1/*
2 * Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
3 * Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
4 * Copyright (c) 2007-2008 Matthew W. S. Bell <mentor@madwifi.org>
5 * Copyright (c) 2007-2008 Luis Rodriguez <mcgrof@winlab.rutgers.edu>
6 * Copyright (c) 2007-2008 Pavel Roskin <proski@gnu.org>
7 * Copyright (c) 2007-2008 Jiri Slaby <jirislaby@gmail.com>
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 *
21 */
22
23/*********************************\
24* Protocol Control Unit Functions *
25\*********************************/
26
27#include <asm/unaligned.h>
28
29#include "ath5k.h"
30#include "reg.h"
31#include "debug.h"
32
33/**
34 * DOC: Protocol Control Unit (PCU) functions
35 *
36 * Protocol control unit is responsible to maintain various protocol
37 * properties before a frame is send and after a frame is received to/from
38 * baseband. To be more specific, PCU handles:
39 *
40 * - Buffering of RX and TX frames (after QCU/DCUs)
41 *
42 * - Encrypting and decrypting (using the built-in engine)
43 *
44 * - Generating ACKs, RTS/CTS frames
45 *
46 * - Maintaining TSF
47 *
48 * - FCS
49 *
50 * - Updating beacon data (with TSF etc)
51 *
52 * - Generating virtual CCA
53 *
54 * - RX/Multicast filtering
55 *
56 * - BSSID filtering
57 *
58 * - Various statistics
59 *
60 * -Different operating modes: AP, STA, IBSS
61 *
62 * Note: Most of these functions can be tweaked/bypassed so you can do
63 * them on sw above for debugging or research. For more infos check out PCU
64 * registers on reg.h.
65 */
66
67/**
68 * DOC: ACK rates
69 *
70 * AR5212+ can use higher rates for ack transmission
71 * based on current tx rate instead of the base rate.
72 * It does this to better utilize channel usage.
73 * There is a mapping between G rates (that cover both
74 * CCK and OFDM) and ack rates that we use when setting
75 * rate -> duration table. This mapping is hw-based so
76 * don't change anything.
77 *
78 * To enable this functionality we must set
79 * ah->ah_ack_bitrate_high to true else base rate is
80 * used (1Mb for CCK, 6Mb for OFDM).
81 */
82static const unsigned int ack_rates_high[] =
83/* Tx -> ACK */
84/* 1Mb -> 1Mb */ { 0,
85/* 2MB -> 2Mb */ 1,
86/* 5.5Mb -> 2Mb */ 1,
87/* 11Mb -> 2Mb */ 1,
88/* 6Mb -> 6Mb */ 4,
89/* 9Mb -> 6Mb */ 4,
90/* 12Mb -> 12Mb */ 6,
91/* 18Mb -> 12Mb */ 6,
92/* 24Mb -> 24Mb */ 8,
93/* 36Mb -> 24Mb */ 8,
94/* 48Mb -> 24Mb */ 8,
95/* 54Mb -> 24Mb */ 8 };
96
97/*******************\
98* Helper functions *
99\*******************/
100
101/**
102 * ath5k_hw_get_frame_duration() - Get tx time of a frame
103 * @ah: The &struct ath5k_hw
104 * @band: One of enum nl80211_band
105 * @len: Frame's length in bytes
106 * @rate: The @struct ieee80211_rate
107 * @shortpre: Indicate short preample
108 *
109 * Calculate tx duration of a frame given it's rate and length
110 * It extends ieee80211_generic_frame_duration for non standard
111 * bwmodes.
