/****
 * upload.c                     Andrew Huang                Xtreme Ideas  
 *                             bunnie@mit.edu
 *
 * version 1.0 <8/3/97>
 *  basic DOS support built into program with hooks for linux version
 *
 * version 2.0 <1/23/98>
 *  linux compatibility integrated into code; code cleaned up for 
 *  readibility
 *
 * NOTE: when compiling this under linux, you must use the -O2 compiler flag.
 *           for example, 
 *
 *       gcc -O2 upload.c -o upload
 *
 *    This is because the I/O port instructions turn into in-line assembly.
 *    Also, you must be super-user to run this program.
 ****/

/*** defines ***/
#if 0               /* dos compatibility commented out */
#undef  LINUX 0   
#define DOS 1
#endif

#if 1
#define  LINUX 1    
#undef DOS 
#endif

#undef  SCANARGV   /* scanargv library support; off for max compatibility */

/* debug options */
#define SSTEP 0
#define RHPDEBUG 0

/* open-loop wait parameters
   there is enough "play" in the loop such that this number does not really
   need to be adjusted even if this program is targetted for a variety of
   architectures */
#define WAIT  50


/*** includes ***/
#include "pport.h"

/*** typedefs ***/

/*** globals ***/

/*** func protos ***/
static int flip_byte(int byte);
void init_ports();
void frob_cclk();
void one_byte();
void print_banner();



void main( int argc, char *argv[] ) {
  /* main */
  /* locals */
  unsigned int i, count;
  long  wait;
  FILE *bitstream = NULL;
  char  c;
  int verbose = 0;
  char *fname;

  /* body */
#if SCANARGV
  scanargv( argc, argv, 
	    "%s [-v] [-f filename]", 
	    "[-v %+|-f %r]",
	    &verbose, &bitstream );
#else
  fname = argv[1];
  printf( "Using %s for FPGA bitstream.\n", fname );
  if( NULL IS (bitstream = fopen( fname, "r" ) ) ) {
	printf( "Can't open %s...\n", fname );
	exit(0);
  } /* if */
  verbose = 0;
#endif
  
  if( verbose ) 
    print_banner();

  /***** 
   * init any machine-specific stuph 
   *****/
  init_ports();

  /*****
   * perform a low-level init and clear of the FPGA
   *****/
  /* set strobe to inactive value */
  outb( (char) (inb( LP1_CR ) | CR_STB) & 0xFF, LP1_CR ); /* clear strobe */
  
  /* initialize the LCA */
  /* this is done by slamming init low and holding it there */
  /* then returning it to the high value */
  outb( (char) inb( LP1_CR ) & ~CR_INIT, LP1_CR );
  for( wait = 0; wait < 40000; wait++ )
   ; /* wait for LCA to reset */
  outb( (char) inb( LP1_CR ) | CR_INIT, LP1_CR );

#if RHPDEBUG
  printf( "Initialize array\n" );
  getchar();
#endif

  /* wait for /init to go high */
  /* this allows us to determine if the device is connected */
  count = 0;
  while( !(inb( LP1_SR ) & SR_ERR) ) {
    count++;
    if( count > TIMEOUT ) {
      printf( "Init did not go high; is it plugged in?\n" );
      exit(0);
    } /* if */
  } /* while */
  
  /*****
   * upload the bitstream 
   *****/
  /* scan past the bitfile header */
  c = 0;
  count = 0;
  while( (unsigned char) c AINT 0xFF ) {
    fread( &c, 1, 1, bitstream );
    count++;
  } /* while */
  
  /* set the data output to all 1's to handle weird parallel ports */
  outb( (char) 0xFF, LP1_DR );
  
  /* from cclk once to get the FPGA in the proper state */
  for(wait = 0; wait < 10000; wait++ )
   ;
  frob_cclk(); 
  for(wait = 0; wait < 10000; wait++ )
   ;

#if RHPDEBUG  
  printf( "Entering main loop.\n" );
  getchar();
#endif

  /*****
   * main upload loop
   *****/
  while( !feof( bitstream ) ) {
    fread( &c, 1, 1, bitstream );
    count++; /* keep a running count of bytes processed, incl header */
    
    /* check for error by INIT going low */
    if(!( inb(LP1_SR) & SR_ERR)) {
      printf( "Got error while downloading on byte %d.\n", count );
      exit(0);
    } /* if */
    
    /* bizarrity #2935: MSB and LSB are mixed up in Xilinx world */
    outb( (char) flip_byte(c) & 0xFF, LP1_DR );

#if SSTEP
    printf( "Data now available: %X.\n", c & 0xFF );
    getchar();
#endif

    /* send the byte to the FPGA */
    one_byte();
    
    /* martching .'s to monitor progress */
    if( !(count % 1024) ) {
      /* printf( "count: %d\n", count ); */
      printf( "." );
      fflush(stdout);   /* in case of buffered I/O */
    } /* if */

  } /* while */

  outb( (char) (inb( LP1_CR )  | CR_STB) & 0xFF, LP1_CR );

  printf( "\nuploaded %d bytes\n", count );

} /* main */


void init_ports() {
  /* init_ports */
  /* locals */

  /* body */
  
  /* if in linux mode, enable access to the parallel port I/O space.
	 you must be superuser to do this. */

#ifdef LINUX
  ioperm((unsigned long) LP1_BASE, (unsigned long) 0x3, 0x2 );
#endif

} /* init_ports */



static int flip_byte(int byte)
{ /* flip_byte */
  int bit=0, result = 0;
  
  for (bit = 0; bit < 8; bit++)
    if (byte & (1 << bit))
      result |= (1 << (7 - bit));
  
  return (result);
} /* flip_bypte */



void frob_cclk() {
  /* frob_cclk */
  /* locals */
  long wait;

  /* body */
  outb( (char) (inb( LP1_CR ) & ~CR_STB) & 0xFF, LP1_CR );
#if SSTEP
    printf( "strobe is now high\n" );
    getchar();
#endif

  for( wait = 0; wait < WAIT; wait++ )
	;
  outb( (char) (inb( LP1_CR )  | CR_STB) & 0xFF, LP1_CR );
#if SSTEP
    printf( "strobe is now low\n" );
    getchar();
#endif
  for( wait = 0; wait < WAIT; wait++ )
	;

} /* frob_cclk */



void one_byte() {
  /* one_byte */
  /* locals */
  int i;

  /* body */
  for( i = 0 ; i < 8; i++ )
    frob_cclk();
} /* one_byte */



void print_banner() {
  /* print_banner */
  /* locals */

  /* body */
  printf( "upload v2.0b (1/23/98)\n" );

} /* print_banner */