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 /* 25 * TODO: move into or synchronize this with generic header 26 * as soon as IF is defined 27 */ 28 struct dfs_radar_pulse { 29 u16 freq; 30 u64 ts; 31 u32 width; 32 u8 rssi; 33 }; 34 35 /* internal struct to pass radar data */ 36 struct ath_radar_data { 37 u8 pulse_bw_info; 38 u8 rssi; 39 u8 ext_rssi; 40 u8 pulse_length_ext; 41 u8 pulse_length_pri; 42 }; 43 44 /* convert pulse duration to usecs, considering clock mode */ 45 static u32 dur_to_usecs(struct ath_hw *ah, u32 dur) 46 { 47 const u32 AR93X_NSECS_PER_DUR = 800; 48 const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11); 49 u32 nsecs; 50 51 if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan)) 52 nsecs = dur * AR93X_NSECS_PER_DUR_FAST; 53 else 54 nsecs = dur * AR93X_NSECS_PER_DUR; 55 56 return (nsecs + 500) / 1000; 57 } 58 59 #define PRI_CH_RADAR_FOUND 0x01 60 #define EXT_CH_RADAR_FOUND 0x02 61 static bool 62 ath9k_postprocess_radar_event(struct ath_softc *sc, 63 struct ath_radar_data *are, 64 struct dfs_radar_pulse *drp) 65 { 66 u8 rssi; 67 u16 dur; 68 69 ath_dbg(ath9k_hw_common(sc->sc_ah), DFS, 70 "pulse_bw_info=0x%x, pri,ext len/rssi=(%u/%u, %u/%u)\n", 71 are->pulse_bw_info, 72 are->pulse_length_pri, are->rssi, 73 are->pulse_length_ext, are->ext_rssi); 74 75 /* 76 * Only the last 2 bits of the BW info are relevant, they indicate 77 * which channel the radar was detected in. 78 */ 79 are->pulse_bw_info &= 0x03; 80 81 switch (are->pulse_bw_info) { 82 case PRI_CH_RADAR_FOUND: 83 /* radar in ctrl channel */ 84 dur = are->pulse_length_pri; 85 DFS_STAT_INC(sc, pri_phy_errors); 86 /* 87 * cannot use ctrl channel RSSI 88 * if extension channel is stronger 89 */ 90 rssi = (are->ext_rssi >= (are->rssi + 3)) ? 0 : are->rssi; 91 break; 92 case EXT_CH_RADAR_FOUND: 93 /* radar in extension channel */ 94 dur = are->pulse_length_ext; 95 DFS_STAT_INC(sc, ext_phy_errors); 96 /* 97 * cannot use extension channel RSSI 98 * if control channel is stronger 99 */ 100 rssi = (are->rssi >= (are->ext_rssi + 12)) ? 0 : are->ext_rssi; 101 break; 102 case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND): 103 /* 104 * Conducted testing, when pulse is on DC, both pri and ext 105 * durations are reported to be same 106 * 107 * Radiated testing, when pulse is on DC, different pri and 108 * ext durations are reported, so take the larger of the two 109 */ 110 if (are->pulse_length_ext >= are->pulse_length_pri) 111 dur = are->pulse_length_ext; 112 else 113 dur = are->pulse_length_pri; 114 DFS_STAT_INC(sc, dc_phy_errors); 115 116 /* when both are present use stronger one */ 117 rssi = (are->rssi < are->ext_rssi) ? are->ext_rssi : are->rssi; 118 break; 119 default: 120 /* 121 * Bogus bandwidth info was received in descriptor, 122 * so ignore this PHY error 123 */ 124 DFS_STAT_INC(sc, bwinfo_discards); 125 return false; 126 } 127 128 if (rssi == 0) { 129 DFS_STAT_INC(sc, rssi_discards); 130 return false; 131 } 132 133 /* 134 * TODO: check chirping pulses 135 * checks for chirping are dependent on the DFS regulatory domain 136 * used, which is yet TBD 137 */ 138 139 /* convert duration to usecs */ 140 drp->width = dur_to_usecs(sc->sc_ah, dur); 141 drp->rssi = rssi; 142 143 DFS_STAT_INC(sc, pulses_detected); 144 return true; 145 } 146 #undef PRI_CH_RADAR_FOUND 147 #undef EXT_CH_RADAR_FOUND 148 149 /* 150 * DFS: check PHY-error for radar pulse and feed the detector 151 */ 152 void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data, 153 struct ath_rx_status *rs, u64 mactime) 154 { 155 struct ath_radar_data ard; 156 u16 datalen; 157 char *vdata_end; 158 struct dfs_radar_pulse drp; 159 struct ath_hw *ah = sc->sc_ah; 160 struct ath_common *common = ath9k_hw_common(ah); 161 162 if ((!(rs->rs_phyerr != ATH9K_PHYERR_RADAR)) && 163 (!(rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT))) { 164 ath_dbg(common, DFS, 165 "Error: rs_phyer=0x%x not a radar error\n", 166 rs->rs_phyerr); 167 return; 168 } 169 170 datalen = rs->rs_datalen; 171 if (datalen == 0) { 172 DFS_STAT_INC(sc, datalen_discards); 173 return; 174 } 175 176 ard.rssi = rs->rs_rssi_ctl0; 177 ard.ext_rssi = rs->rs_rssi_ext0; 178 179 /* 180 * hardware stores this as 8 bit signed value. 181 * we will cap it at 0 if it is a negative number 182 */ 183 if (ard.rssi & 0x80) 184 ard.rssi = 0; 185 if (ard.ext_rssi & 0x80) 186 ard.ext_rssi = 0; 187 188 vdata_end = (char *)data + datalen; 189 ard.pulse_bw_info = vdata_end[-1]; 190 ard.pulse_length_ext = vdata_end[-2]; 191 ard.pulse_length_pri = vdata_end[-3]; 192 193 ath_dbg(common, DFS, 194 "bw_info=%d, length_pri=%d, length_ext=%d, " 195 "rssi_pri=%d, rssi_ext=%d\n", 196 ard.pulse_bw_info, ard.pulse_length_pri, ard.pulse_length_ext, 197 ard.rssi, ard.ext_rssi); 198 199 drp.freq = ah->curchan->channel; 200 drp.ts = mactime; 201 if (ath9k_postprocess_radar_event(sc, &ard, &drp)) { 202 static u64 last_ts; 203 ath_dbg(common, DFS, 204 "ath9k_dfs_process_phyerr: channel=%d, ts=%llu, " 205 "width=%d, rssi=%d, delta_ts=%llu\n", 206 drp.freq, drp.ts, drp.width, drp.rssi, drp.ts-last_ts); 207 last_ts = drp.ts; 208 /* 209 * TODO: forward pulse to pattern detector 210 * 211 * ieee80211_add_radar_pulse(drp.freq, drp.ts, 212 * drp.width, drp.rssi); 213 */ 214 } 215 } 216