112 */
113int
114ath5k_hw_get_frame_duration(struct ath5k_hw *ah, enum nl80211_band band,
115 int len, struct ieee80211_rate *rate, bool shortpre)
116{
117 int sifs, preamble, plcp_bits, sym_time;
118 int bitrate, bits, symbols, symbol_bits;
119 int dur;
120
121 /* Fallback */
122 if (!ah->ah_bwmode) {
123 __le16 raw_dur = ieee80211_generic_frame_duration(hw: ah->hw,
124 NULL, band, frame_len: len, rate);
125
126 /* subtract difference between long and short preamble */
127 dur = le16_to_cpu(raw_dur);
128 if (shortpre)
129 dur -= 96;
130
131 return dur;
132 }
133
134 bitrate = rate->bitrate;
135 preamble = AR5K_INIT_OFDM_PREAMPLE_TIME;
136 plcp_bits = AR5K_INIT_OFDM_PLCP_BITS;
137 sym_time = AR5K_INIT_OFDM_SYMBOL_TIME;
138
139 switch (ah->ah_bwmode) {
140 case AR5K_BWMODE_40MHZ:
141 sifs = AR5K_INIT_SIFS_TURBO;
142 preamble = AR5K_INIT_OFDM_PREAMBLE_TIME_MIN;
143 break;
144 case AR5K_BWMODE_10MHZ:
145 sifs = AR5K_INIT_SIFS_HALF_RATE;
146 preamble *= 2;
147 sym_time *= 2;
148 bitrate = DIV_ROUND_UP(bitrate, 2);
149 break;
150 case AR5K_BWMODE_5MHZ:
151 sifs = AR5K_INIT_SIFS_QUARTER_RATE;
152 preamble *= 4;
153 sym_time *= 4;
154 bitrate = DIV_ROUND_UP(bitrate, 4);
155 break;
156 default:
157 sifs = AR5K_INIT_SIFS_DEFAULT_BG;
158 break;
159 }
160
161 bits = plcp_bits + (len << 3);
162 /* Bit rate is in 100Kbits */
163 symbol_bits = bitrate * sym_time;
164 symbols = DIV_ROUND_UP(bits * 10, symbol_bits);
165
166 dur = sifs + preamble + (sym_time * symbols);
167
168 return dur;
169}
170
171/**
172 * ath5k_hw_get_default_slottime() - Get the default slot time for current mode
173 * @ah: The &struct ath5k_hw
174 */
175unsigned int
176ath5k_hw_get_default_slottime(struct ath5k_hw *ah)
177{
178 struct ieee80211_channel *channel = ah->ah_current_channel;
179 unsigned int slot_time;
180
181 switch (ah->ah_bwmode) {
182 case AR5K_BWMODE_40MHZ:
183 slot_time = AR5K_INIT_SLOT_TIME_TURBO;
184 break;
185 case AR5K_BWMODE_10MHZ:
186 slot_time = AR5K_INIT_SLOT_TIME_HALF_RATE;
187 break;
188 case AR5K_BWMODE_5MHZ:
189 slot_time = AR5K_INIT_SLOT_TIME_QUARTER_RATE;
190 break;
191 case AR5K_BWMODE_DEFAULT:
192 default:
193 slot_time = AR5K_INIT_SLOT_TIME_DEFAULT;
194 if ((channel->hw_value == AR5K_MODE_11B) && !ah->ah_short_slot)
195 slot_time = AR5K_INIT_SLOT_TIME_B;
196 break;
197 }
198
199 return slot_time;
200}
201
202/**
203 * ath5k_hw_get_default_sifs() - Get the default SIFS for current mode
204 * @ah: The &struct ath5k_hw
205 */
206unsigned int
207ath5k_hw_get_default_sifs(struct ath5k_hw *ah)
208{
209 struct ieee80211_channel *channel = ah->ah_current_channel;
210 unsigned int sifs;
211
212 switch (ah->ah_bwmode) {
213 case AR5K_BWMODE_40MHZ:
214 sifs = AR5K_INIT_SIFS_TURBO;
215 break;
216 case AR5K_BWMODE_10MHZ:
217 sifs = AR5K_INIT_SIFS_HALF_RATE;
218 break;
219 case AR5K_BWMODE_5MHZ:
220 sifs = AR5K_INIT_SIFS_QUARTER_RATE;
221 break;
222 case AR5K_BWMODE_DEFAULT:
223 default:
224 sifs = AR5K_INIT_SIFS_DEFAULT_BG;
225 if (channel->band == NL80211_BAND_5GHZ)
226 sifs = AR5K_INIT_SIFS_DEFAULT_A;
227 break;
228 }
229
230 return sifs;
231}
232
233/**
234 * ath5k_hw_update_mib_counters() - Update MIB counters (mac layer statistics)
235 * @ah: The &struct ath5k_hw
236 *
237 * Reads MIB counters from PCU and updates sw statistics. Is called after a
238 * MIB interrupt, because one of these counters might have reached their maximum
239 * and triggered the MIB interrupt, to let us read and clear the counter.
240 *
241 * NOTE: Is called in interrupt context!
242 */
243void
244ath5k_hw_update_mib_counters(struct ath5k_hw *ah)
245{
246 struct ath5k_statistics *stats = &ah->stats;
247
248 /* Read-And-Clear */
249 stats->ack_fail += ath5k_hw_reg_read(ah, AR5K_ACK_FAIL);
250 stats->rts_fail += ath5k_hw_reg_read(ah, AR5K_RTS_FAIL);
251 stats->rts_ok += ath5k_hw_reg_read(ah, AR5K_RTS_OK);
252 stats->fcs_error += ath5k_hw_reg_read(ah, AR5K_FCS_FAIL);
253 stats->beacons += ath5k_hw_reg_read(ah, AR5K_BEACON_CNT);
254}
255
256
257/******************\
258* ACK/CTS Timeouts *
259\******************/
260
261/**
262 * ath5k_hw_write_rate_duration() - Fill rate code to duration table
263 * @ah: The &struct ath5k_hw
264 *
265 * Write the rate code to duration table upon hw reset. This is a helper for
266 * ath5k_hw_pcu_init(). It seems all this is doing is setting an ACK timeout on
267 * the hardware, based on current mode, for each rate. The rates which are
268 * capable of short preamble (802.11b rates 2Mbps, 5.5Mbps, and 11Mbps) have
269 * different rate code so we write their value twice (one for long preamble
270 * and one for short).
