ath5k: Implement antenna control

* Add code to support the various antenna scenarios supported by hw

 * For now hardcode the default scenario (single or dual omnis with
 tx/rx diversity working and tx antenna handled by session -hw keeps
 track on which antenna it got ack from each ap/station and maps each
 ap/station to one of the antennas-).

 Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
 Signed-off-by: Bob Copeland <me@bobcopeland.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/ath5k.h

@@ -209,7 +209,6 @@
 #define AR5K_TUNE_MAX_TXPOWER			63
 #define AR5K_TUNE_DEFAULT_TXPOWER		25
 #define AR5K_TUNE_TPC_TXPOWER			false
-#define AR5K_TUNE_ANT_DIVERSITY			true
 #define AR5K_TUNE_HWTXTRIES			4
 
 #define AR5K_INIT_CARR_SENSE_EN			1
@@ -420,6 +419,17 @@ enum ath5k_driver_mode {
 	AR5K_MODE_MAX		=	5
 };
 
+enum ath5k_ant_mode {
+	AR5K_ANTMODE_DEFAULT	= 0,	/* default antenna setup */
+	AR5K_ANTMODE_FIXED_A	= 1,	/* only antenna A is present */
+	AR5K_ANTMODE_FIXED_B	= 2,	/* only antenna B is present */
+	AR5K_ANTMODE_SINGLE_AP	= 3,	/* sta locked on a single ap */
+	AR5K_ANTMODE_SECTOR_AP	= 4,	/* AP with tx antenna set on tx desc */
+	AR5K_ANTMODE_SECTOR_STA	= 5,	/* STA with tx antenna set on tx desc */
+	AR5K_ANTMODE_DEBUG	= 6,	/* Debug mode -A -> Rx, B-> Tx- */
+	AR5K_ANTMODE_MAX,
+};
+
 
 /****************\
   TX DEFINITIONS
@@ -1051,8 +1061,11 @@ struct ath5k_hw {
 	bool			ah_software_retry;
 	u32			ah_limit_tx_retries;
 
-	u32			ah_antenna[AR5K_EEPROM_N_MODES][AR5K_ANT_MAX];
-	bool			ah_ant_diversity;
+	/* Antenna Control */
+	u32			ah_ant_ctl[AR5K_EEPROM_N_MODES][AR5K_ANT_MAX];
+	u8			ah_ant_mode;
+	u8			ah_tx_ant;
+	u8			ah_def_ant;
 
 	u8			ah_sta_id[ETH_ALEN];
 
@@ -1267,9 +1280,11 @@ extern int ath5k_hw_phy_calibrate(struct ath5k_hw *ah, struct ieee80211_channel
 extern int ath5k_hw_noise_floor_calibration(struct ath5k_hw *ah, short freq);
 /* Misc PHY functions */
 extern u16 ath5k_hw_radio_revision(struct ath5k_hw *ah, unsigned int chan);
-extern void ath5k_hw_set_def_antenna(struct ath5k_hw *ah, unsigned int ant);
-extern unsigned int ath5k_hw_get_def_antenna(struct ath5k_hw *ah);
 extern int ath5k_hw_phy_disable(struct ath5k_hw *ah);
+/* Antenna control */
+extern void ath5k_hw_set_antenna_mode(struct ath5k_hw *ah, u8 ant_mode);
+extern void ath5k_hw_set_def_antenna(struct ath5k_hw *ah, u8 ant);
+extern unsigned int ath5k_hw_get_def_antenna(struct ath5k_hw *ah);
 /* TX power setup */
 extern int ath5k_hw_txpower(struct ath5k_hw *ah, struct ieee80211_channel *channel, u8 ee_mode, u8 txpower);
 extern int ath5k_hw_set_txpower_limit(struct ath5k_hw *ah, u8 txpower);

drivers/net/wireless/ath/ath5k/attach.c

@@ -133,7 +133,6 @@ struct ath5k_hw *ath5k_hw_attach(struct ath5k_softc *sc, u8 mac_version)
 	ah->ah_cw_min = AR5K_TUNE_CWMIN;
 	ah->ah_limit_tx_retries = AR5K_INIT_TX_RETRY;
 	ah->ah_software_retry = false;
-	ah->ah_ant_diversity = AR5K_TUNE_ANT_DIVERSITY;
 
