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micropython/ports/mimxrt/machine_i2s.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2022 Mike Teachman
* Copyright (c) 2022 Robert Hammelrath
*
* 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.
*/
// This file is never compiled standalone, it's included directly from
// extmod/machine_i2s.c via MICROPY_PY_MACHINE_I2S_INCLUDEFILE.
#include "py/mphal.h"
#include "dma_manager.h"
#include CLOCK_CONFIG_H
#include "fsl_iomuxc.h"
#include "fsl_dmamux.h"
#include "fsl_edma.h"
#include "fsl_sai.h"
// Notes on this port's specific implementation of I2S:
// - the DMA callback is used to implement the asynchronous background operations, for non-blocking mode
// - all 3 Modes of operation are implemented using the peripheral drivers in the NXP MCUXpresso SDK
// - all sample data transfers use DMA
// - 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.
// - master clock frequency is sampling frequency * 256
// 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 SAI_CHANNEL_0 (0)
#define SAI_NUM_AUDIO_CHANNELS (2U)
typedef enum {
SCK,
WS,
SD,
MCK
} i2s_pin_function_t;
typedef enum {
RX,
TX,
} i2s_mode_t;
typedef enum {
TOP_HALF,
BOTTOM_HALF
} ping_pong_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;
mp_hal_pin_obj_t mck;
i2s_mode_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_Type *i2s_inst;
int dma_channel;
edma_handle_t edmaHandle;
edma_tcd_t *edmaTcd;
} machine_i2s_obj_t;
typedef struct _iomux_table_t {
uint32_t muxRegister;
uint32_t muxMode;
uint32_t inputRegister;
uint32_t inputDaisy;
uint32_t configRegister;
} iomux_table_t;
typedef struct _gpio_map_t {
uint8_t hw_id;
i2s_pin_function_t fn;
i2s_mode_t mode;
qstr name;
iomux_table_t iomux;
} gpio_map_t;
typedef struct _i2s_clock_config_t {
sai_sample_rate_t rate;
const clock_audio_pll_config_t *pll_config;
uint32_t clock_pre_divider;
uint32_t clock_divider;
} i2s_clock_config_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] = {
{-1, -1, 0, 1, -1, -1, -1, -1 }, // Mono, 16-bits
{ 0, 1, 2, 3, -1, -1, -1, -1 }, // Mono, 32-bits
{-1, -1, 0, 1, -1, -1, 2, 3 }, // Stereo, 16-bits
{ 0, 1, 2, 3, 4, 5, 6, 7 }, // Stereo, 32-bits
};
// 2 PLL configurations
// PLL output frequency = 24MHz * (.loopDivider + .numerator/.denominator)
// Configuration 1: for sampling frequencies [Hz]: 8000, 12000, 16000, 24000, 32000, 48000
// Clock frequency = 786,432,000 Hz = 48000 * 64 * 256
STATIC const clock_audio_pll_config_t audioPllConfig_8000_48000 = {
.loopDivider = 32, // PLL loop divider. Valid range for DIV_SELECT divider value: 27~54
.postDivider = 1, // Divider after the PLL, should only be 1, 2, 4, 8, 16
.numerator = 76800, // 30 bit numerator of fractional loop divider
.denominator = 100000, // 30 bit denominator of fractional loop divider
#if !defined(MIMXRT117x_SERIES)
.src = kCLOCK_PllClkSrc24M // Pll clock source
#endif
};
// Configuration 2: for sampling frequencies [Hz]: 11025, 22050, 44100
// Clock frequency = 722,534,400 = 44100 * 64 * 256
