xref: /freebsd/sys/dev/ath/if_ath_tsf.h (revision 3bdf775801b218aa5a89564839405b122f4b233e)
1 /*-
2  * Copyright (c) 2002-2009 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  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13  *    redistribution must be conditioned upon including a substantially
14  *    similar Disclaimer requirement for further binary redistribution.
15  *
16  * NO WARRANTY
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGES.
28  *
29  * $FreeBSD$
30  */
31 #ifndef	__IF_ATH_TSF_H__
32 #define	__IF_ATH_TSF_H__
33 
34 /*
35  * Extend 15-bit time stamp from rx descriptor to
36  * a full 64-bit TSF using the specified TSF.
37  */
38 static __inline u_int64_t
39 ath_extend_tsf15(u_int32_t rstamp, u_int64_t tsf)
40 {
41 	if ((tsf & 0x7fff) < rstamp)
42 		tsf -= 0x8000;
43 
44 	return ((tsf &~ 0x7fff) | rstamp);
45 }
46 
47 /*
48  * Extend 32-bit time stamp from rx descriptor to
49  * a full 64-bit TSF using the specified TSF.
50  */
51 static __inline u_int64_t
52 ath_extend_tsf32(u_int32_t rstamp, u_int64_t tsf)
53 {
54 	u_int32_t tsf_low = tsf & 0xffffffff;
55 	u_int64_t tsf64 = (tsf & ~0xffffffffULL) | rstamp;
56 
57 	if (rstamp > tsf_low && (rstamp - tsf_low > 0x10000000))
58 		tsf64 -= 0x100000000ULL;
59 
60 	if (rstamp < tsf_low && (tsf_low - rstamp > 0x10000000))
61 		tsf64 += 0x100000000ULL;
62 
63 	return tsf64;
64 }
65 
66 /*
67  * Extend the TSF from the RX descriptor to a full 64 bit TSF.
68  * Earlier hardware versions only wrote the low 15 bits of the
69  * TSF into the RX descriptor; later versions (AR5416 and up)
70  * include the 32 bit TSF value.
71  */
72 static __inline u_int64_t
73 ath_extend_tsf(struct ath_softc *sc, u_int32_t rstamp, u_int64_t tsf)
74 {
75 	if (sc->sc_rxtsf32)
76 		return ath_extend_tsf32(rstamp, tsf);
77 	else
78 		return ath_extend_tsf15(rstamp, tsf);
79 }
80 
81 #endif
82