介紹

SPI總線由開發，是一種，由四個IO口組成：CS、SCLK、MISO、MOSI;通常用于CPU和外設之間進行通信，常見的SPI總線設備有：TFT LCD、QSPI FLASH、時鐘模塊、IMU等;開發板上集成了兩路SPI總線，本次實驗將重點介紹RT-Thread系統中SPI BSP驅動的移植過程，以NXP MCXA153為例。

移植流程

以SPI0為例

（1） 在board里邊添加相應的外設：配置spi0外設為復位狀態、設置GPIO引腳功能

（2） 添加相應的Kconfig開關，用以指示相應的外設開啟與關閉（本質是通過宏定義或者條件編譯的方式）

（3） 根據SDK_2_14_2_FRDM-MCXA153提供的spi示例工程編寫spi總線驅動，需要實現幾個關鍵的函數

SDK_2_14_2_FRDM-MCXA153

https://mcuxpresso.nxp.com/zh/builder?hw=FRDM-MCXA153

rt_hw_spi_init

spi_configure

斯皮克斯

（4） 添加相應的庫文件依賴：fsl_lpspi.c、fsl_lpspi_edma.c

引腳對應關系

驅動文件

板。

在函數里加入以下代碼 rt_hw_board_init

edma_config_t userConfig = {0};EDMA_GetDefaultConfig(&userConfig);EDMA_Init(DMA0, &userConfig);pin_mux.c

pin_mux.c

在函數里加入以下代碼 BOARD_InitPins

#ifdef BSP_USING_SPI0 RESET_ReleasePeripheralReset(kLPSPI0_RST_SHIFT_RSTn); const port_pin_config_t port1_0_pin56_config = {/* Internal pull-up/down resistor is disabled */ kPORT_PullDisable, /* Low internal pull resistor value is selected. */ kPORT_LowPullResistor, /* Fast slew rate is configured */ kPORT_FastSlewRate, /* Passive input filter is disabled */ kPORT_PassiveFilterDisable, /* Open drain output is disabled */ kPORT_OpenDrainDisable, /* Low drive strength is configured */ kPORT_LowDriveStrength, /* Normal drive strength is configured */ kPORT_NormalDriveStrength, /* Pin is configured as LPSPI0_SDO */ kPORT_MuxAlt2, /* Digital input enabled */ kPORT_InputBufferEnable, /* Digital input is not inverted */ kPORT_InputNormal, /* Pin Control Register fields [15:0] are not locked */ kPORT_UnlockRegister}; /* PORT1_0 (pin 56) is configured as LPSPI0_SDO */ PORT_SetPinConfig(PORT1, 0U, &port1_0_pin56_config); const port_pin_config_t port1_1_pin57_config = {/* Internal pull-up/down resistor is disabled */ kPORT_PullDisable, /* Low internal pull resistor value is selected. */ kPORT_LowPullResistor, /* Fast slew rate is configured */ kPORT_FastSlewRate, /* Passive input filter is disabled */ kPORT_PassiveFilterDisable, /* Open drain output is disabled */ kPORT_OpenDrainDisable, /* Low drive strength is configured */ kPORT_LowDriveStrength, /* Normal drive strength is configured */ kPORT_NormalDriveStrength, /* Pin is configured as LPSPI0_SCK */ kPORT_MuxAlt2, /* Digital input enabled */ kPORT_InputBufferEnable, /* Digital input is not inverted */ kPORT_InputNormal, /* Pin Control Register fields [15:0] are not locked */ kPORT_UnlockRegister}; /* PORT1_1 (pin 57) is configured as LPSPI0_SCK */ PORT_SetPinConfig(PORT1, 1U, &port1_1_pin57_config); const port_pin_config_t port1_2_pin58_config = {/* Internal pull-up/down resistor is disabled */ kPORT_PullDisable, /* Low internal pull resistor value is selected. */ kPORT_LowPullResistor, /* Fast slew rate is configured */ kPORT_FastSlewRate, /* Passive input filter is disabled */ kPORT_PassiveFilterDisable, /* Open drain output is disabled */ kPORT_OpenDrainDisable, /* Low drive strength is configured */ kPORT_LowDriveStrength, /* Normal drive strength is configured */ kPORT_NormalDriveStrength, /* Pin is configured as LPSPI0_SDI */ kPORT_MuxAlt2, /* Digital input enabled */ kPORT_InputBufferEnable, /* Digital input is not inverted */ kPORT_InputNormal, /* Pin Control Register fields [15:0] are not locked */ kPORT_UnlockRegister}; /* PORT1_2 (pin 58) is configured as LPSPI0_SDI */ PORT_SetPinConfig(PORT1, 2U, &port1_2_pin58_config); const port_pin_config_t port1_3_pin59_config = {/* Internal pull-up/down resistor is disabled */ kPORT_PullDisable, /* Low internal pull resistor value is selected. */ kPORT_LowPullResistor, /* Fast slew rate is configured */ kPORT_FastSlewRate, /* Passive input filter is disabled */ kPORT_PassiveFilterDisable, /* Open drain output is disabled */ kPORT_OpenDrainDisable, /* Low drive strength is configured */ kPORT_LowDriveStrength, /* Normal drive strength is configured */ kPORT_NormalDriveStrength, /* Pin is configured as LPSPI0_PCS0 */ kPORT_MuxAlt2, /* Digital input enabled */ kPORT_InputBufferEnable, /* Digital input is not inverted */ kPORT_InputNormal, /* Pin Control Register fields [15:0] are not locked */ kPORT_UnlockRegister}; /* PORT1_3 (pin 59) is configured as LPSPI0_PCS0 */ PORT_SetPinConfig(PORT1, 3U, &port1_3_pin59_config);#endif

