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 
20 /* Common calibration code */
21 
22 #define ATH9K_NF_TOO_HIGH	-60
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 
67 static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
68 					      struct ath9k_hw_cal_data *cal,
69 					      int16_t *nfarray)
70 {
71 	struct ath_common *common = ath9k_hw_common(ah);
72 	struct ieee80211_conf *conf = &common->hw->conf;
73 	struct ath_nf_limits *limit;
74 	struct ath9k_nfcal_hist *h;
75 	bool high_nf_mid = false;
76 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
77 	int i;
78 
79 	h = cal->nfCalHist;
80 	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
81 
82 	for (i = 0; i < NUM_NF_READINGS; i++) {
83 		if (!(chainmask & (1 << i)) ||
84 		    ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf)))
85 			continue;
86 
87 		h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
88 
89 		if (++h[i].currIndex >= ATH9K_NF_CAL_HIST_MAX)
90 			h[i].currIndex = 0;
91 
92 		if (h[i].invalidNFcount > 0) {
93 			h[i].invalidNFcount--;
94 			h[i].privNF = nfarray[i];
95 		} else {
96 			h[i].privNF =
97 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
98 		}
99 
100 		if (!h[i].privNF)
101 			continue;
102 
103 		if (h[i].privNF > limit->max) {
104 			high_nf_mid = true;
105 
106 			ath_dbg(common, ATH_DBG_CALIBRATE,
107 				"NFmid[%d] (%d) > MAX (%d), %s\n",
108 				i, h[i].privNF, limit->max,
109 				(cal->nfcal_interference ?
110 				 "not corrected (due to interference)" :
111 				 "correcting to MAX"));
112 
113 			/*
114 			 * Normally we limit the average noise floor by the
115 			 * hardware specific maximum here. However if we have
116 			 * encountered stuck beacons because of interference,
117 			 * we bypass this limit here in order to better deal
118 			 * with our environment.
119 			 */
120 			if (!cal->nfcal_interference)
121 				h[i].privNF = limit->max;
122 		}
123 	}
124 
125 	/*
126 	 * If the noise floor seems normal for all chains, assume that
127 	 * there is no significant interference in the environment anymore.
128 	 * Re-enable the enforcement of the NF maximum again.
129 	 */
130 	if (!high_nf_mid)
131 		cal->nfcal_interference = false;
132 }
133 
134 static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
135 				   enum ieee80211_band band,
136 				   int16_t *nft)
137 {
138 	switch (band) {
139 	case IEEE80211_BAND_5GHZ:
140 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_5);
141 		break;
142 	case IEEE80211_BAND_2GHZ:
143 		*nft = (int8_t)ah->eep_ops->get_eeprom(ah, EEP_NFTHRESH_2);
144 		break;
145 	default:
146 		BUG_ON(1);
147 		return false;
148 	}
149 
150 	return true;
151 }
152 
153 void ath9k_hw_reset_calibration(struct ath_hw *ah,
154 				struct ath9k_cal_list *currCal)
155 {
156 	int i;
157 
158 	ath9k_hw_setup_calibration(ah, currCal);
159 
160 	currCal->calState = CAL_RUNNING;
161 
162 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
163 		ah->meas0.sign[i] = 0;
164 		ah->meas1.sign[i] = 0;
165 		ah->meas2.sign[i] = 0;
166 		ah->meas3.sign[i] = 0;
167 	}
168 
169 	ah->cal_samples = 0;
170 }
171 
172 /* This is done for the currently configured channel */
173 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
174 {
175 	struct ath_common *common = ath9k_hw_common(ah);
176 	struct ieee80211_conf *conf = &common->hw->conf;
177 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
178 
179 	if (!ah->caldata)
180 		return true;
181 
182 	if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
183 		return true;
184 
185 	if (currCal == NULL)
186 		return true;
187 
188 	if (currCal->calState != CAL_DONE) {
189 		ath_dbg(common, ATH_DBG_CALIBRATE,
190 			"Calibration state incorrect, %d\n",
