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micropython/ports/stm32/machine_i2s.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015 Bryan Morrissey
* Copyright (c) 2021 Mike Teachman
*
* 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 <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include "py/obj.h"
#include "py/runtime.h"
#include "py/mphal.h"
#include "py/misc.h"
#include "py/stream.h"
#include "py/objstr.h"
#include "modmachine.h"
#include "pin.h"
#include "dma.h"
#if MICROPY_HW_ENABLE_I2S
// The I2S module has 3 modes of operation:
//
// Mode1: Blocking
// - readinto() and write() methods block until the supplied buffer is filled (read) or emptied (write)
// - this is the default mode of operation
//
// Mode2: Non-Blocking
// - readinto() and write() methods return immediately
// - buffer filling and emptying happens asynchronously to the main MicroPython task
// - a callback function is called when the supplied buffer has been filled (read) or emptied (write)
// - non-blocking mode is enabled when a callback is set with the irq() method
// - the DMA callbacks (1/2 complete and complete) are used to implement the asynchronous background operations
//
// Mode3: Uasyncio
// - implements the stream protocol
// - uasyncio mode is enabled when the ioctl() function is called
// - the state of the internal ring buffer is used to detect that I2S samples can be read or written
//
// The samples contained in the app buffer supplied for the readinto() and write() methods have the following convention:
// Mono: little endian format
// Stereo: little endian format, left channel first
//
// I2S terms:
// "frame": consists of two audio samples (Left audio sample + Right audio sample)
//
// Misc:
// - for Mono configuration:
// - readinto method: samples are gathered from the L channel only
// - write method: every sample is output to both the L and R channels
// - for readinto method the I2S hardware is read using 8-byte frames
// (this is standard for almost all I2S hardware, such as MEMS microphones)
// - all 3 Modes of operation are implemented using the HAL I2S Generic Driver
// - all sample data transfers use DMA
// - the DMA controller is configured in Circular mode to fulfil continuous and gapless sample flows
// - the DMA ping-pong buffer needs to be aligned to a cache line size of 32 bytes. 32 byte
// alignment is needed to use the routines that clean and invalidate D-Cache which work on a
// 32 byte address boundary. Not all STM32 devices have a D-Cache. Buffer alignment
// will still happen on these devices to keep this code simple.
#define MAX_I2S_STM32 (2)
// DMA ping-pong buffer size was empirically determined. It is a tradeoff between:
// 1. memory use (smaller buffer size desirable to reduce memory footprint)
// 2. interrupt frequency (larger buffer size desirable to reduce interrupt frequency)
// The sizeof 1/2 of the DMA buffer must be evenly divisible by the cache line size of 32 bytes.
#define SIZEOF_DMA_BUFFER_IN_BYTES (256)
#define SIZEOF_HALF_DMA_BUFFER_IN_BYTES (SIZEOF_DMA_BUFFER_IN_BYTES / 2)
// For non-blocking mode, to avoid underflow/overflow, sample data is written/read to/from the ring buffer at a rate faster
// than the DMA transfer rate
#define NON_BLOCKING_RATE_MULTIPLIER (4)
#define SIZEOF_NON_BLOCKING_COPY_IN_BYTES (SIZEOF_HALF_DMA_BUFFER_IN_BYTES * NON_BLOCKING_RATE_MULTIPLIER)
#define NUM_I2S_USER_FORMATS (4)
#define I2S_RX_FRAME_SIZE_IN_BYTES (8)
typedef enum {
MONO,
STEREO
} format_t;
typedef enum {
BLOCKING,
NON_BLOCKING,
UASYNCIO
} io_mode_t;
typedef enum {
TOP_HALF,
BOTTOM_HALF
} ping_pong_t;
typedef struct _ring_buf_t {
uint8_t *buffer;
size_t head;
size_t tail;
size_t size;
} ring_buf_t;
typedef struct _non_blocking_descriptor_t {
mp_buffer_info_t appbuf;
uint32_t index;
bool copy_in_progress;
} non_blocking_descriptor_t;
typedef struct _machine_i2s_obj_t {
mp_obj_base_t base;
uint8_t i2s_id;
mp_hal_pin_obj_t sck;
mp_hal_pin_obj_t ws;
mp_hal_pin_obj_t sd;
uint16_t mode;
int8_t bits;
format_t format;
int32_t rate;
int32_t ibuf;
mp_obj_t callback_for_non_blocking;
uint8_t dma_buffer[SIZEOF_DMA_BUFFER_IN_BYTES + 0x1f]; // 0x1f related to D-Cache alignment
uint8_t *dma_buffer_dcache_aligned;
ring_buf_t ring_buffer;
uint8_t *ring_buffer_storage;
non_blocking_descriptor_t non_blocking_descriptor;
io_mode_t io_mode;
I2S_HandleTypeDef hi2s;
