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62 
63 #include <linux/slab.h>
64 #include <net/mac80211.h>
65 
66 #include "common.h"
67 #include "4965.h"
68 
69 /*****************************************************************************
70  * INIT calibrations framework
71  *****************************************************************************/
72 
73 struct stats_general_data {
74 	u32 beacon_silence_rssi_a;
75 	u32 beacon_silence_rssi_b;
76 	u32 beacon_silence_rssi_c;
77 	u32 beacon_energy_a;
78 	u32 beacon_energy_b;
79 	u32 beacon_energy_c;
80 };
81 
82 /*****************************************************************************
83  * RUNTIME calibrations framework
84  *****************************************************************************/
85 
86 /* "false alarms" are signals that our DSP tries to lock onto,
87  *   but then determines that they are either noise, or transmissions
88  *   from a distant wireless network (also "noise", really) that get
89  *   "stepped on" by stronger transmissions within our own network.
90  * This algorithm attempts to set a sensitivity level that is high
91  *   enough to receive all of our own network traffic, but not so
92  *   high that our DSP gets too busy trying to lock onto non-network
93  *   activity/noise. */
94 static int
95 il4965_sens_energy_cck(struct il_priv *il, u32 norm_fa, u32 rx_enable_time,
96 		       struct stats_general_data *rx_info)
97 {
98 	u32 max_nrg_cck = 0;
99 	int i = 0;
100 	u8 max_silence_rssi = 0;
101 	u32 silence_ref = 0;
102 	u8 silence_rssi_a = 0;
103 	u8 silence_rssi_b = 0;
104 	u8 silence_rssi_c = 0;
105 	u32 val;
106 
107 	/* "false_alarms" values below are cross-multiplications to assess the
108 	 *   numbers of false alarms within the measured period of actual Rx
109 	 *   (Rx is off when we're txing), vs the min/max expected false alarms
110 	 *   (some should be expected if rx is sensitive enough) in a
111 	 *   hypothetical listening period of 200 time units (TU), 204.8 msec:
112 	 *
113 	 * MIN_FA/fixed-time < false_alarms/actual-rx-time < MAX_FA/beacon-time
114 	 *
115 	 * */
116 	u32 false_alarms = norm_fa * 200 * 1024;
117 	u32 max_false_alarms = MAX_FA_CCK * rx_enable_time;
118 	u32 min_false_alarms = MIN_FA_CCK * rx_enable_time;
119 	struct il_sensitivity_data *data = NULL;
120 	const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
121 
122 	data = &(il->sensitivity_data);
123 
124 	data->nrg_auto_corr_silence_diff = 0;
125 
126 	/* Find max silence rssi among all 3 receivers.
127 	 * This is background noise, which may include transmissions from other
128 	 *    networks, measured during silence before our network's beacon */
129 	silence_rssi_a =
130 	    (u8) ((rx_info->beacon_silence_rssi_a & ALL_BAND_FILTER) >> 8);
131 	silence_rssi_b =
132 	    (u8) ((rx_info->beacon_silence_rssi_b & ALL_BAND_FILTER) >> 8);
133 	silence_rssi_c =
134 	    (u8) ((rx_info->beacon_silence_rssi_c & ALL_BAND_FILTER) >> 8);
135 
136 	val = max(silence_rssi_b, silence_rssi_c);
137 	max_silence_rssi = max(silence_rssi_a, (u8) val);
138 
139 	/* Store silence rssi in 20-beacon history table */
140 	data->nrg_silence_rssi[data->nrg_silence_idx] = max_silence_rssi;
141 	data->nrg_silence_idx++;
142 	if (data->nrg_silence_idx >= NRG_NUM_PREV_STAT_L)
143 		data->nrg_silence_idx = 0;
144 
145 	/* Find max silence rssi across 20 beacon history */
146 	for (i = 0; i < NRG_NUM_PREV_STAT_L; i++) {
147 		val = data->nrg_silence_rssi[i];
148 		silence_ref = max(silence_ref, val);
149 	}
150 	D_CALIB("silence a %u, b %u, c %u, 20-bcn max %u\n", silence_rssi_a,
151 		silence_rssi_b, silence_rssi_c, silence_ref);
152 
153 	/* Find max rx energy (min value!) among all 3 receivers,
154 	 *   measured during beacon frame.
155 	 * Save it in 10-beacon history table. */
156 	i = data->nrg_energy_idx;
157 	val = min(rx_info->beacon_energy_b, rx_info->beacon_energy_c);
158 	data->nrg_value[i] = min(rx_info->beacon_energy_a, val);
159 
160 	data->nrg_energy_idx++;
161 	if (data->nrg_energy_idx >= 10)
162 		data->nrg_energy_idx = 0;
163 
164 	/* Find min rx energy (max value) across 10 beacon history.
165 	 * This is the minimum signal level that we want to receive well.
166 	 * Add backoff (margin so we don't miss slightly lower energy frames).
