bcmwifi_channels.c

/*
 * Misc utility routines used by kernel or app-level.
 * Contents are wifi-specific, used by any kernel or app-level
 * software that might want wifi things as it grows.
 *
 * Copyright (C) 2024, Broadcom.
 *
 *      Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2 (the "GPL"),
 * available at http://www.broadcom.com/licenses/GPLv2.php, with the
 * following added to such license:
 *
 *      As a special exception, the copyright holders of this software give you
 * permission to link this software with independent modules, and to copy and
 * distribute the resulting executable under terms of your choice, provided that
 * you also meet, for each linked independent module, the terms and conditions of
 * the license of that module.  An independent module is a module which is not
 * derived from this software.  The special exception does not apply to any
 * modifications of the software.
 *
 *
 * <<Broadcom-WL-IPTag/Dual:>>
 */


#include <typedefs.h>
#include <bcmutils.h>
#include <bcmdefs.h>

#ifdef BCMDRIVER
#include <osl.h>
#define strtoul(nptr, endptr, base) bcm_strtoul((nptr), (endptr), (base))
#undef tolower
#define tolower(c) (bcm_isupper((c)) ? ((c) + 'a' - 'A') : (c))
#else
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#ifndef ASSERT
#define ASSERT(exp)
#endif
#ifndef ASSERT_FP
#define ASSERT_FP(exp)
#endif
#endif /* BCMDRIVER */

#include <bcmwifi_channels.h>

#if defined(WIN32) && (defined(BCMDLL) || defined(WLMDLL) || defined(_CONSOLE))
#include <bcmstdlib.h>	/* For wlexe/Makefile.wlm_dll */
#endif

#include <802.11.h>
#include <802.11ac.h>

/* Definitions for D11AC capable (80MHz+) Chanspec type */

/* Chanspec ASCII representation:
 *
 * [<band>'g']<channel>['/'<bandwidth>[<primary-sideband>]
 *    ['/'<1st-channel-segment>'-'<2nd-channel-segment>]]
 *
 * <band>:
 *      (optional) 2, 4, 5, 6 for 2.4GHz, 4GHz, 5GHz, and 6GHz respectively.
 *      Default value is 2g if channel <= 14, otherwise 5g.
 * <channel>:
 *      channel number of the 20MHz channel,
 *      or primary 20 MHz channel of 40MHz, 80MHz, 160MHz, 80+80MHz,
 *      or 320MHz channels.
 * <bandwidth>:
 *      (optional) 20, 40, 80, 160, 80+80, or 320. Default value is 20.
 * <primary-sideband>:
 *      'u' or 'l' (only for 2.4GHz band 40MHz)
 *
 *       For 2.4GHz band 40MHz channels, the same primary channel may be the
 *       upper sideband for one 40MHz channel, and the lower sideband for an
 *       overlapping 40MHz channel. The {u: upper, l: lower} primary sideband
 *       indication disambiguates which 40MHz channel is being specified.
 *
 *       For 40MHz in the 5GHz or 6GHz band and all channel bandwidths greater than
 *       40MHz, the U/L specification is not necessary or allowed since the channels are
 *       non-overlapping and the primary 20MHz channel position is derived from its
 *       position in the wide bandwidth channel.
 * <1st-channel-segment>
 * <2nd-channel-segment>:
 *       Required for 80+80, otherwise not allowed.
 *       These fields specify the center channel of the first and the second 80MHz
 *       or 160MHz channels.
 *
 * In its simplest form, it is a 20MHz channel number, with the implied band
 * of 2.4GHz if channel number <= 14, and 5GHz otherwise.
 *
 * To allow for backward compatibility with scripts, the old form for
 * 40MHz channels is also allowed: <channel><primary-sideband>
 *
 * <channel>:
 *	primary channel of 40MHz, channel <= 14 is 2GHz, otherwise 5GHz
 * <primary-sideband>:
 *	"U" for upper, "L" for lower (or lower case "u" "l")
 *
 * 5 GHz Examples:
 *      Chanspec        BW        Center Ch  Channel Range  Primary Ch
 *      5g8             20MHz     8          -              -
 *      52              20MHz     52         -              -
 *      52/40           40MHz     54         52-56          52
 *      56/40           40MHz     54         52-56          56
 *      52/80           80MHz     58         52-64          52
 *      56/80           80MHz     58         52-64          56
 *      60/80           80MHz     58         52-64          60
 *      64/80           80MHz     58         52-64          64
 *      52/160          160MHz    50         36-64          52
 *      36/160          160MGz    50         36-64          36
 *      36/80+80/42-106 80+80MHz  42,106     36-48,100-112  36
 *
 * 2 GHz Examples:
 *      Chanspec        BW        Center Ch  Channel Range  Primary Ch
 *      2g8             20MHz     8          -              -
 *      8               20MHz     8          -              -
 *      6               20MHz     6          -              -
 *      6/40l           40MHz     8          6-10           6
 *      6l              40MHz     8          6-10           6
 *      6/40u           40MHz     4          2-6            6
 *      6u              40MHz     4          2-6            6
 */

/* bandwidth ASCII string */
static const char *wf_chspec_bw_str[] =
{
	"320",
	"160+160",	/* NA */
	"20",
	"40",
	"80",
	"160",
	"80+80"
};

static const uint16 wf_chspec_bw_mhz[] = {
	320, 320, 20, 40, 80, 160, 160
};
#define WF_NUM_BW ARRAYSIZE(wf_chspec_bw_mhz)

/* 40MHz channels in 5GHz band */
static const uint8 wf_5g_40m_chans[] = {
	38, 46, 54, 62, 102, 110, 118, 126, 134, 142, 151, 159, 167, 175
};
#define WF_NUM_5G_40M_CHANS ARRAYSIZE(wf_5g_40m_chans)

/* 80MHz channels in 5GHz band */
static const uint8 wf_5g_80m_chans[] = {
	42, 58, 106, 122, 138, 155, 171
};
#define WF_NUM_5G_80M_CHANS ARRAYSIZE(wf_5g_80m_chans)

/* 160MHz channels in 5GHz band */
static const uint8 wf_5g_160m_chans[] = {
	50, 114, 163
};
#define WF_NUM_5G_160M_CHANS ARRAYSIZE(wf_5g_160m_chans)

/* 320Mhz Center chan to Chan Id map */
static const int8 map_320m_cc_chanid[] = {
	0,    /* CC 31 */
	1,    /* CC 95 */
	2,    /* CC 159 */
};

typedef struct {
	uint8 start;
	uint8 end;
	uint8 center;
	uint8 pad;
} wf_6g_320m_chan_range_t;

static const wf_6g_320m_chan_range_t wf_6g_320m_ch_set[] =
{
	{1, 61, 31, 0}, {65, 125, 95, 0}, {129, 189, 159, 0}
};

static const wf_6g_320m_chan_range_t wf_6g_320m_ch_ol_set[] =
{
	{33, 93, 63, 0}, {97, 157, 127, 0}, {161, 221, 191, 0}
};

static const uint ch_per_blk_map[] = {
	64,  /* WL_CHANSPEC_BW_320 */
	64,  /* WL_CHANSPEC_BW_320 */
	4,   /* WL_CHANSPEC_BW_20 */
	8,   /* WL_CHANSPEC_BW_40 */
	16,  /* WL_CHANSPEC_BW_80 */
	32,  /* WL_CHANSPEC_BW_160 */
	32,  /* WL_CHANSPEC_BW_160 */
};

/* Define the conditional macro to help with reducing the code size bloat
 * in other branches and in trunk targets that don't need 11BE features...
 */
#define WFC_2VALS_EQ(var, val)	((var) == (val))

/* compare bandwidth unconditionally for 320Mhz related stuff */
#if defined(WL11BE) || defined(BCMWIFI_BW320MHZ)
#define WFC_BW_EQ(bw, val)	WFC_2VALS_EQ(bw, val)
#else
#define WFC_BW_EQ(bw, val)	(FALSE)
#endif /* WL11BE || WL_BW320MHZ */

/* compare bandwidth based on WFC_NON_CONT_CHAN */
#ifdef WFC_NON_CONT_CHAN
#define WFC_NCBW_EQ(bw, val)	WFC_2VALS_EQ(bw, val)
#else
#define WFC_NCBW_EQ(bw, val)	(FALSE)
#endif

static void wf_chanspec_iter_firstchan(wf_chanspec_iter_t *iter);
static chanspec_bw_t wf_iter_next_bw(chanspec_bw_t bw);
static bool wf_chanspec_iter_next_2g(wf_chanspec_iter_t *iter);
static bool wf_chanspec_iter_next_5g(wf_chanspec_iter_t *iter);
static int wf_chanspec_iter_next_5g_range(wf_chanspec_iter_t *iter, chanspec_bw_t bw);
static bool wf_chanspec_iter_6g_range_init(wf_chanspec_iter_t *iter, chanspec_bw_t bw);
static bool wf_chanspec_iter_next_6g(wf_chanspec_iter_t *iter);
static uint wf_6g_get_center_chan_from_primary(uint primary_channel, chanspec_bw_t bw,
	bool overlapped320);

/**
 * Return the chanspec bandwidth in MHz
 * Bandwidth of 160 MHz will be returned for 80+80MHz chanspecs.
 *
 * @param	chspec		chanspec_t
 *
 * @return	bandwidth of chspec in MHz units
 */
uint
wf_bw_chspec_to_mhz(chanspec_t chspec)
{
	uint bwidx = WL_CHSPEC_BW(chspec);
	return (bwidx >= WF_NUM_BW ? 0 : wf_chspec_bw_mhz[bwidx]);
}

/* bw in MHz, return the channel count from the center channel to the
 * the channel at the edge of the band
 */
static uint
center_chan_to_edge(chanspec_bw_t bw)
{
	uint delta = 0;

	/* edge channels separated by BW - 10MHz on each side
	 * delta from cf to edge is half of that,
	 */
	if (bw == WL_CHANSPEC_BW_40) {
		/* 10 MHz */
		delta = 2;
	} else if (bw == WL_CHANSPEC_BW_80) {
		/* 30 MHz */
		delta = 6;
	} else if (bw == WL_CHANSPEC_BW_160) {
		/* 70 MHz */
		delta = 14;
	} else if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
		/* 150 MHz */
		delta = 30;
	}
	return delta;
}

/* return channel number of the low edge of the band
 * given the center channel and BW
 */
static uint
channel_low_edge(uint center_ch, chanspec_bw_t bw)
{
	return (center_ch - center_chan_to_edge(bw));
}

/* return side band number given center channel and primary20 channel
 * return -1 on error
 */
static int
channel_to_sb(uint center_ch, uint primary_ch, chanspec_bw_t bw)
{
	uint lowest = channel_low_edge(center_ch, bw);
	uint sb;

	if (primary_ch < lowest ||
	    (primary_ch - lowest) % 4) {
		/* bad primary channel lower than the low edge of the channel,
		 * or not mult 4.
		 */
		return -1;
	}

	sb = ((primary_ch - lowest) / 4);

	/* sb must be a index to a 20MHz channel in range */
	if ((bw == WL_CHANSPEC_BW_20 && sb >= 1) ||
	    (bw == WL_CHANSPEC_BW_40 && sb >= 2) ||
	    (bw == WL_CHANSPEC_BW_80 && sb >= 4) ||
	    (bw == WL_CHANSPEC_BW_160 && sb >= 8) ||
	    (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320) && sb >= 16)) {
		/* primary_ch must have been too high for the center_ch */
		return -1;
	}

	return sb;
}

/* return primary20 channel given center channel and side band */
static uint
channel_to_primary20_chan(uint center_ch, chanspec_bw_t bw, uint sb)
{
	return (channel_low_edge(center_ch, bw) + sb * 4);
}

/* return index of 80MHz channel from channel number
 * return -1 on error
 */
static int
channel_80mhz_to_id(uint ch)
{
	uint i;
	for (i = 0; i < WF_NUM_5G_80M_CHANS; i ++) {
		if (ch == wf_5g_80m_chans[i])
			return i;
	}

	return -1;
}

/* return index of the 6G 80MHz channel from channel number
 * return -1 on error
 */
static int
channel_6g_80mhz_to_id(uint ch)
{
	/* The 6GHz center channels start at 7, and have a spacing of 16 */
	if (ch >= CH_MIN_6G_80M_CHANNEL &&
	    ch <= CH_MAX_6G_80M_CHANNEL &&
	    ((ch - CH_MIN_6G_80M_CHANNEL) % 16) == 0) {  // even multiple of 16
		return (ch - CH_MIN_6G_80M_CHANNEL) / 16;
	}

	return -1;
}

/* return index of the 5G 160MHz channel from channel number
 * return -1 on error
 */
int
channel_5g_160mhz_to_id(uint ch)
{
	uint i;
	for (i = 0; i < WF_NUM_5G_160M_CHANS; i ++) {
		if (ch == wf_5g_160m_chans[i]) {
			return i;
		}
	}

	return -1;
}

/* return index of the 6G 160MHz channel from channel number
 * return -1 on error
 */
int
channel_6g_160mhz_to_id(uint ch)
{
	/* The 6GHz center channels start at 15, and have a spacing of 32 */
	if (ch >= CH_MIN_6G_160M_CHANNEL &&
	    ch <= CH_MAX_6G_160M_CHANNEL &&
	    ((ch - CH_MIN_6G_160M_CHANNEL) % 32) == 0) {
		return (ch - CH_MIN_6G_160M_CHANNEL) / 32;
	}

	return -1;
}


/* return index of the 6G 320MHz channel from channel number
 * return -1 on error
 */
int
channel_6g_320mhz_to_id(uint ch)
{
	int id;
	/* The 6GHz center channels start at 31, and have a spacing of 64 */
	if (ch >= CH_MIN_6G_320M_CHANNEL &&
	    ch <= CH_MAX_6G_320M_CHANNEL &&
	   ((((ch - CH_MIN_6G_320M_CHANNEL) %
		CH_6G_320M_CNTR_FREQ_SPACING) == 0) ||
		(ch >= CH_MIN_6G_320M_OL_CHANNEL &&
		((ch - CH_MIN_6G_320M_OL_CHANNEL) % CH_6G_320M_CNTR_FREQ_SPACING == 0)))) {

		uint8 pos = ch / CH_6G_320M_CNTR_FREQ_SPACING;
		if (pos < ARRAYSIZE(map_320m_cc_chanid)) {
			id = map_320m_cc_chanid[pos];
			if ((ch - CH_MIN_6G_320M_CHANNEL) % CH_6G_320M_CNTR_FREQ_SPACING == 0) {
				return id;
			} else {
				return (id + 4);
			}
		}
	}
	return -1;
}

