如何实现Tiny4412通过NRF24L01 2.4G无线模块发送数据呢

Linux下SPI设备驱动该怎样去编写呢？
如何实现tiny4412通过NRF24L01 2.4G无线模块发送数据呢？

孙巍

2021-12-17 11:11:49

硬件平台  ：友善之臂Ting4412
               ： NRF24L01 2.4G无线模块SPI接口
  内核版本：Linux3.5
  硬件连接方式

  以前在STM32F103C8T6上使用STM32的SPI控制器驱动过NRF24L01 2.4G无线模块，最近学习Linux设备驱动，刚好同学手边有一个Tiny4412开发板就当是练练手，顺便学习学习Linux下SPI设备驱动的编写。
  NRF24L01 2.4G无线模块的SPI驱动暂时只是调试通过，能够实现Tiny4412通过NRF24L01 2.4G无线模块发送数据，暂时没写成字符设备驱动，在内核定时器中调用spi_write函数不断发送数据。
  通信现象：

  STM32没接到数据就会报错，如下：

  一旦加载驱动模块，就立马接收正常，如下：

  ......................................................................................只说流程，不说原理............................................................................
  1、构造struct spi_board_info对象，这里我们暂时构造两个，方便以后在SPI0控制器上挂载两个NFR24L01设备，实现相互收发数据。

struct s3c64xx_spi_csinfo cs0={
.fb_delay = 0,
.line = EXYNOS4_GPX3(2),//片选引脚
};
struct s3c64xx_spi_csinfo cs1={
.fb_delay = 0,
.line = EXYNOS4_GPX3(4),//片选引脚
};
static struct spi_board_info nrf24l01_spi_info[]={
{
.modalias = DEV_NAME_01,
.max_speed_hz = 10*1000*1000,//最大时钟，需比设备要求的时钟大，暂选10Mhz
.bus_num = 0,/*exynos4412 的spi0控制器*/
.chip_select = EXYNOS4_GPX3(2),/*由spi master确定其最大值*/
.mode = SPI_MODE_0,
.platform_data = (void*)EXYNOS4_GPX3(3), /*平台数据，作为NRF24LXX的CE引脚*/
.controller_data= (void*)&cs0,
},
{
.modalias = DEV_NAME_02,
.max_speed_hz = 10*1000*1000,//最大时钟，需比设备要求的时钟大，暂选10Mhz
.bus_num = 0,/*exynos4412 的spi0控制器*/
.chip_select = EXYNOS4_GPX3(4),/*由spi master确定其最大值*/
.mode = SPI_MODE_0,
.platform_data = (void*)EXYNOS4_GPX3(5), /*平台数据，作为NRF24LXX的CE引脚*/
.controller_data= (void*)&cs1,
},
};

  2、注册它，内核会依据构造的struct spi_board_info 对象创建对应的struct spi_device对象。
  在init函数中注册构造好的truct spi_board_info对象static struct spi_board_info nrf24l01_spi_info[]

static int __init demo_init(void)
{
printk(KERN_INFO"current func is-------------------------------------------%sn",__FUNCTION__);
/*spi_register_board_info
   *依照spi_board_info 和spi_master的bus_num比较，匹配成功会生成一个对应的spi_device对象
   */
return spi_register_board_info(nrf24l01_spi_info,ARRAY_SIZE(nrf24l01_spi_info));
}

看看spi_register_board_info干了什么？


int spi_register_board_info(struct spi_board_info const *info, unsigned n)
//master和bi->board_info的bus_nus比较，相等则调用spi_new_device创建spi_device对象
spi_match_master_to_boardinfo(master, &bi->board_info);调用spi_new_device
spi_new_device(struct spi_master *master,struct spi_board_info *chip)
int spi_add_device(struct spi_device *spi)//注册struct spi_device
   /*spi_add_device注册struct spi_device时候会做一些判断，一会进去分析 */

