1 /* 2 * Copyright (c) 2008-2011 Atheros Communications Inc. 3 * Copyright (c) 2011 Neratec Solutions AG 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include "hw.h" 19 #include "hw-ops.h" 20 #include "ath9k.h" 21 #include "dfs.h" 22 #include "dfs_debug.h" 23 24 /* internal struct to pass radar data */ 25 struct ath_radar_data { 26 u8 pulse_bw_info; 27 u8 rssi; 28 u8 ext_rssi; 29 u8 pulse_length_ext; 30 u8 pulse_length_pri; 31 }; 32 33 /* convert pulse duration to usecs, considering clock mode */ 34 static u32 dur_to_usecs(struct ath_hw *ah, u32 dur) 35 { 36 const u32 AR93X_NSECS_PER_DUR = 800; 37 const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11); 38 u32 nsecs; 39 40 if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan)) 41 nsecs = dur * AR93X_NSECS_PER_DUR_FAST; 42 else 43 nsecs = dur * AR93X_NSECS_PER_DUR; 44 45 return (nsecs + 500) / 1000; 46 } 47 48 #define PRI_CH_RADAR_FOUND 0x01 49 #define EXT_CH_RADAR_FOUND 0x02 50 static bool 51 ath9k_postprocess_radar_event(struct ath_softc *sc, 52 struct ath_radar_data *ard, 53 struct pulse_event *pe) 54 { 55 u8 rssi; 56 u16 dur; 57 58 /* 59 * Only the last 2 bits of the BW info are relevant, they indicate 60 * which channel the radar was detected in. 61 */ 62 ard->pulse_bw_info &= 0x03; 63 64 switch (ard->pulse_bw_info) { 65 case PRI_CH_RADAR_FOUND: 66 /* radar in ctrl channel */ 67 dur = ard->pulse_length_pri; 68 DFS_STAT_INC(sc, pri_phy_errors); 69 /* 70 * cannot use ctrl channel RSSI 71 * if extension channel is stronger 72 */ 73 rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi; 74 break; 75 case EXT_CH_RADAR_FOUND: 76 /* radar in extension channel */ 77 dur = ard->pulse_length_ext; 78 DFS_STAT_INC(sc, ext_phy_errors); 79 /* 80 * cannot use extension channel RSSI 81 * if control channel is stronger 82 */ 83 rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->ext_rssi; 84 break; 85 case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND): 86 /* 87 * Conducted testing, when pulse is on DC, both pri and ext 88 * durations are reported to be same 89 * 90 * Radiated testing, when pulse is on DC, different pri and 91 * ext durations are reported, so take the larger of the two 92 */ 93 if (ard->pulse_length_ext >= ard->pulse_length_pri) 94 dur = ard->pulse_length_ext; 95 else 96 dur = ard->pulse_length_pri; 97 DFS_STAT_INC(sc, dc_phy_errors); 98 99 /* when both are present use stronger one */ 100 rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->rssi; 101 break; 102 default: 103 /* 104 * Bogus bandwidth info was received in descriptor, 105 * so ignore this PHY error 106 */ 107 DFS_STAT_INC(sc, bwinfo_discards); 108 return false; 109 } 110 111 if (rssi == 0) { 112 DFS_STAT_INC(sc, rssi_discards); 113 return false; 114 } 115 116 /* 117 * TODO: check chirping pulses 118 * checks for chirping are dependent on the DFS regulatory domain 119 * used, which is yet TBD 120 */ 121 122 /* convert duration to usecs */ 123 pe->width = dur_to_usecs(sc->sc_ah, dur); 124 pe->rssi = rssi; 125 126 DFS_STAT_INC(sc, pulses_detected); 127 return true; 128 } 129 #undef PRI_CH_RADAR_FOUND 130 #undef EXT_CH_RADAR_FOUND 131 132 /* 133 * DFS: check PHY-error for radar pulse and feed the detector 134 */ 135 void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data, 136 struct ath_rx_status *rs, u64 mactime) 137 { 138 struct ath_radar_data ard; 139 u16 datalen; 140 char *vdata_end; 141 struct pulse_event pe; 142 struct ath_hw *ah = sc->sc_ah; 143 struct ath_common *common = ath9k_hw_common(ah); 144 145 DFS_STAT_INC(sc, pulses_total); 146 if ((rs->rs_phyerr != ATH9K_PHYERR_RADAR) && 147 (rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT)) { 148 ath_dbg(common, DFS, 149 "Error: rs_phyer=0x%x not a radar error\n", 150 rs->rs_phyerr); 151 DFS_STAT_INC(sc, pulses_no_dfs); 152 return; 153 } 154 155 datalen = rs->rs_datalen; 156 if (datalen == 0) { 157 DFS_STAT_INC(sc, datalen_discards); 158 return; 159 } 160 161 ard.rssi = rs->rs_rssi_ctl[0]; 162 ard.ext_rssi = rs->rs_rssi_ext[0]; 163 164 /* 165 * hardware stores this as 8 bit signed value. 166 * we will cap it at 0 if it is a negative number 167 */ 168 if (ard.rssi & 0x80) 169 ard.rssi = 0; 170 if (ard.ext_rssi & 0x80) 171 ard.ext_rssi = 0; 172 173 vdata_end = (char *)data + datalen; 174 ard.pulse_bw_info = vdata_end[-1]; 175 ard.pulse_length_ext = vdata_end[-2]; 176 ard.pulse_length_pri = vdata_end[-3]; 177 pe.freq = ah->curchan->channel; 178 pe.ts = mactime; 179 if (ath9k_postprocess_radar_event(sc, &ard, &pe)) { 180 struct dfs_pattern_detector *pd = sc->dfs_detector; 181 static u64 last_ts; 182 ath_dbg(common, DFS, 183 "ath9k_dfs_process_phyerr: channel=%d, ts=%llu, " 184 "width=%d, rssi=%d, delta_ts=%llu\n", 185 pe.freq, pe.ts, pe.width, pe.rssi, pe.ts-last_ts); 186 last_ts = pe.ts; 187 DFS_STAT_INC(sc, pulses_processed); 188 if (pd != NULL && pd->add_pulse(pd, &pe)) { 189 DFS_STAT_INC(sc, radar_detected); 190 ieee80211_radar_detected(sc->hw); 191 } 192 } 193 } 194