/**
 * This function returns the the 5GHz 80MHz center channel for the given chanspec 80MHz ID
 *
 * @param    chan_80MHz_id    80MHz chanspec ID
 *
 * @return   Return the center channel number, or 0 on error.
 *
 */
static uint8
wf_chspec_5G_id80_to_ch(uint8 chan_80MHz_id)
{
	if (chan_80MHz_id < WF_NUM_5G_80M_CHANS) {
		return wf_5g_80m_chans[chan_80MHz_id];
	}

	return 0;
}

/**
 * This function returns the the 6GHz 80MHz center channel for the given chanspec 80MHz ID
 *
 * @param    chan_80MHz_id    80MHz chanspec ID
 *
 * @return   Return the center channel number, or 0 on error.
 *
 */
static uint8
wf_chspec_6G_id80_to_ch(uint8 chan_80MHz_id)
{
	uint8 ch = 0;

	if (chan_80MHz_id < WF_NUM_6G_80M_CHANS) {
		/* The 6GHz center channels have a spacing of 16
		 * starting from the first 80MHz center
		 */
		ch = CH_MIN_6G_80M_CHANNEL + (chan_80MHz_id * 16);
	}

	return ch;
}

/**
 * Convert chanspec to ascii string, or formats hex of an invalid chanspec.
 *
 * @param	chspec   chanspec to format
 * @param	buf      pointer to buf with room for at least CHANSPEC_STR_LEN bytes
 *
 * @return      Returns pointer to passed in buf. The buffer will have the ascii
 *              representation of the given chspec, or "invalid 0xHHHH" where
 *              0xHHHH is the hex representation of the invalid chanspec.
 *
 * @see		CHANSPEC_STR_LEN
 *
 * Wrapper function for wf_chspec_ntoa. In case of an error it puts
 * the original chanspec in the output buffer, prepended with "invalid".
 * Can be directly used in print routines as it takes care of null
 */
char *
wf_chspec_ntoa_ex(chanspec_t chspec, char *buf)
{
	if (wf_chspec_ntoa(chspec, buf) == NULL)
		snprintf(buf, CHANSPEC_STR_LEN, "invalid 0x%04x", chspec);
	return buf;
}

/**
 * Convert chanspec to ascii string, or return NULL on error.
 *
 * @param	chspec   chanspec to format
 * @param	buf      pointer to buf with room for at least CHANSPEC_STR_LEN bytes
 *
 * @return      Returns pointer to passed in buf or NULL on error. On sucess, the buffer
 *              will have the ascii representation of the given chspec.
 *
 * @see		CHANSPEC_STR_LEN
 *
 * Given a chanspec and a string buffer, format the chanspec as a
 * string, and return the original pointer buf.
 * Min buffer length must be CHANSPEC_STR_LEN.
 * On error return NULL.
 */
char *
wf_chspec_ntoa(chanspec_t chspec, char *buf)
{
	const char *band;
	uint pri_chan;

	if (wf_chspec_malformed(chspec))
		return NULL;

	band = "";

	/* primary20 channel */
	pri_chan = wf_chspec_primary20_chan(chspec);

	/* check for non-default band spec */
	if (CHSPEC_IS2G(chspec) && pri_chan > CH_MAX_2G_CHANNEL) {
		band = "2g";
	} else if (CHSPEC_IS5G(chspec) && pri_chan <= CH_MAX_2G_CHANNEL) {
		band = "5g";
	} else if (CHSPEC_IS6G(chspec)) {
		band = "6g";
	}

	/* bandwidth and primary20 sideband */
	if (CHSPEC_IS20(chspec)) {
		snprintf(buf, CHANSPEC_STR_LEN, "%s%d", band, pri_chan);
	} else if (CHSPEC_IS8080(chspec)) {
		/* 80+80 */
		uint ch0;
		uint ch1;

		/* get the center channels for each frequency segment */
		if (CHSPEC_IS5G(chspec)) {
			ch0 = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
			ch1 = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN1(chspec));
		} else if (CHSPEC_IS6G(chspec)) {
			ch0 = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
			ch1 = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN1(chspec));
		} else {
			return NULL;
		}

		/* Outputs a max of CHANSPEC_STR_LEN chars including '\0'  */
		snprintf(buf, CHANSPEC_STR_LEN, "%s%d/80+80/%d-%d", band, pri_chan, ch0, ch1);
	} else if (CHSPEC_IS320(chspec)) {
		/* 320 */
		const char *bw;
		const char *ol = "";

		bw = wf_chspec_to_bw_str(chspec);
		ol = WL_CHSPEC_320_CNTR_FREQ_OVERLAPPED(chspec) ? "o" : "";

		snprintf(buf, CHANSPEC_STR_LEN, "%s%d/%s%s", band, pri_chan, bw, ol);
	} else {
		const char *bw;
		const char *sb = "";

		bw = wf_chspec_to_bw_str(chspec);

#ifdef CHANSPEC_NEW_40MHZ_FORMAT
		/* primary20 sideband string if needed for 2g 40MHz */
		if (CHSPEC_IS40(chspec) && CHSPEC_IS2G(chspec)) {
			sb = CHSPEC_SB_UPPER(chspec) ? "u" : "l";
		}

		snprintf(buf, CHANSPEC_STR_LEN, "%s%d/%s%s", band, pri_chan, bw, sb);
#else
		/* primary20 sideband string instead of BW for 40MHz */
		if (CHSPEC_IS40(chspec) && !CHSPEC_IS6G(chspec)) {
			sb = CHSPEC_SB_UPPER(chspec) ? "u" : "l";
			snprintf(buf, CHANSPEC_STR_LEN, "%s%d%s", band, pri_chan, sb);
		} else {
			snprintf(buf, CHANSPEC_STR_LEN, "%s%d/%s", band, pri_chan, bw);
		}
#endif /* CHANSPEC_NEW_40MHZ_FORMAT */
	}

	return (buf);
}

static int
read_uint(const char **p, unsigned int *num)
{
	unsigned long val;
	char *endp = NULL;

	val = strtoul(*p, &endp, 10);
	/* if endp is the initial pointer value, then a number was not read */
	if (endp == *p)
		return 0;

	/* advance the buffer pointer to the end of the integer string */
	*p = endp;
	/* return the parsed integer */
	*num = (unsigned int)val;

	return 1;
}

/**
 * Convert ascii string to chanspec
 *
 * @param	a     pointer to input string
 *
 * @return	Return > 0 if successful or 0 otherwise
 */
chanspec_t
wf_chspec_aton(const char *a)
{
	chanspec_t chspec;
	chanspec_band_t chspec_band;
	chanspec_subband_t chspec_sb;
	chanspec_bw_t chspec_bw;
	uint bw;
	uint num, pri_ch;
	char c, sb_ul = '\0', overlap = '\0';

	bw = 20;
	chspec_sb = 0;

	/* parse channel num or band */
	if (!read_uint(&a, &num))
		return 0;
	/* if we are looking at a 'g', then the first number was a band */
	c = tolower((int)a[0]);
	if (c == 'g') {
		a++; /* consume the char */

		/* band must be "2", "5", or "6" */
		if (num == 2)
			chspec_band = WL_CHANSPEC_BAND_2G;
		else if (num == 5)
			chspec_band = WL_CHANSPEC_BAND_5G;
		else if (num == 6)
			chspec_band = WL_CHANSPEC_BAND_6G;
		else
			return 0;

		/* read the channel number */
		if (!read_uint(&a, &pri_ch))
			return 0;

		c = tolower((int)a[0]);
	} else {
		/* first number is channel, use default for band */
		pri_ch = num;
		chspec_band = ((pri_ch <= CH_MAX_2G_CHANNEL) ?
		               WL_CHANSPEC_BAND_2G : WL_CHANSPEC_BAND_5G);
	}

	if (c == '\0') {
		/* default BW of 20MHz */
		chspec_bw = WL_CHANSPEC_BW_20;
		goto done_read;
	}

	a ++; /* consume the 'u','l', or '/' */

	/* check 'u'/'l' */
	if (c == 'u' || c == 'l') {
		sb_ul = c;
		chspec_bw = WL_CHANSPEC_BW_40;
		goto done_read;
	}

	/* next letter must be '/' */
	if (c != '/')
		return 0;

	/* read bandwidth */
	if (!read_uint(&a, &bw))
		return 0;

	/* convert to chspec value */
	if (bw == 20) {
		chspec_bw = WL_CHANSPEC_BW_20;
	} else if (bw == 40) {
		chspec_bw = WL_CHANSPEC_BW_40;
	} else if (bw == 80) {
		chspec_bw = WL_CHANSPEC_BW_80;
	} else if (bw == 160) {
		chspec_bw = WL_CHANSPEC_BW_160;
	} else if (WFC_BW_EQ(bw, 320)) {
		chspec_bw = WL_CHANSPEC_BW_320;
	} else {
		return 0;
	}

	/* So far we have <band>g<chan>/<bw>
	 * Can now be followed by u/l if bw = 40,
	 */

	c = tolower((int)a[0]);

	/* if we have a 2g/40 channel, we should have a l/u spec now */
	if (chspec_band == WL_CHANSPEC_BAND_2G && bw == 40) {
		if (c == 'u' || c == 'l') {
			a ++; /* consume the u/l char */
			sb_ul = c;
			goto done_read;
		}
	}

	/* check for 80+80 */
	if (c == '+') {
		return 0;
	}

	/* if we have a 6g/320 channel, we should have a 'o' spec now for
	 * overlapped { 63, 127, 191 } channel.
	 */
	if (chspec_band == WL_CHANSPEC_BAND_6G && bw == 320) {
		if (c == 'o') {
			a ++; /* consume the 'o' char */
			overlap = c;
			goto done_read;
		}
	}
done_read:
	/* skip trailing white space */
	while (a[0] == ' ') {
		a ++;
	}

	/* must be end of string */
	if (a[0] != '\0')
		return 0;

	/* Now have all the chanspec string parts read;
	 * chspec_band, pri_ch, chspec_bw, sb_ul.
	 * chspec_band and chspec_bw are chanspec values.
	 * Need to convert pri_ch, and sb_ul into
	 * a center channel (or two) and sideband.
	 */

	/* if a sb u/l string was given, just use that,
	 * guaranteed to be bw = 40 by string parse.
	 */
	if (chspec_band != WL_CHANSPEC_BAND_6G && sb_ul != '\0') {
		if (sb_ul == 'l') {
			chspec_sb = WL_CHANSPEC_CTL_SB_LLL;
		} else if (sb_ul == 'u') {
			chspec_sb = WL_CHANSPEC_CTL_SB_LLU;
		}
		chspec = wf_create_40MHz_chspec_primary_sb(pri_ch, chspec_sb, chspec_band);
	} else if (chspec_bw == WL_CHANSPEC_BW_20) {
		/* if the bw is 20, only need the primary channel and band */
		chspec = wf_create_20MHz_chspec(pri_ch, chspec_band);
	} else {
		uint16 flags = 0;
		/* If the bw is 40/80/160 (and not 40MHz 2G), the channels are
		 * non-overlapping in 5G or 6G bands. Each primary channel is contained
		 * in only one higher bandwidth channel. The wf_create_chspec_from_primary()
		 * will create the chanspec. 2G 40MHz is handled just above, assuming a {u,l}
		 * sub-band spec was given.
		 * However 6g 320Mhz channels are overlapping and in case they are belongs to
		 * center channel set { 63, 127, 191 }, overlap should come with 'o'.
		 */
		if (WFC_BW_EQ(chspec_bw, WL_CHANSPEC_BW_320) && overlap == 'o') {
			flags |= WF_CHANSPEC_FLAG_OVERLAPPED320;
		}
		chspec = wf_create_chspec_from_primary(pri_ch, chspec_bw, chspec_band,
			flags);
	}

	if (wf_chspec_malformed(chspec))
		return 0;

	return chspec;
}

/**
 * Verify the chanspec is using a legal set of parameters, i.e. that the
 * chanspec specified a band, bw, pri_sb and channel and that the
 * combination could be legal given any set of circumstances.
 *
 * @param  chanspec   the chanspec to check
 *
 * @return Returns TRUE if the chanspec is malformed, FALSE if it looks good.
 */
bool
BCMPOSTTRAPFASTPATH(wf_chspec_malformed)(chanspec_t chanspec)
{
	uint chspec_bw = CHSPEC_BW(chanspec);
	uint chspec_sb;

	if (chanspec == INVCHANSPEC) {
		return TRUE;
	}
	if (CHSPEC_IS2G(chanspec)) {
		/* must be valid bandwidth for 2G */
		if (!BW_LE40(chspec_bw)) {
			return TRUE;
		}

		/* check for invalid channel number */
		if (wf_chspec_center_channel(chanspec) == INVCHANNEL) {
			return TRUE;
		}
	} else if (CHSPEC_IS5G(chanspec) || CHSPEC_IS6G(chanspec)) {
		if (WFC_BW_EQ(chspec_bw, WL_CHANSPEC_BW_320)) {
			uint ch_id;

			ch_id = WL_CHSPEC_320_CHAN(chanspec);

			/* channel IDs in 320 must be in range */
			if (CHSPEC_IS6G(chanspec)) {
				if (ch_id > WF_NUM_6G_320M_CHAN_ID_MAX) {
					/* bad 320MHz channel ID for the band */
					return TRUE;
				}
			} else {
				return TRUE;
			}
		} else if (WFC_NCBW_EQ(chspec_bw, WL_CHANSPEC_BW_8080)) {
			uint ch0_id, ch1_id;

			ch0_id = WL_CHSPEC_CHAN0(chanspec);
			ch1_id = WL_CHSPEC_CHAN1(chanspec);

			/* channel IDs in 80+80 must be in range */
			if (CHSPEC_IS5G(chanspec) &&
			    (ch0_id >= WF_NUM_5G_80M_CHANS || ch1_id >= WF_NUM_5G_80M_CHANS)) {
				/* bad 80MHz channel ID for the band */
				return TRUE;
			}
			if (CHSPEC_IS6G(chanspec) &&
			    (ch0_id >= WF_NUM_6G_80M_CHANS || ch1_id >= WF_NUM_6G_80M_CHANS)) {
				/* bad 80MHz channel ID for the band */
				return TRUE;
			}
		} else if (chspec_bw == WL_CHANSPEC_BW_20 || chspec_bw == WL_CHANSPEC_BW_40 ||
		           chspec_bw == WL_CHANSPEC_BW_80 || chspec_bw == WL_CHANSPEC_BW_160) {

