1.\" $NetBSD: com.4,v 1.15 2010/01/10 15:05:26 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 January 10, 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.Ss IBM PowerPC 4xx 67.Cd "com* at opb?" 68.Ss SPARC 69.Cd "com* at ebus?" 70.Cd "com* at obio0" 71.Sh DESCRIPTION 72The 73.Nm 74driver provides support for NS8250-, NS16450-, and NS16550-based 75.Tn EIA 76.Tn RS-232C 77.Pf ( Tn CCITT 78.Tn V.28 ) 79communications interfaces. 80The NS8250 and NS16450 have single character 81buffers, and the NS16550 has a 16 character buffer. 82.Pp 83Input and output for each line may set to one of following baud rates; 8450, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 8519200, 38400, 57600, or 115200, or any other baud rate which is a factor 86of 115200. 87.Pp 88The ttyXX devices are traditional dial-in devices; the dtyXX devices are 89used for dial-out. 90(See 91.Xr tty 4 . ) 92.Pp 93.Cd options COM_HAYESP 94adds support for the Hayes ESP serial board. 95.Pp 96With 97.Cd options RND_COM 98enabled, the 99.Nm 100driver can be used to collect entropy for the 101.Xr rnd 4 102entropy pool. 103The entropy is generated from interrupt randomness. 104.Ss Arm32 specific 105If 106.Dq flags 1 107is specified, the 108.Nm 109driver will not set the 110.Dv MCR_IENABLE 111bit on the UART. 112This is mainly for use on AST multiport boards, where the 113.Dv MCR_IENABLE 114bit is used to control whether or not the devices use a shared 115interrupt. 116.Sh FILES 117.Bl -tag -width Pa -compact 118.It Pa /dev/dty00 119.It Pa /dev/dty01 120.It Pa /dev/dty02 121.It Pa /dev/tty00 122.It Pa /dev/tty01 123.It Pa /dev/tty02 124.El 125.Sh DIAGNOSTICS 126.Bl -diag 127.It com%d: %d silo overflows 128The input 129.Dq silo 130has overflowed and incoming data has been lost. 131.It com%d: weird interrupt: iir=%x 132The device has generated an unexpected interrupt 133with the code listed. 134.El 135.Sh SEE ALSO 136.Xr acpi 4 , 137.Xr ast 4 , 138.Xr cardbus 4 , 139.Xr isa 4 , 140.Xr isapnp 4 , 141.Xr mca 4 , 142.Xr mhzc 4 , 143.Xr ofisa 4 , 144.Xr pcmcia 4 , 145.Xr pcmcom 4 , 146.Xr pnpbios 4 , 147.Xr puc 4 , 148.Xr rtfps 4 , 149.Xr tty 4 , 150.Xr xirc 4 151.Sh HISTORY 152The 153.Nm 154driver was originally derived from the HP9000/300 155.Ic dca 156driver. 157.Sh BUGS 158Data loss is possible on busy systems with unbuffered UARTs at high speed. 159.Pp 160The name of this driver and the constants which define the locations 161of the various serial ports are holdovers from 162.Tn DOS . 163