分析spi_new_device


int spi_register_board_info(struct spi_board_info const *info, unsigned n)
//master和bi->board_info的bus_nus比较，相等则调用spi_new_device创建spi_device对象
spi_match_master_to_boardinfo(master, &bi->board_info);调用spi_new_device
spi_new_device(struct spi_master *master,struct spi_board_info *chip)
int spi_add_device(struct spi_device *spi)//注册struct spi_device
   /*spi_add_device注册struct spi_device时候会做一些判断，比如我们第一步构造
      *static struct spi_board_info中的chip_select会和spi_master的num_chipselect做比较
*要求设置我们的片选信号不能大于spi_master的num_chipselect
* if (spi->chip_select >= spi->master->num_chipselect) {
* dev_err(dev, "cs%d >= max %dn",spi->chip_select,spi->master->num_chipselect);
* return -EINVAL;//直接报错返回，导致我们不能注册spi_device对象......
* 这个问题怎么解决？我们直接修改spi主控器驱动就好了。
                              *}
* 修改 vi arch/arm/mach-exynos/mach-tiny4412.c中设置spi控制器函数
* s3c64xx_spi0_set_platdata(NULL,0,1)这个函数就好了，内核默认设置
* 最大片选值为1，也就是说默认最多支持1个spi设备，那好了我们把它修改
* 大一些就好了，直接修改到0xffff，保证它一定能注册成功。
*/
至于程序中 struct s3c64xx_spi_csinfo cs0 和struct s3c64xx_spi_csinfo cs1怎么来的？为什么需要这两个？这个是安装驱动后看内核看内核打印错误信息找出来的。出错的地方为 driversspispi-s3c64xx.c的static int s3c64xx_spi_setup(struct spi_device *spi)函数中报if (IS_ERR_OR_NULL(cs)) {
  dev_err(&spi->dev, "No CS for SPI(%d)n", spi->chip_select);
  return -ENODEV;
}
意思是cs为空，那么追溯cs，发现  spi_device spi->controller_data = cs;那好，我们就在 static struct spi_board_info nrf24l01_spi_info[]添加.controller_data= (void*)&cs0即可。


struct s3c64xx_spi_csinfo cs0={
.fb_delay = 0,
.line = EXYNOS4_GPX3(2),
};
struct s3c64xx_spi_csinfo cs1={
.fb_delay = 0,
.line = EXYNOS4_GPX3(4),
};
好了下面编译成模块，但是编译的时候报WARNING: "spi_register_board_info"/nrf24xx_spi_device.ko] undefined!第一感觉是

  spi_register_board_info相关的头文件没有，但是相关spi的头文件都加了，查资料发现原来是linux3.5源码中没有将spi_register_board_info函数导出符号表。那好，就编译进内核得了，将nrf24xx_spi_device.c复制drivers/spi目录下，修改Makefile，将nrf24xx_spi_device.c编译进内核。下面先给出nrf24xx_spi_device.c源码。



