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micropython/extmod/machine_i2s.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Mike Teachman
* Copyright (c) 2023 Damien P. George
*
* 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 "py/runtime.h"
#include "py/stream.h"
#if MICROPY_PY_MACHINE_I2S
#include "extmod/modmachine.h"
// The I2S class 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
// - implementation of asynchronous background operations is port specific
//
// Mode3: Asyncio
// - implements the stream protocol
// - asyncio 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)
#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,
ASYNCIO
} io_mode_t;
// Arguments for I2S() constructor and I2S.init().
enum {
ARG_sck,
ARG_ws,
ARG_sd,
#if MICROPY_PY_MACHINE_I2S_MCK
ARG_mck,
#endif
ARG_mode,
ARG_bits,
ARG_format,
ARG_rate,
ARG_ibuf,
};
#if MICROPY_PY_MACHINE_I2S_RING_BUF
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;
STATIC void ringbuf_init(ring_buf_t *rbuf, uint8_t *buffer, size_t size);
STATIC bool ringbuf_push(ring_buf_t *rbuf, uint8_t data);
STATIC bool ringbuf_pop(ring_buf_t *rbuf, uint8_t *data);
STATIC size_t ringbuf_available_data(ring_buf_t *rbuf);
STATIC size_t ringbuf_available_space(ring_buf_t *rbuf);
STATIC void fill_appbuf_from_ringbuf_non_blocking(machine_i2s_obj_t *self);
STATIC void copy_appbuf_to_ringbuf_non_blocking(machine_i2s_obj_t *self);
#endif // MICROPY_PY_MACHINE_I2S_RING_BUF
// The port must provide implementations of these low-level I2S functions.
STATIC void mp_machine_i2s_init_helper(machine_i2s_obj_t *self, mp_arg_val_t *args);
STATIC machine_i2s_obj_t *mp_machine_i2s_make_new_instance(mp_int_t i2s_id);
STATIC void mp_machine_i2s_deinit(machine_i2s_obj_t *self);
STATIC void mp_machine_i2s_irq_update(machine_i2s_obj_t *self);
// The port provides implementations of the above in this file.
#include MICROPY_PY_MACHINE_I2S_INCLUDEFILE
#if MICROPY_PY_MACHINE_I2S_RING_BUF
// 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;
}
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 asyncio 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 == ASYNCIO) {
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 == ASYNCIO) {
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 asyncio 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 == ASYNCIO) {
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));
}
}
}
#endif // MICROPY_PY_MACHINE_I2S_RING_BUF
MP_NOINLINE 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) {
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} },
#if MICROPY_PY_MACHINE_I2S_MCK
{ MP_QSTR_mck, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
#endif
{ 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);
mp_machine_i2s_init_helper(self, args);
}
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"
#if MICROPY_PY_MACHINE_I2S_MCK
"mck="MP_HAL_PIN_FMT ",\n"
#endif
"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),
#if MICROPY_PY_MACHINE_I2S_MCK
mp_hal_pin_name(self->mck),
#endif
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);
mp_int_t i2s_id = mp_obj_get_int(args[0]);
machine_i2s_obj_t *self = mp_machine_i2s_make_new_instance(i2s_id);
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);
}
// I2S.init(...)
