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 	currCal->calState = CAL_RUNNING;
180 
181 	for (i = 0; i < AR5416_MAX_CHAINS; i++) {
182 		ah->meas0.sign[i] = 0;
183 		ah->meas1.sign[i] = 0;
184 		ah->meas2.sign[i] = 0;
185 		ah->meas3.sign[i] = 0;
186 	}
187 
188 	ah->cal_samples = 0;
189 }
190 
191 /* This is done for the currently configured channel */
192 bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
193 {
194 	struct ath_common *common = ath9k_hw_common(ah);
195 	struct ath9k_cal_list *currCal = ah->cal_list_curr;
196 
197 	if (!ah->caldata)
198 		return true;
199 
200 	if (!AR_SREV_9100(ah) && !AR_SREV_9160_10_OR_LATER(ah))
201 		return true;
202 
203 	if (currCal == NULL)
204 		return true;
205 
206 	if (currCal->calState != CAL_DONE) {
207 		ath_dbg(common, CALIBRATE, "Calibration state incorrect, %d\n",
208 			currCal->calState);
209 		return true;
210 	}
211 
212 	if (!(ah->supp_cals & currCal->calData->calType))
213 		return true;
214 
215 	ath_dbg(common, CALIBRATE, "Resetting Cal %d state for channel %u\n",
216 		currCal->calData->calType, ah->curchan->chan->center_freq);
217 
218 	ah->caldata->CalValid &= ~currCal->calData->calType;
219 	currCal->calState = CAL_WAITING;
220 
221 	return false;
222 }
223 EXPORT_SYMBOL(ath9k_hw_reset_calvalid);
224 
225 void ath9k_hw_start_nfcal(struct ath_hw *ah, bool update)
226 {
227 	if (ah->caldata)
228 		set_bit(NFCAL_PENDING, &ah->caldata->cal_flags);
229 
230 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
231 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
232 
233 	if (update)
234 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
235 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
236 	else
237 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
238 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
239 
240 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
241 }
242 
243 int ath9k_hw_loadnf(struct ath_hw *ah, struct ath9k_channel *chan)
244 {
245 	struct ath9k_nfcal_hist *h = NULL;
246 	unsigned i, j;
247 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
248 	struct ath_common *common = ath9k_hw_common(ah);
249 	s16 default_nf = ath9k_hw_get_nf_limits(ah, chan)->nominal;
250 	u32 bb_agc_ctl = REG_READ(ah, AR_PHY_AGC_CONTROL);
251 
252 	if (ah->caldata)
253 		h = ah->caldata->nfCalHist;
254 
255 	ENABLE_REG_RMW_BUFFER(ah);
256 	for (i = 0; i < NUM_NF_READINGS; i++) {
257 		if (chainmask & (1 << i)) {
258 			s16 nfval;
259 
260 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
261 				continue;
262 
263 			if (ah->nf_override)
264 				nfval = ah->nf_override;
265 			else if (h)
266 				nfval = h[i].privNF;
267 			else {
268 				/* Try to get calibrated noise floor value */
269 				nfval =
270 				    ath9k_hw_get_nf_limits(ah, chan)->cal[i];
271 				if (nfval > -60 || nfval < -127)
272 					nfval = default_nf;
273 			}
274 
275 			REG_RMW(ah, ah->nf_regs[i],
276 				(((u32) nfval << 1) & 0x1ff), 0x1ff);
277 		}
278 	}
279 
280 	/*
281 	 * stop NF cal if ongoing to ensure NF load completes immediately
282 	 * (or after end rx/tx frame if ongoing)
283 	 */
284 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
285 		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
286 		REG_RMW_BUFFER_FLUSH(ah);
287 		ENABLE_REG_RMW_BUFFER(ah);
288 	}
289 
290 	/*
291 	 * Load software filtered NF value into baseband internal minCCApwr
292 	 * variable.
293 	 */
294 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
295 		    AR_PHY_AGC_CONTROL_ENABLE_NF);
296 	REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL,
297 		    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
298 	REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
299 	REG_RMW_BUFFER_FLUSH(ah);
300 
301 	/*
302 	 * Wait for load to complete, should be fast, a few 10s of us.
303 	 * The max delay was changed from an original 250us to 22.2 msec.
304 	 * This would increase timeout to the longest possible frame
305 	 * (11n max length 22.1 msec)
306 	 */
307 	for (j = 0; j < 22200; j++) {
308 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
309 			      AR_PHY_AGC_CONTROL_NF) == 0)
310 			break;
311 		udelay(10);
312 	}
313 
314 	/*
315 	 * Restart NF so it can continue.
316 	 */
317 	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
318 		ENABLE_REG_RMW_BUFFER(ah);
319 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_ENABLE_NF)
320 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
321 				    AR_PHY_AGC_CONTROL_ENABLE_NF);
322 		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NO_UPDATE_NF)
323 			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
324 				    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
325 		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
326 		REG_RMW_BUFFER_FLUSH(ah);
327 	}
328 
329 	/*
330 	 * We timed out waiting for the noisefloor to load, probably due to an
331 	 * in-progress rx. Simply return here and allow the load plenty of time
332 	 * to complete before the next calibration interval.  We need to avoid
333 	 * trying to load -50 (which happens below) while the previous load is
334 	 * still in progress as this can cause rx deafness. Instead by returning
335 	 * here, the baseband nf cal will just be capped by our present
336 	 * noisefloor until the next calibration timer.
