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circuitpython/ports/mimxrt/machine_spi.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2020-2021 Damien P. George
* Copyright (c) 2021 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.
*/
#include "py/runtime.h"
#include "py/mphal.h"
#include "py/mperrno.h"
#include "extmod/machine_spi.h"
#include "modmachine.h"
#include "dma_channel.h"
#include "fsl_cache.h"
#include "fsl_dmamux.h"
#include "fsl_iomuxc.h"
#include "fsl_lpspi.h"
#include "fsl_lpspi_edma.h"
#define DEFAULT_SPI_BAUDRATE (1000000)
#define DEFAULT_SPI_POLARITY (0)
#define DEFAULT_SPI_PHASE (0)
#define DEFAULT_SPI_BITS (8)
#define DEFAULT_SPI_FIRSTBIT (kLPSPI_MsbFirst)
#define DEFAULT_SPI_DRIVE (6)
#define CLOCK_DIVIDER (1)
#define MICROPY_HW_SPI_NUM MP_ARRAY_SIZE(spi_index_table)
#define SCK (iomux_table[index])
#define CS0 (iomux_table[index + 1])
#define SDO (iomux_table[index + 2])
#define SDI (iomux_table[index + 3])
typedef struct _machine_spi_obj_t {
mp_obj_base_t base;
uint8_t spi_id;
uint8_t mode;
uint8_t spi_hw_id;
bool transfer_busy;
LPSPI_Type *spi_inst;
lpspi_master_config_t *master_config;
} machine_spi_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;
STATIC const uint8_t spi_index_table[] = MICROPY_HW_SPI_INDEX;
STATIC LPSPI_Type *spi_base_ptr_table[] = LPSPI_BASE_PTRS;
static const iomux_table_t iomux_table[] = {
IOMUX_TABLE_SPI
};
static uint16_t dma_req_src_rx[] = DMA_REQ_SRC_RX;
static uint16_t dma_req_src_tx[] = DMA_REQ_SRC_TX;
bool lpspi_set_iomux(int8_t spi, uint8_t drive) {
int index = (spi - 1) * 4;
if (SCK.muxRegister != 0) {
IOMUXC_SetPinMux(SCK.muxRegister, SCK.muxMode, SCK.inputRegister, SCK.inputDaisy, SCK.configRegister, 0U);
IOMUXC_SetPinConfig(SCK.muxRegister, SCK.muxMode, SCK.inputRegister, SCK.inputDaisy, SCK.configRegister,
0x1080u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT);
IOMUXC_SetPinMux(CS0.muxRegister, CS0.muxMode, CS0.inputRegister, CS0.inputDaisy, CS0.configRegister, 0U);
IOMUXC_SetPinConfig(CS0.muxRegister, CS0.muxMode, CS0.inputRegister, CS0.inputDaisy, CS0.configRegister,
0x1080u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT);
IOMUXC_SetPinMux(SDO.muxRegister, SDO.muxMode, SDO.inputRegister, SDO.inputDaisy, SDO.configRegister, 0U);
IOMUXC_SetPinConfig(SDO.muxRegister, SDO.muxMode, SDO.inputRegister, SDO.inputDaisy, SDO.configRegister,
0x1080u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT);
IOMUXC_SetPinMux(SDI.muxRegister, SDI.muxMode, SDI.inputRegister, SDI.inputDaisy, SDI.configRegister, 0U);
IOMUXC_SetPinConfig(SDI.muxRegister, SDI.muxMode, SDI.inputRegister, SDI.inputDaisy, SDI.configRegister,
0x1080u | drive << IOMUXC_SW_PAD_CTL_PAD_DSE_SHIFT);
return true;
} else {
return false;
}
}
STATIC void machine_spi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
static const char *firstbit_str[] = {"MSB", "LSB"};
machine_spi_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "SPI(%u, baudrate=%u, polarity=%u, phase=%u, bits=%u, firstbit=%s, gap_ns=%d)",
self->spi_id, self->master_config->baudRate, self->master_config->cpol,
self->master_config->cpha, self->master_config->bitsPerFrame,
firstbit_str[self->master_config->direction], self->master_config->betweenTransferDelayInNanoSec);
}
mp_obj_t machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
enum { ARG_id, ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_gap_ns, ARG_drive };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_baudrate, MP_ARG_INT, {.u_int = DEFAULT_SPI_BAUDRATE} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_POLARITY} },
{ MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_PHASE} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_BITS} },
{ MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_FIRSTBIT} },
{ MP_QSTR_gap_ns, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_drive, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_DRIVE} },
};
static bool clk_init = true;
// Parse the arguments.
