/*
Copyright (C) 2000-2001 José Roberto B. de A. Monteiro <jrm@autsens.com>
                        and Pedro Zorzenon Neto <pzn@autsens.com>

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

/*
 From http://www.linuxdoc.org/HOWTO/mini/IO-Port-Programming.html
 an outb to port 0x80 gives a delay of aprox 1microsec independent
 of your machine type/clock.
 See also documentation in asm/io.h
*/

#include "microdelay.h"
#include <unistd.h>
#include <sys/io.h>

int old_port_value;

void microdelay_init() {
    // permition to write in port 0x80
    // nothing is suposed to use this port
    // however, we will write the same value we read...
    ioperm(0x80,1,1);
    old_port_value=inb(0x80);
}

void microdelay(unsigned int microsec) {
    while (microsec)
    {
	outb(old_port_value,0x80);
	microsec--;
    }
}