si(4)

NAME

si - driver for Specialix International SI/XIO or SX intel

ligent serial
card

SYNOPSIS

device si
For   ISA   host   cards   put   the   following   lines  in
/boot/device.hints:
hint.si.0.at="isa"
hint.si.0.maddr="0xd0000"
hint.si.0.irq="12"

DESCRIPTION

The Specialix SI/XIO and SX hardware makes up an 8 to 32

port RS-232
serial multiplexor.

The system uses two components: a "Host adapter", which is

plugged into
an ISA, EISA or PCI slot and provides intelligence and

buffering/processing capabilities, as well as an external bus in the form of

a 37 pin
cable.

On this cable, "modules" are connected. The "SI" module

comes in a 4 and
8 port version. The "XIO" and "SX" modules come only in 8

port versions.

The host adapter polls and transfers data between the mod

ules and the
rest of the machine. The Host adapter provides a 256 byte

transmit and
256 byte receive FIFO for each of the 32 ports that it can

maintain.

The XIO modules can operate each of their 8 ports at 115,200

baud. The
SI version can run at 57,600 baud. The SX modules can oper

ate each of
their 8 ports at up to 921,600 baud.

SX modules are only supported when connected to an SX host

card. SI or
XIO modules are supported on any host card.

The host adapter uses a shared memory block in the tradi

tional ISA bus
"hole" between 0xA0000 and 0xEFFFF. The adapter can be con

figured outside range, but requires the memory range to be explicitly

non-cached.
The driver does not yet support this mode of operation.

SX ISA Host cards have an 8/16 bit mode switch or jumper on

them. This
switch or jumper MUST be set for 8 bit mode.

The ISA adapters can use Irq's 11, 12 or 15 (and 9 and 10 in

the case of
SX host cards).

The si device driver may have some of its configuration set

tings changed
at run-time with the sicontrol(8) utility.

The si device driver also responds to the comcontrol(8)

utility for configuring drain-on-close timeouts.

The driver also defines 3 sysctl variables that can be ma

nipulated:
machdep.si_debug sets the debug level for the whole driver.

It depends
on the driver being compiled with SI_DEBUG.

machdep.si_pollrate sets how
often per second the driver polls for lost interrupts.
machdep.si_realpoll sets whether or not the card will treat

the poll
intervals as if they were interrupts.

An open on a /dev device node controlled by the si driver

obeys the same
semantics as the sio(4) driver. It fully supports the usual

semantics of
the cua ports, and the "initial termios" and "locked

termios" settings.
In summary, an open on a tty port will block until DCD is

raised, unless
O_NONBLOCK is specified. CLOCAL is honored. An open on a

cua port will
always succeed, but DCD transitions will be honored after

DCD rises for
the first time.

Up to four SI/XIO host cards may be controlled by the si

driver. Due to
the lack of available interrupts, only 3 ISA SI/XIO host

cards can be
used at once.

The lowest 5 bits of the minor device number are used to se

lect the port
number on the module cluster. The next 2 bits select which

of 4 host
adapter cards. This allows a maximum of 128 ports on this

driver.

Bit 7 is used to differentiate a tty/dialin port (bit 7=0)

and a
cua/callout port (bit 7=1).

Bit 8 through 15 (on FreeBSD) are unavailable as they are a

shadow of the
major device number.

If bit 16 is a 1, the device node is referring to the "ini

tial state"
device. This "initial state" is used to prime the

termios(4) settings of
the device when it is initially opened. If bit 17 is a 1,

the device
node is referring to the "locked state" device. The "locked

state" is
used to prevent the termios(4) settings from being changed.

To manipulate the initial/locked settings, the stty(1) com

mand is useful.
When setting the "locked" variables, enabling the mode on

the lock device
will lock the termios mode, while disabling the mode will

unlock it.

FILES

/dev/si_control global driver control file for sicontrol(8)
/dev/ttyA* terminal/dialin ports
/dev/cuaA* dialout ports
/dev/ttyiA* initial termios state devices
/dev/ttylA* locked termios state devices
/dev/cuaiA* initial termios state devices for dialout

ports
/dev/cualA* locked termios state devices for dialout

ports

SEE ALSO

stty(1), sio(4), termios(4), tty(4), comcontrol(8), sicon

trol(8)

HISTORY

This driver is loosely based on driver code originating at

Specialix,
which was ported to run on BSDI by Andy Rutter <andy@spe

cialix.co.uk>.
The System V driver source is/was available by ftp from
ftp.specialix.co.uk.

This driver is not supported by Specialix International.

AUTHORS

Peter Wemm <peter@netplex.com.au> obtained the code from

Andy Rutter and
ported it to FreeBSD and threw the man page together. Bruce

Evans
<bde@zeta.org.au> provided a large amount of assistance dur

ing porting.
Nick Sayer <nick@specialix.com> wrote the EISA, PCI and SX

portions.

BUGS

The interrupt tuning rate is not believed to be optimal at

this time for
maximum efficiency.

Polled mode (a feature of standard Specialix drivers) is not

implemented,
but it can be approximated by turning on machdep.si_re

alpoll. The poll
frequency is set by machdep.si_pollrate (in units of 1/100th

of a second).

The driver does not yet support baud rates higher than

115,200 on SX modules.

Operation outside the traditional ISA "hole" is not yet sup

ported,
although it should work if the test is removed from the

probe routine.

Multiple host cards are supported although combinations of

hosts on different bus types have not been tested - device numbering is

known to be a
problem and may lead to unexpected results.

BSD September 16, 1995

BSD