text: /*
   * 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) 1999-2013, Broadcom Corporation
   * 
   *      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.
   * 
   *      Notwithstanding the above, under no circumstances may you combine this
   * software in any way with any other Broadcom software provided under a license
   * other than the GPL, without Broadcom's express prior written consent.
   * $Id: bcmwifi_channels.c 309193 2012-01-19 00:03:57Z $
   */
  
  #include <bcm_cfg.h>
  #include <typedefs.h>
  #include <bcmutils.h>
  
  #ifdef BCMDRIVER
  #include <osl.h>
  #define strtoul(nptr, endptr, base) bcm_strtoul((nptr), (endptr), (base))
  #define tolower(c) (bcm_isupper((c)) ? ((c) + 'a' - 'A') : (c))
  #else
  #include <stdio.h>
  #include <stdlib.h>
  #include <ctype.h>
  #ifndef ASSERT
  #define ASSERT(exp)
  #endif
  #endif /* BCMDRIVER */
  
  #ifdef _bcmwifi_c_
  /* temporary for transitional compatibility */
  #include <bcmwifi.h>
  #else
  #include <bcmwifi_channels.h>
  #endif
  
  #if defined(WIN32) && (defined(BCMDLL) || defined(WLMDLL))
  #include <bcmstdlib.h> 	/* For wl/exe/GNUmakefile.brcm_wlu and GNUmakefile.wlm_dll */
  #endif
  
  #ifndef D11AC_IOTYPES
  
  /* Definitions for legacy Chanspec type */
  
  /* Chanspec ASCII representation:
   * <channel><band><bandwidth><ctl-sideband>
   *   digit   [AB]     [N]        [UL]
   *
   * <channel>: channel number of the 10MHz or 20MHz channel,
   *	or control sideband channel of 40MHz channel.
   * <band>: A for 5GHz, B for 2.4GHz
   * <bandwidth>: N for 10MHz, nothing for 20MHz or 40MHz
   *	(ctl-sideband spec implies 40MHz)
   * <ctl-sideband>: U for upper, L for lower
   *
   * <band> may be omitted on input, and will be assumed to be
   * 2.4GHz if channel number <= 14.
   *
   * Examples:
   *	8  ->  2.4GHz channel 8, 20MHz
   *	8b ->  2.4GHz channel 8, 20MHz
   *	8l ->  2.4GHz channel 8, 40MHz, lower ctl sideband
   *	8a ->  5GHz channel 8 (low 5 GHz band), 20MHz
   *	36 ->  5GHz channel 36, 20MHz
   *	36l -> 5GHz channel 36, 40MHz, lower ctl sideband
   *	40u -> 5GHz channel 40, 40MHz, upper ctl sideband
   *	180n -> channel 180, 10MHz
   */
  
  
  /* given a chanspec and a string buffer, format the chanspec as a
   * string, and return the original pointer a.
   * Min buffer length must be CHANSPEC_STR_LEN.
   * On error return NULL
   */
  char *
  wf_chspec_ntoa(chanspec_t chspec, char *buf)
  {
  	const char *band, *bw, *sb;
  	uint channel;
  
  	band = "";
  	bw = "";
  	sb = "";
  	channel = CHSPEC_CHANNEL(chspec);
  	/* check for non-default band spec */
  	if ((CHSPEC_IS2G(chspec) && channel > CH_MAX_2G_CHANNEL) ||
  	    (CHSPEC_IS5G(chspec) && channel <= CH_MAX_2G_CHANNEL))
  		band = (CHSPEC_IS2G(chspec)) ? "b" : "a";
  	if (CHSPEC_IS40(chspec)) {
  		if (CHSPEC_SB_UPPER(chspec)) {
  			sb = "u";
  			channel += CH_10MHZ_APART;
  		} else {
  			sb = "l";
  			channel -= CH_10MHZ_APART;
  		}
  	} else if (CHSPEC_IS10(chspec)) {
  		bw = "n";
  	}
  
  	/* Outputs a max of 6 chars including '\0'  */
  	snprintf(buf, 6, "%d%s%s%s", channel, band, bw, sb);
  	return (buf);
  }
  
  /* given a chanspec string, convert to a chanspec.
   * On error return 0
   */
  chanspec_t
  wf_chspec_aton(const char *a)
  {
  	char *endp = NULL;
  	uint channel, band, bw, ctl_sb;
  	char c;
  
  	channel = strtoul(a, &endp, 10);
  
  	/* check for no digits parsed */
  	if (endp == a)
  		return 0;
  
  	if (channel > MAXCHANNEL)
  		return 0;
  
  	band = ((channel <= CH_MAX_2G_CHANNEL) ? WL_CHANSPEC_BAND_2G : WL_CHANSPEC_BAND_5G);
  	bw = WL_CHANSPEC_BW_20;
  	ctl_sb = WL_CHANSPEC_CTL_SB_NONE;
  
  	a = endp;
  
  	c = tolower(a[0]);
  	if (c == '\0')
  		goto done;
  
