1.\" $NetBSD: com.4,v 1.16 2010/05/31 09:30:55 skrll 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 May 31, 2010 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 HP 9000/700 and 800 Series 64.Cd "com* at dino?" 65.Cd "com* at gsc?" 66.Cd "com* at ssio?" 67.Ss IBM PowerPC 4xx 68.Cd "com* at opb?" 69.Ss SPARC 70.Cd "com* at ebus?" 71.Cd "com* at obio0" 72.Sh DESCRIPTION 73The 74.Nm 75driver provides support for NS8250-, NS16450-, and NS16550-based 76.Tn EIA 77.Tn RS-232C 78.Pf ( Tn CCITT 79.Tn V.28 ) 80communications interfaces. 81The NS8250 and NS16450 have single character 82buffers, and the NS16550 has a 16 character buffer. 83.Pp 84Input and output for each line may set to one of following baud rates; 8550, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 8619200, 38400, 57600, or 115200, or any other baud rate which is a factor 87of 115200. 88.Pp 89The ttyXX devices are traditional dial-in devices; the dtyXX devices are 90used for dial-out. 91(See 92.Xr tty 4 . ) 93.Pp 94.Cd options COM_HAYESP 95adds support for the Hayes ESP serial board. 96.Pp 97With 98.Cd options RND_COM 99enabled, the 100.Nm 101driver can be used to collect entropy for the 102.Xr rnd 4 103entropy pool. 104The entropy is generated from interrupt randomness. 105.Ss Arm32 specific 106If 107.Dq flags 1 108is specified, the 109.Nm 110driver will not set the 111.Dv MCR_IENABLE 112bit on the UART. 113This is mainly for use on AST multiport boards, where the 114.Dv MCR_IENABLE 115bit is used to control whether or not the devices use a shared 116interrupt. 117.Sh FILES 118.Bl -tag -width Pa -compact 119.It Pa /dev/dty00 120.It Pa /dev/dty01 121.It Pa /dev/dty02 122.It Pa /dev/tty00 123.It Pa /dev/tty01 124.It Pa /dev/tty02 125.El 126.Sh DIAGNOSTICS 127.Bl -diag 128.It com%d: %d silo overflows 129The input 130.Dq silo 131has overflowed and incoming data has been lost. 132.It com%d: weird interrupt: iir=%x 133The device has generated an unexpected interrupt 134with the code listed. 135.El 136.Sh SEE ALSO 137.Xr acpi 4 , 138.Xr ast 4 , 139.Xr cardbus 4 , 140.Xr isa 4 , 141.Xr isapnp 4 , 142.Xr mca 4 , 143.Xr mhzc 4 , 144.Xr ofisa 4 , 145.Xr pcmcia 4 , 146.Xr pcmcom 4 , 147.Xr pnpbios 4 , 148.Xr puc 4 , 149.Xr rtfps 4 , 150.Xr tty 4 , 151.Xr xirc 4 152.Sh HISTORY 153The 154.Nm 155driver was originally derived from the HP9000/300 156.Ic dca 157driver. 158.Sh BUGS 159Data loss is possible on busy systems with unbuffered UARTs at high speed. 160.Pp 161The name of this driver and the constants which define the locations 162of the various serial ports are holdovers from 163.Tn DOS . 164