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 */
82 static 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 * @len: Frame's length in bytes
105 * @rate: The @struct ieee80211_rate
106 * @shortpre: Indicate short preample
107 *
108 * Calculate tx duration of a frame given it's rate and length
109 * It extends ieee80211_generic_frame_duration for non standard
110 * bwmodes.
111 */
112 int
113 ath5k_hw_get_frame_duration(struct ath5k_hw *ah, enum nl80211_band band,
114 int len, struct ieee80211_rate *rate, bool shortpre)
115 {
116 int sifs, preamble, plcp_bits, sym_time;
117 int bitrate, bits, symbols, symbol_bits;
118 int dur;
119
120 /* Fallback */
121 if (!ah->ah_bwmode) {
122 __le16 raw_dur = ieee80211_generic_frame_duration(ah->hw,
123 NULL, band, len, rate);
124
125 /* subtract difference between long and short preamble */
126 dur = le16_to_cpu(raw_dur);
127 if (shortpre)
128 dur -= 96;
129
130 return dur;
131 }
132
133 bitrate = rate->bitrate;
134 preamble = AR5K_INIT_OFDM_PREAMPLE_TIME;
135 plcp_bits = AR5K_INIT_OFDM_PLCP_BITS;
136 sym_time = AR5K_INIT_OFDM_SYMBOL_TIME;
137
138 switch (ah->ah_bwmode) {
139 case AR5K_BWMODE_40MHZ:
140 sifs = AR5K_INIT_SIFS_TURBO;
141 preamble = AR5K_INIT_OFDM_PREAMBLE_TIME_MIN;
142 break;
143 case AR5K_BWMODE_10MHZ:
144 sifs = AR5K_INIT_SIFS_HALF_RATE;
145 preamble *= 2;
146 sym_time *= 2;
147 bitrate = DIV_ROUND_UP(bitrate, 2);
148 break;
149 case AR5K_BWMODE_5MHZ:
150 sifs = AR5K_INIT_SIFS_QUARTER_RATE;
151 preamble *= 4;
152 sym_time *= 4;
153 bitrate = DIV_ROUND_UP(bitrate, 4);
154 break;
155 default:
156 sifs = AR5K_INIT_SIFS_DEFAULT_BG;
157 break;
158 }
159
160 bits = plcp_bits + (len << 3);
161 /* Bit rate is in 100Kbits */
162 symbol_bits = bitrate * sym_time;
163 symbols = DIV_ROUND_UP(bits * 10, symbol_bits);
164
165 dur = sifs + preamble + (sym_time * symbols);
166
167 return dur;
168 }
169
170 /**
171 * ath5k_hw_get_default_slottime() - Get the default slot time for current mode
172 * @ah: The &struct ath5k_hw
173 */
174 unsigned int
175 ath5k_hw_get_default_slottime(struct ath5k_hw *ah)
176 {
177 struct ieee80211_channel *channel = ah->ah_current_channel;
178 unsigned int slot_time;
179
180 switch (ah->ah_bwmode) {
181 case AR5K_BWMODE_40MHZ:
182 slot_time = AR5K_INIT_SLOT_TIME_TURBO;
183 break;
184 case AR5K_BWMODE_10MHZ:
185 slot_time = AR5K_INIT_SLOT_TIME_HALF_RATE;
186 break;
187 case AR5K_BWMODE_5MHZ:
188 slot_time = AR5K_INIT_SLOT_TIME_QUARTER_RATE;
189 break;
190 case AR5K_BWMODE_DEFAULT:
191 default:
192 slot_time = AR5K_INIT_SLOT_TIME_DEFAULT;