			/* check for invalid channel number */
			if (wf_chspec_center_channel(chanspec) == INVCHANNEL) {
				return TRUE;
			}
		} else {
			/* invalid bandwidth */
			return TRUE;
		}
	} else {
		/* must be a valid band */
		return TRUE;
	}

	/* retrive sideband */
	if (WFC_BW_EQ(chspec_bw, WL_CHANSPEC_BW_320)) {
		chspec_sb = CHSPEC_320_SB(chanspec);
	} else {
		chspec_sb = CHSPEC_CTL_SB(chanspec);
	}

	/* side band needs to be consistent with bandwidth */
	if (chspec_bw == WL_CHANSPEC_BW_20) {
		if (chspec_sb != WL_CHANSPEC_CTL_SB_LLL)
			return TRUE;
	} else if (chspec_bw == WL_CHANSPEC_BW_40) {
		if (chspec_sb > WL_CHANSPEC_CTL_SB_LLU)
			return TRUE;
	} else if (chspec_bw == WL_CHANSPEC_BW_80 ||
	           WFC_NCBW_EQ(chspec_bw, WL_CHANSPEC_BW_8080)) {
		/* both 80MHz and 80+80MHz use 80MHz side bands.
		 * 80+80 SB info is relative to the primary 80MHz sub-band.
		 */
		if (chspec_sb > WL_CHANSPEC_CTL_SB_LUU)
			return TRUE;
	} else if (WFC_BW_EQ(chspec_bw, WL_CHANSPEC_BW_320)) {
		/* FIXME: define the max sideband index */
		ASSERT_FP((chspec_sb >> WL_CHANSPEC_320_SB_SHIFT) <= 15);
	}

	return FALSE;
}

/**
 * Verify the chanspec specifies a valid channel according to 802.11.
 *
 * @param   chanspec     the chanspec to check
 *
 * @return  Returns TRUE if the chanspec is a valid 802.11 channel
 */
bool
wf_chspec_valid(chanspec_t chanspec)
{
	chanspec_band_t chspec_band = CHSPEC_BAND(chanspec);
	chanspec_bw_t chspec_bw = CHSPEC_BW(chanspec);
	uint chspec_ch = -1;

	if (wf_chspec_malformed(chanspec)) {
		return FALSE;
	}

	chspec_ch = wf_chspec_center_channel(chanspec);

	/* After the malformed check, we know that we have
	 * a valid band field,
	 * a valid bandwidth for the band,
	 * and a valid sub-band value for the bandwidth.
	 *
	 * Since all sub-band specs are valid for any channel, the only thing remaining to
	 * check is that
	 *   the 20MHz channel,
	 *   or the center channel for higher BW,
	 *   or both center channels for an 80+80MHz channel,
	 * are valid for the specified band.
	 * Also, 80+80MHz channels need to be non-contiguous.
	 */

	if (chspec_bw == WL_CHANSPEC_BW_20) {

		return wf_valid_20MHz_chan(chspec_ch, chspec_band);

	} else if (chspec_bw == WL_CHANSPEC_BW_40) {

		return wf_valid_40MHz_center_chan(chspec_ch, chspec_band);

	} else if (chspec_bw == WL_CHANSPEC_BW_80) {

		return wf_valid_80MHz_center_chan(chspec_ch, chspec_band);

	} else if (chspec_bw == WL_CHANSPEC_BW_160) {

		return wf_valid_160MHz_center_chan(chspec_ch, chspec_band);

	} else if (WFC_BW_EQ(chspec_bw, WL_CHANSPEC_BW_320)) {
		return wf_valid_320MHz_center_chan(chspec_ch, chspec_band);

	} else if (WFC_NCBW_EQ(chspec_bw, WL_CHANSPEC_BW_8080)) {
		uint16 ch0 = 0;
		uint16 ch1 = 0;

		/* get the center channels for each frequency segment */
		if (CHSPEC_IS5G(chanspec)) {
			ch0 = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN0(chanspec));
			ch1 = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN1(chanspec));
		} else if (CHSPEC_IS6G(chanspec)) {
			ch0 = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN0(chanspec));
			ch1 = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN1(chanspec));
		} else {
			return FALSE;
		}

		/* the two channels must be separated by more than 80MHz by VHT req */
		if ((ch1 > ch0 + CH_80MHZ_APART) ||
		    (ch0 > ch1 + CH_80MHZ_APART))
			return TRUE;
	}

	return FALSE;
}

/**
 * Verify the chanspec is greater than or equal to the given bandwidth.
 *
 * @param   chanspec     the chanspec to check
 * @param   chspec_bw    the bandwidth to check
 *
 * @return  Returns TRUE if the chanspec is greater than or equal to
 *          the bandwidth
 */
bool
wf_chspec_bw_ge(chanspec_t chanspec, chanspec_bw_t chspec_bw)
{
	bool chspec_bw_ge = FALSE;

	/* BW inequality comparisons, GE (>=), comparisons can be made as simple numeric
	 * comparisons, with the exception that 160 is the same bandwidth as 80+80,
	 * but have different numeric values (WL_CHANSPEC_BW_160 < WL_CHANSPEC_BW_8080).
	 * For 320 wide bandwidth, the numeric values (WL_CHANSPEC_BW_320) is lesser than
	 * the other bandwidths 20, 40, 80, 80+80 and 160.
	 *
	 * Check first whether both chanspec bandwidth and chspec_bw are 160 wide. If chanspec
	 * bandwidth is 320 wide, then the opposite inequality is made as 320 bandwidth numeric
	 * value is lesser than other bandwidth values. Otherwise, the regular comparison is made.
	 */
	if (CHSPEC_IS_BW_160_WIDE(chanspec) && BW_IS_160_WIDE(chspec_bw)) {
		chspec_bw_ge = TRUE;
	} else if (CHSPEC_BW(chanspec) == WL_CHANSPEC_BW_320) {
		chspec_bw_ge = TRUE;
	} else if (chspec_bw != WL_CHANSPEC_BW_320) {
		chspec_bw_ge = (CHSPEC_BW(chanspec) >= chspec_bw);
	}

	return chspec_bw_ge;
}

/**
 * Verify the chanspec is lesser than or equal to the given bandwidth.
 *
 * @param   chanspec     the chanspec to check
 * @param   chspec_bw    the bandwidth to check
 *
 * @return  Returns TRUE if the chanspec is lesser than or equal to
 *          the bandwidth
 */
bool
wf_chspec_bw_le(chanspec_t chanspec, chanspec_bw_t chspec_bw)
{
	bool chspec_bw_le = FALSE;

	/* BW inequality comparisons, LE (<=), comparisons can be made as simple numeric
	 * comparisons, with the exception that 160 is the same bandwidth as 80+80,
	 * but have different numeric values (WL_CHANSPEC_BW_160 < WL_CHANSPEC_BW_8080).
	 * For 320 wide bandwidth, the numeric values (WL_CHANSPEC_BW_320) is lesser than
	 * the other bandwidths 20, 40, 80, 80+80 and 160.
	 *
	 * Check first whether both chanspec bandwidth and chspec_bw are 160 wide. If chanspec
	 * bandwidth is 320 wide, then the opposite inequality is made as 320 bandwidth numeric
	 * value is lesser than other bandwidth values. Otherwise, the regular comparison is made.
	 */
	if (CHSPEC_IS_BW_160_WIDE(chanspec) && BW_IS_160_WIDE(chspec_bw)) {
		chspec_bw_le = TRUE;
	} else if (chspec_bw == WL_CHANSPEC_BW_320) {
		chspec_bw_le = TRUE;
	} else if (CHSPEC_BW(chanspec) != WL_CHANSPEC_BW_320) {
		chspec_bw_le = (CHSPEC_BW(chanspec) <= chspec_bw);
	}

	return chspec_bw_le;
}

/* 5G band 20MHz channel ranges with even (+4) channel spacing */
static const struct wf_iter_range wf_5g_iter_ranges[] = {
	{36, 64},
	{100, 144},
	{149, 165}
};

#define RANGE_ID_INVAL 0xFFu
enum wf_iter_state {
	WF_ITER_INIT = 0,
	WF_ITER_RUN  = 1,
	WF_ITER_DONE = 2
};

/**
 * @brief  Initialize a chanspec iteration structure.
 */
bool
wf_chanspec_iter_init(wf_chanspec_iter_t *iter, chanspec_band_t band, chanspec_bw_t bw)
{
	if (iter == NULL) {
		return FALSE;
	}

	/* Initialize the iter structure to the "DONE" state
	 * in case the parameter validation fails.
	 * If the validation fails then the iterator will return INVCHANSPEC as the current
	 * chanspec, and wf_chanspec_iter_next() will return FALSE.
	 */
	bzero(iter, sizeof(*iter));
	iter->state = WF_ITER_DONE;
	iter->chanspec = INVCHANSPEC;

	if (band != WL_CHANSPEC_BAND_2G &&
	    band != WL_CHANSPEC_BAND_5G &&
	    band != WL_CHANSPEC_BAND_6G) {
		ASSERT(0);
		return FALSE;
	}

	/* make sure the BW is unspecified (INVCHANSPEC), 20/40,
	 * or (not 2g and 80/160)
	 */
	if (!(bw == INVCHANSPEC ||
	      bw == WL_CHANSPEC_BW_20 ||
	      bw == WL_CHANSPEC_BW_40 ||
	      (band != WL_CHANSPEC_BAND_2G &&
	       (bw == WL_CHANSPEC_BW_80 ||
	        bw == WL_CHANSPEC_BW_160 ||
	        WFC_BW_EQ(bw, WL_CHANSPEC_BW_320))))) {

		ASSERT(0);
		return FALSE;
	}

	/* Validation of the params is successful so move to the "INIT" state to
	 * allow the first wf_chanspec_iter_next() move the iteration to the first
	 * chanspec in the set.
	 */
	iter->state = WF_ITER_INIT;
	iter->band = band;
	iter->bw = bw;
	iter->range_id = RANGE_ID_INVAL;

	return TRUE;
}

/**
 * Start the iterator off from the 'init' state.
 * The internal state is set up and advanced to the first chanspec.
 */
static void
wf_chanspec_iter_firstchan(wf_chanspec_iter_t *iter)
{
	chanspec_band_t band = iter->band;
	chanspec_bw_t bw = iter->bw;
	chanspec_t chspec;

	/* if BW unspecified (INVCHANSPEC), start with 20 MHz */
	if (bw == INVCHANSPEC) {
		bw = WL_CHANSPEC_BW_20;
	}

	/* calc the initial channel based on band */
	if (band == WL_CHANSPEC_BAND_2G) {
		/* 2g has overlapping 40MHz channels, so cannot just use the
		 * wf_create_chspec_from_primary() fn.
		 */
		if (bw == WL_CHANSPEC_BW_20) {
			chspec = wf_create_20MHz_chspec(CH_MIN_2G_CHANNEL, band);
		} else {
			chspec = (WL_CHANSPEC_BAND_2G | bw | WL_CHANSPEC_CTL_SB_L |
			          CH_MIN_2G_40M_CHANNEL);
		}
	} else {
		if (band == WL_CHANSPEC_BAND_5G) {
			wf_chanspec_iter_next_5g_range(iter, bw);
			chspec = wf_create_chspec_from_primary(iter->range.start, bw, band, 0);
		} else {
			wf_chanspec_iter_6g_range_init(iter, bw);
			/* First 6g 320Mhz chanspec */
			chspec = wf_create_chspec_from_primary(iter->range.start, bw, band, 0);
		}
	}

	iter->chanspec = chspec;
}

/**
 * @brief Return the current chanspec of the iteration.
 */
chanspec_t
wf_chanspec_iter_current(wf_chanspec_iter_t *iter)
{
	return iter->chanspec;
}

/**
 * @brief Advance the iteration to the next chanspec in the set.
 */
bool
wf_chanspec_iter_next(wf_chanspec_iter_t *iter, chanspec_t *chspec)
{
	bool ok = FALSE;
	chanspec_band_t band = iter->band;

	/* Handle the INIT and DONE states. Otherwise, we are in the RUN state
	 * and will dispatch to the 'next' function for the appropriate band.
	 */
	if (iter->state == WF_ITER_INIT) {
		iter->state = WF_ITER_RUN;
		wf_chanspec_iter_firstchan(iter);
		ok = TRUE;
	} else if (iter->state == WF_ITER_DONE) {
		ok = FALSE;
	} else if (band == WL_CHANSPEC_BAND_2G) {
		ok = wf_chanspec_iter_next_2g(iter);
	} else if (band == WL_CHANSPEC_BAND_5G) {
		ok = wf_chanspec_iter_next_5g(iter);
	} else if (band == WL_CHANSPEC_BAND_6G) {
		ok = wf_chanspec_iter_next_6g(iter);
	}

	/* Return the new chanspec if a pointer was provided.
	 * In case the iteration is done, the return will be INVCHANSPEC.
	 */
	if (chspec != NULL) {
		*chspec = iter->chanspec;
	}

	return ok;
}

/**
 * When the iterator completes a particular bandwidth, this function
 * returns the next BW, or INVCHANSPEC when done.
 *
 * Internal iterator helper.
 */
static chanspec_bw_t
wf_iter_next_bw(chanspec_bw_t bw)
{
	switch (bw) {
	case WL_CHANSPEC_BW_20:
		bw = WL_CHANSPEC_BW_40;
		break;
	case WL_CHANSPEC_BW_40:
		bw = WL_CHANSPEC_BW_80;
		break;
	case WL_CHANSPEC_BW_80:
		bw = WL_CHANSPEC_BW_160;
		break;
#if defined(BCMWIFI_BW320MHZ)
	case WL_CHANSPEC_BW_160:
		bw = WL_CHANSPEC_BW_320;
		break;
#endif /* WL_BW320MHZ */
	default:
		bw = INVCHANSPEC;
		break;
	}
	return bw;
}