167 	 * This establishes an upper bound (min value) for energy threshold. */
168 	max_nrg_cck = data->nrg_value[0];
169 	for (i = 1; i < 10; i++)
170 		max_nrg_cck = (u32) max(max_nrg_cck, (data->nrg_value[i]));
171 	max_nrg_cck += 6;
172 
173 	D_CALIB("rx energy a %u, b %u, c %u, 10-bcn max/min %u\n",
174 		rx_info->beacon_energy_a, rx_info->beacon_energy_b,
175 		rx_info->beacon_energy_c, max_nrg_cck - 6);
176 
177 	/* Count number of consecutive beacons with fewer-than-desired
178 	 *   false alarms. */
179 	if (false_alarms < min_false_alarms)
180 		data->num_in_cck_no_fa++;
181 	else
182 		data->num_in_cck_no_fa = 0;
183 	D_CALIB("consecutive bcns with few false alarms = %u\n",
184 		data->num_in_cck_no_fa);
185 
186 	/* If we got too many false alarms this time, reduce sensitivity */
187 	if (false_alarms > max_false_alarms &&
188 	    data->auto_corr_cck > AUTO_CORR_MAX_TH_CCK) {
189 		D_CALIB("norm FA %u > max FA %u\n", false_alarms,
190 			max_false_alarms);
191 		D_CALIB("... reducing sensitivity\n");
192 		data->nrg_curr_state = IL_FA_TOO_MANY;
193 		/* Store for "fewer than desired" on later beacon */
194 		data->nrg_silence_ref = silence_ref;
195 
196 		/* increase energy threshold (reduce nrg value)
197 		 *   to decrease sensitivity */
198 		data->nrg_th_cck = data->nrg_th_cck - NRG_STEP_CCK;
199 		/* Else if we got fewer than desired, increase sensitivity */
200 	} else if (false_alarms < min_false_alarms) {
201 		data->nrg_curr_state = IL_FA_TOO_FEW;
202 
203 		/* Compare silence level with silence level for most recent
204 		 *   healthy number or too many false alarms */
205 		data->nrg_auto_corr_silence_diff =
206 		    (s32) data->nrg_silence_ref - (s32) silence_ref;
207 
208 		D_CALIB("norm FA %u < min FA %u, silence diff %d\n",
209 			false_alarms, min_false_alarms,
210 			data->nrg_auto_corr_silence_diff);
211 
212 		/* Increase value to increase sensitivity, but only if:
213 		 * 1a) previous beacon did *not* have *too many* false alarms
214 		 * 1b) AND there's a significant difference in Rx levels
215 		 *      from a previous beacon with too many, or healthy # FAs
216 		 * OR 2) We've seen a lot of beacons (100) with too few
217 		 *       false alarms */
218 		if (data->nrg_prev_state != IL_FA_TOO_MANY &&
219 		    (data->nrg_auto_corr_silence_diff > NRG_DIFF ||
220 		     data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA)) {
221 
222 			D_CALIB("... increasing sensitivity\n");
223 			/* Increase nrg value to increase sensitivity */
224 			val = data->nrg_th_cck + NRG_STEP_CCK;
225 			data->nrg_th_cck = min((u32) ranges->min_nrg_cck, val);
226 		} else {
227 			D_CALIB("... but not changing sensitivity\n");
228 		}
229 
230 		/* Else we got a healthy number of false alarms, keep status quo */
231 	} else {
232 		D_CALIB(" FA in safe zone\n");
233 		data->nrg_curr_state = IL_FA_GOOD_RANGE;
234 
235 		/* Store for use in "fewer than desired" with later beacon */
236 		data->nrg_silence_ref = silence_ref;
237 
238 		/* If previous beacon had too many false alarms,
239 		 *   give it some extra margin by reducing sensitivity again
240 		 *   (but don't go below measured energy of desired Rx) */
241 		if (IL_FA_TOO_MANY == data->nrg_prev_state) {
242 			D_CALIB("... increasing margin\n");
243 			if (data->nrg_th_cck > (max_nrg_cck + NRG_MARGIN))
244 				data->nrg_th_cck -= NRG_MARGIN;
245 			else
246 				data->nrg_th_cck = max_nrg_cck;
247 		}
248 	}
249 
250 	/* Make sure the energy threshold does not go above the measured
251 	 * energy of the desired Rx signals (reduced by backoff margin),
252 	 * or else we might start missing Rx frames.
253 	 * Lower value is higher energy, so we use max()!
