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
ath9k_get_next_tbtt(struct ath_hw * ah,u64 tsf,unsigned int interval)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 */
ath9k_cmn_beacon_config_sta(struct ath_hw * ah,struct ath_beacon_config * conf,struct ath9k_beacon_state * bs)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
ath9k_cmn_beacon_config_adhoc(struct ath_hw * ah,struct ath_beacon_config * conf)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 */
ath9k_cmn_beacon_config_ap(struct ath_hw * ah,struct ath_beacon_config * conf,unsigned int bc_buf)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