USBFTDI(4D) Devices USBFTDI(4D)

NAME

usbftdi - FTDI USB to serial converter driver

SYNOPSIS

#include <fcntl.h>
#include <sys/termio.h>
usbftdi@unit

DESCRIPTION

The usbftdi driver is a loadable STREAMS and USBA (Solaris USB
Architecture) compliant client driver that provides basic
asynchronous communication support for FTDI USB-to-serial converters.
Serial device streams are built with appropriate modules that are
pushed atop the usbftdi driver by the autopush(8) facility.

Application Programming Interface

The usbftdi module supports the termio(4I) device control functions
specified by flags in the c_cflag word of the termios structure, and
by the IGNBRK, IGNPAR, PARMRK, and INPCK flags in the c_iflag word of
the termios structure. All other termio(4I) functions must be
performed by STREAMS modules pushed atop the driver. When a device is
opened, the , ldterm(4M) and ttcompat(4M) STREAMS modules are
automatically pushed on top of the stream, providing the standard
termio(4I) interface.


Use device logical names /dev/term/[0-9]* to access the serial ports
for a dial-in line that is used with a modem.


Use device logical names /dev/cua/[0-9]* to access the serial ports
for other applications. These names are also used to provide a
logical access point for a dial-out line.


Device hot-removal is functionally equivalent to a modem disconnect
event, as defined in termio(4I).


Input and output line speeds can be set to the following baud rates:
300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200,
230400, 460800, 921600, 2000000, or 3000000. Input and output line
speeds can not be set independently. For example, when the output
speed is set, the input speed is automatically set to the same speed.

Soft Carrier Capabilities

Many devices that use this USB serial interface component are not, in
fact dial-in lines connected to carefully configured RS-232 modems.
They are often intelligent peripherals whose manufacturers want to
present a serial port interface to application software. Some
applications use only three wire connections, or are otherwise
somewhat casual about the state of the Carrier Detect (electrical)
signal, and the other modem control lines.


The configuration file delivered with this driver, usbftdi.conf,
acknowledges this by setting the driver property ignore-cd to 1. This
enables soft carrier mode where the kernel does not block opens
waiting for DCD to be asserted.


This behavior also matches the default ignore carrier detect behavior
of the onboard serial ports of machines that have them. See eeprom(8)
for further details.


The hardware carrier behavior (the driver's internal default) can be
selected by either unsetting (commenting out) the ignore-cd property,
or by setting the value of the property to zero.


More sophisticated selection of which devices ignore or obey the DCD
signal can be effected using port-%d-ignore-cd properties.

Dial-In and Dial-Out Support
A related feature is available for traditional usage that enables a
single tty line to be connected to a modem and used for incoming and
outgoing calls. By accessing through device logical name
/dev/cua/[0-9]*, you can open a port without the carrier detect
signal being asserted, either through hardware or an equivalent
software mechanism. These devices are commonly known as dial-out
lines.


A dial-in line can be opened only if the corresponding dial-out line
is closed. A blocking /dev/term open waits until the /dev/cua line
is closed, which drops Data Terminal Ready, after which Carrier
Detect usually drops as well. When the carrier is detected again
with the /dev/cua device remaining closed, this indicates an incoming
call and the blocking open seizes exclusive use of the line.


A non-blocking /dev/term open returns an error if the /dev/cua device
is open.


If the /dev/term line is opened successfully (usually only when
carrier is recognized on the modem, though see Soft Carrier
Capabilities section of this manual page), the corresponding /dev/cua
line can not be opened. This allows a modem and port to be used for
dial-in (enabling the line for login in /etc/inittab) or dial-out
(using tip(1) or uucp(1C)) when no-one is logged in on the line.

ERRORS

An open() fails under the following conditions:

ENXIO
The unit being opened does not exist.


EBUSY
The /dev/cua (dial-out) device is being opened while the
/dev/term (dial-in device) is open, or the dial-in device is
being opened with a no-delay open while the dial-out device
is open.


EBUSY
The unit has been marked as exclusive-use by another process
with a TIOCEXCL ioctl() call.


EIO
USB device I/O error.

FILES

/usr/kernel/drv/usbftdi

32-bit x86 ELF kernel module


/usr/kernel/drv/usbftdi.conf

Kernel module configuration file


/usr/kernel/drv/amd64/usbftdi

64-bit x86 ELF kernel module


/usr/kernel/drv/sparcv9/usbftdi

64-bit SPARC ELF kernel module


/dev/cua/[0-9]*

Dial-out tty lines


/dev/term/[0-9]*

Dial-in tty lines

ATTRIBUTES

See attributes(7) for a description of the following attribute:


+----------------+-------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+----------------+-------------------------------+
|Architecture | SPARC, x86, PCI-based systems |
+----------------+-------------------------------+

SEE ALSO

strconf(1), tip(1), uucp(1C), autopush(8), eeprom(8), ioctl(2),
open(2), termios(3C), usba(4D), termio(4I), ldterm(4M), ttcompat(4M),
eeprom(8), attributes(7),

DIAGNOSTICS

In addition to being logged, the following messages might appear on
the system console. All messages are formatted in the following
manner:

Warning: device_path usbftdiinstance num): Error Message ...


Device was disconnected while open. Data may have been lost.

The device has been hot-removed or powered off while it was open
and a possible data transfer was in progress. The job might be
aborted.


Device is not identical to the previous one on this port. Please
disconnect and reconnect.

The device was hot-removed while open. A new device was hot-
inserted which is not identical to the original device. Please
disconnect the device and reconnect the original device to the
same port.


Device has been reconnected, but data may have been lost.

The device that was hot-removed from its USB port has been re-
inserted again to the same port. It is available for access but
data from a previous transfer might be lost.


Cannot access device. Please reconnect.

This device has been disconnected because a device other than the
original one has been inserted. The driver informs you of this
fact by displaying the name of the original device.


The following messages might be logged into the system log. They are
formatted in the following manner:

device_path usbftdiiinstance number): message ...


Input overrun.
Data was lost.


March 10, 2023 USBFTDI(4D)