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>
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.
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.
23 /*********************************\
24 * Protocol Control Unit Functions *
25 \*********************************/
27 #include <asm/unaligned.h>
39 * ath5k_hw_set_opmode - Set PCU operating mode
41 * @ah: The &struct ath5k_hw
42 * @op_mode: &enum nl80211_iftype operating mode
44 * Initialize PCU for the various operating modes (AP/STA etc)
46 int ath5k_hw_set_opmode(struct ath5k_hw
*ah
, enum nl80211_iftype op_mode
)
48 struct ath_common
*common
= ath5k_hw_common(ah
);
49 u32 pcu_reg
, beacon_reg
, low_id
, high_id
;
51 ATH5K_DBG(ah
->ah_sc
, ATH5K_DEBUG_MODE
, "mode %d\n", op_mode
);
53 /* Preserve rest settings */
54 pcu_reg
= ath5k_hw_reg_read(ah
, AR5K_STA_ID1
) & 0xffff0000;
55 pcu_reg
&= ~(AR5K_STA_ID1_ADHOC
| AR5K_STA_ID1_AP
56 | AR5K_STA_ID1_KEYSRCH_MODE
57 | (ah
->ah_version
== AR5K_AR5210
?
58 (AR5K_STA_ID1_PWR_SV
| AR5K_STA_ID1_NO_PSPOLL
) : 0));
63 case NL80211_IFTYPE_ADHOC
:
64 pcu_reg
|= AR5K_STA_ID1_ADHOC
| AR5K_STA_ID1_KEYSRCH_MODE
;
65 beacon_reg
|= AR5K_BCR_ADHOC
;
66 if (ah
->ah_version
== AR5K_AR5210
)
67 pcu_reg
|= AR5K_STA_ID1_NO_PSPOLL
;
69 AR5K_REG_ENABLE_BITS(ah
, AR5K_CFG
, AR5K_CFG_IBSS
);
72 case NL80211_IFTYPE_AP
:
73 case NL80211_IFTYPE_MESH_POINT
:
74 pcu_reg
|= AR5K_STA_ID1_AP
| AR5K_STA_ID1_KEYSRCH_MODE
;
75 beacon_reg
|= AR5K_BCR_AP
;
76 if (ah
->ah_version
== AR5K_AR5210
)
77 pcu_reg
|= AR5K_STA_ID1_NO_PSPOLL
;
79 AR5K_REG_DISABLE_BITS(ah
, AR5K_CFG
, AR5K_CFG_IBSS
);
82 case NL80211_IFTYPE_STATION
:
83 pcu_reg
|= AR5K_STA_ID1_KEYSRCH_MODE
84 | (ah
->ah_version
== AR5K_AR5210
?
85 AR5K_STA_ID1_PWR_SV
: 0);
86 case NL80211_IFTYPE_MONITOR
:
87 pcu_reg
|= AR5K_STA_ID1_KEYSRCH_MODE
88 | (ah
->ah_version
== AR5K_AR5210
?
89 AR5K_STA_ID1_NO_PSPOLL
: 0);
99 low_id
= get_unaligned_le32(common
->macaddr
);
100 high_id
= get_unaligned_le16(common
->macaddr
+ 4);
101 ath5k_hw_reg_write(ah
, low_id
, AR5K_STA_ID0
);
102 ath5k_hw_reg_write(ah
, pcu_reg
| high_id
, AR5K_STA_ID1
);
105 * Set Beacon Control Register on 5210
107 if (ah
->ah_version
== AR5K_AR5210
)
108 ath5k_hw_reg_write(ah
, beacon_reg
, AR5K_BCR
);
114 * ath5k_hw_update - Update MIB counters (mac layer statistics)
116 * @ah: The &struct ath5k_hw
118 * Reads MIB counters from PCU and updates sw statistics. Is called after a
119 * MIB interrupt, because one of these counters might have reached their maximum
120 * and triggered the MIB interrupt, to let us read and clear the counter.