  	/* parse the optional ['A' | 'B'] band spec */
  	if (c == 'a' || c == 'b') {
  		band = (c == 'a') ? WL_CHANSPEC_BAND_5G : WL_CHANSPEC_BAND_2G;
  		a++;
  		c = tolower(a[0]);
  		if (c == '\0')
  			goto done;
  	}
  
  	/* parse bandwidth 'N' (10MHz) or 40MHz ctl sideband ['L' | 'U'] */
  	if (c == 'n') {
  		bw = WL_CHANSPEC_BW_10;
  	} else if (c == 'l') {
  		bw = WL_CHANSPEC_BW_40;
  		ctl_sb = WL_CHANSPEC_CTL_SB_LOWER;
  		/* adjust channel to center of 40MHz band */
  		if (channel <= (MAXCHANNEL - CH_20MHZ_APART))
  			channel += CH_10MHZ_APART;
  		else
  			return 0;
  	} else if (c == 'u') {
  		bw = WL_CHANSPEC_BW_40;
  		ctl_sb = WL_CHANSPEC_CTL_SB_UPPER;
  		/* adjust channel to center of 40MHz band */
  		if (channel > CH_20MHZ_APART)
  			channel -= CH_10MHZ_APART;
  		else
  			return 0;
  	} else {
  		return 0;
  	}
  
  done:
  	return (channel | band | bw | ctl_sb);
  }
  
  /*
   * Verify the chanspec is using a legal set of parameters, i.e. that the
   * chanspec specified a band, bw, ctl_sb and channel and that the
   * combination could be legal given any set of circumstances.
   * RETURNS: TRUE is the chanspec is malformed, false if it looks good.
   */
  bool
  wf_chspec_malformed(chanspec_t chanspec)
  {
  	/* must be 2G or 5G band */
  	if (!CHSPEC_IS5G(chanspec) && !CHSPEC_IS2G(chanspec))
  		return TRUE;
  	/* must be 20 or 40 bandwidth */
  	if (!CHSPEC_IS40(chanspec) && !CHSPEC_IS20(chanspec))
  		return TRUE;
  
  	/* 20MHZ b/w must have no ctl sb, 40 must have a ctl sb */
  	if (CHSPEC_IS20(chanspec)) {
  		if (!CHSPEC_SB_NONE(chanspec))
  			return TRUE;
  	} else {
  		if (!CHSPEC_SB_UPPER(chanspec) && !CHSPEC_SB_LOWER(chanspec))
  		return TRUE;
  	}
  
  	return FALSE;
  }
  
  /*
   * This function returns the channel number that control traffic is being sent on, for legacy
   * channels this is just the channel number, for 40MHZ channels it is the upper or lower 20MHZ
   * sideband depending on the chanspec selected
   */
  uint8
  wf_chspec_ctlchan(chanspec_t chspec)
  {
  	uint8 ctl_chan;
  
  	/* Is there a sideband ? */
  	if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
  		return CHSPEC_CHANNEL(chspec);
  	} else {
  		/* we only support 40MHZ with sidebands */
  		ASSERT(CHSPEC_BW(chspec) == WL_CHANSPEC_BW_40);
  		/* chanspec channel holds the centre frequency, use that and the
  		 * side band information to reconstruct the control channel number
  		 */
  		if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
  			/* control chan is the upper 20 MHZ SB of the 40MHZ channel */
  			ctl_chan = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
  		} else {
  			ASSERT(CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_LOWER);
  			/* control chan is the lower 20 MHZ SB of the 40MHZ channel */
  			ctl_chan = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
  		}
  	}
  
  	return ctl_chan;
  }
  
  chanspec_t
  wf_chspec_ctlchspec(chanspec_t chspec)
  {
  	chanspec_t ctl_chspec = 0;
  	uint8 channel;
  
  	ASSERT(!wf_chspec_malformed(chspec));
  
  	/* Is there a sideband ? */
  	if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_NONE) {
  		return chspec;
  	} else {
  		if (CHSPEC_CTL_SB(chspec) == WL_CHANSPEC_CTL_SB_UPPER) {
  			channel = UPPER_20_SB(CHSPEC_CHANNEL(chspec));
  		} else {
  			channel = LOWER_20_SB(CHSPEC_CHANNEL(chspec));
  		}
  		ctl_chspec = channel | WL_CHANSPEC_BW_20 | WL_CHANSPEC_CTL_SB_NONE;
  		ctl_chspec |= CHSPEC_BAND(chspec);
  	}
  	return ctl_chspec;
  }
  