254 	 */
255 	data->nrg_th_cck = max(max_nrg_cck, data->nrg_th_cck);
256 	D_CALIB("new nrg_th_cck %u\n", data->nrg_th_cck);
257 
258 	data->nrg_prev_state = data->nrg_curr_state;
259 
260 	/* Auto-correlation CCK algorithm */
261 	if (false_alarms > min_false_alarms) {
262 
263 		/* increase auto_corr values to decrease sensitivity
264 		 * so the DSP won't be disturbed by the noise
265 		 */
266 		if (data->auto_corr_cck < AUTO_CORR_MAX_TH_CCK)
267 			data->auto_corr_cck = AUTO_CORR_MAX_TH_CCK + 1;
268 		else {
269 			val = data->auto_corr_cck + AUTO_CORR_STEP_CCK;
270 			data->auto_corr_cck =
271 			    min((u32) ranges->auto_corr_max_cck, val);
272 		}
273 		val = data->auto_corr_cck_mrc + AUTO_CORR_STEP_CCK;
274 		data->auto_corr_cck_mrc =
275 		    min((u32) ranges->auto_corr_max_cck_mrc, val);
276 	} else if (false_alarms < min_false_alarms &&
277 		   (data->nrg_auto_corr_silence_diff > NRG_DIFF ||
278 		    data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA)) {
279 
280 		/* Decrease auto_corr values to increase sensitivity */
281 		val = data->auto_corr_cck - AUTO_CORR_STEP_CCK;
282 		data->auto_corr_cck = max((u32) ranges->auto_corr_min_cck, val);
283 		val = data->auto_corr_cck_mrc - AUTO_CORR_STEP_CCK;
284 		data->auto_corr_cck_mrc =
285 		    max((u32) ranges->auto_corr_min_cck_mrc, val);
286 	}
287 
288 	return 0;
289 }
290 
291 static int
292 il4965_sens_auto_corr_ofdm(struct il_priv *il, u32 norm_fa, u32 rx_enable_time)
293 {
294 	u32 val;
295 	u32 false_alarms = norm_fa * 200 * 1024;
296 	u32 max_false_alarms = MAX_FA_OFDM * rx_enable_time;
297 	u32 min_false_alarms = MIN_FA_OFDM * rx_enable_time;
298 	struct il_sensitivity_data *data = NULL;
299 	const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
300 
301 	data = &(il->sensitivity_data);
302 
303 	/* If we got too many false alarms this time, reduce sensitivity */
304 	if (false_alarms > max_false_alarms) {
305 
306 		D_CALIB("norm FA %u > max FA %u)\n", false_alarms,
307 			max_false_alarms);
308 
309 		val = data->auto_corr_ofdm + AUTO_CORR_STEP_OFDM;
310 		data->auto_corr_ofdm =
311 		    min((u32) ranges->auto_corr_max_ofdm, val);
312 
313 		val = data->auto_corr_ofdm_mrc + AUTO_CORR_STEP_OFDM;
314 		data->auto_corr_ofdm_mrc =
315 		    min((u32) ranges->auto_corr_max_ofdm_mrc, val);
316 
317 		val = data->auto_corr_ofdm_x1 + AUTO_CORR_STEP_OFDM;
318 		data->auto_corr_ofdm_x1 =
319 		    min((u32) ranges->auto_corr_max_ofdm_x1, val);
320 
321 		val = data->auto_corr_ofdm_mrc_x1 + AUTO_CORR_STEP_OFDM;
322 		data->auto_corr_ofdm_mrc_x1 =
323 		    min((u32) ranges->auto_corr_max_ofdm_mrc_x1, val);
324 	}
325 
326 	/* Else if we got fewer than desired, increase sensitivity */
327 	else if (false_alarms < min_false_alarms) {
328 
329 		D_CALIB("norm FA %u < min FA %u\n", false_alarms,
330 			min_false_alarms);
331 
332 		val = data->auto_corr_ofdm - AUTO_CORR_STEP_OFDM;
333 		data->auto_corr_ofdm =
334 		    max((u32) ranges->auto_corr_min_ofdm, val);
335 
336 		val = data->auto_corr_ofdm_mrc - AUTO_CORR_STEP_OFDM;
337 		data->auto_corr_ofdm_mrc =
338 		    max((u32) ranges->auto_corr_min_ofdm_mrc, val);
339 
340 		val = data->auto_corr_ofdm_x1 - AUTO_CORR_STEP_OFDM;
341 		data->auto_corr_ofdm_x1 =
342 		    max((u32) ranges->auto_corr_min_ofdm_x1, val);
343 
344 		val = data->auto_corr_ofdm_mrc_x1 - AUTO_CORR_STEP_OFDM;
345 		data->auto_corr_ofdm_mrc_x1 =
346 		    max((u32) ranges->auto_corr_min_ofdm_mrc_x1, val);
347 	} else {
348 		D_CALIB("min FA %u < norm FA %u < max FA %u OK\n",
349 			min_false_alarms, false_alarms, max_false_alarms);
350 	}
351 	return 0;
352 }
353 
354 static void
355 il4965_prepare_legacy_sensitivity_tbl(struct il_priv *il,
356 				      struct il_sensitivity_data *data,
357 				      __le16 *tbl)
358 {
359 	tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_IDX] =
360 	    cpu_to_le16((u16) data->auto_corr_ofdm);
361 	tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_MRC_IDX] =