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// Get the SPI bus id.
int spi_id = mp_obj_get_int(args[ARG_id].u_obj);
if (spi_id < 0 || spi_id >= MP_ARRAY_SIZE(spi_index_table)) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("SPI(%d) doesn't exist"), spi_id);
}
// Get peripheral object.
uint8_t spi_hw_id = spi_index_table[spi_id]; // the hw spi number 1..n
machine_spi_obj_t *self = m_new_obj(machine_spi_obj_t);
self->base.type = &machine_spi_type;
self->spi_id = spi_id;
self->spi_inst = spi_base_ptr_table[spi_hw_id];
self->spi_hw_id = spi_hw_id;
uint8_t drive = args[ARG_drive].u_int;
if (drive < 1 || drive > 7) {
drive = DEFAULT_SPI_DRIVE;
}
if (clk_init) {
clk_init = false;
/*Set clock source for LPSPI*/
CLOCK_SetMux(kCLOCK_LpspiMux, 1); // Clock source is kCLOCK_Usb1PllPfd1Clk
CLOCK_SetDiv(kCLOCK_LpspiDiv, CLOCK_DIVIDER);
}
lpspi_set_iomux(spi_index_table[spi_id], drive);
LPSPI_Reset(self->spi_inst);
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applies
self->master_config = m_new_obj(lpspi_master_config_t);
LPSPI_MasterGetDefaultConfig(self->master_config);
// Initialise the SPI peripheral.
self->master_config->baudRate = args[ARG_baudrate].u_int;
self->master_config->betweenTransferDelayInNanoSec = 1000000000 / self->master_config->baudRate * 2;
self->master_config->cpol = args[ARG_polarity].u_int;
self->master_config->cpha = args[ARG_phase].u_int;
self->master_config->bitsPerFrame = args[ARG_bits].u_int;
self->master_config->direction = args[ARG_firstbit].u_int;
if (args[ARG_gap_ns].u_int != -1) {
self->master_config->betweenTransferDelayInNanoSec = args[ARG_gap_ns].u_int;
}
LPSPI_MasterInit(self->spi_inst, self->master_config, CLOCK_GetFreq(kCLOCK_Usb1PllPfd0Clk) / (CLOCK_DIVIDER + 1));
return MP_OBJ_FROM_PTR(self);
}
STATIC void machine_spi_init(mp_obj_base_t *self_in, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits, ARG_firstbit, ARG_gap_ns };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_gap_ns, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
};
// Parse the arguments.
machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
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);
// Reconfigure the baudrate if requested.
if (args[ARG_baudrate].u_int != -1) {
self->master_config->baudRate = args[ARG_baudrate].u_int;
self->master_config->betweenTransferDelayInNanoSec = 1000000000 / self->master_config->baudRate * 2;
}
// Reconfigure the format if requested.
if (args[ARG_polarity].u_int != -1) {
self->master_config->cpol = args[ARG_polarity].u_int;
}
if (args[ARG_phase].u_int != -1) {
self->master_config->cpha = args[ARG_phase].u_int;
}
if (args[ARG_bits].u_int != -1) {
self->master_config->bitsPerFrame = args[ARG_bits].u_int;
}
if (args[ARG_firstbit].u_int != -1) {
self->master_config->direction = args[ARG_firstbit].u_int;
}
if (args[ARG_gap_ns].u_int != -1) {
self->master_config->betweenTransferDelayInNanoSec = args[ARG_gap_ns].u_int;
}
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applies
LPSPI_MasterInit(self->spi_inst, self->master_config, CLOCK_GetFreq(kCLOCK_Usb1PllPfd0Clk) / (CLOCK_DIVIDER + 1));
}
void LPSPI_EDMAMasterCallback(LPSPI_Type *base, lpspi_master_edma_handle_t *handle, status_t status, void *self_in) {
machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
self->transfer_busy = false;
}
STATIC void machine_spi_transfer(mp_obj_base_t *self_in, size_t len, const uint8_t *src, uint8_t *dest) {
machine_spi_obj_t *self = (machine_spi_obj_t *)self_in;
// Use DMA for large transfers if channels are available
