2 * Copyright (c) 2010 Broadcom Corporation
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
11 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 #include <brcmu_wifi.h>
19 * Verify the chanspec is using a legal set of parameters, i.e. that the
20 * chanspec specified a band, bw, ctl_sb and channel and that the
21 * combination could be legal given any set of circumstances.
22 * RETURNS: true is the chanspec is malformed, false if it looks good.
24 bool brcmu_chspec_malformed(u16 chanspec
)
26 /* must be 2G or 5G band */
27 if (!CHSPEC_IS5G(chanspec
) && !CHSPEC_IS2G(chanspec
))
29 /* must be 20 or 40 bandwidth */
30 if (!CHSPEC_IS40(chanspec
) && !CHSPEC_IS20(chanspec
))
33 /* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
34 if (CHSPEC_IS20(chanspec
)) {
35 if (!CHSPEC_SB_NONE(chanspec
))
37 } else if (!CHSPEC_SB_UPPER(chanspec
) && !CHSPEC_SB_LOWER(chanspec
)) {
43 EXPORT_SYMBOL(brcmu_chspec_malformed
);
46 * This function returns the channel number that control traffic is being sent
47 * on, for legacy channels this is just the channel number, for 40MHZ channels
48 * it is the upper or lower 20MHZ sideband depending on the chanspec selected.
50 u8
brcmu_chspec_ctlchan(u16 chspec
)
54 /* Is there a sideband ? */
55 if (CHSPEC_CTL_SB(chspec
) == WL_CHANSPEC_CTL_SB_NONE
) {
56 return CHSPEC_CHANNEL(chspec
);
59 * we only support 40MHZ with sidebands. chanspec channel holds
60 * the centre frequency, use that and the side band information
61 * to reconstruct the control channel number
63 if (CHSPEC_CTL_SB(chspec
) == WL_CHANSPEC_CTL_SB_UPPER
)
65 * control chan is the upper 20 MHZ SB of the
68 ctl_chan
= UPPER_20_SB(CHSPEC_CHANNEL(chspec
));
71 * control chan is the lower 20 MHZ SB of the
74 ctl_chan
= LOWER_20_SB(CHSPEC_CHANNEL(chspec
));
79 EXPORT_SYMBOL(brcmu_chspec_ctlchan
);
82 * Return the channel number for a given frequency and base frequency.
83 * The returned channel number is relative to the given base frequency.
84 * If the given base frequency is zero, a base frequency of 5 GHz is assumed for
85 * frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
87 * Frequency is specified in MHz.
88 * The base frequency is specified as (start_factor * 500 kHz).
89 * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
90 * 2.4 GHz and 5 GHz bands.
92 * The returned channel will be in the range [1, 14] in the 2.4 GHz band
93 * and [0, 200] otherwise.
94 * -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
95 * frequency is not a 2.4 GHz channel, or if the frequency is not and even
96 * multiple of 5 MHz from the base frequency to the base plus 1 GHz.
98 * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
100 int brcmu_mhz2channel(uint freq
, uint start_factor
)
106 /* take the default channel start frequency */
107 if (start_factor
== 0) {
108 if (freq
>= 2400 && freq
<= 2500)
109 start_factor
= WF_CHAN_FACTOR_2_4_G
;
110 else if (freq
>= 5000 && freq
<= 6000)
111 start_factor
= WF_CHAN_FACTOR_5_G
;
114 if (freq
== 2484 && start_factor
== WF_CHAN_FACTOR_2_4_G
)
117 base
= start_factor
/ 2;
119 /* check that the frequency is in 1GHz range of the base */
120 if ((freq
< base
) || (freq
> base
+ 1000))
123 offset
= freq
- base
;
126 /* check that frequency is a 5MHz multiple from the base */
127 if (offset
!= (ch
* 5))
130 /* restricted channel range check for 2.4G */
131 if (start_factor
== WF_CHAN_FACTOR_2_4_G
&& (ch
< 1 || ch
> 13))
136 EXPORT_SYMBOL(brcmu_mhz2channel
);