release/src-rt/shared/bcmwifi.c

   1 /*
   2  * Misc utility routines used by kernel or app-level.
   3  * Contents are wifi-specific, used by any kernel or app-level
   4  * software that might want wifi things as it grows.
   5  *
   6  * Copyright (C) 2009, Broadcom Corporation
   7  * All Rights Reserved.
   8  *
   9  * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Broadcom Corporation;
  10  * the contents of this file may not be disclosed to third parties, copied
  11  * or duplicated in any form, in whole or in part, without the prior
  12  * written permission of Broadcom Corporation.
  13  * $Id: bcmwifi.c,v 1.22.4.1 2009/03/13 18:25:48 Exp $
  14  */
  15
  16 #include <typedefs.h>
  17
  18 #ifdef BCMDRIVER
  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 #else
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <ctype.h>
  27 #ifndef ASSERT
  28 #define ASSERT(exp)
  29 #endif
  30 #endif /* BCMDRIVER */
  31 #include <bcmwifi.h>
  32
  33 #if defined(WIN32) && defined(BCMDLL)
  34 #include <bcmstdlib.h>          /* For wl/exe/GNUmakefile.brcm_wlu */
  35 #endif
  36
  37 /* Chanspec ASCII representation:
  38  * <channel><band><bandwidth><ctl-sideband>
  39  *   digit   [AB]     [N]        [UL]
  40  *
  41  * <channel>: channel number of the 10MHz or 20MHz channel,
  42  *      or control sideband channel of 40MHz channel.
  43  * <band>: A for 5GHz, B for 2.4GHz
  44  * <bandwidth>: N for 10MHz, nothing for 20MHz or 40MHz
  45  *      (ctl-sideband spec implies 40MHz)
  46  * <ctl-sideband>: U for upper, L for lower
  47  *
  48  * <band> may be omitted on input, and will be assumed to be
  49  * 2.4GHz if channel number <= 14.
  50  *
  51  * Examples:
  52  *      8  ->  2.4GHz channel 8, 20MHz
  53  *      8b ->  2.4GHz channel 8, 20MHz
  54  *      8l ->  2.4GHz channel 8, 40MHz, lower ctl sideband
  55  *      8a ->  5GHz channel 8 (low 5 GHz band), 20MHz
  56  *      36 ->  5GHz channel 36, 20MHz
  57  *      36l -> 5GHz channel 36, 40MHz, lower ctl sideband
  58  *      40u -> 5GHz channel 40, 40MHz, upper ctl sideband
  59  *      180n -> channel 180, 10MHz
  60  */
  61
  62
  63 /* given a chanspec and a string buffer, format the chanspec as a
  64  * string, and return the original pointer a.
  65  * Min buffer length must be CHANSPEC_STR_LEN.
  66  * On error return NULL
  67  */
  68 char *
  69 wf_chspec_ntoa(chanspec_t chspec, char *buf)
  70 {
  71         const char *band, *bw, *sb;
  72         uint channel;
  73
  74         band = "";
  75         bw = "";
  76         sb = "";
  77         channel = CHSPEC_CHANNEL(chspec);
  78         /* check for non-default band spec */
  79         if ((CHSPEC_IS2G(chspec) && channel > CH_MAX_2G_CHANNEL) ||
  80             (CHSPEC_IS5G(chspec) && channel <= CH_MAX_2G_CHANNEL))
  81                 band = (CHSPEC_IS2G(chspec)) ? "b" : "a";
  82         if (CHSPEC_IS40(chspec)) {
  83                 if (CHSPEC_SB_UPPER(chspec)) {
  84                         sb = "u";
  85                         channel += CH_10MHZ_APART;
  86                 } else {
  87                         sb = "l";
  88                         channel -= CH_10MHZ_APART;
  89                 }
  90         } else if (CHSPEC_IS10(chspec)) {
  91                 bw = "n";
  92         }
  93
  94         /* Outputs a max of 6 chars including '\0'  */
  95         snprintf(buf, 6, "%d%s%s%s", channel, band, bw, sb);
  96         return (buf);
  97 }
  98
  99 /* given a chanspec string, convert to a chanspec.
