xref: /openbmc/linux/drivers/net/wireless/ath/regd.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 <net/cfg80211.h>
19 #include <net/mac80211.h>
20 #include "regd.h"
21 #include "regd_common.h"
22 
23 /*
24  * This is a set of common rules used by our world regulatory domains.
25  * We have 12 world regulatory domains. To save space we consolidate
26  * the regulatory domains in 5 structures by frequency and change
27  * the flags on our reg_notifier() on a case by case basis.
28  */
29 
30 /* Only these channels all allow active scan on all world regulatory domains */
31 #define ATH9K_2GHZ_CH01_11	REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)
32 
33 /* We enable active scan on these a case by case basis by regulatory domain */
34 #define ATH9K_2GHZ_CH12_13	REG_RULE(2467-10, 2472+10, 40, 0, 20,\
35 					NL80211_RRF_PASSIVE_SCAN)
36 #define ATH9K_2GHZ_CH14		REG_RULE(2484-10, 2484+10, 40, 0, 20,\
37 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_OFDM)
38 
39 /* We allow IBSS on these on a case by case basis by regulatory domain */
40 #define ATH9K_5GHZ_5150_5350	REG_RULE(5150-10, 5350+10, 40, 0, 30,\
41 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
42 #define ATH9K_5GHZ_5470_5850	REG_RULE(5470-10, 5850+10, 40, 0, 30,\
43 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
44 #define ATH9K_5GHZ_5725_5850	REG_RULE(5725-10, 5850+10, 40, 0, 30,\
45 				NL80211_RRF_PASSIVE_SCAN | NL80211_RRF_NO_IBSS)
46 
47 #define ATH9K_2GHZ_ALL		ATH9K_2GHZ_CH01_11, \
48 				ATH9K_2GHZ_CH12_13, \
49 				ATH9K_2GHZ_CH14
50 
51 #define ATH9K_5GHZ_ALL		ATH9K_5GHZ_5150_5350, \
52 				ATH9K_5GHZ_5470_5850
53 
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 & COUNTRY_ERD_FLAG) != COUNTRY_ERD_FLAG) &&
114 		(((regd & WORLD_SKU_MASK) == WORLD_SKU_PREFIX) ||
115 		(regd == WORLD));
116 }
117 
118 static u16 ath_regd_get_eepromRD(struct ath_regulatory *reg)
119 {
120 	return reg->current_rd & ~WORLDWIDE_ROAMING_FLAG;
121 }
122 
123 bool ath_is_world_regd(struct ath_regulatory *reg)
124 {
125 	return is_wwr_sku(ath_regd_get_eepromRD(reg));
126 }
127 EXPORT_SYMBOL(ath_is_world_regd);
128 
129 static const struct ieee80211_regdomain *ath_default_world_regdomain(void)
130 {
131 	/* this is the most restrictive */
132 	return &ath_world_regdom_64;
133 }
134 
135 static const struct
136 ieee80211_regdomain *ath_world_regdomain(struct ath_regulatory *reg)
137 {
138 	switch (reg->regpair->regDmnEnum) {
139 	case 0x60:
140 	case 0x61:
141 	case 0x62:
142 		return &ath_world_regdom_60_61_62;
143 	case 0x63:
144 	case 0x65:
145 		return &ath_world_regdom_63_65;
146 	case 0x64:
147 		return &ath_world_regdom_64;
148 	case 0x66:
149 	case 0x69:
150 		return &ath_world_regdom_66_69;
151 	case 0x67:
152 	case 0x68:
153 	case 0x6A:
154 		return &ath_world_regdom_67_68_6A;
155 	default:
156 		WARN_ON(1);
157 		return ath_default_world_regdomain();
158 	}
159 }
160 
161 /* Frequency is one where radar detection is required */
162 static bool ath_is_radar_freq(u16 center_freq)
163 {
164 	return (center_freq >= 5260 && center_freq <= 5700);
165 }
166 
167 /*
168  * N.B: These exception rules do not apply radar freqs.
