156 lines
5.8 KiB
Groff
156 lines
5.8 KiB
Groff
.\" $NetBSD: scn.4,v 1.1 1997/09/30 04:50:58 phil Exp $
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.\"
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.\" Copyright (c) 1997 Philip L. Budne.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by Philip L. Budne.
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.\" 3. The name of the author may not be used to endorse or promote products
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.\" derived from this software without specific prior written permission
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\"
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.Dd June 27, 1997
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.Dt SCN 4 pc532
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.Os NetBSD 1.2
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.Sh NAME
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.Nm scn
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.Nd
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Signetics serial communications interface
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.Sh SYNOPSIS
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.Cd "scn0 at mainbus? flags 0x1"
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.Cd "scn1 at mainbus? flags 0x0"
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.Cd "scn2 at mainbus? flags 0x0"
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.Cd "scn3 at mainbus? flags 0x0"
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.Cd "scn4 at mainbus? flags 0x0"
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.Cd "scn5 at mainbus? flags 0x0"
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.Cd "scn6 at mainbus? flags 0x0"
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.Cd "scn7 at mainbus? flags 0x0"
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.Sh DESCRIPTION
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The
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.Nm
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driver provides support for Signetics SCN2681, SCN2692, and SC26C92
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.Tn EIA
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.Tn RS-232C
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.Pf ( Tn CCITT
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.Tn V.28 )
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DUARTs on the pc532. The MC68681 DUART and SCC2698 OCTART are
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similar. The SCN2681 and SCN2692 have 3 character FIFOs; the SC26C92
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has a 16-character FIFO.
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.Pp
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Separate speeds for input and output are supported on each line. The
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SCN2681 and SCN2692 baud rate generator (BRG) supports the following
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speeds; 50, 75, 110, 134.5, 150, 200, 300, 600, 1050, 1200, 1800,
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2000, 2400, 4800, 7200, 9600, 19200, and 38400 bits per second.
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However, because the BRG table has two seperate columns of 16 speeds,
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and the table in use is shared between the input and output sides of
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the two channels, not all speeds are available at all times. The
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Counter/Timer will be used, when available to generate additional,
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arbitrary speeds upto 57600 bps but only one C/T is present in each
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DUART.
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.Pp
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The SC26C92 DUART adds two additional BRG modes (each containing two
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16 entry tables with two columns) supporting additional speeds of 450,
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880, 900, 1076, 3600, 14400, 28800, 57600, 115200, and 230400 bits per
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second (as well as some of the speeds listed above).
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.Pp
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Opens on tty0? (dialin) devices will wait for the presence of carrier
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detect and are generally used in the /etc/ttys file. Opens on cu0?
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(callout) devices will succeed when carrier is not present and are
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meant for use for dialing out on a modem (for ppp, tip, kermit, etc).
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Dialout opens when the dialin device is in use will fail with EBUSY.
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Dialin opens with O_NONBLOCK will fail with EBUSY if the line is in
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use for dialout. Other opens will wait until the line is available.
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.Pp
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An optional config file argument
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.Ar flags
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is supported with the following valued OR-ed together;
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.Bl -tag -width 0x4 -offset indent
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.It 0x1
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Sets software carrier (SOFTCAR); The line will be treated as
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hard-wired, with carrier always present. DTR is not dropped on close.
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.It 0x2
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Sets local line (CLOCAL). Opens will not wait for carrier.
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.It 0x4
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Sets RTS/CTS hardware flow control (CRTSCTS).
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.It 0x8
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Sets DTR/DCD hardware flow control (MDMBUF). [Not yet implemented].
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.El
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.Pp
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Various config options exist for the
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.Nm
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driver;
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.Bl -hang -width xxxxxxxxxx -offset indent
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.It Cd options SCN_TIMING
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.br
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Keep information on latency from time of character input
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in special rxintr routine to time of soft interrupt.
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.It Cd options CONSOLE_SPEED=Bnnn
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.br
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Sets console speed independant of default speed for other ttys.
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.It Cd options SCNDEF_CFLAG="CREAD+CS8+HUPCL"
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.br
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Sets default flags for scn tty lines.
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.El
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.Sh FILES
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.Bl -tag -width Pa
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.It Pa /dev/tty0?
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.It Pa /dev/cu0?
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.El
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.Sh DIAGNOSTICS
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.Pp
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.\" talk about reasons!!
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.Bl -diag
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.It scn%d: fifo overrun
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The hardware FIFO in the chip has been overrun.
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.It scn%d: ring overrun
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The internal ring-buffer used to hold characters until a software
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interrupt service routine runs to process the characters has overflowed.
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.El
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.Sh SEE ALSO
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.Xr termios 4 ,
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.Xr tty 4
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.Sh HISTORY
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The
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.Nm
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driver first appeared in
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.Nx 0.9 .
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Original version by Philip Nelson (starting with Minix driver by Philip
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Nelson), majorly mangled by Phil Budne (using ideas and code from Dave
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Rand and Chris Torek). Improvements by Ian Dall and Matthias Pfaller.
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.Sh BUGS
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Configuration should be done on two levels: DUARTs and TTYs.
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.Pp
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DUART configuration should take duart address in I/O region.
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.Pp
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TTY configuration should take duart, port number and flags.
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.Pp
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Some sequences of default tty speeds, opening ports and setting speeds
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may work, while others may not, due to the limitations of the chips.
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.Pp
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The driver should reset SC26C92's to mode 0 on shutdown since the
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pc532 monitor PROM does not know about the additional BRG modes.
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.Pp
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The SOFTCAR flag forced on for the console line.
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