wordpress 企业站主题武汉网络推广seo
介绍
SPI总线由摩托罗拉公司
开发,是一种全双工同步串行总线
,由四个IO口组成:CS、SCLK、MISO、MOSI;通常用于CPU和外设之间进行通信,常见的SPI总线设备有:TFT LCD、QSPI FLASH、时钟模块、IMU等;NXP-MCXA153
开发板上集成了两路SPI总线,本次实验将重点介绍RT-Thread系统中SPI BSP驱动的移植过程
移植流程
以SPI0为例
① 在board里边添加相应的外设:配置spi0外设为复位状态、设置GPIO引脚功能
② 添加相应的Kconfig开关,用以指示相应的外设开启与关闭(本质是通过宏定义或者条件编译的方式)
③ 根据SDK_2_14_2_FRDM-MCXA153提供的spi示例工程编写spi总线驱动,需要实现几个关键的函数
- rt_hw_spi_init
- spi_configure
- spixfer
④ 添加相应的库文件依赖:fsl_lpspi.c、fsl_lpspi_edma.c
引脚对应关系
序号 | GPIO | function |
---|---|---|
1 | P1_3 | CS |
2 | P1_1 | SCLK |
3 | P1_2 | MISO |
4 | P1_0 | MOSI |
驱动文件
board.c
在rt_hw_board_init
函数里加入以下代码
edma_config_t userConfig = {0};
EDMA_GetDefaultConfig(&userConfig);
EDMA_Init(DMA0, &userConfig);
pin_mux.c
在BOARD_InitPins
函数里加入以下代码
#ifdef BSP_USING_SPI0RESET_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
board/Kconfig
加入SPI0相关配置
menuconfig BSP_USING_SPIconfig BSP_USING_SPIbool "Enable SPI"select RT_USING_SPIdefault yif BSP_USING_SPIconfig BSP_USING_SPI0bool "Enable SPI0"default endif
drv_spi.c
spi驱动层修改如下
/** 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_SPI0SPI1_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
在Libraries/MCXA153/SConscript
文件里边加上以下代码
if GetDepend('BSP_USING_SPI'):src += ['MCXA153/drivers/fsl_lpspi.c']src += ['MCXA153/drivers/fsl_lpspi_edma.c']
测试用例
打开menuconfig使能spi0驱动
短接MISO和MOSI引脚(P1_0和P1_2)进行自发自收测试
测试程序
#include <rtthread.h>
#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);/* »ñÈ¡SPIÉ豸 */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);}/* ÅäÖÃSPIÉ豸 */cfg.data_width = 8;cfg.mode = RT_SPI_MASTER | RT_SPI_MODE_0 | RT_SPI_MSB;cfg.max_hz = 12* 1000 * 1000;/* ÉèÖÃSPIÉ豸 */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;
}
运行结果
总结
- 另外,你也可以安装
MCUXpresso Config Tools v16
,通过图形方式配置时钟树、GPIO复用 - 完整的BSP驱动代码可以在RT-Thread的仓库找到