/**
 * This is the _iter_next() helper for 2g band chanspec iteration.
 */
static bool
wf_chanspec_iter_next_2g(wf_chanspec_iter_t *iter)
{
	chanspec_t chspec = iter->chanspec;
	uint8 ch = wf_chspec_center_channel(chspec);

	if (CHSPEC_IS20(chspec)) {
		if (ch < CH_MAX_2G_CHANNEL) {
			ch++;
			chspec = wf_create_20MHz_chspec(ch, WL_CHANSPEC_BAND_2G);
		} else if (iter->bw == INVCHANSPEC) {
			/* hit the end of 20M channels, go to 40M if bw was unspecified */
			ch = CH_MIN_2G_40M_CHANNEL;
			chspec = wf_create_40MHz_chspec(LOWER_20_SB(ch), ch, WL_CHANSPEC_BAND_2G);
		} else {
			/* done */
			iter->state = WF_ITER_DONE;
			chspec = INVCHANSPEC;
		}
	} else {
		/* step through low then high primary sideband, then next 40 center channel */
		if (CHSPEC_SB_LOWER(iter->chanspec)) {
			/* move from lower primary 20 to upper */
			chspec = wf_create_40MHz_chspec(UPPER_20_SB(ch),
			                                ch, WL_CHANSPEC_BAND_2G);
		} else if (ch < CH_MAX_2G_40M_CHANNEL) {
			/* move to next 40M center and lower primary 20 */
			ch++;
			chspec = wf_create_40MHz_chspec(LOWER_20_SB(ch),
			                                ch, WL_CHANSPEC_BAND_2G);
		} else {
			/* done */
			iter->state = WF_ITER_DONE;
			chspec = INVCHANSPEC;
		}
	}

	iter->chanspec = chspec;

	return (chspec != INVCHANSPEC);
}

/**
 * This is the _iter_next() helper for 5g band chanspec iteration.
 * The 5g iterator uses ranges of primary 20MHz channels, and the current BW, to create
 * each chanspec in the set.
 * When a 5g range is exhausted, wf_chanspec_iter_next_5g_range() is called to get the next
 * range appropriate to the current BW.
 */
static bool
wf_chanspec_iter_next_5g(wf_chanspec_iter_t *iter)
{
	chanspec_t chspec = iter->chanspec;
	chanspec_bw_t bw = CHSPEC_BW(chspec);
	uint8 ch = wf_chspec_primary20_chan(chspec);
	uint8 end = iter->range.end;

	if (ch < end) {
		/* not at the end of the current range, so
		 * step to the next 20MHz channel and create the current BW
		 * channel with that new primary 20MHz.
		 */
		ch += CH_20MHZ_APART;
	} else if (wf_chanspec_iter_next_5g_range(iter, bw)) {
		/* there was a new range in the current BW, so start at the beginning */
		ch = iter->range.start;
	} else if (iter->bw == INVCHANSPEC) {
		/* hit the end of current bw, so move to the next bw */
		bw = wf_iter_next_bw(bw);
		if (bw != INVCHANSPEC) {
			/* initialize the first range */
			iter->range_id = RANGE_ID_INVAL;
			wf_chanspec_iter_next_5g_range(iter, bw);
			ch = iter->range.start;
		} else {
			/* no more BWs */
			chspec = INVCHANSPEC;
		}
	} else {
		/* no more channels, ranges, or BWs */
		chspec = INVCHANSPEC;
	}

	/* if we are not at the end of the iteration, calc the next chanspec from components */
	if (chspec != INVCHANSPEC) {
		chspec = wf_create_chspec_from_primary(ch, bw, WL_CHANSPEC_BAND_5G, 0);
	}

	iter->chanspec = chspec;
	if (chspec != INVCHANSPEC) {
		return TRUE;
	} else {
		iter->state = WF_ITER_DONE;
		return FALSE;
	}
}

/**
 * Helper function to set up the next range of primary 20MHz channels to
 * iterate over for the current BW. This will advance
 *    iter->range_id
 * and set up
 *    iter->range.start
 *    iter->range.end
 * for the new range.
 * Returns FALSE if there are no more ranges in the current BW.
 */
static int
wf_chanspec_iter_next_5g_range(wf_chanspec_iter_t *iter, chanspec_bw_t bw)
{
	uint8 range_id = iter->range_id;
	const uint8 *channels;
	uint count;

	if (bw == WL_CHANSPEC_BW_20) {
		if (range_id == RANGE_ID_INVAL) {
			range_id = 0;
		} else {
			range_id++;
		}

		if (range_id < ARRAYSIZE(wf_5g_iter_ranges)) {
			iter->range_id = range_id;
			iter->range = wf_5g_iter_ranges[range_id];
			return TRUE;
		}

		return FALSE;
	}

	if (bw == WL_CHANSPEC_BW_40) {
		channels = wf_5g_40m_chans;
		count = WF_NUM_5G_40M_CHANS;
	} else if (bw == WL_CHANSPEC_BW_80) {
		channels = wf_5g_80m_chans;
		count = WF_NUM_5G_80M_CHANS;
	} else if (bw == WL_CHANSPEC_BW_160) {
		channels = wf_5g_160m_chans;
		count = WF_NUM_5G_160M_CHANS;
	} else {
		return FALSE;
	}

	if (range_id == RANGE_ID_INVAL) {
		range_id = 0;
	} else {
		range_id++;
	}
	if (range_id < count) {
		uint8 ch = channels[range_id];
		uint offset = center_chan_to_edge(bw);

		iter->range_id = range_id;
		iter->range.start = ch - offset;
		iter->range.end = ch + offset;
		return TRUE;
	}

	return FALSE;
}

/**
 * This is the _iter_next() helper for 6g band chanspec iteration.
 * The 6g iterator uses ranges of primary 20MHz channels, and the current BW, to create
 * each chanspec in the set.
 * Each BW in 6g has one contiguous range of primary 20MHz channels. When a range is
 * exhausted, the iterator moves to the next BW.
 */
static bool
wf_chanspec_iter_next_6g(wf_chanspec_iter_t *iter)
{
	chanspec_t chspec = iter->chanspec;
	chanspec_bw_t bw = CHSPEC_BW(chspec);
	uint8 ch = wf_chspec_primary20_chan(chspec);
	uint8 end = iter->range.end;
	uint16 flags = 0;
	BCM_REFERENCE(flags);
	if ((ch < end) && (ch != 2)) {
		/* not at the end of the current range, so
		 * step to the next 20MHz channel and create the current BW
		 * channel with that new primary 20MHz.
		 */
		ch += CH_20MHZ_APART;

		if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
			if (iter->range_id % 2) {
				flags |= WF_CHANSPEC_FLAG_OVERLAPPED320;
			}
		}
		/* try to create a valid channel of the current BW
		 * with a primary20 'ch'
		 */
		chspec = wf_create_chspec_from_primary(ch, bw, WL_CHANSPEC_BAND_6G,
			flags);

		/* if chspec is INVCHANSPEC, then we hit the end
		 * of the valid channels in the range.
		 */
	}
	else if ((ch != 2) && (bw == WL_CHANSPEC_BW_20)) {
		/* channel 2 need special handling as it doesnot follow
		 * 20mhz channel numbering rule with (chan-1)%4=0
		 * It is placed at the end of 20Mhz channel list
		 */
		chspec = wf_create_chspec_from_primary(2, bw, WL_CHANSPEC_BAND_6G, 0);
	} else if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320) && wf_chanspec_iter_6g_range_init(iter, bw)) {
		/* there was a new range in the current BW, so start at the beginning */
		ch = iter->range.start;
		if (iter->range_id % 2) {
			flags |= WF_CHANSPEC_FLAG_OVERLAPPED320;
		}
		/* try to create a valid channel of the current BW
		 * with a primary20 'ch'
		 */
		chspec = wf_create_chspec_from_primary(ch, bw, WL_CHANSPEC_BAND_6G, flags);
	} else {
		/* hit the end of the current range */
		chspec = INVCHANSPEC;
	}

	/* if we are at the end of the current channel range
	 * check if there is another BW to iterate
	 * Note: (iter->bw == INVCHANSPEC) indicates an unspecified BW for the interation,
	 * so it will iterate over all BWs.
	 */
	if (chspec == INVCHANSPEC &&
	    iter->bw == INVCHANSPEC &&
	    (bw = wf_iter_next_bw(bw)) != INVCHANSPEC) {
		wf_chanspec_iter_6g_range_init(iter, bw);
		/* start the new bw with the first primary20 */
		ch = iter->range.start;
		if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320) && iter->range_id != RANGE_ID_INVAL &&
			iter->range_id % 2) {
			flags |= WF_CHANSPEC_FLAG_OVERLAPPED320;
		}
		chspec = wf_create_chspec_from_primary(ch, bw, WL_CHANSPEC_BAND_6G, flags);
	}

	iter->chanspec = chspec;
	if (chspec != INVCHANSPEC) {
		return TRUE;
	} else {
		iter->state = WF_ITER_DONE;
		return FALSE;
	}
}

/**
 * Helper used by wf_chanspec_iter_firstchan() to set up the first range of
 * primary channels for the 6g band and for the BW being iterated.
 */
static bool
wf_chanspec_iter_6g_range_init(wf_chanspec_iter_t *iter, chanspec_bw_t bw)
{
	bool ret = FALSE;
	if (bw == WL_CHANSPEC_BW_20 || bw == WL_CHANSPEC_BW_40 ||
		bw == WL_CHANSPEC_BW_80 || bw == WL_CHANSPEC_BW_160) {
		iter->range.start = CH_MIN_6G_CHANNEL;
		iter->range.end   = CH_MAX_6G_CHANNEL;
	} else if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
		if (iter->range_id == RANGE_ID_INVAL) {
			iter->range_id = 0;
		} else {
			iter->range_id++;
		}
		if (iter->range_id == 0) {
			iter->range.start = CH_MIN_6G_320M_START_CHAN;
			iter->range.end   = (iter->range.start +
				CH_6G_320M_CNTR_FREQ_SPACING) - CH_20MHZ_APART;
			iter->range.end = MIN(iter->range.end, CH_MAX_6G_320M_END_CHAN);
			ret = TRUE;
		} else if (iter->range_id < WF_NUM_6G_320M_CHANS) {
			iter->range.start = iter->range.start + (CH_6G_320M_CNTR_FREQ_SPACING / 2u);
			iter->range.end   = (iter->range.start +
				CH_6G_320M_CNTR_FREQ_SPACING) - CH_20MHZ_APART;
			iter->range.end = MIN(iter->range.end, CH_MAX_6G_320M_END_CHAN);
			ret = TRUE;
		} else {
			ret = FALSE;
		}
	} else {
		ASSERT(0);
	}
	return ret;
}

/**
 * Verify that the channel is a valid 20MHz channel according to 802.11.
 *
 * @param  channel   20MHz channel number to validate
 * @param  band      chanspec band
 *
 * @return Return TRUE if valid
 */
bool
wf_valid_20MHz_chan(uint channel, chanspec_band_t band)
{
	if (band == WL_CHANSPEC_BAND_2G) {
		/* simple range check for 2GHz */
		return (channel >= CH_MIN_2G_CHANNEL &&
		        channel <= CH_MAX_2G_CHANNEL);
	} else if (band == WL_CHANSPEC_BAND_5G) {
		const uint8 *center_ch = wf_5g_40m_chans;
		uint num_ch = WF_NUM_5G_40M_CHANS;
		uint i;

		/* We don't have an array of legal 20MHz 5G channels, but they are
		 * each side of the legal 40MHz channels.  Check the chanspec
		 * channel against either side of the 40MHz channels.
		 */
		for (i = 0; i < num_ch; i ++) {
			if (channel == (uint)LOWER_20_SB(center_ch[i]) ||
			    channel == (uint)UPPER_20_SB(center_ch[i])) {
				break; /* match found */
			}
		}

		if (i == num_ch) {
			/* check for legacy JP channels on failure */
			if (channel == 34 || channel == 38 ||
			    channel == 42 || channel == 46) {
				i = 0;
			}
		}

		if (i < num_ch) {
			/* match found */
			return TRUE;
		}
	}
	else if (band == WL_CHANSPEC_BAND_6G) {
		/* Use the simple pattern of 6GHz 20MHz channels for validity check */
		if ((channel >= CH_MIN_6G_CHANNEL &&
		     channel <= CH_MAX_6G_CHANNEL) &&
		    ((((channel - CH_MIN_6G_CHANNEL) % 4) == 0) || // even multiple of 4
		     channel == 2)) { // Or the oddball channel 2
			return TRUE;
		}
	}

	return FALSE;
}

/**
 * Verify that the center channel is a valid 40MHz center channel according to 802.11.
 *
 * @param  center_channel   40MHz center channel to validate
 * @param  band             chanspec band
 *
 * @return Return TRUE if valid
 */
bool
wf_valid_40MHz_center_chan(uint center_channel, chanspec_band_t band)
{
	if (band == WL_CHANSPEC_BAND_2G) {
		/* simple range check for 2GHz */
		return (center_channel >= CH_MIN_2G_40M_CHANNEL &&
		        center_channel <= CH_MAX_2G_40M_CHANNEL);
	} else if (band == WL_CHANSPEC_BAND_5G) {
		uint i;

		/* use the 5GHz lookup of 40MHz channels */
		for (i = 0; i < WF_NUM_5G_40M_CHANS; i++) {
			if (center_channel == wf_5g_40m_chans[i]) {
				return TRUE;
			}
		}
	}
	else if (band == WL_CHANSPEC_BAND_6G) {
		/* Use the simple pattern of 6GHz center channels */
		if ((center_channel >= CH_MIN_6G_40M_CHANNEL &&
		     center_channel <= CH_MAX_6G_40M_CHANNEL) &&
		    ((center_channel - CH_MIN_6G_40M_CHANNEL) % 8) == 0) {  // even multiple of 8
			return TRUE;
		}
	}

	return FALSE;
}

/**
 * Verify that the center channel is a valid 80MHz center channel according to 802.11.
 *
 * @param  center_channel   80MHz center channel to validate
 * @param  band             chanspec band
 *
 * @return Return TRUE if valid
 */
bool
wf_valid_80MHz_center_chan(uint center_channel, chanspec_band_t band)
{
	if (band == WL_CHANSPEC_BAND_5G) {
		/* use the 80MHz ID lookup to validate the center channel */
		if (channel_80mhz_to_id(center_channel) >= 0) {
			return TRUE;
		}
	} else if (band == WL_CHANSPEC_BAND_6G) {
		/* use the 80MHz ID lookup to validate the center channel */
		if (channel_6g_80mhz_to_id(center_channel) >= 0) {
			return TRUE;
		}
	}

	return FALSE;
}

/**
 * Verify that the center channel is a valid 160MHz center channel according to 802.11.
 *
 * @param  center_channel   160MHz center channel to validate
 * @param  band             chanspec band
 *
 * @return Return TRUE if valid
 */
bool
wf_valid_160MHz_center_chan(uint center_channel, chanspec_band_t band)
{
	if (band == WL_CHANSPEC_BAND_5G) {
		uint i;