DMA_HandleTypeDef hdma_tx;
DMA_HandleTypeDef hdma_rx;
const dma_descr_t *dma_descr_tx;
const dma_descr_t *dma_descr_rx;
} machine_i2s_obj_t;
STATIC mp_obj_t machine_i2s_deinit(mp_obj_t self_in);
// The frame map is used with the readinto() method to transform the audio sample data coming
// from DMA memory (32-bit stereo) to the format specified
// in the I2S constructor. e.g. 16-bit mono
STATIC const int8_t i2s_frame_map[NUM_I2S_USER_FORMATS][I2S_RX_FRAME_SIZE_IN_BYTES] = {
{ 0, 1, -1, -1, -1, -1, -1, -1 }, // Mono, 16-bits
{ 2, 3, 0, 1, -1, -1, -1, -1 }, // Mono, 32-bits
{ 0, 1, 4, 5, -1, -1, -1, -1 }, // Stereo, 16-bits
{ 2, 3, 0, 1, 6, 7, 4, 5 }, // Stereo, 32-bits
};
STATIC machine_i2s_obj_t *machine_i2s_obj[MAX_I2S_STM32];
void machine_i2s_init0() {
for (uint8_t i = 0; i < MAX_I2S_STM32; i++) {
machine_i2s_obj[i] = NULL;
}
}
// Ring Buffer
// Thread safe when used with these constraints:
// - Single Producer, Single Consumer
// - Sequential atomic operations
// One byte of capacity is used to detect buffer empty/full
STATIC void ringbuf_init(ring_buf_t *rbuf, uint8_t *buffer, size_t size) {
rbuf->buffer = buffer;
rbuf->size = size;
rbuf->head = 0;
rbuf->tail = 0;
}
STATIC bool ringbuf_push(ring_buf_t *rbuf, uint8_t data) {
size_t next_tail = (rbuf->tail + 1) % rbuf->size;
if (next_tail != rbuf->head) {
rbuf->buffer[rbuf->tail] = data;
rbuf->tail = next_tail;
return true;
}
// full
return false;
}
STATIC bool ringbuf_pop(ring_buf_t *rbuf, uint8_t *data) {
if (rbuf->head == rbuf->tail) {
// empty
return false;
}
*data = rbuf->buffer[rbuf->head];
rbuf->head = (rbuf->head + 1) % rbuf->size;
return true;
}
STATIC bool ringbuf_is_empty(ring_buf_t *rbuf) {
return rbuf->head == rbuf->tail;
}
STATIC bool ringbuf_is_full(ring_buf_t *rbuf) {
return ((rbuf->tail + 1) % rbuf->size) == rbuf->head;
}
STATIC size_t ringbuf_available_data(ring_buf_t *rbuf) {
return (rbuf->tail - rbuf->head + rbuf->size) % rbuf->size;
}
STATIC size_t ringbuf_available_space(ring_buf_t *rbuf) {
return rbuf->size - ringbuf_available_data(rbuf) - 1;
}
// For 32-bit audio samples, the STM32 HAL API expects each 32-bit sample to be encoded
// in an unusual byte ordering: Byte_2, Byte_3, Byte_0, Byte_1
// where: Byte_0 is the least significant byte of the 32-bit sample
//
// The following function takes a buffer containing 32-bits sample values formatted as little endian
// and performs an in-place modification into the STM32 HAL API convention
//
// Example:
//
// wav_samples[] = [L_0-7, L_8-15, L_16-23, L_24-31, R_0-7, R_8-15, R_16-23, R_24-31] = [Left channel, Right channel]
// stm_api[] = [L_16-23, L_24-31, L_0-7, L_8-15, R_16-23, R_24-31, R_0-7, R_8-15] = [Left channel, Right channel]
//
// where:
// L_0-7 is the least significant byte of the 32 bit sample in the Left channel
// L_24-31 is the most significant byte of the 32 bit sample in the Left channel
//
// wav_samples[] = [0x99, 0xBB, 0x11, 0x22, 0x44, 0x55, 0xAB, 0x77] = [Left channel, Right channel]
// stm_api[] = [0x11, 0x22, 0x99, 0xBB, 0xAB, 0x77, 0x44, 0x55] = [Left channel, Right channel]
//
// where:
// LEFT Channel = 0x99, 0xBB, 0x11, 0x22
// RIGHT Channel = 0x44, 0x55, 0xAB, 0x77
STATIC void reformat_32_bit_samples(int32_t *sample, uint32_t num_samples) {
int16_t sample_ms;
int16_t sample_ls;
for (uint32_t i = 0; i < num_samples; i++) {
sample_ls = sample[i] & 0xFFFF;
sample_ms = sample[i] >> 16;
sample[i] = (sample_ls << 16) + sample_ms;
}
}
STATIC int8_t get_frame_mapping_index(int8_t bits, format_t format) {
if (format == MONO) {
if (bits == 16) {
return 0;
} else { // 32 bits
return 1;
}
} else { // STEREO
if (bits == 16) {
return 2;
} else { // 32 bits
return 3;
}
}
}
STATIC int8_t get_dma_bits(uint16_t mode, int8_t bits) {
if (mode == I2S_MODE_MASTER_TX) {
if (bits == 16) {
return I2S_DATAFORMAT_16B;
} else {
return I2S_DATAFORMAT_32B;
}
return bits;
} else { // Master Rx
// always read 32 bit words for I2S e.g. I2S MEMS microphones
return I2S_DATAFORMAT_32B;
}
}
STATIC uint32_t fill_appbuf_from_ringbuf(machine_i2s_obj_t *self, mp_buffer_info_t *appbuf) {
// copy audio samples from the ring buffer to the app buffer
// loop, copying samples until the app buffer is filled
// For uasyncio mode, the loop will make an early exit if the ring buffer becomes empty
// Example:
// a MicroPython I2S object is configured for 16-bit mono (2 bytes per audio sample).