  #else /* D11AC_IOTYPES */
  
  /* Definitions for D11AC capable Chanspec type */
  
  /* Chanspec ASCII representation with 802.11ac capability:
   * [<band> 'g'] <channel> ['/'<bandwidth> [<ctl-sideband>]['/'<1st80channel>'-'<2nd80channel>]]
   *
   * <band>:
   *      (optional) 2, 3, 4, 5 for 2.4GHz, 3GHz, 4GHz, and 5GHz respectively.
   *      Default value is 2g if channel <= 14, otherwise 5g.
   * <channel>:
   *      channel number of the 5MHz, 10MHz, 20MHz channel,
   *      or primary channel of 40MHz, 80MHz, 160MHz, or 80+80MHz channel.
   * <bandwidth>:
   *      (optional) 5, 10, 20, 40, 80, 160, or 80+80. Default value is 20.
   * <primary-sideband>:
   *      (only for 2.4GHz band 40MHz) U for upper sideband primary, L for lower.
   *
   *      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/L disambiguates which 40MHz channel
   *      is being specified.
   *
   *      For 40MHz in the 5GHz band and all channel bandwidths greater than
   *      40MHz, the U/L specificaion is not allowed since the channels are
   *      non-overlapping and the primary sub-band is derived from its
   *      position in the wide bandwidth channel.
   *
   * <1st80Channel>:
   * <2nd80Channel>:
   *      Required for 80+80, otherwise not allowed.
   *      Specifies the center channel of the first and second 80MHz band.
   *
   * 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><ctl-sideband>
   *
   * <channel>:
   *	primary channel of 40MHz, channel <= 14 is 2GHz, otherwise 5GHz
   * <ctl-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[] =
  {
  	"5",
  	"10",
  	"20",
  	"40",
  	"80",
  	"160",
  	"80+80",
  	"na"
  };
  
  static const uint8 wf_chspec_bw_mhz[] =
  {5, 10, 20, 40, 80, 160, 160};
  
  #define WF_NUM_BW \
  	(sizeof(wf_chspec_bw_mhz)/sizeof(uint8))
  
  /* 40MHz channels in 5GHz band */
  static const uint8 wf_5g_40m_chans[] =
  {38, 46, 54, 62, 102, 110, 118, 126, 134, 142, 151, 159};
  #define WF_NUM_5G_40M_CHANS \
  	(sizeof(wf_5g_40m_chans)/sizeof(uint8))
  
  /* 80MHz channels in 5GHz band */
  static const uint8 wf_5g_80m_chans[] =
  {42, 58, 106, 122, 138, 155};
  #define WF_NUM_5G_80M_CHANS \
  	(sizeof(wf_5g_80m_chans)/sizeof(uint8))
  
  /* 160MHz channels in 5GHz band */
  static const uint8 wf_5g_160m_chans[] =
  {50, 114};
  #define WF_NUM_5G_160M_CHANS \
  	(sizeof(wf_5g_160m_chans)/sizeof(uint8))
  
  
  /* convert bandwidth from chanspec to MHz */
  static uint
  bw_chspec_to_mhz(chanspec_t chspec)
  {
  	uint bw;
  
  	bw = (chspec & WL_CHANSPEC_BW_MASK) >> WL_CHANSPEC_BW_SHIFT;
  	return (bw >= WF_NUM_BW ? 0 : wf_chspec_bw_mhz[bw]);
  }
  
  /* bw in MHz, return the channel count from the center channel to the
   * the channel at the edge of the band
   */
  static uint8
  center_chan_to_edge(uint bw)
  {
  	/* edge channels separated by BW - 10MHz on each side
  	 * delta from cf to edge is half of that,
  	 * MHz to channel num conversion is 5MHz/channel
  	 */
  	return (uint8)(((bw - 20) / 2) / 5);
  }
  
  /* return channel number of the low edge of the band
   * given the center channel and BW
   */
  static uint8
  channel_low_edge(uint center_ch, uint bw)
  {
  	return (uint8)(center_ch - center_chan_to_edge(bw));
  }
  
  /* return side band number given center channel and control channel
   * return -1 on error
   */
  static int
  channel_to_sb(uint center_ch, uint ctl_ch, uint bw)
  {
  	uint lowest = channel_low_edge(center_ch, bw);
  	uint sb;
  
  	if ((ctl_ch - lowest) % 4) {
  		/* bad ctl channel, not mult 4 */
  		return -1;
  	}
  
  	sb = ((ctl_ch - lowest) / 4);
  
  	/* sb must be a index to a 20MHz channel in range */
  	if (sb >= (bw / 20)) {
  		/* ctl_ch must have been too high for the center_ch */
  		return -1;
  	}
  
  	return sb;
  }
  
  /* return control channel given center channel and side band */
  static uint8
  channel_to_ctl_chan(uint center_ch, uint bw, uint sb)
  {
  	return (uint8)(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;
  }
  
  /* given a chanspec and a string buffer, format the chanspec as a
   * string, and return the original pointer a.
   * 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 ctl_chan;
  
  	if (wf_chspec_malformed(chspec))
  		return NULL;
  
  	band = "";
  
  	/* check for non-default band spec */
  	if ((CHSPEC_IS2G(chspec) && CHSPEC_CHANNEL(chspec) > CH_MAX_2G_CHANNEL) ||
  	    (CHSPEC_IS5G(chspec) && CHSPEC_CHANNEL(chspec) <= CH_MAX_2G_CHANNEL))
  		band = (CHSPEC_IS2G(chspec)) ? "2g" : "5g";
  
