准备：
开启树莓派spi功能：
执行：sudo raspi-config
选择 Advanced Options -> SPI -> yes 启动 SPI 内核驱动 运行 lsmod 命令，可以看到 spi 模块“spi_bcm2835”已启动 在 /dev 路径下面，我们可以发现两个 spi 设备 树莓派与w25q64芯片的链接方法上图的网络标号括号内对应树莓派排针的引脚序号。
接下来直接贴代码
#include <stdint.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <getopt.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/spi/spidev.h> #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) #define RX_TX_MAX 1024 static void pabort(const char *s) { perror(s); abort(); } static const char *device = "/dev/spidev0.0"; static uint8_t mode; static uint8_t bits = 8; static uint32_t speed = 1000000; static uint16_t delay; static char* file_name; static uint32_t number_byte=0; static uint8_t read_write_flg=0; //0-read 1-write int spi_fd; static void read_date(int addr,char *buff,int size) { int ret,i; uint8_t rx[RX_TX_MAX]; uint8_t tx[RX_TX_MAX] = { 0x03, 0x00, 0x00, 0x00,0x00, }; tx[1]=(addr&0xFF0000)>>16; tx[2]=(addr&0xFF00)>>8; tx[3]=addr&0xFF; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = size+4, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); for(i=0;i<size;i++) { buff[i]=rx[i+4]; } } static void read_id() { int ret; uint8_t rx[4]; uint8_t tx[4] = { 0x9f, 0xef, 0x00, 0x00, }; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 4, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); printf("%.2X %.2X \n", rx[2],rx[3]); } static char read_reg1() { int ret; uint8_t rx[2]; uint8_t tx[2] = { 0x05, 0x00, }; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 2, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); return rx[1]; } static char read_reg2() { int ret; uint8_t rx[2]; uint8_t tx[2] = { 0x35, 0x00, }; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 2, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); return rx[1]; } static void write_en() { int ret; uint8_t rx[1]; uint8_t tx[1] = { 0x06, }; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 1, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); } static void write_dis() { int ret; uint8_t rx[1]; uint8_t tx[1] = { 0x04, }; struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 1, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); } static void BlockErase64k (int addr) { int ret; uint8_t rx[4]; uint8_t tx[4] = { 0xd8,0x00,0x00,0x00, }; tx[1]=(addr&0xFF0000)>>16; write_en(spi_fd); while(read_reg1(spi_fd)&0x01==0x01); struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = 4, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); while(read_reg1(spi_fd)&0x01==0x01); } static void write_data_page(int addr,char *tx_buff,int size) { int ret,i; uint8_t rx[256+4]; char tx[256+4]; tx[0] =0x02; tx[1]=(addr&0xFF0000)>>16; tx[2]=(addr&0xFF00)>>8; tx[3]=addr&0xFF; write_en(spi_fd); for(i=0;i<256;i++) { tx[4+i]=tx_buff[i]; } struct spi_ioc_transfer tr = { .tx_buf = (unsigned long)tx, .rx_buf = (unsigned long)rx, .len = size+4, .delay_usecs = delay, .speed_hz = speed, .bits_per_word = bits, }; ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &tr); if (ret < 1) pabort("can't send spi message"); while(read_reg1(spi_fd)&0x01==0x01); } static void print_usage(const char *prog) { printf("Usage: %s [-DsbdlHOLC3]\n", prog); puts(" -D --device device to use (default /dev/spidev1.1)\n" " -s --speed max speed (Hz)\n" " -d --delay delay (usec)\n" " -b --bpw bits per word \n" " -r --read read img \n" " -w --writ write img \n" " -n --number Number of bytes read or written \n" " -l --loop loopback\n" " -H --cpha clock phase\n" " -O --cpol clock polarity\n" " -L --lsb least significant bit first\n" " -C --cs-high chip select active high\n" " -3 --3wire SI/SO signals shared\n"); exit(1); } static void parse_opts(int