xref: /dflybsd-src/share/man/man4/ubt.4 (revision a1fe33c86e44a3bb272c65e3c8c8e36ddba6ec90)

.\" $NetBSD: ubt.4,v 1.5 2006/09/02 23:54:23 wiz Exp $
.\" $DragonFly: src/share/man/man4/ubt.4,v 1.1 2008/02/01 12:24:40 hasso Exp $
.\"
.\" Copyright (c) 2006 Itronix Inc.
.\" All rights reserved.
.\"
.\" Written by Iain Hibbert for Itronix Inc.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of Itronix Inc. may not be used to endorse
.\"    or promote products derived from this software without specific
.\"    prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
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.\"
.Dd August 27, 2006
.Dt UBT 4
.Os
.Sh NAME
.Nm ubt
.Nd USB Bluetooth driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device ubt"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
ubt_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for USB Bluetooth dongles
to the Bluetooth protocol stack.
.\".Pp
.\"USB Bluetooth dongles provide two interfaces, both of which the
.\".Nm
.\"driver claims.
.\"The second interface is used for Isochronous data and will have
.\"several alternate configurations regarding bandwidth consumption,
.\"which can be set using the hw.ubtN.config
.\".Xr sysctl 8
.\"variable.
.\"The number of alternate configurations is indicated by the value
.\"in the hw.ubtN.alt_config variable, and the isoc frame size for the current
.\"configuration is shown in the hw.ubtN.sco_rxsize and hw.ubtN.sco_txsize
.\"variables.
.\".Pp
.\"By default, configuration 0 is selected, which means that no bandwidth
.\"is used on the Isochronous interface and no SCO data can be sent.
.\"Consult the Bluetooth USB specification at https://www.bluetooth.org/
.\"for complete instructions on setting bandwidth consumption.
.\"The following extract may be
.\"useful as a general guidance though details may differ between manufacturers.
.\".Pp
.\".Bl -tag -compact -width XXX
.\".It 0
.\"No active voice channels
.\".It 1
.\"One voice channel with 8-bit encoding
.\".It 2
.\"Two voice channels with 8-bit encoding, or one voice channel with
.\"16-bit encoding.
.\".It 3
.\"Three voice channels with 8-bit encoding
.\".It 4
.\"Two voice channels with 16-bit encoding
.\".It 5
.\"Three voice channels with 16-bit encoding
.El
.Sh SEE ALSO
.Xr bluetooth 4
.\".Xr uhub 4 ,
.\".Xr sysctl 8
.Sh HISTORY
This
.Nm
device driver was originally a character device written by
.An David Sainty
and
.An Lennart Augustsson .
It was rewritten to support socket based Bluetooth access for
.Nx 4.0
by
.An Iain Hibbert .
The
.Nm
driver was imported into
.Dx 1.11 .
.\".Sh CAVEATS
.\"Isochronous data is seemingly not well supported over USB in the current
.\"system and to get SCO working, you may have to calculate the SCO packet
.\"size that the stack will use.
.\"This is the sco_mtu value reported by the
.\".Xr btconfig 8
.\"command, and when combined with the SCO header (3 bytes) should
.\"fit exactly into an integer number of Isochronous data frames where
.\"the frame size is indicated by the
.\".Sq hw.ubtN.sco_txsize
.\"sysctl variable.
.\".Pp
.\"For example: I want one voice channel (which is all that is supported,
.\"for now) so am using configuration #2, with a frame length of 17
.\"bytes.
.\"This gives possible values of:
.\".Pp
.\".Dl "(17 * 1) - 3 = 14"
.\".Dl "(17 * 2) - 3 = 31"
.\".Dl "(17 * 3) - 3 = 48"
.\".Dl "(17 * 4) - 3 = 65"
.\".Dl "(17 * 5) - 3 = 82"
.\".Dl "etc."
.\".Pp
.\".Xr btconfig 8
.\"shows the maximum SCO payload as 64 bytes, so I am using the next smaller
.\"size of 48, to minimize the overhead of the 3 header bytes.
.\".Pp
.\"The SCO packet size can be changed using the
.\".Sq scomtu
.\"option to
.\".Xr btconfig 8 .
.\".Pp
.\"The failure mode is that the USB Bluetooth dongle locks up though
.\"generally removal/reinsertion will clear the problem.
.\".Sh BUGS
.\"The Isochronous configuration can only be changed when the device is not
.\"marked up.