271 *
272 * Note: Band doesn't matter here, if we set the values for OFDM it works
273 * on both a and g modes. So all we have to do is set values for all g rates
274 * that include all OFDM and CCK rates.
275 *
276 */
277static inline void
278ath5k_hw_write_rate_duration(struct ath5k_hw *ah)
279{
280 struct ieee80211_rate *rate;
281 unsigned int i;
282 /* 802.11g covers both OFDM and CCK */
283 u8 band = NL80211_BAND_2GHZ;
284
285 /* Write rate duration table */
286 for (i = 0; i < ah->sbands[band].n_bitrates; i++) {
287 u32 reg;
288 u16 tx_time;
289
290 if (ah->ah_ack_bitrate_high)
291 rate = &ah->sbands[band].bitrates[ack_rates_high[i]];
292 /* CCK -> 1Mb */
293 else if (i < 4)
294 rate = &ah->sbands[band].bitrates[0];
295 /* OFDM -> 6Mb */
296 else
297 rate = &ah->sbands[band].bitrates[4];
298
299 /* Set ACK timeout */
300 reg = AR5K_RATE_DUR(rate->hw_value);
301
302 /* An ACK frame consists of 10 bytes. If you add the FCS,
303 * which ieee80211_generic_frame_duration() adds,
304 * its 14 bytes. Note we use the control rate and not the
305 * actual rate for this rate. See mac80211 tx.c
306 * ieee80211_duration() for a brief description of
307 * what rate we should choose to TX ACKs. */
308 tx_time = ath5k_hw_get_frame_duration(ah, band, len: 10,
309 rate, shortpre: false);
310
311 ath5k_hw_reg_write(ah, val: tx_time, reg);
312
313 if (!(rate->flags & IEEE80211_RATE_SHORT_PREAMBLE))
314 continue;
315
316 tx_time = ath5k_hw_get_frame_duration(ah, band, len: 10, rate, shortpre: true);
317 ath5k_hw_reg_write(ah, val: tx_time,
318 reg: reg + (AR5K_SET_SHORT_PREAMBLE << 2));
319 }
320}
321
322/**
323 * ath5k_hw_set_ack_timeout() - Set ACK timeout on PCU
324 * @ah: The &struct ath5k_hw
325 * @timeout: Timeout in usec
326 */
327static int
328ath5k_hw_set_ack_timeout(struct ath5k_hw *ah, unsigned int timeout)
329{
330 if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK))
331 <= timeout)
332 return -EINVAL;
333
334 AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_ACK,
335 ath5k_hw_htoclock(ah, timeout));
336
337 return 0;
338}
339
340/**
341 * ath5k_hw_set_cts_timeout() - Set CTS timeout on PCU
342 * @ah: The &struct ath5k_hw
343 * @timeout: Timeout in usec
344 */
345static int
346ath5k_hw_set_cts_timeout(struct ath5k_hw *ah, unsigned int timeout)
347{
348 if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS))
349 <= timeout)
350 return -EINVAL;
351
352 AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_CTS,
353 ath5k_hw_htoclock(ah, timeout));
354
355 return 0;
356}
357
358
359/*******************\
360* RX filter Control *
361\*******************/
362
363/**
364 * ath5k_hw_set_lladdr() - Set station id
365 * @ah: The &struct ath5k_hw
366 * @mac: The card's mac address (array of octets)
367 *
368 * Set station id on hw using the provided mac address
369 */
370int
371ath5k_hw_set_lladdr(struct ath5k_hw *ah, const u8 *mac)
372{
373 struct ath_common *common = ath5k_hw_common(ah);
374 u32 low_id, high_id;
375 u32 pcu_reg;
376
377 /* Set new station ID */
378 memcpy(common->macaddr, mac, ETH_ALEN);
379
380 pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
381
382 low_id = get_unaligned_le32(p: mac);
383 high_id = get_unaligned_le16(p: mac + 4);
384
385 ath5k_hw_reg_write(ah, val: low_id, AR5K_STA_ID0);
386 ath5k_hw_reg_write(ah, val: pcu_reg | high_id, AR5K_STA_ID1);
387
388 return 0;
389}
390
391/**
392 * ath5k_hw_set_bssid() - Set current BSSID on hw
393 * @ah: The &struct ath5k_hw
394 *
395 * Sets the current BSSID and BSSID mask we have from the
