt): DO NOT print from here. Printing calls background tasks such as this and causes a
// stack overflow.
void audio_dma_background(void) {
for (uint8_t i = 0; i < AUDIO_DMA_CHANNEL_COUNT; i++) {
if (audio_dma_pending[i]) {
continue;
}
audio_dma_t* dma = audio_dma_state[i];
if (dma == NULL) {
continue;
}
bool block_done = event_interrupt_active(dma->event_channel);
if (!block_done) {
continue;
}
// audio_dma_load_next_block() can call Python code, which can call audio_dma_background()
// recursively at the next background processing time. So disallow recursive calls to here.
audio_dma_pending[i] = true;
audio_dma_load_next_block(dma);
audio_dma_pending[i] = false;
}
}
#endif
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