argc, char *argv[]) { while (1) { static const struct option lopts[] = { { "device", 1, 0, 'D' }, { "speed", 1, 0, 's' }, { "delay", 1, 0, 'd' }, { "bpw", 1, 0, 'b' }, { "read", 1, 0, 'r' }, { "write", 1, 0, 'w' }, { "number", 1, 0, 'n' }, { "loop", 0, 0, 'l' }, { "cpha", 0, 0, 'H' }, { "cpol", 0, 0, 'O' }, { "lsb", 0, 0, 'L' }, { "cs-high", 0, 0, 'C' }, { "3wire", 0, 0, '3' }, { "no-cs", 0, 0, 'N' }, { "ready", 0, 0, 'R' }, { NULL, 0, 0, 0 }, }; int c; c = getopt_long(argc, argv, "D:s:d:b:r:w:n:lHOLC3NR", lopts, NULL); if (c == -1) break; switch (c) { case 'D': device = optarg; break; case 's': speed = atoi(optarg); break; case 'd': delay = atoi(optarg); break; case 'b': bits = atoi(optarg); break; case 'r': read_write_flg =1; file_name =optarg; printf("file %s\n",file_name); break; case 'w': read_write_flg =2; file_name = optarg; break; case 'n': number_byte = atoi(optarg); break; case 'l': mode |= SPI_LOOP; break; case 'H': mode |= SPI_CPHA; break; case 'O': mode |= SPI_CPOL; break; case 'L': mode |= SPI_LSB_FIRST; break; case 'C': mode |= SPI_CS_HIGH; break; case '3': mode |= SPI_3WIRE; break; case 'N': mode |= SPI_NO_CS; break; case 'R': mode |= SPI_READY; break; default: print_usage(argv[0]); break; } } } void write_img() { FILE *file = fopen(file_name,"rb"); if(file==0) { printf("open error for \"%s\"", file_name); return; } //擦除块 int i; printf("Eraseing...\n"); for (i = 0; i < (number_byte/64/1024); i++) { BlockErase64k(i*64*1024); printf("Block Erase for %d block %dkB-%dkB\n\33[1A", i,i*64,(i+1)*64); } printf("\nErase finish!\n"); printf("writing...\n"); //给芯片编程 char buff_data[256]; for (i = 0; i < (number_byte/256); i++) { fread(&buff_data,1,256,file); write_data_page(i*256,buff_data,256); if(i%6==0) printf("%dkB\n\33[1A", i*256/1024); } fclose(file); write_dis(); printf("\nwrite finish!\n"); } void read_img() { FILE *file = fopen(file_name,"wb"); if(file==0) { printf("open error for \"%s\"", file_name); return; } printf("reading...\n"); char buff_data[256]; int i; for (i = 0; i < (number_byte)/256; i++) { read_date(i*256,buff_data,256); fwrite(&buff_data,1,256,file); if(i%6==0) printf("%dkB\n\33[1A", i*256/1024); } fclose(file); write_dis(); printf("\nread finish!\n"); } int main(int argc, char *argv[]) { int ret = 0; int i; char aa[256]; parse_opts(argc, argv); spi_fd = open(device, O_RDWR); if (spi_fd < 0) pabort("can't open device"); /* * spi mode */ ret = ioctl(spi_fd, SPI_IOC_WR_MODE, &mode); if (ret == -1) pabort("can't set spi mode"); ret = ioctl(spi_fd, SPI_IOC_RD_MODE, &mode); if (ret == -1) pabort("can't get spi mode"); /* * bits per word */ ret = ioctl(spi_fd, SPI_IOC_WR_BITS_PER_WORD, &bits); if (ret == -1) pabort("can't set bits per word"); ret = ioctl(spi_fd, SPI_IOC_RD_BITS_PER_WORD, &bits); if (ret == -1) pabort("can't get bits per word"); /* * max speed hz */ ret = ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed); if (ret == -1) pabort("can't set max speed hz"); ret = ioctl(spi_fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed); if (ret == -1) pabort("can't get max speed hz"); printf("spi mode: %d\n", mode); printf("bits per word: %d\n", bits); printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000); read_id(); //write if(read_write_flg==1) { read_img(); } else if(read_write_flg==2) { write_img(); } return ret; }编译执行：gcc spi-w25q64.c -o spi-w25q64
编译生成：spi-w25q64
应用使用方法：
1. 读取数据：sudo ./spi-w25q64 -r w25q64.img -n 8388608
-r 跟的参数是将读取的数据保存成w25q64.img文件
-n 跟的参数是要读多少字节
上图“40 17” 是读到的芯片id。
2.芯片编程：sudo ./spi-w25q64 -w w25q64.img -n 8388608
-r 跟的参数是将w25q64.img文件 中的数据写入芯片中。
-n 跟的参数是要读多少字节。
可下载源码：https://download.csdn.net/download/xiaopanpanpanpan/10337072