STATIC const clock_audio_pll_config_t audioPllConfig_11025_44100 = {
.loopDivider = 30, // PLL loop divider. Valid range for DIV_SELECT divider value: 27~54
.postDivider = 1, // Divider after the PLL, should only be 1, 2, 4, 8, 16
.numerator = 10560, // 30 bit numerator of fractional loop divider
.denominator = 100000, // 30 bit denominator of fractional loop divider
#if !defined(MIMXRT117x_SERIES)
.src = kCLOCK_PllClkSrc24M // Pll clock source
#endif
};
#if defined(MIMXRT117x_SERIES)
// for 1176 the pre_div value is used for post_div of the Audio PLL,
// which is 2**n: 0->1, 1->2, 2->4, 3->8, 4->16, 5->32
// The divider is 8 bit and must be given as n (not n-1)
// So the total division factor is given by (2**p) * d
STATIC const i2s_clock_config_t clock_config_map[] = {
{kSAI_SampleRate8KHz, &audioPllConfig_8000_48000, 1, 192}, // 384
{kSAI_SampleRate11025Hz, &audioPllConfig_11025_44100, 1, 128}, // 256
{kSAI_SampleRate12KHz, &audioPllConfig_8000_48000, 1, 128}, // 256
{kSAI_SampleRate16KHz, &audioPllConfig_8000_48000, 0, 192}, // 192
{kSAI_SampleRate22050Hz, &audioPllConfig_11025_44100, 0, 128}, // 128
{kSAI_SampleRate24KHz, &audioPllConfig_8000_48000, 0, 128}, // 128
{kSAI_SampleRate32KHz, &audioPllConfig_8000_48000, 0, 96}, // 96
{kSAI_SampleRate44100Hz, &audioPllConfig_11025_44100, 0, 64}, // 64
{kSAI_SampleRate48KHz, &audioPllConfig_8000_48000, 0, 64} // 64
};
STATIC const clock_root_t i2s_clock_mux[] = I2S_CLOCK_MUX;
#else
// for 10xx the total division factor is given by (p + 1) * (d + 1)
STATIC const i2s_clock_config_t clock_config_map[] = {
{kSAI_SampleRate8KHz, &audioPllConfig_8000_48000, 5, 63}, // 384
{kSAI_SampleRate11025Hz, &audioPllConfig_11025_44100, 3, 63}, // 256
{kSAI_SampleRate12KHz, &audioPllConfig_8000_48000, 3, 63}, // 256
{kSAI_SampleRate16KHz, &audioPllConfig_8000_48000, 2, 63}, // 192
{kSAI_SampleRate22050Hz, &audioPllConfig_11025_44100, 1, 63}, // 128
{kSAI_SampleRate24KHz, &audioPllConfig_8000_48000, 1, 63}, // 128
{kSAI_SampleRate32KHz, &audioPllConfig_8000_48000, 1, 47}, // 96
{kSAI_SampleRate44100Hz, &audioPllConfig_11025_44100, 0, 63}, // 64
{kSAI_SampleRate48KHz, &audioPllConfig_8000_48000, 0, 63} // 64
};
STATIC const clock_mux_t i2s_clock_mux[] = I2S_CLOCK_MUX;
STATIC const clock_div_t i2s_clock_pre_div[] = I2S_CLOCK_PRE_DIV;
STATIC const clock_div_t i2s_clock_div[] = I2S_CLOCK_DIV;
STATIC const iomuxc_gpr_mode_t i2s_iomuxc_gpr_mode[] = I2S_IOMUXC_GPR_MODE;
#endif
STATIC const I2S_Type *i2s_base_ptr[] = I2S_BASE_PTRS;
STATIC const dma_request_source_t i2s_dma_req_src_tx[] = I2S_DMA_REQ_SRC_TX;
STATIC const dma_request_source_t i2s_dma_req_src_rx[] = I2S_DMA_REQ_SRC_RX;
STATIC const gpio_map_t i2s_gpio_map[] = I2S_GPIO_MAP;
AT_NONCACHEABLE_SECTION_ALIGN(STATIC edma_tcd_t edmaTcd[MICROPY_HW_I2S_NUM], 32);
// called on processor reset
void machine_i2s_init0() {
for (uint8_t i = 0; i < MICROPY_HW_I2S_NUM; i++) {
MP_STATE_PORT(machine_i2s_obj)[i] = NULL;
}
}
// called on soft reboot
void machine_i2s_deinit_all(void) {
for (uint8_t i = 0; i < MICROPY_HW_I2S_NUM; i++) {