 100  * On error return 0
 101  */
 102 chanspec_t
 103 wf_chspec_aton(char *a)
 104 {
 105         char *endp;
 106         uint channel, band, bw, ctl_sb;
 107         char c;
 108
 109         channel = strtoul(a, &endp, 10);
 110
 111         /* check for no digits parsed */
 112         if (endp == a)
 113                 return 0;
 114
 115         if (channel > MAXCHANNEL)
 116                 return 0;
 117
 118         band = ((channel <= CH_MAX_2G_CHANNEL) ? WL_CHANSPEC_BAND_2G : WL_CHANSPEC_BAND_5G);
 119         bw = WL_CHANSPEC_BW_20;
 120         ctl_sb = WL_CHANSPEC_CTL_SB_NONE;
 121
 122         a = endp;
 123
 124         c = tolower(a[0]);
 125         if (c == '\0')
 126                 goto done;
 127
 128         /* parse the optional ['A' | 'B'] band spec */
 129         if (c == 'a' || c == 'b') {
 130                 band = (c == 'a') ? WL_CHANSPEC_BAND_5G : WL_CHANSPEC_BAND_2G;
 131                 a++;
 132                 c = tolower(a[0]);
 133                 if (c == '\0')
 134                         goto done;
 135         }
 136
 137         /* parse bandwidth 'N' (10MHz) or 40MHz ctl sideband ['L' | 'U'] */
 138         if (c == 'n') {
 139                 bw = WL_CHANSPEC_BW_10;
 140         } else if (c == 'l') {
 141                 bw = WL_CHANSPEC_BW_40;
 142                 ctl_sb = WL_CHANSPEC_CTL_SB_LOWER;
 143                 /* adjust channel to center of 40MHz band */
 144                 if (channel <= (MAXCHANNEL - CH_20MHZ_APART))
 145                         channel += CH_10MHZ_APART;
 146                 else
 147                         return 0;
 148         } else if (c == 'u') {
 149                 bw = WL_CHANSPEC_BW_40;
 150                 ctl_sb = WL_CHANSPEC_CTL_SB_UPPER;
 151                 /* adjust channel to center of 40MHz band */
 152                 if (channel > CH_20MHZ_APART)
 153                         channel -= CH_10MHZ_APART;
 154                 else
 155                         return 0;
 156         } else {
 157                 return 0;
 158         }
 159
 160 done:
 161         return (channel | band | bw | ctl_sb);
 162 }
 163
 164 /*
 165  * Verify the chanspec is using a legal set of parameters, i.e. that the
 166  * chanspec specified a band, bw, ctl_sb and channel and that the
 167  * combination could be legal given any set of circumstances.
 168  * RETURNS: TRUE is the chanspec is malformed, false if it looks good.
 169  */
 170 bool
 171 wf_chspec_malformed(chanspec_t chanspec)
 172 {
 173         /* must be 2G or 5G band */
 174         if (!CHSPEC_IS5G(chanspec) && !CHSPEC_IS2G(chanspec))
 175                 return TRUE;
 176         /* must be 20 or 40 bandwidth */
 177         if (!CHSPEC_IS40(chanspec) && !CHSPEC_IS20(chanspec))
 178                 return TRUE;
 179
 180         /* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
 181         if (CHSPEC_IS20(chanspec)) {
 182                 if (!CHSPEC_SB_NONE(chanspec))
 183                         return TRUE;
 184         } else {
 185                 if (!CHSPEC_SB_UPPER(chanspec) && !CHSPEC_SB_LOWER(chanspec))
 186                 return TRUE;
 187         }
 188
 189         return FALSE;
 190 }
 191
 192 /*
 193  * This function returns the channel number that control traffic is being sent on, for legacy
 194  * channels this is just the channel number, for 40MHZ channels it is the upper or lowre 20MHZ
 195  * sideband depending on the chanspec selected
 196  */
 197 uint8
 198 wf_chspec_ctlchan(chanspec_t chspec)
 199 {
 200         uint8 ctl_chan;
 201
 202         /* Is there a sideband ? */
 203         if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
 204                 return CHSPEC_CHANNEL(chspec);
 205         } else {
 206                 /* we only support 40MHZ with sidebands */
 207                 ASSERT(CHSPEC_BW(chspec) == WL_CHANSPEC_BW_40);
 208                 /* chanspec channel holds the centre frequency, use that and the
 209                  * side band information to reconstruct the control channel number
 210                  */
 211                 if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
 212                         /* control chan is the upper 20 MHZ SB of the 40MHZ channel */
 213                         ctl_chan = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
 214                 } else {
 215                         ASSERT(CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_LOWER);
 216                         /* control chan is the lower 20 MHZ SB of the 40MHZ channel */
 217                         ctl_chan = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
 218                 }
 219         }
 220
 221         return ctl_chan;
 222 }
 223
 224 /*
 225  * Return the channel number for a given frequency and base frequency.