  #include #include #include #include #include #include #include #include #include #include #include   /******************硬件相关的信息****************/ #define DEV_NAME_01  "nrf24xx_spi_01" #define DEV_NAME_02  "nrf24xx_spi_02"  #define DEV1_CS_PIN       EXYNOS4_GPX3(2) #define DEV2_CS_PIN       EXYNOS4_GPX3(4)  #define DEV1_CE_PIN       EXYNOS4_GPX3(3) #define DEV2_CE_PIN       EXYNOS4_GPX3(5) /*       片选引脚接在GPX3_2 */ struct s3c64xx_spi_csinfo cs0={       .fb_delay = 0,       .line       =       EXYNOS4_GPX3(2),//片选引脚 }; struct s3c64xx_spi_csinfo cs1={       .fb_delay = 0,       .line       =       EXYNOS4_GPX3(4),//片选引脚 }; static struct spi_board_info nrf24l01_spi_info[]={       {                .modalias             =       DEV_NAME_01,                .max_speed_hz       =       2*1000*1000,//最大时钟，需比设备要求的时钟大，暂选2Mhz                .bus_num             =       0,/*exynos4412 的spi0控制器*/                .chip_select       =       EXYNOS4_GPX3(2),/*由spi master确定其最大值*/                .mode                      =       SPI_MODE_0,                .platform_data       = (void*)EXYNOS4_GPX3(3), /*平台数据，作为NRF24LXX的CE引脚*/                .controller_data=       (void*)&cs0,       },       {                .modalias             =       DEV_NAME_02,                .max_speed_hz       =       2*1000*1000,//最大时钟，需比设备要求的时钟大，暂选2Mhz                .bus_num             =       0,/*exynos4412 的spi0控制器*/                .chip_select       =       EXYNOS4_GPX3(4),/*由spi master确定其最大值*/                .mode                      =       SPI_MODE_0,                .platform_data       = (void*)EXYNOS4_GPX3(5), /*平台数据，作为NRF24LXX的CE引脚*/                .controller_data=       (void*)&cs1,       }, };  static int __init demo_init(void) {       printk(KERN_INFO"current func is-------------------------------------------%sn",__FUNCTION__);       /*spi_register_board_info          *依照spi_board_info 和spi_master的bus_num比较，匹配成功会生成一个对应的spi_device对象       */       return spi_register_board_info(nrf24l01_spi_info,ARRAY_SIZE(nrf24l01_spi_info)); }  static void __exit demo_exit(void) {       printk(KERN_INFO"current func is-----%sn",__FUNCTION__);       } module_init(demo_init); module_exit(demo_exit); MODULE_LICENSE("GPL");

  make zImage，启动内核。在sys/bus/spi/devices目录下出现下面spi0.220 spi0.222两个节点

其中0表示bus_num,220和222表示我们的static struct spi_board_info nrf24l01_spi_info[0]的.chip_select = EXYNOS4_GPX3(2),//这个宏的值就是220同理222就是EXYNOS4_GPX3(4)，默认内核只创建spi0.0、spi2.0。注意现在只是在内核中创建了spi_device，还没nrf24xx的驱动。nrf24xx_spi_driver就是在STM32程序基础上简单的修修改改就好了，对比Tiny4412和STM32的程序你会发现关于nrf24l01的代码名字是一样的。
  ..............................................................下面就直接给出nrf24xx_spi_driver.c的源码.........................................................................

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

/******************硬件相关的信息****************/
#define DEV_NAME_01  "nrf24xx_spi_01"
#define DEV_NAME_02  "nrf24xx_spi_02"

#define DEV1_CS_PIN    EXYNOS4_GPX3(2)
#define DEV2_CS_PIN    EXYNOS4_GPX3(4)

#define DEV1_CE_PIN    EXYNOS4_GPX3(3)
#define DEV2_CE_PIN    EXYNOS4_GPX3(5)
/*
片选引脚接在GPX3_2
*/
struct s3c64xx_spi_csinfo cs0={
.fb_delay = 0,
.line = EXYNOS4_GPX3(2),//片选引脚
};
struct s3c64xx_spi_csinfo cs1={
.fb_delay = 0,
.line = EXYNOS4_GPX3(4),//片选引脚
};
static struct spi_board_info nrf24l01_spi_info[]={
{
.modalias = DEV_NAME_01,
.max_speed_hz = 2*1000*1000,//最大时钟，需比设备要求的时钟大，暂选2Mhz
.bus_num = 0,/*exynos4412 的spi0控制器*/
.chip_select = EXYNOS4_GPX3(2),/*由spi master确定其最大值*/
.mode = SPI_MODE_0,
.platform_data = (void*)EXYNOS4_GPX3(3), /*平台数据，作为NRF24LXX的CE引脚*/
.controller_data= (void*)&cs0,
},
{
.modalias = DEV_NAME_02,
.max_speed_hz = 2*1000*1000,//最大时钟，需比设备要求的时钟大，暂选2Mhz
.bus_num = 0,/*exynos4412 的spi0控制器*/
.chip_select = EXYNOS4_GPX3(4),/*由spi master确定其最大值*/
.mode = SPI_MODE_0,
.platform_data = (void*)EXYNOS4_GPX3(5), /*平台数据，作为NRF24LXX的CE引脚*/
.controller_data= (void*)&cs1,
},
};