362 	    cpu_to_le16((u16) data->auto_corr_ofdm_mrc);
363 	tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_IDX] =
364 	    cpu_to_le16((u16) data->auto_corr_ofdm_x1);
365 	tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_MRC_IDX] =
366 	    cpu_to_le16((u16) data->auto_corr_ofdm_mrc_x1);
367 
368 	tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_IDX] =
369 	    cpu_to_le16((u16) data->auto_corr_cck);
370 	tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_MRC_IDX] =
371 	    cpu_to_le16((u16) data->auto_corr_cck_mrc);
372 
373 	tbl[HD_MIN_ENERGY_CCK_DET_IDX] = cpu_to_le16((u16) data->nrg_th_cck);
374 	tbl[HD_MIN_ENERGY_OFDM_DET_IDX] = cpu_to_le16((u16) data->nrg_th_ofdm);
375 
376 	tbl[HD_BARKER_CORR_TH_ADD_MIN_IDX] =
377 	    cpu_to_le16(data->barker_corr_th_min);
378 	tbl[HD_BARKER_CORR_TH_ADD_MIN_MRC_IDX] =
379 	    cpu_to_le16(data->barker_corr_th_min_mrc);
380 	tbl[HD_OFDM_ENERGY_TH_IN_IDX] = cpu_to_le16(data->nrg_th_cca);
381 
382 	D_CALIB("ofdm: ac %u mrc %u x1 %u mrc_x1 %u thresh %u\n",
383 		data->auto_corr_ofdm, data->auto_corr_ofdm_mrc,
384 		data->auto_corr_ofdm_x1, data->auto_corr_ofdm_mrc_x1,
385 		data->nrg_th_ofdm);
386 
387 	D_CALIB("cck: ac %u mrc %u thresh %u\n", data->auto_corr_cck,
388 		data->auto_corr_cck_mrc, data->nrg_th_cck);
389 }
390 
391 /* Prepare a C_SENSITIVITY, send to uCode if values have changed */
392 static int
393 il4965_sensitivity_write(struct il_priv *il)
394 {
395 	struct il_sensitivity_cmd cmd;
396 	struct il_sensitivity_data *data = NULL;
397 	struct il_host_cmd cmd_out = {
398 		.id = C_SENSITIVITY,
399 		.len = sizeof(struct il_sensitivity_cmd),
400 		.flags = CMD_ASYNC,
401 		.data = &cmd,
402 	};
403 
404 	data = &(il->sensitivity_data);
405 
406 	memset(&cmd, 0, sizeof(cmd));
407 
408 	il4965_prepare_legacy_sensitivity_tbl(il, data, &cmd.table[0]);
409 
410 	/* Update uCode's "work" table, and copy it to DSP */
411 	cmd.control = C_SENSITIVITY_CONTROL_WORK_TBL;
412 
413 	/* Don't send command to uCode if nothing has changed */
414 	if (!memcmp
415 	    (&cmd.table[0], &(il->sensitivity_tbl[0]),
416 	     sizeof(u16) * HD_TBL_SIZE)) {
417 		D_CALIB("No change in C_SENSITIVITY\n");
418 		return 0;
419 	}
420 
421 	/* Copy table for comparison next time */
422 	memcpy(&(il->sensitivity_tbl[0]), &(cmd.table[0]),
423 	       sizeof(u16) * HD_TBL_SIZE);
424 
425 	return il_send_cmd(il, &cmd_out);
426 }
427 
428 void
429 il4965_init_sensitivity(struct il_priv *il)
430 {
431 	int ret = 0;
432 	int i;
433 	struct il_sensitivity_data *data = NULL;
434 	const struct il_sensitivity_ranges *ranges = il->hw_params.sens;
435 
436 	if (il->disable_sens_cal)
437 		return;
438 
439 	D_CALIB("Start il4965_init_sensitivity\n");
440 
441 	/* Clear driver's sensitivity algo data */
442 	data = &(il->sensitivity_data);
443 
444 	if (ranges == NULL)
445 		return;
446 
447 	memset(data, 0, sizeof(struct il_sensitivity_data));
448 
449 	data->num_in_cck_no_fa = 0;
450 	data->nrg_curr_state = IL_FA_TOO_MANY;
451 	data->nrg_prev_state = IL_FA_TOO_MANY;
452 	data->nrg_silence_ref = 0;
453 	data->nrg_silence_idx = 0;
454 	data->nrg_energy_idx = 0;
455 
456 	for (i = 0; i < 10; i++)
457 		data->nrg_value[i] = 0;
458 
459 	for (i = 0; i < NRG_NUM_PREV_STAT_L; i++)
460 		data->nrg_silence_rssi[i] = 0;
461 
462 	data->auto_corr_ofdm = ranges->auto_corr_min_ofdm;
463 	data->auto_corr_ofdm_mrc = ranges->auto_corr_min_ofdm_mrc;
464 	data->auto_corr_ofdm_x1 = ranges->auto_corr_min_ofdm_x1;
465 	data->auto_corr_ofdm_mrc_x1 = ranges->auto_corr_min_ofdm_mrc_x1;
466 	data->auto_corr_cck = AUTO_CORR_CCK_MIN_VAL_DEF;
467 	data->auto_corr_cck_mrc = ranges->auto_corr_min_cck_mrc;
468 	data->nrg_th_cck = ranges->nrg_th_cck;
469 	data->nrg_th_ofdm = ranges->nrg_th_ofdm;
470 	data->barker_corr_th_min = ranges->barker_corr_th_min;
471 	data->barker_corr_th_min_mrc = ranges->barker_corr_th_min_mrc;
472 	data->nrg_th_cca = ranges->nrg_th_cca;
473 
474 	data->last_bad_plcp_cnt_ofdm = 0;
