[deliverable/linux.git] / drivers / net / wireless / ath / ath9k / dfs.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;
};

/* 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;
	}

	/*
	 * TODO: check chirping pulses
	 *	 checks for chirping are dependent on the DFS regulatory domain
	 *	 used, which is yet TBD
	 */

	/* 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))
		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 = (char *)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;

	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 (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
Commit	Line	Data
29942bc1 ZK	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
29942bc1 ZK	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,
56dc389f ZK	52	struct ath_radar_data *ard,
56dc389f ZK	53	struct pulse_event *pe)
29942bc1 ZK	54	{
	55	u8 rssi;
	56	u16 dur;
	57
29942bc1 ZK	58	/*
	59	* Only the last 2 bits of the BW info are relevant, they indicate
	60	* which channel the radar was detected in.
	61	*/
56dc389f	62	ard->pulse_bw_info &= 0x03;
29942bc1	63
56dc389f	64	switch (ard->pulse_bw_info) {
29942bc1 ZK	65	case PRI_CH_RADAR_FOUND:
29942bc1 ZK	66	/* radar in ctrl channel */
56dc389f	67	dur = ard->pulse_length_pri;
29942bc1 ZK	68	DFS_STAT_INC(sc, pri_phy_errors);
	69	/*
	70	* cannot use ctrl channel RSSI
	71	* if extension channel is stronger
	72	*/
56dc389f	73	rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi;
29942bc1 ZK	74	break;
	75	case EXT_CH_RADAR_FOUND:
	76	/* radar in extension channel */
56dc389f	77	dur = ard->pulse_length_ext;
29942bc1 ZK	78	DFS_STAT_INC(sc, ext_phy_errors);
	79	/*
	80	* cannot use extension channel RSSI
	81	* if control channel is stronger
	82	*/
56dc389f	83	rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->ext_rssi;
29942bc1 ZK	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	*/
56dc389f ZK	93	if (ard->pulse_length_ext >= ard->pulse_length_pri)
56dc389f ZK	94	dur = ard->pulse_length_ext;
29942bc1	95	else
56dc389f	96	dur = ard->pulse_length_pri;
29942bc1 ZK	97	DFS_STAT_INC(sc, dc_phy_errors);
	98
	99	/* when both are present use stronger one */
56dc389f	100	rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->rssi;
29942bc1 ZK	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 */
56dc389f ZK	123	pe->width = dur_to_usecs(sc->sc_ah, dur);
56dc389f ZK	124	pe->rssi = rssi;
29942bc1 ZK	125
	126	DFS_STAT_INC(sc, pulses_detected);
	127	return true;
	128	}
58766977 ZK	129
	130	static void
	131	ath9k_dfs_process_radar_pulse(struct ath_softc sc, struct pulse_event pe)
	132	{
	133	struct dfs_pattern_detector *pd = sc->dfs_detector;
	134	DFS_STAT_INC(sc, pulses_processed);
	135	if (pd == NULL)
	136	return;
	137	if (!pd->add_pulse(pd, pe))
	138	return;
	139	DFS_STAT_INC(sc, radar_detected);
	140	ieee80211_radar_detected(sc->hw);
	141	}
29942bc1 ZK	142
	143	/*
	144	* DFS: check PHY-error for radar pulse and feed the detector
	145	*/
	146	void ath9k_dfs_process_phyerr(struct ath_softc sc, void data,
	147	struct ath_rx_status *rs, u64 mactime)
	148	{
	149	struct ath_radar_data ard;
	150	u16 datalen;
	151	char *vdata_end;
56dc389f	152	struct pulse_event pe;
29942bc1 ZK	153	struct ath_hw *ah = sc->sc_ah;
	154	struct ath_common *common = ath9k_hw_common(ah);
	155
b96f20b3	156	DFS_STAT_INC(sc, pulses_total);
56dc389f ZK	157	if ((rs->rs_phyerr != ATH9K_PHYERR_RADAR) &&
56dc389f ZK	158	(rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT)) {
ec9a5705	159	ath_dbg(common, DFS,
29942bc1 ZK	160	"Error: rs_phyer=0x%x not a radar error\n",
29942bc1 ZK	161	rs->rs_phyerr);
b96f20b3	162	DFS_STAT_INC(sc, pulses_no_dfs);
29942bc1 ZK	163	return;
	164	}
	165
	166	datalen = rs->rs_datalen;
	167	if (datalen == 0) {
	168	DFS_STAT_INC(sc, datalen_discards);
	169	return;
	170	}
	171
e45e91d8 FF	172	ard.rssi = rs->rs_rssi_ctl[0];
e45e91d8 FF	173	ard.ext_rssi = rs->rs_rssi_ext[0];
29942bc1 ZK	174
	175	/*
	176	* hardware stores this as 8 bit signed value.
	177	* we will cap it at 0 if it is a negative number
	178	*/
	179	if (ard.rssi & 0x80)
	180	ard.rssi = 0;
	181	if (ard.ext_rssi & 0x80)
	182	ard.ext_rssi = 0;
	183
	184	vdata_end = (char *)data + datalen;
	185	ard.pulse_bw_info = vdata_end[-1];
	186	ard.pulse_length_ext = vdata_end[-2];
	187	ard.pulse_length_pri = vdata_end[-3];
56dc389f ZK	188	pe.freq = ah->curchan->channel;
56dc389f ZK	189	pe.ts = mactime;
58766977 ZK	190	if (!ath9k_postprocess_radar_event(sc, &ard, &pe))
	191	return;
	192
	193	ath_dbg(common, DFS,
	194	"ath9k_dfs_process_phyerr: type=%d, freq=%d, ts=%llu, "
	195	"width=%d, rssi=%d, delta_ts=%llu\n",
	196	ard.pulse_bw_info, pe.freq, pe.ts, pe.width, pe.rssi,
	197	pe.ts - sc->dfs_prev_pulse_ts);
	198	sc->dfs_prev_pulse_ts = pe.ts;
	199	if (ard.pulse_bw_info & PRI_CH_RADAR_FOUND)
	200	ath9k_dfs_process_radar_pulse(sc, &pe);
	201	if (ard.pulse_bw_info & EXT_CH_RADAR_FOUND) {
	202	pe.freq += IS_CHAN_HT40PLUS(ah->curchan) ? 20 : -20;
	203	ath9k_dfs_process_radar_pulse(sc, &pe);
29942bc1 ZK	204	}
29942bc1 ZK	205	}
58766977 ZK	206	#undef PRI_CH_RADAR_FOUND
58766977 ZK	207	#undef EXT_CH_RADAR_FOUND