  	/* ctl channel */
  	ctl_chan = wf_chspec_ctlchan(chspec);
  
  	/* bandwidth and ctl sideband */
  	if (CHSPEC_IS20(chspec)) {
  		snprintf(buf, CHANSPEC_STR_LEN, "%s%d", band, ctl_chan);
  	} else if (!CHSPEC_IS8080(chspec)) {
  		const char *bw;
  		const char *sb = "";
  
  		bw = wf_chspec_bw_str[(chspec & WL_CHANSPEC_BW_MASK) >> WL_CHANSPEC_BW_SHIFT];
  
  #ifdef CHANSPEC_NEW_40MHZ_FORMAT
  		/* ctl 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, ctl_chan, bw, sb);
  #else
  		/* ctl sideband string instead of BW for 40MHz */
  		if (CHSPEC_IS40(chspec)) {
  			sb = CHSPEC_SB_UPPER(chspec) ? "u" : "l";
  			snprintf(buf, CHANSPEC_STR_LEN, "%s%d%s", band, ctl_chan, sb);
  		} else {
  			snprintf(buf, CHANSPEC_STR_LEN, "%s%d/%s", band, ctl_chan, bw);
  		}
  #endif /* CHANSPEC_NEW_40MHZ_FORMAT */
  
  	} else {
  		/* 80+80 */
  		uint chan1 = (chspec & WL_CHANSPEC_CHAN1_MASK) >> WL_CHANSPEC_CHAN1_SHIFT;
  		uint chan2 = (chspec & WL_CHANSPEC_CHAN2_MASK) >> WL_CHANSPEC_CHAN2_SHIFT;
  
  		/* convert to channel number */
  		chan1 = (chan1 < WF_NUM_5G_80M_CHANS) ? wf_5g_80m_chans[chan1] : 0;
  		chan2 = (chan2 < WF_NUM_5G_80M_CHANS) ? wf_5g_80m_chans[chan2] : 0;
  
  		/* Outputs a max of CHANSPEC_STR_LEN chars including '\0'  */
  		snprintf(buf, CHANSPEC_STR_LEN, "%d/80+80/%d-%d", ctl_chan, chan1, chan2);
  	}
  
  	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;
  }
  
  /* given a chanspec string, convert to a chanspec.
   * On error return 0
   */
  chanspec_t
  wf_chspec_aton(const char *a)
  {
  	chanspec_t chspec;
  	uint chspec_ch, chspec_band, bw, chspec_bw, chspec_sb;
  	uint num, ctl_ch;
  	uint ch1, ch2;
  	char c, sb_ul = '\0';
  	int i;
  
  	bw = 20;
  	chspec_sb = 0;
  	chspec_ch = ch1 = ch2 = 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" or "5" */
  		if (num == 2)
  			chspec_band = WL_CHANSPEC_BAND_2G;
  		else if (num == 5)
  			chspec_band = WL_CHANSPEC_BAND_5G;
  		else
  			return 0;
  
  		/* read the channel number */
  		if (!read_uint(&a, &ctl_ch))
  			return 0;
  
  		c = tolower((int)a[0]);
  	}
  	else {
  		/* first number is channel, use default for band */
  		ctl_ch = num;
  		chspec_band = ((ctl_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 {
  		return 0;
  	}
  
  	/* So far we have <band>g<chan>/<bw>
  	 * Can now be followed by u/l if bw = 40,
  	 * or '+80' if bw = 80, to make '80+80' bw.
  	 */
  
  	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 == '+') {
  		/* 80+80 */
  		static const char *plus80 = "80/";
  
  		/* must be looking at '+80/'
  		 * check and consume this string.
  		 */
  		chspec_bw = WL_CHANSPEC_BW_8080;
  
  		a ++; /* consume the char '+' */
  
  		/* consume the '80/' string */
  		for (i = 0; i < 3; i++) {
  			if (*a++ != *plus80++) {
  				return 0;
  			}
  		}
  
  		/* read primary 80MHz channel */
  		if (!read_uint(&a, &ch1))
  			return 0;
  
  		/* must followed by '-' */
  		if (a[0] != '-')
  			return 0;
  		a ++; /* consume the char */
  
  		/* read secondary 80MHz channel */
  		if (!read_uint(&a, &ch2))
  			return 0;
  	}
  
