362 lines
10 KiB
C
362 lines
10 KiB
C
|
/*
|
||
|
|
* 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"
|
||
|
|
|
||
|
|
/* 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;
|
||
|
|
};
|
||
|
|
|
||
|
|
/**** begin: CHIRP ************************************************************/
|
||
|
|
|
||
|
|
/* min and max gradients for defined FCC chirping pulses, given by
|
||
|
|
* - 20MHz chirp width over a pulse width of 50us
|
||
|
|
* - 5MHz chirp width over a pulse width of 100us
|
||
|
|
*/
|
||
|
|
static const int BIN_DELTA_MIN = 1;
|
||
|
|
static const int BIN_DELTA_MAX = 10;
|
||
|
|
|
||
|
|
/* we need at least 3 deltas / 4 samples for a reliable chirp detection */
|
||
|
|
#define NUM_DIFFS 3
|
||
|
|
#define FFT_NUM_SAMPLES (NUM_DIFFS + 1)
|
||
|
|
|
||
|
|
/* Threshold for difference of delta peaks */
|
||
|
|
static const int MAX_DIFF = 2;
|
||
|
|
|
||
|
|
/* width range to be checked for chirping */
|
||
|
|
static const int MIN_CHIRP_PULSE_WIDTH = 20;
|
||
|
|
static const int MAX_CHIRP_PULSE_WIDTH = 110;
|
||
|
|
|
||
|
|
struct ath9k_dfs_fft_20 {
|
||
|
|
u8 bin[28];
|
||
|
|
u8 lower_bins[3];
|
||
|
|
} __packed;
|
||
|
|
struct ath9k_dfs_fft_40 {
|
||
|
|
u8 bin[64];
|
||
|
|
u8 lower_bins[3];
|
||
|
|
u8 upper_bins[3];
|
||
|
|
} __packed;
|
||
|
|
|
||
|
|
static inline int fft_max_index(u8 *bins)
|
||
|
|
{
|
||
|
|
return (bins[2] & 0xfc) >> 2;
|
||
|
|
}
|
||
|
|
static inline int fft_max_magnitude(u8 *bins)
|
||
|
|
{
|
||
|
|
return (bins[0] & 0xc0) >> 6 | bins[1] << 2 | (bins[2] & 0x03) << 10;
|
||
|
|
}
|
||
|
|
static inline u8 fft_bitmap_weight(u8 *bins)
|
||
|
|
{
|
||
|
|
return bins[0] & 0x3f;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int ath9k_get_max_index_ht40(struct ath9k_dfs_fft_40 *fft,
|
||
|
|
bool is_ctl, bool is_ext)
|
||
|
|
{
|
||
|
|
const int DFS_UPPER_BIN_OFFSET = 64;
|
||
|
|
/* if detected radar on both channels, select the significant one */
|
||
|
|
if (is_ctl && is_ext) {
|
||
|
|
/* first check wether channels have 'strong' bins */
|
||
|
|
is_ctl = fft_bitmap_weight(fft->lower_bins) != 0;
|
||
|
|
is_ext = fft_bitmap_weight(fft->upper_bins) != 0;
|
||
|
|
|
||
|
|
/* if still unclear, take higher magnitude */
|
||
|
|
if (is_ctl && is_ext) {
|
||
|
|
int mag_lower = fft_max_magnitude(fft->lower_bins);
|
||
|
|
int mag_upper = fft_max_magnitude(fft->upper_bins);
|
||
|
|
if (mag_upper > mag_lower)
|
||
|
|
is_ctl = false;
|
||
|
|
else
|
||
|
|
is_ext = false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (is_ctl)
|
||
|
|
return fft_max_index(fft->lower_bins);
|
||
|
|
return fft_max_index(fft->upper_bins) + DFS_UPPER_BIN_OFFSET;
|
||
|
|
}
|
||
|
|
static bool ath9k_check_chirping(struct ath_softc *sc, u8 *data,
|
||
|
|
int datalen, bool is_ctl, bool is_ext)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
int max_bin[FFT_NUM_SAMPLES];
|
||
|
|
struct ath_hw *ah = sc->sc_ah;
|
||
|
|
struct ath_common *common = ath9k_hw_common(ah);
|
||
|
|
int prev_delta;
|
||
|
|
|
||
|
|
if (IS_CHAN_HT40(ah->curchan)) {
|
||
|
|
struct ath9k_dfs_fft_40 *fft = (struct ath9k_dfs_fft_40 *) data;
