xref: /linux/drivers/net/wireless/ath/ath9k/calib.c (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
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/sort.h>
20 #include <linux/export.h>
21 
22 /* Common calibration code */
23 
24 static int rcmp_i16(const void *x, const void *y)
25 {
26 	/* Sort in reverse order. */
27 	return *(int16_t *)y - *(int16_t *)x;
28 }
29 
30 static int16_t ath9k_hw_get_nf_hist_mid(int16_t *nfCalBuffer)
31 {
32 	int16_t nfcal[ATH9K_NF_CAL_HIST_MAX];
33 
34 	memcpy(nfcal, nfCalBuffer, sizeof(nfcal));
35 	sort(nfcal, ATH9K_NF_CAL_HIST_MAX, sizeof(int16_t), rcmp_i16, NULL);
36 
37 	return nfcal[(ATH9K_NF_CAL_HIST_MAX - 1) >> 1];
38 }
39 
40 static struct ath_nf_limits *ath9k_hw_get_nf_limits(struct ath_hw *ah,
41 						    struct ath9k_channel *chan)
42 {
43 	struct ath_nf_limits *limit;
44 
45 	if (!chan || IS_CHAN_2GHZ(chan))
46 		limit = &ah->nf_2g;
47 	else
48 		limit = &ah->nf_5g;
49 
50 	return limit;
51 }
52 
53 static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
54 				   struct ath9k_channel *chan,
55 				   int chain)
56 {
57 	s16 calib_nf = ath9k_hw_get_nf_limits(ah, chan)->cal[chain];
58 
59 	if (calib_nf)
60 		return calib_nf;
61 	else
62 		return ath9k_hw_get_nf_limits(ah, chan)->nominal;
63 }
64 
65 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan,
66 			   s16 nf)
67 {
68 	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
69 
70 	if (nf) {
71 		s8 delta = nf - ATH9K_NF_CAL_NOISE_THRESH -
72 			   ath9k_hw_get_default_nf(ah, chan, 0);
73 		if (delta > 0)
74 			noise += delta;
75 	}
76 	return noise;
77 }
78 EXPORT_SYMBOL(ath9k_hw_getchan_noise);
79 
80 static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
81 					      struct ath9k_hw_cal_data *cal,
82 					      int16_t *nfarray)
83 {
84 	struct ath_common *common = ath9k_hw_common(ah);
85 	struct ath_nf_limits *limit;
86 	struct ath9k_nfcal_hist *h;
87 	bool high_nf_mid = false;
88 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
89 	int i;
90 
91 	h = cal->nfCalHist;
92 	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
93 
94 	for (i = 0; i < NUM_NF_READINGS; i++) {
95 		if (!(chainmask & (1 << i)) ||
96 		    ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(ah->curchan)))
97 			continue;
98 
99 		h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
100 
101 		if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
102 			h[i].currIndex = 0;
103 
104 		if (h[i].invalidNFcount > 0) {
105 			h[i].invalidNFcount--;
106 			h[i].privNF = nfarray[i];
107 		} else {
108 			h[i].privNF =
109 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
110 		}
111 
112 		if (!h[i].privNF)
113 			continue;
114 
115 		if (h[i].privNF > limit->max) {
116 			high_nf_mid = true;
117 
118 			ath_dbg(common, CALIBRATE,
119 				"NFmid[%d] (%d) > MAX (%d), %s\n",
120 				i, h[i].privNF, limit->max,
121 				(test_bit(NFCAL_INTF, &cal->cal_flags) ?
122 				 "not corrected (due to interference)" :
123 				 "correcting to MAX"));
124 
125 			/*
126 			 * Normally we limit the average noise floor by the
127 			 * hardware specific maximum here. However if we have
128 			 * encountered stuck beacons because of interference,
129 			 * we bypass this limit here in order to better deal
130 			 * with our environment.
131 			 */
132 			if (!test_bit(NFCAL_INTF, &cal->cal_flags))
133 				h[i].privNF = limit->max;
134 		}
135 	}
136 
137 	/*
138 	 * If the noise floor seems normal for all chains, assume that
139 	 * there is no significant interference in the environment anymore.
140 	 * Re-enable the enforcement of the NF maximum again.
