path: root/Documentation/usb/usb-serial.txt

INTRODUCTION

  The USB serial driver currently supports a number of different USB to
  serial converter products, as well as some devices that use a serial
  interface from userspace to talk to the device.

  See the individual product section below for specific information about
  the different devices.


CONFIGURATION

  Currently the driver can handle up to 256 different serial interfaces at
  one time. 

  If you are not using devfs:
    The major number that the driver uses is 188 so to use the driver,
    create the following nodes:
	mknod /dev/ttyUSB0 c 188 0
	mknod /dev/ttyUSB1 c 188 1
	mknod /dev/ttyUSB2 c 188 2
	mknod /dev/ttyUSB3 c 188 3
		.
		.
		.
	mknod /dev/ttyUSB254 c 188 254
	mknod /dev/ttyUSB255 c 188 255

  If you are using devfs:
    The devices supported by this driver will show up as
    /dev/usb/tts/{0,1,...}

  When the device is connected and recognized by the driver, the driver
  will print to the system log, which node(s) the device has been bound
  to.
  

SPECIFIC DEVICES SUPPORTED


ConnectTech WhiteHEAT 4 port converter

  ConnectTech has been very forthcoming with information about their
  device, including providing a unit to test with. This driver will end up
  being fully supported.

Current status:
  The device's firmware is downloaded on connection, the new firmware 
  runs properly and all four ports are successfully recognized and connected.
  Data can be sent and received through the device on all ports.
  Hardware flow control needs to be implemented.


HandSpring Visor USB docking station

Current status:
  Only when the Visor tries to connect to the host, does the docking
  station show up as a valid USB device. When this happens, the device is
  properly enumerated, assigned a port, and then communication _should_ be
  possible. The driver cleans up properly when the device is removed, or
  the connection is canceled on the Visor.

  NOTE:
    This means that in order to talk to the Visor, the sync button must be
    pressed BEFORE trying to get any program to communicate to the Visor.
    This goes against the current documentation for pilot-xfer and other
    packages, but is the only way that it will work due to the hardware
    in the Visor.
  
  When the device is connected, try talking to it on the second port
  (this is usually /dev/ttyUSB1 if you do not have any other usb-serial
  devices in the system.) The system log should tell you which port is
  the port to use for the HotSync transfer. The "Generic" port can be used
  for other device communication, such as a PPP link.

  If after pressing the sync button, nothing shows up in the system log,
  try resetting the Visor, first a hot reset, and then a cold reset if
  necessary.  Some Visors need this before they can talk to the USB port
  properly.
  
  There is a webpage and mailing lists for this portion of the driver at: 
  http://usbvisor.sourceforge.net/


Keyspan PDA Serial Adapter

  Single port DB-9 serial adapter, pushed as a PDA adapter for iMacs (mostly
  sold in Macintosh catalogs, comes in a translucent white/green dongle).
  Fairly simple device. Firmware is homebrew.

Current status:
 Things that work:
   basic input/output (tested with 'cu')
   blocking write when serial line can't keep up
   changing baud rates (up to 115200)
   getting/setting modem control pins (TIOCM{GET,SET,BIS,BIC})
   sending break (although duration looks suspect)
 Things that don't:
   device strings (as logged by kernel) have trailing binary garbage
   device ID isn't right, might collide with other Keyspan products
   changing baud rates ought to flush tx/rx to avoid mangled half characters
 Big Things on the todo list:
   parity, 7 vs 8 bits per char, 1 or 2 stop bits
   HW flow control
   not all of the standard USB descriptors are handled: Get_Status, Set_Feature
   O_NONBLOCK, select()


Keyspan USA-series Serial Adapters

  Single, Dual and Quad port adapters - driver uses Keyspan supplied 
  firmware and is being developed with their support.
  
Current status:
  The USA-18X, USA-28X, USA-19, USA-19W and USA-49W are supported and
  have been pretty throughly tested at various baud rates with 8-N-1
  character settings.  Other character lengths and parity setups are
  presently untested.

  The USA-28 isn't yet supported though doing so should be pretty
  straightforward.  Contact the maintainer if you require this
  functionality.
  
  More information is available at:
        http://www.linuxcare.com.au/hugh/keyspan.html
   

FTDI Single Port Serial Driver

  This is a single port DB-25 serial adapter. More information about this
  device and the Linux driver can be found at:
	http://reality.sgi.com/bryder_wellington/ftdi_sio/


ZyXEL omni.net lcd plus ISDN TA

  This is an ISDN TA. Please report both successes and troubles to the
  author at omninet@kroah.com


Digi AccelePort Driver

  This driver supports the Digi AccelePort USB 2 and 4 devices, 2 port
  (plus a parallel port) and 4 port USB serial converters.  The driver
  does NOT yet support the Digi AccelePort USB 8.

