$OpenBSD: hsq.4,v 1.18 2018/01/03 08:43:09 bentley Exp $
from: OpenBSD: ast.4,v 1.5 1999/07/09 13:35:43 aaron Exp
from: NetBSD: ast.4,v 1.7 1996/03/16 00:07:07 thorpej Exp

Copyright (c) 1990, 1991 The Regents of the University of California.
All rights reserved.

This code is derived from software contributed to Berkeley by
the Systems Programming Group of the University of Utah Computer
Science Department.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

from: @(#)dca.4 5.2 (Berkeley) 3/27/91
from: Id: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp

.Dd $Mdocdate: February 20 2014 $ .Dt HSQ 4 .Os .Sh NAME .Nm hsq .Nd multiplexing serial communications interface .Sh SYNOPSIS .Cd "hsq0 at isa? port 0x140 irq 10" .Cd "com* at hsq?" .Sh DESCRIPTION The .Nm driver provides support for Hostess

q Lk https://www.comtrol.com/ "Comtrol Corporation" and compatible boards that multiplex together up to four .Tn EIA .Tn RS-232C

q Tn CCITT V.28 communications interfaces.

p Each .Nm device is the master device for up to four .Nm com devices. The kernel configuration specifies these .Nm com devices as slave devices of the .Nm device, as shown in .Sx SYNOPSIS . The slave ID given for each .Nm com device determines which bit in the interrupt multiplexing register is tested to find interrupts for that device. The .Cd port specification for the .Nm device is used to compute the base addresses for the .Nm com subdevices (they are equal to port + ID * 8) and the port for the interrupt multiplexing register (it is equal to port + 7). More technical details on how the driver works can be found in the big comment at the beginning of the driver's source code.

p Information on setup of card's configuration switches should be taken from Comtrol Corporation's web site, since the author wrote and tested the driver only with Hostess-compatible cards. .Sh FILES l -tag -width Pa -compact t Pa /dev/tty0? t Pa /dev/cua0? .El .Sh SEE ALSO .Xr com 4 , .Xr intro 4 , .Xr isa 4 .Sh HISTORY The .Nm driver was written by .An Denis A. Doroshenko based on the .Xr ast 4 driver.