xref: /linux/drivers/net/wireless/ath/ath9k/calib.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /*
2  * Copyright (c) 2008-2011 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 "hw.h"
18 #include "hw-ops.h"
19 #include <linux/export.h>
20 
21 /* Common calibration code */
22 
23 
24 static int16_t ath9k_hw_get_nf_hist_mid(int16_t *nfCalBuffer)
25 {
26 	int16_t nfval;
27 	int16_t sort[ATH9K_NF_CAL_HIST_MAX];
28 	int i, j;
29 
30 	for (i = 0; i < ATH9K_NF_CAL_HIST_MAX; i++)
31 		sort[i] = nfCalBuffer[i];
32 
33 	for (i = 0; i < ATH9K_NF_CAL_HIST_MAX - 1; i++) {
34 		for (j = 1; j < ATH9K_NF_CAL_HIST_MAX - i; j++) {
35 			if (sort[j] > sort[j - 1])
36 				swap(sort[j], sort[j - 1]);
37 		}
38 	}
39 	nfval = sort[(ATH9K_NF_CAL_HIST_MAX - 1) >> 1];
40 
41 	return nfval;
42 }
43 
44 static struct ath_nf_limits *ath9k_hw_get_nf_limits(struct ath_hw *ah,
45 						    struct ath9k_channel *chan)
46 {
47 	struct ath_nf_limits *limit;
48 
49 	if (!chan || IS_CHAN_2GHZ(chan))
50 		limit = &ah->nf_2g;
51 	else
52 		limit = &ah->nf_5g;
53 
54 	return limit;
55 }
56 
57 static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
58 				   struct ath9k_channel *chan,
59 				   int chain)
60 {
61 	s16 calib_nf = ath9k_hw_get_nf_limits(ah, chan)->cal[chain];
62 
63 	if (calib_nf)
64 		return calib_nf;
65 	else
66 		return ath9k_hw_get_nf_limits(ah, chan)->nominal;
67 }
68 
69 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan,
70 			   s16 nf)
71 {
72 	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
73 
74 	if (nf) {
75 		s8 delta = nf - ATH9K_NF_CAL_NOISE_THRESH -
76 			   ath9k_hw_get_default_nf(ah, chan, 0);
77 		if (delta > 0)
78 			noise += delta;
79 	}
80 	return noise;
81 }
82 EXPORT_SYMBOL(ath9k_hw_getchan_noise);
83 
84 static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
85 					      struct ath9k_hw_cal_data *cal,
86 					      int16_t *nfarray)
87 {
88 	struct ath_common *common = ath9k_hw_common(ah);
89 	struct ath_nf_limits *limit;
90 	struct ath9k_nfcal_hist *h;
91 	bool high_nf_mid = false;
92 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
93 	int i;
94 
95 	h = cal->nfCalHist;
96 	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
97 
98 	for (i = 0; i < NUM_NF_READINGS; i++) {
99 		if (!(chainmask & (1 << i)) ||
100 		    ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(ah->curchan)))
101 			continue;
102 
103 		h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
104 
105 		if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
106 			h[i].currIndex = 0;
107 
108 		if (h[i].invalidNFcount > 0) {
109 			h[i].invalidNFcount--;
110 			h[i].privNF = nfarray[i];
111 		} else {
112 			h[i].privNF =
113 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
114 		}
115 
116 		if (!h[i].privNF)
117 			continue;
118 
119 		if (h[i].privNF > limit->max) {
120 			high_nf_mid = true;
121 
122 			ath_dbg(common, CALIBRATE,
123 				"NFmid[%d] (%d) > MAX (%d), %s\n",
124 				i, h[i].privNF, limit->max,
125 				(test_bit(NFCAL_INTF, &cal->cal_flags) ?
126 				 "not corrected (due to interference)" :
127 				 "correcting to MAX"));
128 
129 			/*
130 			 * Normally we limit the average noise floor by the
131 			 * hardware specific maximum here. However if we have
132 			 * encountered stuck beacons because of interference,
133 			 * we bypass this limit here in order to better deal
134 			 * with our environment.
135 			 */
136 			if (!test_bit(NFCAL_INTF, &cal->cal_flags))
137 				h[i].privNF = limit->max;
138 		}
139 	}
140 
141 	/*
142 	 * If the noise floor seems normal for all chains, assume that
143 	 * there is no significant interference in the environment anymore.
144 	 * Re-enable the enforcement of the NF maximum again.
