#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <inttypes.h>
#include <math.h>


int *pretval;
short *pinval;
unsigned char *pidx_data;

char *base;
size_t len = 1<<(10+2); //4K
int fd;
void *mem;

initfpga()
{

    fd = open("/dev/uio0", O_SYNC|O_RDWR);

    if ( fd < 0 )
    {
	perror("Failed to open /dev/uio0\n"
	       "  Does it exists?\n"
	       "  Check permissions\n"
	       "  Check devicetree\n");
	return -1;
    }

    mem = mmap(NULL, len
		     , PROT_READ | PROT_WRITE, MAP_SHARED, fd
		     , 0);

    if (mem == MAP_FAILED) {
	perror("Can't map memory");
	close(fd);
	return -2;
    }

    /* volatile uint32_t * p = (uint32_t*)mem; */
    base = (char *) mem;

    pretval   =           (int *) (base+0x10);
    pinval    =         (short *) (base+0x18);
    pidx_data = (unsigned char *) (base+0x20);
}

fpgadoit(int in1, int in2)
    {
        unsigned char phi;  /* user input */
        short         mul;  /* user input */
        int retval = 0;
        unsigned short inval;
        unsigned char idx_data;
        register int i;
        register char st, st2;

        mul = (short) in1;
        phi = (unsigned short) in2;

        *pinval = mul;
        *pidx_data = phi;

        i=10000;
        *(base + 0) |= 0x01;
        st2 = *(base+0);
        while (i>0 && ((st = *(base+0)) & 2) == 0 && (st2 & 2) == 0) { i--; }

        retval = *pretval;
        /* printf("Read out: inval=%hd  idx_data=%hhd  retval=%d\n",
           *pinval, *pidx_data, retval); */

    return retval;
}

exitfpga()
{
    //cleanup
    munmap(mem, len);
    close(fd);

    return 0;
}