net/wireless/util.c

   1 /*
   2  * Wireless utility functions
   3  *
   4  * Copyright 2007-2009  Johannes Berg <johannes@sipsolutions.net>
   5  */
   6 #include <linux/bitops.h>
   7 #include <net/cfg80211.h>
   8 #include "core.h"
   9
  10 struct ieee80211_rate *
  11 ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
  12                             u32 basic_rates, int bitrate)
  13 {
  14         struct ieee80211_rate *result = &sband->bitrates[0];
  15         int i;
  16
  17         for (i = 0; i < sband->n_bitrates; i++) {
  18                 if (!(basic_rates & BIT(i)))
  19                         continue;
  20                 if (sband->bitrates[i].bitrate > bitrate)
  21                         continue;
  22                 result = &sband->bitrates[i];
  23         }
  24
  25         return result;
  26 }
  27 EXPORT_SYMBOL(ieee80211_get_response_rate);
  28
  29 int ieee80211_channel_to_frequency(int chan)
  30 {
  31         if (chan < 14)
  32                 return 2407 + chan * 5;
  33
  34         if (chan == 14)
  35                 return 2484;
  36
  37         /* FIXME: 802.11j 17.3.8.3.2 */
  38         return (chan + 1000) * 5;
  39 }
  40 EXPORT_SYMBOL(ieee80211_channel_to_frequency);
  41
  42 int ieee80211_frequency_to_channel(int freq)
  43 {
  44         if (freq == 2484)
  45                 return 14;
  46
  47         if (freq < 2484)
  48                 return (freq - 2407) / 5;
  49
  50         /* FIXME: 802.11j 17.3.8.3.2 */
  51         return freq/5 - 1000;
  52 }
  53 EXPORT_SYMBOL(ieee80211_frequency_to_channel);
  54
  55 struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
  56                                                   int freq)
  57 {
  58         enum ieee80211_band band;
  59         struct ieee80211_supported_band *sband;
  60         int i;
  61
  62         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
  63                 sband = wiphy->bands[band];
  64
  65                 if (!sband)
  66                         continue;
  67
  68                 for (i = 0; i < sband->n_channels; i++) {
  69                         if (sband->channels[i].center_freq == freq)
  70                                 return &sband->channels[i];
  71                 }
  72         }
  73
  74         return NULL;
  75 }
  76 EXPORT_SYMBOL(__ieee80211_get_channel);
  77
  78 static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
  79                                      enum ieee80211_band band)
  80 {
  81         int i, want;
  82
  83         switch (band) {
  84         case IEEE80211_BAND_5GHZ:
  85                 want = 3;
  86                 for (i = 0; i < sband->n_bitrates; i++) {
  87                         if (sband->bitrates[i].bitrate == 60 ||
  88                             sband->bitrates[i].bitrate == 120 ||
  89                             sband->bitrates[i].bitrate == 240) {
  90                                 sband->bitrates[i].flags |=
  91                                         IEEE80211_RATE_MANDATORY_A;
  92                                 want--;
  93                         }
  94                 }
  95                 WARN_ON(want);
  96                 break;
  97         case IEEE80211_BAND_2GHZ:
  98                 want = 7;
  99                 for (i = 0; i < sband->n_bitrates; i++) {
 100                         if (sband->bitrates[i].bitrate == 10) {
 101                                 sband->bitrates[i].flags |=
 102                                         IEEE80211_RATE_MANDATORY_B |
 103                                         IEEE80211_RATE_MANDATORY_G;
 104                                 want--;
 105                         }
 106
 107                         if (sband->bitrates[i].bitrate == 20 ||
 108                             sband->bitrates[i].bitrate == 55 ||
 109                             sband->bitrates[i].bitrate == 110 ||
 110                             sband->bitrates[i].bitrate == 60 ||
 111                             sband->bitrates[i].bitrate == 120 ||
 112                             sband->bitrates[i].bitrate == 240) {
 113                                 sband->bitrates[i].flags |=
 114                                         IEEE80211_RATE_MANDATORY_G;
 115                                 want--;
 116                         }
 117
 118                         if (sband->bitrates[i].bitrate != 10 &&
 119                             sband->bitrates[i].bitrate != 20 &&
 120                             sband->bitrates[i].bitrate != 55 &&
 121                             sband->bitrates[i].bitrate != 110)
 122                                 sband->bitrates[i].flags |=
 123                                         IEEE80211_RATE_ERP_G;
 124                 }
 125                 WARN_ON(want != 0 && want != 3 && want != 6);
 126                 break;
 127         case IEEE80211_NUM_BANDS:
 128                 WARN_ON(1);
 129                 break;
 130         }
 131 }
 132
 133 void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
 134 {
 135         enum ieee80211_band band;
 136
 137         for (band = 0; band < IEEE80211_NUM_BANDS; band++)
 138                 if (wiphy->bands[band])
 139                         set_mandatory_flags_band(wiphy->bands[band], band);
 140 }