141 	 */
142 	if (!high_nf_mid)
143 		clear_bit(NFCAL_INTF, &cal->cal_flags);
144 }
145 
146 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
147 				   enum nl80211_band band,
148 				   int16_t *nft)
149 {
150 	switch (band) {
151 	case NL80211_BAND_5GHZ:
152 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
153 		break;
154 	case NL80211_BAND_2GHZ:
155 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
156 		break;
157 	default:
158 		BUG_ON(1);
159 		return false;
160 	}
161 
162 	return true;
163 }
164 
165 void ath9k_hw_reset_calibration(struct ath_hw *ah,
166 				struct ath9k_cal_list *currCal)
167 {
168 	int i;
169 
170 	ath9k_hw_setup_calibration(ah, currCal);
171 
172 	ah->cal_start_time = jiffies;
173 	currCal->calState = CAL_RUNNING;
174 
175 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
176 		ah->meas0.sign[i] = 0;
177 		ah->meas1.sign[i] = 0;
178 		ah->meas2.sign[i] = 0;
179 		ah->meas3.sign[i] = 0;
180 	}
181 
182 	ah->cal_samples = 0;
183 }
184 
185 /* This is done for the currently configured channel */
186 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
187 {
188 	struct ath_common *common = ath9k_hw_common(ah);
189 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
190 
191 	if (!ah->caldata)
192 		return true;
193 
194 	if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
195 		return true;
196 
197 	if (currCal == NULL)
198 		return true;
199 
200 	if (currCal->calState != CAL_DONE) {
201 		ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
202 			currCal->calState);
203 		return true;
204 	}
205 
206 	currCal = ah->cal_list;
207 	do {
208 		ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
209 			currCal->calData->calType,
210 			ah->curchan->chan->center_freq);
211 
212 		ah->caldata->CalValid &= ~currCal->calData->calType;
213 		currCal->calState = CAL_WAITING;
214 
215 		currCal = currCal->calNext;
216 	} while (currCal != ah->cal_list);
217 
218 	return false;
219 }
220 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
221 
222 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
223 {
224 	if (ah->caldata)
225 		set_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
226 
227 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
228 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
229 
230 	if (update)
231 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
232 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
233 	else
234 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
235 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
236 
237 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
238 }
239 
240 int ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
241 {
242 	struct ath9k_nfcal_hist *h = NULL;
243 	unsigned i, j;
244 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
245 	struct ath_common *common = ath9k_hw_common(ah);
246 	s16 default_nf = ath9k_hw_get_nf_limits(ah, chan)->nominal;
247 	u32 bb_agc_ctl = REG_READ(ah, AR_PHY_AGC_CONTROL(ah));
248 
249 	if (ah->caldata)
250 		h = ah->caldata->nfCalHist;
251 
252 	ENABLE_REG_RMW_BUFFER(ah);
253 	for (i = 0; i < NUM_NF_READINGS; i++) {
254 		if (chainmask & (1 << i)) {
255 			s16 nfval;
256 
257 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
258 				continue;
259 
260 			if (ah->nf_override)
261 				nfval = ah->nf_override;
262 			else if (h)
263 				nfval = h[i].privNF;
264 			else {
265 				/* Try to get calibrated noise floor value */
266 				nfval =
267 				    ath9k_hw_get_nf_limits(ah, chan)->cal[i];
268 				if (nfval > -60 || nfval < -127)
269 					nfval = default_nf;
270 			}
271 
272 			REG_RMW(ah, ah->nf_regs[i],
273 				(((u32) nfval << 1) & 0x1ff), 0x1ff);
274 		}
275 	}
276 
277 	/*
278 	 * stop NF cal if ongoing to ensure NF load completes immediately
279 	 * (or after end rx/tx frame if ongoing)
280 	 */
281 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
282 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
283 		REG_RMW_BUFFER_FLUSH(ah);
284 		ENABLE_REG_RMW_BUFFER(ah);
285 	}
286 
287 	/*
288 	 * Load software filtered NF value into baseband internal minCCApwr
289 	 * variable.
290 	 */
291 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
292 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
293 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL(ah),
294 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
295 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
296 	REG_RMW_BUFFER_FLUSH(ah);
297 
298 	/*
299 	 * Wait for load to complete, should be fast, a few 10s of us.
300 	 * The max delay was changed from an original 250us to 22.2 msec.
301 	 * This would increase timeout to the longest possible frame
302 	 * (11n max length 22.1 msec)
303 	 */
304 	for (j = 0; j < 22200; j++) {
305 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) &
306 			      AR_PHY_AGC_CONTROL_NF) == 0)
307 			break;
308 		udelay(10);
309 	}
310 
311 	/*
312 	 * Restart NF so it can continue.
313 	 */
314 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
315 		ENABLE_REG_RMW_BUFFER(ah);
316 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_ENABLE_NF)
317 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
318 				    AR_PHY_AGC_CONTROL_ENABLE_NF);
319 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NO_UPDATE_NF)
320 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah),
321 				    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
322 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL(ah), AR_PHY_AGC_CONTROL_NF);
323 		REG_RMW_BUFFER_FLUSH(ah);
324 	}
325 
326 	/*
327 	 * We timed out waiting for the noisefloor to load, probably due to an
328 	 * in-progress rx. Simply return here and allow the load plenty of time
329 	 * to complete before the next calibration interval.  We need to avoid
330 	 * trying to load -50 (which happens below) while the previous load is
331 	 * still in progress as this can cause rx deafness. Instead by returning
332 	 * here, the baseband nf cal will just be capped by our present
333 	 * noisefloor until the next calibration timer.