machine_i2s_obj_t *i2s_obj = MP_STATE_PORT(machine_i2s_obj)[i];
if (i2s_obj != NULL) {
machine_i2s_deinit(i2s_obj);
MP_STATE_PORT(machine_i2s_obj)[i] = NULL;
}
}
}
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 == TX) {
if (bits == 16) {
return 16;
} else {
return 32;
}
return bits;
} else { // RX
// always read 32 bit words for I2S e.g. I2S MEMS microphones
return 32;
}
}
STATIC bool lookup_gpio(const machine_pin_obj_t *pin, i2s_pin_function_t fn, uint8_t hw_id, uint16_t *index) {
for (uint16_t i = 0; i < ARRAY_SIZE(i2s_gpio_map); i++) {
if ((pin->name == i2s_gpio_map[i].name) &&
(i2s_gpio_map[i].fn == fn) &&
(i2s_gpio_map[i].hw_id == hw_id)) {
*index = i;
return true;
}
}
return false;
}
STATIC bool set_iomux(const machine_pin_obj_t *pin, i2s_pin_function_t fn, uint8_t hw_id) {
uint16_t mapping_index;
if (lookup_gpio(pin, fn, hw_id, &mapping_index)) {
iomux_table_t iom = i2s_gpio_map[mapping_index].iomux;
IOMUXC_SetPinMux(iom.muxRegister, iom.muxMode, iom.inputRegister, iom.inputDaisy, iom.configRegister, 1U);
IOMUXC_SetPinConfig(iom.muxRegister, iom.muxMode, iom.inputRegister, iom.inputDaisy, iom.configRegister,
pin_generate_config(PIN_PULL_DISABLED, PIN_MODE_OUT, 2, iom.configRegister));
return true;
} else {
return false;
}
}
STATIC bool is_rate_supported(int32_t rate) {
for (uint16_t i = 0; i < ARRAY_SIZE(clock_config_map); i++) {
if (clock_config_map[i].rate == rate) {
return true;
}
}
return false;
}
STATIC const clock_audio_pll_config_t *get_pll_config(int32_t rate) {
for (uint16_t i = 0; i < ARRAY_SIZE(clock_config_map); i++) {
if (clock_config_map[i].rate == rate) {
return clock_config_map[i].pll_config;
}
}
return 0;
}
STATIC const uint32_t get_clock_pre_divider(int32_t rate) {
for (uint16_t i = 0; i < ARRAY_SIZE(clock_config_map); i++) {
if (clock_config_map[i].rate == rate) {
return clock_config_map[i].clock_pre_divider;
}
}
return 0;
}
STATIC const uint32_t get_clock_divider(int32_t rate) {
for (uint16_t i = 0; i < ARRAY_SIZE(clock_config_map); i++) {
if (clock_config_map[i].rate == rate) {
return clock_config_map[i].clock_divider;
}
}
return 0;
}
// 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.
// 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]);
}
}
} else {
// underflow. clear buffer to transmit "silence" on the I2S bus
memset(dma_buffer_p, 0, SIZEOF_HALF_DMA_BUFFER_IN_BYTES);
}
// 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 void edma_i2s_callback(edma_handle_t *handle, void *userData, bool transferDone, uint32_t tcds) {
machine_i2s_obj_t *self = userData;
if (self->mode == TX) {
// for non-blocking mode, sample copying (appbuf->ibuf) is initiated in this callback routine
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
copy_appbuf_to_ringbuf_non_blocking(self);
}
if (transferDone) {
// 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);
} else {
// 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);
}
} else { // RX
if (transferDone) {
// 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);
} else {