396 * common struct into the hardware
397 */
398void
399ath5k_hw_set_bssid(struct ath5k_hw *ah)
400{
401 struct ath_common *common = ath5k_hw_common(ah);
402 u16 tim_offset = 0;
403
404 /*
405 * Set BSSID mask on 5212
406 */
407 if (ah->ah_version == AR5K_AR5212)
408 ath_hw_setbssidmask(common);
409
410 /*
411 * Set BSSID
412 */
413 ath5k_hw_reg_write(ah,
414 val: get_unaligned_le32(p: common->curbssid),
415 AR5K_BSS_ID0);
416 ath5k_hw_reg_write(ah,
417 val: get_unaligned_le16(p: common->curbssid + 4) |
418 ((common->curaid & 0x3fff) << AR5K_BSS_ID1_AID_S),
419 AR5K_BSS_ID1);
420
421 if (common->curaid == 0) {
422 ath5k_hw_disable_pspoll(ah);
423 return;
424 }
425
426 AR5K_REG_WRITE_BITS(ah, AR5K_BEACON, AR5K_BEACON_TIM,
427 tim_offset ? tim_offset + 4 : 0);
428
429 ath5k_hw_enable_pspoll(ah, NULL, assoc_id: 0);
430}
431
432/**
433 * ath5k_hw_set_bssid_mask() - Filter out bssids we listen
434 * @ah: The &struct ath5k_hw
435 * @mask: The BSSID mask to set (array of octets)
436 *
437 * BSSID masking is a method used by AR5212 and newer hardware to inform PCU
438 * which bits of the interface's MAC address should be looked at when trying
439 * to decide which packets to ACK. In station mode and AP mode with a single
440 * BSS every bit matters since we lock to only one BSS. In AP mode with
441 * multiple BSSes (virtual interfaces) not every bit matters because hw must
442 * accept frames for all BSSes and so we tweak some bits of our mac address
443 * in order to have multiple BSSes.
444 *
445 * For more information check out ../hw.c of the common ath module.
446 */
447void
448ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
449{
450 struct ath_common *common = ath5k_hw_common(ah);
451
452 /* Cache bssid mask so that we can restore it
453 * on reset */
454 memcpy(common->bssidmask, mask, ETH_ALEN);
455 if (ah->ah_version == AR5K_AR5212)
456 ath_hw_setbssidmask(common);
457}
458
459/**
460 * ath5k_hw_set_mcast_filter() - Set multicast filter
461 * @ah: The &struct ath5k_hw
462 * @filter0: Lower 32bits of muticast filter
463 * @filter1: Higher 16bits of multicast filter
464 */
465void
466ath5k_hw_set_mcast_filter(struct ath5k_hw *ah, u32 filter0, u32 filter1)
467{
468 ath5k_hw_reg_write(ah, val: filter0, AR5K_MCAST_FILTER0);
469 ath5k_hw_reg_write(ah, val: filter1, AR5K_MCAST_FILTER1);
470}
471
472/**
473 * ath5k_hw_get_rx_filter() - Get current rx filter
474 * @ah: The &struct ath5k_hw
475 *
476 * Returns the RX filter by reading rx filter and
477 * phy error filter registers. RX filter is used
478 * to set the allowed frame types that PCU will accept
479 * and pass to the driver. For a list of frame types
480 * check out reg.h.
481 */
482u32
483ath5k_hw_get_rx_filter(struct ath5k_hw *ah)
484{
485 u32 data, filter = 0;
486
487 filter = ath5k_hw_reg_read(ah, AR5K_RX_FILTER);
488
489 /*Radar detection for 5212*/
490 if (ah->ah_version == AR5K_AR5212) {
491 data = ath5k_hw_reg_read(ah, AR5K_PHY_ERR_FIL);
492
493 if (data & AR5K_PHY_ERR_FIL_RADAR)
494 filter |= AR5K_RX_FILTER_RADARERR;
495 if (data & (AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK))
496 filter |= AR5K_RX_FILTER_PHYERR;
497 }
498
499 return filter;
500}
501
502/**
503 * ath5k_hw_set_rx_filter() - Set rx filter
504 * @ah: The &struct ath5k_hw
505 * @filter: RX filter mask (see reg.h)
506 *
507 * Sets RX filter register and also handles PHY error filter
508 * register on 5212 and newer chips so that we have proper PHY
509 * error reporting.
