xref: /linux/drivers/net/wireless/ath/ath9k/calib.c (revision 0e9b70c1e3623fa110fb6be553e644524228ef60)
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 				nfval = sort[j];
37 				sort[j] = sort[j - 1];
38 				sort[j - 1] = nfval;
39 			}
40 		}
41 	}
42 	nfval = sort[(ATH9K_NF_CAL_HIST_MAX - 1) >> 1];
43 
44 	return nfval;
45 }
46 
47 static struct ath_nf_limits *ath9k_hw_get_nf_limits(struct ath_hw *ah,
48 						    struct ath9k_channel *chan)
49 {
50 	struct ath_nf_limits *limit;
51 
52 	if (!chan || IS_CHAN_2GHZ(chan))
53 		limit = &ah->nf_2g;
54 	else
55 		limit = &ah->nf_5g;
56 
57 	return limit;
58 }
59 
60 static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
61 				   struct ath9k_channel *chan,
62 				   int chain)
63 {
64 	s16 calib_nf = ath9k_hw_get_nf_limits(ah, chan)->cal[chain];
65 
66 	if (calib_nf)
67 		return calib_nf;
68 	else
69 		return ath9k_hw_get_nf_limits(ah, chan)->nominal;
70 }
71 
72 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan,
73 			   s16 nf)
74 {
75 	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
76 
77 	if (nf) {
78 		s8 delta = nf - ATH9K_NF_CAL_NOISE_THRESH -
79 			   ath9k_hw_get_default_nf(ah, chan, 0);
80 		if (delta > 0)
81 			noise += delta;
82 	}
83 	return noise;
84 }
85 EXPORT_SYMBOL(ath9k_hw_getchan_noise);
86 
87 static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
88 					      struct ath9k_hw_cal_data *cal,
89 					      int16_t *nfarray)
90 {
91 	struct ath_common *common = ath9k_hw_common(ah);
92 	struct ath_nf_limits *limit;
93 	struct ath9k_nfcal_hist *h;
94 	bool high_nf_mid = false;
95 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
96 	int i;
97 
98 	h = cal->nfCalHist;
99 	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
100 
101 	for (i = 0; i < NUM_NF_READINGS; i++) {
102 		if (!(chainmask & (1 << i)) ||
103 		    ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(ah->curchan)))
104 			continue;
105 
106 		h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
107 
108 		if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
109 			h[i].currIndex = 0;
110 
111 		if (h[i].invalidNFcount > 0) {
112 			h[i].invalidNFcount--;
113 			h[i].privNF = nfarray[i];
114 		} else {
115 			h[i].privNF =
116 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
117 		}
118 
119 		if (!h[i].privNF)
120 			continue;
121 
122 		if (h[i].privNF > limit->max) {
123 			high_nf_mid = true;
124 
125 			ath_dbg(common, CALIBRATE,
126 				"NFmid[%d] (%d) > MAX (%d), %s\n",
127 				i, h[i].privNF, limit->max,
128 				(test_bit(NFCAL_INTF, &cal->cal_flags) ?
129 				 "not corrected (due to interference)" :
130 				 "correcting to MAX"));
131 
132 			/*
133 			 * Normally we limit the average noise floor by the
134 			 * hardware specific maximum here. However if we have
135 			 * encountered stuck beacons because of interference,
136 			 * we bypass this limit here in order to better deal
137 			 * with our environment.
138 			 */
139 			if (!test_bit(NFCAL_INTF, &cal->cal_flags))
140 				h[i].privNF = limit->max;
141 		}
142 	}
143 
144 	/*
145 	 * If the noise floor seems normal for all chains, assume that
146 	 * there is no significant interference in the environment anymore.
147 	 * Re-enable the enforcement of the NF maximum again.
