ath9k: Add Bluetooth Coexistence 3-wire support

This patch adds 3-wire bluetooth coex support for AR9285.
This support can be enabled through btcoex_enable modparam.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 274 insertions, 16 deletions

diff --git a/drivers/net/wireless/ath/ath9k/btcoex.c b/drivers/net/wireless/ath/ath9k/btcoex.c
index 9f19cd1..8fb3567 100644
--- a/drivers/net/wireless/ath/ath9k/btcoex.c
+++ b/drivers/net/wireless/ath/ath9k/btcoex.c
@@ -16,34 +16,251 @@
 
 #include "ath9k.h"
 
-void ath9k_hw_btcoex_init(struct ath_hw *ah)
+static const struct ath_btcoex_config ath_bt_config = { 0, true, true,
+			ATH_BT_COEX_MODE_SLOTTED, true, true, 2, 5, true };
+
+
+/*
+ * Detects if there is any priority bt traffic
+ */
+static void ath_detect_bt_priority(struct ath_softc *sc)
+{
+	struct ath_btcoex_info *btinfo = &sc->btcoex_info;
+
+	if (ath9k_hw_gpio_get(sc->sc_ah, btinfo->btpriority_gpio))
+		btinfo->bt_priority_cnt++;
+
+	if (time_after(jiffies, btinfo->bt_priority_time +
+			msecs_to_jiffies(ATH_BT_PRIORITY_TIME_THRESHOLD))) {
+		if (btinfo->bt_priority_cnt >= ATH_BT_CNT_THRESHOLD) {
+			DPRINTF(sc, ATH_DBG_BTCOEX,
+				"BT priority traffic detected");
+			sc->sc_flags |= SC_OP_BT_PRIORITY_DETECTED;
+		} else {
+			sc->sc_flags &= ~SC_OP_BT_PRIORITY_DETECTED;
+		}
+
+		btinfo->bt_priority_cnt = 0;
+		btinfo->bt_priority_time = jiffies;
+	}
+}
+
+/*
+ * Configures appropriate weight based on stomp type.
+ */
+static void ath_btcoex_bt_stomp(struct ath_softc *sc,
+				struct ath_btcoex_info *btinfo,
+				int stomp_type)
+{
+
+	switch (stomp_type) {
+	case ATH_BTCOEX_STOMP_ALL:
+		ath_btcoex_set_weight(btinfo, AR_BT_COEX_WGHT,
+				      AR_STOMP_ALL_WLAN_WGHT);
+		break;
+	case ATH_BTCOEX_STOMP_LOW:
+		ath_btcoex_set_weight(btinfo, AR_BT_COEX_WGHT,
+				      AR_STOMP_LOW_WLAN_WGHT);
+		break;
+	case ATH_BTCOEX_STOMP_NONE:
+		ath_btcoex_set_weight(btinfo, AR_BT_COEX_WGHT,
+				      AR_STOMP_NONE_WLAN_WGHT);
+		break;
+	default:
+		DPRINTF(sc, ATH_DBG_BTCOEX, "Invalid Stomptype\n");
+		break;
+	}
+
+	ath9k_hw_btcoex_enable(sc->sc_ah);
+}
+
+/*
+ * This is the master bt coex timer which runs for every
+ * 45ms, bt traffic will be given priority during 55% of this
+ * period while wlan gets remaining 45%
+ */
+
+static void ath_btcoex_period_timer(unsigned long data)
+{
+	struct ath_softc *sc = (struct ath_softc *) data;
+	struct ath_btcoex_info *btinfo = &sc->btcoex_info;
+	unsigned long flags;
+
+	ath_detect_bt_priority(sc);
+
+	spin_lock_irqsave(&btinfo->btcoex_lock, flags);
+
+	ath_btcoex_bt_stomp(sc, btinfo, btinfo->bt_stomp_type);
+
+	spin_unlock_irqrestore(&btinfo->btcoex_lock, flags);
+
+	if (btinfo->btcoex_period != btinfo->btcoex_no_stomp) {
+		if (btinfo->hw_timer_enabled)
+			ath_gen_timer_stop(sc->sc_ah, btinfo->no_stomp_timer);
+
+		ath_gen_timer_start(sc->sc_ah,
+			btinfo->no_stomp_timer,
+			(ath9k_hw_gettsf32(sc->sc_ah) +
+				btinfo->btcoex_no_stomp),
+				btinfo->btcoex_no_stomp * 10);
+		btinfo->hw_timer_enabled = true;
+	}
+
+	mod_timer(&btinfo->period_timer, jiffies +