510 */
511void
512ath5k_hw_set_rx_filter(struct ath5k_hw *ah, u32 filter)
513{
514 u32 data = 0;
515
516 /* Set PHY error filter register on 5212*/
517 if (ah->ah_version == AR5K_AR5212) {
518 if (filter & AR5K_RX_FILTER_RADARERR)
519 data |= AR5K_PHY_ERR_FIL_RADAR;
520 if (filter & AR5K_RX_FILTER_PHYERR)
521 data |= AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK;
522 }
523
524 /*
525 * The AR5210 uses promiscuous mode to detect radar activity
526 */
527 if (ah->ah_version == AR5K_AR5210 &&
528 (filter & AR5K_RX_FILTER_RADARERR)) {
529 filter &= ~AR5K_RX_FILTER_RADARERR;
530 filter |= AR5K_RX_FILTER_PROM;
531 }
532
533 /*Zero length DMA (phy error reporting) */
534 if (data)
535 AR5K_REG_ENABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
536 else
537 AR5K_REG_DISABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
538
539 /*Write RX Filter register*/
540 ath5k_hw_reg_write(ah, val: filter & 0xff, AR5K_RX_FILTER);
541
542 /*Write PHY error filter register on 5212*/
543 if (ah->ah_version == AR5K_AR5212)
544 ath5k_hw_reg_write(ah, val: data, AR5K_PHY_ERR_FIL);
545
546}
547
548
549/****************\
550* Beacon control *
551\****************/
552
553#define ATH5K_MAX_TSF_READ 10
554
555/**
556 * ath5k_hw_get_tsf64() - Get the full 64bit TSF
557 * @ah: The &struct ath5k_hw
558 *
559 * Returns the current TSF
560 */
561u64
562ath5k_hw_get_tsf64(struct ath5k_hw *ah)
563{
564 u32 tsf_lower, tsf_upper1, tsf_upper2;
565 int i;
566 unsigned long flags;
567
568 /* This code is time critical - we don't want to be interrupted here */
569 local_irq_save(flags);
570
571 /*
572 * While reading TSF upper and then lower part, the clock is still
573 * counting (or jumping in case of IBSS merge) so we might get
574 * inconsistent values. To avoid this, we read the upper part again
575 * and check it has not been changed. We make the hypothesis that a
576 * maximum of 3 changes can happens in a row (we use 10 as a safe
577 * value).
578 *
579 * Impact on performance is pretty small, since in most cases, only
580 * 3 register reads are needed.
581 */
582
583 tsf_upper1 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
584 for (i = 0; i < ATH5K_MAX_TSF_READ; i++) {
585 tsf_lower = ath5k_hw_reg_read(ah, AR5K_TSF_L32);
586 tsf_upper2 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
587 if (tsf_upper2 == tsf_upper1)
588 break;
589 tsf_upper1 = tsf_upper2;
590 }
591
592 local_irq_restore(flags);
593
594 WARN_ON(i == ATH5K_MAX_TSF_READ);
595
596 return ((u64)tsf_upper1 << 32) | tsf_lower;
597}
598
599#undef ATH5K_MAX_TSF_READ
600
601/**
602 * ath5k_hw_set_tsf64() - Set a new 64bit TSF
603 * @ah: The &struct ath5k_hw
604 * @tsf64: The new 64bit TSF
605 *
606 * Sets the new TSF
607 */
608void
609ath5k_hw_set_tsf64(struct ath5k_hw *ah, u64 tsf64)
610{
611 ath5k_hw_reg_write(ah, val: tsf64 & 0xffffffff, AR5K_TSF_L32);
612 ath5k_hw_reg_write(ah, val: (tsf64 >> 32) & 0xffffffff, AR5K_TSF_U32);
613}
614
615/**
616 * ath5k_hw_reset_tsf() - Force a TSF reset
617 * @ah: The &struct ath5k_hw
618 *
619 * Forces a TSF reset on PCU
620 */
621void
622ath5k_hw_reset_tsf(struct ath5k_hw *ah)
623{
624 u32 val;
625
626 val = ath5k_hw_reg_read(ah, AR5K_BEACON) | AR5K_BEACON_RESET_TSF;
627
628 /*
629 * Each write to the RESET_TSF bit toggles a hardware internal
630 * signal to reset TSF, but if left high it will cause a TSF reset
631 * on the next chip reset as well. Thus we always write the value
632 * twice to clear the signal.
633 */
634 ath5k_hw_reg_write(ah, val, AR5K_BEACON);
635 ath5k_hw_reg_write(ah, val, AR5K_BEACON);
636}
637
638/**
639 * ath5k_hw_init_beacon_timers() - Initialize beacon timers
640 * @ah: The &struct ath5k_hw
641 * @next_beacon: Next TBTT
642 * @interval: Current beacon interval
643 *
644 * This function is used to initialize beacon timers based on current
645 * operation mode and settings.