122 * Is called in interrupt context!
124 void ath5k_hw_update_mib_counters(struct ath5k_hw
*ah
)
126 struct ath5k_statistics
*stats
= &ah
->ah_sc
->stats
;
129 stats
->ack_fail
+= ath5k_hw_reg_read(ah
, AR5K_ACK_FAIL
);
130 stats
->rts_fail
+= ath5k_hw_reg_read(ah
, AR5K_RTS_FAIL
);
131 stats
->rts_ok
+= ath5k_hw_reg_read(ah
, AR5K_RTS_OK
);
132 stats
->fcs_error
+= ath5k_hw_reg_read(ah
, AR5K_FCS_FAIL
);
133 stats
->beacons
+= ath5k_hw_reg_read(ah
, AR5K_BEACON_CNT
);
137 * ath5k_hw_set_ack_bitrate - set bitrate for ACKs
139 * @ah: The &struct ath5k_hw
140 * @high: Flag to determine if we want to use high transmission rate
143 * If high flag is set, we tell hw to use a set of control rates based on
144 * the current transmission rate (check out control_rates array inside reset.c).
145 * If not hw just uses the lowest rate available for the current modulation
146 * scheme being used (1Mbit for CCK and 6Mbits for OFDM).
148 void ath5k_hw_set_ack_bitrate_high(struct ath5k_hw
*ah
, bool high
)
150 if (ah
->ah_version
!= AR5K_AR5212
)
153 u32 val
= AR5K_STA_ID1_BASE_RATE_11B
| AR5K_STA_ID1_ACKCTS_6MB
;
155 AR5K_REG_DISABLE_BITS(ah
, AR5K_STA_ID1
, val
);
157 AR5K_REG_ENABLE_BITS(ah
, AR5K_STA_ID1
, val
);
167 * ath5k_hw_set_ack_timeout - Set ACK timeout on PCU
169 * @ah: The &struct ath5k_hw
170 * @timeout: Timeout in usec
172 static int ath5k_hw_set_ack_timeout(struct ath5k_hw
*ah
, unsigned int timeout
)
174 if (ath5k_hw_clocktoh(ah
, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK
))
178 AR5K_REG_WRITE_BITS(ah
, AR5K_TIME_OUT
, AR5K_TIME_OUT_ACK
,
179 ath5k_hw_htoclock(ah
, timeout
));
185 * ath5k_hw_set_cts_timeout - Set CTS timeout on PCU
187 * @ah: The &struct ath5k_hw
188 * @timeout: Timeout in usec
190 static int ath5k_hw_set_cts_timeout(struct ath5k_hw
*ah
, unsigned int timeout
)
192 if (ath5k_hw_clocktoh(ah
, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS
))
196 AR5K_REG_WRITE_BITS(ah
, AR5K_TIME_OUT
, AR5K_TIME_OUT_CTS
,
197 ath5k_hw_htoclock(ah
, timeout
));
203 * ath5k_hw_htoclock - Translate usec to hw clock units
205 * @ah: The &struct ath5k_hw
206 * @usec: value in microseconds
208 unsigned int ath5k_hw_htoclock(struct ath5k_hw
*ah
, unsigned int usec
)
210 return usec
* ath5k_hw_get_clockrate(ah
);
214 * ath5k_hw_clocktoh - Translate hw clock units to usec
215 * @clock: value in hw clock units
217 unsigned int ath5k_hw_clocktoh(struct ath5k_hw
*ah
, unsigned int clock
)
219 return clock
/ ath5k_hw_get_clockrate(ah
);
223 * ath5k_hw_get_clockrate - Get the clock rate for current mode
225 * @ah: The &struct ath5k_hw
