xref: /openbmc/linux/drivers/net/wireless/ath/regd.c (revision e8e0929d)
1 /*
2  * Copyright (c) 2008-2009 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/slab.h>
19 #include <net/cfg80211.h>
20 #include <net/mac80211.h>
21 #include "regd.h"
22 #include "regd_common.h"
23 
24 /*
25  * This is a set of common rules used by our world regulatory domains.
26  * We have 12 world regulatory domains. To save space we consolidate
27  * the regulatory domains in 5 structures by frequency and change
28  * the flags on our reg_notifier() on a case by case basis.
29  */
30 
31 /* Only these channels all allow active scan on all world regulatory domains */
32 #define ATH9K_2GHZ_CH01_11	REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)
33 
34 /* We enable active scan on these a case by case basis by regulatory domain */
35 #define ATH9K_2GHZ_CH12_13	REG_RULE(2467-10, 2472+10, 40, 0, 20,\
36 					NL80211_RRF_PASSIVE_SCAN)
37 #define ATH9K_2GHZ_CH14		REG_RULE(2484-10, 2484+10, 40, 0, 20,\
38 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)
39 
40 /* We allow IBSS on these on a case by case basis by regulatory domain */
41 #define ATH9K_5GHZ_5150_5350	REG_RULE(5150-10, 5350+10, 40, 0, 30,\
42 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
43 #define ATH9K_5GHZ_5470_5850	REG_RULE(5470-10, 5850+10, 40, 0, 30,\
44 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
45 #define ATH9K_5GHZ_5725_5850	REG_RULE(5725-10, 5850+10, 40, 0, 30,\
46 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
47 
48 #define ATH9K_2GHZ_ALL		ATH9K_2GHZ_CH01_11, \
49 				ATH9K_2GHZ_CH12_13, \
50 				ATH9K_2GHZ_CH14
51 
52 #define ATH9K_5GHZ_ALL		ATH9K_5GHZ_5150_5350, \
53 				ATH9K_5GHZ_5470_5850
54 /* This one skips what we call "mid band" */
55 #define ATH9K_5GHZ_NO_MIDBAND	ATH9K_5GHZ_5150_5350, \
56 				ATH9K_5GHZ_5725_5850
57 
58 /* Can be used for:
59  * 0x60, 0x61, 0x62 */
60 static const struct ieee80211_regdomain ath_world_regdom_60_61_62 = {
61 	.n_reg_rules = 5,
62 	.alpha2 =  "99",
63 	.reg_rules = {
64 		ATH9K_2GHZ_ALL,
65 		ATH9K_5GHZ_ALL,
66 	}
67 };
68 
69 /* Can be used by 0x63 and 0x65 */
70 static const struct ieee80211_regdomain ath_world_regdom_63_65 = {
71 	.n_reg_rules = 4,
72 	.alpha2 =  "99",
73 	.reg_rules = {
74 		ATH9K_2GHZ_CH01_11,
75 		ATH9K_2GHZ_CH12_13,
76 		ATH9K_5GHZ_NO_MIDBAND,
77 	}
78 };
79 
80 /* Can be used by 0x64 only */
81 static const struct ieee80211_regdomain ath_world_regdom_64 = {
82 	.n_reg_rules = 3,
83 	.alpha2 =  "99",
84 	.reg_rules = {
85 		ATH9K_2GHZ_CH01_11,
86 		ATH9K_5GHZ_NO_MIDBAND,
87 	}
88 };
89 
90 /* Can be used by 0x66 and 0x69 */
91 static const struct ieee80211_regdomain ath_world_regdom_66_69 = {
92 	.n_reg_rules = 3,
93 	.alpha2 =  "99",
94 	.reg_rules = {
95 		ATH9K_2GHZ_CH01_11,
96 		ATH9K_5GHZ_ALL,
97 	}
98 };
99 
100 /* Can be used by 0x67, 0x6A and 0x68 */
101 static const struct ieee80211_regdomain ath_world_regdom_67_68_6A = {
102 	.n_reg_rules = 4,
103 	.alpha2 =  "99",
104 	.reg_rules = {
105 		ATH9K_2GHZ_CH01_11,
106 		ATH9K_2GHZ_CH12_13,
