CX(4)

NAME
cx, if_cx - asynchronous/synchronous Cronyx-Sigma adapter driver

CONFIGURATION
device cx0 at isa? port 0x240 irq 15 drq 7 device cx1 at isa? port 0x260 irq 12 drq 6 pseudo-device sppp

The base i/o port address should be set by jumpers on the board. The DMA i/o channel and interrupt request numbers are configured by software at adapter initialization. Legal values are:

Port
    0x240, 0x260, 0x280, 0x300, 0x320, 0x380
IRQ 3, 5, 7, 10, 11, 12, 15
DMA 5, 6, 7

DESCRIPTION
The Cronyx-Sigma driver supports the adapters of models 100, 400, 500, 401, 404, 410, 440, 703, 801, 810, 840. Different models have different set of channels:

Model
    Channels
Cronyx-Sigma-100
    0
Cronyx-Sigma-400
    4, 5, 6, 7
Cronyx-Sigma-500
    0, 4, 5, 6, 7
Cronyx-Sigma-401
    0, 1, 2, 3
Cronyx-Sigma-404
    0, 1, 2, 3
Cronyx-Sigma-410
    0, 1, 2, 3
Cronyx-Sigma-440
    0, 1, 2, 3
Cronyx-Sigma-703
    0, 1, 2, 4, 5, 6, 7
Cronyx-Sigma-801
    0, 1, 2, 3, 4, 5, 6, 7
Cronyx-Sigma-810
    0, 1, 2, 3, 4, 5, 6, 7
Cronyx-Sigma-840
    0, 1, 2, 3, 4, 5, 6, 7

A pair of two adapters can be united together by the special short inter-board cable. Two united adapters use the same IRQ and DMA channels and from the point of driver works as the single 16-channel multiplexer. One of the united boards is ``master'' and the other is ``slave''.

The channels of the slave united board are numbered by the driver beginning with 8, for example, the united adapter of the model 100/500 has channels 0, 8, 12, 13, 14, 15.

The channels which have the RS-232 interface can be used both in synchronous and asynchronous modes (software selectable by cxconfig utility) and hence are called ``universal'' channels.

The special device files, /dev/*, for the adapter Cronyx-Sigma are created by th MAKEDEV(8) An example:

    cd /dev
    sh MAKEDEV cronyx ttyx0 ttyx1 ttyy0

Asynchronous driver

The asynchronous channel device files have the names: /dev/ttyx# - for adapter cx0, /dev/ttyy# - for adapter cx1, /dev/ttyz# - for cx2. Here # is the channel number in hexadecimal form, 0-9-a-f.

The driver fulfills the following standard ioctl requests (see ioctl):

TIOCSBRK
    Start sending BREAK.
TIOCCBRK
    Stop sending BREAK.
TIOCSDTR
    Set DTR signal (DTR := 1). The DTR signal is always set on the first open(2) and could be changed by TIOCCDTR, TIOCSDTR, TIOCMSET, TIOCMBIS, TIOCMBIC ioctl calls.
TIOCCDTR
    Clear DTR signal (DTR := 0).
TIOCMSET
    Set the given values of DTR and RTS signals (<DTR:RTS> := data). The signals DTR and RTS are controlled by TIOCM_DTR and bits of the data argument of the ioctl system call.
TIOCMBIS
    Set DTR and RTS signals (<DTR:RTS> |= data). The signals DTR and RTS are controlled by TIOCM_DTR and TIOCM_RTS bits of the data argument of the ioctl system call.
TIOCMBIC
    Clear DTR and RTS signals (<DTR:RTS> &= ~data). The signals DTR and RTS are controlled by TIOCM_DTR and TIOCM_RTS bits of the data argument of the ioctl system call.
TIOCMGET
    Determine the state of the modem signals of the line. After the call the data argument contains the following bits:

