xref: /freebsd/sys/dev/bwn/if_bwn_util.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * Copyright (c) 2009-2010 Weongyo Jeong <weongyo@freebsd.org>
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 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 /*
34  * The Broadcom Wireless LAN controller driver.
35  */
36 
37 #include "opt_bwn.h"
38 #include "opt_wlan.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/module.h>
45 #include <sys/endian.h>
46 #include <sys/errno.h>
47 #include <sys/firmware.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <machine/bus.h>
51 #include <machine/resource.h>
52 #include <sys/bus.h>
53 #include <sys/rman.h>
54 #include <sys/socket.h>
55 #include <sys/sockio.h>
56 
57 #include <net/ethernet.h>
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <net/if_arp.h>
61 #include <net/if_dl.h>
62 #include <net/if_llc.h>
63 #include <net/if_media.h>
64 #include <net/if_types.h>
65 
66 #include <dev/pci/pcivar.h>
67 #include <dev/pci/pcireg.h>
68 
69 #include <net80211/ieee80211_var.h>
70 #include <net80211/ieee80211_radiotap.h>
71 #include <net80211/ieee80211_regdomain.h>
72 #include <net80211/ieee80211_phy.h>
73 #include <net80211/ieee80211_ratectl.h>
74 
75 #include <dev/bwn/if_bwn_siba.h>
76 
77 #include <dev/bwn/if_bwnreg.h>
78 #include <dev/bwn/if_bwnvar.h>
79 
80 #include <dev/bwn/if_bwn_chipid.h>
81 #include <dev/bwn/if_bwn_debug.h>
82 #include <dev/bwn/if_bwn_misc.h>
83 #include <dev/bwn/if_bwn_util.h>
84 
85 unsigned int
86 bwn_sqrt(struct bwn_mac *mac, unsigned int x)
87 {
88 	/* Table holding (10 * sqrt(x)) for x between 1 and 256. */
89 	static uint8_t sqrt_table[256] = {
90 		10, 14, 17, 20, 22, 24, 26, 28,
91 		30, 31, 33, 34, 36, 37, 38, 40,
92 		41, 42, 43, 44, 45, 46, 47, 48,
93 		50, 50, 51, 52, 53, 54, 55, 56,
94 		57, 58, 59, 60, 60, 61, 62, 63,
95 		64, 64, 65, 66, 67, 67, 68, 69,
96 		70, 70, 71, 72, 72, 73, 74, 74,
97 		75, 76, 76, 77, 78, 78, 79, 80,
98 		80, 81, 81, 82, 83, 83, 84, 84,
99 		85, 86, 86, 87, 87, 88, 88, 89,
100 		90, 90, 91, 91, 92, 92, 93, 93,
101 		94, 94, 95, 95, 96, 96, 97, 97,
102 		98, 98, 99, 100, 100, 100, 101, 101,
103 		102, 102, 103, 103, 104, 104, 105, 105,
104 		106, 106, 107, 107, 108, 108, 109, 109,
105 		110, 110, 110, 111, 111, 112, 112, 113,
106 		113, 114, 114, 114, 115, 115, 116, 116,
107 		117, 117, 117, 118, 118, 119, 119, 120,
108 		120, 120, 121, 121, 122, 122, 122, 123,
109 		123, 124, 124, 124, 125, 125, 126, 126,
110 		126, 127, 127, 128, 128, 128, 129, 129,
111 		130, 130, 130, 131, 131, 131, 132, 132,
112 		133, 133, 133, 134, 134, 134, 135, 135,
113 		136, 136, 136, 137, 137, 137, 138, 138,
114 		138, 139, 139, 140, 140, 140, 141, 141,
115 		141, 142, 142, 142, 143, 143, 143, 144,
116 		144, 144, 145, 145, 145, 146, 146, 146,
117 		147, 147, 147, 148, 148, 148, 149, 149,
118 		150, 150, 150, 150, 151, 151, 151, 152,
119 		152, 152, 153, 153, 153, 154, 154, 154,
120 		155, 155, 155, 156, 156, 156, 157, 157,
121 		157, 158, 158, 158, 159, 159, 159, 160
122 	};
123 
124 	if (x == 0)
125 		return (0);
126 	if (x >= 256) {
127 		unsigned int tmp;
128 
129 		for (tmp = 0; x >= (2 * tmp) + 1; x -= (2 * tmp++) + 1)
130 			/* do nothing */ ;
131 		return (tmp);
132 	}
133 	return (sqrt_table[x - 1] / 10);
134 }
135