191 			currCal->calState);
192 		return true;
193 	}
194 
195 	if (!(ah->supp_cals & currCal->calData->calType))
196 		return true;
197 
198 	ath_dbg(common, ATH_DBG_CALIBRATE,
199 		"Resetting Cal %d state for channel %u\n",
200 		currCal->calData->calType, conf->channel->center_freq);
201 
202 	ah->caldata->CalValid &= ~currCal->calData->calType;
203 	currCal->calState = CAL_WAITING;
204 
205 	return false;
206 }
207 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
208 
209 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
210 {
211 	if (ah->caldata)
212 		ah->caldata->nfcal_pending = true;
213 
214 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
215 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
216 
217 	if (update)
218 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
219 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
220 	else
221 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
222 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
223 
224 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
225 }
226 
227 void ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
228 {
229 	struct ath9k_nfcal_hist *h = NULL;
230 	unsigned i, j;
231 	int32_t val;
232 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
233 	struct ath_common *common = ath9k_hw_common(ah);
234 	struct ieee80211_conf *conf = &common->hw->conf;
235 	s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
236 
237 	if (ah->caldata)
238 		h = ah->caldata->nfCalHist;
239 
240 	for (i = 0; i < NUM_NF_READINGS; i++) {
241 		if (chainmask & (1 << i)) {
242 			s16 nfval;
243 
244 			if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
245 				continue;
246 
247 			if (h)
248 				nfval = h[i].privNF;
249 			else
250 				nfval = default_nf;
251 
252 			val = REG_READ(ah, ah->nf_regs[i]);
253 			val &= 0xFFFFFE00;
254 			val |= (((u32) nfval << 1) & 0x1ff);
255 			REG_WRITE(ah, ah->nf_regs[i], val);
256 		}
257 	}
258 
259 	/*
260 	 * Load software filtered NF value into baseband internal minCCApwr
261 	 * variable.
262 	 */
263 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
264 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
265 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
266 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
267 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
268 
269 	/*
270 	 * Wait for load to complete, should be fast, a few 10s of us.
271 	 * The max delay was changed from an original 250us to 10000us
272 	 * since 250us often results in NF load timeout and causes deaf
273 	 * condition during stress testing 12/12/2009
274 	 */
275 	for (j = 0; j < 10000; j++) {
276 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
277 		     AR_PHY_AGC_CONTROL_NF) == 0)
278 			break;
279 		udelay(10);
280 	}
281 
282 	/*
283 	 * We timed out waiting for the noisefloor to load, probably due to an
284 	 * in-progress rx. Simply return here and allow the load plenty of time
285 	 * to complete before the next calibration interval.  We need to avoid
286 	 * trying to load -50 (which happens below) while the previous load is
287 	 * still in progress as this can cause rx deafness. Instead by returning
288 	 * here, the baseband nf cal will just be capped by our present
289 	 * noisefloor until the next calibration timer.
290 	 */
291 	if (j == 10000) {
292 		ath_dbg(common, ATH_DBG_ANY,
293 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
294 			REG_READ(ah, AR_PHY_AGC_CONTROL));
295 		return;
296 	}
297 
298 	/*
299 	 * Restore maxCCAPower register parameter again so that we're not capped
300 	 * by the median we just loaded.  This will be initial (and max) value
301 	 * of next noise floor calibration the baseband does.
