freebsd-dev/sys/i386/boot/biosboot/probe_keyboard.c

116 lines
3.3 KiB
C

/*-
* Copyright (c) 1997 Kazutaka YOKOTA (yokota@zodiac.mech.utsunomiya-u.ac.jp)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: probe_keyboard.c,v 1.13 1997/06/09 05:10:55 bde Exp $
*/
#include <sys/types.h>
#include <machine/cpufunc.h>
#include <i386/isa/isa.h>
#include <dev/kbd/atkbdcreg.h>
#include "boot.h"
#define PROBE_MAXRETRY 5
#define PROBE_MAXWAIT 400
#define IO_DUMMY 0x84
/* 7 microsec delay necessary for some keyboard controllers */
static void
delay7(void)
{
/*
* I know this is broken, but no timer is avaiable yet at this stage...
* See also comments in `delay1ms()' in `io.c'.
*/
inb(IO_DUMMY); inb(IO_DUMMY);
inb(IO_DUMMY); inb(IO_DUMMY);
inb(IO_DUMMY); inb(IO_DUMMY);
}
/*
* Perform a simple test on the keyboard; issue the ECHO command and see
* if the right answer is returned. We don't do anything as drastic as
* full keyboard reset; it will be too troublesome and take too much time.
*/
int
probe_keyboard(void)
{
int retry = PROBE_MAXRETRY;
int wait;
int i;
while (--retry >= 0) {
/* flush any noise */
while (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL) {
delay7();
inb(IO_KBD + KBD_DATA_PORT);
delay1ms();
}
/* wait until the controller can accept a command */
for (wait = PROBE_MAXWAIT; wait > 0; --wait) {
if (((i = inb(IO_KBD + KBD_STATUS_PORT))
& (KBDS_INPUT_BUFFER_FULL | KBDS_ANY_BUFFER_FULL)) == 0)
break;
if (i & KBDS_ANY_BUFFER_FULL) {
delay7();
inb(IO_KBD + KBD_DATA_PORT);
}
delay1ms();
}
if (wait <= 0)
continue;
/* send the ECHO command */
outb(IO_KBD + KBD_DATA_PORT, KBDC_ECHO);
/* wait for a response */
for (wait = PROBE_MAXWAIT; wait > 0; --wait) {
if (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL)
break;
delay1ms();
}
if (wait <= 0)
continue;
delay7();
i = inb(IO_KBD + KBD_DATA_PORT);
#ifdef PROBE_KBD_BEBUG
printf("probe_keyboard: got 0x%x.\n", i);
#endif
if (i == KBD_ECHO) {
/* got the right answer */
return (0);
}
}
return (1);
}