1/*-
2 * Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * $FreeBSD$
26 */
27
28#ifndef _NET80211_IEEE80211_PHY_H_
29#define _NET80211_IEEE80211_PHY_H_
30
31#ifdef _KERNEL
32/*
33 * IEEE 802.11 PHY-related definitions.
34 */
35
36/*
37 * Contention window (slots).
38 */
39#define IEEE80211_CW_MAX	1023	/* aCWmax */
40#define IEEE80211_CW_MIN_0	31	/* DS/CCK aCWmin, ERP aCWmin(0) */
41#define IEEE80211_CW_MIN_1	15	/* OFDM aCWmin, ERP aCWmin(1) */
42
43/*
44 * SIFS (microseconds).
45 */
46#define IEEE80211_DUR_SIFS	10	/* DS/CCK/ERP SIFS */
47#define IEEE80211_DUR_OFDM_SIFS	16	/* OFDM SIFS */
48
49/*
50 * Slot time (microseconds).
51 */
52#define IEEE80211_DUR_SLOT	20	/* DS/CCK slottime, ERP long slottime */
53#define IEEE80211_DUR_SHSLOT	9	/* ERP short slottime */
54#define IEEE80211_DUR_OFDM_SLOT	9	/* OFDM slottime */
55
56/*
57 * DIFS (microseconds).
58 */
59#define IEEE80211_DUR_DIFS(sifs, slot)	((sifs) + 2 * (slot))
60
61struct ieee80211_channel;
62
63#define	IEEE80211_RATE_TABLE_SIZE	128
64
65struct ieee80211_rate_table {
66	int		rateCount;		/* NB: for proper padding */
67	uint8_t		rateCodeToIndex[256];	/* back mapping */
68	struct {
69		uint8_t		phy;		/* CCK/OFDM/TURBO */
70		uint32_t	rateKbps;	/* transfer rate in kbs */
71		uint8_t		shortPreamble;	/* mask for enabling short
72						 * preamble in CCK rate code */
73		uint8_t		dot11Rate;	/* value for supported rates
74						 * info element of MLME */
75		uint8_t		ctlRateIndex;	/* index of next lower basic
76						 * rate; used for dur. calcs */
77		uint16_t	lpAckDuration;	/* long preamble ACK dur. */
78		uint16_t	spAckDuration;	/* short preamble ACK dur. */
79	} info[IEEE80211_RATE_TABLE_SIZE];
80};
81
82const struct ieee80211_rate_table *ieee80211_get_ratetable(
83			struct ieee80211_channel *);
84
85static __inline__ uint8_t
86ieee80211_ack_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
87{
88	/*
89	 * XXX Assert this is for a legacy rate; not for an MCS rate.
90	 * If the caller wishes to use it for a basic rate, they should
91	 * clear the high bit first.
92	 */
93	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
94
95	uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
96	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
97	return rt->info[cix].dot11Rate;
98}
99
100static __inline__ uint8_t
101ieee80211_ctl_rate(const struct ieee80211_rate_table *rt, uint8_t rate)
102{
103	/*
104	 * XXX Assert this is for a legacy rate; not for an MCS rate.
105	 * If the caller wishes to use it for a basic rate, they should
106	 * clear the high bit first.
107	 */
108	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
109
110	uint8_t cix = rt->info[rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]].ctlRateIndex;
111	KASSERT(cix != (uint8_t)-1, ("rate %d has no info", rate));
112	return rt->info[cix].dot11Rate;
113}
114
115static __inline__ enum ieee80211_phytype
116ieee80211_rate2phytype(const struct ieee80211_rate_table *rt, uint8_t rate)
117{
118	/*
119	 * XXX Assert this is for a legacy rate; not for an MCS rate.
120	 * If the caller wishes to use it for a basic rate, they should
121	 * clear the high bit first.
122	 */
123	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
124
125	uint8_t rix = rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL];
126	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
127	return rt->info[rix].phy;
128}
129
130static __inline__ int
131ieee80211_isratevalid(const struct ieee80211_rate_table *rt, uint8_t rate)
132{
133	/*
134	 * XXX Assert this is for a legacy rate; not for an MCS rate.
135	 * If the caller wishes to use it for a basic rate, they should
136	 * clear the high bit first.
137	 */
138	KASSERT(! (rate & 0x80), ("rate %d is basic/mcs?", rate));
139
140	return rt->rateCodeToIndex[rate] != (uint8_t)-1;
141}
142
143/*
144 * Calculate ACK field for
145 * o  non-fragment data frames
146 * o  management frames
147 * sent using rate, phy and short preamble setting.
148 */
149static __inline__ uint16_t
150ieee80211_ack_duration(const struct ieee80211_rate_table *rt,
151    uint8_t rate, int isShortPreamble)
152{
153	uint8_t rix = rt->rateCodeToIndex[rate];
154
155	KASSERT(rix != (uint8_t)-1, ("rate %d has no info", rate));
156	if (isShortPreamble) {
157		KASSERT(rt->info[rix].spAckDuration != 0,
158			("shpreamble ack dur is not computed!\n"));
159		return rt->info[rix].spAckDuration;
160	} else {
161		KASSERT(rt->info[rix].lpAckDuration != 0,
162			("lgpreamble ack dur is not computed!\n"));
163		return rt->info[rix].lpAckDuration;
164	}
165}
166
167static __inline__ uint8_t
168ieee80211_legacy_rate_lookup(const struct ieee80211_rate_table *rt,
169    uint8_t rate)
170{
171
172	return (rt->rateCodeToIndex[rate & IEEE80211_RATE_VAL]);
173}
174
175/*
176 * Compute the time to transmit a frame of length frameLen bytes
177 * using the specified 802.11 rate code, phy, and short preamble
178 * setting.
179 *
180 * NB: SIFS is included.
181 */
182uint16_t	ieee80211_compute_duration(const struct ieee80211_rate_table *,
183			uint32_t frameLen, uint16_t rate, int isShortPreamble);
184/*
185 * Convert PLCP signal/rate field to 802.11 rate code (.5Mbits/s)
186 */
187uint8_t		ieee80211_plcp2rate(uint8_t, enum ieee80211_phytype);
188/*
189 * Convert 802.11 rate code to PLCP signal.
190 */
191uint8_t		ieee80211_rate2plcp(int, enum ieee80211_phytype);
192
193uint32_t	ieee80211_compute_duration_ht(uint32_t frameLen,
194			uint16_t rate, int streams, int isht40,
195			int isShortGI);
196
197#endif	/* _KERNEL */
198#endif	/* !_NET80211_IEEE80211_PHY_H_ */
199