xref: /linux/drivers/net/wireless/ath/ath9k/calib.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 {
63 	return ath9k_hw_get_nf_limits(ah, chan)->nominal;
64 }
65 
66 s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan)
67 {
68 	s8 noise = ATH_DEFAULT_NOISE_FLOOR;
69 
70 	if (chan && chan->noisefloor) {
71 		s8 delta = chan->noisefloor -
72 			   ath9k_hw_get_default_nf(ah, chan);
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 				(cal->nfcal_interference ?
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 (!cal->nfcal_interference)
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 		cal->nfcal_interference = false;
144 }
145 
146 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
147 				   enum ieee80211_band band,
148 				   int16_t *nft)
149 {
150 	switch (band) {
151 	case IEEE80211_BAND_5GHZ:
152 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
153 		break;
154 	case IEEE80211_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 	currCal->calState = CAL_RUNNING;
173 
174 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
175 		ah->meas0.sign[i] = 0;
176 		ah->meas1.sign[i] = 0;
177 		ah->meas2.sign[i] = 0;
178 		ah->meas3.sign[i] = 0;
179 	}
180 
181 	ah->cal_samples = 0;
182 }
183 
184 /* This is done for the currently configured channel */
185 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
186 {
187 	struct ath_common *common = ath9k_hw_common(ah);
188 	struct ieee80211_conf *conf = &common->hw->conf;
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 	if (!(ah->supp_cals & currCal->calData->calType))
207 		return true;
208 
209 	ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
210 		currCal->calData->calType, conf->channel->center_freq);
211 
212 	ah->caldata->CalValid &= ~currCal->calData->calType;
213 	currCal->calState = CAL_WAITING;
214 
215 	return false;
216 }
217 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
218 
219 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
220 {
221 	if (ah->caldata)
222 		ah->caldata->nfcal_pending = true;
223 
224 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
225 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
226 
227 	if (update)
228 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
229 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
230 	else
231 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
232 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
233 
234 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
235 }
236 
237 void ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
238 {
239 	struct ath9k_nfcal_hist *h = NULL;
240 	unsigned i, j;
241 	int32_t val;
242 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
243 	struct ath_common *common = ath9k_hw_common(ah);
244 	struct ieee80211_conf *conf = &common->hw->conf;
245 	s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
246 
247 	if (ah->caldata)
248 		h = ah->caldata->nfCalHist;
249 
250 	for (i = 0; i < NUM_NF_READINGS; i++) {
251 		if (chainmask & (1 << i)) {
252 			s16 nfval;
253 
254 			if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
255 				continue;
256 
257 			if (h)
258 				nfval = h[i].privNF;
259 			else
260 				nfval = default_nf;
261 
262 			val = REG_READ(ah, ah->nf_regs[i]);
263 			val &= 0xFFFFFE00;
264 			val |= (((u32) nfval << 1) & 0x1ff);
265 			REG_WRITE(ah, ah->nf_regs[i], val);
266 		}
267 	}
268 
269 	/*
270 	 * Load software filtered NF value into baseband internal minCCApwr
271 	 * variable.
272 	 */
273 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
274 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
275 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
276 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
277 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
278 
279 	/*
280 	 * Wait for load to complete, should be fast, a few 10s of us.
281 	 * The max delay was changed from an original 250us to 10000us
282 	 * since 250us often results in NF load timeout and causes deaf
283 	 * condition during stress testing 12/12/2009
284 	 */
285 	for (j = 0; j < 10000; j++) {
286 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
287 		     AR_PHY_AGC_CONTROL_NF) == 0)
288 			break;
289 		udelay(10);
290 	}
291 
292 	/*
293 	 * We timed out waiting for the noisefloor to load, probably due to an
294 	 * in-progress rx. Simply return here and allow the load plenty of time
295 	 * to complete before the next calibration interval.  We need to avoid
296 	 * trying to load -50 (which happens below) while the previous load is
297 	 * still in progress as this can cause rx deafness. Instead by returning
298 	 * here, the baseband nf cal will just be capped by our present
299 	 * noisefloor until the next calibration timer.
300 	 */
301 	if (j == 10000) {
302 		ath_dbg(common, ANY,
303 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
304 			REG_READ(ah, AR_PHY_AGC_CONTROL));
305 		return;
306 	}
307 
308 	/*
309 	 * Restore maxCCAPower register parameter again so that we're not capped
310 	 * by the median we just loaded.  This will be initial (and max) value
311 	 * of next noise floor calibration the baseband does.