|
||
|
|
int num_fft_packets = datalen / sizeof(*fft);
|
||
|
|
if (num_fft_packets == 0)
|
||
|
|
return false;
|
||
|
|
|
||
|
|
ath_dbg(common, DFS, "HT40: datalen=%d, num_fft_packets=%d\n",
|
||
|
|
datalen, num_fft_packets);
|
||
|
|
if (num_fft_packets < FFT_NUM_SAMPLES) {
|
||
|
|
ath_dbg(common, DFS, "not enough packets for chirp\n");
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
/* HW sometimes adds 2 garbage bytes in front of FFT samples */
|
||
|
|
if ((datalen % sizeof(*fft)) == 2) {
|
||
|
|
fft = (struct ath9k_dfs_fft_40 *) (data + 2);
|
||
|
|
ath_dbg(common, DFS, "fixing datalen by 2\n");
|
||
|
|
}
|
||
|
|
if (IS_CHAN_HT40MINUS(ah->curchan))
|
||
|
|
swap(is_ctl, is_ext);
|
||
|
|
|
||
|
|
for (i = 0; i < FFT_NUM_SAMPLES; i++)
|
||
|
|
max_bin[i] = ath9k_get_max_index_ht40(fft + i, is_ctl,
|
||
|
|
is_ext);
|
||
|
|
} else {
|
||
|
|
struct ath9k_dfs_fft_20 *fft = (struct ath9k_dfs_fft_20 *) data;
|
||
|
|
int num_fft_packets = datalen / sizeof(*fft);
|
||
|
|
if (num_fft_packets == 0)
|
||
|
|
return false;
|
||
|
|
ath_dbg(common, DFS, "HT20: datalen=%d, num_fft_packets=%d\n",
|
||
|
|
datalen, num_fft_packets);
|
||
|
|
if (num_fft_packets < FFT_NUM_SAMPLES) {
|
||
|
|
ath_dbg(common, DFS, "not enough packets for chirp\n");
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
/* in ht20, this is a 6-bit signed number => shift it to 0 */
|
||
|
|
for (i = 0; i < FFT_NUM_SAMPLES; i++)
|
||
|
|
max_bin[i] = fft_max_index(fft[i].lower_bins) ^ 0x20;
|
||
|
|
}
|
||
|
|
ath_dbg(common, DFS, "bin_max = [%d, %d, %d, %d]\n",
|
||
|
|
max_bin[0], max_bin[1], max_bin[2], max_bin[3]);
|
||
|
|
|
||
|
|
/* Check for chirp attributes within specs
|
||
|
|
* a) delta of adjacent max_bins is within range
|
||
|
|
* b) delta of adjacent deltas are within tolerance
|
||
|
|
*/
|
||
|
|
prev_delta = 0;
|
||
|
|
for (i = 0; i < NUM_DIFFS; i++) {
|
||
|
|
int ddelta = -1;
|
||
|
|
int delta = max_bin[i + 1] - max_bin[i];
|
||
|
|
|
||
|
|
/* ensure gradient is within valid range */
|
||
|
|
if (abs(delta) < BIN_DELTA_MIN || abs(delta) > BIN_DELTA_MAX) {
|
||
|
|
ath_dbg(common, DFS, "CHIRP: invalid delta %d "
|
||
|
|
"in sample %d\n", delta, i);
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (i == 0)
|
||
|
|
goto done;
|
||
|
|
ddelta = delta - prev_delta;
|
||
|
|
if (abs(ddelta) > MAX_DIFF) {
|
||
|
|
ath_dbg(common, DFS, "CHIRP: ddelta %d too high\n",
|
||
|
|
ddelta);
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
done:
|
||
|
|
ath_dbg(common, DFS, "CHIRP - %d: delta=%d, ddelta=%d\n",
|
||
|
|
i, delta, ddelta);
|
||
|
|
prev_delta = delta;
|
||
|
|
}
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
/**** end: CHIRP **************************************************************/
|
||
|
|
|
||
|
|
/* 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 *ard,
|
||
|
|
struct pulse_event *pe)
|
||
|
|
{
|
||
|
|
u8 rssi;
|
||
|
|
u16 dur;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Only the last 2 bits of the BW info are relevant, they indicate
|
||
|
|
* which channel the radar was detected in.