// For every frame coming from the ring buffer (8 bytes), 2 bytes are "cherry picked" and
// copied to the supplied app buffer.
// Thus, for every 1 byte copied to the app buffer, 4 bytes are read from the ring buffer.
// If a 8kB app buffer is supplied, 32kB of audio samples is read from the ring buffer.
uint32_t num_bytes_copied_to_appbuf = 0;
uint8_t *app_p = (uint8_t *)appbuf->buf;
uint8_t appbuf_sample_size_in_bytes = (self->bits == 16? 2 : 4) * (self->format == STEREO ? 2: 1);
uint32_t num_bytes_needed_from_ringbuf = appbuf->len * (I2S_RX_FRAME_SIZE_IN_BYTES / appbuf_sample_size_in_bytes);
uint8_t discard_byte;
while (num_bytes_needed_from_ringbuf) {
uint8_t f_index = get_frame_mapping_index(self->bits, self->format);
for (uint8_t i = 0; i < I2S_RX_FRAME_SIZE_IN_BYTES; i++) {
int8_t r_to_a_mapping = i2s_frame_map[f_index][i];
if (r_to_a_mapping != -1) {
if (self->io_mode == BLOCKING) {
// poll the ringbuf until a sample becomes available, copy into appbuf using the mapping transform
while (ringbuf_pop(&self->ring_buffer, app_p + r_to_a_mapping) == false) {
;
}
num_bytes_copied_to_appbuf++;
} else if (self->io_mode == UASYNCIO) {
if (ringbuf_pop(&self->ring_buffer, app_p + r_to_a_mapping) == false) {
// ring buffer is empty, exit
goto exit;
} else {
num_bytes_copied_to_appbuf++;
}
} else {
return 0; // should never get here (non-blocking mode does not use this function)
}
} else { // r_a_mapping == -1
// discard unused byte from ring buffer
if (self->io_mode == BLOCKING) {
// poll the ringbuf until a sample becomes available
while (ringbuf_pop(&self->ring_buffer, &discard_byte) == false) {
;
}
} else if (self->io_mode == UASYNCIO) {
if (ringbuf_pop(&self->ring_buffer, &discard_byte) == false) {
// ring buffer is empty, exit
goto exit;
}
} else {
return 0; // should never get here (non-blocking mode does not use this function)
}
}
num_bytes_needed_from_ringbuf--;
}
app_p += appbuf_sample_size_in_bytes;
}
exit:
return num_bytes_copied_to_appbuf;
}
// function is used in IRQ context
STATIC void fill_appbuf_from_ringbuf_non_blocking(machine_i2s_obj_t *self) {
// attempt to copy a block of audio samples from the ring buffer to the supplied app buffer.
// audio samples will be formatted as part of the copy operation
uint32_t num_bytes_copied_to_appbuf = 0;
uint8_t *app_p = &(((uint8_t *)self->non_blocking_descriptor.appbuf.buf)[self->non_blocking_descriptor.index]);
uint8_t appbuf_sample_size_in_bytes = (self->bits == 16? 2 : 4) * (self->format == STEREO ? 2: 1);
uint32_t num_bytes_remaining_to_copy_to_appbuf = self->non_blocking_descriptor.appbuf.len - self->non_blocking_descriptor.index;
uint32_t num_bytes_remaining_to_copy_from_ring_buffer = num_bytes_remaining_to_copy_to_appbuf *
(I2S_RX_FRAME_SIZE_IN_BYTES / appbuf_sample_size_in_bytes);
uint32_t num_bytes_needed_from_ringbuf = MIN(SIZEOF_NON_BLOCKING_COPY_IN_BYTES, num_bytes_remaining_to_copy_from_ring_buffer);
uint8_t discard_byte;
if (ringbuf_available_data(&self->ring_buffer) >= num_bytes_needed_from_ringbuf) {
while (num_bytes_needed_from_ringbuf) {
uint8_t f_index = get_frame_mapping_index(self->bits, self->format);
for (uint8_t i = 0; i < I2S_RX_FRAME_SIZE_IN_BYTES; i++) {
int8_t r_to_a_mapping = i2s_frame_map[f_index][i];
if (r_to_a_mapping != -1) {
ringbuf_pop(&self->ring_buffer, app_p + r_to_a_mapping);
num_bytes_copied_to_appbuf++;
} else { // r_a_mapping == -1
// discard unused byte from ring buffer
ringbuf_pop(&self->ring_buffer, &discard_byte);
}
num_bytes_needed_from_ringbuf--;
}
app_p += appbuf_sample_size_in_bytes;
