Linux 用户空间spi读写外围驱动

下面是Linux用户空间spi读写外围芯片的驱动程序，例如bcm交换芯片，FPGA等，大同小异，根据实际芯片时序图修改即可。

/*
 * SPI testing utility (using spidev driver)
 *
 * Copyright (c) 2007  MontaVista Software, Inc.
 * Copyright (c) 2007  Anton Vorontsov
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 *
 * Cross-compile with cross-gcc -I/path/to/cross-kernel/include
 
 ***create** zcl
 */


#include
#include
#include
#include
#include


#include
#include
#include


#include
#include


#include


#include




#define BCM53115M_SPI_STATUS_REG 0xFE/*RO*/
#define BCM53115M_SPI_STATUS_SPIF 0x80
#define BCM53115M_SPI_STATUS_RACK 0x20
#define BCM53115M_SPI_STATUS_MDIO 0x04


#define BCM53115M_SPI_PAGE_REG 0xFF/*R/W*/


#define BCM53115M_SPI_DATA_REG 0xF0/*R/W*/


#ifndef ERROR
#define ERROR    (-1)
#endif


#ifndef OK
#define OK       (0)
#endif


static void pabort(const char *s)
{
perror(s);
abort();
}


static const char *device = "/dev/spidev32766.1";
static const char *spiDevice0 = "/dev/spidev32766.0";
static const char *spiDevice1 = "/dev/spidev32766.1";
static const char *spiDevice2 = "/dev/spidev32766.2";
static uint8_t mode ;
static uint8_t bits ;
static uint32_t speed ;




uint8_t SPI_ReadByte_LSB(int fd, uint8_t readAddress)
{
int ret;
uint8_t readCmd[1];
uint8_t spiStateReg[1];
uint8_t receiveData[1];
struct spi_ioc_transfer xfer[2];

readCmd[0] = 0x03;
spiStateReg[0] = readAddress;

memset(xfer, 0, 2*sizeof(struct spi_ioc_transfer));

xfer[0].tx_buf = (unsigned long)readCmd;
xfer[0].len = 1;


xfer[1].tx_buf = (unsigned long)spiStateReg;
xfer[1].rx_buf = (unsigned long)receiveData;
xfer[1].len = 1;

ret = ioctl(fd, SPI_IOC_MESSAGE(2), &xfer);
if (ret < 1)
pabort("can't xfer spi message1");

// printf("receiveData:%x ;\r\n",receiveData[0]);

return receiveData[0];
}


int SPI_WriteByte_LSB(int fd, uint8_t writeAddress, uint8_t writedata)
{
int ret;
uint8_t writeCmd[1];
uint8_t spiStateReg[1];
uint8_t rev[1];
struct spi_ioc_transfer xfer[3];

writeCmd[0] = 0x03;
spiStateReg[0] = writeAddress;
rev[0] = writedata;

memset(xfer, 0, 3*sizeof(struct spi_ioc_transfer));

xfer[0].tx_buf = (unsigned long)writeCmd;
xfer[0].len = 1;

xfer[1].tx_buf = (unsigned long)spiStateReg;
xfer[1].len = 1;

xfer[2].tx_buf = (unsigned long)rev;
xfer[2].len = 1;


ret = ioctl(fd, SPI_IOC_MESSAGE(3), &xfer);
if (ret < 1)
pabort("can't xfer spi message1");
return OK;
}
int SPI_WriteBytes_LSB(int fd, uint8_t reg, uint8_t *data, uint8_t length)
{
int ret;
uint8_t writeCmd[1];
uint8_t spiStateReg[1];
uint8_t receiveData[1];
struct spi_ioc_transfer xfer[3];

writeCmd[0] = 0x02;
spiStateReg[0] = reg;
memset(xfer, 0, 3*sizeof(struct spi_ioc_transfer));

xfer[0].tx_buf = (unsigned long)writeCmd;
xfer[0].len = 1;

xfer[1].tx_buf = (unsigned long)spiStateReg;
xfer[1].len = 1;

xfer[2].tx_buf = (unsigned long)data;
xfer[2].len = length;

ret = ioctl(fd, SPI_IOC_MESSAGE(3), &xfer);
if (ret < 1)
pabort("can't xfer spi message1");
return OK;
}
int SPI_ReadBytes_LSB(int fd, uint8_t reg, uint8_t *data, uint8_t length)
{
int ret,i;
uint8_t readCmd[1];
uint8_t spiStateReg[1];
uint8_t receiveData[8];
struct spi_ioc_transfer xfer[3];