475 	data->last_fa_cnt_ofdm = 0;
476 	data->last_bad_plcp_cnt_cck = 0;
477 	data->last_fa_cnt_cck = 0;
478 
479 	ret |= il4965_sensitivity_write(il);
480 	D_CALIB("<<return 0x%X\n", ret);
481 }
482 
483 void
484 il4965_sensitivity_calibration(struct il_priv *il, void *resp)
485 {
486 	u32 rx_enable_time;
487 	u32 fa_cck;
488 	u32 fa_ofdm;
489 	u32 bad_plcp_cck;
490 	u32 bad_plcp_ofdm;
491 	u32 norm_fa_ofdm;
492 	u32 norm_fa_cck;
493 	struct il_sensitivity_data *data = NULL;
494 	struct stats_rx_non_phy *rx_info;
495 	struct stats_rx_phy *ofdm, *cck;
496 	unsigned long flags;
497 	struct stats_general_data statis;
498 
499 	if (il->disable_sens_cal)
500 		return;
501 
502 	data = &(il->sensitivity_data);
503 
504 	if (!il_is_any_associated(il)) {
505 		D_CALIB("<< - not associated\n");
506 		return;
507 	}
508 
509 	spin_lock_irqsave(&il->lock, flags);
510 
511 	rx_info = &(((struct il_notif_stats *)resp)->rx.general);
512 	ofdm = &(((struct il_notif_stats *)resp)->rx.ofdm);
513 	cck = &(((struct il_notif_stats *)resp)->rx.cck);
514 
515 	if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
516 		D_CALIB("<< invalid data.\n");
517 		spin_unlock_irqrestore(&il->lock, flags);
518 		return;
519 	}
520 
521 	/* Extract Statistics: */
522 	rx_enable_time = le32_to_cpu(rx_info->channel_load);
523 	fa_cck = le32_to_cpu(cck->false_alarm_cnt);
524 	fa_ofdm = le32_to_cpu(ofdm->false_alarm_cnt);
525 	bad_plcp_cck = le32_to_cpu(cck->plcp_err);
526 	bad_plcp_ofdm = le32_to_cpu(ofdm->plcp_err);
527 
528 	statis.beacon_silence_rssi_a =
529 	    le32_to_cpu(rx_info->beacon_silence_rssi_a);
530 	statis.beacon_silence_rssi_b =
531 	    le32_to_cpu(rx_info->beacon_silence_rssi_b);
532 	statis.beacon_silence_rssi_c =
533 	    le32_to_cpu(rx_info->beacon_silence_rssi_c);
534 	statis.beacon_energy_a = le32_to_cpu(rx_info->beacon_energy_a);
535 	statis.beacon_energy_b = le32_to_cpu(rx_info->beacon_energy_b);
536 	statis.beacon_energy_c = le32_to_cpu(rx_info->beacon_energy_c);
537 
538 	spin_unlock_irqrestore(&il->lock, flags);
539 
540 	D_CALIB("rx_enable_time = %u usecs\n", rx_enable_time);
541 
542 	if (!rx_enable_time) {
543 		D_CALIB("<< RX Enable Time == 0!\n");
544 		return;
545 	}
546 
547 	/* These stats increase monotonically, and do not reset
548 	 *   at each beacon.  Calculate difference from last value, or just
549 	 *   use the new stats value if it has reset or wrapped around. */
550 	if (data->last_bad_plcp_cnt_cck > bad_plcp_cck)
551 		data->last_bad_plcp_cnt_cck = bad_plcp_cck;
552 	else {
553 		bad_plcp_cck -= data->last_bad_plcp_cnt_cck;
554 		data->last_bad_plcp_cnt_cck += bad_plcp_cck;
555 	}
556 
557 	if (data->last_bad_plcp_cnt_ofdm > bad_plcp_ofdm)
558 		data->last_bad_plcp_cnt_ofdm = bad_plcp_ofdm;
559 	else {
560 		bad_plcp_ofdm -= data->last_bad_plcp_cnt_ofdm;
561 		data->last_bad_plcp_cnt_ofdm += bad_plcp_ofdm;
562 	}
563 
564 	if (data->last_fa_cnt_ofdm > fa_ofdm)
565 		data->last_fa_cnt_ofdm = fa_ofdm;
566 	else {
567 		fa_ofdm -= data->last_fa_cnt_ofdm;
568 		data->last_fa_cnt_ofdm += fa_ofdm;
569 	}
570 
571 	if (data->last_fa_cnt_cck > fa_cck)
572 		data->last_fa_cnt_cck = fa_cck;
573 	else {
574 		fa_cck -= data->last_fa_cnt_cck;
575 		data->last_fa_cnt_cck += fa_cck;
576 	}
577 
578 	/* Total aborted signal locks */
579 	norm_fa_ofdm = fa_ofdm + bad_plcp_ofdm;
580 	norm_fa_cck = fa_cck + bad_plcp_cck;
581 
582 	D_CALIB("cck: fa %u badp %u  ofdm: fa %u badp %u\n", fa_cck,
583 		bad_plcp_cck, fa_ofdm, bad_plcp_ofdm);
584 
585 	il4965_sens_auto_corr_ofdm(il, norm_fa_ofdm, rx_enable_time);
586 	il4965_sens_energy_cck(il, norm_fa_cck, rx_enable_time, &statis);
587 
588 	il4965_sensitivity_write(il);
589 }
590 
591 static inline u8
592 il4965_find_first_chain(u8 mask)
593 {
594 	if (mask & ANT_A)
595 		return CHAIN_A;
596 	if (mask & ANT_B)
597 		return CHAIN_B;
598 	return CHAIN_C;
599 }
600 
601 /*
602  * Run disconnected antenna algorithm to find out which antennas are
603  * disconnected.
