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 <bcmutils.h>
  21 #define strtoul(nptr, endptr, base) bcm_strtoul((nptr), (endptr), (base))
  22 #define tolower(c) (bcm_isupper((c)) ? ((c) + 'a' - 'A') : (c))
  23 #include <bcmwifi.h>
  24
  25 /* Chanspec ASCII representation:
  26  * <channel><band><bandwidth><ctl-sideband>
  27  *   digit   [AB]     [N]        [UL]
  28  *
  29  * <channel>: channel number of the 10MHz or 20MHz channel,
  30  *      or control sideband channel of 40MHz channel.
  31  * <band>: A for 5GHz, B for 2.4GHz
  32  * <bandwidth>: N for 10MHz, nothing for 20MHz or 40MHz
  33  *      (ctl-sideband spec implies 40MHz)
  34  * <ctl-sideband>: U for upper, L for lower
  35  *
  36  * <band> may be omitted on input, and will be assumed to be
  37  * 2.4GHz if channel number <= 14.
  38  *
  39  * Examples:
  40  *      8  ->  2.4GHz channel 8, 20MHz
  41  *      8b ->  2.4GHz channel 8, 20MHz
  42  *      8l ->  2.4GHz channel 8, 40MHz, lower ctl sideband
  43  *      8a ->  5GHz channel 8 (low 5 GHz band), 20MHz
  44  *      36 ->  5GHz channel 36, 20MHz
  45  *      36l -> 5GHz channel 36, 40MHz, lower ctl sideband
  46  *      40u -> 5GHz channel 40, 40MHz, upper ctl sideband
  47  *      180n -> channel 180, 10MHz
  48  */
  49
  50 /* given a chanspec and a string buffer, format the chanspec as a
  51  * string, and return the original pointer a.
  52  * Min buffer length must be CHANSPEC_STR_LEN.
  53  * On error return NULL
  54  */
  55 char *wf_chspec_ntoa(chanspec_t chspec, char *buf)
  56 {
  57         const char *band, *bw, *sb;
  58         uint channel;
  59
  60         band = "";
  61         bw = "";
  62         sb = "";
  63         channel = CHSPEC_CHANNEL(chspec);
  64         /* check for non-default band spec */
  65         if ((CHSPEC_IS2G(chspec) && channel > CH_MAX_2G_CHANNEL) ||
  66             (CHSPEC_IS5G(chspec) && channel <= CH_MAX_2G_CHANNEL))
  67                 band = (CHSPEC_IS2G(chspec)) ? "b" : "a";
  68         if (CHSPEC_IS40(chspec)) {
  69                 if (CHSPEC_SB_UPPER(chspec)) {
  70                         sb = "u";
  71                         channel += CH_10MHZ_APART;
  72                 } else {
  73                         sb = "l";
  74                         channel -= CH_10MHZ_APART;
  75                 }
  76         } else if (CHSPEC_IS10(chspec)) {
  77                 bw = "n";
  78         }
  79
  80         /* Outputs a max of 6 chars including '\0'  */
  81         snprintf(buf, 6, "%d%s%s%s", channel, band, bw, sb);
  82         return (buf);
  83 }
  84
  85 /* given a chanspec string, convert to a chanspec.