		/* use the 5GHz lookup of 40MHz channels */
		for (i = 0; i < WF_NUM_5G_160M_CHANS; i++) {
			if (center_channel == wf_5g_160m_chans[i]) {
				return TRUE;
			}
		}
	} else if (band == WL_CHANSPEC_BAND_6G) {
		/* Use the simple pattern of 6GHz center channels */
		if ((center_channel >= CH_MIN_6G_160M_CHANNEL &&
		     center_channel <= CH_MAX_6G_160M_CHANNEL) &&
		    ((center_channel - CH_MIN_6G_160M_CHANNEL) % 32) == 0) { // even multiple of 32
			return TRUE;
		}
	}

	return FALSE;
}


/**
 * Verify that the center channel is a valid 320MHz center channel according to 802.11.
 *
 * @param  center_channel   320MHz center channel to validate
 * @param  band             chanspec band
 *
 * @return Return TRUE if valid
 */
bool
wf_valid_320MHz_center_chan(uint center_channel, chanspec_band_t band)
{
	if (band == WL_CHANSPEC_BAND_6G) {
		/* Use the simple pattern of 6GHz center channels */
		if ((center_channel >= CH_MIN_6G_320M_CHANNEL &&
		     center_channel <= CH_MAX_6G_320M_CHANNEL) &&
		    (((center_channel - CH_MIN_6G_320M_CHANNEL) %
			 CH_6G_320M_CNTR_FREQ_SPACING == 0) ||
			 (((center_channel - CH_MIN_6G_320M_OL_CHANNEL) %
			 CH_6G_320M_CNTR_FREQ_SPACING == 0)))) {
			return TRUE;
		}
	}

	return FALSE;
}

/*
 * This function returns TRUE if both the chanspec can co-exist in PHY.
 * Addition to primary20 channel, the function checks for side band for 2g 40 channels
 */
bool
wf_chspec_coexist(chanspec_t chspec1, chanspec_t chspec2)
{
	bool same_primary;

	if ((chspec1 == NONWLAN_CHAN_SPEC) ||
		chspec2 == NONWLAN_CHAN_SPEC) {
		same_primary = (chspec1 == chspec2)? TRUE: FALSE;
		goto end;
	}

	if (CHSPEC_BAND(chspec1) != CHSPEC_BAND(chspec2)) {
		same_primary = FALSE;
		goto end;
	}
	same_primary = (wf_chspec_primary20_chan(chspec1) == wf_chspec_primary20_chan(chspec2));

	if (same_primary && CHSPEC_IS2G(chspec1)) {
	    if (CHSPEC_IS40(chspec1) && CHSPEC_IS40(chspec2)) {
	        same_primary = (CHSPEC_CTL_SB(chspec1) == CHSPEC_CTL_SB(chspec2));
		goto end;
	    }
	}
end:
	return same_primary;
}

/**
 * Create a 20MHz chanspec for the given band.
 *
 * This function returns a 20MHz chanspec in the given band.
 *
 * @param	channel   20MHz channel number
 * @param	band      a chanspec band (e.g. WL_CHANSPEC_BAND_2G)
 *
 * @return Returns a 20MHz chanspec, or IVNCHANSPEC in case of error.
 */
chanspec_t
wf_create_20MHz_chspec(uint channel, chanspec_band_t band)
{
	chanspec_t chspec;

	if (channel <= WL_CHANSPEC_CHAN_MASK &&
	    (band == WL_CHANSPEC_BAND_2G ||
	     band == WL_CHANSPEC_BAND_5G ||
	     band == WL_CHANSPEC_BAND_6G)) {
		chspec = band | WL_CHANSPEC_BW_20 | WL_CHANSPEC_CTL_SB_NONE | channel;
		if (!wf_chspec_valid(chspec)) {
			chspec = INVCHANSPEC;
		}
	} else {
		chspec = INVCHANSPEC;
	}

	return chspec;
}

/**
 * Returns the chanspec for a 40MHz channel given the primary 20MHz channel number,
 * the center channel number, and the band.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  center_channel   center channel of the 40MHz channel
 * @param  band             band of the 40MHz channel (chanspec_band_t value)
 *
 * The center_channel can be one of the 802.11 spec valid 40MHz chenter channels
 * in the given band.
 *
 * @return returns a 40MHz chanspec, or INVCHANSPEC in case of error
 */
chanspec_t
wf_create_40MHz_chspec(uint primary_channel, uint center_channel,
                       chanspec_band_t band)
{
	int sb;

	/* Calculate the sideband value for the center and primary channel.
	 * Will return -1 if not a valid pair for 40MHz
	 */
	sb = channel_to_sb(center_channel, primary_channel, WL_CHANSPEC_BW_40);

	/* return err if the sideband was bad or the center channel is not
	 * valid for the given band.
	 */
	if (sb < 0 || !wf_valid_40MHz_center_chan(center_channel, band)) {
		return INVCHANSPEC;
	}

	/* othewise construct and return the valid 40MHz chanspec */
	return (chanspec_t)(center_channel | WL_CHANSPEC_BW_40 | band |
	                    ((uint)sb << WL_CHANSPEC_CTL_SB_SHIFT));
}

/**
 * Returns the chanspec for a 40MHz channel given the primary 20MHz channel number,
 * the sub-band for the primary 20MHz channel, and the band.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  primary_subband  sub-band of the 20MHz primary channel (chanspec_subband_t value)
 * @param  band             band of the 40MHz channel (chanspec_band_t value)
 *
 * The primary channel and sub-band should describe one of the 802.11 spec valid
 * 40MHz channels in the given band.
 *
 * @return returns a 40MHz chanspec, or INVCHANSPEC in case of error
 */
chanspec_t
wf_create_40MHz_chspec_primary_sb(uint primary_channel, chanspec_subband_t primary_subband,
                                  chanspec_band_t band)
{
	uint center_channel;

	/* find the center channel */
	if (primary_subband == WL_CHANSPEC_CTL_SB_L) {
		center_channel = primary_channel + CH_10MHZ_APART;
	} else if (primary_subband == WL_CHANSPEC_CTL_SB_U) {
		center_channel = primary_channel - CH_10MHZ_APART;
	} else {
		return INVCHANSPEC;
	}

	return wf_create_40MHz_chspec(primary_channel, center_channel, band);
}

/**
 * Returns the chanspec for an 80MHz channel given the primary 20MHz channel number,
 * the center channel number, and the band.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  center_channel   center channel of the 80MHz channel
 * @param  band             band of the 80MHz channel (chanspec_band_t value)
 *
 * The center_channel can be one of {42, 58, 106, 122, 138, 155} for 5G,
 * or {7 + 16*X for 0 <= X <= 13} for 6G.
 *
 * @return returns an 80MHz chanspec, or INVCHANSPEC in case of error
 */
chanspec_t
wf_create_80MHz_chspec(uint primary_channel, uint center_channel,
                       chanspec_band_t band)
{
	int sb;

	/* Calculate the sideband value for the center and primary channel.
	 * Will return -1 if not a valid pair for 80MHz
	 */
	sb = channel_to_sb(center_channel, primary_channel, WL_CHANSPEC_BW_80);

	/* return err if the sideband was bad or the center channel is not
	 * valid for the given band.
	 */
	if (sb < 0 || !wf_valid_80MHz_center_chan(center_channel, band)) {
		return INVCHANSPEC;
	}

	/* othewise construct and return the valid 80MHz chanspec */
	return (chanspec_t)(center_channel | WL_CHANSPEC_BW_80 | band |
	                    ((uint)sb << WL_CHANSPEC_CTL_SB_SHIFT));
}

/**
 * Returns the chanspec for an 160MHz channel given the primary 20MHz channel number,
 * the center channel number, and the band.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  center_channel   center channel of the 160MHz channel
 * @param  band             band of the 160MHz channel (chanspec_band_t value)
 *
 * The center_channel can be one of {50, 114} for 5G,
 * or {15 + 32*X for 0 <= X <= 7} for 6G.
 *
 * @return returns an 160MHz chanspec, or INVCHANSPEC in case of error
 */
chanspec_t
wf_create_160MHz_chspec(uint primary_channel, uint center_channel, chanspec_band_t band)
{
	int sb;

	/* Calculate the sideband value for the center and primary channel.
	 * Will return -1 if not a valid pair for 160MHz
	 */
	sb = channel_to_sb(center_channel, primary_channel, WL_CHANSPEC_BW_160);

	/* return err if the sideband was bad or the center channel is not
	 * valid for the given band.
	 */
	if (sb < 0 || !wf_valid_160MHz_center_chan(center_channel, band)) {
		return INVCHANSPEC;
	}

	/* othewise construct and return the valid 160MHz chanspec */
	return (chanspec_t)(center_channel | WL_CHANSPEC_BW_160 | band |
	                    ((uint)sb << WL_CHANSPEC_CTL_SB_SHIFT));
}

/**
 * Returns the chanspec for an 80+80MHz channel given the primary 20MHz channel number,
 * the center channel numbers for each frequency segment, and the band.
 *
 * @param  primary_channel  primary 20 Mhz channel
 * @param  chan0            center channel number of one frequency segment
 * @param  chan1            center channel number of the other frequency segment
 * @param  band             band of the 80+80 MHz channel (chanspec_band_t value)
 *
 * Parameters chan0 and chan1 are valid 80 MHz center channel numbers for the given band.
 * The primary channel must be contained in one of the 80 MHz channels. This routine
 * will determine which frequency segment is the primary 80 MHz segment.
 *
 * @return returns an 80+80 MHz chanspec, or INVCHANSPEC in case of error
 *
 * Refer to 802.11-2016 section 21.3.14 "Channelization".
 */
chanspec_t
wf_create_8080MHz_chspec(uint primary_channel, uint chan0, uint chan1,
                       chanspec_band_t band)
{
	int sb = 0;
	chanspec_t chanspec = 0;
	int chan0_id = -1, chan1_id = -1;
	int seg0, seg1;

	/* frequency segments need to be non-contiguous, so the channel separation needs
	 * to be greater than 80MHz
	 */
	if ((uint)ABS((int)(chan0 - chan1)) <= CH_80MHZ_APART) {
		return INVCHANSPEC;
	}

	if (band == WL_CHANSPEC_BAND_5G) {
		chan0_id = channel_80mhz_to_id(chan0);
		chan1_id = channel_80mhz_to_id(chan1);
	} else if (band == WL_CHANSPEC_BAND_6G) {
		chan0_id = channel_6g_80mhz_to_id(chan0);
		chan1_id = channel_6g_80mhz_to_id(chan1);
	}

	/* make sure the channel numbers were valid */
	if (chan0_id == -1 || chan1_id == -1) {
		return INVCHANSPEC;
	}

	/* does the primary channel fit with the 1st 80MHz channel ? */
	sb = channel_to_sb(chan0, primary_channel, WL_CHANSPEC_BW_80);
	if (sb >= 0) {
		/* yes, so chan0 is frequency segment 0, and chan1 is seg 1 */
		seg0 = chan0_id;
		seg1 = chan1_id;
	} else {
		/* no, so does the primary channel fit with the 2nd 80MHz channel ? */
		sb = channel_to_sb(chan1, primary_channel, WL_CHANSPEC_BW_80);
		if (sb < 0) {
			/* no match for pri_ch to either 80MHz center channel */
			return INVCHANSPEC;
		}
		/* swapped, so chan1 is frequency segment 0, and chan0 is seg 1 */
		seg0 = chan1_id;
		seg1 = chan0_id;
	}

	chanspec = ((seg0 << WL_CHANSPEC_CHAN0_SHIFT) |
	            (seg1 << WL_CHANSPEC_CHAN1_SHIFT) |
	            (sb << WL_CHANSPEC_CTL_SB_SHIFT) |
	            WL_CHANSPEC_BW_8080 |
	            band);

	return chanspec;
}

/**
 * Returns the chanspec for an 320MHz channel given the primary 20MHz channel number,
 * the center channel number, and the band.
 *
 * @param  primary_channel  primary 20 Mhz channel
 * @param  chan             center channel number
 * @param  band             band of the 320 MHz channel (chanspec_band_t value)
 *
 * Parameters chan is valid 320 MHz center channel numbers for the given band.
 * The primary channel must be contained in one of the 320 MHz channels.
 *
 * @return returns an 320 MHz chanspec, or INVCHANSPEC in case of error
 *
 * Refer to <TBD> "Channelization".
 */
chanspec_t
wf_create_320MHz_chspec(uint primary_channel, uint center_channel,
	chanspec_band_t band)
{
	int sb = 0;
	chanspec_t chanspec = 0;
	int chan_id = -1;

	if (band == WL_CHANSPEC_BAND_6G) {
		chan_id = channel_6g_320mhz_to_id(center_channel);
	}

	/* make sure the channel number were valid */
	if (chan_id == -1) {
		return INVCHANSPEC;
	}

	/* Calculate the sideband value for the center and primary channel.
	 * Will return -1 if not a valid pair for 320MHz
	 */
	sb = channel_to_sb(center_channel, primary_channel, WL_CHANSPEC_BW_320);

	/* return err if the sideband was bad or the center channel is not
	 * valid for the given band.
	 */
	if (sb < 0 || !wf_valid_320MHz_center_chan(center_channel, band)) {
		return INVCHANSPEC;
	}

	chanspec = ((chan_id << WL_CHANSPEC_320_CHAN_SHIFT) |
	            (sb << WL_CHANSPEC_320_SB_SHIFT) |
	            WL_CHANSPEC_BW_320 |
	            band);

	return chanspec;
}

/**
 * Returns the chanspec given the primary 20MHz channel number,
 * the center channel number, channel width, and the band. The channel width
 * must be 20, 40, 80, 160, 320 MHz.
 * 80+80 MHz chanspec creation is not handled by this function,
 * use wf_create_8080MHz_chspec() instead.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  center_channel   center channel of the channel
 * @param  bw               width of the channel (chanspec_bw_t)
 * @param  band             chanspec band of channel  (chanspec_band_t)
 *
 * The center_channel can be one of the 802.11 spec valid center channels
 * for the given bandwidth in the given band.
 *
 * @return returns a chanspec, or INVCHANSPEC in case of error
 */
chanspec_t
wf_create_chspec(uint primary_channel, uint center_channel,
                 chanspec_bw_t bw, chanspec_band_t band)
{
	chanspec_t chspec = INVCHANSPEC;
	int sb = -1;
	uint sb_shift;

	/* 20MHz channels have matching center and primary channels */
	if (bw == WL_CHANSPEC_BW_20 && primary_channel == center_channel) {

		sb = 0;

