timer.c

frv400开发板上的8253计数器的编程

#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/ioctl.h>
#include<sys/types.h>
#include<linux/kd.h>
#include<fcntl.h>
#include<unistd.h>
#include<time.h>

#define	TIMER_IOC_LL		0xdc
#define	TIMER_OPEN		_IOW(TIMER_IOC_LL,0,int)
#define	TIMER			_IOW(TIMER_IOC_LL,1,int)
#define	TIMER_CLOSE		_IOW(TIMER_IOC_LL,2,int)

main() 
{
	int data=0,data1,fd;
	char a,b;
	int music[21]={131,147,165,175,196,220,247,262,294,330,349,392,440,494,523,587,659,698,784,880,987};	
	fd=open("./lltimer",O_RDONLY);
	if(fd<0)
	{
		printf("Device open failed!\n");
	}
	else
	{
		printf("Device opened,fd=%d\n",fd);
		ioctl(fd,TIMER_OPEN,0);
		while(a!='p')			
		{
			a=getchar();
			switch(a)
			{
			case 'q':data=music[0];break;
			case 'w':data=music[1];break;
			case 'e':data=music[2];break;
			case 'r':data=music[3];break;
			case 't':data=music[4];break;
			case 'y':data=music[5];break;
			case 'u':data=music[6];break;
			case 'a':data=music[7];break;
			case 's':data=music[8];break;
			case 'd':data=music[9];break;
			case 'f':data=music[10];break;
			case 'g':data=music[11];break;
			case 'h':data=music[12];break;
			case 'j':data=music[13];break;
			case 'z':data=music[14];break;
			case 'x':data=music[15];break;
			case 'c':data=music[16];break;
			case 'v':data=music[17];break;
			case 'b':data=music[18];break;
			case 'n':data=music[19];break;
			case 'm':data=music[20];break;
			default:break;
			}
			data1=(1000*1190/data);
		
                        ioctl(fd,TIMER,data1);
			usleep(100000);
			ioctl(fd,TIMER_CLOSE,0); 

			ioctl(fd,TIMER_OPEN,0);
		}
	}
	ioctl(fd,TIMER_CLOSE,0); 
	return 0;
}