  86  * On error return 0
  87  */
  88 chanspec_t wf_chspec_aton(char *a)
  89 {
  90         char *endp = NULL;
  91         uint channel, band, bw, ctl_sb;
  92         char c;
  93
  94         channel = strtoul(a, &endp, 10);
  95
  96         /* check for no digits parsed */
  97         if (endp == a)
  98                 return 0;
  99
 100         if (channel > MAXCHANNEL)
 101                 return 0;
 102
 103         band =
 104             ((channel <=
 105               CH_MAX_2G_CHANNEL) ? WL_CHANSPEC_BAND_2G : WL_CHANSPEC_BAND_5G);
 106         bw = WL_CHANSPEC_BW_20;
 107         ctl_sb = WL_CHANSPEC_CTL_SB_NONE;
 108
 109         a = endp;
 110
 111         c = tolower(a[0]);
 112         if (c == '\0')
 113                 goto done;
 114
 115         /* parse the optional ['A' | 'B'] band spec */
 116         if (c == 'a' || c == 'b') {
 117                 band = (c == 'a') ? WL_CHANSPEC_BAND_5G : WL_CHANSPEC_BAND_2G;
 118                 a++;
 119                 c = tolower(a[0]);
 120                 if (c == '\0')
 121                         goto done;
 122         }
 123
 124         /* parse bandwidth 'N' (10MHz) or 40MHz ctl sideband ['L' | 'U'] */
 125         if (c == 'n') {
 126                 bw = WL_CHANSPEC_BW_10;
 127         } else if (c == 'l') {
 128                 bw = WL_CHANSPEC_BW_40;
 129                 ctl_sb = WL_CHANSPEC_CTL_SB_LOWER;
 130                 /* adjust channel to center of 40MHz band */
 131                 if (channel <= (MAXCHANNEL - CH_20MHZ_APART))
 132                         channel += CH_10MHZ_APART;
 133                 else
 134                         return 0;
 135         } else if (c == 'u') {
 136                 bw = WL_CHANSPEC_BW_40;
 137                 ctl_sb = WL_CHANSPEC_CTL_SB_UPPER;
 138                 /* adjust channel to center of 40MHz band */
 139                 if (channel > CH_20MHZ_APART)
 140                         channel -= CH_10MHZ_APART;
 141                 else
 142                         return 0;
 143         } else {
 144                 return 0;
 145         }
 146
 147  done:
 148         return (channel | band | bw | ctl_sb);
 149 }
 150
 151 /*
 152  * Verify the chanspec is using a legal set of parameters, i.e. that the
 153  * chanspec specified a band, bw, ctl_sb and channel and that the
 154  * combination could be legal given any set of circumstances.
 155  * RETURNS: TRUE is the chanspec is malformed, false if it looks good.
 156  */
 157 bool wf_chspec_malformed(chanspec_t chanspec)
 158 {
 159         /* must be 2G or 5G band */
 160         if (!CHSPEC_IS5G(chanspec) && !CHSPEC_IS2G(chanspec))
 161                 return TRUE;
 162         /* must be 20 or 40 bandwidth */
 163         if (!CHSPEC_IS40(chanspec) && !CHSPEC_IS20(chanspec))
 164                 return TRUE;
 165
 166         /* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
 167         if (CHSPEC_IS20(chanspec)) {
 168                 if (!CHSPEC_SB_NONE(chanspec))
 169                         return TRUE;
 170         } else {
 171                 if (!CHSPEC_SB_UPPER(chanspec) && !CHSPEC_SB_LOWER(chanspec))
 172                         return TRUE;
 173         }
 174
 175         return FALSE;
 176 }
 177
 178 /*
 179  * This function returns the channel number that control traffic is being sent on, for legacy
 180  * channels this is just the channel number, for 40MHZ channels it is the upper or lowre 20MHZ
 181  * sideband depending on the chanspec selected
 182  */
 183 uint8 wf_chspec_ctlchan(chanspec_t chspec)
 184 {
 185         uint8 ctl_chan;
 186
 187         /* Is there a sideband ? */
 188         if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
 189                 return CHSPEC_CHANNEL(chspec);
 190         } else {
 191                 /* we only support 40MHZ with sidebands */
 192                 ASSERT(CHSPEC_BW(chspec) == WL_CHANSPEC_BW_40);
 193                 /* chanspec channel holds the centre frequency, use that and the
 194                  * side band information to reconstruct the control channel number
 195                  */
 196                 if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
 197                         /* control chan is the upper 20 MHZ SB of the 40MHZ channel */
 198                         ctl_chan = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
 199                 } else {
 200                         ASSERT(CHSPEC_CTL_SB(chspec) ==
 201                                WL_CHANSPEC_CTL_SB_LOWER);
 202                         /* control chan is the lower 20 MHZ SB of the 40MHZ channel */
 203                         ctl_chan = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
 204                 }
 205         }
 206
 207         return ctl_chan;
 208 }
 209
 210 chanspec_t wf_chspec_ctlchspec(chanspec_t chspec)
 211 {
 212         chanspec_t ctl_chspec = 0;
 213         uint8 channel;
 214
 215         ASSERT(!wf_chspec_malformed(chspec));
 216
 217         /* Is there a sideband ? */
 218         if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
 219                 return chspec;
 220         } else {
 221                 if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
 222                         channel = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
 223                 } else {
 224                         channel = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
 225                 }
 226                 ctl_chspec =
 227                     channel | WL_CHANSPEC_BW_20 | WL_CHANSPEC_CTL_SB_NONE;
 228                 ctl_chspec |= CHSPEC_BAND(chspec);
 229         }
 230         return ctl_chspec;
 231 }
 232
 233 /*
 234  * Return the channel number for a given frequency and base frequency.