}
self->non_blocking_descriptor.index += num_bytes_copied_to_appbuf;
if (self->non_blocking_descriptor.index >= self->non_blocking_descriptor.appbuf.len) {
self->non_blocking_descriptor.copy_in_progress = false;
mp_sched_schedule(self->callback_for_non_blocking, MP_OBJ_FROM_PTR(self));
}
}
}
STATIC uint32_t copy_appbuf_to_ringbuf(machine_i2s_obj_t *self, mp_buffer_info_t *appbuf) {
// copy audio samples from the app buffer to the ring buffer
// loop, reading samples until the app buffer is emptied
// for uasyncio mode, the loop will make an early exit if the ring buffer becomes full
uint32_t a_index = 0;
while (a_index < appbuf->len) {
if (self->io_mode == BLOCKING) {
// copy a byte to the ringbuf when space becomes available
while (ringbuf_push(&self->ring_buffer, ((uint8_t *)appbuf->buf)[a_index]) == false) {
;
}
a_index++;
} else if (self->io_mode == UASYNCIO) {
if (ringbuf_push(&self->ring_buffer, ((uint8_t *)appbuf->buf)[a_index]) == false) {
// ring buffer is full, exit
break;
} else {
a_index++;
}
} else {
return 0; // should never get here (non-blocking mode does not use this function)
}
}
return a_index;
}
// function is used in IRQ context
STATIC void copy_appbuf_to_ringbuf_non_blocking(machine_i2s_obj_t *self) {
// copy audio samples from app buffer into ring buffer
uint32_t num_bytes_remaining_to_copy = self->non_blocking_descriptor.appbuf.len - self->non_blocking_descriptor.index;
uint32_t num_bytes_to_copy = MIN(SIZEOF_NON_BLOCKING_COPY_IN_BYTES, num_bytes_remaining_to_copy);
if (ringbuf_available_space(&self->ring_buffer) >= num_bytes_to_copy) {
for (uint32_t i = 0; i < num_bytes_to_copy; i++) {
ringbuf_push(&self->ring_buffer,
((uint8_t *)self->non_blocking_descriptor.appbuf.buf)[self->non_blocking_descriptor.index + i]);
}
self->non_blocking_descriptor.index += num_bytes_to_copy;
if (self->non_blocking_descriptor.index >= self->non_blocking_descriptor.appbuf.len) {
self->non_blocking_descriptor.copy_in_progress = false;
mp_sched_schedule(self->callback_for_non_blocking, MP_OBJ_FROM_PTR(self));
}
}
}
// function is used in IRQ context
STATIC void empty_dma(machine_i2s_obj_t *self, ping_pong_t dma_ping_pong) {
uint16_t dma_buffer_offset = 0;
if (dma_ping_pong == TOP_HALF) {
dma_buffer_offset = 0;
} else { // BOTTOM_HALF
dma_buffer_offset = SIZEOF_HALF_DMA_BUFFER_IN_BYTES;
}
uint8_t *dma_buffer_p = &self->dma_buffer_dcache_aligned[dma_buffer_offset];
// flush and invalidate cache so the CPU reads data placed into RAM by DMA
MP_HAL_CLEANINVALIDATE_DCACHE(dma_buffer_p, SIZEOF_HALF_DMA_BUFFER_IN_BYTES);
// when space exists, copy samples into ring buffer
if (ringbuf_available_space(&self->ring_buffer) >= SIZEOF_HALF_DMA_BUFFER_IN_BYTES) {
for (uint32_t i = 0; i < SIZEOF_HALF_DMA_BUFFER_IN_BYTES; i++) {
ringbuf_push(&self->ring_buffer, dma_buffer_p[i]);
}
}
}
// function is used in IRQ context
STATIC void feed_dma(machine_i2s_obj_t *self, ping_pong_t dma_ping_pong) {
uint16_t dma_buffer_offset = 0;
if (dma_ping_pong == TOP_HALF) {
dma_buffer_offset = 0;
} else { // BOTTOM_HALF
dma_buffer_offset = SIZEOF_HALF_DMA_BUFFER_IN_BYTES;
}
uint8_t *dma_buffer_p = &self->dma_buffer_dcache_aligned[dma_buffer_offset];
// when data exists, copy samples from ring buffer
if (ringbuf_available_data(&self->ring_buffer) >= SIZEOF_HALF_DMA_BUFFER_IN_BYTES) {
// copy a block of samples from the ring buffer to the dma buffer.
// STM32 HAL API has a stereo I2S implementation, but not mono
// mono format is implemented by duplicating each sample into both L and R channels.