const size_t dma_min_size_threshold = 16; // That's the FIFO size
int chan_tx = -1;
int chan_rx = -1;
if (len >= dma_min_size_threshold) {
// Use two DMA channels to service the two FIFOs
chan_rx = allocate_dma_channel();
chan_tx = allocate_dma_channel();
}
bool use_dma = chan_rx >= 0 && chan_tx >= 0;
if (use_dma) {
edma_config_t userConfig;
/* DMA MUX init*/
DMAMUX_Init(DMAMUX);
DMAMUX_SetSource(DMAMUX, chan_rx, dma_req_src_rx[self->spi_hw_id]); // ## SPIn source
DMAMUX_EnableChannel(DMAMUX, chan_rx);
DMAMUX_SetSource(DMAMUX, chan_tx, dma_req_src_tx[self->spi_hw_id]);
DMAMUX_EnableChannel(DMAMUX, chan_tx);
EDMA_GetDefaultConfig(&userConfig);
EDMA_Init(DMA0, &userConfig);
lpspi_master_edma_handle_t g_master_edma_handle;
edma_handle_t lpspiEdmaMasterRxRegToRxDataHandle;
edma_handle_t lpspiEdmaMasterTxDataToTxRegHandle;
// Set up lpspi EDMA master
EDMA_CreateHandle(&(lpspiEdmaMasterRxRegToRxDataHandle), DMA0, chan_rx);
EDMA_CreateHandle(&(lpspiEdmaMasterTxDataToTxRegHandle), DMA0, chan_tx);
LPSPI_MasterTransferCreateHandleEDMA(self->spi_inst, &g_master_edma_handle, LPSPI_EDMAMasterCallback, self,
&lpspiEdmaMasterRxRegToRxDataHandle,
&lpspiEdmaMasterTxDataToTxRegHandle);
// Start master transfer
lpspi_transfer_t masterXfer;
masterXfer.txData = (uint8_t *)src;
masterXfer.rxData = (uint8_t *)dest;
masterXfer.dataSize = len;
masterXfer.configFlags = kLPSPI_MasterPcs0 | kLPSPI_MasterPcsContinuous | kLPSPI_MasterByteSwap;
// Reconfigure the TCR, required after switch between DMA vs. non-DMA
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applied
self->spi_inst->TCR = LPSPI_TCR_CPOL(self->master_config->cpol) | LPSPI_TCR_CPHA(self->master_config->cpha) |
LPSPI_TCR_LSBF(self->master_config->direction) | LPSPI_TCR_FRAMESZ(self->master_config->bitsPerFrame - 1) |
(self->spi_inst->TCR & LPSPI_TCR_PRESCALE_MASK) | LPSPI_TCR_PCS(self->master_config->whichPcs);
LPSPI_Enable(self->spi_inst, true);
self->transfer_busy = true;
if (dest) {
L1CACHE_DisableDCache();
} else if (src) {
DCACHE_CleanByRange((uint32_t)src, len);
}
LPSPI_MasterTransferEDMA(self->spi_inst, &g_master_edma_handle, &masterXfer);
while (self->transfer_busy) {
MICROPY_EVENT_POLL_HOOK
}
L1CACHE_EnableDCache();
}
// Release DMA channels, even if never allocated.
if (chan_rx >= 0) {
free_dma_channel(chan_rx);
}
if (chan_tx >= 0) {
free_dma_channel(chan_tx);
}
if (!use_dma) {
// Reconfigure the TCR, required after switch between DMA vs. non-DMA
LPSPI_Enable(self->spi_inst, false); // Disable first before new settings are applied
self->spi_inst->TCR = LPSPI_TCR_CPOL(self->master_config->cpol) | LPSPI_TCR_CPHA(self->master_config->cpha) |
LPSPI_TCR_LSBF(self->master_config->direction) | LPSPI_TCR_FRAMESZ(self->master_config->bitsPerFrame - 1) |
(self->spi_inst->TCR & LPSPI_TCR_PRESCALE_MASK) | LPSPI_TCR_PCS(self->master_config->whichPcs);
LPSPI_Enable(self->spi_inst, true);
lpspi_transfer_t masterXfer;
masterXfer.txData = (uint8_t *)src;
masterXfer.rxData = (uint8_t *)dest;
masterXfer.dataSize = len;
masterXfer.configFlags = kLPSPI_MasterPcs0 | kLPSPI_MasterPcsContinuous | kLPSPI_MasterByteSwap;
LPSPI_MasterTransferBlocking(self->spi_inst, &masterXfer);
}
}
STATIC const mp_machine_spi_p_t machine_spi_p = {
.init = machine_spi_init,
.transfer = machine_spi_transfer,
};
const mp_obj_type_t machine_spi_type = {
{ &mp_type_type },
.name = MP_QSTR_SPI,
.print = machine_spi_print,
.make_new = machine_spi_make_new,
.protocol = &machine_spi_p,
.locals_dict = (mp_obj_dict_t *)&mp_machine_spi_locals_dict,
};
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