|
||
|
|
*/
|
||
|
|
ard->pulse_bw_info &= 0x03;
|
||
|
|
|
||
|
|
switch (ard->pulse_bw_info) {
|
||
|
|
case PRI_CH_RADAR_FOUND:
|
||
|
|
/* radar in ctrl channel */
|
||
|
|
dur = ard->pulse_length_pri;
|
||
|
|
DFS_STAT_INC(sc, pri_phy_errors);
|
||
|
|
/*
|
||
|
|
* cannot use ctrl channel RSSI
|
||
|
|
* if extension channel is stronger
|
||
|
|
*/
|
||
|
|
rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi;
|
||
|
|
break;
|
||
|
|
case EXT_CH_RADAR_FOUND:
|
||
|
|
/* radar in extension channel */
|
||
|
|
dur = ard->pulse_length_ext;
|
||
|
|
DFS_STAT_INC(sc, ext_phy_errors);
|
||
|
|
/*
|
||
|
|
* cannot use extension channel RSSI
|
||
|
|
* if control channel is stronger
|
||
|
|
*/
|
||
|
|
rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->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 (ard->pulse_length_ext >= ard->pulse_length_pri)
|
||
|
|
dur = ard->pulse_length_ext;
|
||
|
|
else
|
||
|
|
dur = ard->pulse_length_pri;
|
||
|
|
DFS_STAT_INC(sc, dc_phy_errors);
|
||
|
|
|
||
|
|
/* when both are present use stronger one */
|
||
|
|
rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->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;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* convert duration to usecs */
|
||
|
|
pe->width = dur_to_usecs(sc->sc_ah, dur);
|
||
|
|
pe->rssi = rssi;
|
||
|
|
|
||
|
|
DFS_STAT_INC(sc, pulses_detected);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void
|
||
|
|
ath9k_dfs_process_radar_pulse(struct ath_softc *sc, struct pulse_event *pe)
|
||
|
|
{
|
||
|
|
struct dfs_pattern_detector *pd = sc->dfs_detector;
|
||
|
|
DFS_STAT_INC(sc, pulses_processed);
|
||
|
|
if (pd == NULL)
|
||
|
|
return;
|
||
|
|
if (!pd->add_pulse(pd, pe, NULL))
|
||
|
|
return;
|
||
|
|
DFS_STAT_INC(sc, radar_detected);
|
||
|
|
ieee80211_radar_detected(sc->hw);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* 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 pulse_event pe;
|
||
|
|
struct ath_hw *ah = sc->sc_ah;
|
||
|
|
struct ath_common *common = ath9k_hw_common(ah);
|
||
|
|
|
||
|
|
DFS_STAT_INC(sc, pulses_total);
|
||
|
|
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);
|
||
|
|
DFS_STAT_INC(sc, pulses_no_dfs);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
datalen = rs->rs_datalen;
|
||
|
|
if (datalen == 0) {
|
||
|
|
DFS_STAT_INC(sc, datalen_discards);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
ard.rssi = rs->rs_rssi_ctl[0];
|
||
|
|
ard.ext_rssi = rs->rs_rssi_ext[0];
|
||
|
|
|
||
|
|
/*
|
||
|
|
* 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 = data + datalen;
|
||
|
|
ard.pulse_bw_info = vdata_end[-1];
|
||
|
|
ard.pulse_length_ext = vdata_end[-2];
|
||
|
|
ard.pulse_length_pri = vdata_end[-3];
|
||
|
|
pe.freq = ah->curchan->channel;
|
||
|
|
pe.ts = mactime;
|
||
|
|
if (!ath9k_postprocess_radar_event(sc, &ard, &pe))
|
||
|
|
return;
|
||
|
|
|
||
|
|
if (pe.width > MIN_CHIRP_PULSE_WIDTH &&
|
||
|
|
pe.width < MAX_CHIRP_PULSE_WIDTH) {
|
||
|
|
bool is_ctl = !!(ard.pulse_bw_info & PRI_CH_RADAR_FOUND);
|
||
|
|
bool is_ext = !!(ard.pulse_bw_info & EXT_CH_RADAR_FOUND);
|
||
|
|
int clen = datalen - 3;
|
||
|
|
pe.chirp = ath9k_check_chirping(sc, data, clen, is_ctl, is_ext);
|
||
|
|
} else {
|
||
|
|
pe.chirp = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
ath_dbg(common, DFS,
|
||
|
|
"ath9k_dfs_process_phyerr: type=%d, freq=%d, ts=%llu, "
|
||
|
|
"width=%d, rssi=%d, delta_ts=%llu\n",
|
||
|
|
ard.pulse_bw_info, pe.freq, pe.ts, pe.width, pe.rssi,
|
||
|
|
pe.ts - sc->dfs_prev_pulse_ts);
|
||
|
|
sc->dfs_prev_pulse_ts = pe.ts;
|
||
|
|
if (ard.pulse_bw_info & PRI_CH_RADAR_FOUND)
|
||
|
|
ath9k_dfs_process_radar_pulse(sc, &pe);
|
||
|
|
if (IS_CHAN_HT40(ah->curchan) &&
|
||
|
|
ard.pulse_bw_info & EXT_CH_RADAR_FOUND) {
|
||
|
|
pe.freq += IS_CHAN_HT40PLUS(ah->curchan) ? 20 : -20;
|
||
|
|
ath9k_dfs_process_radar_pulse(sc, &pe);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#undef PRI_CH_RADAR_FOUND
|
||
|
|
#undef EXT_CH_RADAR_FOUND
|