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
 21static 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 */
 41int 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}
112EXPORT_SYMBOL(ath9k_cmn_beacon_config_sta);
113
114void 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}
137EXPORT_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 */
144void 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}
166EXPORT_SYMBOL(ath9k_cmn_beacon_config_ap);