.\" Copyright (c) 2004 Bruce M. Simpson <bms@spc.org>

.\" Copyright (c) 2004 Darron Broad <darron@kewl.org>

.Ft u_int

.Fn ieee80211_mhz2ieee "u_int freq" "u_int flags"

.Ft u_int

.Fn ieee80211_chan2ieee "struct ieee80211com *ic" "struct ieee80211_channel *c"

.Ft u_int

.Fn ieee80211_ieee2mhz "u_int chan" "u_int flags"

.Ft int

.Fn ieee80211_media_change "struct ifnet *ifp"

.Ft void

.Fn ieee80211_media_status "struct ifnet *ifp" "struct ifmediareq *imr"

.Ft int

.Fn ieee80211_setmode "struct ieee80211com *ic" "enum ieee80211_phymode mode"

.Ft enum ieee80211_phymode

.Fo ieee80211_chan2mode

.Fa "const struct ieee80211_channel *chan"

.Fc

.Ft int

.Fo ieee80211_rate2media

.Fa "struct ieee80211com *ic" "int rate" "enum ieee80211_phymode mode"

.Fc

.Ft int

.Fn ieee80211_media2rate "int mword"

.Pp

Most of these functions require that attachment to the stack is performed

before calling.

.Pp

.\"

The

.Fn ieee80211_ifattach

function attaches the wireless network interface

.Fa ic

to the 802.11 network stack layer.

This function must be called before using any of the

.Nm

functions which need to store driver state across invocations.

.Pp

.\"

The

.Fn ieee80211_ifdetach

function frees any

.Nm

structures associated with the driver, and performs Ethernet and BPF

detachment on behalf of the caller.

.Pp

.\"

The

.Fn ieee80211_mhz2ieee

utility function converts the frequency

.Fa freq

(specified in MHz) to an IEEE 802.11 channel number.

The

.Fa flags

argument is a hint which specifies whether the frequency is in

the 2GHz ISM band

.Pq Vt IEEE80211_CHAN_2GHZ

or the 5GHz band

.Pq Vt IEEE80211_CHAN_5GHZ ;

appropriate clipping of the result is then performed.

.Pp

.\"

The

.Fn ieee80211_chan2ieee

function converts the channel specified in

.Fa *c

to an IEEE channel number for the driver

.Fa ic .

If the conversion would be invalid, an error message is printed to the

system console.

This function REQUIRES that the driver is hooked up to the

.Nm

subsystem.

.Pp

.\"

The

.Fn ieee80211_ieee2mhz

utility function converts the IEEE channel number

.Ft chan

to a frequency (in MHz).

The

.Fa flags

argument is a hint which specifies whether the frequency is in

the 2GHz ISM band

.Pq Vt IEEE80211_CHAN_2GHZ

or the 5GHz band

.Pq Vt IEEE80211_CHAN_5GHZ ;

appropriate clipping of the result is then performed.

.Pp

.\"

The

.Fn ieee80211_media_status

and

.Fn ieee80211_media_change

functions are device-independent handlers for

.Vt ifmedia

commands and are not intended to be called directly.

.Pp

.\"

The

.Fn ieee80211_setmode

function is called from within the 802.11 stack to change the mode

of the driver's PHY; it is not intended to be called directly.

.Pp

.\"

The

.Fn ieee80211_chan2mode

function returns the PHY mode required for use with the channel

.Fa chan .

This is typically used when selecting a rate set, to be advertised in

beacons, for example.

.Pp

.\"

The

.Fn ieee80211_rate2media

function converts the bit rate

.Fa rate

(measured in units of 0.5Mbps) to an

.Vt ifmedia

sub-type, for the device

.Fa ic

running in PHY mode

.Fa mode .

The

.Fn ieee80211_media2rate

performs the reverse of this conversion, returning the bit rate (in 0.5Mbps

units) corresponding to an

.Vt ifmedia

sub-type.

.

.Sh HISTORY

The

.Nm

series of functions first appeared in

.Nx 1.5 ,

and were later ported to

.Fx 4.6 .

This man page was updated with the information from

.Nx

.Nm

man page. 

.Sh AUTHORS

.An -nosplit

The original

.Nx

.Nm

man page was written by

.An Bruce M. Simpson Aq Mt bms@FreeBSD.org

and

.An Darron Broad Aq Mt darron@kewl.org .