Eric Lee / smarc-fsl-linux-kernel

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Documentation/spi/spidev_fdx.c 2.69 KB
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31a162942   Randy Dunlap   documentation: mo... 
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  #include <stdio.h>
  #include <unistd.h>
  #include <stdlib.h>
  #include <fcntl.h>
  #include <string.h>
  
  #include <sys/ioctl.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  
  #include <linux/types.h>
  #include <linux/spi/spidev.h>
  
  
  static int verbose;
  
  static void do_read(int fd, int len)
  {
  	unsigned char	buf[32], *bp;
  	int		status;
  
  	/* read at least 2 bytes, no more than 32 */
  	if (len < 2)
  		len = 2;
  	else if (len > sizeof(buf))
  		len = sizeof(buf);
  	memset(buf, 0, sizeof buf);
  
  	status = read(fd, buf, len);
  	if (status < 0) {
  		perror("read");
  		return;
  	}
  	if (status != len) {
  		fprintf(stderr, "short read
  ");
  		return;
  	}
  
  	printf("read(%2d, %2d): %02x %02x,", len, status,
  		buf[0], buf[1]);
  	status -= 2;
  	bp = buf + 2;
  	while (status-- > 0)
  		printf(" %02x", *bp++);
  	printf("
  ");
  }
  
  static void do_msg(int fd, int len)
  {
  	struct spi_ioc_transfer	xfer[2];
  	unsigned char		buf[32], *bp;
  	int			status;
  
  	memset(xfer, 0, sizeof xfer);
  	memset(buf, 0, sizeof buf);
  
  	if (len > sizeof buf)
  		len = sizeof buf;
  
  	buf[0] = 0xaa;
1dcf57ceb   Prarit Bhargava   Documentation/spi... 
63
 
  	xfer[0].tx_buf = (unsigned long)buf;
31a162942   Randy Dunlap   documentation: mo... 
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  	xfer[0].len = 1;
1dcf57ceb   Prarit Bhargava   Documentation/spi... 
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  	xfer[1].rx_buf = (unsigned long) buf;
31a162942   Randy Dunlap   documentation: mo... 
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  	xfer[1].len = len;
  
  	status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer);
  	if (status < 0) {
  		perror("SPI_IOC_MESSAGE");
  		return;
  	}
  
  	printf("response(%2d, %2d): ", len, status);
  	for (bp = buf; len; len--)
  		printf(" %02x", *bp++);
  	printf("
  ");
  }
  
  static void dumpstat(const char *name, int fd)
  {
  	__u8	mode, lsb, bits;
  	__u32	speed;
  
  	if (ioctl(fd, SPI_IOC_RD_MODE, &mode) < 0) {
  		perror("SPI rd_mode");
  		return;
  	}
  	if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) {
  		perror("SPI rd_lsb_fist");
  		return;
  	}
  	if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) {
  		perror("SPI bits_per_word");
  		return;
  	}
  	if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) {
  		perror("SPI max_speed_hz");
  		return;
  	}
  
  	printf("%s: spi mode %d, %d bits %sper word, %d Hz max
  ",
  		name, mode, bits, lsb ? "(lsb first) " : "", speed);
  }
  
  int main(int argc, char **argv)
  {
  	int		c;
  	int		readcount = 0;
  	int		msglen = 0;
  	int		fd;
  	const char	*name;
  
  	while ((c = getopt(argc, argv, "hm:r:v")) != EOF) {
  		switch (c) {
  		case 'm':
  			msglen = atoi(optarg);
  			if (msglen < 0)
  				goto usage;
  			continue;
  		case 'r':
  			readcount = atoi(optarg);
  			if (readcount < 0)
  				goto usage;
  			continue;
  		case 'v':
  			verbose++;
  			continue;
  		case 'h':
  		case '?':
  usage:
  			fprintf(stderr,
  				"usage: %s [-h] [-m N] [-r N] /dev/spidevB.D
  ",
  				argv[0]);
  			return 1;
  		}
  	}
  
  	if ((optind + 1) != argc)
  		goto usage;
  	name = argv[optind];
  
  	fd = open(name, O_RDWR);
  	if (fd < 0) {
  		perror("open");
  		return 1;
  	}
  
  	dumpstat(name, fd);
  
  	if (msglen)
  		do_msg(fd, msglen);
  
  	if (readcount)
  		do_read(fd, readcount);
  
  	close(fd);
  	return 0;
  }