423 lines
13 KiB
Groff
423 lines
13 KiB
Groff
.\" 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. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. 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: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd October 17, 2004
|
|
.Dt SIO 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm sio
|
|
.Nd "fast interrupt driven asynchronous serial communications interface"
|
|
.Sh SYNOPSIS
|
|
For standard ISA ports:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "device sio"
|
|
.Pp
|
|
In
|
|
.Pa /boot/device.hints :
|
|
.Cd hint.sio.0.at="isa"
|
|
.Cd hint.sio.0.port="0x3f8"
|
|
.Cd hint.sio.0.flags="0x10"
|
|
.Cd hint.sio.0.irq="4"
|
|
.Cd hint.sio.1.at="isa"
|
|
.Cd hint.sio.1.port="0x2f8"
|
|
.Cd hint.sio.1.flags="0x0"
|
|
.Cd hint.sio.1.irq="3"
|
|
.Ed
|
|
.Pp
|
|
For AST compatible multiport cards with 4 ports:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "options COM_MULTIPORT"
|
|
.Cd "device sio"
|
|
.Pp
|
|
In
|
|
.Pa /boot/device.hints :
|
|
.Cd hint.sio.4.at="isa"
|
|
.Cd hint.sio.4.port="0x2a0"
|
|
.Cd hint.sio.4.flags="0x701"
|
|
.Cd hint.sio.5.at="isa"
|
|
.Cd hint.sio.5.port="0x2a8"
|
|
.Cd hint.sio.5.flags="0x701"
|
|
.Cd hint.sio.6.at="isa"
|
|
.Cd hint.sio.6.port="0x2b0"
|
|
.Cd hint.sio.6.flags="0x701"
|
|
.Cd hint.sio.7.at="isa"
|
|
.Cd hint.sio.7.port="0x2b8"
|
|
.Cd hint.sio.7.flags="0x701"
|
|
.Cd hint.sio.7.irq="12"
|
|
.Ed
|
|
.Pp
|
|
For Boca Board compatible multiport cards with 8 ports:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "options COM_MULTIPORT"
|
|
.Cd "device sio"
|
|
.Pp
|
|
In
|
|
.Pa /boot/device.hints :
|
|
.Cd hint.sio.4.at="isa"
|
|
.Cd hint.sio.4.port="0x100"
|
|
.Cd hint.sio.4.flags="0xb05"
|
|
.Cd "..."
|
|
.Cd hint.sio.11.at="isa"
|
|
.Cd hint.sio.11.port="0x138"
|
|
.Cd hint.sio.11.flags="0xb05"
|
|
.Cd hint.sio.11.irq="12"
|
|
.Ed
|
|
.Pp
|
|
For Netmos Nm9845 multiport cards with 6 ports:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "options COM_MULTIPORT"
|
|
.Cd "device sio"
|
|
.Pp
|
|
In
|
|
.Pa /boot/device.hints :
|
|
.Cd hint.sio.4.at="isa"
|
|
.Cd hint.sio.4.port="0xb000"
|
|
.Cd hint.sio.4.flags="0x901"
|
|
.Cd hint.sio.5.at="isa"
|
|
.Cd hint.sio.5.port="0xb400"
|
|
.Cd hint.sio.5.flags="0x901"
|
|
.Cd hint.sio.6.at="isa"
|
|
.Cd hint.sio.6.port="0xb800"
|
|
.Cd hint.sio.6.flags="0x901"
|
|
.Cd hint.sio.7.at="isa"
|
|
.Cd hint.sio.7.port="0xbc00"
|
|
.Cd hint.sio.7.flags="0x901"
|
|
.Cd hint.sio.8.at="isa"
|
|
.Cd hint.sio.8.port="0xc000"
|
|
.Cd hint.sio.8.flags="0x901"
|
|
.Cd hint.sio.9.at="isa"
|
|
.Cd hint.sio.9.port="0xac00"
|
|
.Cd hint.sio.9.flags="0x901"
|
|
.Cd hint.sio.9.irq="12"
|
|
.Ed
|
|
.Pp
|
|
For Hayes ESP cards:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "options COM_ESP"
|
|
.Cd "device sio"
|
|
.Cd "..."
