.\" $OpenBSD: btsco.4,v 1.3 2010/09/19 12:49:37 jmc Exp $
.\" $NetBSD: btsco.4,v 1.9 2006/10/04 19:29:25 wiz Exp $
.\"
.\" Copyright (c) 2006 Itronix Inc.
.\" All rights reserved.
.\"
.\" Written by Iain Hibbert for Itronix Inc.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" 3. The name of Itronix Inc. may not be used to endorse
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.\"
.Dd $Mdocdate: September 19 2010 $
.Dt BTSCO 4
.Os
.Sh NAME
.Nm btsco
.Nd Bluetooth SCO Audio
.Sh SYNOPSIS
.Cd "btsco*	at bthub?"
.Cd "audio*	at audiobus?"
.Sh DESCRIPTION
.Nm
provides support for Bluetooth SCO Audio devices through the
.Xr audio 4
driver.
.Nm
is configured at run time with the
btdevctl program.
.Pp
The following properties are used by
.Nm
during autoconfiguration:
.Bl -tag -width Ds
.It local-bdaddr
Local device address.
.It remote-bdaddr
Remote device address.
.It service-name
.Nm
matches the
.Sq HF
and
.Sq HSET
services.
For the
.Sq HF
service, the
.Nm
device will, on
.Xr open 2 ,
listen for incoming connections from the remote device.
Otherwise,
.Nm
will attempt to initiate a connection to the remote device.
.It rfcomm-channel
This integer value is not used directly, but will be stored and
passed via the
.Dv BTSCO_INFO
ioctl as shown below.
.El
.Pp
SCO connections require a baseband connection between the two devices before
they can be created.
.Nm
does not create this, but can provide information to facilitate
an application setting up a control channel prior to use, via the
.Dv BTSCO_INFO
.Xr ioctl 2
call on the mixer device, which returns a
.Ar btsco_info
structure as follows:
.Bd -literal -offset 3n
#include <dev/bluetooth/btsco.h>

struct btsco_info {
	bdaddr_t	laddr;		/* controller bdaddr */
	bdaddr_t	raddr;		/* headset bdaddr */
	uint8_t		channel;	/* RFCOMM channel */
	int		vgs;		/* mixer index speaker */
	int		vgm;		/* mixer index mic */
};

#define BTSCO_INFO	_IOR('b', 16, struct btsco_info)
.Ed
.Pp
.Nm
can be configured to act in Connect or Listen mode.
In Connect mode,
it will initiate a connection to the remote device on an
.Xr open 2
call, whereas in Listen mode
.Xr open 2
will block until the remote device initiates the connection.
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr audio 4 ,
.Xr bluetooth 4
.Sh HISTORY
The
.Nm
driver
was written for
.Nx 4.0
by
.An Iain Hibbert
under the sponsorship of Itronix, Inc.
.Sh BUGS
.Nm
takes no notice of the HCI Voice Setting in the Bluetooth controller,
and must be 0x0060 (the default)
as alternate values are currently unsupported.