604  */
605 static void
606 il4965_find_disconn_antenna(struct il_priv *il, u32 * average_sig,
607 			    struct il_chain_noise_data *data)
608 {
609 	u32 active_chains = 0;
610 	u32 max_average_sig;
611 	u16 max_average_sig_antenna_i;
612 	u8 num_tx_chains;
613 	u8 first_chain;
614 	u16 i = 0;
615 
616 	average_sig[0] =
617 	    data->chain_signal_a /
618 	    il->cfg->chain_noise_num_beacons;
619 	average_sig[1] =
620 	    data->chain_signal_b /
621 	    il->cfg->chain_noise_num_beacons;
622 	average_sig[2] =
623 	    data->chain_signal_c /
624 	    il->cfg->chain_noise_num_beacons;
625 
626 	if (average_sig[0] >= average_sig[1]) {
627 		max_average_sig = average_sig[0];
628 		max_average_sig_antenna_i = 0;
629 		active_chains = (1 << max_average_sig_antenna_i);
630 	} else {
631 		max_average_sig = average_sig[1];
632 		max_average_sig_antenna_i = 1;
633 		active_chains = (1 << max_average_sig_antenna_i);
634 	}
635 
636 	if (average_sig[2] >= max_average_sig) {
637 		max_average_sig = average_sig[2];
638 		max_average_sig_antenna_i = 2;
639 		active_chains = (1 << max_average_sig_antenna_i);
640 	}
641 
642 	D_CALIB("average_sig: a %d b %d c %d\n", average_sig[0], average_sig[1],
643 		average_sig[2]);
644 	D_CALIB("max_average_sig = %d, antenna %d\n", max_average_sig,
645 		max_average_sig_antenna_i);
646 
647 	/* Compare signal strengths for all 3 receivers. */
648 	for (i = 0; i < NUM_RX_CHAINS; i++) {
649 		if (i != max_average_sig_antenna_i) {
650 			s32 rssi_delta = (max_average_sig - average_sig[i]);
651 
652 			/* If signal is very weak, compared with
653 			 * strongest, mark it as disconnected. */
654 			if (rssi_delta > MAXIMUM_ALLOWED_PATHLOSS)
655 				data->disconn_array[i] = 1;
656 			else
657 				active_chains |= (1 << i);
658 			D_CALIB("i = %d  rssiDelta = %d  "
659 				"disconn_array[i] = %d\n", i, rssi_delta,
660 				data->disconn_array[i]);
661 		}
662 	}
663 
664 	/*
665 	 * The above algorithm sometimes fails when the ucode
666 	 * reports 0 for all chains. It's not clear why that
667 	 * happens to start with, but it is then causing trouble
668 	 * because this can make us enable more chains than the
669 	 * hardware really has.
670 	 *
671 	 * To be safe, simply mask out any chains that we know
672 	 * are not on the device.
673 	 */
674 	active_chains &= il->hw_params.valid_rx_ant;
675 
676 	num_tx_chains = 0;
677 	for (i = 0; i < NUM_RX_CHAINS; i++) {
678 		/* loops on all the bits of
679 		 * il->hw_setting.valid_tx_ant */
680 		u8 ant_msk = (1 << i);
681 		if (!(il->hw_params.valid_tx_ant & ant_msk))
682 			continue;
683 
684 		num_tx_chains++;
685 		if (data->disconn_array[i] == 0)
686 			/* there is a Tx antenna connected */
687 			break;
688 		if (num_tx_chains == il->hw_params.tx_chains_num &&
689 		    data->disconn_array[i]) {
690 			/*
691 			 * If all chains are disconnected
692 			 * connect the first valid tx chain
693 			 */
694 			first_chain =
695 			    il4965_find_first_chain(il->cfg->valid_tx_ant);
696 			data->disconn_array[first_chain] = 0;
697 			active_chains |= BIT(first_chain);
698 			D_CALIB("All Tx chains are disconnected"
699 				"- declare %d as connected\n", first_chain);
700 			break;
701 		}
702 	}
703 
704 	if (active_chains != il->hw_params.valid_rx_ant &&
705 	    active_chains != il->chain_noise_data.active_chains)