 235  * The returned channel number is relative to the given base frequency.
 236  * If the given base frequency is zero, a base frequency of 5 GHz is assumed for
 237  * frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
 238  *
 239  * Frequency is specified in MHz.
 240  * The base frequency is specified as (start_factor * 500 kHz).
 241  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
 242  * 2.4 GHz and 5 GHz bands.
 243  *
 244  * The returned channel will be in the range [1, 14] in the 2.4 GHz band
 245  * and [0, 200] otherwise.
 246  * -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
 247  * frequency is not a 2.4 GHz channel, or if the frequency is not and even
 248  * multiple of 5 MHz from the base frequency to the base plus 1 GHz.
 249  *
 250  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 251  */
 252 int wf_mhz2channel(uint freq, uint start_factor)
 253 {
 254         int ch = -1;
 255         uint base;
 256         int offset;
 257
 258         /* take the default channel start frequency */
 259         if (start_factor == 0) {
 260                 if (freq >= 2400 && freq <= 2500)
 261                         start_factor = WF_CHAN_FACTOR_2_4_G;
 262                 else if (freq >= 5000 && freq <= 6000)
 263                         start_factor = WF_CHAN_FACTOR_5_G;
 264         }
 265
 266         if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G)
 267                 return 14;
 268
 269         base = start_factor / 2;
 270
 271         /* check that the frequency is in 1GHz range of the base */
 272         if ((freq < base) || (freq > base + 1000))
 273                 return -1;
 274
 275         offset = freq - base;
 276         ch = offset / 5;
 277
 278         /* check that frequency is a 5MHz multiple from the base */
 279         if (offset != (ch * 5))
 280                 return -1;
 281
 282         /* restricted channel range check for 2.4G */
 283         if (start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 13))
 284                 return -1;
 285
 286         return ch;
 287 }
 288
 289 /*
 290  * Return the center frequency in MHz of the given channel and base frequency.
 291  * The channel number is interpreted relative to the given base frequency.
 292  *
 293  * The valid channel range is [1, 14] in the 2.4 GHz band and [0, 200] otherwise.
 294  * The base frequency is specified as (start_factor * 500 kHz).
 295  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_4_G, and WF_CHAN_FACTOR_5_G
 296  * are defined for 2.4 GHz, 4 GHz, and 5 GHz bands.
 297  * The channel range of [1, 14] is only checked for a start_factor of
 298  * WF_CHAN_FACTOR_2_4_G (4814 = 2407 * 2).
 299  * Odd start_factors produce channels on .5 MHz boundaries, in which case
 300  * the answer is rounded down to an integral MHz.
 301  * -1 is returned for an out of range channel.
 302  *
 303  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 304  */
 305 int wf_channel2mhz(uint ch, uint start_factor)
 306 {
 307         int freq;
 308
 309         if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
 310             (ch > 200))
 311                 freq = -1;
 312         else if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14))
 313                 freq = 2484;
 314         else
 315                 freq = ch * 5 + start_factor / 2;
 316
 317         return freq;
 318 }