107 		ATH9K_5GHZ_ALL,
108 	}
109 };
110 
111 static inline bool is_wwr_sku(u16 regd)
112 {
113 	return ((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
114 		(regd == WORLD);
115 }
116 
117 static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
118 {
119 	return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
120 }
121 
122 bool ath_is_world_regd(struct ath_regulatory *reg)
123 {
124 	return is_wwr_sku(ath_regd_get_eepromRD(reg));
125 }
126 EXPORT_SYMBOL(ath_is_world_regd);
127 
128 static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
129 {
130 	/* this is the most restrictive */
131 	return &ath_world_regdom_64;
132 }
133 
134 static const struct
135 ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
136 {
137 	switch (reg->regpair->regDmnEnum) {
138 	case 0x60:
139 	case 0x61:
140 	case 0x62:
141 		return &ath_world_regdom_60_61_62;
142 	case 0x63:
143 	case 0x65:
144 		return &ath_world_regdom_63_65;
145 	case 0x64:
146 		return &ath_world_regdom_64;
147 	case 0x66:
148 	case 0x69:
149 		return &ath_world_regdom_66_69;
150 	case 0x67:
151 	case 0x68:
152 	case 0x6A:
153 		return &ath_world_regdom_67_68_6A;
154 	default:
155 		WARN_ON(1);
156 		return ath_default_world_regdomain();
157 	}
158 }
159 
160 /* Frequency is one where radar detection is required */
161 static bool ath_is_radar_freq(u16 center_freq)
162 {
163 	return (center_freq >= 5260 && center_freq <= 5700);
164 }
165 
166 /*
167  * N.B: These exception rules do not apply radar freqs.
168  *
169  * - We enable adhoc (or beaconing) if allowed by 11d
170  * - We enable active scan if the channel is allowed by 11d
171  * - If no country IE has been processed and a we determine we have
172  *   received a beacon on a channel we can enable active scan and
173  *   adhoc (or beaconing).
174  */
175 static void
176 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
177 			      enum nl80211_reg_initiator initiator)
178 {
179 	enum ieee80211_band band;
180 	struct ieee80211_supported_band *sband;
181 	const struct ieee80211_reg_rule *reg_rule;
182 	struct ieee80211_channel *ch;
183 	unsigned int i;
184 	u32 bandwidth = 0;
185 	int r;
186 
187 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
188 
189 		if (!wiphy->bands[band])
190 			continue;
191 
192 		sband = wiphy->bands[band];
193 
194 		for (i = 0; i < sband->n_channels; i++) {
195 
196 			ch = &sband->channels[i];
197 
198 			if (ath_is_radar_freq(ch->center_freq) ||
199 			    (ch->flags & IEEE80211_CHAN_RADAR))
200 				continue;
201 
202 			if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
203 				r = freq_reg_info(wiphy,
204 						  ch->center_freq,
205 						  bandwidth,
206 						  &reg_rule);
207 				if (r)
208 					continue;
209 				/*
210 				 * If 11d had a rule for this channel ensure
211 				 * we enable adhoc/beaconing if it allows us to
212 				 * use it. Note that we would have disabled it
213 				 * by applying our static world regdomain by
214 				 * default during init, prior to calling our
215 				 * regulatory_hint().