// 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 mode, sample copying (ibuf->appbuf) is initiated in this callback routine
if ((self->io_mode == NON_BLOCKING) && (self->non_blocking_descriptor.copy_in_progress)) {
fill_appbuf_from_ringbuf_non_blocking(self);
}
}
}
STATIC bool i2s_init(machine_i2s_obj_t *self) {
#if defined(MIMXRT117x_SERIES)
clock_audio_pll_config_t pll_config = *get_pll_config(self->rate);
pll_config.postDivider = get_clock_pre_divider(self->rate);
CLOCK_InitAudioPll(&pll_config);
CLOCK_SetRootClockMux(i2s_clock_mux[self->i2s_id], I2S_AUDIO_PLL_CLOCK);
CLOCK_SetRootClockDiv(i2s_clock_mux[self->i2s_id], get_clock_divider(self->rate));
uint32_t clock_freq = CLOCK_GetFreq(kCLOCK_AudioPllOut) / get_clock_divider(self->rate);
#else
CLOCK_InitAudioPll(get_pll_config(self->rate));
CLOCK_SetMux(i2s_clock_mux[self->i2s_id], I2S_AUDIO_PLL_CLOCK);
CLOCK_SetDiv(i2s_clock_pre_div[self->i2s_id], get_clock_pre_divider(self->rate));
CLOCK_SetDiv(i2s_clock_div[self->i2s_id], get_clock_divider(self->rate));
uint32_t clock_freq =
(CLOCK_GetFreq(kCLOCK_AudioPllClk) / (get_clock_divider(self->rate) + 1U) /
(get_clock_pre_divider(self->rate) + 1U));
#endif
if (!set_iomux(self->sck, SCK, self->i2s_id)) {
return false;
}
if (!set_iomux(self->ws, WS, self->i2s_id)) {
return false;
}
if (!set_iomux(self->sd, SD, self->i2s_id)) {
return false;
}
if (self->mck) {
if (!set_iomux(self->mck, MCK, self->i2s_id)) {
return false;
}
#if defined(MIMXRT117x_SERIES)
switch (self->i2s_id) {
case 1:
IOMUXC_GPR->GPR0 |= IOMUXC_GPR_GPR0_SAI1_MCLK_DIR_MASK;
break;
case 2:
IOMUXC_GPR->GPR1 |= IOMUXC_GPR_GPR1_SAI2_MCLK_DIR_MASK;
break;
case 3:
IOMUXC_GPR->GPR2 |= IOMUXC_GPR_GPR2_SAI3_MCLK_DIR_MASK;
break;
case 4:
IOMUXC_GPR->GPR2 |= IOMUXC_GPR_GPR2_SAI4_MCLK_DIR_MASK;
break;
}
#else
IOMUXC_EnableMode(IOMUXC_GPR, i2s_iomuxc_gpr_mode[self->i2s_id], true);
#endif
}
self->dma_channel = allocate_dma_channel();
DMAMUX_Init(DMAMUX);
if (self->mode == TX) {
DMAMUX_SetSource(DMAMUX, self->dma_channel, i2s_dma_req_src_tx[self->i2s_id]);
} else { // RX
DMAMUX_SetSource(DMAMUX, self->dma_channel, i2s_dma_req_src_rx[self->i2s_id]);
}
DMAMUX_EnableChannel(DMAMUX, self->dma_channel);
dma_init();
EDMA_CreateHandle(&self->edmaHandle, DMA0, self->dma_channel);
EDMA_SetCallback(&self->edmaHandle, edma_i2s_callback, self);
EDMA_ResetChannel(DMA0, self->dma_channel);
SAI_Init(self->i2s_inst);
sai_transceiver_t saiConfig;
SAI_GetClassicI2SConfig(&saiConfig, get_dma_bits(self->mode, self->bits), kSAI_Stereo, kSAI_Channel0Mask);
saiConfig.masterSlave = kSAI_Master;
uint16_t sck_index;
lookup_gpio(self->sck, SCK, self->i2s_id, &sck_index);
if ((self->mode == TX) && (i2s_gpio_map[sck_index].mode == TX)) {
saiConfig.syncMode = kSAI_ModeAsync;
SAI_TxSetConfig(self->i2s_inst, &saiConfig);
} else if ((self->mode == RX) && (i2s_gpio_map[sck_index].mode == RX)) {
saiConfig.syncMode = kSAI_ModeAsync;
SAI_RxSetConfig(self->i2s_inst, &saiConfig);
} else if ((self->mode == TX) && (i2s_gpio_map[sck_index].mode == RX)) {
saiConfig.syncMode = kSAI_ModeAsync;
SAI_RxSetConfig(self->i2s_inst, &saiConfig);