646 */
647void
648ath5k_hw_init_beacon_timers(struct ath5k_hw *ah, u32 next_beacon, u32 interval)
649{
650 u32 timer1, timer2, timer3;
651
652 /*
653 * Set the additional timers by mode
654 */
655 switch (ah->opmode) {
656 case NL80211_IFTYPE_MONITOR:
657 case NL80211_IFTYPE_STATION:
658 /* In STA mode timer1 is used as next wakeup
659 * timer and timer2 as next CFP duration start
660 * timer. Both in 1/8TUs. */
661 /* TODO: PCF handling */
662 if (ah->ah_version == AR5K_AR5210) {
663 timer1 = 0xffffffff;
664 timer2 = 0xffffffff;
665 } else {
666 timer1 = 0x0000ffff;
667 timer2 = 0x0007ffff;
668 }
669 /* Mark associated AP as PCF incapable for now */
670 AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PCF);
671 break;
672 case NL80211_IFTYPE_ADHOC:
673 AR5K_REG_ENABLE_BITS(ah, AR5K_TXCFG, AR5K_TXCFG_ADHOC_BCN_ATIM);
674 fallthrough;
675 default:
676 /* On non-STA modes timer1 is used as next DMA
677 * beacon alert (DBA) timer and timer2 as next
678 * software beacon alert. Both in 1/8TUs. */
679 timer1 = (next_beacon - AR5K_TUNE_DMA_BEACON_RESP) << 3;
680 timer2 = (next_beacon - AR5K_TUNE_SW_BEACON_RESP) << 3;
681 break;
682 }
683
684 /* Timer3 marks the end of our ATIM window
685 * a zero length window is not allowed because
686 * we 'll get no beacons */
687 timer3 = next_beacon + 1;
688
689 /*
690 * Set the beacon register and enable all timers.
691 */
692 /* When in AP or Mesh Point mode zero timer0 to start TSF */
693 if (ah->opmode == NL80211_IFTYPE_AP ||
694 ah->opmode == NL80211_IFTYPE_MESH_POINT)
695 ath5k_hw_reg_write(ah, val: 0, AR5K_TIMER0);
696
697 ath5k_hw_reg_write(ah, val: next_beacon, AR5K_TIMER0);
698 ath5k_hw_reg_write(ah, val: timer1, AR5K_TIMER1);
699 ath5k_hw_reg_write(ah, val: timer2, AR5K_TIMER2);
700 ath5k_hw_reg_write(ah, val: timer3, AR5K_TIMER3);
701
702 /* Force a TSF reset if requested and enable beacons */
703 if (interval & AR5K_BEACON_RESET_TSF)
704 ath5k_hw_reset_tsf(ah);
705
706 ath5k_hw_reg_write(ah, val: interval & (AR5K_BEACON_PERIOD |
707 AR5K_BEACON_ENABLE),
708 AR5K_BEACON);
709
710 /* Flush any pending BMISS interrupts on ISR by
711 * performing a clear-on-write operation on PISR
712 * register for the BMISS bit (writing a bit on
713 * ISR toggles a reset for that bit and leaves
714 * the remaining bits intact) */
715 if (ah->ah_version == AR5K_AR5210)
716 ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_ISR);
717 else
718 ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_PISR);
719
720 /* TODO: Set enhanced sleep registers on AR5212
721 * based on vif->bss_conf params, until then
722 * disable power save reporting.*/
723 AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PWR_SV);
724
725}
726
727/**
728 * ath5k_check_timer_win() - Check if timer B is timer A + window
729 * @a: timer a (before b)
730 * @b: timer b (after a)
731 * @window: difference between a and b
732 * @intval: timers are increased by this interval
733 *
734 * This helper function checks if timer B is timer A + window and covers
735 * cases where timer A or B might have already been updated or wrapped
736 * around (Timers are 16 bit).
737 *
738 * Returns true if O.K.
739 */
740static inline bool
741ath5k_check_timer_win(int a, int b, int window, int intval)
742{
743 /*
744 * 1.) usually B should be A + window
745 * 2.) A already updated, B not updated yet
746 * 3.) A already updated and has wrapped around
747 * 4.) B has wrapped around
748 */
749 if ((b - a == window) || /* 1.) */
750 (a - b == intval - window) || /* 2.) */
751 ((a | 0x10000) - b == intval - window) || /* 3.) */
752 ((b | 0x10000) - a == window)) /* 4.) */
753 return true; /* O.K. */
754 return false;
755}
756
757/**
758 * ath5k_hw_check_beacon_timers() - Check if the beacon timers are correct
759 * @ah: The &struct ath5k_hw
760 * @intval: beacon interval
761 *
762 * This is a workaround for IBSS mode
763 *
764 * The need for this function arises from the fact that we have 4 separate
765 * HW timer registers (TIMER0 - TIMER3), which are closely related to the
766 * next beacon target time (NBTT), and that the HW updates these timers
767 * separately based on the current TSF value. The hardware increments each
768 * timer by the beacon interval, when the local TSF converted to TU is equal
769 * to the value stored in the timer.
770 *
771 * The reception of a beacon with the same BSSID can update the local HW TSF
772 * at any time - this is something we can't avoid. If the TSF jumps to a
773 * time which is later than the time stored in a timer, this timer will not
774 * be updated until the TSF in TU wraps around at 16 bit (the size of the
775 * timers) and reaches the time which is stored in the timer.