216 				 */
217 				if (!(reg_rule->flags &
218 				    NL80211_RRF_NO_IBSS))
219 					ch->flags &=
220 					  ~IEEE80211_CHAN_NO_IBSS;
221 				if (!(reg_rule->flags &
222 				    NL80211_RRF_PASSIVE_SCAN))
223 					ch->flags &=
224 					  ~IEEE80211_CHAN_PASSIVE_SCAN;
225 			} else {
226 				if (ch->beacon_found)
227 					ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
228 					  IEEE80211_CHAN_PASSIVE_SCAN);
229 			}
230 		}
231 	}
232 
233 }
234 
235 /* Allows active scan scan on Ch 12 and 13 */
236 static void
237 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
238 				enum nl80211_reg_initiator initiator)
239 {
240 	struct ieee80211_supported_band *sband;
241 	struct ieee80211_channel *ch;
242 	const struct ieee80211_reg_rule *reg_rule;
243 	u32 bandwidth = 0;
244 	int r;
245 
246 	sband = wiphy->bands[IEEE80211_BAND_2GHZ];
247 
248 	/*
249 	 * If no country IE has been received always enable active scan
250 	 * on these channels. This is only done for specific regulatory SKUs
251 	 */
252 	if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
253 		ch = &sband->channels[11]; /* CH 12 */
254 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
255 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
256 		ch = &sband->channels[12]; /* CH 13 */
257 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
258 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
259 		return;
260 	}
261 
262 	/*
263 	 * If a country IE has been recieved check its rule for this
264 	 * channel first before enabling active scan. The passive scan
265 	 * would have been enforced by the initial processing of our
266 	 * custom regulatory domain.
267 	 */
268 
269 	ch = &sband->channels[11]; /* CH 12 */
270 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
271 	if (!r) {
272 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
273 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
274 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
275 	}
276 
277 	ch = &sband->channels[12]; /* CH 13 */
278 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
279 	if (!r) {
280 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
281 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
282 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
283 	}
284 }
285 
286 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
287 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
288 {
289 	struct ieee80211_supported_band *sband;
290 	struct ieee80211_channel *ch;
291 	unsigned int i;
292 
293 	if (!wiphy->bands[IEEE80211_BAND_5GHZ])
294 		return;
295 
296 	sband = wiphy->bands[IEEE80211_BAND_5GHZ];
297 
298 	for (i = 0; i < sband->n_channels; i++) {
299 		ch = &sband->channels[i];
300 		if (!ath_is_radar_freq(ch->center_freq))
301 			continue;
302 		/* We always enable radar detection/DFS on this
303 		 * frequency range. Additionally we also apply on
304 		 * this frequency range:
305 		 * - If STA mode does not yet have DFS supports disable
306 		 *   active scanning
307 		 * - If adhoc mode does not support DFS yet then
308 		 *   disable adhoc in the frequency.
309 		 * - If AP mode does not yet support radar detection/DFS
310 		 *   do not allow AP mode
311 		 */
312 		if (!(ch->flags & IEEE80211_CHAN_DISABLED))
313 			ch->flags |= IEEE80211_CHAN_RADAR |
314 				     IEEE80211_CHAN_NO_IBSS |
315 				     IEEE80211_CHAN_PASSIVE_SCAN;
316 	}
317 }
318 
319 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
320 				      enum nl80211_reg_initiator initiator,
321 				      struct ath_regulatory *reg)
322 {
323 	switch (reg->regpair->regDmnEnum) {
324 	case 0x60:
325 	case 0x63:
326 	case 0x66:
327 	case 0x67:
328 		ath_reg_apply_beaconing_flags(wiphy, initiator);
329 		break;
330 	case 0x68:
331 		ath_reg_apply_beaconing_flags(wiphy, initiator);
332 		ath_reg_apply_active_scan_flags(wiphy, initiator);