if ((self->format == MONO) && (self->bits == 16)) {
for (uint32_t i = 0; i < SIZEOF_HALF_DMA_BUFFER_IN_BYTES / 4; i++) {
for (uint8_t b = 0; b < sizeof(uint16_t); b++) {
ringbuf_pop(&self->ring_buffer, &dma_buffer_p[i * 4 + b]);
dma_buffer_p[i * 4 + b + 2] = dma_buffer_p[i * 4 + b]; // duplicated mono sample
}
}
} else if ((self->format == MONO) && (self->bits == 32)) {
for (uint32_t i = 0; i < SIZEOF_HALF_DMA_BUFFER_IN_BYTES / 8; i++) {
for (uint8_t b = 0; b < sizeof(uint32_t); b++) {
ringbuf_pop(&self->ring_buffer, &dma_buffer_p[i * 8 + b]);
dma_buffer_p[i * 8 + b + 4] = dma_buffer_p[i * 8 + b]; // duplicated mono sample
}
}
} else { // STEREO, both 16-bit and 32-bit
for (uint32_t i = 0; i < SIZEOF_HALF_DMA_BUFFER_IN_BYTES; i++) {
ringbuf_pop(&self->ring_buffer, &dma_buffer_p[i]);
}
}
// reformat 32 bit samples to match STM32 HAL API format
if (self->bits == 32) {
reformat_32_bit_samples((int32_t *)dma_buffer_p, SIZEOF_HALF_DMA_BUFFER_IN_BYTES / (sizeof(uint32_t)));
}
}
// flush cache to RAM so DMA can read the sample data
MP_HAL_CLEAN_DCACHE(dma_buffer_p, SIZEOF_HALF_DMA_BUFFER_IN_BYTES);
}
STATIC bool i2s_init(machine_i2s_obj_t *self) {
// init the GPIO lines
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
GPIO_InitStructure.Pull = GPIO_PULLUP;
if (self->i2s_id == 1) {
self->hi2s.Instance = I2S1;
__SPI1_CLK_ENABLE();
// configure DMA streams
if (self->mode == I2S_MODE_MASTER_RX) {
self->dma_descr_rx = &dma_I2S_1_RX;
} else {
self->dma_descr_tx = &dma_I2S_1_TX;
}
} else if (self->i2s_id == 2) {
self->hi2s.Instance = I2S2;
__SPI2_CLK_ENABLE();
// configure DMA streams
if (self->mode == I2S_MODE_MASTER_RX) {
self->dma_descr_rx = &dma_I2S_2_RX;
} else {
self->dma_descr_tx = &dma_I2S_2_TX;
}
} else {
// invalid id number; should not get here as i2s object should not
// have been created without setting a valid i2s instance number
return false;
}
// GPIO Pin initialization
if (self->sck != MP_OBJ_TO_PTR(MP_OBJ_NULL)) {
GPIO_InitStructure.Pin = self->sck->pin_mask;
const pin_af_obj_t *af = pin_find_af(self->sck, AF_FN_I2S, self->i2s_id);
GPIO_InitStructure.Alternate = (uint8_t)af->idx;
HAL_GPIO_Init(self->sck->gpio, &GPIO_InitStructure);
}
if (self->ws != MP_OBJ_TO_PTR(MP_OBJ_NULL)) {
GPIO_InitStructure.Pin = self->ws->pin_mask;
const pin_af_obj_t *af = pin_find_af(self->ws, AF_FN_I2S, self->i2s_id);
GPIO_InitStructure.Alternate = (uint8_t)af->idx;
HAL_GPIO_Init(self->ws->gpio, &GPIO_InitStructure);
}
if (self->sd != MP_OBJ_TO_PTR(MP_OBJ_NULL)) {
GPIO_InitStructure.Pin = self->sd->pin_mask;
const pin_af_obj_t *af = pin_find_af(self->sd, AF_FN_I2S, self->i2s_id);
GPIO_InitStructure.Alternate = (uint8_t)af->idx;
HAL_GPIO_Init(self->sd->gpio, &GPIO_InitStructure);
}
if (HAL_I2S_Init(&self->hi2s) == HAL_OK) {
// Reset and initialize Tx and Rx DMA channels
if (self->mode == I2S_MODE_MASTER_RX) {
dma_invalidate_channel(self->dma_descr_rx);
dma_init(&self->hdma_rx, self->dma_descr_rx, DMA_PERIPH_TO_MEMORY, &self->hi2s);
self->hi2s.hdmarx = &self->hdma_rx;
} else { // I2S_MODE_MASTER_TX
dma_invalidate_channel(self->dma_descr_tx);
dma_init(&self->hdma_tx, self->dma_descr_tx, DMA_MEMORY_TO_PERIPH, &self->hi2s);
self->hi2s.hdmatx = &self->hdma_tx;
}
__HAL_RCC_PLLI2S_ENABLE(); // start I2S clock
return true;
} else {
return false;
}
}
void HAL_I2S_ErrorCallback(I2S_HandleTypeDef *hi2s) {
uint32_t errorCode = HAL_I2S_GetError(hi2s);
printf("I2S Error = %ld\n", errorCode);
}
void HAL_I2S_RxCpltCallback(I2S_HandleTypeDef *hi2s) {
machine_i2s_obj_t *self;
if (hi2s->Instance == I2S1) {
self = machine_i2s_obj[0];
} else {
self = machine_i2s_obj[1];
}
// bottom half of buffer now filled,
// safe to empty the bottom half while the top half of buffer is being filled
empty_dma(self, BOTTOM_HALF);
// for non-blocking operation, this IRQ-based callback handles
// the readinto() method requests.
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
fill_appbuf_from_ringbuf_non_blocking(self);
}
}
void HAL_I2S_RxHalfCpltCallback(I2S_HandleTypeDef *hi2s) {
machine_i2s_obj_t *self;
if (hi2s->Instance == I2S1) {
self = machine_i2s_obj[0];
} else {
self = machine_i2s_obj[1];
}
// top half of buffer now filled,
// safe to empty the top half while the bottom half of buffer is being filled
empty_dma(self, TOP_HALF);
// for non-blocking operation, this IRQ-based callback handles
// the readinto() method requests.
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
fill_appbuf_from_ringbuf_non_blocking(self);
}
}
void HAL_I2S_TxCpltCallback(I2S_HandleTypeDef *hi2s) {
machine_i2s_obj_t *self;
if (hi2s->Instance == I2S1) {
self = machine_i2s_obj[0];
} else {
self = machine_i2s_obj[1];
}
// for non-blocking operation, this IRQ-based callback handles
// the write() method requests.
