| /* |
| * Copyright (c) 2010 Broadcom Corporation |
| * |
| * Permission to use, copy, modify, and/or distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| */ |
| #include <linux/ctype.h> |
| #include <linux/kernel.h> |
| #include <bcmdefs.h> |
| #include <bcmutils.h> |
| #include <bcmwifi.h> |
| |
| /* |
| * 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 lowre 20MHZ |
| * sideband depending on the chanspec selected |
| */ |
| u8 wf_chspec_ctlchan(chanspec_t chspec) |
| { |
| u8 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; |
| u8 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; |
| } |
| |
| /* |
| * 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; |
| } |