.\"	$OpenBSD: radio.9,v 1.11 2016/08/31 16:54:33 jmc Exp $
.\"	$RuOBSD: radio.9,v 1.3 2001/10/26 05:38:44 form Exp $
.\"
.\" Copyright (c) Maxim Tsyplakov <tm@oganer.net>
.\" All rights reserved.
.\"
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
.\" ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: August 31 2016 $
.Dt RADIO 9
.Os
.Sh NAME
.Nm radio
.Nd interface between low and high level radio drivers
.Sh DESCRIPTION
The radio device driver is divided into a high level,
hardware independent layer, and a low level hardware
dependent layer.
The interface between these is the
.Va radio_hw_if
structure.
.Bd -literal
struct radio_hw_if {
	int	(*open)(void *, int, int, struct proc *);
	int	(*close)(void *, int, int, struct proc *);
	int     (*get_info)(void *, struct radio_info *);
	int     (*set_info)(void *, struct radio_info *);
	int     (*search)(void *, int);
};
.Ed
.Pp
The high level radio driver attaches to the low level driver
when the latter calls
.Va radio_attach_mi .
This call should be
.Bd -literal
.Ft void
.Fn radio_attach_mi "struct radio_hw_if *rhwp" "void *hdlp" \
                    "struct device * dev"
.Ed
.Pp
The
.Va radio_hw_if
struct is as shown above.
The
.Va hdlp
argument is a handle to some low level data structure.
It is sent as the first argument to all the functions in
.Va radio_hw_if
when the high level driver calls them.
.Va dev
is the device struct for the hardware device.
.Pp
The fields of
.Va radio_hw_if
are described in some more detail below.
.Bd -literal
.Ft int
.Fn open "void *" "int flags" "int fmt" "struct proc *p"
  Optional.
  Is called when the radio device is opened.
  Returns 0 on success, otherwise an error code.

.Ft int
.Fn close "void *" "int flags" "int fmt" "struct proc *p"
  Optional.
  Is called when the radio device is closed.
  Returns 0 on success, otherwise an error code.

.Ft int
.Fn get_info "void *" "struct radio_info *"
  Fill the radio_info struct.
  Returns 0 on success, otherwise an error code.

.Ft int
.Fn set_info "void *" "struct radio_info *"
  Set values from the radio_info struct.
  Returns 0 on success, otherwise an error code.

.Ft int
.Fn search "void *" "int"
  Returns 0 on success, otherwise an error code.
.Ed
.Sh SEE ALSO
.Xr radio 4
.Sh HISTORY
The
.Nm
device driver appeared in
.Ox 3.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Vladimir Popov Aq Mt jumbo@narod.ru
and
.An Maxim Tsyplakov Aq Mt tm@oganer.net .
The man page was written by
.An Maxim Tsyplakov Aq Mt tm@oganer.net .