706 		D_CALIB("Detected that not all antennas are connected! "
707 			"Connected: %#x, valid: %#x.\n", active_chains,
708 			il->hw_params.valid_rx_ant);
709 
710 	/* Save for use within RXON, TX, SCAN commands, etc. */
711 	data->active_chains = active_chains;
712 	D_CALIB("active_chains (bitwise) = 0x%x\n", active_chains);
713 }
714 
715 static void
716 il4965_gain_computation(struct il_priv *il, u32 * average_noise,
717 			u16 min_average_noise_antenna_i, u32 min_average_noise,
718 			u8 default_chain)
719 {
720 	int i, ret;
721 	struct il_chain_noise_data *data = &il->chain_noise_data;
722 
723 	data->delta_gain_code[min_average_noise_antenna_i] = 0;
724 
725 	for (i = default_chain; i < NUM_RX_CHAINS; i++) {
726 		s32 delta_g = 0;
727 
728 		if (!data->disconn_array[i] &&
729 		    data->delta_gain_code[i] ==
730 		    CHAIN_NOISE_DELTA_GAIN_INIT_VAL) {
731 			delta_g = average_noise[i] - min_average_noise;
732 			data->delta_gain_code[i] = (u8) ((delta_g * 10) / 15);
733 			data->delta_gain_code[i] =
734 			    min(data->delta_gain_code[i],
735 				(u8) CHAIN_NOISE_MAX_DELTA_GAIN_CODE);
736 
737 			data->delta_gain_code[i] =
738 			    (data->delta_gain_code[i] | (1 << 2));
739 		} else {
740 			data->delta_gain_code[i] = 0;
741 		}
742 	}
743 	D_CALIB("delta_gain_codes: a %d b %d c %d\n", data->delta_gain_code[0],
744 		data->delta_gain_code[1], data->delta_gain_code[2]);
745 
746 	/* Differential gain gets sent to uCode only once */
747 	if (!data->radio_write) {
748 		struct il_calib_diff_gain_cmd cmd;
749 		data->radio_write = 1;
750 
751 		memset(&cmd, 0, sizeof(cmd));
752 		cmd.hdr.op_code = IL_PHY_CALIBRATE_DIFF_GAIN_CMD;
753 		cmd.diff_gain_a = data->delta_gain_code[0];
754 		cmd.diff_gain_b = data->delta_gain_code[1];
755 		cmd.diff_gain_c = data->delta_gain_code[2];
756 		ret = il_send_cmd_pdu(il, C_PHY_CALIBRATION, sizeof(cmd), &cmd);
757 		if (ret)
758 			D_CALIB("fail sending cmd " "C_PHY_CALIBRATION\n");
759 
760 		/* TODO we might want recalculate
761 		 * rx_chain in rxon cmd */
762 
763 		/* Mark so we run this algo only once! */
764 		data->state = IL_CHAIN_NOISE_CALIBRATED;
765 	}
766 }
767 
768 /*
769  * Accumulate 16 beacons of signal and noise stats for each of
770  *   3 receivers/antennas/rx-chains, then figure out:
771  * 1)  Which antennas are connected.
772  * 2)  Differential rx gain settings to balance the 3 receivers.
773  */
774 void
775 il4965_chain_noise_calibration(struct il_priv *il, void *stat_resp)
776 {
777 	struct il_chain_noise_data *data = NULL;
778 
779 	u32 chain_noise_a;
780 	u32 chain_noise_b;
781 	u32 chain_noise_c;
782 	u32 chain_sig_a;
783 	u32 chain_sig_b;
784 	u32 chain_sig_c;
785 	u32 average_sig[NUM_RX_CHAINS] = { INITIALIZATION_VALUE };
786 	u32 average_noise[NUM_RX_CHAINS] = { INITIALIZATION_VALUE };
787 	u32 min_average_noise = MIN_AVERAGE_NOISE_MAX_VALUE;
788 	u16 min_average_noise_antenna_i = INITIALIZATION_VALUE;
789 	u16 i = 0;
790 	u16 rxon_chnum = INITIALIZATION_VALUE;
791 	u16 stat_chnum = INITIALIZATION_VALUE;
792 	u8 rxon_band24;
793 	u8 stat_band24;
794 	unsigned long flags;
795 	struct stats_rx_non_phy *rx_info;
796 
797 	if (il->disable_chain_noise_cal)
798 		return;
799 
800 	data = &(il->chain_noise_data);
801 
802 	/*
803 	 * Accumulate just the first "chain_noise_num_beacons" after
804 	 * the first association, then we're done forever.