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
copy_appbuf_to_ringbuf_non_blocking(self);
}
// bottom half of buffer now emptied,
// safe to fill the bottom half while the top half of buffer is being emptied
feed_dma(self, BOTTOM_HALF);
}
void HAL_I2S_TxHalfCpltCallback(I2S_HandleTypeDef *hi2s) {
machine_i2s_obj_t *self;
if (hi2s->Instance == I2S1) {
self = machine_i2s_obj[0];
} else {
self = machine_i2s_obj[1];
}
// for non-blocking operation, this IRQ-based callback handles
// the write() method requests.
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
copy_appbuf_to_ringbuf_non_blocking(self);
}
// top half of buffer now emptied,
// safe to fill the top half while the bottom half of buffer is being emptied
feed_dma(self, TOP_HALF);
}
STATIC void machine_i2s_init_helper(machine_i2s_obj_t *self, size_t n_pos_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum {
ARG_sck,
ARG_ws,
ARG_sd,
ARG_mode,
ARG_bits,
ARG_format,
ARG_rate,
ARG_ibuf,
};
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_sck, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_ws, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_sd, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_mode, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_format, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_rate, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_ibuf, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = -1} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_pos_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
memset(&self->hi2s, 0, sizeof(self->hi2s));
//
// ---- Check validity of arguments ----
//
// are I2S pin assignments valid?
const pin_af_obj_t *pin_af;
// is SCK valid?
if (mp_obj_is_type(args[ARG_sck].u_obj, &pin_type)) {
pin_af = pin_find_af(MP_OBJ_TO_PTR(args[ARG_sck].u_obj), AF_FN_I2S, self->i2s_id);
if (pin_af->type != AF_PIN_TYPE_I2S_CK) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid SCK pin"));
}
} else {
mp_raise_ValueError(MP_ERROR_TEXT("SCK not a Pin type"));
}
// is WS valid?
if (mp_obj_is_type(args[ARG_ws].u_obj, &pin_type)) {
pin_af = pin_find_af(MP_OBJ_TO_PTR(args[ARG_ws].u_obj), AF_FN_I2S, self->i2s_id);
if (pin_af->type != AF_PIN_TYPE_I2S_WS) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid WS pin"));
}
} else {
mp_raise_ValueError(MP_ERROR_TEXT("WS not a Pin type"));
}
// is SD valid?
if (mp_obj_is_type(args[ARG_sd].u_obj, &pin_type)) {
pin_af = pin_find_af(MP_OBJ_TO_PTR(args[ARG_sd].u_obj), AF_FN_I2S, self->i2s_id);
if (pin_af->type != AF_PIN_TYPE_I2S_SD) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid SD pin"));
}
} else {
mp_raise_ValueError(MP_ERROR_TEXT("SD not a Pin type"));
}
// is Mode valid?
uint16_t i2s_mode = args[ARG_mode].u_int;
if ((i2s_mode != (I2S_MODE_MASTER_RX)) &&
(i2s_mode != (I2S_MODE_MASTER_TX))) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid mode"));
}
// is Bits valid?
int8_t i2s_bits = args[ARG_bits].u_int;
if ((i2s_bits != 16) &&
(i2s_bits != 32)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid bits"));
}
// is Format valid?
format_t i2s_format = args[ARG_format].u_int;
if ((i2s_format != MONO) &&
(i2s_format != STEREO)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid format"));
}
// is Rate valid?
// Not checked
// is Ibuf valid?
int32_t ring_buffer_len = args[ARG_ibuf].u_int;
if (ring_buffer_len > 0) {
uint8_t *buffer = m_new(uint8_t, ring_buffer_len);
self->ring_buffer_storage = buffer;
ringbuf_init(&self->ring_buffer, buffer, ring_buffer_len);
} else {
mp_raise_ValueError(MP_ERROR_TEXT("invalid ibuf"));
}
self->sck = MP_OBJ_TO_PTR(args[ARG_sck].u_obj);
self->ws = MP_OBJ_TO_PTR(args[ARG_ws].u_obj);
self->sd = MP_OBJ_TO_PTR(args[ARG_sd].u_obj);
self->mode = i2s_mode;
self->bits = i2s_bits;
self->format = i2s_format;
self->rate = args[ARG_rate].u_int;
self->ibuf = ring_buffer_len;
self->callback_for_non_blocking = MP_OBJ_NULL;
self->non_blocking_descriptor.copy_in_progress = false;
self->io_mode = BLOCKING;
I2S_InitTypeDef *init = &self->hi2s.Init;