saiConfig.bitClock.bclkSrcSwap = true;
saiConfig.syncMode = kSAI_ModeSync;
SAI_TxSetConfig(self->i2s_inst, &saiConfig);
} else if ((self->mode == RX) && (i2s_gpio_map[sck_index].mode == TX)) {
saiConfig.syncMode = kSAI_ModeAsync;
SAI_TxSetConfig(self->i2s_inst, &saiConfig);
saiConfig.syncMode = kSAI_ModeSync;
SAI_RxSetConfig(self->i2s_inst, &saiConfig);
} else {
return false; // should never happen
}
SAI_TxSetBitClockRate(self->i2s_inst, clock_freq, self->rate, get_dma_bits(self->mode, self->bits),
SAI_NUM_AUDIO_CHANNELS);
SAI_RxSetBitClockRate(self->i2s_inst, clock_freq, self->rate, get_dma_bits(self->mode, self->bits),
SAI_NUM_AUDIO_CHANNELS);
edma_transfer_config_t transferConfig;
uint8_t bytes_per_sample = get_dma_bits(self->mode, self->bits) / 8;
if (self->mode == TX) {
uint32_t destAddr = SAI_TxGetDataRegisterAddress(self->i2s_inst, SAI_CHANNEL_0);
EDMA_PrepareTransfer(&transferConfig,
self->dma_buffer_dcache_aligned, bytes_per_sample,
(void *)destAddr, bytes_per_sample,
(FSL_FEATURE_SAI_FIFO_COUNT - saiConfig.fifo.fifoWatermark) * bytes_per_sample,
SIZEOF_DMA_BUFFER_IN_BYTES, kEDMA_MemoryToPeripheral);
} else { // RX
uint32_t srcAddr = SAI_RxGetDataRegisterAddress(self->i2s_inst, SAI_CHANNEL_0);
EDMA_PrepareTransfer(&transferConfig,
(void *)srcAddr, bytes_per_sample,
self->dma_buffer_dcache_aligned, bytes_per_sample,
(FSL_FEATURE_SAI_FIFO_COUNT - saiConfig.fifo.fifoWatermark) * bytes_per_sample,
SIZEOF_DMA_BUFFER_IN_BYTES, kEDMA_PeripheralToMemory);
}
memset(self->edmaTcd, 0, sizeof(edma_tcd_t));
// continuous DMA operation is achieved using the scatter/gather feature, with one TCD linked back to itself
EDMA_TcdSetTransferConfig(self->edmaTcd, &transferConfig, self->edmaTcd);
EDMA_TcdEnableInterrupts(self->edmaTcd, kEDMA_MajorInterruptEnable | kEDMA_HalfInterruptEnable);
EDMA_InstallTCD(DMA0, self->dma_channel, self->edmaTcd);
EDMA_StartTransfer(&self->edmaHandle);
if (self->mode == TX) {
SAI_TxEnableDMA(self->i2s_inst, kSAI_FIFORequestDMAEnable, true);
SAI_TxEnable(self->i2s_inst, true);
SAI_TxSetChannelFIFOMask(self->i2s_inst, kSAI_Channel0Mask);
} else { // RX
SAI_RxEnableDMA(self->i2s_inst, kSAI_FIFORequestDMAEnable, true);
SAI_RxEnable(self->i2s_inst, true);
SAI_RxSetChannelFIFOMask(self->i2s_inst, kSAI_Channel0Mask);
}
return true;
}
STATIC void mp_machine_i2s_init_helper(machine_i2s_obj_t *self, mp_arg_val_t *args) {
// is Mode valid?
uint16_t i2s_mode = args[ARG_mode].u_int;
if ((i2s_mode != (RX)) &&
(i2s_mode != (TX))) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid mode"));
}
// are I2S pin assignments valid?
uint16_t not_used;
// is SCK valid?
const machine_pin_obj_t *pin_sck = pin_find(args[ARG_sck].u_obj);
if (!lookup_gpio(pin_sck, SCK, self->i2s_id, &not_used)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid SCK pin"));
}
// is WS valid?
const machine_pin_obj_t *pin_ws = pin_find(args[ARG_ws].u_obj);
if (!lookup_gpio(pin_ws, WS, self->i2s_id, &not_used)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid WS pin"));
}
// is SD valid?
