drivers/staging/brcm80211/util/bcmwifi.c

   1 /*
   2  * Copyright (c) 2010 Broadcom Corporation
   3  *
   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.
   7  *
   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.
  15  */
  16
  17 #include <typedefs.h>
  18
  19 #include <osl.h>
  20 #include <linux/ctype.h>
  21 #include <linux/kernel.h>
  22 #include <bcmutils.h>
  23 #include <bcmwifi.h>
  24
  25 /*
  26  * Verify the chanspec is using a legal set of parameters, i.e. that the
  27  * chanspec specified a band, bw, ctl_sb and channel and that the
  28  * combination could be legal given any set of circumstances.
  29  * RETURNS: TRUE is the chanspec is malformed, false if it looks good.
  30  */
  31 bool wf_chspec_malformed(chanspec_t chanspec)
  32 {
  33         /* must be 2G or 5G band */
  34         if (!CHSPEC_IS5G(chanspec) && !CHSPEC_IS2G(chanspec))
  35                 return TRUE;
  36         /* must be 20 or 40 bandwidth */
  37         if (!CHSPEC_IS40(chanspec) && !CHSPEC_IS20(chanspec))
  38                 return TRUE;
  39
  40         /* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
  41         if (CHSPEC_IS20(chanspec)) {
  42                 if (!CHSPEC_SB_NONE(chanspec))
  43                         return TRUE;
  44         } else {
  45                 if (!CHSPEC_SB_UPPER(chanspec) && !CHSPEC_SB_LOWER(chanspec))
  46                         return TRUE;
  47         }
  48
  49         return FALSE;
  50 }
  51
  52 /*
  53  * This function returns the channel number that control traffic is being sent on, for legacy
  54  * channels this is just the channel number, for 40MHZ channels it is the upper or lowre 20MHZ
  55  * sideband depending on the chanspec selected
  56  */
  57 u8 wf_chspec_ctlchan(chanspec_t chspec)
  58 {
  59         u8 ctl_chan;
  60
  61         /* Is there a sideband ? */
  62         if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
  63                 return CHSPEC_CHANNEL(chspec);
  64         } else {
  65                 /* we only support 40MHZ with sidebands */
  66                 ASSERT(CHSPEC_BW(chspec) == WL_CHANSPEC_BW_40);
  67                 /* chanspec channel holds the centre frequency, use that and the
  68                  * side band information to reconstruct the control channel number
  69                  */
  70                 if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
  71                         /* control chan is the upper 20 MHZ SB of the 40MHZ channel */
  72                         ctl_chan = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
  73                 } else {
  74                         ASSERT(CHSPEC_CTL_SB(chspec) ==
  75                                WL_CHANSPEC_CTL_SB_LOWER);
  76                         /* control chan is the lower 20 MHZ SB of the 40MHZ channel */
  77                         ctl_chan = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
  78                 }
  79         }
  80
  81         return ctl_chan;
  82 }
  83
  84 chanspec_t wf_chspec_ctlchspec(chanspec_t chspec)
  85 {
  86         chanspec_t ctl_chspec = 0;
  87         u8 channel;
  88
  89         ASSERT(!wf_chspec_malformed(chspec));
  90
  91         /* Is there a sideband ? */
  92         if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
  93                 return chspec;
  94         } else {
  95                 if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
  96                         channel = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
  97                 } else {
  98                         channel = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
  99                 }
 100                 ctl_chspec =
 101                     channel | WL_CHANSPEC_BW_20 | WL_CHANSPEC_CTL_SB_NONE;
 102                 ctl_chspec |= CHSPEC_BAND(chspec);
 103         }
 104         return ctl_chspec;
 105 }
 106
 107 /*
 108  * Return the channel number for a given frequency and base frequency.
 109  * The returned channel number is relative to the given base frequency.
 110  * If the given base frequency is zero, a base frequency of 5 GHz is assumed for
 111  * frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
 112  *
 113  * Frequency is specified in MHz.
 114  * The base frequency is specified as (start_factor * 500 kHz).
 115  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
 116  * 2.4 GHz and 5 GHz bands.
 117  *
 118  * The returned channel will be in the range [1, 14] in the 2.4 GHz band
 119  * and [0, 200] otherwise.
 120  * -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
 121  * frequency is not a 2.4 GHz channel, or if the frequency is not and even
 122  * multiple of 5 MHz from the base frequency to the base plus 1 GHz.
 123  *
 124  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 125  */
 126 int wf_mhz2channel(uint freq, uint start_factor)
 127 {
 128         int ch = -1;
 129         uint base;
 130         int offset;
 131
 132         /* take the default channel start frequency */
 133         if (start_factor == 0) {
 134                 if (freq >= 2400 && freq <= 2500)
 135                         start_factor = WF_CHAN_FACTOR_2_4_G;
 136                 else if (freq >= 5000 && freq <= 6000)
 137                         start_factor = WF_CHAN_FACTOR_5_G;
 138         }
 139
 140         if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G)
 141                 return 14;
 142
 143         base = start_factor / 2;
 144
 145         /* check that the frequency is in 1GHz range of the base */
 146         if ((freq < base) || (freq > base + 1000))
 147                 return -1;
 148
 149         offset = freq - base;
 150         ch = offset / 5;
 151
 152         /* check that frequency is a 5MHz multiple from the base */
 153         if (offset != (ch * 5))
 154                 return -1;
 155
 156         /* restricted channel range check for 2.4G */
 157         if (start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 13))
 158                 return -1;
 159
 160         return ch;
 161 }
 162
 163 /*
 164  * Return the center frequency in MHz of the given channel and base frequency.
 165  * The channel number is interpreted relative to the given base frequency.
 166  *
 167  * The valid channel range is [1, 14] in the 2.4 GHz band and [0, 200] otherwise.
 168  * The base frequency is specified as (start_factor * 500 kHz).
 169  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_4_G, and WF_CHAN_FACTOR_5_G
 170  * are defined for 2.4 GHz, 4 GHz, and 5 GHz bands.
 171  * The channel range of [1, 14] is only checked for a start_factor of
 172  * WF_CHAN_FACTOR_2_4_G (4814 = 2407 * 2).
 173  * Odd start_factors produce channels on .5 MHz boundaries, in which case
 174  * the answer is rounded down to an integral MHz.
 175  * -1 is returned for an out of range channel.
 176  *
 177  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 178  */
 179 #ifdef BRCM_FULLMAC
 180 int wf_channel2mhz(uint ch, uint start_factor)
 181 {
 182         int freq;
 183
 184         if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
 185         (ch <= 200))
 186                 freq = -1;
 187         if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14))
 188                 freq = 2484;
 189         else
 190                 freq = ch * 5 + start_factor / 2;
 191
 192         return freq;
 193 }
 194 #else /* !BRCM_FULLMAC */
 195 int wf_channel2mhz(uint ch, uint start_factor)
 196 {
 197         int freq;
 198
 199         if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
 200             (ch > 200))
 201                 freq = -1;
 202         else if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14))
 203                 freq = 2484;
 204         else
 205                 freq = ch * 5 + start_factor / 2;
 206
 207         return freq;
 208 }
 209 #endif /* BRCM_FULLMAC */