193 if ((channel->hw_value == AR5K_MODE_11B) && !ah->ah_short_slot)
194 slot_time = AR5K_INIT_SLOT_TIME_B;
195 break;
196 }
197
198 return slot_time;
199 }
200
201 /**
202 * ath5k_hw_get_default_sifs() - Get the default SIFS for current mode
203 * @ah: The &struct ath5k_hw
204 */
205 unsigned int
206 ath5k_hw_get_default_sifs(struct ath5k_hw *ah)
207 {
208 struct ieee80211_channel *channel = ah->ah_current_channel;
209 unsigned int sifs;
210
211 switch (ah->ah_bwmode) {
212 case AR5K_BWMODE_40MHZ:
213 sifs = AR5K_INIT_SIFS_TURBO;
214 break;
215 case AR5K_BWMODE_10MHZ:
216 sifs = AR5K_INIT_SIFS_HALF_RATE;
217 break;
218 case AR5K_BWMODE_5MHZ:
219 sifs = AR5K_INIT_SIFS_QUARTER_RATE;
220 break;
221 case AR5K_BWMODE_DEFAULT:
222 default:
223 sifs = AR5K_INIT_SIFS_DEFAULT_BG;
224 if (channel->band == NL80211_BAND_5GHZ)
225 sifs = AR5K_INIT_SIFS_DEFAULT_A;
226 break;
227 }
228
229 return sifs;
230 }
231
232 /**
233 * ath5k_hw_update_mib_counters() - Update MIB counters (mac layer statistics)
234 * @ah: The &struct ath5k_hw
235 *
236 * Reads MIB counters from PCU and updates sw statistics. Is called after a
237 * MIB interrupt, because one of these counters might have reached their maximum
238 * and triggered the MIB interrupt, to let us read and clear the counter.
239 *
240 * NOTE: Is called in interrupt context!
241 */
242 void
243 ath5k_hw_update_mib_counters(struct ath5k_hw *ah)
244 {
245 struct ath5k_statistics *stats = &ah->stats;
246
247 /* Read-And-Clear */
248 stats->ack_fail += ath5k_hw_reg_read(ah, AR5K_ACK_FAIL);
249 stats->rts_fail += ath5k_hw_reg_read(ah, AR5K_RTS_FAIL);
250 stats->rts_ok += ath5k_hw_reg_read(ah, AR5K_RTS_OK);
251 stats->fcs_error += ath5k_hw_reg_read(ah, AR5K_FCS_FAIL);
252 stats->beacons += ath5k_hw_reg_read(ah, AR5K_BEACON_CNT);
253 }
254
255
256 /******************\
257 * ACK/CTS Timeouts *
258 \******************/
259
260 /**
261 * ath5k_hw_write_rate_duration() - Fill rate code to duration table
262 * @ah: The &struct ath5k_hw
263 *
264 * Write the rate code to duration table upon hw reset. This is a helper for
265 * ath5k_hw_pcu_init(). It seems all this is doing is setting an ACK timeout on
266 * the hardware, based on current mode, for each rate. The rates which are
267 * capable of short preamble (802.11b rates 2Mbps, 5.5Mbps, and 11Mbps) have
268 * different rate code so we write their value twice (one for long preamble
269 * and one for short).
270 *
271 * Note: Band doesn't matter here, if we set the values for OFDM it works
272 * on both a and g modes. So all we have to do is set values for all g rates
273 * that include all OFDM and CCK rates.