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]);
mp_machine_i2s_deinit(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);
// I2S.deinit()
STATIC mp_obj_t machine_i2s_deinit(mp_obj_t self_in) {
machine_i2s_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_machine_i2s_deinit(self);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(machine_i2s_deinit_obj, machine_i2s_deinit);
// I2S.irq(handler)
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;
mp_machine_i2s_irq_update(self);
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) },
#if MICROPY_PY_MACHINE_I2S_FINALISER
{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&machine_i2s_deinit_obj) },
#endif
// 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(MICROPY_PY_MACHINE_I2S_CONSTANT_RX) },
{ MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_INT(MICROPY_PY_MACHINE_I2S_CONSTANT_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 != MICROPY_PY_MACHINE_I2S_CONSTANT_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) {
#if MICROPY_PY_MACHINE_I2S_RING_BUF
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;
#else
non_blocking_descriptor_t descriptor;
descriptor.appbuf.buf = (void *)buf_in;
descriptor.appbuf.len = size;
descriptor.callback = self->callback_for_non_blocking;
descriptor.direction = I2S_RX_TRANSFER;
// send the descriptor to the task that handles non-blocking mode
xQueueSend(self->non_blocking_mode_queue, &descriptor, 0);
#endif
return size;
} else { // blocking or asyncio mode
mp_buffer_info_t appbuf;
appbuf.buf = (void *)buf_in;
appbuf.len = size;
#if MICROPY_PY_MACHINE_I2S_RING_BUF
uint32_t num_bytes_read = fill_appbuf_from_ringbuf(self, &appbuf);
#else
uint32_t num_bytes_read = fill_appbuf_from_dma(self, &appbuf);
#endif
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 != MICROPY_PY_MACHINE_I2S_CONSTANT_TX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
if (size == 0) {
return 0;
}
if (self->io_mode == NON_BLOCKING) {
#if MICROPY_PY_MACHINE_I2S_RING_BUF
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;
#else
non_blocking_descriptor_t descriptor;
descriptor.appbuf.buf = (void *)buf_in;
descriptor.appbuf.len = size;
descriptor.callback = self->callback_for_non_blocking;
descriptor.direction = I2S_TX_TRANSFER;
// send the descriptor to the task that handles non-blocking mode
xQueueSend(self->non_blocking_mode_queue, &descriptor, 0);
#endif
return size;
} else { // blocking or asyncio mode
mp_buffer_info_t appbuf;
appbuf.buf = (void *)buf_in;
appbuf.len = size;
#if MICROPY_PY_MACHINE_I2S_RING_BUF
uint32_t num_bytes_written = copy_appbuf_to_ringbuf(self, &appbuf);
#else
uint32_t num_bytes_written = copy_appbuf_to_dma(self, &appbuf);
#endif
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 = ASYNCIO; // a call to ioctl() is an indication that asyncio is being used
if (request == MP_STREAM_POLL) {
ret = 0;
if (flags & MP_STREAM_POLL_RD) {
if (self->mode != MICROPY_PY_MACHINE_I2S_CONSTANT_RX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
#if MICROPY_PY_MACHINE_I2S_RING_BUF
if (!ringbuf_is_empty(&self->ring_buffer)) {
ret |= MP_STREAM_POLL_RD;
}
#else
// check event queue to determine if a DMA buffer has been filled
// (which is an indication that at least one DMA buffer is available to be read)
// note: timeout = 0 so the call is non-blocking
i2s_event_t i2s_event;
if (xQueueReceive(self->i2s_event_queue, &i2s_event, 0)) {
if (i2s_event.type == I2S_EVENT_RX_DONE) {
// getting here means that at least one DMA buffer is now full
// indicating that audio samples can be read from the I2S object
ret |= MP_STREAM_POLL_RD;
}
}
#endif
}
if (flags & MP_STREAM_POLL_WR) {
if (self->mode != MICROPY_PY_MACHINE_I2S_CONSTANT_TX) {
*errcode = MP_EPERM;
return MP_STREAM_ERROR;
}
#if MICROPY_PY_MACHINE_I2S_RING_BUF
if (!ringbuf_is_full(&self->ring_buffer)) {
ret |= MP_STREAM_POLL_WR;
}
#else
// check event queue to determine if a DMA buffer has been emptied
// (which is an indication that at least one DMA buffer is available to be written)
// note: timeout = 0 so the call is non-blocking
i2s_event_t i2s_event;
if (xQueueReceive(self->i2s_event_queue, &i2s_event, 0)) {
if (i2s_event.type == I2S_EVENT_TX_DONE) {
// getting here means that at least one DMA buffer is now empty
// indicating that audio samples can be written to the I2S object
ret |= MP_STREAM_POLL_WR;
}
}
#endif
}
} 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,
};
MP_DEFINE_CONST_OBJ_TYPE(
machine_i2s_type,
MP_QSTR_I2S,
MP_TYPE_FLAG_ITER_IS_STREAM,
make_new, machine_i2s_make_new,
print, machine_i2s_print,
protocol, &i2s_stream_p,
locals_dict, &machine_i2s_locals_dict
);
#endif // MICROPY_PY_MACHINE_I2S
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