169  *
170  * - We enable adhoc (or beaconing) if allowed by 11d
171  * - We enable active scan if the channel is allowed by 11d
172  * - If no country IE has been processed and a we determine we have
173  *   received a beacon on a channel we can enable active scan and
174  *   adhoc (or beaconing).
175  */
176 static void
177 ath_reg_apply_beaconing_flags(struct wiphy *wiphy,
178 			      enum nl80211_reg_initiator initiator)
179 {
180 	enum ieee80211_band band;
181 	struct ieee80211_supported_band *sband;
182 	const struct ieee80211_reg_rule *reg_rule;
183 	struct ieee80211_channel *ch;
184 	unsigned int i;
185 	u32 bandwidth = 0;
186 	int r;
187 
188 	for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
189 
190 		if (!wiphy->bands[band])
191 			continue;
192 
193 		sband = wiphy->bands[band];
194 
195 		for (i = 0; i < sband->n_channels; i++) {
196 
197 			ch = &sband->channels[i];
198 
199 			if (ath_is_radar_freq(ch->center_freq) ||
200 			    (ch->flags & IEEE80211_CHAN_RADAR))
201 				continue;
202 
203 			if (initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
204 				r = freq_reg_info(wiphy,
205 						  ch->center_freq,
206 						  bandwidth,
207 						  &reg_rule);
208 				if (r)
209 					continue;
210 				/*
211 				 * If 11d had a rule for this channel ensure
212 				 * we enable adhoc/beaconing if it allows us to
213 				 * use it. Note that we would have disabled it
214 				 * by applying our static world regdomain by
215 				 * default during init, prior to calling our
216 				 * regulatory_hint().
217 				 */
218 				if (!(reg_rule->flags &
219 				    NL80211_RRF_NO_IBSS))
220 					ch->flags &=
221 					  ~IEEE80211_CHAN_NO_IBSS;
222 				if (!(reg_rule->flags &
223 				    NL80211_RRF_PASSIVE_SCAN))
224 					ch->flags &=
225 					  ~IEEE80211_CHAN_PASSIVE_SCAN;
226 			} else {
227 				if (ch->beacon_found)
228 					ch->flags &= ~(IEEE80211_CHAN_NO_IBSS |
229 					  IEEE80211_CHAN_PASSIVE_SCAN);
230 			}
231 		}
232 	}
233 
234 }
235 
236 /* Allows active scan scan on Ch 12 and 13 */
237 static void
238 ath_reg_apply_active_scan_flags(struct wiphy *wiphy,
239 				enum nl80211_reg_initiator initiator)
240 {
241 	struct ieee80211_supported_band *sband;
242 	struct ieee80211_channel *ch;
243 	const struct ieee80211_reg_rule *reg_rule;
244 	u32 bandwidth = 0;
245 	int r;
246 
247 	sband = wiphy->bands[IEEE80211_BAND_2GHZ];
248 
249 	/*
250 	 * If no country IE has been received always enable active scan
251 	 * on these channels. This is only done for specific regulatory SKUs
252 	 */
253 	if (initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
254 		ch = &sband->channels[11]; /* CH 12 */
255 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
256 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
257 		ch = &sband->channels[12]; /* CH 13 */
258 		if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
259 			ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
260 		return;
261 	}
262 
263 	/*
264 	 * If a country IE has been recieved check its rule for this
265 	 * channel first before enabling active scan. The passive scan
266 	 * would have been enforced by the initial processing of our
267 	 * custom regulatory domain.