337 	 */
338 	if (j == 22200) {
339 		ath_dbg(common, ANY,
340 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
341 			REG_READ(ah, AR_PHY_AGC_CONTROL));
342 		return -ETIMEDOUT;
343 	}
344 
345 	/*
346 	 * Restore maxCCAPower register parameter again so that we're not capped
347 	 * by the median we just loaded.  This will be initial (and max) value
348 	 * of next noise floor calibration the baseband does.
349 	 */
350 	ENABLE_REG_RMW_BUFFER(ah);
351 	for (i = 0; i < NUM_NF_READINGS; i++) {
352 		if (chainmask & (1 << i)) {
353 			if ((i >= AR5416_MAX_CHAINS) && !IS_CHAN_HT40(chan))
354 				continue;
355 
356 			REG_RMW(ah, ah->nf_regs[i],
357 					(((u32) (-50) << 1) & 0x1ff), 0x1ff);
358 		}
359 	}
360 	REG_RMW_BUFFER_FLUSH(ah);
361 
362 	return 0;
363 }
364 EXPORT_SYMBOL(ath9k_hw_loadnf);
365 
366 
367 static void ath9k_hw_nf_sanitize(struct ath_hw *ah, s16 *nf)
368 {
369 	struct ath_common *common = ath9k_hw_common(ah);
370 	struct ath_nf_limits *limit;
371 	int i;
372 
373 	if (IS_CHAN_2GHZ(ah->curchan))
374 		limit = &ah->nf_2g;
375 	else
376 		limit = &ah->nf_5g;
377 
378 	for (i = 0; i < NUM_NF_READINGS; i++) {
379 		if (!nf[i])
380 			continue;
381 
382 		ath_dbg(common, CALIBRATE,
383 			"NF calibrated [%s] [chain %d] is %d\n",
384 			(i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
385 
386 		if (nf[i] > limit->max) {
387 			ath_dbg(common, CALIBRATE,
388 				"NF[%d] (%d) > MAX (%d), correcting to MAX\n",
389 				i, nf[i], limit->max);
390 			nf[i] = limit->max;
391 		} else if (nf[i] < limit->min) {
392 			ath_dbg(common, CALIBRATE,
393 				"NF[%d] (%d) < MIN (%d), correcting to NOM\n",
394 				i, nf[i], limit->min);
395 			nf[i] = limit->nominal;
396 		}
397 	}
398 }
399 
400 bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan)
401 {
402 	struct ath_common *common = ath9k_hw_common(ah);
403 	int16_t nf, nfThresh;
404 	int16_t nfarray[NUM_NF_READINGS] = { 0 };
405 	struct ath9k_nfcal_hist *h;
406 	struct ieee80211_channel *c = chan->chan;
407 	struct ath9k_hw_cal_data *caldata = ah->caldata;
408 
409 	if (REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF) {
410 		ath_dbg(common, CALIBRATE,
411 			"NF did not complete in calibration window\n");
412 		return false;
413 	}
414 
415 	ath9k_hw_do_getnf(ah, nfarray);
416 	ath9k_hw_nf_sanitize(ah, nfarray);
417 	nf = nfarray[0];
418 	if (ath9k_hw_get_nf_thresh(ah, c->band, &nfThresh)
419 	    && nf > nfThresh) {
420 		ath_dbg(common, CALIBRATE,
421 			"noise floor failed detected; detected %d, threshold %d\n",
422 			nf, nfThresh);
423 	}
424 
425 	if (!caldata) {
426 		chan->noisefloor = nf;
427 		return false;
428 	}
429 
430 	h = caldata->nfCalHist;
431 	clear_bit(NFCAL_PENDING, &caldata->cal_flags);
432 	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
433 	chan->noisefloor = h[0].privNF;
434 	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
435 	return true;
436 }
437 EXPORT_SYMBOL(ath9k_hw_getnf);
438 
439 void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
440 				  struct ath9k_channel *chan)
441 {
442 	struct ath9k_nfcal_hist *h;
443 	int i, j, k = 0;
444 
445 	ah->caldata->channel = chan->channel;
446 	ah->caldata->channelFlags = chan->channelFlags;
447 	h = ah->caldata->nfCalHist;
448 	for (i = 0; i < NUM_NF_READINGS; i++) {
449 		h[i].currIndex = 0;
450 		h[i].privNF = ath9k_hw_get_default_nf(ah, chan, k);
451 		h[i].invalidNFcount = AR_PHY_CCA_FILTERWINDOW_LENGTH;
452 		for (j = 0; j < ATH9K_NF_CAL_HIST_MAX; j++)
453 			h[i].nfCalBuffer[j] = h[i].privNF;
454 		if (++k >= AR5416_MAX_CHAINS)
455 			k = 0;
456 	}
457 }
458 
459 
460 void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
461 {
462 	struct ath9k_hw_cal_data *caldata = ah->caldata;
463 
464 	if (unlikely(!caldata))
465 		return;
466 
467 	/*
468 	 * If beacons are stuck, the most likely cause is interference.
469 	 * Triggering a noise floor calibration at this point helps the
470 	 * hardware adapt to a noisy environment much faster.
471 	 * To ensure that we recover from stuck beacons quickly, let
472 	 * the baseband update the internal NF value itself, similar to
473 	 * what is being done after a full reset.
474 	 */
475 	if (!test_bit(NFCAL_PENDING, &caldata->cal_flags))
476 		ath9k_hw_start_nfcal(ah, true);
477 	else if (!(REG_READ(ah, AR_PHY_AGC_CONTROL) & AR_PHY_AGC_CONTROL_NF))
478 		ath9k_hw_getnf(ah, ah->curchan);
479 
480 	set_bit(NFCAL_INTF, &caldata->cal_flags);
481 }
482 EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
483 
484