Flesh out a new HAL method to fetch the radar PHY error frame information.

For the AR5211/AR5212, this is apparently a one byte pulse duration
counter value. It is only coded up here for the AR5212 as I don't have
any AR5211-series hardware to test it on.

This information was extracted from the Madwifi DFS branch along with
some local additions.

Please note - all this does is extract out the radar event duration,
it in no way reflects the presence of a radar. Further code is needed
to take a set of radar events and filter them to extract out correct
radar pulse trains (and ignore other events.)

For further information, please see:

http://wiki.freebsd.org/dev/ath_hal%284%29/RadarDetection

This includes references to the relevant patents which describe what
is going on.

Obtained from:	Madwifi

sys/dev/ath/ath_hal/ah.h

@@ -745,6 +745,17 @@ typedef enum {
 	HAL_QUIET_ADD_SWBA_RESP_TIME	= 0x4,	/* add beacon response time to next_start offset */
 } HAL_QUIET_FLAG;
 
+#define	HAL_DFS_EVENT_PRICH		0x0000001
+
+struct dfs_event {
+	uint64_t	re_full_ts;	/* 64-bit full timestamp from interrupt time */
+	uint32_t	re_ts;		/* Original 15 bit recv timestamp */
+	uint8_t		re_rssi;	/* rssi of radar event */
+	uint8_t		re_dur;		/* duration of radar pulse */
+	uint32_t	re_flags;	/* Flags (see above) */
+};
+typedef struct dfs_event HAL_DFS_EVENT;
+
 /*
  * Hardware Access Layer (HAL) API.
  *
@@ -928,6 +939,9 @@ struct ath_hal {
 				HAL_PHYERR_PARAM *pe);
 	void	  __ahdecl(*ah_getDfsThresh)(struct ath_hal *ah,
 				HAL_PHYERR_PARAM *pe);
+	HAL_BOOL  __ahdecl(*ah_procRadarEvent)(struct ath_hal *ah,
+				struct ath_rx_status *rxs, uint64_t fulltsf,
+				const char *buf, HAL_DFS_EVENT *event);
 
 	/* Key Cache Functions */
 	uint32_t __ahdecl(*ah_getKeyCacheSize)(struct ath_hal*);

sys/dev/ath/ath_hal/ar5212/ar5212.h

@@ -622,5 +622,8 @@ extern	HAL_BOOL ar5212IsNFCalInProgress(struct ath_hal *ah);
 extern	HAL_BOOL ar5212WaitNFCalComplete(struct ath_hal *ah, int i);
 extern	void ar5212EnableDfs(struct ath_hal *ah, HAL_PHYERR_PARAM *pe);
 extern	void ar5212GetDfsThresh(struct ath_hal *ah, HAL_PHYERR_PARAM *pe);
+extern	HAL_BOOL ar5212ProcessRadarEvent(struct ath_hal *ah,
+	    struct ath_rx_status *rxs, uint64_t fulltsf, const char *buf,
+	    HAL_DFS_EVENT *event);
 
 #endif	/* _ATH_AR5212_H_ */

sys/dev/ath/ath_hal/ar5212/ar5212_attach.c

@@ -132,6 +132,7 @@ static const struct ath_hal_private ar5212hal = {{
 	/* DFS Functions */
 	.ah_enableDfs			= ar5212EnableDfs,
 	.ah_getDfsThresh		= ar5212GetDfsThresh,
+	.ah_procRadarEvent		= ar5212ProcessRadarEvent,
 
 	/* Key Cache Functions */
 	.ah_getKeyCacheSize		= ar5212GetKeyCacheSize,

sys/dev/ath/ath_hal/ar5212/ar5212_misc.c

@@ -1180,3 +1180,47 @@ ar5212GetDfsThresh(struct ath_hal *ah, HAL_PHYERR_PARAM *pe)
 	pe->pe_extchannel = AH_FALSE;
 }
 
