/*============ pp_access.c =====================================

    See pp_access.h for details.          
*/

#include <stdio.h>
#include <unistd.h>
#include "pp_access.h"

/*-------- init() --------------------------------------------

  PURPOSE - given lp number 0-2, get lp base address, 
            save registers, disable interrupts.
*/
void lp_init(short lp_num) 
 { switch ( lp_num)
    { case 2 : lp_base_addr = 0x3BC ; break ;
      case 1 : lp_base_addr = 0x278 ; break ;
      default: lp_base_addr = 0x378 ; break ;
    } 
   image_data    = save_data    = inb( lp_base_addr) ;
   image_control = save_control = inb( lp_base_addr+2) ;
   outb( (image_control &= 0xEF),  lp_base_addr + control_offset) ;
 }

/*--------- lp_restore() ------------------------------------

  PURPOSE - restore lp port to previous state.
*/
void lp_restore()
{  outb( save_data,    lp_base_addr) ;
   outb( save_control, lp_base_addr + control_offset) ;
}

//---------------- lp_base -----------------------------------

int lp_base()
 { return( lp_base_addr);
 }

//--------- main : example code ------------------------------

/*
int main(int argc, char *argv[])
{ //--- save all registers and disable interrupts.
    lp_init( 0) ;

  //---  clear data bit 0 and set data bit 1, keep image updated.
    outb( (image_data &= 0xFE), lp_base_addr) ;
    outb( (image_data |= 0x02), lp_base_addr) ;
    printf("   Pin 2 (d0) is now low, pin 3 (d1) is now high.\n") ;

  //--- test if select or busy (inverted) is high.
    if ( inb( lp_base_addr+status_offset) & 0x10)
         printf("   Input bit select ( pin 13) is low.\n") ;
    else printf("   Input bit select ( pin 13) is high.\n") ;
    if ( inb( lp_base_addr+status_offset) & 0x80)
         printf("   Input bit busy ( pin 11) is high.\n") ;
    else printf("   Input bit busy ( pin 11) is low.\n") ;

  //--- pause till key pressed so can measure outputs.
    printf("   Press enter to continue ===> ") ;
    getchar() ; 

  //--- restore control and data registers and exit. 
    lp_restore() ;
    exit(0) ;
}
*/