274 *
275 */
276 static inline void
277 ath5k_hw_write_rate_duration(struct ath5k_hw *ah)
278 {
279 struct ieee80211_rate *rate;
280 unsigned int i;
281 /* 802.11g covers both OFDM and CCK */
282 u8 band = NL80211_BAND_2GHZ;
283
284 /* Write rate duration table */
285 for (i = 0; i < ah->sbands[band].n_bitrates; i++) {
286 u32 reg;
287 u16 tx_time;
288
289 if (ah->ah_ack_bitrate_high)
290 rate = &ah->sbands[band].bitrates[ack_rates_high[i]];
291 /* CCK -> 1Mb */
292 else if (i < 4)
293 rate = &ah->sbands[band].bitrates[0];
294 /* OFDM -> 6Mb */
295 else
296 rate = &ah->sbands[band].bitrates[4];
297
298 /* Set ACK timeout */
299 reg = AR5K_RATE_DUR(rate->hw_value);
300
301 /* An ACK frame consists of 10 bytes. If you add the FCS,
302 * which ieee80211_generic_frame_duration() adds,
303 * its 14 bytes. Note we use the control rate and not the
304 * actual rate for this rate. See mac80211 tx.c
305 * ieee80211_duration() for a brief description of
306 * what rate we should choose to TX ACKs. */
307 tx_time = ath5k_hw_get_frame_duration(ah, band, 10,
308 rate, false);
309
310 ath5k_hw_reg_write(ah, tx_time, reg);
311
312 if (!(rate->flags & IEEE80211_RATE_SHORT_PREAMBLE))
313 continue;
314
315 tx_time = ath5k_hw_get_frame_duration(ah, band, 10, rate, true);
316 ath5k_hw_reg_write(ah, tx_time,
317 reg + (AR5K_SET_SHORT_PREAMBLE << 2));
318 }
319 }
320
321 /**
322 * ath5k_hw_set_ack_timeout() - Set ACK timeout on PCU
323 * @ah: The &struct ath5k_hw
324 * @timeout: Timeout in usec
325 */
326 static int
327 ath5k_hw_set_ack_timeout(struct ath5k_hw *ah, unsigned int timeout)
328 {
329 if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK))
330 <= timeout)
331 return -EINVAL;
332
333 AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_ACK,
334 ath5k_hw_htoclock(ah, timeout));
335
336 return 0;
337 }
338
339 /**
340 * ath5k_hw_set_cts_timeout() - Set CTS timeout on PCU
341 * @ah: The &struct ath5k_hw
342 * @timeout: Timeout in usec
343 */
344 static int
345 ath5k_hw_set_cts_timeout(struct ath5k_hw *ah, unsigned int timeout)
346 {
347 if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS))
348 <= timeout)
349 return -EINVAL;
350
351 AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_CTS,
352 ath5k_hw_htoclock(ah, timeout));
353
354 return 0;
355 }
356
357
358 /*******************\
359 * RX filter Control *
360 \*******************/
361
362 /**
363 * ath5k_hw_set_lladdr() - Set station id
364 * @ah: The &struct ath5k_hw
365 * @mac: The card's mac address (array of octets)
366 *
367 * Set station id on hw using the provided mac address
368 */
369 int
370 ath5k_hw_set_lladdr(struct ath5k_hw *ah, const u8 *mac)
371 {
372 struct ath_common *common = ath5k_hw_common(ah);
373 u32 low_id, high_id;
374 u32 pcu_reg;
375
376 /* Set new station ID */
377 memcpy(common->macaddr, mac, ETH_ALEN);
378
379 pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
380
381 low_id = get_unaligned_le32(mac);
382 high_id = get_unaligned_le16(mac + 4);
383
384 ath5k_hw_reg_write(ah, low_id, AR5K_STA_ID0);
385 ath5k_hw_reg_write(ah, pcu_reg | high_id, AR5K_STA_ID1);
386
387 return 0;
388 }
389
390 /**
391 * ath5k_hw_set_bssid() - Set current BSSID on hw
392 * @ah: The &struct ath5k_hw
393 *
394 * Sets the current BSSID and BSSID mask we have from the
395 * common struct into the hardware
396 */
397 void
398 ath5k_hw_set_bssid(struct ath5k_hw *ah)
399 {
400 struct ath_common *common = ath5k_hw_common(ah);
401 u16 tim_offset = 0;
402
403 /*
404 * Set BSSID mask on 5212
405 */
406 if (ah->ah_version == AR5K_AR5212)
407 ath_hw_setbssidmask(common);
408
409 /*
410 * Set BSSID
411 */
412 ath5k_hw_reg_write(ah,
413 get_unaligned_le32(common->curbssid),
414 AR5K_BSS_ID0);
415 ath5k_hw_reg_write(ah,
416 get_unaligned_le16(common->curbssid + 4) |
417 ((common->curaid & 0x3fff) << AR5K_BSS_ID1_AID_S),
418 AR5K_BSS_ID1);
419
420 if (common->curaid == 0) {
421 ath5k_hw_disable_pspoll(ah);
422 return;
423 }
424
425 AR5K_REG_WRITE_BITS(ah, AR5K_BEACON, AR5K_BEACON_TIM,
426 tim_offset ? tim_offset + 4 : 0);
427
428 ath5k_hw_enable_pspoll(ah, NULL, 0);
429 }
430
431 /**
432 * ath5k_hw_set_bssid_mask() - Filter out bssids we listen
433 * @ah: The &struct ath5k_hw
434 * @mask: The BSSID mask to set (array of octets)
435 *
436 * BSSID masking is a method used by AR5212 and newer hardware to inform PCU
437 * which bits of the interface's MAC address should be looked at when trying
438 * to decide which packets to ACK. In station mode and AP mode with a single
439 * BSS every bit matters since we lock to only one BSS. In AP mode with
440 * multiple BSSes (virtual interfaces) not every bit matters because hw must
441 * accept frames for all BSSes and so we tweak some bits of our mac address
442 * in order to have multiple BSSes.