  This driver works under SMP with the usb-uhci driver.  It does not
  work under SMP with the uhci driver.

  The driver is generally working, though we still have a few more ioctls
  to implement and final testing and debugging to do.  The paralled port
  on the USB 2 is supported as a serial to parallel converter; in other
  words, it appears as another USB serial port on Linux, even though
  physically it is really a parallel port.  The Digi Acceleport USB 8
  is not yet supported.

  Please contact Peter Berger (pberger@brimson.com) or Al Borchers
  (alborchers@steinerpoint.com) for questions or problems with this
  driver.


Belkin USB Serial Adapter F5U103

  Single port DB-9/PS-2 serial adapter from Belkin with firmware by eTEK Labs.
  The Peracom single port serial adapter also works with this driver.

Current status:
  The following have been tested and work:
    Baud rate    300-230400               
    Data bits    5-8
    Stop bits    1-2
    Parity       N,E,O,M,S
    Handshake    None, Software (XON/XOFF), Hardware (CTSRTS,CTSDTR)*
    Break        Set and clear
    Line contrl  Input/Output query and control **

    *  Hardware input flow control is only enabled for firmware
       levels above 2.06.  Read source code comments describing Belkin
       firmware errata.  Hardware output flow control is working for all
       firmware versions.
    ** Queries of inputs (CTS,DSR,CD,RI) show the last
       reported state.  Queries of outputs (DTR,RTS) show the last
       requested state and may not reflect current state as set by
       automatic hardware flow control.

TO DO List:
  -- Add true modem contol line query capability.  Currently tracks the
     states reported by the interrupt and the states requested.
  -- Add error reporting back to application for UART error conditions.
  -- Add support for flush ioctls.
  -- Add everything else that is missing :)


Empeg empeg-car Mark I/II Driver (empeg.c)

  This is an experimental driver to provide connectivity support for the
  client synchronization tools for an Empeg empeg-car mp3 player.

  Tips:

    * Don't forget to create the device nodes for ttyUSB{0,1,2,...}
    * modprobe empeg (modprobe is your friend)
    * emptool --usb /dev/ttyUSB0 (or whatever you named your device node)

  The driver is still pretty new, so some testing 'in the wild' would be
  helpful. :)


MCT USB Single Port Serial Adapter U232

 This driver is for the MCT USB-RS232 Converter (25 pin, Model No.
 U232-P25) from Magic Control Technology Corp. (there is also a 9 pin
 Model No. U232-P9). More information about this device can be found
 at the manufacture's web-site: http://www.mct.com.tw.

 The driver is generally working, though it still needs some more
 testing. It is derived from the Belkin USB Serial Adapter F5U103
 driver and its TODO list is valid for this driver as well.

 This driver has also been found to work for other products, which have 
 the same Vendor ID but different Product IDs. Sitecom's U232-P25 
 serial converter uses Product ID 0x230 and Vendor ID 0x711 and works with 
 this driver. Also, D-Link's DU-H3SP USB BAY also works with this driver.


Inside Out Networks Edgeport Driver

  This driver supports all devices made by Inside Out Networks, specifically
  the following models:
       Edgeport/4
       Rapidport/4
       Edgeport/4t
       Edgeport/2
       Edgeport/4i
       Edgeport/2i
       Edgeport/421
       Edgeport/21
       Edgeport/8
       Edgeport/8 Dual
       Edgeport/2D8
       Edgeport/4D8
       Edgeport/8i
       Edgeport/2 DIN
       Edgeport/4 DIN
       Edgeport/16 Dual


Generic Serial driver

  If your device is not one of the above listed devices, compatible with
  the above models, you can try out the "generic" interface. This
  interface does not provide any type of control messages sent to the
  device, and does not support any kind of device flow control. All that
  is required of your device is that it has at least one bulk in endpoint,
  or one bulk out endpoint. 
  
  To enable the generic driver to recognize your device, build the driver
  as a module and load it by the following invocation:
	insmod usbserial vendor=0x#### product=0x####
  where the #### is replaced with the hex representation of your device's
  vendor id and product id.

  This driver has been successfully used to connect to the NetChip USB
  development board, providing a way to develop USB firmware without
  having to write a custom driver.


CONTACT:

  If anyone has any problems using this driver, with any of the above
  specified products, please contact me, or join the Linux-USB mailing
  list (information on joining the mailing list, as well as a link to its
  searchable archive is at http://www.linux-usb.org/ )


Greg Kroah-Hartman
greg@kroah.com