1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/*
* Copyright (c) 2010 Broadcom Corporation
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <bcmdefs.h>
#include <bcmutils.h>
#include <bcmwifi.h>
/*
* Verify the chanspec is using a legal set of parameters, i.e. that the
* chanspec specified a band, bw, ctl_sb and channel and that the
* combination could be legal given any set of circumstances.
* RETURNS: true is the chanspec is malformed, false if it looks good.
*/
bool bcm_chspec_malformed(chanspec_t chanspec)
{
/* must be 2G or 5G band */
if (!CHSPEC_IS5G(chanspec) && !CHSPEC_IS2G(chanspec))
return true;
/* must be 20 or 40 bandwidth */
if (!CHSPEC_IS40(chanspec) && !CHSPEC_IS20(chanspec))
return true;
/* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
if (CHSPEC_IS20(chanspec)) {
if (!CHSPEC_SB_NONE(chanspec))
return true;
} else {
if (!CHSPEC_SB_UPPER(chanspec) && !CHSPEC_SB_LOWER(chanspec))
return true;
}
return false;
}
EXPORT_SYMBOL(bcm_chspec_malformed);
/*
* This function returns the channel number that control traffic is being sent on, for legacy
* channels this is just the channel number, for 40MHZ channels it is the upper or lowre 20MHZ
* sideband depending on the chanspec selected
*/
u8 bcm_chspec_ctlchan(chanspec_t chspec)
{
u8 ctl_chan;
/* Is there a sideband ? */
if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
return CHSPEC_CHANNEL(chspec);
} else {
/* we only support 40MHZ with sidebands */
/* chanspec channel holds the centre frequency, use that and the
* side band information to reconstruct the control channel number
*/
if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
/* control chan is the upper 20 MHZ SB of the 40MHZ channel */
ctl_chan = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
} else {
/* control chan is the lower 20 MHZ SB of the 40MHZ channel */
ctl_chan = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
}
}
return ctl_chan;
}
EXPORT_SYMBOL(bcm_chspec_ctlchan);
/*
* Return the channel number for a given frequency and base frequency.
* The returned channel number is relative to the given base frequency.
* If the given base frequency is zero, a base frequency of 5 GHz is assumed for
* frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
*
* Frequency is specified in MHz.
* The base frequency is specified as (start_factor * 500 kHz).
* Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
* 2.4 GHz and 5 GHz bands.
*
* The returned channel will be in the range [1, 14] in the 2.4 GHz band
* and [0, 200] otherwise.
* -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
* frequency is not a 2.4 GHz channel, or if the frequency is not and even
* multiple of 5 MHz from the base frequency to the base plus 1 GHz.
*
* Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
*/
int bcm_mhz2channel(uint freq, uint start_factor)
{
int ch = -1;
uint base;
int offset;
/* take the default channel start frequency */
if (start_factor == 0) {
if (freq >= 2400 && freq <= 2500)
start_factor = WF_CHAN_FACTOR_2_4_G;
else if (freq >= 5000 && freq <= 6000)
start_factor = WF_CHAN_FACTOR_5_G;
}
if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G)
return 14;
base = start_factor / 2;
/* check that the frequency is in 1GHz range of the base */
if ((freq < base) || (freq > base + 1000))
return -1;
offset = freq - base;
ch = offset / 5;
/* check that frequency is a 5MHz multiple from the base */
if (offset != (ch * 5))
return -1;
/* restricted channel range check for 2.4G */
if (start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 13))
return -1;
return ch;
}
EXPORT_SYMBOL(bcm_mhz2channel);
|