  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, ctl_ch, chspec_bw, sb_ul, ch1, ch2.
  	 * chspec_band and chspec_bw are chanspec values.
  	 * Need to convert ctl_ch, sb_ul, and ch1,ch2 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 sting parse.
  	 */
  	if (sb_ul != '\0') {
  		if (sb_ul == 'l') {
  			chspec_ch = UPPER_20_SB(ctl_ch);
  			chspec_sb = WL_CHANSPEC_CTL_SB_LLL;
  		} else if (sb_ul == 'u') {
  			chspec_ch = LOWER_20_SB(ctl_ch);
  			chspec_sb = WL_CHANSPEC_CTL_SB_LLU;
  		}
  	}
  	/* if the bw is 20, center and sideband are trivial */
  	else if (chspec_bw == WL_CHANSPEC_BW_20) {
  		chspec_ch = ctl_ch;
  		chspec_sb = 0;
  	}
  	/* if the bw is 40/80/160, not 80+80, a single method
  	 * can be used to to find the center and sideband
  	 */
  	else if (chspec_bw != WL_CHANSPEC_BW_8080) {
  		/* figure out ctl sideband based on ctl channel and bandwidth */
  		const uint8 *center_ch = NULL;
  		int num_ch = 0;
  		int sb = -1;
  
  		if (chspec_bw == WL_CHANSPEC_BW_40) {
  			center_ch = wf_5g_40m_chans;
  			num_ch = WF_NUM_5G_40M_CHANS;
  		} else if (chspec_bw == WL_CHANSPEC_BW_80) {
  			center_ch = wf_5g_80m_chans;
  			num_ch = WF_NUM_5G_80M_CHANS;
  		} else if (chspec_bw == WL_CHANSPEC_BW_160) {
  			center_ch = wf_5g_160m_chans;
  			num_ch = WF_NUM_5G_160M_CHANS;
  		} else {
  			return 0;
  		}
  
  		for (i = 0; i < num_ch; i ++) {
  			sb = channel_to_sb(center_ch[i], ctl_ch, bw);
  			if (sb >= 0) {
  				chspec_ch = center_ch[i];
  				chspec_sb = sb << WL_CHANSPEC_CTL_SB_SHIFT;
  				break;
  			}
  		}
  
  		/* check for no matching sb/center */
  		if (sb < 0) {
  			return 0;
  		}
  	}
  	/* Otherwise, bw is 80+80. Figure out channel pair and sb */
  	else {
  		int ch1_id = 0, ch2_id = 0;
  		int sb;
  
  		ch1_id = channel_80mhz_to_id(ch1);
  		ch2_id = channel_80mhz_to_id(ch2);
  
  		/* validate channels */
  		if (ch1 >= ch2 || ch1_id < 0 || ch2_id < 0)
  			return 0;
  
  		/* combined channel in chspec */
  		chspec_ch = (((uint16)ch1_id << WL_CHANSPEC_CHAN1_SHIFT) |
  			((uint16)ch2_id << WL_CHANSPEC_CHAN2_SHIFT));
  
  		/* figure out ctl sideband */
  
  		/* does the primary channel fit with the 1st 80MHz channel ? */
  		sb = channel_to_sb(ch1, ctl_ch, bw);
  		if (sb < 0) {
  			/* no, so does the primary channel fit with the 2nd 80MHz channel ? */
  			sb = channel_to_sb(ch2, ctl_ch, bw);
  			if (sb < 0) {
  				/* no match for ctl_ch to either 80MHz center channel */
  				return 0;
  			}
  			/* sb index is 0-3 for the low 80MHz channel, and 4-7 for
  			 * the high 80MHz channel. Add 4 to to shift to high set.
  			 */
  			sb += 4;
  		}
  
  		chspec_sb = sb << WL_CHANSPEC_CTL_SB_SHIFT;
  	}
  
  	chspec = (chspec_ch | chspec_band | chspec_bw | chspec_sb);
  
  	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, ctl_sb and channel and that the
   * combination could be legal given any set of circumstances.
   * RETURNS: TRUE is the chanspec is malformed, false if it looks good.
   */
  bool
  wf_chspec_malformed(chanspec_t chanspec)
  {
  	uint chspec_bw = CHSPEC_BW(chanspec);
  	uint chspec_ch = CHSPEC_CHANNEL(chanspec);
  
  	/* must be 2G or 5G band */
  	if (CHSPEC_IS2G(chanspec)) {
  		/* must be valid bandwidth */
  		if (chspec_bw != WL_CHANSPEC_BW_20 &&
  		    chspec_bw != WL_CHANSPEC_BW_40) {
  			return TRUE;
  		}
  	} else if (CHSPEC_IS5G(chanspec)) {
  		if (chspec_bw == WL_CHANSPEC_BW_8080) {
  			uint ch1_id, ch2_id;
  
  			/* channel number in 80+80 must be in range */
  			ch1_id = CHSPEC_CHAN1(chanspec);
  			ch2_id = CHSPEC_CHAN2(chanspec);
  			if (ch1_id >= WF_NUM_5G_80M_CHANS || ch2_id >= WF_NUM_5G_80M_CHANS)
  				return TRUE;
  
  			/* ch2 must be above ch1 for the chanspec */
  			if (ch2_id <= ch1_id)
  				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) {
  
  			if (chspec_ch > MAXCHANNEL) {
  				return TRUE;
  			}
  		} else {
  			/* invalid bandwidth */
  			return TRUE;
  		}
  	} else {
  		/* must be 2G or 5G band */
  		return TRUE;
  	}
  