268 	 */
269 
270 	ch = &sband->channels[11]; /* CH 12 */
271 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
272 	if (!r) {
273 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
274 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
275 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
276 	}
277 
278 	ch = &sband->channels[12]; /* CH 13 */
279 	r = freq_reg_info(wiphy, ch->center_freq, bandwidth, &reg_rule);
280 	if (!r) {
281 		if (!(reg_rule->flags & NL80211_RRF_PASSIVE_SCAN))
282 			if (ch->flags & IEEE80211_CHAN_PASSIVE_SCAN)
283 				ch->flags &= ~IEEE80211_CHAN_PASSIVE_SCAN;
284 	}
285 }
286 
287 /* Always apply Radar/DFS rules on freq range 5260 MHz - 5700 MHz */
288 static void ath_reg_apply_radar_flags(struct wiphy *wiphy)
289 {
290 	struct ieee80211_supported_band *sband;
291 	struct ieee80211_channel *ch;
292 	unsigned int i;
293 
294 	if (!wiphy->bands[IEEE80211_BAND_5GHZ])
295 		return;
296 
297 	sband = wiphy->bands[IEEE80211_BAND_5GHZ];
298 
299 	for (i = 0; i < sband->n_channels; i++) {
300 		ch = &sband->channels[i];
301 		if (!ath_is_radar_freq(ch->center_freq))
302 			continue;
303 		/* We always enable radar detection/DFS on this
304 		 * frequency range. Additionally we also apply on
305 		 * this frequency range:
306 		 * - If STA mode does not yet have DFS supports disable
307 		 *   active scanning
308 		 * - If adhoc mode does not support DFS yet then
309 		 *   disable adhoc in the frequency.
310 		 * - If AP mode does not yet support radar detection/DFS
311 		 *   do not allow AP mode
312 		 */
313 		if (!(ch->flags & IEEE80211_CHAN_DISABLED))
314 			ch->flags |= IEEE80211_CHAN_RADAR |
315 				     IEEE80211_CHAN_NO_IBSS |
316 				     IEEE80211_CHAN_PASSIVE_SCAN;
317 	}
318 }
319 
320 static void ath_reg_apply_world_flags(struct wiphy *wiphy,
321 				      enum nl80211_reg_initiator initiator,
322 				      struct ath_regulatory *reg)
323 {
324 	switch (reg->regpair->regDmnEnum) {
325 	case 0x60:
326 	case 0x63:
327 	case 0x66:
328 	case 0x67:
329 		ath_reg_apply_beaconing_flags(wiphy, initiator);
330 		break;
331 	case 0x68:
332 		ath_reg_apply_beaconing_flags(wiphy, initiator);
333 		ath_reg_apply_active_scan_flags(wiphy, initiator);
334 		break;
335 	}
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 	/*
346 	 * This would happen when we have sent a custom regulatory request
347 	 * a world regulatory domain and the scheduler hasn't yet processed
348 	 * any pending requests in the queue.
349 	 */
350 	if (!request)
351 		return 0;
352 
353 	switch (request->initiator) {
354 	case NL80211_REGDOM_SET_BY_DRIVER:
355 	case NL80211_REGDOM_SET_BY_CORE:
356 	case NL80211_REGDOM_SET_BY_USER:
357 		break;
358 	case NL80211_REGDOM_SET_BY_COUNTRY_IE:
359 		if (ath_is_world_regd(reg))
360 			ath_reg_apply_world_flags(wiphy, request->initiator,
361 						  reg);
362 		break;
363 	}
364 
365 	return 0;
366 }
367 EXPORT_SYMBOL(ath_reg_notifier_apply);
368 
369 static bool ath_regd_is_eeprom_valid(struct ath_regulatory *reg)
370 {
371 	u16 rd = ath_regd_get_eepromRD(reg);
372 	int i;
373 
374 	if (rd & COUNTRY_ERD_FLAG) {
375 		/* EEPROM value is a country code */
376 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
377 		printk(KERN_DEBUG
378 		       "ath: EEPROM indicates we should expect "
379 			"a country code\n");