板/Kconfig

加入SPI0相關配置

menuconfig BSP_USING_SPI config BSP_USING_SPI bool "Enable SPI" select RT_USING_SPI default y if BSP_USING_SPI config BSP_USING_SPI0 bool "Enable SPI0" default endif

drv_spi.c

spi驅動層修改如下

/* * Copyright (c) 2006-2024, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2024-08-3 hywing The first version for MCXA */#include "rtdevice.h"#include "drv_spi.h"#include "fsl_common.h"#include "fsl_lpspi.h"#include "fsl_lpspi_edma.h"#define DMA_MAX_TRANSFER_COUNT (32767)enum{#ifdef BSP_USING_SPI0 SPI1_INDEX,#endif};struct lpc_spi{ struct rt_spi_bus parent; LPSPI_Type *LPSPIx; clock_attach_id_t clock_attach_id; clock_div_name_t clock_div_name; clock_name_t clock_name; DMA_Type *DMAx; uint8_t tx_dma_chl; uint8_t rx_dma_chl; edma_handle_t dma_tx_handle; edma_handle_t dma_rx_handle; dma_request_source_t tx_dma_request; dma_request_source_t rx_dma_request; lpspi_master_edma_handle_t spi_dma_handle; rt_sem_t sem; char *name;};static struct lpc_spi lpc_obj[] ={#ifdef BSP_USING_SPI0 { .LPSPIx = LPSPI0, .clock_attach_id = kFRO12M_to_LPSPI0, .clock_div_name = kCLOCK_DivLPSPI0, .clock_name = kCLOCK_Fro12M, .tx_dma_request = kDma0RequestLPSPI0Tx, .rx_dma_request = kDma0RequestLPSPI0Rx, .DMAx = DMA0, .tx_dma_chl = 0, .rx_dma_chl = 1, .name = "spi0", },#endif};struct lpc_sw_spi_cs{ rt_uint32_t pin;};rt_err_t rt_hw_spi_device_attach(const char *bus_name, const char *device_name, rt_uint32_t pin){ rt_err_t ret = RT_EOK;