 226  * The returned channel number is relative to the given base frequency.
 227  * If the given base frequency is zero, a base frequency of 5 GHz is assumed for
 228  * frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
 229  *
 230  * Frequency is specified in MHz.
 231  * The base frequency is specified as (start_factor * 500 kHz).
 232  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
 233  * 2.4 GHz and 5 GHz bands.
 234  *
 235  * The returned channel will be in the range [1, 14] in the 2.4 GHz band
 236  * and [0, 200] otherwise.
 237  * -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
 238  * frequency is not a 2.4 GHz channel, or if the frequency is not and even
 239  * multiple of 5 MHz from the base frequency to the base plus 1 GHz.
 240  *
 241  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 242  */
 243 int
 244 wf_mhz2channel(uint freq, uint start_factor)
 245 {
 246         int ch = -1;
 247         uint base;
 248         int offset;
 249
 250         /* take the default channel start frequency */
 251         if (start_factor == 0) {
 252                 if (freq >= 2400 && freq <= 2500)
 253                         start_factor = WF_CHAN_FACTOR_2_4_G;
 254                 else if (freq >= 5000 && freq <= 6000)
 255                         start_factor = WF_CHAN_FACTOR_5_G;
 256         }
 257
 258         if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G)
 259                 return 14;
 260
 261         base = start_factor / 2;
 262
 263         /* check that the frequency is in 1GHz range of the base */
 264         if ((freq < base) || (freq > base + 1000))
 265                 return -1;
 266
 267         offset = freq - base;
 268         ch = offset / 5;
 269
 270         /* check that frequency is a 5MHz multiple from the base */
 271         if (offset != (ch * 5))
 272                 return -1;
 273
 274         /* restricted channel range check for 2.4G */
 275         if (start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 13))
 276                 return -1;
 277
 278         return ch;
 279 }
 280
 281 /*
 282  * Return the center frequency in MHz of the given channel and base frequency.
 283  * The channel number is interpreted relative to the given base frequency.
 284  *
 285  * The valid channel range is [1, 14] in the 2.4 GHz band and [0, 200] otherwise.
 286  * The base frequency is specified as (start_factor * 500 kHz).
 287  * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
 288  * 2.4 GHz and 5 GHz bands.
 289  * The channel range of [1, 14] is only checked for a start_factor of
 290  * WF_CHAN_FACTOR_2_4_G (4814).
 291  * Odd start_factors produce channels on .5 MHz boundaries, in which case
 292  * the answer is rounded down to an integral MHz.
 293  * -1 is returned for an out of range channel.
 294  *
 295  * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
 296  */
 297 int
 298 wf_channel2mhz(uint ch, uint start_factor)
 299 {
 300         int freq;
 301
 302         if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
 303             (ch <= 200))
 304                 freq = -1;
 305         if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14))
 306                 freq = 2484;
 307         else
 308                 freq = ch * 5 + start_factor / 2;
 309
 310         return freq;
 311 }