	} else if (bw == WL_CHANSPEC_BW_40 ||
		bw == WL_CHANSPEC_BW_80 ||
		bw == WL_CHANSPEC_BW_160 ||
		WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {

		/* calculate the sub-band index */
		sb = channel_to_sb(center_channel, primary_channel, bw);
	}

	/* if we have a good sub-band, assemble the chanspec, and use wf_chspec_valid()
	 * to check it for correctness
	 */
	if (sb >= 0) {
		if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
			if (band == WL_CHANSPEC_BAND_6G) {
				center_channel = channel_6g_320mhz_to_id(center_channel);
				sb_shift = WL_CHANSPEC_320_SB_SHIFT;
			} else {
				return INVCHANSPEC;
			}
		} else {
			sb_shift = WL_CHANSPEC_CTL_SB_SHIFT;
		}
		chspec = center_channel | band | bw |
		        ((uint)sb << sb_shift);
		if (!wf_chspec_valid(chspec)) {
			chspec = INVCHANSPEC;
		}
	}

	return chspec;
}

/**
 * Returns the chanspec given the primary 20MHz channel number,
 * channel width, and the band.
 *
 * @param  primary_channel  primary 20Mhz channel
 * @param  bw               width of the channel (chanspec_bw_t)
 * @param  band             chanspec band of channel  (chanspec_band_t)
 *
 * @return returns a chanspec, or INVCHANSPEC in case of error
 *
 * This function is a similar to wf_create_chspec() but does not require the
 * center_channel parameter. As a result, it can not create 40MHz channels on
 * the 2G band.
 *
 * This function supports creating 20MHz bandwidth chanspecs on any band.
 *
 * For the 2GHz band, 40MHz channels overlap, so two 40MHz channels may
 * have the same primary 20MHz channel. This function will return INVCHANSPEC
 * whenever called with a bandwidth of 40MHz or wider for the 2GHz band.
 *
 * 5GHz and 6GHz bands have non-overlapping 40/80/160 MHz channels, so a
 * 20MHz primary channel uniquely specifies a wider channel in a given band.
 * For the 6GHz band, as 320MHz channels overlaps, if OVERLAPPED320 is TRUE.
 * 320Mhz chanspecs from center channel set { 63, 127, 191 } is generated.
 *
 * 80+80MHz channels also cannot be uniquely defined. This function will return
 * INVCHANSPEC whenever bandwidth of WL_CHANSPEC_BW_8080.
 */
chanspec_t
wf_create_chspec_from_primary(uint primary_channel, chanspec_bw_t bw, chanspec_band_t band,
	uint16 flags)
{
	chanspec_t chspec = INVCHANSPEC;

	if (bw == WL_CHANSPEC_BW_20) {
		chspec = wf_create_20MHz_chspec(primary_channel, band);
	} else if (band == WL_CHANSPEC_BAND_2G) {
		/* 2G 40MHz cannot be uniquely identified by the primary channel.
		 * Return INVAL for any channel given. Or if bw != 20
		 */
	} else if (band == WL_CHANSPEC_BAND_5G) {
		/* For 5GHz, use the lookup tables for valid 40/80/160 center channels
		 * and search for a center channel compatible with the given primary channel.
		 */
		const uint8 *center_ch = NULL;
		uint num_ch, i;

		if (bw == WL_CHANSPEC_BW_40) {
			center_ch = wf_5g_40m_chans;
			num_ch = WF_NUM_5G_40M_CHANS;
		} else if (bw == WL_CHANSPEC_BW_80) {
			center_ch = wf_5g_80m_chans;
			num_ch = WF_NUM_5G_80M_CHANS;
		} else if (bw == WL_CHANSPEC_BW_160) {
			center_ch = wf_5g_160m_chans;
			num_ch = WF_NUM_5G_160M_CHANS;
		} else {
			num_ch = 0;
		}

		for (i = 0; i < num_ch; i ++) {
			chspec = wf_create_chspec(primary_channel, center_ch[i], bw, band);
			if (chspec != INVCHANSPEC) {
				break;
			}
		}
	}
	else if (band == WL_CHANSPEC_BAND_6G) {
		bool ol320 = (flags & WF_CHANSPEC_FLAG_OVERLAPPED320);
		uint center = wf_6g_get_center_chan_from_primary(primary_channel, bw, ol320);
		if (center != INVCHANNEL) {
			chspec = wf_create_chspec(primary_channel, center, bw, band);
		}
	}

	return chspec;
}

/**
 * Return the primary 20MHz channel.
 *
 * This function returns the channel number of the primary 20MHz channel. For
 * 20MHz channels this is just the channel number. For 40MHz or wider channels
 * it is the primary 20MHz channel specified by the chanspec.
 *
 * @param	chspec    input chanspec
 *
 * @return Returns the channel number of the primary 20MHz channel
 */
uint8
BCMFASTPATH(wf_chspec_primary20_chan)(chanspec_t chspec)
{
	uint center_chan = INVCHANNEL;
	chanspec_bw_t bw;
	uint sb;

	ASSERT_FP(!wf_chspec_malformed(chspec));

	/* Is there a sideband ? */
	if (CHSPEC_IS20(chspec)) {
		return wf_chspec_center_channel(chspec);
	} else {
		sb = wf_chspec_get_primary_sb(chspec);

		if (CHSPEC_IS8080(chspec)) {
			/* For an 80+80 MHz channel, the sideband 'sb' field is an 80 MHz sideband
			 * (LL, LU, UL, LU) for the 80 MHz frequency segment 0.
			 */

			/* use bw 80MHz for the primary channel lookup */
			bw = WL_CHANSPEC_BW_80;

			/* convert from channel index to channel number */
			if (CHSPEC_IS5G(chspec)) {
				center_chan = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
			} else if (CHSPEC_IS6G(chspec)) {
				center_chan = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
			}
		} else if (CHSPEC_IS320(chspec)) {
			/* use bw 320MHz for the primary channel lookup */
			bw = WL_CHANSPEC_BW_320;

			/* convert from channel index to channel number */
			if (CHSPEC_IS6G(chspec)) {
				center_chan = wf_chspec_6G_id320_to_ch(WL_CHSPEC_320_CHAN(chspec));
			}
			/* What to return otherwise? */
		}
		else {
			bw = CHSPEC_BW(chspec);
			center_chan = wf_chspec_center_channel(chspec);
		}

		return (uint8)(channel_to_primary20_chan((uint8)center_chan, bw, sb));
	}
}

/**
 * Return the bandwidth string for a given chanspec
 *
 * This function returns the bandwidth string for the passed chanspec.
 *
 * @param	chspec    input chanspec
 *
 * @return Returns the bandwidth string:
 *         "320", "20", "20", "40", "80", "160", "80+80",
 */
const char *
BCMRAMFN(wf_chspec_to_bw_str)(chanspec_t chspec)
{
	return wf_chspec_bw_str[WL_CHSPEC_BW(chspec)];
}

/**
 * Return the primary 20MHz chanspec of a given chanspec
 *
 * This function returns the chanspec of the primary 20MHz channel. For 20MHz
 * channels this is just the chanspec. For 40MHz or wider channels it is the
 * chanspec of the primary 20MHz channel specified by the chanspec.
 *
 * @param	chspec    input chanspec
 *
 * @return Returns the chanspec of the primary 20MHz channel
 */
chanspec_t
wf_chspec_primary20_chspec(chanspec_t chspec)
{
	chanspec_t pri_chspec = chspec;
	uint8 pri_chan;

	ASSERT(!wf_chspec_malformed(chspec));

	/* Is there a sideband ? */
	if (!CHSPEC_IS20(chspec)) {
		pri_chan = wf_chspec_primary20_chan(chspec);
		pri_chspec = pri_chan | WL_CHANSPEC_BW_20;
		pri_chspec |= CHSPEC_BAND(chspec);
	}
	return pri_chspec;
}

/* return chanspec given primary 20MHz channel and bandwidth
 * return 0 on error
 * does not support 6G
 */
uint16
wf_channel2chspec(uint pri_ch, uint bw)
{
	uint16 chspec;
	const uint8 *center_ch = NULL;
	int num_ch = 0;
	int sb = -1;
	int i = 0;

	chspec = ((pri_ch <= CH_MAX_2G_CHANNEL) ? WL_CHANSPEC_BAND_2G : WL_CHANSPEC_BAND_5G);

	chspec |= bw;

	if (bw == WL_CHANSPEC_BW_40) {
		center_ch = wf_5g_40m_chans;
		num_ch = WF_NUM_5G_40M_CHANS;
	} else if (bw == WL_CHANSPEC_BW_80) {
		center_ch = wf_5g_80m_chans;
		num_ch = WF_NUM_5G_80M_CHANS;
	} else if (bw == WL_CHANSPEC_BW_160) {
		center_ch = wf_5g_160m_chans;
		num_ch = WF_NUM_5G_160M_CHANS;
	} else if (bw == WL_CHANSPEC_BW_20) {
		chspec |= pri_ch;
		return chspec;
	} else {
		return 0;
	}

	for (i = 0; i < num_ch; i ++) {
		sb = channel_to_sb(center_ch[i], pri_ch, (chanspec_bw_t)bw);
		if (sb >= 0) {
			chspec |= center_ch[i];
			chspec |= (sb << WL_CHANSPEC_CTL_SB_SHIFT);
			break;
		}
	}

	/* check for no matching sb/center */
	if (sb < 0) {
		return 0;
	}

	return chspec;
}

/**
 * Return the primary 40MHz chanspec or a 40MHz or wider channel
 *
 * This function returns the chanspec for the primary 40MHz of an 80MHz or wider channel.
 * The primary 40MHz channel is the 40MHz sub-band that contains the primary 20MHz channel.
 * The primary 20MHz channel of the returned 40MHz chanspec is the same as the primary 20MHz
 * channel of the input chanspec.
 *
 * @param	chspec    input chanspec
 *
 * @return Returns the chanspec of the primary 20MHz channel
 */
chanspec_t
wf_chspec_primary40_chspec(chanspec_t chspec)
{
	chanspec_t chspec40 = chspec;
	uint center_chan;
	uint sb;

	ASSERT(!wf_chspec_malformed(chspec));

	/* if the chanspec is > 80MHz, use the helper routine to find the primary 80 MHz channel */
	if (CHSPEC_IS8080(chspec) || CHSPEC_IS160(chspec)) {
		chspec = wf_chspec_primary80_chspec(chspec);
	}

	/* determine primary 40 MHz sub-channel of an 80 MHz chanspec */
	if (CHSPEC_IS80(chspec)) {
		center_chan = wf_chspec_center_channel(chspec);
		sb = CHSPEC_CTL_SB(chspec);

		if (sb < WL_CHANSPEC_CTL_SB_UL) {
			/* Primary 40MHz is on lower side */
			center_chan -= CH_20MHZ_APART;
			/* sideband bits are the same for LL/LU and L/U */
		} else {
			/* Primary 40MHz is on upper side */
			center_chan += CH_20MHZ_APART;
			/* sideband bits need to be adjusted by UL offset */
			sb -= WL_CHANSPEC_CTL_SB_UL;
		}

		/* Create primary 40MHz chanspec */
		chspec40 = (CHSPEC_BAND(chspec) | WL_CHANSPEC_BW_40 |
		            sb | center_chan);
	}

	return chspec40;
}

/**
 * Return the chanspec band for a given frequency.
 *
 * @param  freq		frequency in MHz of the channel center
 *
 * @return  Returns chanspec band of frequency (chanspec_band_t)
 */
chanspec_band_t
wf_mhz2chanspec_band(uint freq)
{
	chanspec_band_t band = INVCHANSPEC;

	if (freq >= 2400u && freq <= 2500u) {
		band = WL_CHANSPEC_BAND_2G;
	} else if (freq >= 5000u && freq < 5935u) {
		band = WL_CHANSPEC_BAND_5G;
	} else if (freq >= 5935u && freq <= 7205u) {
		band = WL_CHANSPEC_BAND_6G;
	}

	return band;
}

/**
 * Return the channel number for a given frequency and base frequency.
 *
 * @param   freq            frequency in MHz of the channel center
 * @param   start_factor    starting base frequency in 500 KHz units
 *
 * @return  Returns a channel number > 0, or -1 on error
 *
 * The returned channel number is relative to the given base frequency.
 *
 * The base frequency is specified as (start_factor * 500 kHz).
 * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G, and WF_CHAN_FACTOR_6_G are
 * defined for 2.4 GHz, 5 GHz, and 6 GHz bands.
 *
 * If the given base frequency is zero these base frequencies are assumed:
 *
 *              freq (GHz)  -> assumed base freq (GHz)
 *  2G band   2.4   - 2.5      2.407
 *  5G band   5.0   - 5.940    5.000
 *  6G band   5.940 - 7.205    5.940
 *
 * It is an error if the start_factor is zero and the freq is not in one of
 * these ranges.
 *
 * The returned channel will be in the range [1, 14] in the 2.4 GHz band,
 * [1, 253] for 6 GHz band, or [1, 200] otherwise.
 *
 * It is an error if the start_factor is WF_CHAN_FACTOR_2_4_G and the
 * frequency is not a 2.4 GHz channel. For any other start factor the frequency
 * must be an even 5 MHz multiple greater than the base frequency.
 *
 * For a start_factor WF_CHAN_FACTOR_6_G, the frequency may be up to 7.205 MHz
 * (channel 253). For any other start_factor, the frequence can be up to
 * 1 GHz from the base freqency (channel 200).
 *
 * Reference 802.11-2016, section 17.3.8.3 and section 16.3.6.3
 */
int
wf_mhz2channel(uint freq, uint start_factor)
{
	int ch = -1;
	uint base;
	int offset;

	/* take the default channel start frequency */
	if (start_factor == 0) {
		if (freq >= 2400 && freq <= 2500) {
			start_factor = WF_CHAN_FACTOR_2_4_G;
		} else if (freq >= 5000 && freq < 5935) {
			start_factor = WF_CHAN_FACTOR_5_G;
		} else if (freq >= 5935 && freq <= 7205) {
			start_factor = WF_CHAN_FACTOR_6_G;
		}
	}

	if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G) {
		return 14;
	} else if (freq == 5935 && start_factor == WF_CHAN_FACTOR_6_G) {
		/* channel #2 is an oddball, 10MHz below chan #1 */
		return 2;
	} else if (freq == 5960 && start_factor == WF_CHAN_FACTOR_6_G) {
		/* do not return ch #2 for the convetional location that #2 would appear */
		return -1;
	}

	base = start_factor / 2;

	if (freq < base) {
		return -1;
	}

	offset = freq - base;
	ch = offset / 5;

