devc-serusb

Updated: April 19, 2023

Driver for USB-to-serial adaptors and USB CDC ACM devices

Note: You must be root or have the right abilities to start this driver.

Syntax:

devc-serusb [options]

Runs on:

QNX Neutrino

Options:

In addition to the devc-ser* options, this driver supports the following options:

-d args[,args ...]
Device-specific options. See below.
-t
Test the connection by completing the initialization but don't begin processing data and just exit afterwards. Use this option if you want to confirm that the device is connected properly, without running any data through the driver.

The device-specific options that you can specify with the -d option are:

busno=bus
The bus number of the USB controller.
debug=[rx|tx|intr|all|none]
Write raw URB data to slogger2.
devno=dev
The USB address of the device.
did=did
The device ID of the device.
drt=num
Data ready timeout (device-specific).
ifaces=idx[:idx...]
A list of USB interfaces to use. You must specify at least one interface, and use a colon (:) to separate multiple interfaces.
ign_remove
Specify to prevent the removal callback from being attached.
module=name
Set the hardware module to use for an unknown vendor ID or device ID.
name=name
The basename for the pathname entry. The default is /dev/serusb.
path=name
Connect to the specified USB stack. Default is /dev/usb/io-usb-otg.
pindex=idx
Set the port that the index options are to be applied to.
priority=prio
Set the priority of the event-processing thread. Default is 21.
query_modules
Display the currently supported hardware modules.
retry=num
The number of retries if a status of USBD_STATUS_DEV_NOANSWER is given.
rx_urbs=num
The number of URBs for BulkIn. Default is 4.
tx_urbs=num
The number of URBs for BulkOut. Default is 4.
unit=num
The unit number: 1 = /dev/serusb1, 2 = /dev/serusb2, etc. Default is the first available number, starting from 1.
vid=vid
The vendor ID of the device.
wait=num
Wait num seconds for the USB stack. Default is 60 seconds.

Description:

The devc-serusb is a driver for USB-to-serial adaptors and Communications Device Class Abstract Control Model (CDC ACM) devices. The driver automatically detects ACM devices, based on the USB Class code.

If you provide the vid, did, busno and devno arguments for device-specific options, devc-serusb doesn't attach an insertion callback to detect newly inserted devices. The driver will work only with the already-inserted device that corresponds to the arguments specified on the command line. If you don't also specify the ign_remove option, the driver is terminated when the device is removed.

The unit option has meaning only when the driver is started for a specific device by using the vid, did, busno and devno arguments. If the driver is managing device insertions, the default behavior always applies.

Note: Because devc-serusb is a USB class driver, the USB stack (io-usb-otg) must be running before you start this driver.

This driver supports a DCMD_CHR_RESET devctl() command that resets the device. Not all drivers use this command.