    TIOCM_LE
        always set (Line Enabled)
    TIOCM_DSR
        Data Set Ready signal received
    TIOCM_CTS
        Clear To Send signal received
    TIOCM_CD
        Data Carrier Detect signal received
    TIOCM_DTR
        Data Terminal Ready signal transmitted
    TIOCM_RTS
        Request To Send signal transmitted

Synchronous driver

The synchronous channels and universal channels, turned to the synchronous mode by the cxconfig(8) utility, are accessible as network interfaces named ``cx#'' where # is the channel number, 0..47. All standard network interface parameters could be set by ifconfig(8) utility. The cxconfig(8) command is used to change some extended channel options, and also for setting the high-level software protocol (e.g. PpP or Cisco HDLC).

The universal channels could be used both in asynchronous and synchronous modes. By default the asynchronous mode is set. The mode could be changed by cxconfig(8) utility. The mode is blocked while the channel is busy (an asynchronous channel in open state or the network interface is up).

The Cronyx-Sigma driver uses the built-in implementation of the synchronous Point-to-Point protocol (sppp). It includes the support for such protocols as PpP/HDLC and Cisco/HDLC, and also the automatic connection loss test (via keepalive packets). The sppp protocol set is implemented as an independent module and could be used by other drivers of synchronous serial channels. The version of the driver for BSD/386 (BSDI) operating system also supports the usage of the general set of synchronous protocols, implemented inside the OS. The external protocol set could be selected by ``cxconfig ext'' command (see cxconfig(8)).

Channel Options Management

The cxconfig(8) utility is used for setting the channels options. The channel options are generally set at the start of the operating system (for example, from the file /etc/rc). Note, that not all options have a sense for every particular case, and an attempt to set some of them can hang up the channel or the whole adapter.

The actual channel options control functions are implemented via the ioctl-s on the special device file /dev/cronyx. There are the following ioctl-s available:

CXIOCGETMODE
    Get the channel option values.
CXIOCSETMODE
    Set the channel option values.

The data argument of the ioctl call has an address of the options structure:

    typedef struct {
        unsigned char board;   /* adapter number, 0..2 */
        unsigned char channel; /* channel number, 0..15 */
        unsigned char type;    /* channel type (read only) */
        unsigned char iftype;  /* chan0 interface */
        unsigned long rxbaud;  /* receiver speed */
        unsigned long txbaud;  /* transmitter speed */
        cx_chan_mode_t mode;   /* channel mode */
        cx_chan_opt_t opt;     /* common channel options */
        cx_opt_async_t aopt;   /* async mode options */
        cx_opt_hdlc_t hopt;    /* hdlc mode options */
        cx_opt_bisync_t bopt;  /* bisync mode options */
        cx_opt_x21_t xopt;     /* x.21 mode options */
        cx_soft_opt_t sopt;    /* software options and state flags */
    } cx_options_t;            /* user settable options */

board
    The adapter number, 0..2.

channel
    The channel number, 0..15.

type
    The type of the channel (read-only argument).

iftype
    The interface type of the zero (and also the eight) channel: 0 - RS-232, 1 - RS-449/V.35.

rxbaud
    The receiver data baud rate.

txbaud
    The transmitter data baud rate.

mode
    The channel mode: asynchronous/HDLC/Bisync/X.21.

opt The general channel options.

aopt
    The asynchronous mode options.

hopt
    The HDLC mode options.

bopt
    The Bisync mode options.

xopt
    The X.21 mode options.

sopt
    The software protocol options.

FILES
/dev/cx??
    Asynchronous channels.
/dev/cronyx
The special device file for the channel options management.

The sources for the driver reside in:

/sys/i386/isa/cronyx.c
/sys/i386/isa/cx.c
/sys/i386/isa/if_cx.c
/sys/i386/isa/cronyx.h
/sys/i386/isa/cxreg.h
/sys/net/if_spppsubr.c
/sys/net/if_sppp.h

SEE ALSO
cxconfig(8), ifconfig(8)