333 		break;
334 	}
335 	return;
336 }
337 
338 int ath_reg_notifier_apply(struct wiphy *wiphy,
339 			   struct regulatory_request *request,
340 			   struct ath_regulatory *reg)
341 {
342 	/* We always apply this */
343 	ath_reg_apply_radar_flags(wiphy);
344 
345 	switch (request->initiator) {
346 	case NL80211_REGDOM_SET_BY_DRIVER:
347 	case NL80211_REGDOM_SET_BY_CORE:
348 	case NL80211_REGDOM_SET_BY_USER:
349 		break;
350 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
351 		if (ath_is_world_regd(reg))
352 			ath_reg_apply_world_flags(wiphy, request->initiator,
353 						  reg);
354 		break;
355 	}
356 
357 	return 0;
358 }
359 EXPORT_SYMBOL(ath_reg_notifier_apply);
360 
361 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
362 {
363 	 u16 rd = ath_regd_get_eepromRD(reg);
364 	int i;
365 
366 	if (rd & COUNTRY_ERD_FLAG) {
367 		/* EEPROM value is a country code */
368 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
369 		printk(KERN_DEBUG
370 		       "ath: EEPROM indicates we should expect "
371 			"a country code\n");
372 		for (i = 0; i < ARRAY_SIZE(allCountries); i++)
373 			if (allCountries[i].countryCode == cc)
374 				return true;
375 	} else {
376 		/* EEPROM value is a regpair value */
377 		if (rd != CTRY_DEFAULT)
378 			printk(KERN_DEBUG "ath: EEPROM indicates we "
379 			       "should expect a direct regpair map\n");
380 		for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
381 			if (regDomainPairs[i].regDmnEnum == rd)
382 				return true;
383 	}
384 	printk(KERN_DEBUG
385 		 "ath: invalid regulatory domain/country code 0x%x\n", rd);
386 	return false;
387 }
388 
389 /* EEPROM country code to regpair mapping */
390 static struct country_code_to_enum_rd*
391 ath_regd_find_country(u16 countryCode)
392 {
393 	int i;
394 
395 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
396 		if (allCountries[i].countryCode == countryCode)
397 			return &allCountries[i];
398 	}
399 	return NULL;
400 }
401 
402 /* EEPROM rd code to regpair mapping */
403 static struct country_code_to_enum_rd*
404 ath_regd_find_country_by_rd(int regdmn)
405 {
406 	int i;
407 
408 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
409 		if (allCountries[i].regDmnEnum == regdmn)
410 			return &allCountries[i];
411 	}
412 	return NULL;
413 }
414 
415 /* Returns the map of the EEPROM set RD to a country code */
416 static u16 ath_regd_get_default_country(u16 rd)
417 {
418 	if (rd & COUNTRY_ERD_FLAG) {
419 		struct country_code_to_enum_rd *country = NULL;
420 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
421 
422 		country = ath_regd_find_country(cc);
423 		if (country != NULL)
424 			return cc;
425 	}
426 
427 	return CTRY_DEFAULT;
428 }
429 
430 static struct reg_dmn_pair_mapping*
431 ath_get_regpair(int regdmn)
432 {
433 	int i;
434 
435 	if (regdmn == NO_ENUMRD)
436 		return NULL;
437 	for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
438 		if (regDomainPairs[i].regDmnEnum == regdmn)
439 			return &regDomainPairs[i];
440 	}
441 	return NULL;
442 }
443 
444 static int
445 ath_regd_init_wiphy(struct ath_regulatory *reg,
446 		    struct wiphy *wiphy,
447 		    int (*reg_notifier)(struct wiphy *wiphy,
448 					struct regulatory_request *request))
449 {
450 	const struct ieee80211_regdomain *regd;
451 
452 	wiphy->reg_notifier = reg_notifier;
453 	wiphy->strict_regulatory = true;
454 
455 	if (ath_is_world_regd(reg)) {
456 		/*
457 		 * Anything applied here (prior to wiphy registration) gets
458 		 * saved on the wiphy orig_* parameters
459 		 */
460 		regd = ath_world_regdomain(reg);
461 		wiphy->custom_regulatory = true;
462 		wiphy->strict_regulatory = false;
463 	} else {
464 		/*
465 		 * This gets applied in the case of the absense of CRDA,
466 		 * it's our own custom world regulatory domain, similar to
467 		 * cfg80211's but we enable passive scanning.
