drivers/net/wireless/zd1211rw/zd_ieee80211.c

   1 /* ZD1211 USB-WLAN driver for Linux
   2  *
   3  * Copyright (C) 2005-2007 Ulrich Kunitz <kune@deine-taler.de>
   4  * Copyright (C) 2006-2007 Daniel Drake <dsd@gentoo.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 /*
  22  * In the long term, we'll probably find a better way of handling regulatory
  23  * requirements outside of the driver.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <net/mac80211.h>
  28
  29 #include "zd_ieee80211.h"
  30 #include "zd_mac.h"
  31
  32 struct channel_range {
  33         u8 regdomain;
  34         u8 start;
  35         u8 end; /* exclusive (channel must be less than end) */
  36 };
  37
  38 static const struct channel_range channel_ranges[] = {
  39         { ZD_REGDOMAIN_FCC,             1, 12 },
  40         { ZD_REGDOMAIN_IC,              1, 12 },
  41         { ZD_REGDOMAIN_ETSI,            1, 14 },
  42         { ZD_REGDOMAIN_JAPAN,           1, 14 },
  43         { ZD_REGDOMAIN_SPAIN,           1, 14 },
  44         { ZD_REGDOMAIN_FRANCE,          1, 14 },
  45
  46         /* Japan originally only had channel 14 available (see CHNL_ID 0x40 in
  47          * 802.11). However, in 2001 the range was extended to include channels
  48          * 1-13. The ZyDAS devices still use the old region code but are
  49          * designed to allow the extra channel access in Japan. */
  50         { ZD_REGDOMAIN_JAPAN_ADD,       1, 15 },
  51 };
  52
  53 static const struct channel_range *zd_channel_range(u8 regdomain)
  54 {
  55         int i;
  56         for (i = 0; i < ARRAY_SIZE(channel_ranges); i++) {
  57                 const struct channel_range *range = &channel_ranges[i];
  58                 if (range->regdomain == regdomain)
  59                         return range;
  60         }
  61         return NULL;
  62 }
  63
  64 #define CHAN_TO_IDX(chan) ((chan) - 1)
  65
  66 static void unmask_bg_channels(struct ieee80211_hw *hw,
  67         const struct channel_range *range,
  68         struct ieee80211_supported_band *sband)
  69 {
  70         u8 channel;
  71
  72         for (channel = range->start; channel < range->end; channel++) {
  73                 struct ieee80211_channel *chan =
  74                         &sband->channels[CHAN_TO_IDX(channel)];
  75                 chan->flags = 0;
  76         }
  77 }
  78
  79 void zd_geo_init(struct ieee80211_hw *hw, u8 regdomain)
  80 {
  81         struct zd_mac *mac = zd_hw_mac(hw);
  82         const struct channel_range *range;
  83
  84         dev_dbg(zd_mac_dev(mac), "regdomain %#02x\n", regdomain);
  85
  86         range = zd_channel_range(regdomain);
  87         if (!range) {
  88                 /* The vendor driver overrides the regulatory domain and
  89                  * allowed channel registers and unconditionally restricts
  90                  * available channels to 1-11 everywhere. Match their
  91                  * questionable behaviour only for regdomains which we don't
  92                  * recognise. */
  93                 dev_warn(zd_mac_dev(mac), "Unrecognised regulatory domain: "
  94                         "%#02x. Defaulting to FCC.\n", regdomain);
  95                 range = zd_channel_range(ZD_REGDOMAIN_FCC);
  96         }
  97
  98         unmask_bg_channels(hw, range, &mac->band);
  99 }
 100