443 *
444 * For more information check out ../hw.c of the common ath module.
445 */
446 void
447 ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
448 {
449 struct ath_common *common = ath5k_hw_common(ah);
450
451 /* Cache bssid mask so that we can restore it
452 * on reset */
453 memcpy(common->bssidmask, mask, ETH_ALEN);
454 if (ah->ah_version == AR5K_AR5212)
455 ath_hw_setbssidmask(common);
456 }
457
458 /**
459 * ath5k_hw_set_mcast_filter() - Set multicast filter
460 * @ah: The &struct ath5k_hw
461 * @filter0: Lower 32bits of muticast filter
462 * @filter1: Higher 16bits of multicast filter
463 */
464 void
465 ath5k_hw_set_mcast_filter(struct ath5k_hw *ah, u32 filter0, u32 filter1)
466 {
467 ath5k_hw_reg_write(ah, filter0, AR5K_MCAST_FILTER0);
468 ath5k_hw_reg_write(ah, filter1, AR5K_MCAST_FILTER1);
469 }
470
471 /**
472 * ath5k_hw_get_rx_filter() - Get current rx filter
473 * @ah: The &struct ath5k_hw
474 *
475 * Returns the RX filter by reading rx filter and
476 * phy error filter registers. RX filter is used
477 * to set the allowed frame types that PCU will accept
478 * and pass to the driver. For a list of frame types
479 * check out reg.h.
480 */
481 u32
482 ath5k_hw_get_rx_filter(struct ath5k_hw *ah)
483 {
484 u32 data, filter = 0;
485
486 filter = ath5k_hw_reg_read(ah, AR5K_RX_FILTER);
487
488 /*Radar detection for 5212*/
489 if (ah->ah_version == AR5K_AR5212) {
490 data = ath5k_hw_reg_read(ah, AR5K_PHY_ERR_FIL);
491
492 if (data & AR5K_PHY_ERR_FIL_RADAR)
493 filter |= AR5K_RX_FILTER_RADARERR;
494 if (data & (AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK))
495 filter |= AR5K_RX_FILTER_PHYERR;
496 }
497
498 return filter;
499 }
500
501 /**
502 * ath5k_hw_set_rx_filter() - Set rx filter
503 * @ah: The &struct ath5k_hw
504 * @filter: RX filter mask (see reg.h)
505 *
506 * Sets RX filter register and also handles PHY error filter
507 * register on 5212 and newer chips so that we have proper PHY
508 * error reporting.