227 unsigned int ath5k_hw_get_clockrate(struct ath5k_hw
*ah
)
229 struct ieee80211_channel
*channel
= ah
->ah_current_channel
;
232 if (channel
->hw_value
& CHANNEL_5GHZ
)
233 clock
= 40; /* 802.11a */
234 else if (channel
->hw_value
& CHANNEL_CCK
)
235 clock
= 22; /* 802.11b */
237 clock
= 44; /* 802.11g */
239 /* Clock rate in turbo modes is twice the normal rate */
240 if (channel
->hw_value
& CHANNEL_TURBO
)
247 * ath5k_hw_get_default_slottime - Get the default slot time for current mode
249 * @ah: The &struct ath5k_hw
251 static unsigned int ath5k_hw_get_default_slottime(struct ath5k_hw
*ah
)
253 struct ieee80211_channel
*channel
= ah
->ah_current_channel
;
255 if (channel
->hw_value
& CHANNEL_TURBO
)
256 return 6; /* both turbo modes */
258 if (channel
->hw_value
& CHANNEL_CCK
)
259 return 20; /* 802.11b */
261 return 9; /* 802.11 a/g */
265 * ath5k_hw_get_default_sifs - Get the default SIFS for current mode
267 * @ah: The &struct ath5k_hw
269 static unsigned int ath5k_hw_get_default_sifs(struct ath5k_hw
*ah
)
271 struct ieee80211_channel
*channel
= ah
->ah_current_channel
;
273 if (channel
->hw_value
& CHANNEL_TURBO
)
274 return 8; /* both turbo modes */
276 if (channel
->hw_value
& CHANNEL_5GHZ
)
277 return 16; /* 802.11a */
279 return 10; /* 802.11 b/g */
283 * ath5k_hw_set_lladdr - Set station id
285 * @ah: The &struct ath5k_hw
286 * @mac: The card's mac address
288 * Set station id on hw using the provided mac address
290 int ath5k_hw_set_lladdr(struct ath5k_hw
*ah
, const u8
*mac
)
292 struct ath_common
*common
= ath5k_hw_common(ah
);
296 /* Set new station ID */
297 memcpy(common
->macaddr
, mac
, ETH_ALEN
);
299 pcu_reg
= ath5k_hw_reg_read(ah
, AR5K_STA_ID1
) & 0xffff0000;
301 low_id
= get_unaligned_le32(mac
);
302 high_id
= get_unaligned_le16(mac
+ 4);
304 ath5k_hw_reg_write(ah
, low_id
, AR5K_STA_ID0
);
305 ath5k_hw_reg_write(ah
, pcu_reg
| high_id
, AR5K_STA_ID1
);
311 * ath5k_hw_set_bssid - Set current BSSID on hw
313 * @ah: The &struct ath5k_hw
315 * Sets the current BSSID and BSSID mask we have from the
316 * common struct into the hardware
318 void ath5k_hw_set_bssid(struct ath5k_hw
*ah
)
320 struct ath_common
*common
= ath5k_hw_common(ah
);
324 * Set BSSID mask on 5212
326 if (ah
->ah_version
== AR5K_AR5212
)
327 ath_hw_setbssidmask(common
);
332 ath5k_hw_reg_write(ah
,
333 get_unaligned_le32(common
->curbssid
),
335 ath5k_hw_reg_write(ah
,
336 get_unaligned_le16(common
->curbssid
+ 4) |
337 ((common
->curaid
& 0x3fff) << AR5K_BSS_ID1_AID_S
),
340 if (common
->curaid
== 0) {
341 ath5k_hw_disable_pspoll(ah
);
345 AR5K_REG_WRITE_BITS(ah
