Driver for USB-to-serial adaptors
Note:
You must be root to start this driver.
Syntax:
devc-serusb_dcd [options]
Options:
- -b baudrate
- The initial baud rate.
The supported baud rates are 75, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600 (the default),
115200, 230400, and 460800.
- -C size
- The size of the canonical buffer, in bytes (default 256).
- -d args[,args ...]
- Device-specific options; see
"Device-specific options,"
below.
- -E
- Set options to "raw" (default).
- -e
- Start in edited mode (default raw). Software flow control is enabled by default.
- -F
- Disable hardware flow control (default to hardware flow control enabled).
Hardware flow control isn't supported in edited mode.
- -f
- Enable hardware flow control (default).
Hardware flow control isn't supported in edited mode.
- -I number
- The size of the raw input buffer in bytes (default 2048).
- -O number
- ("Oh") The size of the output buffer, in bytes (default 1536).
- -o opt[,opt]...
- ("oh") A comma-separated list of additional options:
- nodaemon — don't run in the background.
- priority=prio — set the working priority of the internal pulse.
- -S|s
- Disable / enable software flow control.
The default depends on the mode: in raw mode (-E, the default), it's disabled;
in edited mode (-e), it's enabled.
The order in which you specify the -E or -e, and
-S or -s options matters:
| Options |
Mode |
Software flow control |
| -e |
Edited |
Enabled |
| -S -e |
Edited |
Enabled |
| -e -S |
Edited |
Disabled |
| -E |
Raw |
Disabled |
| -s -E |
Raw |
Disabled |
| -E -s |
Raw |
Enabled |
- -v[v]...
- Be verbose; additional v characters cause more verbosity.
Device-specific options
The device-specific options that you can specify with the -d option are:
- did=device_ID
- The device ID of the serial device.
- iface_list=number[:number]...
- Specify the USB interface number of the Communications class interface index.
This option also causes the driver to immediately create a /dev/serusbX
entry before the device is accessible to the host.
- path=name
- Connect to the specified USB stack.
The default is /dev/io-usb-dcd/io-usb.
- pindex=num
- Set the port index for subsequent port-specific options.
- priority=prio
- Set the priority of the Rx, Tx, and USB stack events.
The default priority is 21.
- ubufsz=size
- The USB transfer size.
The default is the bulk endpoints' maximum packet size, typically 512;
the buffer size is rounded up to the nearest multiple of 512.
- vid=vendor_ID
- The vendor ID of the serial device.
Description:
The devc-serusb_dcd is a driver for USB-to-serial adaptors,
which in combination with the USB device stack
(io-usb-dcd),
supports a CDC (Communications Device Class) interface presented to a connected USB host.
Note:
The
io-usb-dcd
server must be running before you start this driver.
This driver creates a /dev/serusbX entry in the pathname space, where
X is the next available integer, starting from 1.
This happens when the device becomes accessible to the host, unless you specify the iface_list
option, in which case it happens immediately.
Examples:
Start the driver with edited mode enabled, verbosity enabled, HW and SW flow control disabled,
and a USB index of 0 (which also immediately reserves the /dev/serusbX path):
devc-serusb_dcd -e -v -F -s -d iface_list=0