776 *
777 * The problem is that these timers are closely related to TIMER0 (NBTT) and
778 * that they define a time "window". When the TSF jumps between two timers
779 * (e.g. ATIM and NBTT), the one in the past will be left behind (not
780 * updated), while the one in the future will be updated every beacon
781 * interval. This causes the window to get larger, until the TSF wraps
782 * around as described above and the timer which was left behind gets
783 * updated again. But - because the beacon interval is usually not an exact
784 * divisor of the size of the timers (16 bit), an unwanted "window" between
785 * these timers has developed!
786 *
787 * This is especially important with the ATIM window, because during
788 * the ATIM window only ATIM frames and no data frames are allowed to be
789 * sent, which creates transmission pauses after each beacon. This symptom
790 * has been described as "ramping ping" because ping times increase linearly
791 * for some time and then drop down again. A wrong window on the DMA beacon
792 * timer has the same effect, so we check for these two conditions.
793 *
794 * Returns true if O.K.
795 */
796bool
797ath5k_hw_check_beacon_timers(struct ath5k_hw *ah, int intval)
798{
799 unsigned int nbtt, atim, dma;
800
801 nbtt = ath5k_hw_reg_read(ah, AR5K_TIMER0);
802 atim = ath5k_hw_reg_read(ah, AR5K_TIMER3);
803 dma = ath5k_hw_reg_read(ah, AR5K_TIMER1) >> 3;
804
805 /* NOTE: SWBA is different. Having a wrong window there does not
806 * stop us from sending data and this condition is caught by
807 * other means (SWBA interrupt) */
808
809 if (ath5k_check_timer_win(a: nbtt, b: atim, window: 1, intval) &&
810 ath5k_check_timer_win(a: dma, b: nbtt, AR5K_TUNE_DMA_BEACON_RESP,
811 intval))
812 return true; /* O.K. */
813 return false;
814}
815
816/**
817 * ath5k_hw_set_coverage_class() - Set IEEE 802.11 coverage class
818 * @ah: The &struct ath5k_hw
819 * @coverage_class: IEEE 802.11 coverage class number
820 *
821 * Sets IFS intervals and ACK/CTS timeouts for given coverage class.
822 */
823void
824ath5k_hw_set_coverage_class(struct ath5k_hw *ah, u8 coverage_class)
825{
826 /* As defined by IEEE 802.11-2007 17.3.8.6 */
827 int slot_time = ath5k_hw_get_default_slottime(ah) + 3 * coverage_class;
828 int ack_timeout = ath5k_hw_get_default_sifs(ah) + slot_time;
829 int cts_timeout = ack_timeout;
830
831 ath5k_hw_set_ifs_intervals(ah, slot_time);
832 ath5k_hw_set_ack_timeout(ah, timeout: ack_timeout);
833 ath5k_hw_set_cts_timeout(ah, timeout: cts_timeout);
834
835 ah->ah_coverage_class = coverage_class;
836}
837
838/***************************\
839* Init/Start/Stop functions *
840\***************************/
841
842/**
843 * ath5k_hw_start_rx_pcu() - Start RX engine
844 * @ah: The &struct ath5k_hw
845 *
846 * Starts RX engine on PCU so that hw can process RXed frames
847 * (ACK etc).
848 *
849 * NOTE: RX DMA should be already enabled using ath5k_hw_start_rx_dma
850 */
851void
852ath5k_hw_start_rx_pcu(struct ath5k_hw *ah)
853{
854 AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
855}
856
857/**
858 * ath5k_hw_stop_rx_pcu() - Stop RX engine
859 * @ah: The &struct ath5k_hw
860 *
861 * Stops RX engine on PCU
862 */
863void
864ath5k_hw_stop_rx_pcu(struct ath5k_hw *ah)
865{
866 AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
867}
868
869/**
870 * ath5k_hw_set_opmode() - Set PCU operating mode
871 * @ah: The &struct ath5k_hw
872 * @op_mode: One of enum nl80211_iftype
873 *
874 * Configure PCU for the various operating modes (AP/STA etc)
875 */
876int
877ath5k_hw_set_opmode(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
878{
879 struct ath_common *common = ath5k_hw_common(ah);
880 u32 pcu_reg, beacon_reg, low_id, high_id;
881
882 ATH5K_DBG(ah, ATH5K_DEBUG_MODE, "mode %d\n", op_mode);
883
884 /* Preserve rest settings */
885 pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
886 pcu_reg &= ~(AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_AP
887 | AR5K_STA_ID1_KEYSRCH_MODE
888 | (ah->ah_version == AR5K_AR5210 ?
