/*
* Convert MHz frequency to IEEE channel number.
*/
int
ieee80211_mhz2ieee(u_int freq, u_int flags)
{
#define IS_FREQ_IN_PSB(_freq) ((_freq) > 4940 && (_freq) < 4990)
if (flags & IEEE80211_CHAN_GSM)
return mapgsm(freq, flags);
if (flags & IEEE80211_CHAN_2GHZ) { /* 2GHz band */
if (freq == 2484)
return 14;
if (freq < 2484)
return ((int) freq - 2407) / 5;
else
return 15 + ((freq - 2512) / 20);
} else if (flags & IEEE80211_CHAN_5GHZ) { /* 5Ghz band */
if (freq <= 5000) {
/* XXX check regdomain? */
if (IS_FREQ_IN_PSB(freq))
return mappsb(freq, flags);
return (freq - 4000) / 5;
} else
return (freq - 5000) / 5;
} else { /* either, guess */
if (freq == 2484)
return 14;
if (freq < 2484) {
if (907 <= freq && freq <= 922)
return mapgsm(freq, flags);
return ((int) freq - 2407) / 5;
}
if (freq < 5000) {
if (IS_FREQ_IN_PSB(freq))
return mappsb(freq, flags);
else if (freq > 4900)
return (freq - 4000) / 5;
else
return 15 + ((freq - 2512) / 20);
}
return (freq - 5000) / 5;
}
#undef IS_FREQ_IN_PSB
}
/*
* Convert MHz frequency to IEEE channel number.
*/
static u_int
ieee80211_mhz2ieee(u_int isrfreq, u_int isrflags)
{
if ((isrflags & IEEE80211_CHAN_GSM) || (907 <= isrfreq && isrfreq <= 922))
return mapgsm(isrfreq, isrflags);
if (isrfreq == 2484)
return 14;
if (isrfreq < 2484)
return (isrfreq - 2407) / 5;
if (isrfreq < 5000) {
if (isrflags & (IEEE80211_CHAN_HALF|IEEE80211_CHAN_QUARTER))
return mappsb(isrfreq, isrflags);
else if (isrfreq > 4900)
return (isrfreq - 4000) / 5;
else
return 15 + ((isrfreq - 2512) / 20);
}
return (isrfreq - 5000) / 5;
}