312 	 */
313 	ENABLE_REGWRITE_BUFFER(ah);
314 	for (i = 0; i < NUM_NF_READINGS; i++) {
315 		if (chainmask & (1 << i)) {
316 			if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
317 				continue;
318 
319 			val = REG_READ(ah, ah->nf_regs[i]);
320 			val &= 0xFFFFFE00;
321 			val |= (((u32) (-50) << 1) & 0x1ff);
322 			REG_WRITE(ah, ah->nf_regs[i], val);
323 		}
324 	}
325 	REGWRITE_BUFFER_FLUSH(ah);
326 }
327 
328 
329 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
330 {
331 	struct ath_common *common = ath9k_hw_common(ah);
332 	struct ath_nf_limits *limit;
333 	int i;
334 
335 	if (IS_CHAN_2GHZ(ah->curchan))
336 		limit = &ah->nf_2g;
337 	else
338 		limit = &ah->nf_5g;
339 
340 	for (i = 0; i < NUM_NF_READINGS; i++) {
341 		if (!nf[i])
342 			continue;
343 
344 		ath_dbg(common, CALIBRATE,
345 			"NF calibrated [%s] [chain %d] is %d\n",
346 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
347 
348 		if (nf[i] > limit->max) {
349 			ath_dbg(common, CALIBRATE,
350 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
351 				i, nf[i], limit->max);
352 			nf[i] = limit->max;
353 		} else if (nf[i] < limit->min) {
354 			ath_dbg(common, CALIBRATE,
355 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
356 				i, nf[i], limit->min);
357 			nf[i] = limit->nominal;
358 		}
359 	}
360 }
361 
362 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
363 {
364 	struct ath_common *common = ath9k_hw_common(ah);
365 	int16_t nf, nfThresh;
366 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
367 	struct ath9k_nfcal_hist *h;
368 	struct ieee80211_channel *c = chan->chan;
369 	struct ath9k_hw_cal_data *caldata = ah->caldata;
370 
371 	chan->channelFlags &= (~CHANNEL_CW_INT);
372 	if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
373 		ath_dbg(common, CALIBRATE,
374 			"NF did not complete in calibration window\n");
375 		return false;
376 	}
377 
378 	ath9k_hw_do_getnf(ah, nfarray);
379 	ath9k_hw_nf_sanitize(ah, nfarray);
380 	nf = nfarray[0];
381 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
382 	    && nf > nfThresh) {
383 		ath_dbg(common, CALIBRATE,
384 			"noise floor failed detected; detected %d, threshold %d\n",
385 			nf, nfThresh);
386 		chan->channelFlags |= CHANNEL_CW_INT;
387 	}
388 
389 	if (!caldata) {
390 		chan->noisefloor = nf;
391 		ah->noise = ath9k_hw_getchan_noise(ah, chan);
392 		return false;
393 	}
394 
395 	h = caldata->nfCalHist;
396 	caldata->nfcal_pending = false;
397 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
398 	chan->noisefloor = h[0].privNF;
399 	ah->noise = ath9k_hw_getchan_noise(ah, chan);
400 	return true;
401 }
402 EXPORT_SYMBOL(ath9k_hw_getnf);
403 
404 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
405 				  struct ath9k_channel *chan)
406 {
407 	struct ath9k_nfcal_hist *h;
408 	s16 default_nf;
409 	int i, j;
410 
411 	ah->caldata->channel = chan->channel;
412 	ah->caldata->channelFlags = chan->channelFlags & ~CHANNEL_CW_INT;
413 	h = ah->caldata->nfCalHist;
414 	default_nf = ath9k_hw_get_default_nf(ah, chan);
415 	for (i = 0; i < NUM_NF_READINGS; i++) {
416 		h[i].currIndex = 0;
417 		h[i].privNF = default_nf;
418 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
419 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++) {
420 			h[i].nfCalBuffer[j] = default_nf;
421 		}
422 	}
423 }
424 
425 
426 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
427 {
428 	struct ath9k_hw_cal_data *caldata = ah->caldata;
429 
430 	if (unlikely(!caldata))
431 		return;
432 
433 	/*
434 	 * If beacons are stuck, the most likely cause is interference.
435 	 * Triggering a noise floor calibration at this point helps the
436 	 * hardware adapt to a noisy environment much faster.
437 	 * To ensure that we recover from stuck beacons quickly, let
438 	 * the baseband update the internal NF value itself, similar to
439 	 * what is being done after a full reset.
440 	 */
441 	if (!caldata->nfcal_pending)
442 		ath9k_hw_start_nfcal(ah, true);
443 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF))
444 		ath9k_hw_getnf(ah, ah->curchan);
445 
446 	caldata->nfcal_interference = true;
447 }
448 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
449 
450