145 	 */
146 	if (!high_nf_mid)
147 		clear_bit(NFCAL_INTF, &cal->cal_flags);
148 }
149 
150 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
151 				   enum nl80211_band band,
152 				   int16_t *nft)
153 {
154 	switch (band) {
155 	case NL80211_BAND_5GHZ:
156 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
157 		break;
158 	case NL80211_BAND_2GHZ:
159 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
160 		break;
161 	default:
162 		BUG_ON(1);
163 		return false;
164 	}
165 
166 	return true;
167 }
168 
169 void ath9k_hw_reset_calibration(struct ath_hw *ah,
170 				struct ath9k_cal_list *currCal)
171 {
172 	int i;
173 
174 	ath9k_hw_setup_calibration(ah, currCal);
175 
176 	ah->cal_start_time = jiffies;
177 	currCal->calState = CAL_RUNNING;
178 
179 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
180 		ah->meas0.sign[i] = 0;
181 		ah->meas1.sign[i] = 0;
182 		ah->meas2.sign[i] = 0;
183 		ah->meas3.sign[i] = 0;
184 	}
185 
186 	ah->cal_samples = 0;
187 }
188 
189 /* This is done for the currently configured channel */
190 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
191 {
192 	struct ath_common *common = ath9k_hw_common(ah);
193 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
194 
195 	if (!ah->caldata)
196 		return true;
197 
198 	if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
199 		return true;
200 
201 	if (currCal == NULL)
202 		return true;
203 
204 	if (currCal->calState != CAL_DONE) {
205 		ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
206 			currCal->calState);
207 		return true;
208 	}
209 
210 	currCal = ah->cal_list;
211 	do {
212 		ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
213 			currCal->calData->calType,
214 			ah->curchan->chan->center_freq);
215 
216 		ah->caldata->CalValid &= ~currCal->calData->calType;
217 		currCal->calState = CAL_WAITING;
218 
219 		currCal = currCal->calNext;
220 	} while (currCal != ah->cal_list);
221 
222 	return false;
223 }
224 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
225 
226 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
227 {
228 	if (ah->caldata)
229 		set_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
230 
231 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
232 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
233 
234 	if (update)
235 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
236 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
237 	else
238 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
239 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
240 
241 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
242 }
243 
244 int ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
245 {
246 	struct ath9k_nfcal_hist *h = NULL;
247 	unsigned i, j;
248 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
249 	struct ath_common *common = ath9k_hw_common(ah);
250 	s16 default_nf = ath9k_hw_get_nf_limits(ah, chan)->nominal;
251 	u32 bb_agc_ctl = REG_READ(ah, AR_PHY_AGC_CONTROL(ah));
252 
253 	if (ah->caldata)
254 		h = ah->caldata->nfCalHist;
255 
256 	ENABLE_REG_RMW_BUFFER(ah);
257 	for (i = 0; i < NUM_NF_READINGS; i++) {
258 		if (chainmask & (1 << i)) {
259 			s16 nfval;
260 
261 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
262 				continue;
263 
264 			if (ah->nf_override)
265 				nfval = ah->nf_override;
266 			else if (h)
267 				nfval = h[i].privNF;
268 			else {
269 				/* Try to get calibrated noise floor value */
270 				nfval =
271 				    ath9k_hw_get_nf_limits(ah, chan)->cal[i];
272 				if (nfval > -60 || nfval < -127)
273 					nfval = default_nf;
274 			}
275 
276 			REG_RMW(ah, ah->nf_regs[i],
277 				(((u32) nfval << 1) & 0x1ff), 0x1ff);
278 		}
279 	}
280 
281 	/*
282 	 * stop NF cal if ongoing to ensure NF load completes immediately
283 	 * (or after end rx/tx frame if ongoing)
284 	 */
285 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
286 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
287 		REG_RMW_BUFFER_FLUSH(ah);
288 		ENABLE_REG_RMW_BUFFER(ah);
289 	}
290 
291 	/*
292 	 * Load software filtered NF value into baseband internal minCCApwr
293 	 * variable.
294 	 */
295 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
296 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
297 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
298 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
299 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
300 	REG_RMW_BUFFER_FLUSH(ah);
301 
302 	/*
303 	 * Wait for load to complete, should be fast, a few 10s of us.
304 	 * The max delay was changed from an original 250us to 22.2 msec.
305 	 * This would increase timeout to the longest possible frame
306 	 * (11n max length 22.1 msec)
307 	 */
308 	for (j = 0; j < 22200; j++) {
309 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) &
310 			      AR_PHY_AGC_CONTROL_NF) == 0)
311 			break;
312 		udelay(10);
313 	}
314 
315 	/*
316 	 * Restart NF so it can continue.
317 	 */
318 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
319 		ENABLE_REG_RMW_BUFFER(ah);
320 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_ENABLE_NF)
321 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
322 				    AR_PHY_AGC_CONTROL_ENABLE_NF);
323 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NO_UPDATE_NF)
324 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
325 				    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
326 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
327 		REG_RMW_BUFFER_FLUSH(ah);
328 	}
329 
330 	/*
331 	 * We timed out waiting for the noisefloor to load, probably due to an
332 	 * in-progress rx. Simply return here and allow the load plenty of time
333 	 * to complete before the next calibration interval.  We need to avoid
334 	 * trying to load -50 (which happens below) while the previous load is
335 	 * still in progress as this can cause rx deafness. Instead by returning
336 	 * here, the baseband nf cal will just be capped by our present
337 	 * noisefloor until the next calibration timer.
