comconsole.c revision 120118 
1/*
2 * Copyright (c) 1998 Michael Smith (msmith@freebsd.org)
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD: head/sys/boot/pc98/libpc98/comconsole.c 120118 2003-09-16 11:24:23Z bde $");
28
29#include <stand.h>
30#include <bootstrap.h>
31#include <machine/cpufunc.h>
32#include <dev/ic/ns16550.h>
33#include "libi386.h"
34
35#define COMC_FMT	0x3		/* 8N1 */
36#define COMC_TXWAIT	0x40000		/* transmit timeout */
37#define COMC_BPS(x)	(115200 / (x))	/* speed to DLAB divisor */
38
39#ifndef	COMPORT
40#ifdef PC98
41#define COMPORT		0x238
42#else
43#define COMPORT		0x3f8
44#endif
45#endif
46#ifndef	COMSPEED
47#define COMSPEED	9600
48#endif
49
50static void	comc_probe(struct console *cp);
51static int	comc_init(int arg);
52static void	comc_putchar(int c);
53static int	comc_getchar(void);
54static int	comc_ischar(void);
55
56static int	comc_started;
57
58struct console comconsole = {
59    "comconsole",
60    "serial port",
61    0,
62    comc_probe,
63    comc_init,
64    comc_putchar,
65    comc_getchar,
66    comc_ischar
67};
68
69static void
70comc_probe(struct console *cp)
71{
72    /* XXX check the BIOS equipment list? */
73    cp->c_flags |= (C_PRESENTIN | C_PRESENTOUT);
74}
75
76static int
77comc_init(int arg)
78{
79    if (comc_started && arg == 0)
80	return 0;
81    comc_started = 1;
82
83    outb(COMPORT + com_cfcr, CFCR_DLAB | COMC_FMT);
84    outb(COMPORT + com_dlbl, COMC_BPS(COMSPEED) & 0xff);
85    outb(COMPORT + com_dlbh, COMC_BPS(COMSPEED) >> 8);
86    outb(COMPORT + com_cfcr, COMC_FMT);
87    outb(COMPORT + com_mcr, MCR_RTS | MCR_DTR);
88
89    do
90        inb(COMPORT + com_data);
91    while (inb(COMPORT + com_lsr) & LSR_RXRDY);
92
93    return(0);
94}
95
96static void
97comc_putchar(int c)
98{
99    int wait;
100
101    for (wait = COMC_TXWAIT; wait > 0; wait--)
102        if (inb(COMPORT + com_lsr) & LSR_TXRDY) {
103	    outb(COMPORT + com_data, (u_char)c);
104	    break;
105	}
106}
107
108static int
109comc_getchar(void)
110{
111    return(comc_ischar() ? inb(COMPORT + com_data) : -1);
112}
113
114static int
115comc_ischar(void)
116{
117    return(inb(COMPORT + com_lsr) & LSR_RXRDY);
118}
119