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