init->Mode = i2s_mode;
init->Standard = I2S_STANDARD_PHILIPS;
init->DataFormat = get_dma_bits(self->mode, self->bits);
init->MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
init->AudioFreq = args[ARG_rate].u_int;
init->CPOL = I2S_CPOL_LOW;
init->ClockSource = I2S_CLOCK_PLL;
// init the I2S bus
if (!i2s_init(self)) {
mp_raise_msg_varg(&mp_type_OSError, MP_ERROR_TEXT("I2S init failed"));
}
// start DMA. DMA is configured to run continuously, using a circular buffer configuration
uint32_t number_of_samples = 0;
if (init->DataFormat == I2S_DATAFORMAT_16B) {
number_of_samples = SIZEOF_DMA_BUFFER_IN_BYTES / sizeof(uint16_t);
} else { // 32 bits
number_of_samples = SIZEOF_DMA_BUFFER_IN_BYTES / sizeof(uint32_t);
}
HAL_StatusTypeDef status;
if (self->mode == I2S_MODE_MASTER_TX) {
status = HAL_I2S_Transmit_DMA(&self->hi2s, (void *)self->dma_buffer_dcache_aligned, number_of_samples);
} else { // RX
status = HAL_I2S_Receive_DMA(&self->hi2s, (void *)self->dma_buffer_dcache_aligned, number_of_samples);
}
if (status != HAL_OK) {
mp_raise_msg_varg(&mp_type_OSError, MP_ERROR_TEXT("DMA init failed"));
}
}
STATIC void machine_i2s_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "I2S(id=%u,\n"
"sck="MP_HAL_PIN_FMT ",\n"
"ws="MP_HAL_PIN_FMT ",\n"
"sd="MP_HAL_PIN_FMT ",\n"
"mode=%u,\n"
"bits=%u, format=%u,\n"
"rate=%d, ibuf=%d)",
self->i2s_id,
mp_hal_pin_name(self->sck),
mp_hal_pin_name(self->ws),
mp_hal_pin_name(self->sd),
self->mode,
self->bits, self->format,
self->rate, self->ibuf
);
}
STATIC mp_obj_t machine_i2s_make_new(const mp_obj_type_t *type, size_t n_pos_args, size_t n_kw_args, const mp_obj_t *args) {
mp_arg_check_num(n_pos_args, n_kw_args, 1, MP_OBJ_FUN_ARGS_MAX, true);
uint8_t i2s_id = mp_obj_get_int(args[0]);
uint8_t i2s_id_zero_base = 0;
if (0) {
#ifdef MICROPY_HW_I2S1
} else if (i2s_id == 1) {
i2s_id_zero_base = 0;
#endif
#ifdef MICROPY_HW_I2S2
} else if (i2s_id == 2) {
i2s_id_zero_base = 1;
#endif
} else {
mp_raise_ValueError(MP_ERROR_TEXT("invalid id"));
}
machine_i2s_obj_t *self;
if (machine_i2s_obj[i2s_id_zero_base] == NULL) {
self = m_new_obj(machine_i2s_obj_t);
machine_i2s_obj[i2s_id_zero_base] = self;
self->base.type = &machine_i2s_type;
self->i2s_id = i2s_id;
} else {
self = machine_i2s_obj[i2s_id_zero_base];
machine_i2s_deinit(MP_OBJ_FROM_PTR(self));
}
// align DMA buffer start to the cache line size (32 bytes)
self->dma_buffer_dcache_aligned = (uint8_t *)((uint32_t)(self->dma_buffer + 0x1f) & ~0x1f);
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw_args, args + n_pos_args);
machine_i2s_init_helper(self, n_pos_args - 1, args + 1, &kw_args);
return MP_OBJ_FROM_PTR(self);
}
STATIC mp_obj_t machine_i2s_init(size_t n_pos_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
machine_i2s_deinit(MP_OBJ_FROM_PTR(self));
machine_i2s_init_helper(self, n_pos_args - 1, pos_args + 1, kw_args);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2s_init_obj, 1, machine_i2s_init);
STATIC mp_obj_t machine_i2s_deinit(mp_obj_t self_in) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
dma_deinit(self->dma_descr_tx);
dma_deinit(self->dma_descr_rx);
HAL_I2S_DeInit(&self->hi2s);
if (self->hi2s.Instance == I2S1) {
__SPI1_FORCE_RESET();
__SPI1_RELEASE_RESET();
__SPI1_CLK_DISABLE();
} else if (self->hi2s.Instance == I2S2) {
__SPI2_FORCE_RESET();
__SPI2_RELEASE_RESET();
__SPI2_CLK_DISABLE();
}
m_free(self->ring_buffer_storage);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_i2s_deinit_obj, machine_i2s_deinit);
STATIC mp_obj_t machine_i2s_irq(mp_obj_t self_in, mp_obj_t handler) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (handler != mp_const_none && !mp_obj_is_callable(handler)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid callback"));
}
if (handler != mp_const_none) {
self->io_mode = NON_BLOCKING;
} else {
self->io_mode = BLOCKING;
}
self->callback_for_non_blocking = handler;
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(machine_i2s_irq_obj, machine_i2s_irq);
// Shift() is typically used as a volume control.
