extint.c

rt 7520采集卡 linux驱动源代码

/*
	FILE NAME: extint.c

	FILE DESCRIPTION:

		Demonstrates usage of an external interrupt.

		Digital I/O port 1 bit 0 (pin number 46) is used to generate
		the external trigger.  This pin must be connected to the
		External Interrupt Input pin ( pin number 51).

		This program sets up a notification function to be called
		when the external interrupt occurs.  This function increments
		a counter which keeps track of the number of external
		interrupts that have occurred.

		A positive edge triggers an external interrupt unless 'n' is
		passed in as the second command argument, which means a
		negative edge triggers an external interrupt.

	PROJECT NAME: Linux DM7520 Driver, Library, and Example Programs

	PROJECT VERSION: (Defined in README.TXT)

	Copyright 2004 RTD Embedded Technologies, Inc.  All Rights Reserved.
*/

#include <stdio.h>	//printf
#include <unistd.h>	//usleep
#include <stdlib.h>	//exit
#include <errno.h>	//errno
#include <slang/slang.h>	//for anykey
#include "dm7520_library.h"

int counter = 0;

int anykey(void) {
    int x;
    SLang_init_tty(-1, 1, 1);
    x = SLang_getkey();
    SLang_reset_tty();    
    return x;
}

void do_async_stuff(void)
{
 counter++;
}

int main(int argc, char * argv[])
{
 FILE * infile;		
 int devno;	//device handler
 char negative = 0;

 if (argc<2) {fprintf(stderr,"Usage: %s <device> [n]\n",argv[0]);exit(1);}

 if (NULL==(infile=fopen(argv[1],"r"))) 
   {
    fprintf(stderr,"Cannot open file, errno=%d\n",errno);
    perror("Error is");
    exit(2);
   }

 if (argc==3) if (argv[2][0]=='n') negative = 1;	//use negative edge of external trigger
 


 devno = fileno(infile);		// get device handler

 InitBoard7520(devno);

 SetDIO1Direction7520(devno, 1);	//set port1 to output
 WriteDIO17520(devno,0); 

 SetEintPolarity7520 ( devno, negative);
 if (negative) printf ("Using external interrupt, negative edge\n");
 else printf ("Using external interrupt, positive edge\n"); 

 SetNotification7520(devno,(unsigned short) IRQS_EXTERNAL_IT,do_async_stuff);



 
 printf("Press any key for positive edge of external Interrupt\n");
 anykey();
 WriteDIO17520(devno,1); 

 usleep(10);

 if (counter==0){ 
	printf("No Interrupt notification\n");
	printf("Press any key for negative edge of external trigger\n");
	anykey();
	WriteDIO17520(devno,0); 
	usleep(10);
	if (counter==0){
		printf("No Interrupt notification\n");
	}
	else {
		printf("Got Interrupt notification\n");
	}
 }
 else {
	 printf("Got Interrupt notification\n");
 }
 printf("Press any key to exit the program\n");
 anykey();


	UnSetNotification7520(devno);

 fclose(infile);
 return(0); 
}