readCmd[0] = 0x03;
spiStateReg[0] = reg;
memset(xfer, 0, 3*sizeof(struct spi_ioc_transfer));

xfer[0].tx_buf = (unsigned long)readCmd;
xfer[0].len = 1;

xfer[1].tx_buf = (unsigned long)spiStateReg;
xfer[1].len = 1;

xfer[2].rx_buf = (unsigned long)receiveData;
xfer[2].len = length;

ret = ioctl(fd, SPI_IOC_MESSAGE(3), &xfer);
if (ret < 1)
pabort("can't xfer spi message1");



for(i = length; i>0; i--)
{
printf(" rxbuf[%d] = 0x %02x \r\n", (i-1), receiveData[i-1]);
}

return OK;
}






static void print_usage(const char *prog)
{
printf("Usage: %s [-D]\n", prog);
puts("  -D --device   device to use (default /dev/spidev1.1)\n"
   );
exit(1);
}


static void parse_opts(int argc, char *argv[])
{
while (1) 
{
static const struct option lopts[] = 
{
{ "device",  1, 0, 'D' },
{ NULL, 0, 0, 0 },
};
int c;


c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR24", lopts, NULL);


if (c == -1)
break;


switch (c) 
{
case 'D':
device = optarg;
break;

default:
print_usage(argv[0]);
break;
}
}

}
static int spidev_usage(void)
{
printf ("Usage : ./spi cs get   \n"
"        ./spi cs set   \n");
return 0;
}
unsigned int axtoi(char *str)
{
unsigned int result = 0;


char *p =  NULL;


if(str == NULL)
{
return 0;
}
else
if(str[0] == 'x' || str[0] == 'X')
{
p = str+1;
}
else
if(str[0] == '0')
{
if(str[1] == 'x' || str[1] == 'X')
{
p = str+2;
}
else
{
p = str;
}
}
else
{
p = str;
}


while(*p != '\0')
{
if('0' <= *p && *p <= '9')
result = result * 16 + (*p - 0x30);
else
if('a' <= *p && *p <= 'f')
result = result * 16 + (*p - 0x61 + 10);
else
if('A' <= *p && *p <= 'F')
result = result * 16 + (*p - 0x41 + 10);
else
return result;
p++;
}


return result;
}


int main(int argc, char *argv[])
{
int ret = 0;
int fd;
uint8_t buf[4]={};
uint8_t *bp;

int read_flag = 0;
int write_flag = 0;
int i;
unsigned char temp;
unsigned char page = 0;
unsigned char reg = 0;
unsigned char size = 0;
unsigned char txdata[8];
unsigned char rxdata[8];

//parse_opts(argc, argv);
if(argc > 4 && !strcmp("cs0",argv[1]) )
{
fd = open(spiDevice0, O_RDWR);
if (fd < 0)
{
pabort("can't open device");
goto out_close;
}
}
else
if(argc > 4 && !strcmp("cs1",argv[1]) )
{
fd = open(spiDevice1, O_RDWR);
if (fd < 0)
{
pabort("can't open device");
goto out_close;
}
}
else
if(argc > 4 && !strcmp("cs2",argv[1]) )
{
fd = open(spiDevice2, O_RDWR);
if (fd < 0)
{
pabort("can't open device");
goto out_close;
}
}
else
{
return   spidev_usage();
goto out_close;
}
if (argc > 4 && !strcmp("get",argv[2]))
{
read_flag = 1;
reg = strtoul(argv[3],NULL,0);
size = atoi (argv[4]);

if((size<1)||(size>8))
{
printf("\r\n the parameter len must be 1 ~8 !\r\n");
return OK;
}
printf("reg: %x;size:%d; \r\n",reg,size);


}
else if (argc > 4 && !strcmp("set",argv[2]))
{
write_flag = 1;
reg = strtoul(argv[3],NULL,0);
size = argc - 4;

printf("reg: %x;size:%d; \r\n",reg,size);
for(i = size; i>0; i--)
{
txdata[i-1] = (unsigned char)axtoi(argv[size-i+4]);
printf(" data[%d] = 0x %02x \r\n", i-1, txdata[i-1]);
}

}
else return spidev_usage();

if (read_flag)
{
SPI_ReadBytes_LSB(fd,reg, rxdata, size);
}
else if (write_flag)
{
SPI_WriteBytes_LSB(fd, reg, txdata, size);
}
else
spidev_usage();





// bcmreadBytes(fd, 0x02, 0x30, buf,4);

out_close :
close(fd);


return ret;
}