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/*
Copyright (C) 2000-2001 Jos 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--;
}
}
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