static int __init demo_init(void)
{
printk(KERN_INFO"current func is-------------------------------------------%sn",__FUNCTION__);
/*spi_register_board_info
   *依照spi_board_info 和spi_master的bus_num比较，匹配成功会生成一个对应的spi_device对象
   */
return spi_register_board_info(nrf24l01_spi_info,ARRAY_SIZE(nrf24l01_spi_info));
}

static void __exit demo_exit(void)
{
printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
}
module_init(demo_init);
module_exit(demo_exit);
MODULE_LICENSE("GPL");
就当是记笔记。

李万寿

2021-12-17 11:12:50

编译驱动，并加载模块，在sys/bus/spi/drivers/目录下出现我们的nrf24xxspi驱动，如下图：

  ..................................................................................下面直接给出STM32的源码.........................................................................

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include

#include "nrf24xx.h"

#define DEVICE_NUM 1
#define GPX3CON  0x11000C60
#define GPX3DAT    0x11000C64

#define DEV_NAME_01  "nrf24xx_spi_01"
#define DEV_NAME_02  "nrf24xx_spi_02"
#define DEV_NAME DEV_NAME_01

#define DEV1_CS_PIN    EXYNOS4_GPX3(2)
#define DEV2_CS_PIN    EXYNOS4_GPX3(4)

#define DEV1_CE_PIN    EXYNOS4_GPX3(3)
#define DEV2_CE_PIN    EXYNOS4_GPX3(5)

unsigned char TX_ADDRESS[TX_ADR_WIDTH_5]={0x34,0x43,0x10,0x10,0x01}; //发送地址
unsigned char RX_ADDRESS[TX_ADR_WIDTH_5]={0x34,0x43,0x10,0x10,0x01};

static struct work_struct work;
struct timer_list timer;
struct spi_device *nrf24xx_spi;

static int nrf24l01_spi_probe(struct spi_device *spi);
static int nrf24l01_spi_remove(struct spi_device *spi);

void Nrf24L10_RX_Mode(void);
void Nrf24L10_TX_Mode(void);
unsigned char SPI1_ReadBuf(unsigned char reg,unsigned char *buf,unsigned char length);
unsigned char SPI1_SendBuf(unsigned char reg,unsigned char *buf,unsigned char length);
unsigned char SPI1_Write_Register(unsigned char reg,unsigned char data);
void Active_Nrf24l10(unsigned char cmd);
unsigned int SPI1_Read_Reg(unsigned char reg,unsigned char *status);
unsigned char Nrf24l10_SendBuf(unsigned char* data_buffer, unsigned char length);
unsigned char Nrf24l0_ReceiveBuf(unsigned char *buf);
unsigned char Nrf24l10_Irq(void);

char tmp=0,counter =0;
static struct spi_driver nrf24l01_spi_driver={
.driver={
.name = DEV_NAME,
.bus =&spi_bus_type,
.owner  = THIS_MODULE,
},
.probe = nrf24l01_spi_probe,
.remove =__devexit_p(nrf24l01_spi_remove),
};

static void timer_function(unsigned long counter)
{
//printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
tmp = tmp?0:1;
gpio_set_value(DEV2_CE_PIN,tmp);
mod_timer(&timer,jiffies+HZ);
schedule_work(&work);