|
|
.Ed
|
|
.Pp
|
|
For single port PCI and PCCARD cards:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "device sio"
|
|
.Pp
|
|
No lines are required in
|
|
.Pa /boot/device.hints
|
|
for these cards.
|
|
.Ed
|
|
.Pp
|
|
For dual port PCI cards that share an interrupt:
|
|
.Bd -ragged -offset indent -compact
|
|
.Cd "device sio"
|
|
.Cd "options COM_MULTIPORT"
|
|
.Pp
|
|
In
|
|
.Pa /boot/device.hints :
|
|
.Cd hint.sio.2.flags="0x201"
|
|
.Cd hint.sio.3.flags="0x201"
|
|
.Ed
|
|
.Pp
|
|
Meaning of
|
|
.Ar flags :
|
|
.Bl -tag -offset indent -compact -width 0x000000
|
|
.It 0x00001
|
|
shared IRQs
|
|
.It 0x00002
|
|
disable FIFO
|
|
.It 0x00004
|
|
no AST/4 compatible IRQ control register
|
|
.It 0x00008
|
|
recover sooner from lost output interrupts
|
|
.It 0x00010
|
|
device is potential system console
|
|
.It 0x00020
|
|
device is forced to become system console
|
|
.It 0x00040
|
|
device is reserved for low-level IO (e.g.\& for remote kernel debugging)
|
|
.It 0x00080
|
|
use this port for remote kernel debugging
|
|
.It 0x0 Ns Em ?? Ns 00
|
|
minor number of master port
|
|
.It 0x10000
|
|
PPS timestamping on CTS instead of DCD
|
|
.It 0x20000
|
|
device is assumed to use a 16650A-type (extended FIFO) chip
|
|
.El
|
|
.Pp
|
|
Minor numbering:
|
|
.Bd -literal -offset indent -compact
|
|
0b\fIOLIMMMMM\fR
|
|
call\fBO\fRut
|
|
\fBL\fRock
|
|
\fBI\fRnitial
|
|
\fBMMMMM\fRinor
|
|
.Ed
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver provides support for NS8250-, NS16450-, NS16550 and NS16550A-based
|
|
.Tn EIA
|
|
.Tn RS-232C
|
|
.Pf ( Tn CCITT
|
|
.Tn V.24 )
|
|
communications interfaces.
|
|
The NS8250 and NS16450 have single character
|
|
buffers, the NS16550A has 16 character FIFO input and output buffers.
|
|
.Pp
|
|
Input and output for each line may set to one of following baud rates;
|
|
50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600,
|
|
19200, 28800, 38400, 57600, or 115200.
|
|
Your hardware may limit your baud rate choices.
|
|
.Pp
|
|
The driver supports `multiport' cards.
|
|
Multiport cards are those that have one or more groups of ports
|
|
that share an Interrupt Request (IRQ) line per group.
|
|
Shared IRQs on different cards are not supported.
|
|
Frequently 4 ports share 1 IRQ; some 8 port cards have 2 groups of 4 ports,
|
|
thus using 2 IRQs.
|
|
Some cards allow the first 2 serial ports to have separate IRQs per port
|
|
(as per DOS PC standard).
|
|
.Pp
|
|
Some cards have an IRQ control register for each group.
|
|
Some cards require special initialization related to such registers.
|
|
Only AST/4 compatible IRQ control registers are supported.
|
|
Some cards have an IRQ status register for each group.
|
|
The driver does not require or use such registers yet.
|
|
To work, the control and status registers for a group, if any,
|
|
must be mapped to the scratch register (register 7)
|
|
of a port in the group.
|
|
Such a port is called a
|
|
.Em master
|
|
port.
|
|
.Pp
|
|
The driver supports controller based PCI modems.
|
|
The 3Com FaxModem PCI and the Advantec 56k Voice Messaging PCI
|
|
FaxModem are the only cards supported.
