test_spioc.c

it is character driver

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>


int main(int argc, char **argv)
{   
	int t;
	int portfd;
	char wstr[32], rstr[32];
	int number;

	portfd = open("/dev/spioc", O_RDWR | O_NOCTTY | O_NDELAY);
	if(portfd == -1) 
	{
		printf("cannot open /dev/spioc.\n");
		return -1;
	}
	else
	{
		printf("open /dev/spioc successful.\n");
	}

	printf("write string abcdefghij to spioc\n");
	strcpy(wstr, "abcdefghij");
	number = strlen(wstr) - 1;
	write(portfd, wstr, number);
  for(t=1;t<1000000;t++);
		printf("read data from spioc\n");
	read(portfd, rstr, number);
	rstr[number] = 0;
	printf("the output string is %s.\n", rstr);

	close(portfd);

	return 0;
}