 	/*
 	 * Set the mac version based on the pci id

drivers/net/wireless/ath/ath5k/base.c

@@ -1279,7 +1279,7 @@ ath5k_txbuf_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
 		ieee80211_get_hdrlen_from_skb(skb), AR5K_PKT_TYPE_NORMAL,
 		(sc->power_level * 2),
 		hw_rate,
-		info->control.rates[0].count, keyidx, 0, flags,
+		info->control.rates[0].count, keyidx, ah->ah_tx_ant, flags,
 		cts_rate, duration);
 	if (ret)
 		goto err_unmap;
@@ -2009,7 +2009,8 @@ ath5k_beacon_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
 	struct	ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ath5k_hw *ah = sc->ah;
 	struct ath5k_desc *ds;
-	int ret, antenna = 0;
+	int ret = 0;
+	u8 antenna;
 	u32 flags;
 
 	bf->skbaddr = pci_map_single(sc->pdev, skb->data, skb->len,
@@ -2023,23 +2024,35 @@ ath5k_beacon_setup(struct ath5k_softc *sc, struct ath5k_buf *bf)
 	}
 
 	ds = bf->desc;
+	antenna = ah->ah_tx_ant;
 
 	flags = AR5K_TXDESC_NOACK;
 	if (sc->opmode == NL80211_IFTYPE_ADHOC && ath5k_hw_hasveol(ah)) {
 		ds->ds_link = bf->daddr;	/* self-linked */
 		flags |= AR5K_TXDESC_VEOL;
-		/*
-		 * Let hardware handle antenna switching if txantenna is not set
-		 */
-	} else {
+	} else
 		ds->ds_link = 0;
-		/*
-		 * Switch antenna every 4 beacons if txantenna is not set
-		 * XXX assumes two antennas
-		 */
-		if (antenna == 0)
-			antenna = sc->bsent & 4 ? 2 : 1;
-	}
+
+	/*
+	 * If we use multiple antennas on AP and use
+	 * the Sectored AP scenario, switch antenna every
+	 * 4 beacons to make sure everybody hears our AP.
+	 * When a client tries to associate, hw will keep
+	 * track of the tx antenna to be used for this client
+	 * automaticaly, based on ACKed packets.
+	 *
+	 * Note: AP still listens and transmits RTS on the
+	 * default antenna which is supposed to be an omni.
+	 *
+	 * Note2: On sectored scenarios it's possible to have
+	 * multiple antennas (1omni -the default- and 14 sectors)
+	 * so if we choose to actually support this mode we need
+	 * to allow user to set how many antennas we have and tweak
+	 * the code below to send beacons on all of them.
+	 */
+	if (ah->ah_ant_mode == AR5K_ANTMODE_SECTOR_AP)
+		antenna = sc->bsent & 4 ? 2 : 1;
+
 
 	/* FIXME: If we are in g mode and rate is a CCK rate
 	 * subtract ah->ah_txpower.txp_cck_ofdm_pwr_delta
@@ -2752,12 +2765,16 @@ ath5k_config(struct ieee80211_hw *hw, u32 changed)
 	struct ath5k_softc *sc = hw->priv;
 	struct ath5k_hw *ah = sc->ah;
 	struct ieee80211_conf *conf = &hw->conf;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&sc->lock);
 
 	sc->bintval = conf->beacon_int;
 
+	ret = ath5k_chan_set(sc, conf->channel);
+	if (ret < 0)
+		return ret;
+
 	if ((changed & IEEE80211_CONF_CHANGE_POWER) &&
 	(sc->power_level != conf->power_level)) {
 		sc->power_level = conf->power_level;
@@ -2766,10 +2783,27 @@ ath5k_config(struct ieee80211_hw *hw, u32 changed)
 		ath5k_hw_set_txpower_limit(ah, (conf->power_level * 2));
 	}
 