	/* check that frequency is a 5MHz multiple from the base */
	if (offset != (ch * 5))
		return -1;

	/* channel range checks */
	if (start_factor == WF_CHAN_FACTOR_2_4_G) {
		/* 2G should only be up to 13 here as 14 is
		 * handled above as it is a non-5MHz offset
		 */
		if (ch > 13) {
			ch = -1;
		}
	}
	else if (start_factor == WF_CHAN_FACTOR_6_G) {
		/* 6G has a higher channel range than 5G channelization specifies [1,200] */
		if ((uint)ch > CH_MAX_6G_CHANNEL) {
			ch = -1;
		}
	} else if (ch > 200) {
			ch = -1;
	}

	return ch;
}

/**
 * Return the center frequency in MHz of the given channel and base frequency.
 *
 * The channel number is interpreted relative to the given base frequency.
 *
 * The valid channel range is [1, 14] in the 2.4 GHz band, [1,253] in the 6 GHz
 * band, and [1, 200] otherwise.
 * The base frequency is specified as (start_factor * 500 kHz).
 * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G, and WF_CHAN_FACTOR_6_G are
 * defined for 2.4 GHz, 5 GHz, and 6 GHz bands.
 * The channel range of [1, 14] is only checked for a start_factor of
 * WF_CHAN_FACTOR_2_4_G (4814).
 * Odd start_factors produce channels on .5 MHz boundaries, in which case
 * the answer is rounded down to an integral MHz.
 * -1 is returned for an out of range channel.
 *
 * Reference 802.11-2016, section 17.3.8.3 and section 16.3.6.3
 *
 * @param	channel       input channel number
 * @param	start_factor  base frequency in 500 kHz units, e.g. 10000 for 5 GHz
 *
 * @return Returns a frequency in MHz
 *
 * @see  WF_CHAN_FACTOR_2_4_G
 * @see  WF_CHAN_FACTOR_5_G
 * @see  WF_CHAN_FACTOR_6_G
 */
int
BCMPOSTTRAPFN(wf_channel2mhz)(uint ch, uint start_factor)
{
	int freq;

	if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
	    (start_factor == WF_CHAN_FACTOR_6_G && (ch < 1 || ch > 253)) ||
	    (start_factor != WF_CHAN_FACTOR_6_G && (ch < 1 || ch > 200))) {
		freq = -1;
	} else if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14)) {
		freq = 2484;
	} else if ((start_factor == WF_CHAN_FACTOR_6_G) && (ch == 2)) {
		freq = 5935;
	} else {
		freq = ch * 5 + start_factor / 2;
	}

	return freq;
}

static const uint16 sidebands[] = {
	WL_CHANSPEC_CTL_SB_LLL, WL_CHANSPEC_CTL_SB_LLU,
	WL_CHANSPEC_CTL_SB_LUL, WL_CHANSPEC_CTL_SB_LUU,
	WL_CHANSPEC_CTL_SB_ULL, WL_CHANSPEC_CTL_SB_ULU,
	WL_CHANSPEC_CTL_SB_UUL, WL_CHANSPEC_CTL_SB_UUU
};

/*
 * Returns the chanspec 80Mhz channel corresponding to the following input
 * parameters
 *
 *	primary_channel - primary 20Mhz channel
 *	center_channel   - center frequecny of the 80Mhz channel
 *
 * The center_channel can be one of {42, 58, 106, 122, 138, 155}
 *
 * returns INVCHANSPEC in case of error
 *
 * does not support 6G
 */
chanspec_t
wf_chspec_80(uint8 center_channel, uint8 primary_channel)
{

	chanspec_t chanspec = INVCHANSPEC;
	chanspec_t chanspec_cur;
	uint i;

	for (i = 0; i < WF_NUM_SIDEBANDS_80MHZ; i++) {
		chanspec_cur = CH80MHZ_CHSPEC(center_channel, sidebands[i]);
		if (primary_channel == wf_chspec_primary20_chan(chanspec_cur)) {
			chanspec = chanspec_cur;
			break;
		}
	}
	/* If the loop ended early, we are good, otherwise we did not
	* find a 80MHz chanspec with the given center_channel that had a primary channel
	*matching the given primary_channel.
	*/
	return chanspec;
}

/*
 * Returns the 80+80 chanspec corresponding to the following input parameters
 *
 *    primary_20mhz - Primary 20 MHz channel
 *    chan0 - center channel number of one frequency segment
 *    chan1 - center channel number of the other frequency segment
 *
 * Parameters chan0 and chan1 are channel numbers in {42, 58, 106, 122, 138, 155}.
 * The primary channel must be contained in one of the 80MHz channels. This routine
 * will determine which frequency segment is the primary 80 MHz segment.
 *
 * Returns INVCHANSPEC in case of error.
 *
 * Refer to 802.11-2016 section 22.3.14 "Channelization".
 *
 * does not support 6G
 */
chanspec_t
wf_chspec_get8080_chspec(uint8 primary_20mhz, uint8 chan0, uint8 chan1)
{
	int sb = 0;
	uint16 chanspec = 0;
	int chan0_id = 0, chan1_id = 0;
	int seg0, seg1;

	chan0_id = channel_80mhz_to_id(chan0);
	chan1_id = channel_80mhz_to_id(chan1);

	/* make sure the channel numbers were valid */
	if (chan0_id == -1 || chan1_id == -1)
		return INVCHANSPEC;

	/* does the primary channel fit with the 1st 80MHz channel ? */
	sb = channel_to_sb(chan0, primary_20mhz, WL_CHANSPEC_BW_80);
	if (sb >= 0) {
		/* yes, so chan0 is frequency segment 0, and chan1 is seg 1 */
		seg0 = chan0_id;
		seg1 = chan1_id;
	} else {
		/* no, so does the primary channel fit with the 2nd 80MHz channel ? */
		sb = channel_to_sb(chan1, primary_20mhz, WL_CHANSPEC_BW_80);
		if (sb < 0) {
			/* no match for pri_ch to either 80MHz center channel */
			return INVCHANSPEC;
		}
		/* swapped, so chan1 is frequency segment 0, and chan0 is seg 1 */
		seg0 = chan1_id;
		seg1 = chan0_id;
	}

	chanspec = ((seg0 << WL_CHANSPEC_CHAN0_SHIFT) |
	            (seg1 << WL_CHANSPEC_CHAN1_SHIFT) |
	            (sb << WL_CHANSPEC_CTL_SB_SHIFT) |
	            WL_CHANSPEC_BW_8080 |
	            WL_CHANSPEC_BAND_5G);

	return chanspec;
}

/*
 * Returns the center channel of the primary 80 MHz sub-band of the provided chanspec
 */
uint8
wf_chspec_primary80_channel(chanspec_t chanspec)
{
	chanspec_t primary80_chspec;
	uint8 primary80_chan;

	primary80_chspec = wf_chspec_primary80_chspec(chanspec);

	if (primary80_chspec == INVCHANSPEC) {
		primary80_chan = INVCHANNEL;
	} else {
		primary80_chan = wf_chspec_center_channel(primary80_chspec);
	}

	return primary80_chan;
}

/*
 * Returns the center channel of the secondary 80 MHz sub-band of the provided chanspec
 */
uint8
wf_chspec_secondary80_channel(chanspec_t chanspec)
{
	chanspec_t secondary80_chspec;
	uint8 secondary80_chan;

	secondary80_chspec = wf_chspec_secondary80_chspec(chanspec);

	if (secondary80_chspec == INVCHANSPEC) {
		secondary80_chan = INVCHANNEL;
	} else {
		secondary80_chan = wf_chspec_center_channel(secondary80_chspec);
	}

	return secondary80_chan;
}

/*
 * Returns the chanspec for the primary 80MHz sub-band of a 320MHz or 160MHz or
 * 80+80MHz channel
 */
chanspec_t
wf_chspec_primary80_chspec(chanspec_t chspec)
{
	chanspec_t chspec80 = INVCHANSPEC;
	uint center_chan = INVCHANNEL;
	uint sb;

	ASSERT(!wf_chspec_malformed(chspec));

	/* if the chanspec is > 160MHz, use helper routine to find the primary 160 MHz channel */
	if (CHSPEC_IS320(chspec)) {
		chspec = wf_chspec_primary160_chspec(chspec);
	}

	if (CHSPEC_IS80(chspec)) {
		chspec80 = chspec;
	} else if (CHSPEC_IS8080(chspec)) {
		sb = CHSPEC_CTL_SB(chspec);

		/* primary sub-band is stored in seg0 */
		if (CHSPEC_IS5G(chspec)) {
			center_chan = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
		} else if (CHSPEC_IS6G(chspec)) {
			center_chan = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN0(chspec));
		}

		if (center_chan != INVCHANNEL) {
			/* Create primary 80MHz chanspec */
			chspec80 = (CHSPEC_BAND(chspec) |
			            WL_CHANSPEC_BW_80 |
			            sb |
			            center_chan);
		}
	}
	else if (CHSPEC_IS160(chspec)) {
		center_chan = wf_chspec_center_channel(chspec);
		sb = CHSPEC_CTL_SB(chspec);

		if (sb < WL_CHANSPEC_CTL_SB_ULL) {
			/* Primary 80MHz is on lower side */
			center_chan -= CH_40MHZ_APART;
		} else {
			/* Primary 80MHz is on upper side */
			center_chan += CH_40MHZ_APART;
			sb -= WL_CHANSPEC_CTL_SB_ULL;
		}

		if (center_chan != INVCHANNEL) {
			/* Create primary 80MHz chanspec */
			chspec80 = (CHSPEC_BAND(chspec) |
			            WL_CHANSPEC_BW_80 |
			            sb |
			            center_chan);
		}
	}

	return chspec80;
}

/*
 * Returns the chanspec for the secondary 80MHz sub-band of an 160MHz or 80+80 channel
 */
chanspec_t
wf_chspec_secondary80_chspec(chanspec_t chspec)
{
	chanspec_t chspec80 = INVCHANSPEC;
	uint center_chan = INVCHANNEL;

	ASSERT(!wf_chspec_malformed(chspec));

	if (CHSPEC_IS8080(chspec)) {
		/* secondary sub-band is stored in seg1 */
		if (CHSPEC_IS5G(chspec)) {
			center_chan = wf_chspec_5G_id80_to_ch(WL_CHSPEC_CHAN1(chspec));
		} else if (CHSPEC_IS6G(chspec)) {
			center_chan = wf_chspec_6G_id80_to_ch(WL_CHSPEC_CHAN1(chspec));
		}

		if (center_chan != INVCHANNEL) {
			/* Create secondary 80MHz chanspec */
			chspec80 = (CHSPEC_BAND(chspec) |
			            WL_CHANSPEC_BW_80 |
			            WL_CHANSPEC_CTL_SB_LL |
			            center_chan);
		}
	}
	else if (CHSPEC_IS160(chspec)) {
		center_chan = wf_chspec_center_channel(chspec);

		if (CHSPEC_CTL_SB(chspec) < WL_CHANSPEC_CTL_SB_ULL) {
			/* Primary 80MHz is on lower side, so the secondary is on
			 * the upper side
			 */
			center_chan += CH_40MHZ_APART;
		} else {
			/* Primary 80MHz is on upper side, so the secondary is on
			 * the lower side
			 */
			center_chan -= CH_40MHZ_APART;
		}

		if (center_chan != INVCHANNEL) {
			/* Create secondary 80MHz chanspec */
			chspec80 = (CHSPEC_BAND(chspec) |
			            WL_CHANSPEC_BW_80 |
			            WL_CHANSPEC_CTL_SB_LL |
			            center_chan);
		}
	}

	return chspec80;
}

/*
 * For 160MHz or 80P80 chanspec, set ch[0]/ch[1] to be the low/high 80 Mhz channels
 *
 * For 20/40/80MHz chanspec, set ch[0] to be the center freq, and chan[1]=-1
 */
void
wf_chspec_get_80p80_channels(chanspec_t chspec, uint8 *ch)
{

	if (CHSPEC_IS160(chspec)) {
		uint8 center_chan = wf_chspec_center_channel(chspec);
		ch[0] = center_chan - CH_40MHZ_APART;
		ch[1] = center_chan + CH_40MHZ_APART;
	}
	else {
		/* for 20, 40, and 80 Mhz */
		ch[0] = wf_chspec_center_channel(chspec);
		ch[1] = -1;
	}
	return;

}

/*
 * Returns the center channel of the primary 160MHz sub-band of the provided chanspec
 */
uint8
wf_chspec_primary160_channel(chanspec_t chanspec)
{
	chanspec_t primary160_chspec;
	uint8 primary160_chan;

	primary160_chspec = wf_chspec_primary160_chspec(chanspec);

	if (primary160_chspec == INVCHANSPEC) {
		primary160_chan = INVCHANNEL;
	} else {
		primary160_chan = wf_chspec_center_channel(primary160_chspec);
	}

	return primary160_chan;
}

/*
 * Returns the chanspec for the primary 160MHz sub-band of an 320MHz channel
 */
chanspec_t
wf_chspec_primary160_chspec(chanspec_t chspec)
{
	chanspec_t chspec160 = INVCHANSPEC;
	uint center_chan = INVCHANNEL;
	uint sb;

	ASSERT(!wf_chspec_malformed(chspec));

	if (CHSPEC_IS160(chspec)) {
		chspec160 = chspec;
	} else if (CHSPEC_IS320(chspec)) {
		center_chan = wf_chspec_320_id2cch(chspec);
		sb = CHSPEC_320_SB(chspec) >> WL_CHANSPEC_320_SB_SHIFT;

		if (sb < 8u) {
			/* Primary 160MHz is on lower side */
			center_chan -= CH_80MHZ_APART;
		} else {
			/* Primary 160MHz is on upper side */
			center_chan += CH_80MHZ_APART;
			sb -= 8u;
		}

		if (center_chan != INVCHANNEL) {
			/* Create primary 160MHz chanspec */
			chspec160 = (CHSPEC_BAND(chspec) |
			             WL_CHANSPEC_BW_160 |
			             (sb << WL_CHANSPEC_CTL_SB_SHIFT) |
			             center_chan);
		}
	}

	return chspec160;
}

/*
 * Returns the center channel of the secondary 160MHz sub-band of the provided chanspec
 */
uint8
wf_chspec_secondary160_channel(chanspec_t chanspec)
{
	chanspec_t secondary160_chspec;
	uint8 secondary160_chan;

	secondary160_chspec = wf_chspec_secondary160_chspec(chanspec);

	if (secondary160_chspec == INVCHANSPEC) {
		secondary160_chan = INVCHANNEL;
	} else {
		secondary160_chan = wf_chspec_center_channel(secondary160_chspec);
	}

	return secondary160_chan;
}

/*
 * Returns the chanspec for the secondary 160MHz sub-band of an 320MHz channel
 */
chanspec_t
wf_chspec_secondary160_chspec(chanspec_t chspec)
{
	chanspec_t chspec160 = INVCHANSPEC;
	uint center_chan = INVCHANNEL;
	uint sb;

