1 /* 2 * Copyright (c) 2008-2011 Atheros Communications Inc. 3 * 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. 7 * 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. 15 */ 16 17 #include "common.h" 18 19 #define FUDGE 2 20 21 static u32 ath9k_get_next_tbtt(struct ath_hw *ah, u64 tsf, 22 unsigned int interval) 23 { 24 unsigned int offset, divisor; 25 26 tsf += TU_TO_USEC(FUDGE + ah->config.sw_beacon_response_time); 27 divisor = TU_TO_USEC(interval); 28 div_u64_rem(tsf, divisor, &offset); 29 30 return (u32) tsf + divisor - offset; 31 } 32 33 /* 34 * This sets up the beacon timers according to the timestamp of the last 35 * received beacon and the current TSF, configures PCF and DTIM 36 * handling, programs the sleep registers so the hardware will wakeup in 37 * time to receive beacons, and configures the beacon miss handling so 38 * we'll receive a BMISS interrupt when we stop seeing beacons from the AP 39 * we've associated with. 40 */ 41 int ath9k_cmn_beacon_config_sta(struct ath_hw *ah, 42 struct ath_beacon_config *conf, 43 struct ath9k_beacon_state *bs) 44 { 45 struct ath_common *common = ath9k_hw_common(ah); 46 int dtim_intval; 47 u64 tsf; 48 49 /* No need to configure beacon if we are not associated */ 50 if (!test_bit(ATH_OP_PRIM_STA_VIF, &common->op_flags)) { 51 ath_dbg(common, BEACON, 52 "STA is not yet associated..skipping beacon config\n"); 53 return -EPERM; 54 } 55 56 memset(bs, 0, sizeof(*bs)); 57 conf->intval = conf->beacon_interval; 58 59 /* 60 * Setup dtim parameters according to 61 * last beacon we received (which may be none). 62 */ 63 dtim_intval = conf->intval * conf->dtim_period; 64 65 /* 66 * Pull nexttbtt forward to reflect the current 67 * TSF and calculate dtim state for the result. 68 */ 69 tsf = ath9k_hw_gettsf64(ah); 70 conf->nexttbtt = ath9k_get_next_tbtt(ah, tsf, conf->intval); 71 72 bs->bs_intval = TU_TO_USEC(conf->intval); 73 bs->bs_dtimperiod = conf->dtim_period * bs->bs_intval; 74 bs->bs_nexttbtt = conf->nexttbtt; 75 bs->bs_nextdtim = conf->nexttbtt; 76 if (conf->dtim_period > 1) 77 bs->bs_nextdtim = ath9k_get_next_tbtt(ah, tsf, dtim_intval); 78 79 /* 80 * Calculate the number of consecutive beacons to miss* before taking 81 * a BMISS interrupt. The configuration is specified in TU so we only 82 * need calculate based on the beacon interval. Note that we clamp the 83 * result to at most 15 beacons. 84 */ 85 bs->bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, conf->intval); 86 if (bs->bs_bmissthreshold > 15) 87 bs->bs_bmissthreshold = 15; 88 else if (bs->bs_bmissthreshold <= 0) 89 bs->bs_bmissthreshold = 1; 90 91 /* 92 * Calculate sleep duration. The configuration is given in ms. 93 * We ensure a multiple of the beacon period is used. Also, if the sleep 94 * duration is greater than the DTIM period then it makes senses 95 * to make it a multiple of that. 96 * 97 * XXX fixed at 100ms 98 */ 99 100 bs->bs_sleepduration = TU_TO_USEC(roundup(IEEE80211_MS_TO_TU(100), 101 conf->intval)); 102 if (bs->bs_sleepduration > bs->bs_dtimperiod) 103 bs->bs_sleepduration = bs->bs_dtimperiod; 104 105 /* TSF out of range threshold fixed at 1 second */ 106 bs->bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD; 107 108 ath_dbg(common, BEACON, "bmiss: %u sleep: %u\n", 109 bs->bs_bmissthreshold, bs->bs_sleepduration); 110 return 0; 111 } 112 EXPORT_SYMBOL(ath9k_cmn_beacon_config_sta); 113 114 void ath9k_cmn_beacon_config_adhoc(struct ath_hw *ah, 115 struct ath_beacon_config *conf) 116 { 117 struct ath_common *common = ath9k_hw_common(ah); 118 119 conf->intval = TU_TO_USEC(conf->beacon_interval); 120 121 if (conf->ibss_creator) 122 conf->nexttbtt = conf->intval; 123 else 124 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah), 125 conf->beacon_interval); 126 127 if (conf->enable_beacon) 128 ah->imask |= ATH9K_INT_SWBA; 129 else 130 ah->imask &= ~ATH9K_INT_SWBA; 131 132 ath_dbg(common, BEACON, 133 "IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n", 134 (conf->enable_beacon) ? "Enable" : "Disable", 135 conf->nexttbtt, conf->intval, conf->beacon_interval); 136 } 137 EXPORT_SYMBOL(ath9k_cmn_beacon_config_adhoc); 138 139 /* 140 * For multi-bss ap support beacons are either staggered evenly over N slots or 141 * burst together. For the former arrange for the SWBA to be delivered for each 142 * slot. Slots that are not occupied will generate nothing. 143 */ 144 void ath9k_cmn_beacon_config_ap(struct ath_hw *ah, 145 struct ath_beacon_config *conf, 146 unsigned int bc_buf) 147 { 148 struct ath_common *common = ath9k_hw_common(ah); 149 150 /* NB: the beacon interval is kept internally in TU's */ 151 conf->intval = TU_TO_USEC(conf->beacon_interval); 152 conf->intval /= bc_buf; 153 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah), 154 conf->beacon_interval); 155 156 if (conf->enable_beacon) 157 ah->imask |= ATH9K_INT_SWBA; 158 else 159 ah->imask &= ~ATH9K_INT_SWBA; 160 161 ath_dbg(common, BEACON, 162 "AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n", 163 (conf->enable_beacon) ? "Enable" : "Disable", 164 conf->nexttbtt, conf->intval, conf->beacon_interval); 165 } 166 EXPORT_SYMBOL(ath9k_cmn_beacon_config_ap); 167