1.\" $NetBSD: com.4,v 1.14 2009/05/13 12:40:37 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Systems Programming Group of the University of Utah Computer 8.\" Science Department. 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91 34.\" 35.Dd June 1, 2007 36.Dt COM 4 37.Os 38.Sh NAME 39.Nm com 40.Nd serial communications interface 41.Sh SYNOPSIS 42.Cd "com0 at isa? port" \&"IO_COM1\&" irq 4 43.Cd "com1 at isa? port" \&"IO_COM2\&" irq 3 44.Cd "com* at acpi?" 45.Cd "com* at cardbus?" 46.Cd "com* at isapnp?" 47.Cd "com* at mca? slot ?" 48.Cd "com* at mhzc?" 49.Cd "com* at ofisa?" 50.Cd "com* at pcmcia?" 51.Cd "com* at pcmcom?" 52.Cd "com* at pnpbios? index ?" 53.Cd "com* at puc? port ?" 54.Cd "com* at xirc?" 55.Cd options COM_HAYESP 56.Cd options RND_COM 57.Ss Arm32 58.Cd "com0 at mainbus? base 0x00210fe0" 59.Cd "com1 at mainbus? base 0x00210be0" 60.Ss HP 9000/300 and 400 Series 61.Cd "com* at dio? scode ?" 62.Cd "com* at frodo? offset ?" 63.Ss IBM PowerPC 4xx 64.Cd "com* at opb?" 65.Ss SPARC 66.Cd "com* at ebus?" 67.Cd "com* at obio0" 68.Sh DESCRIPTION 69The 70.Nm 71driver provides support for NS8250-, NS16450-, and NS16550-based 72.Tn EIA 73.Tn RS-232C 74.Pf ( Tn CCITT 75.Tn V.28 ) 76communications interfaces. 77The NS8250 and NS16450 have single character 78buffers, and the NS16550 has a 16 character buffer. 79.Pp 80Input and output for each line may set to one of following baud rates; 8150, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 8219200, 38400, 57600, or 115200, or any other baud rate which is a factor 83of 115200. 84.Pp 85The ttyXX devices are traditional dial-in devices; the dtyXX devices are 86used for dial-out. 87(See 88.Xr tty 4 . ) 89.Pp 90.Cd options COM_HAYESP 91adds support for the Hayes ESP serial board. 92.Pp 93With 94.Cd options RND_COM 95enabled, the 96.Nm 97driver can be used to collect entropy for the 98.Xr rnd 4 99entropy pool. 100The entropy is generated from interrupt randomness. 101.Ss Arm32 specific 102If 103.Dq flags 1 104is specified, the 105.Nm 106driver will not set the 107.Dv MCR_IENABLE 108bit on the UART. 109This is mainly for use on AST multiport boards, where the 110.Dv MCR_IENABLE 111bit is used to control whether or not the devices use a shared 112interrupt. 113.Sh FILES 114.Bl -tag -width Pa -compact 115.It Pa /dev/dty00 116.It Pa /dev/dty01 117.It Pa /dev/dty02 118.It Pa /dev/tty00 119.It Pa /dev/tty01 120.It Pa /dev/tty02 121.El 122.Sh DIAGNOSTICS 123.Bl -diag 124.It com%d: %d silo overflows 125The input 126.Dq silo 127has overflowed and incoming data has been lost. 128.It com%d: weird interrupt: iir=%x 129The device has generated an unexpected interrupt 130with the code listed. 131.El 132.Sh SEE ALSO 133.Xr acpi 4 , 134.Xr ast 4 , 135.Xr cardbus 4 , 136.Xr isa 4 , 137.Xr isapnp 4 , 138.Xr mca 4 , 139.Xr mhzc 4 , 140.Xr ofisa 4 , 141.Xr pcmcia 4 , 142.Xr pcmcom 4 , 143.Xr pnpbios 4 , 144.Xr puc 4 , 145.Xr rtfps 4 , 146.Xr tty 4 , 147.Xr xirc 4 148.Sh HISTORY 149The 150.Nm 151driver was originally derived from the HP9000/300 152.Ic dca 153driver. 154.Sh BUGS 155Data loss is possible on busy systems with unbuffered UARTs at high speed. 156.Pp 157The name of this driver and the constants which define the locations 158of the various serial ports are holdovers from 159.Tn DOS . 160