diff options
Diffstat (limited to 'drivers/staging/brcm80211/util/bcmwifi.c')
| -rw-r--r-- | drivers/staging/brcm80211/util/bcmwifi.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/staging/brcm80211/util/bcmwifi.c b/drivers/staging/brcm80211/util/bcmwifi.c new file mode 100644 index 0000000..1bb6c78 --- /dev/null +++ b/drivers/staging/brcm80211/util/bcmwifi.c @@ -0,0 +1,189 @@ +/* + * 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; +} |
