diff options
Diffstat (limited to 'drivers/net/wireless/brcm80211/brcmutil/wifi.c')
| -rw-r--r-- | drivers/net/wireless/brcm80211/brcmutil/wifi.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/net/wireless/brcm80211/brcmutil/wifi.c b/drivers/net/wireless/brcm80211/brcmutil/wifi.c new file mode 100644 index 00000000000..509e25c9c86 --- /dev/null +++ b/drivers/net/wireless/brcm80211/brcmutil/wifi.c @@ -0,0 +1,136 @@ +/* + * 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 <brcmu_wifi.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 brcmu_chspec_malformed(u16 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; +} +EXPORT_SYMBOL(brcmu_chspec_malformed); + +/* + * 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. + */ +u8 brcmu_chspec_ctlchan(u16 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. 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 + /* + * control chan is the lower 20 MHZ SB of the + * 40MHZ channel + */ + ctl_chan = lower_20_sb(CHSPEC_CHANNEL(chspec)); + } + + return ctl_chan; +} +EXPORT_SYMBOL(brcmu_chspec_ctlchan); + +/* + * 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 brcmu_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; +} +EXPORT_SYMBOL(brcmu_mhz2channel); |