/*
 *  main.c
 */

#include <sys/time.h>
#include <time.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>

#define mx21gpio_MAJOR 240

#define MAP_SIZE 4UL
#define MAP_MASK (MAP_SIZE - 1)

#define READ_CMD (0x0 << 31)
#define WRITE_CMD (0x1 << 31)

#define GPIO_BASE 0x10015000
#define GPIO_MASK 0x00000fff
#define GPIO_SIZE 0x600
#define COMMAND_MASK 0x80000000

int num_int = 0;
int det_int = 0;
double delta, tmp_delta;
float time_buf;
int fd;
unsigned long target_addr;
unsigned int value;

void sighandler(int signo)
{

   if (signo == SIGIO)
   {
      // Deassert PB10, Get final time
      value = 1000; 
      ioctl(fd, WRITE_CMD, &value);
      det_int++;
   }

   printf("\nMAIN: Interrupt captured by SIGIO\n");

   return;  /* Return to main loop */

}

char buffer[4096];

int main(int argc, char **argv) {

   int rc, fc;
   struct sigaction action;

   sigemptyset(&action.sa_mask);
   sigaddset(&action.sa_mask, SIGIO);
    
   action.sa_handler = sighandler;
   action.sa_flags = 0;

   sigaction(SIGIO, &action, NULL);
    
   fd = open("/dev/gpio", O_RDWR);
   if (fd == -1) 
   {
      perror("MAIN: Unable to open /dev/gpio");
      rc = fd;
      exit (-1);
   }
    
   printf("\nMAIN: /dev/gpio opened successfully\n");    	

   fc = fcntl(fd, F_SETOWN, getpid());
 
   if (fc == -1) 
   {
      perror("MAIN: SETOWN failed\n");
      rc = fd;
      exit (-1);
   } 
      
   fc= fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_ASYNC);

   if (fc == -1) 
   {
      perror("SETFL failed\n");
      rc = fd;
      exit (-1);
   }   

   // Assert PB10, Get initial time
   value = 1001; 
   ioctl(fd, WRITE_CMD, &value);

   printf("MAIN: Wait for a day...\n");
   sleep(86400);
   // num_int++;
        
   printf("MAIN: INTERRUPT LATENCY = %.2lf ms\n", delta);

   return 0;

}