302 	 */
303 	ENABLE_REGWRITE_BUFFER(ah);
304 	for (i = 0; i < NUM_NF_READINGS; i++) {
305 		if (chainmask & (1 << i)) {
306 			if ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))
307 				continue;
308 
309 			val = REG_READ(ah, ah->nf_regs[i]);
310 			val &= 0xFFFFFE00;
311 			val |= (((u32) (-50) << 1) & 0x1ff);
312 			REG_WRITE(ah, ah->nf_regs[i], val);
313 		}
314 	}
315 	REGWRITE_BUFFER_FLUSH(ah);
316 }
317 
318 
319 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
320 {
321 	struct ath_common *common = ath9k_hw_common(ah);
322 	struct ath_nf_limits *limit;
323 	int i;
324 
325 	if (IS_CHAN_2GHZ(ah->curchan))
326 		limit = &ah->nf_2g;
327 	else
328 		limit = &ah->nf_5g;
329 
330 	for (i = 0; i < NUM_NF_READINGS; i++) {
331 		if (!nf[i])
332 			continue;
333 
334 		ath_dbg(common, ATH_DBG_CALIBRATE,
335 			"NF calibrated [%s] [chain %d] is %d\n",
336 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
337 
338 		if (nf[i] > ATH9K_NF_TOO_HIGH) {
339 			ath_dbg(common, ATH_DBG_CALIBRATE,
340 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
341 				i, nf[i], ATH9K_NF_TOO_HIGH);
342 			nf[i] = limit->max;
343 		} else if (nf[i] < limit->min) {
344 			ath_dbg(common, ATH_DBG_CALIBRATE,
345 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
346 				i, nf[i], limit->min);
347 			nf[i] = limit->nominal;
348 		}
349 	}
350 }
351 
352 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
353 {
354 	struct ath_common *common = ath9k_hw_common(ah);
355 	int16_t nf, nfThresh;
356 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
357 	struct ath9k_nfcal_hist *h;
358 	struct ieee80211_channel *c = chan->chan;
359 	struct ath9k_hw_cal_data *caldata = ah->caldata;
360 
361 	chan->channelFlags &= (~CHANNEL_CW_INT);
362 	if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
363 		ath_dbg(common, ATH_DBG_CALIBRATE,
364 			"NF did not complete in calibration window\n");
365 		return false;
366 	}
367 
368 	ath9k_hw_do_getnf(ah, nfarray);
369 	ath9k_hw_nf_sanitize(ah, nfarray);
370 	nf = nfarray[0];
371 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
372 	    && nf > nfThresh) {
373 		ath_dbg(common, ATH_DBG_CALIBRATE,
374 			"noise floor failed detected; detected %d, threshold %d\n",
375 			nf, nfThresh);
376 		chan->channelFlags |= CHANNEL_CW_INT;
377 	}
378 
379 	if (!caldata) {
380 		chan->noisefloor = nf;
381 		return false;
382 	}
383 
384 	h = caldata->nfCalHist;
385 	caldata->nfcal_pending = false;
386 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
387 	chan->noisefloor = h[0].privNF;
388 	return true;
389 }
390 
391 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
392 				  struct ath9k_channel *chan)
393 {
394 	struct ath9k_nfcal_hist *h;
395 	s16 default_nf;
396 	int i, j;
397 
398 	ah->caldata->channel = chan->channel;
399 	ah->caldata->channelFlags = chan->channelFlags & ~CHANNEL_CW_INT;
400 	h = ah->caldata->nfCalHist;
401 	default_nf = ath9k_hw_get_default_nf(ah, chan);
402 	for (i = 0; i < NUM_NF_READINGS; i++) {
403 		h[i].currIndex = 0;
404 		h[i].privNF = default_nf;
405 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
406 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++) {
407 			h[i].nfCalBuffer[j] = default_nf;
408 		}
409 	}
410 }
411 
412 
413 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
414 {
415 	struct ath9k_hw_cal_data *caldata = ah->caldata;
416 
417 	if (unlikely(!caldata))
418 		return;
419 
420 	/*
421 	 * If beacons are stuck, the most likely cause is interference.
422 	 * Triggering a noise floor calibration at this point helps the
423 	 * hardware adapt to a noisy environment much faster.
424 	 * To ensure that we recover from stuck beacons quickly, let
425 	 * the baseband update the internal NF value itself, similar to
426 	 * what is being done after a full reset.
427 	 */
428 	if (!caldata->nfcal_pending)
429 		ath9k_hw_start_nfcal(ah, true);
430 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF))
431 		ath9k_hw_getnf(ah, ah->curchan);
432 
433 	caldata->nfcal_interference = true;
434 }
435 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
436 
437