, AR5K_BEACON
, AR5K_BEACON_TIM
,
346 tim_offset
? tim_offset
+ 4 : 0);
348 ath5k_hw_enable_pspoll(ah
, NULL
, 0);
351 void ath5k_hw_set_bssid_mask(struct ath5k_hw
*ah
, const u8
*mask
)
353 struct ath_common
*common
= ath5k_hw_common(ah
);
355 /* Cache bssid mask so that we can restore it
357 memcpy(common
->bssidmask
, mask
, ETH_ALEN
);
358 if (ah
->ah_version
== AR5K_AR5212
)
359 ath_hw_setbssidmask(common
);
367 * ath5k_hw_start_rx_pcu - Start RX engine
369 * @ah: The &struct ath5k_hw
371 * Starts RX engine on PCU so that hw can process RXed frames
374 * NOTE: RX DMA should be already enabled using ath5k_hw_start_rx_dma
376 void ath5k_hw_start_rx_pcu(struct ath5k_hw
*ah
)
378 AR5K_REG_DISABLE_BITS(ah
, AR5K_DIAG_SW
, AR5K_DIAG_SW_DIS_RX
);
382 * at5k_hw_stop_rx_pcu - Stop RX engine
384 * @ah: The &struct ath5k_hw
386 * Stops RX engine on PCU
388 * TODO: Detach ANI here
390 void ath5k_hw_stop_rx_pcu(struct ath5k_hw
*ah
)
392 AR5K_REG_ENABLE_BITS(ah
, AR5K_DIAG_SW
, AR5K_DIAG_SW_DIS_RX
);
396 * Set multicast filter
398 void ath5k_hw_set_mcast_filter(struct ath5k_hw
*ah
, u32 filter0
, u32 filter1
)
400 ath5k_hw_reg_write(ah
, filter0
, AR5K_MCAST_FILTER0
);
401 ath5k_hw_reg_write(ah
, filter1
, AR5K_MCAST_FILTER1
);
405 * ath5k_hw_get_rx_filter - Get current rx filter
407 * @ah: The &struct ath5k_hw
409 * Returns the RX filter by reading rx filter and
410 * phy error filter registers. RX filter is used
411 * to set the allowed frame types that PCU will accept
412 * and pass to the driver. For a list of frame types
415 u32
ath5k_hw_get_rx_filter(struct ath5k_hw
*ah
)
417 u32 data
, filter
= 0;
419 filter
= ath5k_hw_reg_read(ah
, AR5K_RX_FILTER
);
421 /*Radar detection for 5212*/
422 if (ah
->ah_version
== AR5K_AR5212
) {
423 data
= ath5k_hw_reg_read(ah
, AR5K_PHY_ERR_FIL
);
425 if (data
& AR5K_PHY_ERR_FIL_RADAR
)
426 filter
|= AR5K_RX_FILTER_RADARERR
;
427 if (data
& (AR5K_PHY_ERR_FIL_OFDM
| AR5K_PHY_ERR_FIL_CCK
))
428 filter
|= AR5K_RX_FILTER_PHYERR
;
435 * ath5k_hw_set_rx_filter - Set rx filter
437 * @ah: The &struct ath5k_hw
438 * @filter: RX filter mask (see reg.h)
440 * Sets RX filter register and also handles PHY error filter
441 * register on 5212 and newer chips so that we have proper PHY
444 void ath5k_hw_set_rx_filter(struct ath5k_hw
*ah
, u32 filter
)
448 /* Set PHY error filter register on 5212*/
449 if (ah
->ah_version
== AR5K_AR5212
) {
450 if (filter
& AR5K_RX_FILTER_RADARERR
)
451 data
|= AR5K_PHY_ERR_FIL_RADAR
;
452 if (filter
& AR5K_RX_FILTER_PHYERR
)
453 data
|= AR5K_PHY_ERR_FIL_OFDM
| AR5K_PHY_ERR_FIL_CCK
;