509 */
510 void
511 ath5k_hw_set_rx_filter(struct ath5k_hw *ah, u32 filter)
512 {
513 u32 data = 0;
514
515 /* Set PHY error filter register on 5212*/
516 if (ah->ah_version == AR5K_AR5212) {
517 if (filter & AR5K_RX_FILTER_RADARERR)
518 data |= AR5K_PHY_ERR_FIL_RADAR;
519 if (filter & AR5K_RX_FILTER_PHYERR)
520 data |= AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK;
521 }
522
523 /*
524 * The AR5210 uses promiscuous mode to detect radar activity
525 */
526 if (ah->ah_version == AR5K_AR5210 &&
527 (filter & AR5K_RX_FILTER_RADARERR)) {
528 filter &= ~AR5K_RX_FILTER_RADARERR;
529 filter |= AR5K_RX_FILTER_PROM;
530 }
531
532 /*Zero length DMA (phy error reporting) */
533 if (data)
534 AR5K_REG_ENABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
535 else
536 AR5K_REG_DISABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
537
538 /*Write RX Filter register*/
539 ath5k_hw_reg_write(ah, filter & 0xff, AR5K_RX_FILTER);
540
541 /*Write PHY error filter register on 5212*/
542 if (ah->ah_version == AR5K_AR5212)
543 ath5k_hw_reg_write(ah, data, AR5K_PHY_ERR_FIL);
544
545 }
546
547
548 /****************\
549 * Beacon control *
550 \****************/
551
552 #define ATH5K_MAX_TSF_READ 10
553
554 /**
555 * ath5k_hw_get_tsf64() - Get the full 64bit TSF
556 * @ah: The &struct ath5k_hw
557 *
558 * Returns the current TSF
559 */
560 u64
561 ath5k_hw_get_tsf64(struct ath5k_hw *ah)
562 {
563 u32 tsf_lower, tsf_upper1, tsf_upper2;
564 int i;
565 unsigned long flags;
566
567 /* This code is time critical - we don't want to be interrupted here */
568 local_irq_save(flags);
569
570 /*
571 * While reading TSF upper and then lower part, the clock is still
572 * counting (or jumping in case of IBSS merge) so we might get
573 * inconsistent values. To avoid this, we read the upper part again
574 * and check it has not been changed. We make the hypothesis that a
575 * maximum of 3 changes can happens in a row (we use 10 as a safe
576 * value).
577 *
578 * Impact on performance is pretty small, since in most cases, only
579 * 3 register reads are needed.
580 */
581
582 tsf_upper1 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
583 for (i = 0; i < ATH5K_MAX_TSF_READ; i++) {
584 tsf_lower = ath5k_hw_reg_read(ah, AR5K_TSF_L32);
585 tsf_upper2 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
586 if (tsf_upper2 == tsf_upper1)
587 break;
588 tsf_upper1 = tsf_upper2;
589 }
590
591 local_irq_restore(flags);
592
593 WARN_ON(i == ATH5K_MAX_TSF_READ);
594
595 return ((u64)tsf_upper1 << 32) | tsf_lower;
596 }
597
598 #undef ATH5K_MAX_TSF_READ
599
600 /**
601 * ath5k_hw_set_tsf64() - Set a new 64bit TSF
602 * @ah: The &struct ath5k_hw
603 * @tsf64: The new 64bit TSF
604 *
605 * Sets the new TSF
606 */
607 void
608 ath5k_hw_set_tsf64(struct ath5k_hw *ah, u64 tsf64)
609 {
610 ath5k_hw_reg_write(ah, tsf64 & 0xffffffff, AR5K_TSF_L32);
611 ath5k_hw_reg_write(ah, (tsf64 >> 32) & 0xffffffff, AR5K_TSF_U32);
612 }
613
614 /**
615 * ath5k_hw_reset_tsf() - Force a TSF reset
616 * @ah: The &struct ath5k_hw
617 *
618 * Forces a TSF reset on PCU
619 */
620 void
621 ath5k_hw_reset_tsf(struct ath5k_hw *ah)
622 {
623 u32 val;
624
625 val = ath5k_hw_reg_read(ah, AR5K_BEACON) | AR5K_BEACON_RESET_TSF;
626
627 /*
628 * Each write to the RESET_TSF bit toggles a hardware internal
629 * signal to reset TSF, but if left high it will cause a TSF reset
630 * on the next chip reset as well. Thus we always write the value
631 * twice to clear the signal.
632 */
633 ath5k_hw_reg_write(ah, val, AR5K_BEACON);
634 ath5k_hw_reg_write(ah, val, AR5K_BEACON);
635 }
636
637 /**
638 * ath5k_hw_init_beacon_timers() - Initialize beacon timers
639 * @ah: The &struct ath5k_hw
640 * @next_beacon: Next TBTT
641 * @interval: Current beacon interval
642 *
643 * This function is used to initialize beacon timers based on current
644 * operation mode and settings.
