comconsole.c revision 68358
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 * $FreeBSD: head/sys/boot/pc98/libpc98/comconsole.c 68358 2000-11-05 12:35:41Z nyan $ 26 */ 27 28#include <stand.h> 29#include <bootstrap.h> 30#include <machine/cpufunc.h> 31#include "libi386.h" 32 33/* selected defines from ns16550.h */ 34#define com_data 0 /* data register (R/W) */ 35#define com_dlbl 0 /* divisor latch low (W) */ 36#define com_dlbh 1 /* divisor latch high (W) */ 37#define com_ier 1 /* interrupt enable (W) */ 38#define com_iir 2 /* interrupt identification (R) */ 39#define com_fifo 2 /* FIFO control (W) */ 40#define com_lctl 3 /* line control register (R/W) */ 41#define com_cfcr 3 /* line control register (R/W) */ 42#define com_mcr 4 /* modem control register (R/W) */ 43#define com_lsr 5 /* line status register (R/W) */ 44#define com_msr 6 /* modem status register (R/W) */ 45 46/* selected defines from sioreg.h */ 47#define CFCR_DLAB 0x80 48#define MCR_RTS 0x02 49#define MCR_DTR 0x01 50#define LSR_TXRDY 0x20 51#define LSR_RXRDY 0x01 52 53#define COMC_FMT 0x3 /* 8N1 */ 54#define COMC_TXWAIT 0x40000 /* transmit timeout */ 55#define COMC_BPS(x) (115200 / (x)) /* speed to DLAB divisor */ 56 57#ifndef COMPORT 58#ifdef PC98 59#define COMPORT 0x238 60#else 61#define COMPORT 0x3f8 62#endif 63#endif 64#ifndef COMSPEED 65#define COMSPEED 9600 66#endif 67 68static void comc_probe(struct console *cp); 69static int comc_init(int arg); 70static void comc_putchar(int c); 71static int comc_getchar(void); 72static int comc_ischar(void); 73 74static int comc_started; 75 76struct console comconsole = { 77 "comconsole", 78 "serial port", 79 0, 80 comc_probe, 81 comc_init, 82 comc_putchar, 83 comc_getchar, 84 comc_ischar 85}; 86 87static void 88comc_probe(struct console *cp) 89{ 90 /* XXX check the BIOS equipment list? */ 91 cp->c_flags |= (C_PRESENTIN | C_PRESENTOUT); 92} 93 94static int 95comc_init(int arg) 96{ 97 if (comc_started && arg == 0) 98 return 0; 99 comc_started = 1; 100 101 outb(COMPORT + com_cfcr, CFCR_DLAB | COMC_FMT); 102 outb(COMPORT + com_dlbl, COMC_BPS(COMSPEED) & 0xff); 103 outb(COMPORT + com_dlbh, COMC_BPS(COMSPEED) >> 8); 104 outb(COMPORT + com_cfcr, COMC_FMT); 105 outb(COMPORT + com_mcr, MCR_RTS | MCR_DTR); 106 107 do 108 inb(COMPORT + com_data); 109 while (inb(COMPORT + com_lsr) & LSR_RXRDY); 110 111 return(0); 112} 113 114static void 115comc_putchar(int c) 116{ 117 int wait; 118 119 for (wait = COMC_TXWAIT; wait > 0; wait--) 120 if (inb(COMPORT + com_lsr) & LSR_TXRDY) { 121 outb(COMPORT + com_data, (u_char)c); 122 break; 123 } 124} 125 126static int 127comc_getchar(void) 128{ 129 return(comc_ischar() ? inb(COMPORT + com_data) : -1); 130} 131 132static int 133comc_ischar(void) 134{ 135 return(inb(COMPORT + com_lsr) & LSR_RXRDY); 136} 137