468 		 */
469 		regd = ath_default_world_regdomain();
470 	}
471 	wiphy_apply_custom_regulatory(wiphy, regd);
472 	ath_reg_apply_radar_flags(wiphy);
473 	ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
474 	return 0;
475 }
476 
477 /*
478  * Some users have reported their EEPROM programmed with
479  * 0x8000 set, this is not a supported regulatory domain
480  * but since we have more than one user with it we need
481  * a solution for them. We default to 0x64, which is the
482  * default Atheros world regulatory domain.
483  */
484 static void ath_regd_sanitize(struct ath_regulatory *reg)
485 {
486 	if (reg->current_rd != COUNTRY_ERD_FLAG)
487 		return;
488 	printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
489 	reg->current_rd = 0x64;
490 }
491 
492 int
493 ath_regd_init(struct ath_regulatory *reg,
494 	      struct wiphy *wiphy,
495 	      int (*reg_notifier)(struct wiphy *wiphy,
496 				  struct regulatory_request *request))
497 {
498 	struct country_code_to_enum_rd *country = NULL;
499 	u16 regdmn;
500 
501 	if (!reg)
502 		return -EINVAL;
503 
504 	ath_regd_sanitize(reg);
505 
506 	printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
507 
508 	if (!ath_regd_is_eeprom_valid(reg)) {
509 		printk(KERN_ERR "ath: Invalid EEPROM contents\n");
510 		return -EINVAL;
511 	}
512 
513 	regdmn = ath_regd_get_eepromRD(reg);
514 	reg->country_code = ath_regd_get_default_country(regdmn);
515 
516 	if (reg->country_code == CTRY_DEFAULT &&
517 	    regdmn == CTRY_DEFAULT) {
518 		printk(KERN_DEBUG "ath: EEPROM indicates default "
519 		       "country code should be used\n");
520 		reg->country_code = CTRY_UNITED_STATES;
521 	}
522 
523 	if (reg->country_code == CTRY_DEFAULT) {
524 		country = NULL;
525 	} else {
526 		printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
527 		       "map search\n");
528 		country = ath_regd_find_country(reg->country_code);
529 		if (country == NULL) {
530 			printk(KERN_DEBUG
531 				"ath: no valid country maps found for "
532 				"country code: 0x%0x\n",
533 				reg->country_code);
534 			return -EINVAL;
535 		} else {
536 			regdmn = country->regDmnEnum;
537 			printk(KERN_DEBUG "ath: country maps to "
538 			       "regdmn code: 0x%0x\n",
539 			       regdmn);
540 		}
541 	}
542 
543 	reg->regpair = ath_get_regpair(regdmn);
544 
545 	if (!reg->regpair) {
546 		printk(KERN_DEBUG "ath: "
547 			"No regulatory domain pair found, cannot continue\n");
548 		return -EINVAL;
549 	}
550 
551 	if (!country)
552 		country = ath_regd_find_country_by_rd(regdmn);
553 
554 	if (country) {
555 		reg->alpha2[0] = country->isoName[0];
556 		reg->alpha2[1] = country->isoName[1];
557 	} else {
558 		reg->alpha2[0] = '0';
559 		reg->alpha2[1] = '0';
560 	}
561 
562 	printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
563 		reg->alpha2[0], reg->alpha2[1]);
564 	printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
565 		reg->regpair->regDmnEnum);
566 
567 	ath_regd_init_wiphy(reg, wiphy, reg_notifier);
568 	return 0;
569 }
570 EXPORT_SYMBOL(ath_regd_init);
571 
572 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
573 			  enum ieee80211_band band)
574 {
575 	if (!reg->regpair ||
576 	    (reg->country_code == CTRY_DEFAULT &&
577 	     is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
578 		return SD_NO_CTL;
579 	}
580 
581 	switch (band) {
582 	case IEEE80211_BAND_2GHZ:
583 		return reg->regpair->reg_2ghz_ctl;
584 	case IEEE80211_BAND_5GHZ:
585 		return reg->regpair->reg_5ghz_ctl;
586 	default:
587 		return NO_CTL;
588 	}
589 }
590 EXPORT_SYMBOL(ath_regd_get_band_ctl);
591