645 */
646 void
647 ath5k_hw_init_beacon_timers(struct ath5k_hw *ah, u32 next_beacon, u32 interval)
648 {
649 u32 timer1, timer2, timer3;
650
651 /*
652 * Set the additional timers by mode
653 */
654 switch (ah->opmode) {
655 case NL80211_IFTYPE_MONITOR:
656 case NL80211_IFTYPE_STATION:
657 /* In STA mode timer1 is used as next wakeup
658 * timer and timer2 as next CFP duration start
659 * timer. Both in 1/8TUs. */
660 /* TODO: PCF handling */
661 if (ah->ah_version == AR5K_AR5210) {
662 timer1 = 0xffffffff;
663 timer2 = 0xffffffff;
664 } else {
665 timer1 = 0x0000ffff;
666 timer2 = 0x0007ffff;
667 }
668 /* Mark associated AP as PCF incapable for now */
669 AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PCF);
670 break;
671 case NL80211_IFTYPE_ADHOC:
672 AR5K_REG_ENABLE_BITS(ah, AR5K_TXCFG, AR5K_TXCFG_ADHOC_BCN_ATIM);
673 /* fall through */
674 default:
675 /* On non-STA modes timer1 is used as next DMA
676 * beacon alert (DBA) timer and timer2 as next
677 * software beacon alert. Both in 1/8TUs. */
678 timer1 = (next_beacon - AR5K_TUNE_DMA_BEACON_RESP) << 3;
679 timer2 = (next_beacon - AR5K_TUNE_SW_BEACON_RESP) << 3;
680 break;
681 }
682
683 /* Timer3 marks the end of our ATIM window
684 * a zero length window is not allowed because
685 * we 'll get no beacons */
686 timer3 = next_beacon + 1;
687
688 /*
689 * Set the beacon register and enable all timers.
690 */
691 /* When in AP or Mesh Point mode zero timer0 to start TSF */
692 if (ah->opmode == NL80211_IFTYPE_AP ||
693 ah->opmode == NL80211_IFTYPE_MESH_POINT)
694 ath5k_hw_reg_write(ah, 0, AR5K_TIMER0);
695
696 ath5k_hw_reg_write(ah, next_beacon, AR5K_TIMER0);
697 ath5k_hw_reg_write(ah, timer1, AR5K_TIMER1);
698 ath5k_hw_reg_write(ah, timer2, AR5K_TIMER2);
699 ath5k_hw_reg_write(ah, timer3, AR5K_TIMER3);
700
701 /* Force a TSF reset if requested and enable beacons */
702 if (interval & AR5K_BEACON_RESET_TSF)
703 ath5k_hw_reset_tsf(ah);
704
705 ath5k_hw_reg_write(ah, interval & (AR5K_BEACON_PERIOD |
706 AR5K_BEACON_ENABLE),
707 AR5K_BEACON);
708
709 /* Flush any pending BMISS interrupts on ISR by
710 * performing a clear-on-write operation on PISR
711 * register for the BMISS bit (writing a bit on
712 * ISR toggles a reset for that bit and leaves
713 * the remaining bits intact) */
714 if (ah->ah_version == AR5K_AR5210)
715 ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_ISR);
716 else
717 ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_PISR);
718
719 /* TODO: Set enhanced sleep registers on AR5212
720 * based on vif->bss_conf params, until then
721 * disable power save reporting.*/
722 AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PWR_SV);
723
724 }
725
726 /**
727 * ath5k_check_timer_win() - Check if timer B is timer A + window
728 * @a: timer a (before b)
729 * @b: timer b (after a)
730 * @window: difference between a and b
731 * @intval: timers are increased by this interval
732 *
733 * This helper function checks if timer B is timer A + window and covers
734 * cases where timer A or B might have already been updated or wrapped
735 * around (Timers are 16 bit).
736 *
737 * Returns true if O.K.