|
|
WinModems, softmodems, hfc modems and any other modems that aren't
|
|
controller based are not supported.
|
|
.Pp
|
|
The
|
|
.Em flags
|
|
keyword may be used on each
|
|
.Em device sio
|
|
line in the kernel configuration file
|
|
to disable the FIFO on 16550A UARTs
|
|
(see the synopsis).
|
|
Disabling the FIFO should rarely be necessary.
|
|
.Pp
|
|
The
|
|
.Em flags
|
|
keyword
|
|
.Em must
|
|
be used for all ports that are part of an IRQ sharing group.
|
|
One bit specifies IRQ sharing; another bit specifies whether the port does
|
|
.Em not
|
|
require AST/4 compatible initialization.
|
|
The minor number of the device corresponding a master port
|
|
for the group is encoded as a bitfield in the high byte.
|
|
The same master port must be specified for all ports in a group.
|
|
.Pp
|
|
The
|
|
.Em irq
|
|
specification must be given for master ports
|
|
and for ports that are not part of an IRQ sharing group,
|
|
and not for other ports.
|
|
.Pp
|
|
In the synopsis,
|
|
.Em flags 0x701
|
|
means that the 8th port (sio7) is the master
|
|
port, and that the port is on a multiport card with shared IRQs
|
|
and an AST/4 compatible IRQ control register.
|
|
.Pp
|
|
.Em flags 0xb05
|
|
means that the 12th port (sio11) is the master
|
|
port, and that the port is on a multiport card with shared IRQs
|
|
and no special IRQ control register.
|
|
.Pp
|
|
Which port is the master port depends on the card type.
|
|
Consult the hardware documentation of your card.
|
|
Since IRQ status registers are never used,
|
|
and IRQ control registers are only used for AST/4 compatible cards,
|
|
and some cards map the control/status registers to all ports in a group,
|
|
any port in a group will sometimes do for the master port.
|
|
Choose a port containing an IRQ status register for forwards compatibility,
|
|
and the highest possible port for consistency.
|
|
.Pp
|
|
Serial ports controlled by the
|
|
.Nm
|
|
driver can be used for both `callin' and `callout'.
|
|
For each port there is a callin device and a callout device.
|
|
The minor number of the callout device is 128 higher
|
|
than that of the corresponding callin port.
|
|
The callin device is general purpose.
|
|
Processes opening it normally wait for carrier
|
|
and for the callout device to become inactive.
|
|
The callout device is used to steal the port from
|
|
processes waiting for carrier on the callin device.
|
|
Processes opening it do not wait for carrier
|
|
and put any processes waiting for carrier on the callin device into
|
|
a deeper sleep so that they do not conflict with the callout session.
|
|
The callout device is abused for handling programs that are supposed
|
|
to work on general ports and need to open the port without waiting
|
|
but are too stupid to do so.
|
|
.Pp
|
|
The
|
|
.Nm
|
|
driver also supports an initial-state and a lock-state control
|
|
device for each of the callin and the callout "data" devices.
|
|
The minor number of the initial-state device is 32 higher
|
|
than that of the corresponding data device.
|
|
The minor number of the lock-state device is 64 higher
|
|
than that of the corresponding data device.
|
|
The termios settings of a data device are copied
|
|
from those of the corresponding initial-state device
|
|
on first opens and are not inherited from previous opens.
|
|
Use
|
|
.Xr stty 1
|
|
in the normal way on the initial-state devices to program
|
|
initial termios states suitable for your setup.
|
|
.Pp
|
|
The lock termios state acts as flags to disable changing
|
|
the termios state.
|
|
E.g., to lock a flag variable such as CRTSCTS, use
|
|
.Em stty crtscts
|
|
on the lock-state device.
|
|
Speeds and special characters
|
|
may be locked by setting the corresponding value in the lock-state
|
|
device to any nonzero value.
|
|
.Pp
|
|
Correct programs talking to correctly wired external devices
|
|
work with almost arbitrary initial states and almost no locking,
|
|
but other setups may benefit from changing some of the default
|
|
initial state and locking the state.
