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(dividend: tsf, divisor, remainder: &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, interval: 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, interval: 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, tsf: ath9k_hw_gettsf64(ah), |
125 | interval: 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, tsf: ath9k_hw_gettsf64(ah), |
154 | interval: 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 | |