2 * Copyright (c) 2008-2011 Atheros Communications Inc.
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 /* Calculate the modulo of a 64 bit TSF snapshot with a TU divisor */
22 static u32 ath9k_mod_tsf64_tu(u64 tsf, u32 div_tu)
24 u32 tsf_mod, tsf_hi, tsf_lo, mod_hi, mod_lo;
26 tsf_mod = tsf & (BIT(10) - 1);
28 tsf_lo = ((u32) tsf) >> 10;
30 mod_hi = tsf_hi % div_tu;
31 mod_lo = ((mod_hi << 22) + tsf_lo) % div_tu;
33 return (mod_lo << 10) | tsf_mod;
36 static u32 ath9k_get_next_tbtt(struct ath_hw *ah, u64 tsf,
37 unsigned int interval)
41 tsf += TU_TO_USEC(FUDGE + ah->config.sw_beacon_response_time);
42 offset = ath9k_mod_tsf64_tu(tsf, interval);
44 return (u32) tsf + TU_TO_USEC(interval) - offset;
48 * This sets up the beacon timers according to the timestamp of the last
49 * received beacon and the current TSF, configures PCF and DTIM
50 * handling, programs the sleep registers so the hardware will wakeup in
51 * time to receive beacons, and configures the beacon miss handling so
52 * we'll receive a BMISS interrupt when we stop seeing beacons from the AP
53 * we've associated with.
55 int ath9k_cmn_beacon_config_sta(struct ath_hw *ah,
56 struct ath_beacon_config *conf,
57 struct ath9k_beacon_state *bs)
59 struct ath_common *common = ath9k_hw_common(ah);
60 int dtim_intval, sleepduration;
63 /* No need to configure beacon if we are not associated */
64 if (!test_bit(ATH_OP_PRIM_STA_VIF, &common->op_flags)) {
65 ath_dbg(common, BEACON,
66 "STA is not yet associated..skipping beacon config\n");
70 memset(bs, 0, sizeof(*bs));
71 conf->intval = conf->beacon_interval;
74 * Setup dtim parameters according to
75 * last beacon we received (which may be none).
77 dtim_intval = conf->intval * conf->dtim_period;
78 sleepduration = ah->hw->conf.listen_interval * conf->intval;
81 * Pull nexttbtt forward to reflect the current
82 * TSF and calculate dtim state for the result.
84 tsf = ath9k_hw_gettsf64(ah);
85 conf->nexttbtt = ath9k_get_next_tbtt(ah, tsf, conf->intval);
87 bs->bs_intval = TU_TO_USEC(conf->intval);
88 bs->bs_dtimperiod = conf->dtim_period * bs->bs_intval;
89 bs->bs_nexttbtt = conf->nexttbtt;
90 bs->bs_nextdtim = conf->nexttbtt;
91 if (conf->dtim_period > 1)
92 bs->bs_nextdtim = ath9k_get_next_tbtt(ah, tsf, dtim_intval);
95 * Calculate the number of consecutive beacons to miss* before taking
96 * a BMISS interrupt. The configuration is specified in TU so we only
97 * need calculate based on the beacon interval. Note that we clamp the
98 * result to at most 15 beacons.
100 bs->bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, conf->intval);
101 if (bs->bs_bmissthreshold > 15)
102 bs->bs_bmissthreshold = 15;
103 else if (bs->bs_bmissthreshold <= 0)
104 bs->bs_bmissthreshold = 1;
107 * Calculate sleep duration. The configuration is given in ms.
108 * We ensure a multiple of the beacon period is used. Also, if the sleep
109 * duration is greater than the DTIM period then it makes senses
110 * to make it a multiple of that.
115 bs->bs_sleepduration = TU_TO_USEC(roundup(IEEE80211_MS_TO_TU(100),
117 if (bs->bs_sleepduration > bs->bs_dtimperiod)
118 bs->bs_sleepduration = bs->bs_dtimperiod;
120 /* TSF out of range threshold fixed at 1 second */
121 bs->bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
123 ath_dbg(common, BEACON, "bmiss: %u sleep: %u\n",
124 bs->bs_bmissthreshold, bs->bs_sleepduration);
127 EXPORT_SYMBOL(ath9k_cmn_beacon_config_sta);
129 void ath9k_cmn_beacon_config_adhoc(struct ath_hw *ah,
130 struct ath_beacon_config *conf)
132 struct ath_common *common = ath9k_hw_common(ah);
134 conf->intval = TU_TO_USEC(conf->beacon_interval);
136 if (conf->ibss_creator)
137 conf->nexttbtt = conf->intval;
139 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah),
140 conf->beacon_interval);
142 if (conf->enable_beacon)
143 ah->imask |= ATH9K_INT_SWBA;
145 ah->imask &= ~ATH9K_INT_SWBA;
147 ath_dbg(common, BEACON,
148 "IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
149 (conf->enable_beacon) ? "Enable" : "Disable",
150 conf->nexttbtt, conf->intval, conf->beacon_interval);
152 EXPORT_SYMBOL(ath9k_cmn_beacon_config_adhoc);
155 * For multi-bss ap support beacons are either staggered evenly over N slots or
156 * burst together. For the former arrange for the SWBA to be delivered for each
157 * slot. Slots that are not occupied will generate nothing.
159 void ath9k_cmn_beacon_config_ap(struct ath_hw *ah,
160 struct ath_beacon_config *conf,
163 struct ath_common *common = ath9k_hw_common(ah);
165 /* NB: the beacon interval is kept internally in TU's */
166 conf->intval = TU_TO_USEC(conf->beacon_interval);
167 conf->intval /= bc_buf;
168 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah),
169 conf->beacon_interval);
171 if (conf->enable_beacon)
172 ah->imask |= ATH9K_INT_SWBA;
174 ah->imask &= ~ATH9K_INT_SWBA;
176 ath_dbg(common, BEACON,
177 "AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
178 (conf->enable_beacon) ? "Enable" : "Disable",
179 conf->nexttbtt, conf->intval, conf->beacon_interval);
181 EXPORT_SYMBOL(ath9k_cmn_beacon_config_ap);