457 * The AR5210 uses promiscous mode to detect radar activity
459 if (ah
->ah_version
== AR5K_AR5210
&&
460 (filter
& AR5K_RX_FILTER_RADARERR
)) {
461 filter
&= ~AR5K_RX_FILTER_RADARERR
;
462 filter
|= AR5K_RX_FILTER_PROM
;
465 /*Zero length DMA (phy error reporting) */
467 AR5K_REG_ENABLE_BITS(ah
, AR5K_RXCFG
, AR5K_RXCFG_ZLFDMA
);
469 AR5K_REG_DISABLE_BITS(ah
, AR5K_RXCFG
, AR5K_RXCFG_ZLFDMA
);
471 /*Write RX Filter register*/
472 ath5k_hw_reg_write(ah
, filter
& 0xff, AR5K_RX_FILTER
);
474 /*Write PHY error filter register on 5212*/
475 if (ah
->ah_version
== AR5K_AR5212
)
476 ath5k_hw_reg_write(ah
, data
, AR5K_PHY_ERR_FIL
);
485 #define ATH5K_MAX_TSF_READ 10
488 * ath5k_hw_get_tsf64 - Get the full 64bit TSF
490 * @ah: The &struct ath5k_hw
492 * Returns the current TSF
494 u64
ath5k_hw_get_tsf64(struct ath5k_hw
*ah
)
496 u32 tsf_lower
, tsf_upper1
, tsf_upper2
;
500 /* This code is time critical - we don't want to be interrupted here */
501 local_irq_save(flags
);
504 * While reading TSF upper and then lower part, the clock is still
505 * counting (or jumping in case of IBSS merge) so we might get
506 * inconsistent values. To avoid this, we read the upper part again
507 * and check it has not been changed. We make the hypothesis that a
508 * maximum of 3 changes can happens in a row (we use 10 as a safe
511 * Impact on performance is pretty small, since in most cases, only
512 * 3 register reads are needed.
515 tsf_upper1
= ath5k_hw_reg_read(ah
, AR5K_TSF_U32
);
516 for (i
= 0; i
< ATH5K_MAX_TSF_READ
; i
++) {
517 tsf_lower
= ath5k_hw_reg_read(ah
, AR5K_TSF_L32
);
518 tsf_upper2
= ath5k_hw_reg_read(ah
, AR5K_TSF_U32
);
519 if (tsf_upper2
== tsf_upper1
)
521 tsf_upper1
= tsf_upper2
;
524 local_irq_restore(flags
);
526 WARN_ON( i
== ATH5K_MAX_TSF_READ
);
528 return (((u64
)tsf_upper1
<< 32) | tsf_lower
);
532 * ath5k_hw_set_tsf64 - Set a new 64bit TSF
534 * @ah: The &struct ath5k_hw
535 * @tsf64: The new 64bit TSF
539 void ath5k_hw_set_tsf64(struct ath5k_hw
*ah
, u64 tsf64
)
541 ath5k_hw_reg_write(ah
, tsf64
& 0xffffffff, AR5K_TSF_L32
);
542 ath5k_hw_reg_write(ah
, (tsf64
>> 32) & 0xffffffff, AR5K_TSF_U32
);
546 * ath5k_hw_reset_tsf - Force a TSF reset
548 * @ah: The &struct ath5k_hw
550 * Forces a TSF reset on PCU
552 void ath5k_hw_reset_tsf(struct ath5k_hw
*ah
)
556 val
= ath5k_hw_reg_read(ah
, AR5K_BEACON
) | AR5K_BEACON_RESET_TSF
;
559 * Each write to the RESET_TSF bit toggles a hardware internal
560 * signal to reset TSF, but if left high it will cause a TSF reset
561 * on the next chip reset as well. Thus we always write the value
562 * twice to clear the signal.