const machine_pin_obj_t *pin_sd = pin_find(args[ARG_sd].u_obj);
uint16_t mapping_index;
bool invalid_sd = true;
if (lookup_gpio(pin_sd, SD, self->i2s_id, &mapping_index)) {
if (i2s_mode == i2s_gpio_map[mapping_index].mode) {
invalid_sd = false;
}
}
if (invalid_sd) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid SD pin"));
}
// is MCK defined and valid?
const machine_pin_obj_t *pin_mck = NULL;
if (args[ARG_mck].u_obj != mp_const_none) {
pin_mck = pin_find(args[ARG_mck].u_obj);
if (!lookup_gpio(pin_mck, MCK, self->i2s_id, &not_used)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid MCK pin"));
}
}
// 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?
int32_t i2s_rate = args[ARG_rate].u_int;
if (!is_rate_supported(i2s_rate)) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid rate"));
}
// 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 = pin_sck;
self->ws = pin_ws;
self->sd = pin_sd;
self->mck = pin_mck;
self->mode = i2s_mode;
self->bits = i2s_bits;
self->format = i2s_format;
self->rate = i2s_rate;
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;
self->i2s_inst = (I2S_Type *)i2s_base_ptr[self->i2s_id];
// init the I2S bus
if (!i2s_init(self)) {
mp_raise_msg_varg(&mp_type_OSError, MP_ERROR_TEXT("I2S init failed"));
}
}
STATIC machine_i2s_obj_t *mp_machine_i2s_make_new_instance(mp_int_t i2s_id) {
if (i2s_id < 1 || i2s_id > MICROPY_HW_I2S_NUM) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("I2S(%d) does not exist"), i2s_id);
}
uint8_t i2s_id_zero_base = i2s_id - 1;
machine_i2s_obj_t *self;
if (MP_STATE_PORT(machine_i2s_obj)[i2s_id_zero_base] == NULL) {
self = mp_obj_malloc(machine_i2s_obj_t, &machine_i2s_type);
MP_STATE_PORT(machine_i2s_obj)[i2s_id_zero_base] = self;
self->i2s_id = i2s_id;
self->edmaTcd = &edmaTcd[i2s_id_zero_base];
} else {
self = MP_STATE_PORT(machine_i2s_obj)[i2s_id_zero_base];
machine_i2s_deinit(MP_OBJ_FROM_PTR(self));
}
// align DMA buffer to the cache line size (32 bytes)
self->dma_buffer_dcache_aligned = (uint8_t *)((uint32_t)(self->dma_buffer + 0x1f) & ~0x1f);
// fill the DMA buffer with NULLs
memset(self->dma_buffer_dcache_aligned, 0, SIZEOF_DMA_BUFFER_IN_BYTES);
return self;
}
STATIC void mp_machine_i2s_deinit(machine_i2s_obj_t *self) {
// use self->i2s_inst as in indication that I2S object has already been de-initialized
if (self->i2s_inst != NULL) {
EDMA_AbortTransfer(&self->edmaHandle);
if (self->mode == TX) {
SAI_TxSetChannelFIFOMask(self->i2s_inst, 0);
SAI_TxEnableDMA(self->i2s_inst, kSAI_FIFORequestDMAEnable, false);
SAI_TxEnable(self->i2s_inst, false);
SAI_TxReset(self->i2s_inst);
} else { // RX
SAI_RxSetChannelFIFOMask(self->i2s_inst, 0);
SAI_RxEnableDMA(self->i2s_inst, kSAI_FIFORequestDMAEnable, false);
SAI_RxEnable(self->i2s_inst, false);
SAI_RxReset(self->i2s_inst);
}
SAI_Deinit(self->i2s_inst);
free_dma_channel(self->dma_channel);
m_free(self->ring_buffer_storage);
self->i2s_inst = NULL; // flag object as de-initialized
}
}
STATIC void mp_machine_i2s_irq_update(machine_i2s_obj_t *self) {
(void)self;
}
MP_REGISTER_ROOT_POINTER(struct _machine_i2s_obj_t *machine_i2s_obj[MICROPY_HW_I2S_NUM]);
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