1/******************************************************************************
2 *
3 * This file is provided under a dual BSD/GPLv2 license.  When using or
4 * redistributing this file, you may do so under either license.
5 *
6 * GPL LICENSE SUMMARY
7 *
8 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
22 * USA
23 *
24 * The full GNU General Public License is included in this distribution
25 * in the file called LICENSE.GPL.
26 *
27 * Contact Information:
28 *  Intel Linux Wireless <ilw@linux.intel.com>
29 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
30 *
31 * BSD LICENSE
32 *
33 * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 *
40 *  * Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 *  * Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in
44 *    the documentation and/or other materials provided with the
45 *    distribution.
46 *  * Neither the name Intel Corporation nor the names of its
47 *    contributors may be used to endorse or promote products derived
48 *    from this software without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
51 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
52 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
53 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
54 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
55 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
56 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
57 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
58 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
60 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 *****************************************************************************/
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
73struct 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. */
94static int
95il4965_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
291static int
292il4965_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
354static void
355il4965_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 */
392static int
393il4965_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
428void
429il4965_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
483void
484il4965_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
591static inline u8
592il4965_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 */
605static void
606il4965_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
715static void
716il4965_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 */
774void
775il4965_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
921void
922il4965_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