148 	 */
149 	if (!high_nf_mid)
150 		clear_bit(NFCAL_INTF, &cal->cal_flags);
151 }
152 
153 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
154 				   enum nl80211_band band,
155 				   int16_t *nft)
156 {
157 	switch (band) {
158 	case NL80211_BAND_5GHZ:
159 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
160 		break;
161 	case NL80211_BAND_2GHZ:
162 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
163 		break;
164 	default:
165 		BUG_ON(1);
166 		return false;
167 	}
168 
169 	return true;
170 }
171 
172 void ath9k_hw_reset_calibration(struct ath_hw *ah,
173 				struct ath9k_cal_list *currCal)
174 {
175 	int i;
176 
177 	ath9k_hw_setup_calibration(ah, currCal);
178 
179 	ah->cal_start_time = jiffies;
180 	currCal->calState = CAL_RUNNING;
181 
182 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
183 		ah->meas0.sign[i] = 0;
184 		ah->meas1.sign[i] = 0;
185 		ah->meas2.sign[i] = 0;
186 		ah->meas3.sign[i] = 0;
187 	}
188 
189 	ah->cal_samples = 0;
190 }
191 
192 /* This is done for the currently configured channel */
193 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
194 {
195 	struct ath_common *common = ath9k_hw_common(ah);
196 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
197 
198 	if (!ah->caldata)
199 		return true;
200 
201 	if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
202 		return true;
203 
204 	if (currCal == NULL)
205 		return true;
206 
207 	if (currCal->calState != CAL_DONE) {
208 		ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
209 			currCal->calState);
210 		return true;
211 	}
212 
213 	currCal = ah->cal_list;
214 	do {
215 		ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
216 			currCal->calData->calType,
217 			ah->curchan->chan->center_freq);
218 
219 		ah->caldata->CalValid &= ~currCal->calData->calType;
220 		currCal->calState = CAL_WAITING;
221 
222 		currCal = currCal->calNext;
223 	} while (currCal != ah->cal_list);
224 
225 	return false;
226 }
227 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
228 
229 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
230 {
231 	if (ah->caldata)
232 		set_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
233 
234 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
235 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
236 
237 	if (update)
238 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
239 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
240 	else
241 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
242 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
243 
244 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
245 }
246 
247 int ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
248 {
249 	struct ath9k_nfcal_hist *h = NULL;
250 	unsigned i, j;
251 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
252 	struct ath_common *common = ath9k_hw_common(ah);
253 	s16 default_nf = ath9k_hw_get_nf_limits(ah, chan)->nominal;
254 	u32 bb_agc_ctl = REG_READ(ah, AR_PHY_AGC_CONTROL(ah));
255 
256 	if (ah->caldata)
257 		h = ah->caldata->nfCalHist;
258 
259 	ENABLE_REG_RMW_BUFFER(ah);
260 	for (i = 0; i < NUM_NF_READINGS; i++) {
261 		if (chainmask & (1 << i)) {
262 			s16 nfval;
263 
264 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
265 				continue;
266 
267 			if (ah->nf_override)
268 				nfval = ah->nf_override;
269 			else if (h)
270 				nfval = h[i].privNF;
271 			else {
272 				/* Try to get calibrated noise floor value */
273 				nfval =
274 				    ath9k_hw_get_nf_limits(ah, chan)->cal[i];
275 				if (nfval > -60 || nfval < -127)
276 					nfval = default_nf;
277 			}
278 
279 			REG_RMW(ah, ah->nf_regs[i],
280 				(((u32) nfval << 1) & 0x1ff), 0x1ff);
281 		}
282 	}
283 
284 	/*
285 	 * stop NF cal if ongoing to ensure NF load completes immediately
286 	 * (or after end rx/tx frame if ongoing)
287 	 */
288 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
289 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
290 		REG_RMW_BUFFER_FLUSH(ah);
291 		ENABLE_REG_RMW_BUFFER(ah);
292 	}
293 
294 	/*
295 	 * Load software filtered NF value into baseband internal minCCApwr
296 	 * variable.
297 	 */
298 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
299 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
300 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
301 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
302 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
303 	REG_RMW_BUFFER_FLUSH(ah);
304 
305 	/*
306 	 * Wait for load to complete, should be fast, a few 10s of us.
307 	 * The max delay was changed from an original 250us to 22.2 msec.
308 	 * This would increase timeout to the longest possible frame
309 	 * (11n max length 22.1 msec)
310 	 */
311 	for (j = 0; j < 22200; j++) {
312 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) &
313 			      AR_PHY_AGC_CONTROL_NF) == 0)
314 			break;
315 		udelay(10);
316 	}
317 
318 	/*
319 	 * Restart NF so it can continue.
320 	 */
321 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
322 		ENABLE_REG_RMW_BUFFER(ah);
323 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_ENABLE_NF)
324 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
325 				    AR_PHY_AGC_CONTROL_ENABLE_NF);
326 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NO_UPDATE_NF)
327 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
328 				    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
329 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
330 		REG_RMW_BUFFER_FLUSH(ah);
331 	}
332 
333 	/*
334 	 * We timed out waiting for the noisefloor to load, probably due to an
335 	 * in-progress rx. Simply return here and allow the load plenty of time
336 	 * to complete before the next calibration interval.  We need to avoid
337 	 * trying to load -50 (which happens below) while the previous load is
338 	 * still in progress as this can cause rx deafness. Instead by returning
339 	 * here, the baseband nf cal will just be capped by our present
340 	 * noisefloor until the next calibration timer.
341 	 */
342 	if (j == 22200) {
343 		ath_dbg(common, ANY,
344 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
345 			REG_READ(ah, AR_PHY_AGC_CONTROL(ah)));
346 		return -ETIMEDOUT;
347 	}
348 
349 	/*
350 	 * Restore maxCCAPower register parameter again so that we're not capped
351 	 * by the median we just loaded.  This will be initial (and max) value
352 	 * of next noise floor calibration the baseband does.
