blob: 185488da246647c06bd85261f856a71fed182c34 [file] [log] [blame]
Johannes Berg8318d782008-01-24 19:38:38 +01001/*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
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 version 2 as
8 * published by the Free Software Foundation.
9 */
10
11/*
12 * This regulatory domain control implementation is highly incomplete, it
13 * only exists for the purpose of not regressing mac80211.
14 *
15 * For now, drivers can restrict the set of allowed channels by either
16 * not registering those channels or setting the IEEE80211_CHAN_DISABLED
17 * flag; that flag will only be *set* by this code, never *cleared.
18 *
19 * The usual implementation is for a driver to read a device EEPROM to
20 * determine which regulatory domain it should be operating under, then
21 * looking up the allowable channels in a driver-local table and finally
22 * registering those channels in the wiphy structure.
23 *
24 * Alternatively, drivers that trust the regulatory domain control here
25 * will register a complete set of capabilities and the control code
26 * will restrict the set by setting the IEEE80211_CHAN_* flags.
27 */
28#include <linux/kernel.h>
29#include <net/wireless.h>
30#include "core.h"
31
32static char *ieee80211_regdom = "US";
33module_param(ieee80211_regdom, charp, 0444);
34MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
35
36struct ieee80211_channel_range {
37 short start_freq;
38 short end_freq;
39 int max_power;
40 int max_antenna_gain;
41 u32 flags;
42};
43
44struct ieee80211_regdomain {
45 const char *code;
46 const struct ieee80211_channel_range *ranges;
47 int n_ranges;
48};
49
50#define RANGE_PWR(_start, _end, _pwr, _ag, _flags) \
51 { _start, _end, _pwr, _ag, _flags }
52
53
54/*
55 * Ideally, in the future, these definitions will be loaded from a
56 * userspace table via some daemon.
57 */
58static const struct ieee80211_channel_range ieee80211_US_channels[] = {
59 /* IEEE 802.11b/g, channels 1..11 */
60 RANGE_PWR(2412, 2462, 27, 6, 0),
Tomas Winklerb46b4ee2008-02-13 20:58:34 +020061 /* IEEE 802.11a, channel 36*/
62 RANGE_PWR(5180, 5180, 23, 6, 0),
63 /* IEEE 802.11a, channel 40*/
64 RANGE_PWR(5200, 5200, 23, 6, 0),
65 /* IEEE 802.11a, channel 44*/
66 RANGE_PWR(5220, 5220, 23, 6, 0),
67 /* IEEE 802.11a, channels 48..64 */
68 RANGE_PWR(5240, 5320, 23, 6, 0),
Johannes Berg8318d782008-01-24 19:38:38 +010069 /* IEEE 802.11a, channels 149..165, outdoor */
70 RANGE_PWR(5745, 5825, 30, 6, 0),
71};
72
73static const struct ieee80211_channel_range ieee80211_JP_channels[] = {
74 /* IEEE 802.11b/g, channels 1..14 */
75 RANGE_PWR(2412, 2484, 20, 6, 0),
76 /* IEEE 802.11a, channels 34..48 */
77 RANGE_PWR(5170, 5240, 20, 6, IEEE80211_CHAN_PASSIVE_SCAN),
78 /* IEEE 802.11a, channels 52..64 */
79 RANGE_PWR(5260, 5320, 20, 6, IEEE80211_CHAN_NO_IBSS |
80 IEEE80211_CHAN_RADAR),
81};
82
83#define REGDOM(_code) \
84 { \
85 .code = __stringify(_code), \
86 .ranges = ieee80211_ ##_code## _channels, \
87 .n_ranges = ARRAY_SIZE(ieee80211_ ##_code## _channels), \
88 }
89
90static const struct ieee80211_regdomain ieee80211_regdoms[] = {
91 REGDOM(US),
92 REGDOM(JP),
93};
94
95
96static const struct ieee80211_regdomain *get_regdom(void)
97{
98 static const struct ieee80211_channel_range
99 ieee80211_world_channels[] = {
100 /* IEEE 802.11b/g, channels 1..11 */
101 RANGE_PWR(2412, 2462, 27, 6, 0),
102 };
103 static const struct ieee80211_regdomain regdom_world = REGDOM(world);
104 int i;
105
106 for (i = 0; i < ARRAY_SIZE(ieee80211_regdoms); i++)
107 if (strcmp(ieee80211_regdom, ieee80211_regdoms[i].code) == 0)
108 return &ieee80211_regdoms[i];
109
110 return &regdom_world;
111}
112
113
114static void handle_channel(struct ieee80211_channel *chan,
115 const struct ieee80211_regdomain *rd)
116{
117 int i;
118 u32 flags = chan->orig_flags;
119 const struct ieee80211_channel_range *rg = NULL;
120
121 for (i = 0; i < rd->n_ranges; i++) {
122 if (rd->ranges[i].start_freq <= chan->center_freq &&
123 chan->center_freq <= rd->ranges[i].end_freq) {
124 rg = &rd->ranges[i];
125 break;
126 }
127 }
128
129 if (!rg) {
130 /* not found */
131 flags |= IEEE80211_CHAN_DISABLED;
132 chan->flags = flags;
133 return;
134 }
135
136 chan->flags = flags;
137 chan->max_antenna_gain = min(chan->orig_mag,
138 rg->max_antenna_gain);
John W. Linville253898c2008-04-03 15:32:54 -0400139 if (chan->orig_mpwr)
140 chan->max_power = min(chan->orig_mpwr, rg->max_power);
141 else
142 chan->max_power = rg->max_power;
Johannes Berg8318d782008-01-24 19:38:38 +0100143}
144
145static void handle_band(struct ieee80211_supported_band *sband,
146 const struct ieee80211_regdomain *rd)
147{
148 int i;
149
150 for (i = 0; i < sband->n_channels; i++)
151 handle_channel(&sband->channels[i], rd);
152}
153
154void wiphy_update_regulatory(struct wiphy *wiphy)
155{
156 enum ieee80211_band band;
157 const struct ieee80211_regdomain *rd = get_regdom();
158
159 for (band = 0; band < IEEE80211_NUM_BANDS; band++)
160 if (wiphy->bands[band])
161 handle_band(wiphy->bands[band], rd);
162}