338 	 */
339 	if (j == 22200) {
340 		ath_dbg(common, ANY,
341 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
342 			REG_READ(ah, AR_PHY_AGC_CONTROL(ah)));
343 		return -ETIMEDOUT;
344 	}
345 
346 	/*
347 	 * Restore maxCCAPower register parameter again so that we're not capped
348 	 * by the median we just loaded.  This will be initial (and max) value
349 	 * of next noise floor calibration the baseband does.
350 	 */
351 	ENABLE_REG_RMW_BUFFER(ah);
352 	for (i = 0; i < NUM_NF_READINGS; i++) {
353 		if (chainmask & (1 << i)) {
354 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
355 				continue;
356 
357 			REG_RMW(ah, ah->nf_regs[i],
358 					(((u32) (-50) << 1) & 0x1ff), 0x1ff);
359 		}
360 	}
361 	REG_RMW_BUFFER_FLUSH(ah);
362 
363 	return 0;
364 }
365 EXPORT_SYMBOL(ath9k_hw_loadnf);
366 
367 
368 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
369 {
370 	struct ath_common *common = ath9k_hw_common(ah);
371 	struct ath_nf_limits *limit;
372 	int i;
373 
374 	if (IS_CHAN_2GHZ(ah->curchan))
375 		limit = &ah->nf_2g;
376 	else
377 		limit = &ah->nf_5g;
378 
379 	for (i = 0; i < NUM_NF_READINGS; i++) {
380 		if (!nf[i])
381 			continue;
382 
383 		ath_dbg(common, CALIBRATE,
384 			"NF calibrated [%s] [chain %d] is %d\n",
385 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
386 
387 		if (nf[i] > limit->max) {
388 			ath_dbg(common, CALIBRATE,
389 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
390 				i, nf[i], limit->max);
391 			nf[i] = limit->max;
392 		} else if (nf[i] < limit->min) {
393 			ath_dbg(common, CALIBRATE,
394 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
395 				i, nf[i], limit->min);
396 			nf[i] = limit->nominal;
397 		}
398 	}
399 }
400 
401 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
402 {
403 	struct ath_common *common = ath9k_hw_common(ah);
404 	int16_t nf, nfThresh;
405 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
406 	struct ath9k_nfcal_hist *h;
407 	struct ieee80211_channel *c = chan->chan;
408 	struct ath9k_hw_cal_data *caldata = ah->caldata;
409 
410 	if (REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF) {
411 		ath_dbg(common, CALIBRATE,
412 			"NF did not complete in calibration window\n");
413 		return false;
414 	}
415 
416 	ath9k_hw_do_getnf(ah, nfarray);
417 	ath9k_hw_nf_sanitize(ah, nfarray);
418 	nf = nfarray[0];
419 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
420 	    && nf > nfThresh) {
421 		ath_dbg(common, CALIBRATE,
422 			"noise floor failed detected; detected %d, threshold %d\n",
423 			nf, nfThresh);
424 	}
425 
426 	if (!caldata) {
427 		chan->noisefloor = nf;
428 		return false;
429 	}
430 
431 	h = caldata->nfCalHist;
432 	clear_bit(NFCAL_PENDING, &caldata->cal_flags);
433 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
434 	chan->noisefloor = h[0].privNF;
435 	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
436 	return true;
437 }
438 EXPORT_SYMBOL(ath9k_hw_getnf);
439 
440 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
441 				  struct ath9k_channel *chan)
442 {
443 	struct ath9k_nfcal_hist *h;
444 	int i, j, k = 0;
445 
446 	ah->caldata->channel = chan->channel;
447 	ah->caldata->channelFlags = chan->channelFlags;
448 	h = ah->caldata->nfCalHist;
449 	for (i = 0; i < NUM_NF_READINGS; i++) {
450 		h[i].currIndex = 0;
451 		h[i].privNF = ath9k_hw_get_default_nf(ah, chan, k);
452 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
453 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++)
454 			h[i].nfCalBuffer[j] = h[i].privNF;
455 		if (++k >= AR5416_MAX_CHAINS)
456 			k = 0;
457 	}
458 }
459 
460 
461 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
462 {
463 	struct ath9k_hw_cal_data *caldata = ah->caldata;
464 
465 	if (unlikely(!caldata))
466 		return;
467 
468 	/*
469 	 * If beacons are stuck, the most likely cause is interference.
470 	 * Triggering a noise floor calibration at this point helps the
471 	 * hardware adapt to a noisy environment much faster.
472 	 * To ensure that we recover from stuck beacons quickly, let
473 	 * the baseband update the internal NF value itself, similar to
474 	 * what is being done after a full reset.
475 	 */
476 	if (!test_bit(NFCAL_PENDING, &caldata->cal_flags))
477 		ath9k_hw_start_nfcal(ah, true);
478 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF))
479 		ath9k_hw_getnf(ah, ah->curchan);
480 
481 	set_bit(NFCAL_INTF, &caldata->cal_flags);
482 }
483 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
484 
485