380 		for (i = 0; i < ARRAY_SIZE(allCountries); i++)
381 			if (allCountries[i].countryCode == cc)
382 				return true;
383 	} else {
384 		/* EEPROM value is a regpair value */
385 		if (rd != CTRY_DEFAULT)
386 			printk(KERN_DEBUG "ath: EEPROM indicates we "
387 			       "should expect a direct regpair map\n");
388 		for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++)
389 			if (regDomainPairs[i].regDmnEnum == rd)
390 				return true;
391 	}
392 	printk(KERN_DEBUG
393 		 "ath: invalid regulatory domain/country code 0x%x\n", rd);
394 	return false;
395 }
396 
397 /* EEPROM country code to regpair mapping */
398 static struct country_code_to_enum_rd*
399 ath_regd_find_country(u16 countryCode)
400 {
401 	int i;
402 
403 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
404 		if (allCountries[i].countryCode == countryCode)
405 			return &allCountries[i];
406 	}
407 	return NULL;
408 }
409 
410 /* EEPROM rd code to regpair mapping */
411 static struct country_code_to_enum_rd*
412 ath_regd_find_country_by_rd(int regdmn)
413 {
414 	int i;
415 
416 	for (i = 0; i < ARRAY_SIZE(allCountries); i++) {
417 		if (allCountries[i].regDmnEnum == regdmn)
418 			return &allCountries[i];
419 	}
420 	return NULL;
421 }
422 
423 /* Returns the map of the EEPROM set RD to a country code */
424 static u16 ath_regd_get_default_country(u16 rd)
425 {
426 	if (rd & COUNTRY_ERD_FLAG) {
427 		struct country_code_to_enum_rd *country = NULL;
428 		u16 cc = rd & ~COUNTRY_ERD_FLAG;
429 
430 		country = ath_regd_find_country(cc);
431 		if (country != NULL)
432 			return cc;
433 	}
434 
435 	return CTRY_DEFAULT;
436 }
437 
438 static struct reg_dmn_pair_mapping*
439 ath_get_regpair(int regdmn)
440 {
441 	int i;
442 
443 	if (regdmn == NO_ENUMRD)
444 		return NULL;
445 	for (i = 0; i < ARRAY_SIZE(regDomainPairs); i++) {
446 		if (regDomainPairs[i].regDmnEnum == regdmn)
447 			return &regDomainPairs[i];
448 	}
449 	return NULL;
450 }
451 
452 static int
453 ath_regd_init_wiphy(struct ath_regulatory *reg,
454 		    struct wiphy *wiphy,
455 		    int (*reg_notifier)(struct wiphy *wiphy,
456 					struct regulatory_request *request))
457 {
458 	const struct ieee80211_regdomain *regd;
459 
460 	wiphy->reg_notifier = reg_notifier;
461 	wiphy->flags |= WIPHY_FLAG_STRICT_REGULATORY;
462 
463 	if (ath_is_world_regd(reg)) {
464 		/*
465 		 * Anything applied here (prior to wiphy registration) gets
466 		 * saved on the wiphy orig_* parameters
467 		 */
468 		regd = ath_world_regdomain(reg);
469 		wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY;
470 	} else {
471 		/*
472 		 * This gets applied in the case of the absense of CRDA,
473 		 * it's our own custom world regulatory domain, similar to
474 		 * cfg80211's but we enable passive scanning.
475 		 */
476 		regd = ath_default_world_regdomain();
477 	}
478 	wiphy_apply_custom_regulatory(wiphy, regd);
479 	ath_reg_apply_radar_flags(wiphy);
480 	ath_reg_apply_world_flags(wiphy, NL80211_REGDOM_SET_BY_DRIVER, reg);
481 	return 0;
482 }
483 
484 /*
485  * Some users have reported their EEPROM programmed with
486  * 0x8000 set, this is not a supported regulatory domain
487  * but since we have more than one user with it we need
488  * a solution for them. We default to 0x64, which is the
489  * default Atheros world regulatory domain.