  	/* side band needs to be consistent with bandwidth */
  	if (chspec_bw == WL_CHANSPEC_BW_20) {
  		if (CHSPEC_CTL_SB(chanspec) != WL_CHANSPEC_CTL_SB_LLL)
  			return TRUE;
  	} else if (chspec_bw == WL_CHANSPEC_BW_40) {
  		if (CHSPEC_CTL_SB(chanspec) > WL_CHANSPEC_CTL_SB_LLU)
  			return TRUE;
  	} else if (chspec_bw == WL_CHANSPEC_BW_80) {
  		if (CHSPEC_CTL_SB(chanspec) > WL_CHANSPEC_CTL_SB_LUU)
  			return TRUE;
  	}
  
  	return FALSE;
  }
  
  /*
   * Verify the chanspec specifies a valid channel according to 802.11.
   * RETURNS: TRUE if the chanspec is a valid 802.11 channel
   */
  bool
  wf_chspec_valid(chanspec_t chanspec)
  {
  	uint chspec_bw = CHSPEC_BW(chanspec);
  	uint chspec_ch = CHSPEC_CHANNEL(chanspec);
  
  	if (wf_chspec_malformed(chanspec))
  		return FALSE;
  
  	if (CHSPEC_IS2G(chanspec)) {
  		/* must be valid bandwidth and channel range */
  		if (chspec_bw == WL_CHANSPEC_BW_20) {
  			if (chspec_ch >= 1 && chspec_ch <= 14)
  				return TRUE;
  		} else if (chspec_bw == WL_CHANSPEC_BW_40) {
  			if (chspec_ch >= 3 && chspec_ch <= 11)
  				return TRUE;
  		}
  	} else if (CHSPEC_IS5G(chanspec)) {
  		if (chspec_bw == WL_CHANSPEC_BW_8080) {
  			uint16 ch1, ch2;
  
  			ch1 = wf_5g_80m_chans[CHSPEC_CHAN1(chanspec)];
  			ch2 = wf_5g_80m_chans[CHSPEC_CHAN2(chanspec)];
  
  			/* the two channels must be separated by more than 80MHz by VHT req,
  			 * and ch2 above ch1 for the chanspec
  			 */
  			if (ch2 > ch1 + CH_80MHZ_APART)
  				return TRUE;
  		} else {
  			const uint8 *center_ch;
  			uint num_ch, i;
  
  			if (chspec_bw == WL_CHANSPEC_BW_20 || chspec_bw == WL_CHANSPEC_BW_40) {
  				center_ch = wf_5g_40m_chans;
  				num_ch = WF_NUM_5G_40M_CHANS;
  			} else if (chspec_bw == WL_CHANSPEC_BW_80) {
  				center_ch = wf_5g_80m_chans;
  				num_ch = WF_NUM_5G_80M_CHANS;
  			} else if (chspec_bw == WL_CHANSPEC_BW_160) {
  				center_ch = wf_5g_160m_chans;
  				num_ch = WF_NUM_5G_160M_CHANS;
  			} else {
  				/* invalid bandwidth */
  				return FALSE;
  			}
  
  			/* check for a valid center channel */
  			if (chspec_bw == WL_CHANSPEC_BW_20) {
  				/* 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 (chspec_ch == (uint)LOWER_20_SB(center_ch[i]) ||
  					    chspec_ch == (uint)UPPER_20_SB(center_ch[i]))
  						break; /* match found */
  				}
  
  				if (i == num_ch) {
  					/* check for channel 165 which is not the side band
  					 * of 40MHz 5G channel
  					 */
  					if (chspec_ch == 165)
  						i = 0;
  
  					/* check for legacy JP channels on failure */
  					if (chspec_ch == 34 || chspec_ch == 38 ||
  					    chspec_ch == 42 || chspec_ch == 46)
  						i = 0;
  				}
  			} else {
  				/* check the chanspec channel to each legal channel */
  				for (i = 0; i < num_ch; i ++) {
  					if (chspec_ch == center_ch[i])
  						break; /* match found */
  				}
  			}
  
  			if (i < num_ch) {
  				/* match found */
  				return TRUE;
  			}
  		}
  	}
  
  	return FALSE;
  }
  
  /*
   * This function returns the channel number that control traffic is being sent on, for 20MHz
   * channels this is just the channel number, for 40MHZ, 80MHz, 160MHz channels it is the 20MHZ
   * sideband depending on the chanspec selected
   */
  uint8
  wf_chspec_ctlchan(chanspec_t chspec)
  {
  	uint center_chan;
  	uint bw_mhz;
  	uint sb;
  
  	ASSERT(!wf_chspec_malformed(chspec));
  
  	/* Is there a sideband ? */
  	if (CHSPEC_IS20(chspec)) {
  		return CHSPEC_CHANNEL(chspec);
  	} else {
  		sb = CHSPEC_CTL_SB(chspec) >> WL_CHANSPEC_CTL_SB_SHIFT;
  
  		if (CHSPEC_IS8080(chspec)) {
  			bw_mhz = 80;
  
  			if (sb < 4) {
  				center_chan = CHSPEC_CHAN1(chspec);
  			}
  			else {
  				center_chan = CHSPEC_CHAN2(chspec);
  				sb -= 4;
  			}
  