+				  msecs_to_jiffies(ATH_BTCOEX_DEF_BT_PERIOD));
+}
+
+/*
+ * Generic tsf based hw timer which configures weight
+ * registers to time slice between wlan and bt traffic
+ */
+
+static void ath_btcoex_no_stomp_timer(void *arg)
+{
+	struct ath_softc *sc = (struct ath_softc *)arg;
+	struct ath_btcoex_info *btinfo = &sc->btcoex_info;
+	unsigned long flags;
+
+	DPRINTF(sc, ATH_DBG_BTCOEX, "no stomp timer running \n");
+
+	spin_lock_irqsave(&btinfo->btcoex_lock, flags);
+
+	if (btinfo->bt_stomp_type == ATH_BTCOEX_STOMP_LOW)
+		ath_btcoex_bt_stomp(sc, btinfo, ATH_BTCOEX_STOMP_NONE);
+	 else if (btinfo->bt_stomp_type == ATH_BTCOEX_STOMP_ALL)
+		ath_btcoex_bt_stomp(sc, btinfo, ATH_BTCOEX_STOMP_LOW);
+
+	spin_unlock_irqrestore(&btinfo->btcoex_lock, flags);
+}
+
+static int ath_init_btcoex_info(struct ath_hw *hw,
+				struct ath_btcoex_info *btcoex_info)
+{
+	u32 i;
+	int qnum;
+
+	qnum = ath_tx_get_qnum(hw->ah_sc, ATH9K_TX_QUEUE_DATA, ATH9K_WME_AC_BE);
+
+	btcoex_info->bt_coex_mode =
+		(btcoex_info->bt_coex_mode & AR_BT_QCU_THRESH) |
+		SM(ath_bt_config.bt_time_extend, AR_BT_TIME_EXTEND) |
+		SM(ath_bt_config.bt_txstate_extend, AR_BT_TXSTATE_EXTEND) |
+		SM(ath_bt_config.bt_txframe_extend, AR_BT_TX_FRAME_EXTEND) |
+		SM(ath_bt_config.bt_mode, AR_BT_MODE) |
+		SM(ath_bt_config.bt_quiet_collision, AR_BT_QUIET) |
+		SM(ath_bt_config.bt_rxclear_polarity, AR_BT_RX_CLEAR_POLARITY) |
+		SM(ath_bt_config.bt_priority_time, AR_BT_PRIORITY_TIME) |
+		SM(ath_bt_config.bt_first_slot_time, AR_BT_FIRST_SLOT_TIME) |
+		SM(qnum, AR_BT_QCU_THRESH);
+
+	btcoex_info->bt_coex_mode2 =
+		SM(ath_bt_config.bt_hold_rx_clear, AR_BT_HOLD_RX_CLEAR) |
+		SM(ATH_BTCOEX_BMISS_THRESH, AR_BT_BCN_MISS_THRESH) |
+		AR_BT_DISABLE_BT_ANT;
+
+	btcoex_info->bt_stomp_type = ATH_BTCOEX_STOMP_LOW;
+
+	btcoex_info->btcoex_period = ATH_BTCOEX_DEF_BT_PERIOD * 1000;
+
+	btcoex_info->btcoex_no_stomp = (100 - ATH_BTCOEX_DEF_DUTY_CYCLE) *
+		btcoex_info->btcoex_period / 100;
+
+	for (i = 0; i < 32; i++)
+		hw->hw_gen_timers.gen_timer_index[(debruijn32 << i) >> 27] = i;
+
+	setup_timer(&btcoex_info->period_timer, ath_btcoex_period_timer,
+			(unsigned long) hw->ah_sc);
+
+	btcoex_info->no_stomp_timer = ath_gen_timer_alloc(hw,
+			ath_btcoex_no_stomp_timer,
+			ath_btcoex_no_stomp_timer,
+			(void *)hw->ah_sc, AR_FIRST_NDP_TIMER);
+
+	if (btcoex_info->no_stomp_timer == NULL)
+		return -ENOMEM;
+
+	spin_lock_init(&btcoex_info->btcoex_lock);
+
+	return 0;
+}
+
+int ath9k_hw_btcoex_init(struct ath_hw *ah)
 {
 	struct ath_btcoex_info *btcoex_info = &ah->ah_sc->btcoex_info;
+	int ret = 0;
+
+	if (btcoex_info->btcoex_scheme == ATH_BTCOEX_CFG_2WIRE) {
+		/* connect bt_active to baseband */
+		REG_CLR_BIT(ah, AR_GPIO_INPUT_EN_VAL,
+				(AR_GPIO_INPUT_EN_VAL_BT_PRIORITY_DEF |
+				 AR_GPIO_INPUT_EN_VAL_BT_FREQUENCY_DEF));
+
+		REG_SET_BIT(ah, AR_GPIO_INPUT_EN_VAL,
+				AR_GPIO_INPUT_EN_VAL_BT_ACTIVE_BB);
+
+		/* Set input mux for bt_active to gpio pin */
+		REG_RMW_FIELD(ah, AR_GPIO_INPUT_MUX1,
+				AR_GPIO_INPUT_MUX1_BT_ACTIVE,
+				btcoex_info->btactive_gpio);
 