struct rt_spi_device *spi_device = (struct rt_spi_device *)rt_malloc(sizeof(struct rt_spi_device)); struct lpc_sw_spi_cs *cs_pin = (struct lpc_sw_spi_cs *)rt_malloc(sizeof(struct lpc_sw_spi_cs)); cs_pin->pin = pin; rt_pin_mode(pin, PIN_MODE_OUTPUT); rt_pin_write(pin, PIN_HIGH); ret = rt_spi_bus_attach_device(spi_device, device_name, bus_name, (void *)cs_pin); return ret;}static rt_err_t spi_configure(struct rt_spi_device *device, struct rt_spi_configuration *cfg){ rt_err_t ret = RT_EOK;// struct lpc_spi *spi = RT_NULL;// spi = (struct lpc_spi *)(device->bus->parent.user_data);// ret = lpc_spi_init(spi->SPIx, cfg);

return ret;}static void LPSPI_MasterUserCallback(LPSPI_Type *base, lpspi_master_edma_handle_t *handle, status_t status, void *userData){ struct lpc_spi *spi = (struct lpc_spi *)userData; rt_sem_release(spi->sem);}static rt_ssize_t spixfer(struct rt_spi_device *device, struct rt_spi_message *message)

{ int i; lpspi_transfer_t transfer = {0}; RT_ASSERT(device != RT_NULL); RT_ASSERT(device->bus != RT_NULL);

RT_ASSERT(device->bus->parent.user_data != RT_NULL); struct lpc_spi *spi = (struct lpc_spi *)

(device->bus->parent.user_data); struct lpc_sw_spi_cs *cs = device->parent.user_data; if (message->cs_take) { rt_pin_write(cs->pin, PIN_LOW); } transfer.dataSize = message->length; transfer.rxData = (uint8_t *)(message->recv_buf); transfer.txData = (uint8_t *)(message->send_buf); // if(message->length < MAX_DMA_TRANSFER_SIZE) if (0) { LPSPI_MasterTransferBlocking(spi->LPSPIx, &transfer); } else { uint32_t block, remain; block = message->length / DMA_MAX_TRANSFER_COUNT; remain = message->length % DMA_MAX_TRANSFER_COUNT; for (i = 0; i < block; i++)?

{ transfer.dataSize = DMA_MAX_TRANSFER_COUNT; if (message->recv_buf) transfer.rxData = (uint8_t *)(message->recv_buf + i * DMA_MAX_TRANSFER_COUNT); if (message->send_buf) transfer.txData = (uint8_t *)(message->send_buf + i * DMA_MAX_TRANSFER_COUNT); LPSPI_MasterTransferEDMA(spi->LPSPIx, &spi->spi_dma_handle, &transfer); rt_sem_take(spi->sem, RT_WAITING_FOREVER); }

if (remain) { transfer.dataSize = remain; if (message->recv_buf) transfer.rxData = (uint8_t *)(message->recv_buf + i * DMA_MAX_TRANSFER_COUNT); if (message->send_buf) transfer.txData = (uint8_t *)

(message->send_buf + i * DMA_MAX_TRANSFER_COUNT); LPSPI_MasterTransferEDMA(spi->LPSPIx, &spi->spi_dma_handle, &transfer); rt_sem_take(spi->sem, RT_WAITING_FOREVER); }

} if (message->cs_release) { rt_pin_write(cs->pin, PIN_HIGH); } return message->length;}static struct rt_spi_ops lpc_spi_ops ={ .configure = spi_configure, .xfer = spixfer};int rt_hw_spi_init(void){ int i; for (i = 0; i < ARRAY_SIZE(lpc_obj); i++) { CLOCK_SetClockDiv(lpc_obj[i].clock_div_name, 1u);

