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 <linux/export.h>
18 #include "common.h"
19
20 #define FUDGE 2
21
ath9k_get_next_tbtt(struct ath_hw * ah,u64 tsf,unsigned int interval)22 static u32 ath9k_get_next_tbtt(struct ath_hw *ah, u64 tsf,
23 unsigned int interval)
24 {
25 unsigned int offset, divisor;
26
27 tsf += TU_TO_USEC(FUDGE + ah->config.sw_beacon_response_time);
28 divisor = TU_TO_USEC(interval);
29 div_u64_rem(tsf, divisor, &offset);
30
31 return (u32) tsf + divisor - offset;
32 }
33
34 /*
35 * This sets up the beacon timers according to the timestamp of the last
36 * received beacon and the current TSF, configures PCF and DTIM
37 * handling, programs the sleep registers so the hardware will wakeup in
38 * time to receive beacons, and configures the beacon miss handling so
39 * we'll receive a BMISS interrupt when we stop seeing beacons from the AP
40 * we've associated with.
41 */
ath9k_cmn_beacon_config_sta(struct ath_hw * ah,struct ath_beacon_config * conf,struct ath9k_beacon_state * bs)42 int ath9k_cmn_beacon_config_sta(struct ath_hw *ah,
43 struct ath_beacon_config *conf,
44 struct ath9k_beacon_state *bs)
45 {
46 struct ath_common *common = ath9k_hw_common(ah);
47 int dtim_intval;
48 u64 tsf;
49
50 /* No need to configure beacon if we are not associated */
51 if (!test_bit(ATH_OP_PRIM_STA_VIF, &common->op_flags)) {
52 ath_dbg(common, BEACON,
53 "STA is not yet associated..skipping beacon config\n");
54 return -EPERM;
55 }
56
57 memset(bs, 0, sizeof(*bs));
58 conf->intval = conf->beacon_interval;
59
60 /*
61 * Setup dtim parameters according to
62 * last beacon we received (which may be none).
63 */
64 dtim_intval = conf->intval * conf->dtim_period;
65
66 /*
67 * Pull nexttbtt forward to reflect the current
68 * TSF and calculate dtim state for the result.
69 */
70 tsf = ath9k_hw_gettsf64(ah);
71 conf->nexttbtt = ath9k_get_next_tbtt(ah, tsf, conf->intval);
72
73 bs->bs_intval = TU_TO_USEC(conf->intval);
74 bs->bs_dtimperiod = conf->dtim_period * bs->bs_intval;
75 bs->bs_nexttbtt = conf->nexttbtt;
76 bs->bs_nextdtim = conf->nexttbtt;
77 if (conf->dtim_period > 1)
78 bs->bs_nextdtim = ath9k_get_next_tbtt(ah, tsf, dtim_intval);
79
80 /*
81 * Calculate the number of consecutive beacons to miss* before taking
82 * a BMISS interrupt. The configuration is specified in TU so we only
83 * need calculate based on the beacon interval. Note that we clamp the
84 * result to at most 15 beacons.
85 */
86 bs->bs_bmissthreshold = DIV_ROUND_UP(conf->bmiss_timeout, conf->intval);
87 if (bs->bs_bmissthreshold > 15)
88 bs->bs_bmissthreshold = 15;
89 else if (bs->bs_bmissthreshold <= 0)
90 bs->bs_bmissthreshold = 1;
91
92 /*
93 * Calculate sleep duration. The configuration is given in ms.
94 * We ensure a multiple of the beacon period is used. Also, if the sleep
95 * duration is greater than the DTIM period then it makes senses
96 * to make it a multiple of that.
97 *
98 * XXX fixed at 100ms
99 */
100
101 bs->bs_sleepduration = TU_TO_USEC(roundup(IEEE80211_MS_TO_TU(100),
102 conf->intval));
103 if (bs->bs_sleepduration > bs->bs_dtimperiod)
104 bs->bs_sleepduration = bs->bs_dtimperiod;
105
106 /* TSF out of range threshold fixed at 1 second */
107 bs->bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
108
109 ath_dbg(common, BEACON, "bmiss: %u sleep: %u\n",
110 bs->bs_bmissthreshold, bs->bs_sleepduration);
111 return 0;
112 }
113 EXPORT_SYMBOL(ath9k_cmn_beacon_config_sta);
114
ath9k_cmn_beacon_config_adhoc(struct ath_hw * ah,struct ath_beacon_config * conf)115 void ath9k_cmn_beacon_config_adhoc(struct ath_hw *ah,
116 struct ath_beacon_config *conf)
117 {
118 struct ath_common *common = ath9k_hw_common(ah);
119
120 conf->intval = TU_TO_USEC(conf->beacon_interval);
121
122 if (conf->ibss_creator)
123 conf->nexttbtt = conf->intval;
124 else
125 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah),
126 conf->beacon_interval);
127
128 if (conf->enable_beacon)
129 ah->imask |= ATH9K_INT_SWBA;
130 else
131 ah->imask &= ~ATH9K_INT_SWBA;
132
133 ath_dbg(common, BEACON,
134 "IBSS (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
135 (conf->enable_beacon) ? "Enable" : "Disable",
136 conf->nexttbtt, conf->intval, conf->beacon_interval);
137 }
138 EXPORT_SYMBOL(ath9k_cmn_beacon_config_adhoc);
139
140 /*
141 * For multi-bss ap support beacons are either staggered evenly over N slots or
142 * burst together. For the former arrange for the SWBA to be delivered for each
143 * slot. Slots that are not occupied will generate nothing.
144 */
ath9k_cmn_beacon_config_ap(struct ath_hw * ah,struct ath_beacon_config * conf,unsigned int bc_buf)145 void ath9k_cmn_beacon_config_ap(struct ath_hw *ah,
146 struct ath_beacon_config *conf,
147 unsigned int bc_buf)
148 {
149 struct ath_common *common = ath9k_hw_common(ah);
150
151 /* NB: the beacon interval is kept internally in TU's */
152 conf->intval = TU_TO_USEC(conf->beacon_interval);
153 conf->intval /= bc_buf;
154 conf->nexttbtt = ath9k_get_next_tbtt(ah, ath9k_hw_gettsf64(ah),
155 conf->beacon_interval);
156
157 if (conf->enable_beacon)
158 ah->imask |= ATH9K_INT_SWBA;
159 else
160 ah->imask &= ~ATH9K_INT_SWBA;
161
162 ath_dbg(common, BEACON,
163 "AP (%s) nexttbtt: %u intval: %u conf_intval: %u\n",
164 (conf->enable_beacon) ? "Enable" : "Disable",
165 conf->nexttbtt, conf->intval, conf->beacon_interval);
166 }
167 EXPORT_SYMBOL(ath9k_cmn_beacon_config_ap);
168