}
/*中断底半部中发送数据*/
static void irqBottom(struct work_struct *work)
{
char wbuf[50]={0};
int ret =0;
// char reg = EN_AA;
counter = counter>30? 0:counter;
sprintf(wbuf,"Message Comes From Linux -%d %c",counter,'');
counter++;
ret = Nrf24l10_SendBuf(wbuf,RX_PLOAD_WIDTH_32);//该函数会导致休眠，不能在中断函数中使用
printk("Message Send to STM3 .......%dn",counter);
}
static int nrf24l01_spi_probe(struct spi_device *spi)
{
nrf24xx_spi = spi;
printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
printk(KERN_INFO"max_speed_hz:%dn",spi->max_speed_hz);
printk(KERN_INFO"chip_select:%dn",spi->chip_select);
INIT_WORK(&work, irqBottom);
s3c_gpio_cfgpin(DEV1_CS_PIN, S3C_GPIO_OUTPUT);//设置片选为输出
s3c_gpio_cfgpin(DEV2_CS_PIN, S3C_GPIO_OUTPUT);//设置片选为输出

s3c_gpio_cfgpin(DEV1_CE_PIN, S3C_GPIO_OUTPUT);//设置片选为输出
s3c_gpio_cfgpin(DEV2_CE_PIN, S3C_GPIO_INPUT);//设置片选为输出
Nrf24L10_TX_Mode();
init_timer(&timer);//初始化内核定时器
timer.function = timer_function;
add_timer(&timer);
return 0;
}

static int nrf24l01_spi_remove(struct spi_device *spi)
{
printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
del_timer(&timer);
return 0;
}

static int __init demo_init(void)
{
int err;
printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
err = spi_register_driver(&nrf24l01_spi_driver);
return err;
}

static void __exit demo_exit(void)
{
printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
spi_unregister_driver(&nrf24l01_spi_driver);
}

module_init(demo_init);
module_exit(demo_exit);
MODULE_LICENSE("GPL");

void Nrf24L10_RX_Mode(void)
{
Active_Nrf24l10(0);//进入设置模式
SPI1_SendBuf(WRITE_REG1 + RX_ADDR_P0, RX_ADDRESS, TX_ADR_WIDTH_5);       //数据通道0发送地址，最大5个字节
SPI1_Write_Register(WRITE_REG1 + EN_AA, 0x01); // 使能通道0-通道5接收自动应答
SPI1_Write_Register(WRITE_REG1 + EN_RXADDR, 0x01); //接收通道0-5 使能
SPI1_Write_Register(WRITE_REG1 + RF_CH, 40);       // 选择射频工作频道0 范围0-127  频道选择寄存器
SPI1_Write_Register(WRITE_REG1+RX_PW_P0,RX_PLOAD_WIDTH_32);
SPI1_Write_Register(WRITE_REG1 + RF_SETUP, 0x0f);
SPI1_Write_Register(WRITE_REG1 + CONFIG, 0x0f);
Active_Nrf24l10(1);//激活发送
}

void Nrf24L10_TX_Mode(void)
{
Active_Nrf24l10(0);
SPI1_SendBuf(WRITE_REG1 + TX_ADDR, TX_ADDRESS, TX_ADR_WIDTH_5);  //数据通道0发送地址，最大5个字节
SPI1_SendBuf(WRITE_REG1 + RX_ADDR_P0, RX_ADDRESS, TX_ADR_WIDTH_5);//数据通道0发送地址，最大5个字节