CLOCK_AttachClk(lpc_obj[i].clock_attach_id); lpc_obj[i].parent.parent.user_data = &lpc_obj[i]; lpc_obj[i].sem = rt_sem_create("sem_spi", 0, RT_IPC_FLAG_FIFO); lpspi_master_config_t masterConfig; LPSPI_MasterGetDefaultConfig(&masterConfig); masterConfig.baudRate = 12 * 1000 * 1000; masterConfig.pcsToSckDelayInNanoSec = 1000000000U / masterConfig.baudRate * 1U; masterConfig.lastSckToPcsDelayInNanoSec = 1000000000U / masterConfig.baudRate * 1U; masterConfig.betweenTransferDelayInNanoSec = 1000000000U / masterConfig.baudRate * 1U; LPSPI_MasterInit(lpc_obj[i].LPSPIx, &masterConfig, CLOCK_GetFreq(lpc_obj[i].clock_name)); EDMA_CreateHandle(&lpc_obj[i].dma_tx_handle, lpc_obj[i].DMAx,

lpc_obj[i].tx_dma_chl); EDMA_CreateHandle(&lpc_obj[i].dma_rx_handle, lpc_obj[i].DMAx, lpc_obj[i].rx_dma_chl); EDMA_SetChannelMux(lpc_obj[i].DMAx, lpc_obj[i].tx_dma_chl,

lpc_obj[i].tx_dma_request);

EDMA_SetChannelMux(lpc_obj[i].DMAx, lpc_obj[i].rx_dma_chl, lpc_obj[i].rx_dma_request); LPSPI_MasterTransferCreateHandleEDMA(lpc_obj[i].LPSPIx, &lpc_obj[i].spi_dma_handle, LPSPI_MasterUserCallback, &lpc_obj[i], &lpc_obj[i].dma_rx_handle, &lpc_obj[i].dma_tx_handle); rt_spi_bus_register(&lpc_obj[i].parent,

lpc_obj[i].name, &lpc_spi_ops); } return RT_EOK;}INIT_DEVICE_EXPORT(rt_hw_spi_init);

SConscript 腳本

在文件里邊加上以下代碼 Libraries/MCXA153/SConscript

if GetDepend('BSP_USING_SPI'): src += ['MCXA153/drivers/fsl_lpspi.c']src+=['MCXA153/drivers/fsl_lpspi_edma.c']

測試用例

打開menuconfig使能spi0驅動

短接MISO和MOSI引腳（P1_0和P1_2）進行自發自收測試

測試程序

#include #include "rtdevice.h" #include "drv_spi.h"#define SPI_BUS_NAME "spi0" #define SPI_DEV_NAME "spi00" static struct rt_spi_device *spi_device;static void spi_sample(void) { rt_err_t result; struct rt_spi_configuration cfg; uint8_t tx_buf[] = "Hello RT-Thread!"; uint8_t rx_buf[sizeof(tx_buf)]; rt_base_t cs = 1*32+3; rt_hw_spi_device_attach(SPI_BUS_NAME, SPI_DEV_NAME, cs); /* ??è?SPIéè±? */ spi_device = (struct rt_spi_device *)rt_device_find(SPI_DEV_NAME); if (!spi_device) { rt_kprintf("can't find %s device!\n", SPI_BUS_NAME); } /* ????SPIéè±? */ cfg.data_width = 8; cfg.mode = RT_SPI_MASTER | RT_SPI_MODE_0 | RT_SPI_MSB; cfg.max_hz = 12* 1000 * 1000; /* éè??SPIéè±? */ rt_spi_configure(spi_device, &cfg); result = rt_spi_transfer(spi_device, tx_buf, rx_buf, sizeof(tx_buf)); if (result == sizeof(tx_buf)) { rt_kprintf("Send: %s\n", tx_buf); rt_kprintf("Received: %s\n", rx_buf); } else { rt_kprintf("spi transfer failed! error code: %d\n", result); } } int main(void) { spi_sample(); return 0; }

運行結果

總結

另外，你也可以安裝，通過圖形方式配置時鐘樹、GPIO復用 MCUXpresso Config Tools v16