+/*
+ * Process the radar phy error and extract the pulse duration.
+ */
+HAL_BOOL
+ar5212ProcessRadarEvent(struct ath_hal *ah, struct ath_rx_status *rxs,
+    uint64_t fulltsf, const char *buf, HAL_DFS_EVENT *event)
+{
+	uint8_t dur;
+	uint8_t rssi;
+
+	/* Check whether the given phy error is a radar event */
+	if ((rxs->rs_phyerr != HAL_PHYERR_RADAR) &&
+	    (rxs->rs_phyerr != HAL_PHYERR_FALSE_RADAR_EXT))
+		return AH_FALSE;
+
+	/*
+	 * The first byte is the pulse width - if there's
+	 * no data, simply set the duration to 0
+	 */
+	if (rxs->rs_datalen >= 1)
+		/* The pulse width is byte 0 of the data */
+		dur = ((uint8_t) buf[0]) & 0xff;
+	else
+		dur = 0;
+
+	/* Pulse RSSI is the normal reported RSSI */
+	rssi = (uint8_t) rxs->rs_rssi;
+
+	/* 0 duration/rssi is not a valid radar event */
+	if (dur == 0 && rssi == 0)
+		return AH_FALSE;
+
+	HALDEBUG(ah, HAL_DEBUG_DFS, "%s: rssi=%d, dur=%d\n",
+	    __func__, rssi, dur);
+
+	/* Record the event */
+	event->re_full_ts = fulltsf;
+	event->re_ts = rxs->rs_tstamp;
+	event->re_rssi = rssi;
+	event->re_dur = dur;
+	event->re_flags = HAL_DFS_EVENT_PRICH;
+
+	return AH_TRUE;
+}

sys/dev/ath/ath_hal/ar5416/ar5416.h

@@ -205,6 +205,9 @@ extern	HAL_BOOL ar5416SetRifsDelay(struct ath_hal *ah,
 	    const struct ieee80211_channel *chan, HAL_BOOL enable);
 extern	void ar5416EnableDfs(struct ath_hal *ah, HAL_PHYERR_PARAM *pe);
 extern	void ar5416GetDfsThresh(struct ath_hal *ah, HAL_PHYERR_PARAM *pe);
+extern	HAL_BOOL ar5416ProcessRadarEvent(struct ath_hal *ah,
+	    struct ath_rx_status *rxs, uint64_t fulltsf, const char *buf,
+	    HAL_DFS_EVENT *event);
 
 extern	HAL_BOOL ar5416SetPowerMode(struct ath_hal *ah, HAL_POWER_MODE mode,
 		int setChip);

sys/dev/ath/ath_hal/ar5416/ar5416_attach.c

@@ -147,6 +147,7 @@ ar5416InitState(struct ath_hal_5416 *ahp5416, uint16_t devid, HAL_SOFTC sc,
 	/* DFS Functions */
 	ah->ah_enableDfs		= ar5416EnableDfs;
 	ah->ah_getDfsThresh		= ar5416GetDfsThresh;
+	ah->ah_procRadarEvent		= ar5416ProcessRadarEvent;
 
 	/* Power Management Functions */
 	ah->ah_setPowerMode		= ar5416SetPowerMode;

sys/dev/ath/ath_hal/ar5416/ar5416_misc.c

@@ -692,3 +692,19 @@ ar5416EnableDfs(struct ath_hal *ah, HAL_PHYERR_PARAM *pe)
 		OS_REG_WRITE(ah, AR_PHY_RADAR_1, val);
 	}
 }
+
+/*
+ * Extract the radar event information from the given phy error.
+ *
+ * Returns AH_TRUE if the phy error was actually a phy error,
+ * AH_FALSE if the phy error wasn't a phy error.
+ */
+HAL_BOOL
+ar5416ProcessRadarEvent(struct ath_hal *ah, struct ath_rx_status *rxs,
+    uint64_t fulltsf, const char *buf, HAL_DFS_EVENT *event)
+{
+	/*
+	 * For now, this isn't implemented.
+	 */
+	return AH_FALSE;
+}

sys/dev/ath/if_athvar.h

@@ -709,6 +709,8 @@ void	ath_intr(void *);
 	((*(_ah)->ah_enableDfs)((_ah), (_param)))
 #define	ath_hal_getdfsthresh(_ah, _param) \
 	((*(_ah)->ah_getDfsThresh)((_ah), (_param)))
+#define	ath_hal_procradarevent(_ah, _rxs, _fulltsf, _buf, _event) \
+	((*(_ah)->ah_procRadarEvent)((_ah), (_rxs), (_fulltsf), (_buf), (_event)))
 
 #define ath_hal_gpioCfgOutput(_ah, _gpio, _type) \
         ((*(_ah)->ah_gpioCfgOutput)((_ah), (_gpio), (_type)))