1/* zd_ieee80211.c 2 * 3 * This program is free software; you can redistribute it and/or modify 4 * it under the terms of the GNU General Public License as published by 5 * the Free Software Foundation; either version 2 of the License, or 6 * (at your option) any later version. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 16 */ 17 18/* 19 * A lot of this code is generic and should be moved into the upper layers 20 * at some point. 21 */ 22 23#include <linux/errno.h> 24#include <linux/wireless.h> 25#include <linux/kernel.h> 26#include <net/ieee80211.h> 27 28#include "zd_def.h" 29#include "zd_ieee80211.h" 30#include "zd_mac.h" 31 32static const struct channel_range channel_ranges[] = { 33 [0] = { 0, 0}, 34 [ZD_REGDOMAIN_FCC] = { 1, 12}, 35 [ZD_REGDOMAIN_IC] = { 1, 12}, 36 [ZD_REGDOMAIN_ETSI] = { 1, 14}, 37 [ZD_REGDOMAIN_JAPAN] = { 1, 14}, 38 [ZD_REGDOMAIN_SPAIN] = { 1, 14}, 39 [ZD_REGDOMAIN_FRANCE] = { 1, 14}, 40 41 /* Japan originally only had channel 14 available (see CHNL_ID 0x40 in 42 * 802.11). However, in 2001 the range was extended to include channels 43 * 1-13. The ZyDAS devices still use the old region code but are 44 * designed to allow the extra channel access in Japan. */ 45 [ZD_REGDOMAIN_JAPAN_ADD] = { 1, 15}, 46}; 47 48const struct channel_range *zd_channel_range(u8 regdomain) 49{ 50 if (regdomain >= ARRAY_SIZE(channel_ranges)) 51 regdomain = 0; 52 return &channel_ranges[regdomain]; 53} 54 55int zd_regdomain_supports_channel(u8 regdomain, u8 channel) 56{ 57 const struct channel_range *range = zd_channel_range(regdomain); 58 return range->start <= channel && channel < range->end; 59} 60 61int zd_regdomain_supported(u8 regdomain) 62{ 63 const struct channel_range *range = zd_channel_range(regdomain); 64 return range->start != 0; 65} 66 67/* Stores channel frequencies in MHz. */ 68static const u16 channel_frequencies[] = { 69 2412, 2417, 2422, 2427, 2432, 2437, 2442, 2447, 70 2452, 2457, 2462, 2467, 2472, 2484, 71}; 72 73#define NUM_CHANNELS ARRAY_SIZE(channel_frequencies) 74 75static int compute_freq(struct iw_freq *freq, u32 mhz, u32 hz) 76{ 77 u32 factor; 78 79 freq->e = 0; 80 if (mhz >= 1000000000U) { 81 pr_debug("zd1211 mhz %u to large\n", mhz); 82 freq->m = 0; 83 return -EINVAL; 84 } 85 86 factor = 1000; 87 while (mhz >= factor) { 88 89 freq->e += 1; 90 factor *= 10; 91 } 92 93 factor /= 1000U; 94 freq->m = mhz * (1000000U/factor) + hz/factor; 95 96 return 0; 97} 98 99int zd_channel_to_freq(struct iw_freq *freq, u8 channel) 100{ 101 if (channel > NUM_CHANNELS) { 102 freq->m = 0; 103 freq->e = 0; 104 return -EINVAL; 105 } 106 if (!channel) { 107 freq->m = 0; 108 freq->e = 0; 109 return -EINVAL; 110 } 111 return compute_freq(freq, channel_frequencies[channel-1], 0); 112} 113 114static int freq_to_mhz(const struct iw_freq *freq) 115{ 116 u32 factor; 117 int e; 118 119 /* Such high frequencies are not supported. */ 120 if (freq->e > 6) 121 return -EINVAL; 122 123 factor = 1; 124 for (e = freq->e; e > 0; --e) { 125 factor *= 10; 126 } 127 factor = 1000000U / factor; 128 129 if (freq->m % factor) { 130 return -EINVAL; 131 } 132 133 return freq->m / factor; 134} 135 136int zd_find_channel(u8 *channel, const struct iw_freq *freq) 137{ 138 int i, r; 139 u32 mhz; 140 141 if (freq->m < 1000) { 142 if (freq->m > NUM_CHANNELS || freq->m == 0) 143 return -EINVAL; 144 *channel = freq->m; 145 return 1; 146 } 147 148 r = freq_to_mhz(freq); 149 if (r < 0) 150 return r; 151 mhz = r; 152 153 for (i = 0; i < NUM_CHANNELS; i++) { 154 if (mhz == channel_frequencies[i]) { 155 *channel = i+1; 156 return 1; 157 } 158 } 159 160 return -EINVAL; 161} 162 163int zd_geo_init(struct ieee80211_device *ieee, u8 regdomain) 164{ 165 struct ieee80211_geo geo; 166 const struct channel_range *range; 167 int i; 168 u8 channel; 169 170 dev_dbg(zd_mac_dev(zd_netdev_mac(ieee->dev)), 171 "regdomain %#04x\n", regdomain); 172 173 range = zd_channel_range(regdomain); 174 if (range->start == 0) { 175 dev_err(zd_mac_dev(zd_netdev_mac(ieee->dev)), 176 "zd1211 regdomain %#04x not supported\n", 177 regdomain); 178 return -EINVAL; 179 } 180 181 memset(&geo, 0, sizeof(geo)); 182 183 for (i = 0, channel = range->start; channel < range->end; channel++) { 184 struct ieee80211_channel *chan = &geo.bg[i++]; 185 chan->freq = channel_frequencies[channel - 1]; 186 chan->channel = channel; 187 } 188 189 geo.bg_channels = i; 190 memcpy(geo.name, "XX ", 4); 191 ieee80211_set_geo(ieee, &geo); 192 return 0; 193} 194