353 	 */
354 	ENABLE_REG_RMW_BUFFER(ah);
355 	for (i = 0; i < NUM_NF_READINGS; i++) {
356 		if (chainmask & (1 << i)) {
357 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
358 				continue;
359 
360 			REG_RMW(ah, ah->nf_regs[i],
361 					(((u32) (-50) << 1) & 0x1ff), 0x1ff);
362 		}
363 	}
364 	REG_RMW_BUFFER_FLUSH(ah);
365 
366 	return 0;
367 }
368 EXPORT_SYMBOL(ath9k_hw_loadnf);
369 
370 
371 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
372 {
373 	struct ath_common *common = ath9k_hw_common(ah);
374 	struct ath_nf_limits *limit;
375 	int i;
376 
377 	if (IS_CHAN_2GHZ(ah->curchan))
378 		limit = &ah->nf_2g;
379 	else
380 		limit = &ah->nf_5g;
381 
382 	for (i = 0; i < NUM_NF_READINGS; i++) {
383 		if (!nf[i])
384 			continue;
385 
386 		ath_dbg(common, CALIBRATE,
387 			"NF calibrated [%s] [chain %d] is %d\n",
388 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
389 
390 		if (nf[i] > limit->max) {
391 			ath_dbg(common, CALIBRATE,
392 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
393 				i, nf[i], limit->max);
394 			nf[i] = limit->max;
395 		} else if (nf[i] < limit->min) {
396 			ath_dbg(common, CALIBRATE,
397 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
398 				i, nf[i], limit->min);
399 			nf[i] = limit->nominal;
400 		}
401 	}
402 }
403 
404 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
405 {
406 	struct ath_common *common = ath9k_hw_common(ah);
407 	int16_t nf, nfThresh;
408 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
409 	struct ath9k_nfcal_hist *h;
410 	struct ieee80211_channel *c = chan->chan;
411 	struct ath9k_hw_cal_data *caldata = ah->caldata;
412 
413 	if (REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF) {
414 		ath_dbg(common, CALIBRATE,
415 			"NF did not complete in calibration window\n");
416 		return false;
417 	}
418 
419 	ath9k_hw_do_getnf(ah, nfarray);
420 	ath9k_hw_nf_sanitize(ah, nfarray);
421 	nf = nfarray[0];
422 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
423 	    && nf > nfThresh) {
424 		ath_dbg(common, CALIBRATE,
425 			"noise floor failed detected; detected %d, threshold %d\n",
426 			nf, nfThresh);
427 	}
428 
429 	if (!caldata) {
430 		chan->noisefloor = nf;
431 		return false;
432 	}
433 
434 	h = caldata->nfCalHist;
435 	clear_bit(NFCAL_PENDING, &caldata->cal_flags);
436 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
437 	chan->noisefloor = h[0].privNF;
438 	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
439 	return true;
440 }
441 EXPORT_SYMBOL(ath9k_hw_getnf);
442 
443 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
444 				  struct ath9k_channel *chan)
445 {
446 	struct ath9k_nfcal_hist *h;
447 	int i, j, k = 0;
448 
449 	ah->caldata->channel = chan->channel;
450 	ah->caldata->channelFlags = chan->channelFlags;
451 	h = ah->caldata->nfCalHist;
452 	for (i = 0; i < NUM_NF_READINGS; i++) {
453 		h[i].currIndex = 0;
454 		h[i].privNF = ath9k_hw_get_default_nf(ah, chan, k);
455 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
456 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++)
457 			h[i].nfCalBuffer[j] = h[i].privNF;
458 		if (++k >= AR5416_MAX_CHAINS)
459 			k = 0;
460 	}
461 }
462 
463 
464 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
465 {
466 	struct ath9k_hw_cal_data *caldata = ah->caldata;
467 
468 	if (unlikely(!caldata))
469 		return;
470 
471 	/*
472 	 * If beacons are stuck, the most likely cause is interference.
473 	 * Triggering a noise floor calibration at this point helps the
474 	 * hardware adapt to a noisy environment much faster.
475 	 * To ensure that we recover from stuck beacons quickly, let
476 	 * the baseband update the internal NF value itself, similar to
477 	 * what is being done after a full reset.
478 	 */
479 	if (!test_bit(NFCAL_PENDING, &caldata->cal_flags))
480 		ath9k_hw_start_nfcal(ah, true);
481 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF))
482 		ath9k_hw_getnf(ah, ah->curchan);
483 
484 	set_bit(NFCAL_INTF, &caldata->cal_flags);
485 }
486 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
487 
488