-	/* connect bt_active to baseband */
-	REG_CLR_BIT(ah, AR_GPIO_INPUT_EN_VAL,
-			(AR_GPIO_INPUT_EN_VAL_BT_PRIORITY_DEF |
-			 AR_GPIO_INPUT_EN_VAL_BT_FREQUENCY_DEF));
+		/* Configure the desired gpio port for input */
+		ath9k_hw_cfg_gpio_input(ah, btcoex_info->btactive_gpio);
+	} else {
+		/* btcoex 3-wire */
+		REG_SET_BIT(ah, AR_GPIO_INPUT_EN_VAL,
+				(AR_GPIO_INPUT_EN_VAL_BT_PRIORITY_BB |
+				 AR_GPIO_INPUT_EN_VAL_BT_ACTIVE_BB));
 
-	REG_SET_BIT(ah, AR_GPIO_INPUT_EN_VAL,
-			AR_GPIO_INPUT_EN_VAL_BT_ACTIVE_BB);
+		/* Set input mux for bt_prority_async and
+		 *                  bt_active_async to GPIO pins */
+		REG_RMW_FIELD(ah, AR_GPIO_INPUT_MUX1,
+				AR_GPIO_INPUT_MUX1_BT_ACTIVE,
+				btcoex_info->btactive_gpio);
 
-	/* Set input mux for bt_active to gpio pin */
-	REG_RMW_FIELD(ah, AR_GPIO_INPUT_MUX1,
-			AR_GPIO_INPUT_MUX1_BT_ACTIVE,
-			btcoex_info->btactive_gpio);
+		REG_RMW_FIELD(ah, AR_GPIO_INPUT_MUX1,
+				AR_GPIO_INPUT_MUX1_BT_PRIORITY,
+				btcoex_info->btpriority_gpio);
 