SPI1_Write_Register(WRITE_REG1 + EN_AA, 0x01);// 使能通道0-通道5接收自动应答
SPI1_Write_Register(WRITE_REG1 + EN_RXADDR, 0x01);//接收通道0-5 使能
SPI1_Write_Register(WRITE_REG1+SETUP_RETR,0x1a);
SPI1_Write_Register(WRITE_REG1 + RF_CH, 40);// 选择射频工作频道0 范围0-127  频道选择寄存器
SPI1_Write_Register(WRITE_REG1 + RF_SETUP, 0x0f);
SPI1_Write_Register(WRITE_REG1 + CONFIG, 0x0e);
Active_Nrf24l10(1); // 使能发送模式
}

unsigned int SPI1_Read_Reg(unsigned char reg,unsigned char *status)
{
unsigned char wbuf=reg;
struct spi_message m;
struct spi_transfer t[2] = {
{
.tx_buf = &wbuf,
.len = 1,
},
{
.rx_buf = status,
.len = 1,
},
};
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
return spi_sync(nrf24xx_spi, &m);
}

unsigned char SPI1_Write_Register(unsigned char reg,unsigned char data)
{
unsigned char wbuf[2]={0};

struct spi_message m;
struct spi_transfer t = {
.tx_buf = wbuf,
.len = 2,
};
//printk(KERN_INFO"current func is-----%sn",__FUNCTION__);
wbuf[0]=reg;
wbuf[1]=data;
spi_message_init(&m);
spi_message_add_tail(&t, &m);
return spi_sync(nrf24xx_spi, &m);
}

/*
SPI1发送一个缓冲区
*/

unsigned char SPI1_SendBuf(unsigned char reg,unsigned char *buf,unsigned char length)
{
struct spi_message m;
unsigned char wbuf=reg;
struct spi_transfer t[2] = {
{
.tx_buf = &wbuf,
.len = 1,
},
{
.tx_buf = buf,
.len = length,
},

};
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
return spi_sync(nrf24xx_spi, &m);
}
unsigned char SPI1_ReadBuf(unsigned char reg,unsigned char *buf,unsigned char length)
{
unsigned char wbuf=reg;
struct spi_message m;
struct spi_transfer t[2] = {
{
.tx_buf = &wbuf,
.len = 1,
},
{
.rx_buf = buf,
.len = length,
}

};
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
return spi_sync(nrf24xx_spi, &m);
}
void Active_Nrf24l10(unsigned char cmd)
{
gpio_set_value(DEV2_CE_PIN,cmd);
}

unsigned char Nrf24l0_ReceiveBuf(unsigned char *buf)
{
unsigned char status = 0;
SPI1_Read_Reg(STATUS,&status);
SPI1_Write_Register(WRITE_REG1 +STATUS ,status);//清除相应的标志位
if(status & RX_OK)
{
SPI1_ReadBuf(RD_RX_PLOAD,buf,RX_PLOAD_WIDTH_32);
SPI1_Write_Register(FLUSH_RX,0xff);
return RX_OK; //接收成功返回RX_OK
}
return OTHER_ERROR;
}

unsigned char Nrf24l10_SendBuf(unsigned char* data_buffer, unsigned char length)
{
unsigned char status = 0;
Active_Nrf24l10(0);
SPI1_SendBuf(WR_TX_PLOAD,data_buffer,TX_PLOAD_WIDTH_32);//写数据到TX BUF  32个字节
// SPI1_SendBuf(WR_TX_PLOAD,data_buffer,length);//写数据到TX BUF  32个字节
Active_Nrf24l10(1);
while(1 == Nrf24l10_Irq())//等待发送完成事件
{
//printk("Nrf24l10_Irq..............n");
schedule_timeout(HZ/50);//HZ=100 , 每10ms jiffies+1
}
SPI1_Read_Reg(STATUS,&status);
SPI1_Write_Register(WRITE_REG1 +STATUS ,status);//清除相应的标志位
if(status & TX_OK)
{
return TX_OK; //接收成功返回RX_OK
}else if(status & MAX_RET_FLAG)
{
SPI1_Write_Register(FLUSH_TX,0xff);
return MAX_RET_FLAG; //否则返回ERROR
}
return OTHER_ERROR;
}
unsigned char Nrf24l10_Irq(void)
{
return gpio_get_value(DEV2_CE_PIN);
}

新手整整搞了3天才调通，还有有些地方说的不好，见谅。

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孙巍

李万寿

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