// User application
// Function: Accepts two integers as input and prints their sum
// Uses the device driver associated with the FPGA adder to get the sum

#include "stdio.h"
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define READ_CMD (0x0 << 31)
#define WRITE_CMD1 (0x1 << 31)
#define WRITE_CMD2 (0x1 << 30)

#define ADDER_BASE 0xd3000000
#define ADDER_MASK 0x00001fff
#define ADDER_SIZE 0x20000
#define COMMAND_MASK 0x80000000

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

  // Variable declarations
  int val1, val2, result;

  //Ensure proper usage
  if(argc != 3)
  {
    printf("Usage: %s value1 value2\n",argv[0]);
    return -1;
  }
  //assign val1 and val2
  val1 = atoi(argv[1]);
  val2 = atoi(argv[2]);

  //Open the adder as a file
  int fd = open("/dev/adder", O_RDWR|O_SYNC);
  printf("fd %d\n",fd);
  if(!fd)
  {
    printf("Unable to open /dev/adder.  Ensure it exists (major=246, minor=1)\n");
    return -1;
  }	

  // Write the input values
  ioctl(fd, WRITE_CMD1, &val1);
  printf ("%d written as first value\n",val1);
  ioctl(fd, WRITE_CMD2, &val2);
  printf ("%d written as second value\n",val2);

  // Read back output value
  ioctl(fd, READ_CMD, &result);

  printf("The sum of %d and %d is %d\n", val1, val2, result);

	close(fd);
	return 0;
}