cy(4)

NAME

cy - Cyclades Cyclom-Y serial driver

SYNOPSIS

For one ISA card:
      device cy
      In /boot/device.hints:
      hint.cy.0.at="isa"
      hint.cy.0.irq="10"
      hint.cy.0.maddr="0xd4000"
      hint.cy.0.msize="0x2000"
For two ISA cards:
      device cy
      In /boot/device.hints:
      hint.cy.0.at="isa"
      hint.cy.0.irq="10"
      hint.cy.0.maddr="0xd4000"
      hint.cy.0.msize="0x2000"
      hint.cy.1.at="isa"
      hint.cy.1.irq="11"
      hint.cy.1.maddr="0xd6000"
      hint.cy.1.msize="0x2000"
For PCI cards:
      device cy
      options CY_PCI_FASTINTR
      No lines are required in  /boot/device.hints  for  PCI
cards.
Minor numbering:
      0bMMMMMMMMMMMMMMMMxxxxxxxxOLIMMMMM
                                callOut
                                 Lock
                                  Initial
        MMMMMMMMMMMMMMMM           MMMMMMinor

DESCRIPTION

The cy driver provides support for Cirrus Logic CD1400-based

EIA RS-232C
(CCITT V.24) communications interfaces (ports) on Cyclades

Cyclom-Y
boards. Each CD1400 provides 4 ports. Cyclom-Y boards with

various numbers of CD1400's are available. This driver supports up to

8 CD1400's
(32 ports) per board.

Input and output for each line may set independently to the

following
speeds: 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400,

4800, 9600,
19200, 38400, 57600, or 115200 bps. Other speeds of up to

150000 are
supported by the termios interface but not by the sgttyb

compatibility
interface. The CD1400 is not fast enough to handle speeds

above 115200
bps effectively. It can transmit on a single line at

slightly more than
115200 bps, but when 4 lines are active in both directions

its limit is
about 90000 bps on each line.

Serial ports controlled by the cy 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 high

er than that
of the corresponding callin port. The callin device is gen

eral 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. Pro

cesses 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 con

flict 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.

The cy driver also supports an initial-state and a lock

state control
device for each of the callin and the callout "data" de

vices. 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
stty(1) in the normal way on the initial-state devices to

program initial
termios states suitable for your setup.

The lock termios state acts as flags to disable changing the

termios
state. E.g., to lock a flag variable such as CRTSCTS, use

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.

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 hand

shaking at all
times and off for devices that do not support it at all.

CLOCAL should
be locked on for devices that do not support carrier. HUPCL

may be
locked off if you do not 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.

Kernel Configuration Options

The CY_PCI_FASTINTR option should be used to avoid subopti

mal interrupt
handling for PCI Cyclades boards. The PCI BIOS must be con

figured with
the cy interrupt not shared with any other active device for

this option
to work. This option is not the default because it is cur

rently harmful
in certain cases where it does not work.

FILES

/dev/ttyc?? for callin ports
/dev/ttyic??
/dev/ttylc?? corresponding callin initial-state and lock

state devices

/dev/cuac?? for callout ports
/dev/cuaic??
/dev/cualc?? corresponding callout initial-state and lock

state devices

/etc/rc.serial examples of setting the initial-state and

lock-state

devices

The first question mark in these device names is short for

the card number (a decimal number between 0 and 65535 inclusive). The

second question mark is short for the port number (a letter in the

range [0-9a-v]).

DIAGNOSTICS

cy%d: silo overflow. Problem in the interrupt handler.

cy%d: interrupt-level buffer overflow. Problem in the bot

tom half of the
driver.

cy%d: tty-level buffer overflow. Problem in the applica

tion. Input has
arrived faster than the given module could process it and

some has been
lost.

SEE ALSO

stty(1), termios(4), tty(4), comcontrol(8), pstat(8)

HISTORY

The cy driver is derived from the sio driver and the NetBSD

cy driver and
is currently under development.

BUGS

Serial consoles are not implemented.

BSD May 24, 2004

BSD