490  */
491 static void ath_regd_sanitize(struct ath_regulatory *reg)
492 {
493 	if (reg->current_rd != COUNTRY_ERD_FLAG)
494 		return;
495 	printk(KERN_DEBUG "ath: EEPROM regdomain sanitized\n");
496 	reg->current_rd = 0x64;
497 }
498 
499 int
500 ath_regd_init(struct ath_regulatory *reg,
501 	      struct wiphy *wiphy,
502 	      int (*reg_notifier)(struct wiphy *wiphy,
503 				  struct regulatory_request *request))
504 {
505 	struct country_code_to_enum_rd *country = NULL;
506 	u16 regdmn;
507 
508 	if (!reg)
509 		return -EINVAL;
510 
511 	ath_regd_sanitize(reg);
512 
513 	printk(KERN_DEBUG "ath: EEPROM regdomain: 0x%0x\n", reg->current_rd);
514 
515 	if (!ath_regd_is_eeprom_valid(reg)) {
516 		printk(KERN_ERR "ath: Invalid EEPROM contents\n");
517 		return -EINVAL;
518 	}
519 
520 	regdmn = ath_regd_get_eepromRD(reg);
521 	reg->country_code = ath_regd_get_default_country(regdmn);
522 
523 	if (reg->country_code == CTRY_DEFAULT &&
524 	    regdmn == CTRY_DEFAULT) {
525 		printk(KERN_DEBUG "ath: EEPROM indicates default "
526 		       "country code should be used\n");
527 		reg->country_code = CTRY_UNITED_STATES;
528 	}
529 
530 	if (reg->country_code == CTRY_DEFAULT) {
531 		country = NULL;
532 	} else {
533 		printk(KERN_DEBUG "ath: doing EEPROM country->regdmn "
534 		       "map search\n");
535 		country = ath_regd_find_country(reg->country_code);
536 		if (country == NULL) {
537 			printk(KERN_DEBUG
538 				"ath: no valid country maps found for "
539 				"country code: 0x%0x\n",
540 				reg->country_code);
541 			return -EINVAL;
542 		} else {
543 			regdmn = country->regDmnEnum;
544 			printk(KERN_DEBUG "ath: country maps to "
545 			       "regdmn code: 0x%0x\n",
546 			       regdmn);
547 		}
548 	}
549 
550 	reg->regpair = ath_get_regpair(regdmn);
551 
552 	if (!reg->regpair) {
553 		printk(KERN_DEBUG "ath: "
554 			"No regulatory domain pair found, cannot continue\n");
555 		return -EINVAL;
556 	}
557 
558 	if (!country)
559 		country = ath_regd_find_country_by_rd(regdmn);
560 
561 	if (country) {
562 		reg->alpha2[0] = country->isoName[0];
563 		reg->alpha2[1] = country->isoName[1];
564 	} else {
565 		reg->alpha2[0] = '0';
566 		reg->alpha2[1] = '0';
567 	}
568 
569 	printk(KERN_DEBUG "ath: Country alpha2 being used: %c%c\n",
570 		reg->alpha2[0], reg->alpha2[1]);
571 	printk(KERN_DEBUG "ath: Regpair used: 0x%0x\n",
572 		reg->regpair->regDmnEnum);
573 
574 	ath_regd_init_wiphy(reg, wiphy, reg_notifier);
575 	return 0;
576 }
577 EXPORT_SYMBOL(ath_regd_init);
578 
579 u32 ath_regd_get_band_ctl(struct ath_regulatory *reg,
580 			  enum ieee80211_band band)
581 {
582 	if (!reg->regpair ||
583 	    (reg->country_code == CTRY_DEFAULT &&
584 	     is_wwr_sku(ath_regd_get_eepromRD(reg)))) {
585 		return SD_NO_CTL;
586 	}
587 
588 	switch (band) {
589 	case IEEE80211_BAND_2GHZ:
590 		return reg->regpair->reg_2ghz_ctl;
591 	case IEEE80211_BAND_5GHZ:
592 		return reg->regpair->reg_5ghz_ctl;
593 	default:
594 		return NO_CTL;
595 	}
596 }
597 EXPORT_SYMBOL(ath_regd_get_band_ctl);
598