805 	 */
806 	if (data->state != IL_CHAIN_NOISE_ACCUMULATE) {
807 		if (data->state == IL_CHAIN_NOISE_ALIVE)
808 			D_CALIB("Wait for noise calib reset\n");
809 		return;
810 	}
811 
812 	spin_lock_irqsave(&il->lock, flags);
813 
814 	rx_info = &(((struct il_notif_stats *)stat_resp)->rx.general);
815 
816 	if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
817 		D_CALIB(" << Interference data unavailable\n");
818 		spin_unlock_irqrestore(&il->lock, flags);
819 		return;
820 	}
821 
822 	rxon_band24 = !!(il->staging.flags & RXON_FLG_BAND_24G_MSK);
823 	rxon_chnum = le16_to_cpu(il->staging.channel);
824 
825 	stat_band24 =
826 	    !!(((struct il_notif_stats *)stat_resp)->
827 	       flag & STATS_REPLY_FLG_BAND_24G_MSK);
828 	stat_chnum =
829 	    le32_to_cpu(((struct il_notif_stats *)stat_resp)->flag) >> 16;
830 
831 	/* Make sure we accumulate data for just the associated channel
832 	 *   (even if scanning). */
833 	if (rxon_chnum != stat_chnum || rxon_band24 != stat_band24) {
834 		D_CALIB("Stats not from chan=%d, band24=%d\n", rxon_chnum,
835 			rxon_band24);
836 		spin_unlock_irqrestore(&il->lock, flags);
837 		return;
838 	}
839 
840 	/*
841 	 *  Accumulate beacon stats values across
842 	 * "chain_noise_num_beacons"
843 	 */
844 	chain_noise_a =
845 	    le32_to_cpu(rx_info->beacon_silence_rssi_a) & IN_BAND_FILTER;
846 	chain_noise_b =
847 	    le32_to_cpu(rx_info->beacon_silence_rssi_b) & IN_BAND_FILTER;
848 	chain_noise_c =
849 	    le32_to_cpu(rx_info->beacon_silence_rssi_c) & IN_BAND_FILTER;
850 
851 	chain_sig_a = le32_to_cpu(rx_info->beacon_rssi_a) & IN_BAND_FILTER;
852 	chain_sig_b = le32_to_cpu(rx_info->beacon_rssi_b) & IN_BAND_FILTER;
853 	chain_sig_c = le32_to_cpu(rx_info->beacon_rssi_c) & IN_BAND_FILTER;
854 
855 	spin_unlock_irqrestore(&il->lock, flags);
856 
857 	data->beacon_count++;
858 
859 	data->chain_noise_a = (chain_noise_a + data->chain_noise_a);
860 	data->chain_noise_b = (chain_noise_b + data->chain_noise_b);
861 	data->chain_noise_c = (chain_noise_c + data->chain_noise_c);
862 
863 	data->chain_signal_a = (chain_sig_a + data->chain_signal_a);
864 	data->chain_signal_b = (chain_sig_b + data->chain_signal_b);
865 	data->chain_signal_c = (chain_sig_c + data->chain_signal_c);
866 
867 	D_CALIB("chan=%d, band24=%d, beacon=%d\n", rxon_chnum, rxon_band24,
868 		data->beacon_count);
869 	D_CALIB("chain_sig: a %d b %d c %d\n", chain_sig_a, chain_sig_b,
870 		chain_sig_c);
871 	D_CALIB("chain_noise: a %d b %d c %d\n", chain_noise_a, chain_noise_b,
872 		chain_noise_c);
873 
874 	/* If this is the "chain_noise_num_beacons", determine:
875 	 * 1)  Disconnected antennas (using signal strengths)
876 	 * 2)  Differential gain (using silence noise) to balance receivers */
877 	if (data->beacon_count != il->cfg->chain_noise_num_beacons)
878 		return;
879 
880 	/* Analyze signal for disconnected antenna */
881 	il4965_find_disconn_antenna(il, average_sig, data);
882 
883 	/* Analyze noise for rx balance */
884 	average_noise[0] =
885 	    data->chain_noise_a / il->cfg->chain_noise_num_beacons;
886 	average_noise[1] =
887 	    data->chain_noise_b / il->cfg->chain_noise_num_beacons;
888 	average_noise[2] =
889 	    data->chain_noise_c / il->cfg->chain_noise_num_beacons;
890 
891 	for (i = 0; i < NUM_RX_CHAINS; i++) {
892 		if (!data->disconn_array[i] &&
893 		    average_noise[i] <= min_average_noise) {
894 			/* This means that chain i is active and has
895 			 * lower noise values so far: */
896 			min_average_noise = average_noise[i];
897 			min_average_noise_antenna_i = i;
898 		}
899 	}
900 
901 	D_CALIB("average_noise: a %d b %d c %d\n", average_noise[0],
902 		average_noise[1], average_noise[2]);
903 
904 	D_CALIB("min_average_noise = %d, antenna %d\n", min_average_noise,
905 		min_average_noise_antenna_i);
906 
907 	il4965_gain_computation(il, average_noise, min_average_noise_antenna_i,
908 				min_average_noise,
909 				il4965_find_first_chain(il->cfg->valid_rx_ant));
910 
911 	/* Some power changes may have been made during the calibration.
912 	 * Update and commit the RXON
913 	 */
914 	if (il->ops->update_chain_flags)
915 		il->ops->update_chain_flags(il);
916 
917 	data->state = IL_CHAIN_NOISE_DONE;
918 	il_power_update_mode(il, false);
919 }
920 
921 void
922 il4965_reset_run_time_calib(struct il_priv *il)
923 {
924 	int i;
925 	memset(&(il->sensitivity_data), 0, sizeof(struct il_sensitivity_data));
926 	memset(&(il->chain_noise_data), 0, sizeof(struct il_chain_noise_data));
927 	for (i = 0; i < NUM_RX_CHAINS; i++)
928 		il->chain_noise_data.delta_gain_code[i] =
929 		    CHAIN_NOISE_DELTA_GAIN_INIT_VAL;
930 
931 	/* Ask for stats now, the uCode will send notification
932 	 * periodically after association */
933 	il_send_stats_request(il, CMD_ASYNC, true);
934 }
935