889 (AR5K_STA_ID1_PWR_SV | AR5K_STA_ID1_NO_PSPOLL) : 0));
890
891 beacon_reg = 0;
892
893 switch (op_mode) {
894 case NL80211_IFTYPE_ADHOC:
895 pcu_reg |= AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_KEYSRCH_MODE;
896 beacon_reg |= AR5K_BCR_ADHOC;
897 if (ah->ah_version == AR5K_AR5210)
898 pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
899 else
900 AR5K_REG_ENABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
901 break;
902
903 case NL80211_IFTYPE_AP:
904 case NL80211_IFTYPE_MESH_POINT:
905 pcu_reg |= AR5K_STA_ID1_AP | AR5K_STA_ID1_KEYSRCH_MODE;
906 beacon_reg |= AR5K_BCR_AP;
907 if (ah->ah_version == AR5K_AR5210)
908 pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
909 else
910 AR5K_REG_DISABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
911 break;
912
913 case NL80211_IFTYPE_STATION:
914 pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
915 | (ah->ah_version == AR5K_AR5210 ?
916 AR5K_STA_ID1_PWR_SV : 0);
917 fallthrough;
918 case NL80211_IFTYPE_MONITOR:
919 pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
920 | (ah->ah_version == AR5K_AR5210 ?
921 AR5K_STA_ID1_NO_PSPOLL : 0);
922 break;
923
924 default:
925 return -EINVAL;
926 }
927
928 /*
929 * Set PCU registers
930 */
931 low_id = get_unaligned_le32(p: common->macaddr);
932 high_id = get_unaligned_le16(p: common->macaddr + 4);
933 ath5k_hw_reg_write(ah, val: low_id, AR5K_STA_ID0);
934 ath5k_hw_reg_write(ah, val: pcu_reg | high_id, AR5K_STA_ID1);
935
936 /*
937 * Set Beacon Control Register on 5210
938 */
939 if (ah->ah_version == AR5K_AR5210)
940 ath5k_hw_reg_write(ah, val: beacon_reg, AR5K_BCR);
941
942 return 0;
943}
944
945/**
946 * ath5k_hw_pcu_init() - Initialize PCU
947 * @ah: The &struct ath5k_hw
948 * @op_mode: One of enum nl80211_iftype
949 *
950 * This function is used to initialize PCU by setting current
951 * operation mode and various other settings.
952 */
953void
954ath5k_hw_pcu_init(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
955{
956 /* Set bssid and bssid mask */
957 ath5k_hw_set_bssid(ah);
958
959 /* Set PCU config */
960 ath5k_hw_set_opmode(ah, op_mode);
961
962 /* Write rate duration table only on AR5212 and if
963 * virtual interface has already been brought up
964 * XXX: rethink this after new mode changes to
965 * mac80211 are integrated */
966 if (ah->ah_version == AR5K_AR5212 &&
967 ah->nvifs)
968 ath5k_hw_write_rate_duration(ah);
969
970 /* Set RSSI/BRSSI thresholds
971 *
972 * Note: If we decide to set this value
973 * dynamically, have in mind that when AR5K_RSSI_THR
974 * register is read it might return 0x40 if we haven't
975 * wrote anything to it plus BMISS RSSI threshold is zeroed.
976 * So doing a save/restore procedure here isn't the right
977 * choice. Instead store it on ath5k_hw */
978 ath5k_hw_reg_write(ah, val: (AR5K_TUNE_RSSI_THRES |
979 AR5K_TUNE_BMISS_THRES <<
980 AR5K_RSSI_THR_BMISS_S),
981 AR5K_RSSI_THR);
982
983 /* MIC QoS support */
984 if (ah->ah_mac_srev >= AR5K_SREV_AR2413) {
985 ath5k_hw_reg_write(ah, val: 0x000100aa, AR5K_MIC_QOS_CTL);
986 ath5k_hw_reg_write(ah, val: 0x00003210, AR5K_MIC_QOS_SEL);
987 }
988
989 /* QoS NOACK Policy */
990 if (ah->ah_version == AR5K_AR5212) {
991 ath5k_hw_reg_write(ah,
992 AR5K_REG_SM(2, AR5K_QOS_NOACK_2BIT_VALUES) |
993 AR5K_REG_SM(5, AR5K_QOS_NOACK_BIT_OFFSET) |
994 AR5K_REG_SM(0, AR5K_QOS_NOACK_BYTE_OFFSET),
995 AR5K_QOS_NOACK);
996 }
997
998 /* Restore slot time and ACK timeouts */
999 if (ah->ah_coverage_class > 0)
1000 ath5k_hw_set_coverage_class(ah, coverage_class: ah->ah_coverage_class);
1001
1002 /* Set ACK bitrate mode (see ack_rates_high) */
1003 if (ah->ah_version == AR5K_AR5212) {
1004 u32 val = AR5K_STA_ID1_BASE_RATE_11B | AR5K_STA_ID1_ACKCTS_6MB;
1005 if (ah->ah_ack_bitrate_high)
1006 AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, val);
1007 else
1008 AR5K_REG_ENABLE_BITS(ah, AR5K_STA_ID1, val);
1009 }
1010 return;
1011}
1012

source code of linux/drivers/net/wireless/ath/ath5k/pcu.c