From 9ee677c2276bfcbcf68042ec2718a504af0c5fd7 Mon Sep 17 00:00:00 2001 From: David Kilroy Date: Tue, 23 Dec 2008 14:03:38 +0000 Subject: wireless: Add channel/frequency conversions to ieee80211.h Added mappings for FHSS, DSSS and OFDM channels - with macros to point HR DSSS and ERP to the DSSS mappings. Currently just static inline functions. Use the new functions in the older fullmac drivers. This eliminates a number of const static buffers and removes a couple of range checks that are now redundant. Signed-off-by: David Kilroy Acked-by: Arnaldo Carvalho de Melo Acked-by: Richard Farina Acked-by: Jeroen Vreeken Signed-off-by: John W. Linville --- include/linux/ieee80211.h | 116 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) (limited to 'include/linux/ieee80211.h') diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index c4e6ca1a630..cade2556af0 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1185,4 +1185,120 @@ static inline u8 *ieee80211_get_DA(struct ieee80211_hdr *hdr) return hdr->addr1; } +/** + * ieee80211_fhss_chan_to_freq - get channel frequency + * @channel: the FHSS channel + * + * Convert IEEE802.11 FHSS channel to frequency (MHz) + * Ref IEEE 802.11-2007 section 14.6 + */ +static inline int ieee80211_fhss_chan_to_freq(int channel) +{ + if ((channel > 1) && (channel < 96)) + return channel + 2400; + else + return -1; +} + +/** + * ieee80211_freq_to_fhss_chan - get channel + * @freq: the channels frequency + * + * Convert frequency (MHz) to IEEE802.11 FHSS channel + * Ref IEEE 802.11-2007 section 14.6 + */ +static inline int ieee80211_freq_to_fhss_chan(int freq) +{ + if ((freq > 2401) && (freq < 2496)) + return freq - 2400; + else + return -1; +} + +/** + * ieee80211_dsss_chan_to_freq - get channel center frequency + * @channel: the DSSS channel + * + * Convert IEEE802.11 DSSS channel to the center frequency (MHz). + * Ref IEEE 802.11-2007 section 15.6 + */ +static inline int ieee80211_dsss_chan_to_freq(int channel) +{ + if ((channel > 0) && (channel < 14)) + return 2407 + (channel * 5); + else if (channel == 14) + return 2484; + else + return -1; +} + +/** + * ieee80211_freq_to_dsss_chan - get channel + * @freq: the frequency + * + * Convert frequency (MHz) to IEEE802.11 DSSS channel + * Ref IEEE 802.11-2007 section 15.6 + * + * This routine selects the channel with the closest center frequency. + */ +static inline int ieee80211_freq_to_dsss_chan(int freq) +{ + if ((freq >= 2410) && (freq < 2475)) + return (freq - 2405) / 5; + else if ((freq >= 2482) && (freq < 2487)) + return 14; + else + return -1; +} + +/* Convert IEEE802.11 HR DSSS channel to frequency (MHz) and back + * Ref IEEE 802.11-2007 section 18.4.6.2 + * + * The channels and frequencies are the same as those defined for DSSS + */ +#define ieee80211_hr_chan_to_freq(chan) ieee80211_dsss_chan_to_freq(chan) +#define ieee80211_freq_to_hr_chan(freq) ieee80211_freq_to_dsss_chan(freq) + +/* Convert IEEE802.11 ERP channel to frequency (MHz) and back + * Ref IEEE 802.11-2007 section 19.4.2 + */ +#define ieee80211_erp_chan_to_freq(chan) ieee80211_hr_chan_to_freq(chan) +#define ieee80211_freq_to_erp_chan(freq) ieee80211_freq_to_hr_chan(freq) + +/** + * ieee80211_ofdm_chan_to_freq - get channel center frequency + * @s_freq: starting frequency == (dotChannelStartingFactor/2) MHz + * @channel: the OFDM channel + * + * Convert IEEE802.11 OFDM channel to center frequency (MHz) + * Ref IEEE 802.11-2007 section 17.3.8.3.2 + */ +static inline int ieee80211_ofdm_chan_to_freq(int s_freq, int channel) +{ + if ((channel > 0) && (channel <= 200) && + (s_freq >= 4000)) + return s_freq + (channel * 5); + else + return -1; +} + +/** + * ieee80211_freq_to_ofdm_channel - get channel + * @s_freq: starting frequency == (dotChannelStartingFactor/2) MHz + * @freq: the frequency + * + * Convert frequency (MHz) to IEEE802.11 OFDM channel + * Ref IEEE 802.11-2007 section 17.3.8.3.2 + * + * This routine selects the channel with the closest center frequency. + */ +static inline int ieee80211_freq_to_ofdm_chan(int s_freq, int freq) +{ + if ((freq > (s_freq + 2)) && (freq <= (s_freq + 1202)) && + (s_freq >= 4000)) + return (freq + 2 - s_freq) / 5; + else + return -1; +} + #endif /* LINUX_IEEE80211_H */ -- cgit v1.2.3