  			/* convert from channel index to channel number */
  			center_chan = wf_5g_80m_chans[center_chan];
  		}
  		else {
  			bw_mhz = bw_chspec_to_mhz(chspec);
  			center_chan = CHSPEC_CHANNEL(chspec) >> WL_CHANSPEC_CHAN_SHIFT;
  		}
  
  		return (channel_to_ctl_chan(center_chan, bw_mhz, sb));
  	}
  }
  
  /*
   * This function returns the chanspec of the control channel of a given chanspec
   */
  chanspec_t
  wf_chspec_ctlchspec(chanspec_t chspec)
  {
  	chanspec_t ctl_chspec = chspec;
  	uint8 ctl_chan;
  
  	ASSERT(!wf_chspec_malformed(chspec));
  
  	/* Is there a sideband ? */
  	if (!CHSPEC_IS20(chspec)) {
  		ctl_chan = wf_chspec_ctlchan(chspec);
  		ctl_chspec = ctl_chan | WL_CHANSPEC_BW_20;
  		ctl_chspec |= CHSPEC_BAND(chspec);
  	}
  	return ctl_chspec;
  }
  
  /* return chanspec given control channel and bandwidth
   * return 0 on error
   */
  uint16
  wf_channel2chspec(uint ctl_ch, uint bw)
  {
  	uint16 chspec;
  	const uint8 *center_ch = NULL;
  	int num_ch = 0;
  	int sb = -1;
  	int i = 0;
  
  	chspec = ((ctl_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;
  		bw = 40;
  	} else if (bw == WL_CHANSPEC_BW_80) {
  		center_ch = wf_5g_80m_chans;
  		num_ch = WF_NUM_5G_80M_CHANS;
  		bw = 80;
  	} else if (bw == WL_CHANSPEC_BW_160) {
  		center_ch = wf_5g_160m_chans;
  		num_ch = WF_NUM_5G_160M_CHANS;
  		bw = 160;
  	} else if (bw == WL_CHANSPEC_BW_20) {
  		chspec |= ctl_ch;
  		return chspec;
  	} else {
  		return 0;
  	}
  
  	for (i = 0; i < num_ch; i ++) {
  		sb = channel_to_sb(center_ch[i], ctl_ch, 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;
  }
  
  #endif /* D11AC_IOTYPES */
  
  /*
   * This function returns the chanspec for the primary 40MHz of an 80MHz channel.
   * The control sideband specifies the same 20MHz channel that the 80MHz channel is using
   * as the primary 20MHz channel.
   */
  extern chanspec_t wf_chspec_primary40_chspec(chanspec_t chspec)
  {
  	chanspec_t chspec40 = chspec;
  	uint center_chan;
  	uint sb;
  
  	ASSERT(!wf_chspec_malformed(chspec));
  
  	if (CHSPEC_IS80(chspec)) {
  		center_chan = CHSPEC_CHANNEL(chspec);
  		sb = CHSPEC_CTL_SB(chspec);
  
  		if (sb == WL_CHANSPEC_CTL_SB_UL) {
  			/* Primary 40MHz is on upper side */
  			sb = WL_CHANSPEC_CTL_SB_L;
  			center_chan += CH_20MHZ_APART;
  		} else if (sb == WL_CHANSPEC_CTL_SB_UU) {
  			/* Primary 40MHz is on upper side */
  			sb = WL_CHANSPEC_CTL_SB_U;
  			center_chan += CH_20MHZ_APART;
  		} else {
  			/* Primary 40MHz is on lower side */
  			/* sideband bits are the same for LL/LU and L/U */
  			center_chan -= CH_20MHZ_APART;
  		}
  
  		/* Create primary 40MHz chanspec */
  		chspec40 = (WL_CHANSPEC_BAND_5G | WL_CHANSPEC_BW_40 |
  		            sb | center_chan);
  	}
  
  	return chspec40;
  }
  
  /*
   * Return the channel number for a given frequency and base frequency.
   * The returned channel number is relative to the given base frequency.
   * If the given base frequency is zero, a base frequency of 5 GHz is assumed for
   * frequencies from 5 - 6 GHz, and 2.407 GHz is assumed for 2.4 - 2.5 GHz.
   *
   * Frequency is specified in MHz.
   * The base frequency is specified as (start_factor * 500 kHz).
   * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_5_G are defined for
   * 2.4 GHz and 5 GHz bands.
   *
   * The returned channel will be in the range [1, 14] in the 2.4 GHz band
   * and [0, 200] otherwise.
   * -1 is returned if the start_factor is WF_CHAN_FACTOR_2_4_G and the
   * frequency is not a 2.4 GHz channel, or if the frequency is not and even
   * multiple of 5 MHz from the base frequency to the base plus 1 GHz.
   *
   * Reference 802.11 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
   */
  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 <= 6000)
  			start_factor = WF_CHAN_FACTOR_5_G;
  	}
  
  	if (freq == 2484 && start_factor == WF_CHAN_FACTOR_2_4_G)
  		return 14;
  
  	base = start_factor / 2;
  