// shift=1 increases volume by 6dB, shift=-1 decreases volume by 6dB
STATIC mp_obj_t machine_i2s_shift(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_buf, ARG_bits, ARG_shift};
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_bits, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_shift, MP_ARG_REQUIRED | MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
};
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_RW);
int16_t *buf_16 = bufinfo.buf;
int32_t *buf_32 = bufinfo.buf;
uint8_t bits = args[ARG_bits].u_int;
int8_t shift = args[ARG_shift].u_int;
uint32_t num_audio_samples;
switch (bits) {
case 16:
num_audio_samples = bufinfo.len / sizeof(uint16_t);
break;
case 32:
num_audio_samples = bufinfo.len / sizeof(uint32_t);
break;
default:
mp_raise_ValueError(MP_ERROR_TEXT("invalid bits"));
break;
}
for (uint32_t i = 0; i < num_audio_samples; i++) {
switch (bits) {
case 16:
if (shift >= 0) {
buf_16[i] = buf_16[i] << shift;
} else {
buf_16[i] = buf_16[i] >> abs(shift);
}
break;
case 32:
if (shift >= 0) {
buf_32[i] = buf_32[i] << shift;
} else {
buf_32[i] = buf_32[i] >> abs(shift);
}
break;
}
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2s_shift_fun_obj, 0, machine_i2s_shift);
STATIC MP_DEFINE_CONST_STATICMETHOD_OBJ(machine_i2s_shift_obj, MP_ROM_PTR(&machine_i2s_shift_fun_obj));
STATIC const mp_rom_map_elem_t machine_i2s_locals_dict_table[] = {
// Methods
{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&machine_i2s_init_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&machine_i2s_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_irq), MP_ROM_PTR(&machine_i2s_irq_obj) },
// Static method
{ MP_ROM_QSTR(MP_QSTR_shift), MP_ROM_PTR(&machine_i2s_shift_obj) },
// Constants
{ MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_INT(I2S_MODE_MASTER_RX) },
{ MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_INT(I2S_MODE_MASTER_TX) },
{ MP_ROM_QSTR(MP_QSTR_STEREO), MP_ROM_INT(STEREO) },
{ MP_ROM_QSTR(MP_QSTR_MONO), MP_ROM_INT(MONO) },
};
MP_DEFINE_CONST_DICT(machine_i2s_locals_dict, machine_i2s_locals_dict_table);
STATIC mp_uint_t machine_i2s_stream_read(mp_obj_t self_in, void *buf_in, mp_uint_t size, int *errcode) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (self->mode != I2S_MODE_MASTER_RX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
uint8_t appbuf_sample_size_in_bytes = (self->bits / 8) * (self->format == STEREO ? 2: 1);
if (size % appbuf_sample_size_in_bytes != 0) {
*errcode = MP_EINVAL;
return MP_STREAM_ERROR;
}
if (size == 0) {
return 0;
}
if (self->io_mode == NON_BLOCKING) {
self->non_blocking_descriptor.appbuf.buf = (void *)buf_in;
self->non_blocking_descriptor.appbuf.len = size;
self->non_blocking_descriptor.index = 0;
self->non_blocking_descriptor.copy_in_progress = true;
return size;
} else { // blocking or uasyncio mode
mp_buffer_info_t appbuf;
appbuf.buf = (void *)buf_in;
appbuf.len = size;
uint32_t num_bytes_read = fill_appbuf_from_ringbuf(self, &appbuf);
return num_bytes_read;
}
}
STATIC mp_uint_t machine_i2s_stream_write(mp_obj_t self_in, const void *buf_in, mp_uint_t size, int *errcode) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
if (self->mode != I2S_MODE_MASTER_TX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
if (size == 0) {
return 0;
}
if (self->io_mode == NON_BLOCKING) {
self->non_blocking_descriptor.appbuf.buf = (void *)buf_in;
self->non_blocking_descriptor.appbuf.len = size;
self->non_blocking_descriptor.index = 0;
self->non_blocking_descriptor.copy_in_progress = true;
return size;
} else { // blocking or uasyncio mode
mp_buffer_info_t appbuf;
appbuf.buf = (void *)buf_in;
appbuf.len = size;
uint32_t num_bytes_written = copy_appbuf_to_ringbuf(self, &appbuf);
return num_bytes_written;
}
}
STATIC mp_uint_t machine_i2s_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *errcode) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_uint_t ret;
uintptr_t flags = arg;
self->io_mode = UASYNCIO; // a call to ioctl() is an indication that uasyncio is being used
if (request == MP_STREAM_POLL) {
ret = 0;
if (flags & MP_STREAM_POLL_RD) {
if (self->mode != I2S_MODE_MASTER_RX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
if (!ringbuf_is_empty(&self->ring_buffer)) {
ret |= MP_STREAM_POLL_RD;
}
}
if (flags & MP_STREAM_POLL_WR) {
if (self->mode != I2S_MODE_MASTER_TX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
if (!ringbuf_is_full(&self->ring_buffer)) {
ret |= MP_STREAM_POLL_WR;
}
}
} else {
*errcode = MP_EINVAL;
ret = MP_STREAM_ERROR;
}
return ret;
}
STATIC const mp_stream_p_t i2s_stream_p = {
.read = machine_i2s_stream_read,
.write = machine_i2s_stream_write,
.ioctl = machine_i2s_ioctl,
.is_text = false,
};
const mp_obj_type_t machine_i2s_type = {
{ &mp_type_type },
.name = MP_QSTR_I2S,
.print = machine_i2s_print,
.getiter = mp_identity_getiter,
.iternext = mp_stream_unbuffered_iter,
.protocol = &i2s_stream_p,
.make_new = machine_i2s_make_new,
.locals_dict = (mp_obj_dict_t *)&machine_i2s_locals_dict,
};
#endif // MICROPY_HW_ENABLE_I2S
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