738 */
739 static inline bool
740 ath5k_check_timer_win(int a, int b, int window, int intval)
741 {
742 /*
743 * 1.) usually B should be A + window
744 * 2.) A already updated, B not updated yet
745 * 3.) A already updated and has wrapped around
746 * 4.) B has wrapped around
747 */
748 if ((b - a == window) || /* 1.) */
749 (a - b == intval - window) || /* 2.) */
750 ((a | 0x10000) - b == intval - window) || /* 3.) */
751 ((b | 0x10000) - a == window)) /* 4.) */
752 return true; /* O.K. */
753 return false;
754 }
755
756 /**
757 * ath5k_hw_check_beacon_timers() - Check if the beacon timers are correct
758 * @ah: The &struct ath5k_hw
759 * @intval: beacon interval
760 *
761 * This is a workaround for IBSS mode
762 *
763 * The need for this function arises from the fact that we have 4 separate
764 * HW timer registers (TIMER0 - TIMER3), which are closely related to the
765 * next beacon target time (NBTT), and that the HW updates these timers
766 * separately based on the current TSF value. The hardware increments each
767 * timer by the beacon interval, when the local TSF converted to TU is equal
768 * to the value stored in the timer.
769 *
770 * The reception of a beacon with the same BSSID can update the local HW TSF
771 * at any time - this is something we can't avoid. If the TSF jumps to a
772 * time which is later than the time stored in a timer, this timer will not
773 * be updated until the TSF in TU wraps around at 16 bit (the size of the
774 * timers) and reaches the time which is stored in the timer.
775 *
776 * The problem is that these timers are closely related to TIMER0 (NBTT) and
777 * that they define a time "window". When the TSF jumps between two timers
778 * (e.g. ATIM and NBTT), the one in the past will be left behind (not
779 * updated), while the one in the future will be updated every beacon
780 * interval. This causes the window to get larger, until the TSF wraps
781 * around as described above and the timer which was left behind gets
782 * updated again. But - because the beacon interval is usually not an exact
783 * divisor of the size of the timers (16 bit), an unwanted "window" between
784 * these timers has developed!
785 *
786 * This is especially important with the ATIM window, because during
787 * the ATIM window only ATIM frames and no data frames are allowed to be
788 * sent, which creates transmission pauses after each beacon. This symptom
789 * has been described as "ramping ping" because ping times increase linearly
790 * for some time and then drop down again. A wrong window on the DMA beacon
791 * timer has the same effect, so we check for these two conditions.
792 *
793 * Returns true if O.K.
794 */
795 bool
796 ath5k_hw_check_beacon_timers(struct ath5k_hw *ah, int intval)
797 {
798 unsigned int nbtt, atim, dma;
799
800 nbtt = ath5k_hw_reg_read(ah, AR5K_TIMER0);
801 atim = ath5k_hw_reg_read(ah, AR5K_TIMER3);
802 dma = ath5k_hw_reg_read(ah, AR5K_TIMER1) >> 3;
803
804 /* NOTE: SWBA is different. Having a wrong window there does not
805 * stop us from sending data and this condition is caught by
806 * other means (SWBA interrupt) */
807
808 if (ath5k_check_timer_win(nbtt, atim, 1, intval) &&
809 ath5k_check_timer_win(dma, nbtt, AR5K_TUNE_DMA_BEACON_RESP,
810 intval))
811 return true; /* O.K. */
812 return false;
813 }
814
815 /**
816 * ath5k_hw_set_coverage_class() - Set IEEE 802.11 coverage class
817 * @ah: The &struct ath5k_hw
818 * @coverage_class: IEEE 802.11 coverage class number
819 *
820 * Sets IFS intervals and ACK/CTS timeouts for given coverage class.
821 */
822 void
823 ath5k_hw_set_coverage_class(struct ath5k_hw *ah, u8 coverage_class)
824 {
825 /* As defined by IEEE 802.11-2007 17.3.8.6 */
826 int slot_time = ath5k_hw_get_default_slottime(ah) + 3 * coverage_class;
827 int ack_timeout = ath5k_hw_get_default_sifs(ah) + slot_time;
828 int cts_timeout = ack_timeout;
829
830 ath5k_hw_set_ifs_intervals(ah, slot_time);
831 ath5k_hw_set_ack_timeout(ah, ack_timeout);
832 ath5k_hw_set_cts_timeout(ah, cts_timeout);
833
834 ah->ah_coverage_class = coverage_class;
835 }
836
837 /***************************\
838 * Init/Start/Stop functions *
839 \***************************/
840
841 /**
842 * ath5k_hw_start_rx_pcu() - Start RX engine
843 * @ah: The &struct ath5k_hw
844 *
845 * Starts RX engine on PCU so that hw can process RXed frames
846 * (ACK etc).