  	/* check that the frequency is in 1GHz range of the base */
  	if ((freq < base) || (freq > base + 1000))
  		return -1;
  
  	offset = freq - base;
  	ch = offset / 5;
  
  	/* check that frequency is a 5MHz multiple from the base */
  	if (offset != (ch * 5))
  		return -1;
  
  	/* restricted channel range check for 2.4G */
  	if (start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 13))
  		return -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 and [0, 200] otherwise.
   * The base frequency is specified as (start_factor * 500 kHz).
   * Constants WF_CHAN_FACTOR_2_4_G, WF_CHAN_FACTOR_4_G, and WF_CHAN_FACTOR_5_G
   * are defined for 2.4 GHz, 4 GHz, and 5 GHz bands.
   * The channel range of [1, 14] is only checked for a start_factor of
   * WF_CHAN_FACTOR_2_4_G (4814 = 2407 * 2).
   * 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 REVma, section 17.3.8.3, and 802.11B section 18.4.6.2
   */
  int
  wf_channel2mhz(uint ch, uint start_factor)
  {
  	int freq;
  
  	if ((start_factor == WF_CHAN_FACTOR_2_4_G && (ch < 1 || ch > 14)) ||
  	    (ch > 200))
  		freq = -1;
  	else if ((start_factor == WF_CHAN_FACTOR_2_4_G) && (ch == 14))
  		freq = 2484;
  	else
  		freq = ch * 5 + start_factor / 2;
  
  	return freq;
  }
  
  /* These chan_info[] & lookup routines replicate those from wlc_phy.c because of BMAC split */
  static const struct chan_info {
  	uint16	chan;	/* channel number */
  	uint16	freq;	/* in MHz */
  } chan_info[] = {
  	/* 11b/11g */
  /* 0 */		{1,	2412},
  /* 1 */		{2,	2417},
  /* 2 */		{3,	2422},
  /* 3 */		{4,	2427},
  /* 4 */		{5,	2432},
  /* 5 */		{6,	2437},
  /* 6 */		{7,	2442},
  /* 7 */		{8,	2447},
  /* 8 */		{9,	2452},
  /* 9 */		{10,	2457},
  /* 10 */	{11,	2462},
  /* 11 */	{12,	2467},
  /* 12 */	{13,	2472},
  /* 13 */	{14,	2484},
  
  #ifdef BAND5G
  /* 11a japan high */
  /* 14 */	{34,	5170},
  /* 15 */	{38,	5190},
  /* 16 */	{42,	5210},
  /* 17 */	{46,	5230},
  
  /* 11a usa low */
  /* 18 */	{36,	5180},
  /* 19 */	{40,	5200},
  /* 20 */	{44,	5220},
  /* 21 */	{48,	5240},
  /* 22 */	{52,	5260},
  /* 23 */	{56,	5280},
  /* 24 */	{60,	5300},
  /* 25 */	{64,	5320},
  
  /* 11a Europe */
  /* 26 */	{100,	5500},
  /* 27 */	{104,	5520},
  /* 28 */	{108,	5540},
  /* 29 */	{112,	5560},
  /* 30 */	{116,	5580},
  /* 31 */	{120,	5600},
  /* 32 */	{124,	5620},
  /* 33 */	{128,	5640},
  /* 34 */	{132,	5660},
  /* 35 */	{136,	5680},
  /* 36 */	{140,	5700},
  
  /* 11a usa high, ref5 only */
  /* 37 */	{149,	5745},
  /* 38 */	{153,	5765},
  /* 39 */	{157,	5785},
  /* 40 */	{161,	5805},
  /* 41 */	{165,	5825},
  
  /* 11a japan */
  /* 42 */	{184,	4920},
  /* 43 */	{188,	4940},
  /* 44 */	{192,	4960},
  /* 45 */	{196,	4980},
  /* 46 */	{200,	5000},
  /* 47 */	{204,	5020},
  /* 48 */	{208,	5040},
  /* 49 */	{212,	5060},
  /* 50 */	{216,	5080}
  #endif /* BAND5G */
  };
  
  /*
   * Converts channel frequency to channel number.
   * Returns 0 if the frequency does not match any channel definition.
   */
  uint
  wf_freq2channel(uint freq)
  {
  	uint i;
  
  	for (i = 0; i < ARRAYSIZE(chan_info); i++) {
  		if (chan_info[i].freq == freq)
  			return (chan_info[i].chan);
  	}
  	return (0);
  }
  
  /*
   * Converts channel number to channel frequency.
   * Returns 0 if the channel is out of range.
   * Also used by some code in wlc_iw.c
   */
  uint
  wf_channel2freq(uint channel)
  {
  	uint i;
  
  	for (i = 0; i < ARRAYSIZE(chan_info); i++)
  		if (chan_info[i].chan == channel)
  			return (chan_info[i].freq);
  	return (0);
  }
  