|
|
In particular, the initial states for non (POSIX) standard flags
|
|
should be set to suit the devices attached and may need to be
|
|
locked to prevent buggy programs from changing them.
|
|
E.g., CRTSCTS should be locked on for devices that support
|
|
RTS/CTS handshaking at all times and off for devices that don't
|
|
support it at all.
|
|
CLOCAL should be locked on for devices that don't support carrier.
|
|
HUPCL may be locked off if you don't
|
|
want to hang up for some reason.
|
|
In general, very bad things happen
|
|
if something is locked to the wrong state, and things should not
|
|
be locked for devices that support more than one setting.
|
|
The CLOCAL flag on callin ports should be locked off for logins
|
|
to avoid certain security holes, but this needs to be done by
|
|
getty if the callin port is used for anything else.
|
|
.Sh FILES
|
|
.Bl -tag -width /dev/ttyd?.init -compact
|
|
.It Pa /dev/ttyd?
|
|
for callin ports
|
|
.It Pa /dev/ttyd?.init
|
|
.It Pa /dev/ttyd?.lock
|
|
corresponding callin initial-state and lock-state devices
|
|
.Pp
|
|
.It Pa /dev/cuad?
|
|
for callout ports
|
|
.It Pa /dev/cuad?.init
|
|
.It Pa /dev/cuad?.lock
|
|
corresponding callout initial-state and lock-state devices
|
|
.El
|
|
.Pp
|
|
.Bl -tag -width /etc/rc.d/serial -compact
|
|
.It Pa /etc/rc.d/serial
|
|
examples of setting the initial-state and lock-state devices
|
|
.El
|
|
.Pp
|
|
The device numbers are made from the set [0-9a-v] so that more than
|
|
10 ports can be supported.
|
|
.Sh DIAGNOSTICS
|
|
.Bl -diag
|
|
.It sio%d: silo overflow.
|
|
Problem in the interrupt handler.
|
|
.El
|
|
.Bl -diag
|
|
.It sio%d: interrupt-level buffer overflow.
|
|
Problem in the bottom half of the driver.
|
|
.El
|
|
.Bl -diag
|
|
.It sio%d: tty-level buffer overflow.
|
|
Problem in the application.
|
|
Input has arrived faster than the given module could process it
|
|
and some has been lost.
|
|
.El
|
|
.\" .Bl -diag
|
|
.\" .It sio%d: reduced fifo trigger level to %d.
|
|
.\" Attempting to avoid further silo overflows.
|
|
.\" .El
|
|
.Sh SEE ALSO
|
|
.Xr stty 1 ,
|
|
.Xr termios 4 ,
|
|
.Xr tty 4 ,
|
|
.Xr comcontrol 8
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver is derived from the
|
|
.Tn HP9000/300
|
|
.Xr dca 4
|
|
driver and is
|
|
.Ud
|
|
.Sh BUGS
|
|
Data loss may occur at very high baud rates on slow systems,
|
|
or with too many ports on any system,
|
|
or on heavily loaded systems when crtscts cannot be used.
|
|
The use of NS16550A's reduces system load and helps to avoid data loss.
|
|
.Pp
|
|
Stay away from plain NS16550's.
|
|
These are early implementations of the chip with non-functional FIFO hardware.
|
|
.Pp
|
|
The constants which define the locations
|
|
of the various serial ports are holdovers from
|
|
.Tn DOS .
|
|
As shown, hex addresses can be and for clarity probably should be used instead.
|
|
.Pp
|
|
Note that on the AST/4 the card's dipswitches should
|
|
.Em not
|
|
be set to use interrupt sharing.
|
|
AST/4-like interrupt sharing is only used when
|
|
.Em multiple
|
|
AST/4 cards are installed in the same system.
|
|
The
|
|
.Nm
|
|
driver does not support more than 1 AST/4 on one IRQ.
|
|
.Pp
|
|
The examples in the synopsis are too vendor-specific.
|