xref: /freebsd/sys/dev/ath/if_ath_tsf.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
15  *    redistribution must be conditioned upon including a substantially
16  *    similar Disclaimer requirement for further binary redistribution.
17  *
18  * NO WARRANTY
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
24  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
27  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
29  * THE POSSIBILITY OF SUCH DAMAGES.
30  *
31  * $FreeBSD$
32  */
33 #ifndef	__IF_ATH_TSF_H__
34 #define	__IF_ATH_TSF_H__
35 
36 /*
37  * Extend 15-bit time stamp from rx descriptor to
38  * a full 64-bit TSF using the specified TSF.
39  */
40 static __inline u_int64_t
41 ath_extend_tsf15(u_int32_t rstamp, u_int64_t tsf)
42 {
43 	if ((tsf & 0x7fff) < rstamp)
44 		tsf -= 0x8000;
45 
46 	return ((tsf &~ 0x7fff) | rstamp);
47 }
48 
49 /*
50  * Extend 32-bit time stamp from rx descriptor to
51  * a full 64-bit TSF using the specified TSF.
52  */
53 static __inline u_int64_t
54 ath_extend_tsf32(u_int32_t rstamp, u_int64_t tsf)
55 {
56 	u_int32_t tsf_low = tsf & 0xffffffff;
57 	u_int64_t tsf64 = (tsf & ~0xffffffffULL) | rstamp;
58 
59 	if (rstamp > tsf_low && (rstamp - tsf_low > 0x10000000))
60 		tsf64 -= 0x100000000ULL;
61 
62 	if (rstamp < tsf_low && (tsf_low - rstamp > 0x10000000))
63 		tsf64 += 0x100000000ULL;
64 
65 	return tsf64;
66 }
67 
68 /*
69  * Extend the TSF from the RX descriptor to a full 64 bit TSF.
70  * Earlier hardware versions only wrote the low 15 bits of the
71  * TSF into the RX descriptor; later versions (AR5416 and up)
72  * include the 32 bit TSF value.
73  */
74 static __inline u_int64_t
75 ath_extend_tsf(struct ath_softc *sc, u_int32_t rstamp, u_int64_t tsf)
76 {
77 	if (sc->sc_rxtsf32)
78 		return ath_extend_tsf32(rstamp, tsf);
79 	else
80 		return ath_extend_tsf15(rstamp, tsf);
81 }
82 
83 #endif
84