847 *
848 * NOTE: RX DMA should be already enabled using ath5k_hw_start_rx_dma
849 */
850 void
851 ath5k_hw_start_rx_pcu(struct ath5k_hw *ah)
852 {
853 AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
854 }
855
856 /**
857 * at5k_hw_stop_rx_pcu() - Stop RX engine
858 * @ah: The &struct ath5k_hw
859 *
860 * Stops RX engine on PCU
861 */
862 void
863 ath5k_hw_stop_rx_pcu(struct ath5k_hw *ah)
864 {
865 AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
866 }
867
868 /**
869 * ath5k_hw_set_opmode() - Set PCU operating mode
870 * @ah: The &struct ath5k_hw
871 * @op_mode: One of enum nl80211_iftype
872 *
873 * Configure PCU for the various operating modes (AP/STA etc)
874 */
875 int
876 ath5k_hw_set_opmode(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
877 {
878 struct ath_common *common = ath5k_hw_common(ah);
879 u32 pcu_reg, beacon_reg, low_id, high_id;
880
881 ATH5K_DBG(ah, ATH5K_DEBUG_MODE, "mode %d\n", op_mode);
882
883 /* Preserve rest settings */
884 pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
885 pcu_reg &= ~(AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_AP
886 | AR5K_STA_ID1_KEYSRCH_MODE
887 | (ah->ah_version == AR5K_AR5210 ?
888 (AR5K_STA_ID1_PWR_SV | AR5K_STA_ID1_NO_PSPOLL) : 0));
889
890 beacon_reg = 0;
891
892 switch (op_mode) {
893 case NL80211_IFTYPE_ADHOC:
894 pcu_reg |= AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_KEYSRCH_MODE;
895 beacon_reg |= AR5K_BCR_ADHOC;
896 if (ah->ah_version == AR5K_AR5210)
897 pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
898 else
899 AR5K_REG_ENABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
900 break;
901
902 case NL80211_IFTYPE_AP:
903 case NL80211_IFTYPE_MESH_POINT:
904 pcu_reg |= AR5K_STA_ID1_AP | AR5K_STA_ID1_KEYSRCH_MODE;
905 beacon_reg |= AR5K_BCR_AP;
906 if (ah->ah_version == AR5K_AR5210)
907 pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
908 else
909 AR5K_REG_DISABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
910 break;
911
912 case NL80211_IFTYPE_STATION:
913 pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
914 | (ah->ah_version == AR5K_AR5210 ?
915 AR5K_STA_ID1_PWR_SV : 0);
916 /* fall through */
917 case NL80211_IFTYPE_MONITOR:
918 pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
919 | (ah->ah_version == AR5K_AR5210 ?
920 AR5K_STA_ID1_NO_PSPOLL : 0);
921 break;
922
923 default:
924 return -EINVAL;
925 }
926
927 /*
928 * Set PCU registers
929 */
930 low_id = get_unaligned_le32(common->macaddr);
931 high_id = get_unaligned_le16(common->macaddr + 4);
932 ath5k_hw_reg_write(ah, low_id, AR5K_STA_ID0);
933 ath5k_hw_reg_write(ah, pcu_reg | high_id, AR5K_STA_ID1);
934
935 /*
936 * Set Beacon Control Register on 5210
937 */
938 if (ah->ah_version == AR5K_AR5210)
939 ath5k_hw_reg_write(ah, beacon_reg, AR5K_BCR);
940
941 return 0;
942 }
943
944 /**
945 * ath5k_hw_pcu_init() - Initialize PCU
946 * @ah: The &struct ath5k_hw
947 * @op_mode: One of enum nl80211_iftype
948 * @mode: One of enum ath5k_driver_mode
949 *
950 * This function is used to initialize PCU by setting current
951 * operation mode and various other settings.
952 */
953 void
954 ath5k_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, (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, 0x000100aa, AR5K_MIC_QOS_CTL);
986 ath5k_hw_reg_write(ah, 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, 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 }