564 ath5k_hw_reg_write(ah
, val
, AR5K_BEACON
);
565 ath5k_hw_reg_write(ah
, val
, AR5K_BEACON
);
569 * Initialize beacon timers
571 void ath5k_hw_init_beacon(struct ath5k_hw
*ah
, u32 next_beacon
, u32 interval
)
573 u32 timer1
, timer2
, timer3
;
576 * Set the additional timers by mode
578 switch (ah
->ah_sc
->opmode
) {
579 case NL80211_IFTYPE_MONITOR
:
580 case NL80211_IFTYPE_STATION
:
581 /* In STA mode timer1 is used as next wakeup
582 * timer and timer2 as next CFP duration start
583 * timer. Both in 1/8TUs. */
584 /* TODO: PCF handling */
585 if (ah
->ah_version
== AR5K_AR5210
) {
592 /* Mark associated AP as PCF incapable for now */
593 AR5K_REG_DISABLE_BITS(ah
, AR5K_STA_ID1
, AR5K_STA_ID1_PCF
);
595 case NL80211_IFTYPE_ADHOC
:
596 AR5K_REG_ENABLE_BITS(ah
, AR5K_TXCFG
, AR5K_TXCFG_ADHOC_BCN_ATIM
);
598 /* On non-STA modes timer1 is used as next DMA
599 * beacon alert (DBA) timer and timer2 as next
600 * software beacon alert. Both in 1/8TUs. */
601 timer1
= (next_beacon
- AR5K_TUNE_DMA_BEACON_RESP
) << 3;
602 timer2
= (next_beacon
- AR5K_TUNE_SW_BEACON_RESP
) << 3;
606 /* Timer3 marks the end of our ATIM window
607 * a zero length window is not allowed because
608 * we 'll get no beacons */
609 timer3
= next_beacon
+ 1;
612 * Set the beacon register and enable all timers.
614 /* When in AP or Mesh Point mode zero timer0 to start TSF */
615 if (ah
->ah_sc
->opmode
== NL80211_IFTYPE_AP
||
616 ah
->ah_sc
->opmode
== NL80211_IFTYPE_MESH_POINT
)
617 ath5k_hw_reg_write(ah
, 0, AR5K_TIMER0
);
619 ath5k_hw_reg_write(ah
, next_beacon
, AR5K_TIMER0
);
620 ath5k_hw_reg_write(ah
, timer1
, AR5K_TIMER1
);
621 ath5k_hw_reg_write(ah
, timer2
, AR5K_TIMER2
);
622 ath5k_hw_reg_write(ah
, timer3
, AR5K_TIMER3
);
624 /* Force a TSF reset if requested and enable beacons */
625 if (interval
& AR5K_BEACON_RESET_TSF
)
626 ath5k_hw_reset_tsf(ah
);
628 ath5k_hw_reg_write(ah
, interval
& (AR5K_BEACON_PERIOD
|
632 /* Flush any pending BMISS interrupts on ISR by
633 * performing a clear-on-write operation on PISR
634 * register for the BMISS bit (writing a bit on
635 * ISR togles a reset for that bit and leaves
636 * the rest bits intact) */
637 if (ah
->ah_version
== AR5K_AR5210
)
638 ath5k_hw_reg_write(ah
, AR5K_ISR_BMISS
, AR5K_ISR
);
640 ath5k_hw_reg_write(ah
, AR5K_ISR_BMISS
, AR5K_PISR
);
642 /* TODO: Set enchanced sleep registers on AR5212
643 * based on vif->bss_conf params, until then
644 * disable power save reporting.*/
645 AR5K_REG_DISABLE_BITS(ah
, AR5K_STA_ID1
, AR5K_STA_ID1_PWR_SV
);
650 * ath5k_check_timer_win - Check if timer B is timer A + window
652 * @a: timer a (before b)
653 * @b: timer b (after a)
654 * @window: difference between a and b
655 * @intval: timers are increased by this interval
657 * This helper function checks if timer B is timer A + window and covers
658 * cases where timer A or B might have already been updated or wrapped
659 * around (Timers are 16 bit).
661 * Returns true if O.K.