-	ret = ath5k_chan_set(sc, conf->channel);
+	/* TODO:
+	 * 1) Move this on config_interface and handle each case
+	 * separately eg. when we have only one STA vif, use
+	 * AR5K_ANTMODE_SINGLE_AP
+	 *
+	 * 2) Allow the user to change antenna mode eg. when only
+	 * one antenna is present
+	 *
+	 * 3) Allow the user to set default/tx antenna when possible
+	 *
+	 * 4) Default mode should handle 90% of the cases, together
+	 * with fixed a/b and single AP modes we should be able to
+	 * handle 99%. Sectored modes are extreme cases and i still
+	 * haven't found a usage for them. If we decide to support them,
+	 * then we must allow the user to set how many tx antennas we
+	 * have available
+	 */
+	ath5k_hw_set_antenna_mode(ah, AR5K_ANTMODE_DEFAULT);
 
 	mutex_unlock(&sc->lock);
-	return ret;
+	return 0;
 }
 
 #define SUPPORTED_FIF_FLAGS \

drivers/net/wireless/ath/ath5k/eeprom.c

@@ -208,16 +208,16 @@ static int ath5k_eeprom_read_ants(struct ath5k_hw *ah, u32 *offset,
 	ee->ee_ant_control[mode][i++]	= (val >> 6) & 0x3f;
 	ee->ee_ant_control[mode][i++]	= val & 0x3f;
 
-	/* Get antenna modes */
-	ah->ah_antenna[mode][0] =
+	/* Get antenna switch tables */
+	ah->ah_ant_ctl[mode][AR5K_ANT_CTL] =
 	    (ee->ee_ant_control[mode][0] << 4);
-	ah->ah_antenna[mode][AR5K_ANT_FIXED_A] =
+	ah->ah_ant_ctl[mode][AR5K_ANT_SWTABLE_A] =
 	     ee->ee_ant_control[mode][1] 	|
 	    (ee->ee_ant_control[mode][2] << 6) 	|
 	    (ee->ee_ant_control[mode][3] << 12) |
 	    (ee->ee_ant_control[mode][4] << 18) |
 	    (ee->ee_ant_control[mode][5] << 24);
-	ah->ah_antenna[mode][AR5K_ANT_FIXED_B] =
+	ah->ah_ant_ctl[mode][AR5K_ANT_SWTABLE_B] =
 	     ee->ee_ant_control[mode][6] 	|
 	    (ee->ee_ant_control[mode][7] << 6) 	|
 	    (ee->ee_ant_control[mode][8] << 12) |

drivers/net/wireless/ath/ath5k/eeprom.h

@@ -240,11 +240,11 @@ enum ath5k_eeprom_freq_bands{
 #define AR5K_EEPROM_READ_HDR(_o, _v)					\
 	AR5K_EEPROM_READ(_o, ah->ah_capabilities.cap_eeprom._v);	\
 
-enum ath5k_ant_setting {
-	AR5K_ANT_VARIABLE	= 0,	/* variable by programming */
-	AR5K_ANT_FIXED_A	= 1,	/* fixed to 11a frequencies */
-	AR5K_ANT_FIXED_B	= 2,	/* fixed to 11b frequencies */
-	AR5K_ANT_MAX		= 3,
+enum ath5k_ant_table {
+	AR5K_ANT_CTL		= 0,	/* Idle switch table settings */
+	AR5K_ANT_SWTABLE_A	= 1,	/* Switch table for antenna A */
+	AR5K_ANT_SWTABLE_B	= 2,	/* Switch table for antenna B */
+	AR5K_ANT_MAX,
 };
 
 enum ath5k_ctl_mode {
@@ -461,6 +461,7 @@ struct ath5k_eeprom_info {
 	/* Spur mitigation data (fbin values for spur channels) */
 	u16	ee_spur_chans[AR5K_EEPROM_N_SPUR_CHANS][AR5K_EEPROM_N_FREQ_BANDS];
 
+	/* Antenna raw switch tables */
 	u32	ee_antenna[AR5K_EEPROM_N_MODES][AR5K_ANT_MAX];
 };