freebsd-skq/sys/boot/i386/libi386/comconsole.c

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/*
* Copyright (c) 1998 Michael Smith (msmith@freebsd.org)
*
* 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.
*
1999-08-28 01:08:13 +00:00
* $FreeBSD$
*/
#include <stand.h>
#include <bootstrap.h>
#include <machine/cpufunc.h>
#include "libi386.h"
/* selected defines from ns16550.h */
#define com_data 0 /* data register (R/W) */
#define com_dlbl 0 /* divisor latch low (W) */
#define com_dlbh 1 /* divisor latch high (W) */
#define com_ier 1 /* interrupt enable (W) */
#define com_iir 2 /* interrupt identification (R) */
#define com_fifo 2 /* FIFO control (W) */
#define com_lctl 3 /* line control register (R/W) */
#define com_cfcr 3 /* line control register (R/W) */
#define com_mcr 4 /* modem control register (R/W) */
#define com_lsr 5 /* line status register (R/W) */
#define com_msr 6 /* modem status register (R/W) */
/* selected defines from sioreg.h */
#define CFCR_DLAB 0x80
#define MCR_RTS 0x02
#define MCR_DTR 0x01
#define LSR_TXRDY 0x20
#define LSR_RXRDY 0x01
#define COMC_FMT 0x3 /* 8N1 */
#define COMC_TXWAIT 0x40000 /* transmit timeout */
#define COMC_BPS(x) (115200 / (x)) /* speed to DLAB divisor */
#ifndef COMPORT
#define COMPORT 0x3f8
#endif
#ifndef COMSPEED
#define COMSPEED 9600
#endif
static void comc_probe(struct console *cp);
static int comc_init(int arg);
static void comc_putchar(int c);
static int comc_getchar(void);
static int comc_ischar(void);
static int comc_started;
struct console comconsole = {
"comconsole",
"serial port",
0,
comc_probe,
comc_init,
comc_putchar,
comc_getchar,
comc_ischar
};
static void
comc_probe(struct console *cp)
{
/* XXX check the BIOS equipment list? */
cp->c_flags |= (C_PRESENTIN | C_PRESENTOUT);
}
static int
comc_init(int arg)
{
if (comc_started && arg == 0)
return 0;
comc_started = 1;
outb(COMPORT + com_cfcr, CFCR_DLAB | COMC_FMT);
outb(COMPORT + com_dlbl, COMC_BPS(COMSPEED) & 0xff);
outb(COMPORT + com_dlbh, COMC_BPS(COMSPEED) >> 8);
outb(COMPORT + com_cfcr, COMC_FMT);
outb(COMPORT + com_mcr, MCR_RTS | MCR_DTR);
do
inb(COMPORT + com_data);
while (inb(COMPORT + com_lsr) & LSR_RXRDY);
return(0);
}
static void
comc_putchar(int c)
{
int wait;
for (wait = COMC_TXWAIT; wait > 0; wait--)
if (inb(COMPORT + com_lsr) & LSR_TXRDY) {
outb(COMPORT + com_data, (u_char)c);
break;
}
}
static int
comc_getchar(void)
{
return(comc_ischar() ? inb(COMPORT + com_data) : -1);
}
static int
comc_ischar(void)
{
return(inb(COMPORT + com_lsr) & LSR_RXRDY);
}