664 ath5k_check_timer_win(int a
, int b
, int window
, int intval
)
667 * 1.) usually B should be A + window
668 * 2.) A already updated, B not updated yet
669 * 3.) A already updated and has wrapped around
670 * 4.) B has wrapped around
672 if ((b
- a
== window
) || /* 1.) */
673 (a
- b
== intval
- window
) || /* 2.) */
674 ((a
| 0x10000) - b
== intval
- window
) || /* 3.) */
675 ((b
| 0x10000) - a
== window
)) /* 4.) */
676 return true; /* O.K. */
681 * ath5k_hw_check_beacon_timers - Check if the beacon timers are correct
683 * @ah: The &struct ath5k_hw
684 * @intval: beacon interval
686 * This is a workaround for IBSS mode:
688 * The need for this function arises from the fact that we have 4 separate
689 * HW timer registers (TIMER0 - TIMER3), which are closely related to the
690 * next beacon target time (NBTT), and that the HW updates these timers
691 * seperately based on the current TSF value. The hardware increments each
692 * timer by the beacon interval, when the local TSF coverted to TU is equal
693 * to the value stored in the timer.
695 * The reception of a beacon with the same BSSID can update the local HW TSF
696 * at any time - this is something we can't avoid. If the TSF jumps to a
697 * time which is later than the time stored in a timer, this timer will not
698 * be updated until the TSF in TU wraps around at 16 bit (the size of the
699 * timers) and reaches the time which is stored in the timer.
701 * The problem is that these timers are closely related to TIMER0 (NBTT) and
702 * that they define a time "window". When the TSF jumps between two timers
703 * (e.g. ATIM and NBTT), the one in the past will be left behind (not
704 * updated), while the one in the future will be updated every beacon
705 * interval. This causes the window to get larger, until the TSF wraps
706 * around as described above and the timer which was left behind gets
707 * updated again. But - because the beacon interval is usually not an exact
708 * divisor of the size of the timers (16 bit), an unwanted "window" between
709 * these timers has developed!
711 * This is especially important with the ATIM window, because during
712 * the ATIM window only ATIM frames and no data frames are allowed to be
713 * sent, which creates transmission pauses after each beacon. This symptom
714 * has been described as "ramping ping" because ping times increase linearly
715 * for some time and then drop down again. A wrong window on the DMA beacon
716 * timer has the same effect, so we check for these two conditions.
718 * Returns true if O.K.
721 ath5k_hw_check_beacon_timers(struct ath5k_hw
*ah
, int intval
)
723 unsigned int nbtt
, atim
, dma
;
725 nbtt
= ath5k_hw_reg_read(ah
, AR5K_TIMER0
);
726 atim
= ath5k_hw_reg_read(ah
, AR5K_TIMER3
);
727 dma
= ath5k_hw_reg_read(ah
, AR5K_TIMER1
) >> 3;
729 /* NOTE: SWBA is different. Having a wrong window there does not
730 * stop us from sending data and this condition is catched thru
731 * other means (SWBA interrupt) */
733 if (ath5k_check_timer_win(nbtt
, atim
, 1, intval
) &&
734 ath5k_check_timer_win(dma
, nbtt
, AR5K_TUNE_DMA_BEACON_RESP
,
736 return true; /* O.K. */
741 * ath5k_hw_set_coverage_class - Set IEEE 802.11 coverage class
743 * @ah: The &struct ath5k_hw
744 * @coverage_class: IEEE 802.11 coverage class number
746 * Sets slot time, ACK timeout and CTS timeout for given coverage class.
748 void ath5k_hw_set_coverage_class(struct ath5k_hw
*ah
, u8 coverage_class
)
750 /* As defined by IEEE 802.11-2007 17.3.8.6 */
751 int slot_time
= ath5k_hw_get_default_slottime(ah
) + 3 * coverage_class
;
752 int ack_timeout
= ath5k_hw_get_default_sifs(ah
) + slot_time
;
753 int cts_timeout
= ack_timeout
;
755 ath5k_hw_set_slot_time(ah
, slot_time
);
756 ath5k_hw_set_ack_timeout(ah
, ack_timeout
);
757 ath5k_hw_set_cts_timeout(ah
, cts_timeout
);
759 ah
->ah_coverage_class
= coverage_class
;