334 	 */
335 	if (j == 22200) {
336 		ath_dbg(common, ANY,
337 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
338 			REG_READ(ah, AR_PHY_AGC_CONTROL(ah)));
339 		return -ETIMEDOUT;
340 	}
341 
342 	/*
343 	 * Restore maxCCAPower register parameter again so that we're not capped
344 	 * by the median we just loaded.  This will be initial (and max) value
345 	 * of next noise floor calibration the baseband does.
346 	 */
347 	ENABLE_REG_RMW_BUFFER(ah);
348 	for (i = 0; i < NUM_NF_READINGS; i++) {
349 		if (chainmask & (1 << i)) {
350 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
351 				continue;
352 
353 			REG_RMW(ah, ah->nf_regs[i],
354 					(((u32) (-50) << 1) & 0x1ff), 0x1ff);
355 		}
356 	}
357 	REG_RMW_BUFFER_FLUSH(ah);
358 
359 	return 0;
360 }
361 EXPORT_SYMBOL(ath9k_hw_loadnf);
362 
363 
364 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
365 {
366 	struct ath_common *common = ath9k_hw_common(ah);
367 	struct ath_nf_limits *limit;
368 	int i;
369 
370 	if (IS_CHAN_2GHZ(ah->curchan))
371 		limit = &ah->nf_2g;
372 	else
373 		limit = &ah->nf_5g;
374 
375 	for (i = 0; i < NUM_NF_READINGS; i++) {
376 		if (!nf[i])
377 			continue;
378 
379 		ath_dbg(common, CALIBRATE,
380 			"NF calibrated [%s] [chain %d] is %d\n",
381 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
382 
383 		if (nf[i] > limit->max) {
384 			ath_dbg(common, CALIBRATE,
385 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
386 				i, nf[i], limit->max);
387 			nf[i] = limit->max;
388 		} else if (nf[i] < limit->min) {
389 			ath_dbg(common, CALIBRATE,
390 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
391 				i, nf[i], limit->min);
392 			nf[i] = limit->nominal;
393 		}
394 	}
395 }
396 
397 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
398 {
399 	struct ath_common *common = ath9k_hw_common(ah);
400 	int16_t nf, nfThresh;
401 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
402 	struct ath9k_nfcal_hist *h;
403 	struct ieee80211_channel *c = chan->chan;
404 	struct ath9k_hw_cal_data *caldata = ah->caldata;
405 
406 	if (REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF) {
407 		ath_dbg(common, CALIBRATE,
408 			"NF did not complete in calibration window\n");
409 		return false;
410 	}
411 
412 	ath9k_hw_do_getnf(ah, nfarray);
413 	ath9k_hw_nf_sanitize(ah, nfarray);
414 	nf = nfarray[0];
415 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
416 	    && nf > nfThresh) {
417 		ath_dbg(common, CALIBRATE,
418 			"noise floor failed detected; detected %d, threshold %d\n",
419 			nf, nfThresh);
420 	}
421 
422 	if (!caldata) {
423 		chan->noisefloor = nf;
424 		return false;
425 	}
426 
427 	h = caldata->nfCalHist;
428 	clear_bit(NFCAL_PENDING, &caldata->cal_flags);
429 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
430 	chan->noisefloor = h[0].privNF;
431 	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
432 	return true;
433 }
434 EXPORT_SYMBOL(ath9k_hw_getnf);
435 
436 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
437 				  struct ath9k_channel *chan)
438 {
439 	struct ath9k_nfcal_hist *h;
440 	int i, j, k = 0;
441 
442 	ah->caldata->channel = chan->channel;
443 	ah->caldata->channelFlags = chan->channelFlags;
444 	h = ah->caldata->nfCalHist;
445 	for (i = 0; i < NUM_NF_READINGS; i++) {
446 		h[i].currIndex = 0;
447 		h[i].privNF = ath9k_hw_get_default_nf(ah, chan, k);
448 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
449 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++)
450 			h[i].nfCalBuffer[j] = h[i].privNF;
451 		if (++k >= AR5416_MAX_CHAINS)
452 			k = 0;
453 	}
454 }
455 
456 
457 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
458 {
459 	struct ath9k_hw_cal_data *caldata = ah->caldata;
460 
461 	if (unlikely(!caldata))
462 		return;
463 
464 	/*
465 	 * If beacons are stuck, the most likely cause is interference.
466 	 * Triggering a noise floor calibration at this point helps the
467 	 * hardware adapt to a noisy environment much faster.
468 	 * To ensure that we recover from stuck beacons quickly, let
469 	 * the baseband update the internal NF value itself, similar to
470 	 * what is being done after a full reset.
471 	 */
472 	if (!test_bit(NFCAL_PENDING, &caldata->cal_flags))
473 		ath9k_hw_start_nfcal(ah, true);
474 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL(ah)) & AR_PHY_AGC_CONTROL_NF))
475 		ath9k_hw_getnf(ah, ah->curchan);
476 
477 	set_bit(NFCAL_INTF, &caldata->cal_flags);
478 }
479 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
480 
481