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Diffstat (limited to 'drivers/net/wireless/ath/ath9k/dfs.c')
-rw-r--r--drivers/net/wireless/ath/ath9k/dfs.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/dfs.c b/drivers/net/wireless/ath/ath9k/dfs.c
new file mode 100644
index 0000000..f4f56af
--- /dev/null
+++ b/drivers/net/wireless/ath/ath9k/dfs.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2008-2011 Atheros Communications Inc.
+ * Copyright (c) 2011 Neratec Solutions AG
+ *
+ * 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 "hw.h"
+#include "hw-ops.h"
+#include "ath9k.h"
+#include "dfs.h"
+#include "dfs_debug.h"
+
+/*
+ * TODO: move into or synchronize this with generic header
+ * as soon as IF is defined
+ */
+struct dfs_radar_pulse {
+ u16 freq;
+ u64 ts;
+ u32 width;
+ u8 rssi;
+};
+
+/* internal struct to pass radar data */
+struct ath_radar_data {
+ u8 pulse_bw_info;
+ u8 rssi;
+ u8 ext_rssi;
+ u8 pulse_length_ext;
+ u8 pulse_length_pri;
+};
+
+/* convert pulse duration to usecs, considering clock mode */
+static u32 dur_to_usecs(struct ath_hw *ah, u32 dur)
+{
+ const u32 AR93X_NSECS_PER_DUR = 800;
+ const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11);
+ u32 nsecs;
+
+ if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan))
+ nsecs = dur * AR93X_NSECS_PER_DUR_FAST;
+ else
+ nsecs = dur * AR93X_NSECS_PER_DUR;
+
+ return (nsecs + 500) / 1000;
+}
+
+#define PRI_CH_RADAR_FOUND 0x01
+#define EXT_CH_RADAR_FOUND 0x02
+static bool
+ath9k_postprocess_radar_event(struct ath_softc *sc,
+ struct ath_radar_data *are,
+ struct dfs_radar_pulse *drp)
+{
+ u8 rssi;
+ u16 dur;
+
+ ath_dbg(ath9k_hw_common(sc->sc_ah), DFS,
+ "pulse_bw_info=0x%x, pri,ext len/rssi=(%u/%u, %u/%u)\n",
+ are->pulse_bw_info,
+ are->pulse_length_pri, are->rssi,
+ are->pulse_length_ext, are->ext_rssi);
+
+ /*
+ * Only the last 2 bits of the BW info are relevant, they indicate
+ * which channel the radar was detected in.
+ */
+ are->pulse_bw_info &= 0x03;
+
+ switch (are->pulse_bw_info) {
+ case PRI_CH_RADAR_FOUND:
+ /* radar in ctrl channel */
+ dur = are->pulse_length_pri;
+ DFS_STAT_INC(sc, pri_phy_errors);
+ /*
+ * cannot use ctrl channel RSSI
+ * if extension channel is stronger
+ */
+ rssi = (are->ext_rssi >= (are->rssi + 3)) ? 0 : are->rssi;
+ break;
+ case EXT_CH_RADAR_FOUND:
+ /* radar in extension channel */
+ dur = are->pulse_length_ext;
+ DFS_STAT_INC(sc, ext_phy_errors);
+ /*
+ * cannot use extension channel RSSI
+ * if control channel is stronger
+ */
+ rssi = (are->rssi >= (are->ext_rssi + 12)) ? 0 : are->ext_rssi;
+ break;
+ case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND):
+ /*
+ * Conducted testing, when pulse is on DC, both pri and ext
+ * durations are reported to be same
+ *
+ * Radiated testing, when pulse is on DC, different pri and
+ * ext durations are reported, so take the larger of the two
+ */
+ if (are->pulse_length_ext >= are->pulse_length_pri)
+ dur = are->pulse_length_ext;
+ else
+ dur = are->pulse_length_pri;
+ DFS_STAT_INC(sc, dc_phy_errors);
+
+ /* when both are present use stronger one */
+ rssi = (are->rssi < are->ext_rssi) ? are->ext_rssi : are->rssi;
+ break;
+ default:
+ /*
+ * Bogus bandwidth info was received in descriptor,
+ * so ignore this PHY error
+ */
+ DFS_STAT_INC(sc, bwinfo_discards);
+ return false;
+ }
+
+ if (rssi == 0) {
+ DFS_STAT_INC(sc, rssi_discards);
+ return false;
+ }
+
+ /*
+ * TODO: check chirping pulses
+ * checks for chirping are dependent on the DFS regulatory domain
+ * used, which is yet TBD
+ */
+
+ /* convert duration to usecs */
+ drp->width = dur_to_usecs(sc->sc_ah, dur);
+ drp->rssi = rssi;
+
+ DFS_STAT_INC(sc, pulses_detected);
+ return true;
+}
+#undef PRI_CH_RADAR_FOUND
+#undef EXT_CH_RADAR_FOUND
+
+/*
+ * DFS: check PHY-error for radar pulse and feed the detector
+ */
+void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data,
+ struct ath_rx_status *rs, u64 mactime)
+{
+ struct ath_radar_data ard;
+ u16 datalen;
+ char *vdata_end;
+ struct dfs_radar_pulse drp;
+ struct ath_hw *ah = sc->sc_ah;
+ struct ath_common *common = ath9k_hw_common(ah);
+
+ if ((!(rs->rs_phyerr != ATH9K_PHYERR_RADAR)) &&
+ (!(rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT))) {
+ ath_dbg(common, DFS,
+ "Error: rs_phyer=0x%x not a radar error\n",
+ rs->rs_phyerr);
+ return;
+ }
+
+ datalen = rs->rs_datalen;
+ if (datalen == 0) {
+ DFS_STAT_INC(sc, datalen_discards);
+ return;
+ }
+
+ ard.rssi = rs->rs_rssi_ctl0;
+ ard.ext_rssi = rs->rs_rssi_ext0;
+
+ /*
+ * hardware stores this as 8 bit signed value.
+ * we will cap it at 0 if it is a negative number
+ */
+ if (ard.rssi & 0x80)
+ ard.rssi = 0;
+ if (ard.ext_rssi & 0x80)
+ ard.ext_rssi = 0;
+
+ vdata_end = (char *)data + datalen;
+ ard.pulse_bw_info = vdata_end[-1];
+ ard.pulse_length_ext = vdata_end[-2];
+ ard.pulse_length_pri = vdata_end[-3];
+
+ ath_dbg(common, DFS,
+ "bw_info=%d, length_pri=%d, length_ext=%d, "
+ "rssi_pri=%d, rssi_ext=%d\n",
+ ard.pulse_bw_info, ard.pulse_length_pri, ard.pulse_length_ext,
+ ard.rssi, ard.ext_rssi);
+
+ drp.freq = ah->curchan->channel;
+ drp.ts = mactime;
+ if (ath9k_postprocess_radar_event(sc, &ard, &drp)) {
+ static u64 last_ts;
+ ath_dbg(common, DFS,
+ "ath9k_dfs_process_phyerr: channel=%d, ts=%llu, "
+ "width=%d, rssi=%d, delta_ts=%llu\n",
+ drp.freq, drp.ts, drp.width, drp.rssi, drp.ts-last_ts);
+ last_ts = drp.ts;
+ /*
+ * TODO: forward pulse to pattern detector
+ *
+ * ieee80211_add_radar_pulse(drp.freq, drp.ts,
+ * drp.width, drp.rssi);
+ */
+ }
+}