	ASSERT(!wf_chspec_malformed(chspec));

	if (CHSPEC_IS160(chspec)) {
		chspec160 = chspec;
	} else if (CHSPEC_IS320(chspec)) {
		center_chan = wf_chspec_320_id2cch(chspec);
		sb = CHSPEC_320_SB(chspec) >> WL_CHANSPEC_320_SB_SHIFT;

		if (sb < 8u) {
			/* Primary 160MHz is on lower side, so the secondary is on
			 * the upper side
			 */
			center_chan += CH_80MHZ_APART;
			sb += 8u;
		} else {
			/* Primary 160MHz is on upper side, so the secondary is on
			 * the lower side
			 */
			center_chan -= CH_80MHZ_APART;
			sb -= 8u;
		}

		if (center_chan != INVCHANNEL) {
			/* Create secondary 160MHz chanspec */
			chspec160 = (CHSPEC_BAND(chspec) |
			             WL_CHANSPEC_BW_160 |
			             (sb << WL_CHANSPEC_CTL_SB_SHIFT) |
			             center_chan);
		}
	}

	return chspec160;
}

/* Populates array with all 20MHz side bands of a given chanspec_t in the following order:
 *		primary20, secondary20, two secondary40s, four secondary80s.
 *    'chspec' is the chanspec of interest
 *    'pext' must point to an uint8 array of long enough to hold all side bands of the given chspec
 *
 * Works with 20, 40, 80, and 160MHz chspec
 */
void
wf_get_all_ext(chanspec_t chspec, uint8 *pext)
{
	chanspec_t t = (CHSPEC_IS160(chspec)) ? /* if bw > 80MHz */
		wf_chspec_primary80_chspec(chspec) : (chspec); /* extract primary 80 */
	/* primary20 channel as first element */
	uint8 pri_ch = (pext)[0] = wf_chspec_primary20_chan(t);

	if (CHSPEC_IS20(chspec)) {
		return; /* nothing more to do since 20MHz chspec */
	}
	/* 20MHz EXT */
	(pext)[1] = (IS_CTL_IN_L20(t) ? pri_ch + CH_20MHZ_APART : pri_ch - CH_20MHZ_APART);

	if (CHSPEC_IS40(chspec)) {
		return; /* nothing more to do since 40MHz chspec */
	}
	/* center 40MHz EXT */
	t = wf_channel2chspec((IS_CTL_IN_L40(chspec) ?
		pri_ch + CH_40MHZ_APART : pri_ch - CH_40MHZ_APART), WL_CHANSPEC_BW_40);
	GET_ALL_SB(t, &((pext)[2])); /* get the 20MHz side bands in 40MHz EXT */

	if (CHSPEC_IS80(chspec)) {
		return; /* nothing more to do since 80MHz chspec */
	}
	t = CH80MHZ_CHSPEC(wf_chspec_secondary80_channel(chspec), WL_CHANSPEC_CTL_SB_LLL);
	/* get the 20MHz side bands in 80MHz EXT (secondary) */
	GET_ALL_SB(t, &((pext)[4]));
}

/*
 * Given two chanspecs, returns true if they overlap.
 * (Overlap: At least one 20MHz subband is common between the two chanspecs provided)
 */
bool wf_chspec_overlap(chanspec_t chspec0, chanspec_t chspec1)
{
	uint8 ch0, ch1;

	if (CHSPEC_BAND(chspec0) != CHSPEC_BAND(chspec1)) {
		return FALSE;
	}

	FOREACH_20_SB(chspec0, ch0) {
		FOREACH_20_SB(chspec1, ch1) {
			if ((uint)ABS(ch0 - ch1) < CH_20MHZ_APART) {
				return TRUE;
			}
		}
	}

	return FALSE;
}

uint8
channel_bw_to_width(chanspec_t chspec)
{
	uint8 channel_width;

	if (CHSPEC_IS80(chspec))
		channel_width = VHT_OP_CHAN_WIDTH_80;
	else if (CHSPEC_IS160(chspec))
		channel_width = VHT_OP_CHAN_WIDTH_160;
	else if (CHSPEC_IS8080(chspec))
		channel_width = VHT_OP_CHAN_WIDTH_80_80;
	else
		channel_width = VHT_OP_CHAN_WIDTH_20_40;

	return channel_width;
}


uint
wf_chspec_first_20_sb(chanspec_t chspec)
{
	uint8 cc = wf_chspec_center_channel(chspec);
	/* This is to avoid infinite loop if return value is non-zero */
	if (chspec == INVCHANSPEC) {
		return 0;
	}
#if defined(BCMWIFI_BW320MHZ)
	if (CHSPEC_IS320(chspec)) {
		return LLLL_20_SB_320(cc);
	} else
#endif
#if defined(BCMWIFI_BW160MHZ)
	if (CHSPEC_IS160(chspec)) {
		return LLL_20_SB_160(cc);
	} else
#endif
	if (CHSPEC_IS80(chspec)) {
		return LL_20_SB(cc);
	} else if (CHSPEC_IS40(chspec)) {
		return LOWER_20_SB(cc);
	} else {
		return cc;
	}
}

chanspec_t
wf_create_chspec_sb(uint sb, uint center_channel, chanspec_bw_t bw,
	chanspec_band_t band)
{
	chanspec_t chspec;
	if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
		int chan_id = -1;
		if (sb > (WL_CHANSPEC_320_SB_MASK >> WL_CHANSPEC_320_SB_SHIFT)) {
			return INVCHANSPEC;
		}
		chan_id = channel_6g_320mhz_to_id(center_channel);
		if (chan_id == -1) {
			return INVCHANSPEC;
		}
		chspec = chan_id | band | bw | ((uint)sb << WL_CHANSPEC_320_SB_SHIFT);
	} else {
		if (sb > (WL_CHANSPEC_CTL_SB_MASK >> WL_CHANSPEC_CTL_SB_SHIFT)) {
			return INVCHANSPEC;
		}
		chspec = center_channel | band | bw | ((uint)sb << WL_CHANSPEC_CTL_SB_SHIFT);
	}
	return wf_chspec_valid(chspec) ? chspec : INVCHANSPEC;
}

chanspec_t
wf_create_8080MHz_chspec_sb(uint sb, uint chan0, uint chan1, chanspec_band_t band)
{
	int chan0_id, chan1_id, seg0, seg1;
	chanspec_t chspec;

	if (sb > (WL_CHANSPEC_CTL_SB_UUU >> WL_CHANSPEC_CTL_SB_SHIFT)) {
		return INVCHANSPEC;
	}
	/* From here on sb is not an index, but value for SB field */
	sb <<= WL_CHANSPEC_CTL_SB_SHIFT;

	/* frequency segments need to be non-contiguous, so the channel
	 * separation needs to be greater than 80MHz
	 */
	if ((uint)ABS((int)(chan0 - chan1)) <= CH_80MHZ_APART) {
		return INVCHANSPEC;
	}

	if (band == WL_CHANSPEC_BAND_5G) {
		chan0_id = channel_80mhz_to_id(chan0);
		chan1_id = channel_80mhz_to_id(chan1);
	} else if (band == WL_CHANSPEC_BAND_6G) {
		chan0_id = channel_6g_80mhz_to_id(chan0);
		chan1_id = channel_6g_80mhz_to_id(chan1);
	} else {
		return INVCHANSPEC;
	}

	/* make sure the channel numbers were valid */
	if ((chan0_id == -1) || (chan1_id == -1)) {
		return INVCHANSPEC;
	}
	/* Optionally swapping channel IDs to make sure that control subchannel
	 * is in chan0
	 */
	if (sb < WL_CHANSPEC_CTL_SB_ULL) {
		seg0 = chan0_id;
		seg1 = chan1_id;
	} else {
		seg0 = chan1_id;
		seg1 = chan0_id;
		sb -= WL_CHANSPEC_CTL_SB_ULL;
	}
	chspec = ((seg0 << WL_CHANSPEC_CHAN0_SHIFT) |
	         (seg1 << WL_CHANSPEC_CHAN1_SHIFT) |
	         sb | WL_CHANSPEC_BW_8080 | band);
	return wf_chspec_valid(chspec) ? chspec : INVCHANSPEC;
}

/**
 * Return the chanspec with the given center channel
 *
 * This function returns the channel spec with the given center channel number.
 * For 20MHz channels this is just the channel number. For 40MHz or wider channels
 * it is the primary 20MHz channel specified by the chanspec.
 *
 * @param	channel	input channel
 * @param	is_6G	indicatation of 6G channel
 *
 * @return Returns the chanspec including center channel and channel width
 */
chanspec_t
wf_create_chspec_with_center_channel(uint16 channel, bool is_6G)
{
	chanspec_t chspec;

	if (is_6G) {
		if (channel < WF_MAX_CHAN_NUM) {
			if ((channel & WF_CHAN_BITMASK_6G_320MHZ) == WF_CHAN_BITMASK_6G_320MHZ) {
				int chan_id = channel_6g_320mhz_to_id(channel);
				if (chan_id == -1) {
					return INVCHANSPEC;
				}
				chspec = (chan_id << WL_CHANSPEC_320_CHAN_SHIFT) |
					(0 << WL_CHANSPEC_320_SB_SHIFT) |
					WL_CHANSPEC_BW_320 | WL_CHANSPEC_BAND_6G;
			} else if ((channel & WF_CHAN_BITMASK_6G_160MHZ) ==
					WF_CHAN_BITMASK_6G_160MHZ) {
				chspec = CH160MHZ_CHSPEC_6G(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else if ((channel & WF_CHAN_BITMASK_6G_80MHZ) ==
					WF_CHAN_BITMASK_6G_80MHZ) {
				chspec = CH80MHZ_CHSPEC_6G(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else if ((channel & WF_CHAN_BITMASK_6G_40MHZ) ==
					WF_CHAN_BITMASK_6G_40MHZ) {
				chspec = CH40MHZ_CHSPEC_6G(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else {
				/* 6GHz 20MHz */
				chspec = CH20MHZ_CHSPEC_6G(channel);
			}
		} else {
			return INVCHANSPEC;

		}
	} else {
		if (channel < WF_MAX_CHAN_NUM) {
			if (channel < WF_MAX_2G_CHAN_NUM) {
				chspec = CH20MHZ_CHSPEC(channel);
			} else if ((channel & WF_CHAN_BITMASK_5G_40MHZ) ==
					WF_CHAN_BITMASK_5G_40MHZ) {
				chspec = CH40MHZ_CHSPEC(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else if ((channel & WF_CHAN_BITMASK_5G_80MHZ) ==
					WF_CHAN_BITMASK_5G_80MHZ) {
				chspec = CH80MHZ_CHSPEC(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else if ((channel & WF_CHAN_BITMASK_5G_160MHZ) ==
					WF_CHAN_BITMASK_5G_160MHZ) {
				chspec = CH160MHZ_CHSPEC(channel, WL_CHANSPEC_CTL_SB_NONE);
			} else {
				/* 5GHz 20MHz */
				chspec = CH20MHZ_CHSPEC(channel);
			}
		} else {
			return INVCHANSPEC;
		}
	}

	return chspec;
}

/* For 6GHz, use a formula to calculate the valid 40/80/160/320 center
 * channel from the primary channel. Caller needs to validate the
 * returned center channel.
 */
static uint
wf_6g_get_center_chan_from_primary(uint primary_channel, chanspec_bw_t bw,
	bool overlapped320)
{
	uint ch_per_block = 0;
	uint mask;
	uint base, center = INVCHANNEL;
	wf_6g_320m_chan_range_t const *range;
	uint i, size;
	uint8 bw_pos = WL_CHSPEC_BW(bw);

	if (bw_pos < ARRAYSIZE(ch_per_blk_map)) {
		ch_per_block = ch_per_blk_map[bw_pos];
	}

	if (WFC_BW_EQ(bw, WL_CHANSPEC_BW_320)) {
		if (primary_channel >= CH_MIN_6G_320M_START_CHAN ||
			primary_channel <= CH_MAX_6G_320M_END_CHAN) {
			if (overlapped320) {
				range = wf_6g_320m_ch_ol_set;
				size = ARRAYSIZE(wf_6g_320m_ch_ol_set);
			} else {
				range = wf_6g_320m_ch_set;
				size = ARRAYSIZE(wf_6g_320m_ch_set);
			}
			for (i = 0; i < size; i++) {
				if ((primary_channel >= range[i].start) &&
					(primary_channel <= range[i].end)) {
					center = range[i].center;
				}
			}
		}
	} else if (ch_per_block) {
		/* calculate the base of the block of channel numbers
		 * covered by the given bw
		 */
		mask = ~(ch_per_block - 1u);
		base = 1u + ((primary_channel - 1u) & mask);
		/* calculate the center channel from the base channel */
		center = base + center_chan_to_edge(bw);
	}
	return center;
}

uint8
wf_chspec_get_primary_sb(chanspec_t chspec)
{
	uint8 pri_sb;
	if (CHSPEC_IS320(chspec)) {
		pri_sb = CHSPEC_320_SB(chspec) >> WL_CHANSPEC_320_SB_SHIFT;
	} else {
		pri_sb = CHSPEC_CTL_SB(chspec) >> WL_CHANSPEC_CTL_SB_SHIFT;
	}
	return pri_sb;
}

/*
 * Returns the lower and uppper 20MHz chanel of the given chanspec.
 * separation is the next channel number from pervious.
 */
bool
wf_chspec_get_20m_lower_upper_channel(chanspec_t chspec, uint* lower, uint* upper, uint *separation)
{
	bool ret = FALSE;
	uint center_chan;
	if (wf_chspec_valid(chspec) && lower && upper && separation) {

		center_chan = wf_chspec_center_channel(chspec);
		*lower = center_chan - center_chan_to_edge(CHSPEC_BW(chspec));
		*upper = center_chan + center_chan_to_edge(CHSPEC_BW(chspec));

		if (CHSPEC_IS2G(chspec)) {
			*separation = 1u;
		} else {
			*separation = CH_20MHZ_APART;
		}
		ret = TRUE;
	}

	return ret;
}