-	/* Configure the desired gpio port for input */
-	ath9k_hw_cfg_gpio_input(ah, btcoex_info->btactive_gpio);
+		/* Configure the desired GPIO ports for input */
+
+		ath9k_hw_cfg_gpio_input(ah, btcoex_info->btactive_gpio);
+		ath9k_hw_cfg_gpio_input(ah, btcoex_info->btpriority_gpio);
+
+		ret = ath_init_btcoex_info(ah, btcoex_info);
+	}
+
+	return ret;
 }
 
 void ath9k_hw_btcoex_enable(struct ath_hw *ah)
 {
 	struct ath_btcoex_info *btcoex_info = &ah->ah_sc->btcoex_info;
 
-	/* Configure the desired GPIO port for TX_FRAME output */
-	ath9k_hw_cfg_output(ah, btcoex_info->wlanactive_gpio,
-			    AR_GPIO_OUTPUT_MUX_AS_TX_FRAME);
+	if (btcoex_info->btcoex_scheme == ATH_BTCOEX_CFG_2WIRE) {
+		/* Configure the desired GPIO port for TX_FRAME output */
+		ath9k_hw_cfg_output(ah, btcoex_info->wlanactive_gpio,
+				AR_GPIO_OUTPUT_MUX_AS_TX_FRAME);
+	} else {
+		/*
+		 * Program coex mode and weight registers to
+		 * enable coex 3-wire
+		 */
+		REG_WRITE(ah, AR_BT_COEX_MODE, btcoex_info->bt_coex_mode);
+		REG_WRITE(ah, AR_BT_COEX_WEIGHT, btcoex_info->bt_coex_weights);
+		REG_WRITE(ah, AR_BT_COEX_MODE2, btcoex_info->bt_coex_mode2);
+
+		REG_RMW_FIELD(ah, AR_QUIET1,
+				AR_QUIET1_QUIET_ACK_CTS_ENABLE, 1);
+		REG_RMW_FIELD(ah, AR_PCU_MISC,
+				AR_PCU_BT_ANT_PREVENT_RX, 0);
+
+		ath9k_hw_cfg_output(ah, btcoex_info->wlanactive_gpio,
+				AR_GPIO_OUTPUT_MUX_AS_RX_CLEAR_EXTERNAL);
+	}
+
+	REG_RMW(ah, AR_GPIO_PDPU,
+		(0x2 << (btcoex_info->btactive_gpio * 2)),
+		(0x3 << (btcoex_info->btactive_gpio * 2)));
 
 	ah->ah_sc->sc_flags |= SC_OP_BTCOEX_ENABLED;
 }
@@ -57,5 +274,46 @@ void ath9k_hw_btcoex_disable(struct ath_hw *ah)
 	ath9k_hw_cfg_output(ah, btcoex_info->wlanactive_gpio,
 			AR_GPIO_OUTPUT_MUX_AS_OUTPUT);
 
+	if (btcoex_info->btcoex_scheme == ATH_BTCOEX_CFG_3WIRE) {
+		REG_WRITE(ah, AR_BT_COEX_MODE, AR_BT_QUIET | AR_BT_MODE);
+		REG_WRITE(ah, AR_BT_COEX_WEIGHT, 0);
+		REG_WRITE(ah, AR_BT_COEX_MODE2, 0);
+	}
+
 	ah->ah_sc->sc_flags &= ~SC_OP_BTCOEX_ENABLED;
 }
+
+/*
+ * Pause btcoex timer and bt duty cycle timer
+ */
+void ath_btcoex_timer_pause(struct ath_softc *sc,
+			    struct ath_btcoex_info *btinfo)
+{
+
+	del_timer_sync(&btinfo->period_timer);
+
+	if (btinfo->hw_timer_enabled)
+		ath_gen_timer_stop(sc->sc_ah, btinfo->no_stomp_timer);
+
+	btinfo->hw_timer_enabled = false;
+}
+
+/*
+ * (Re)start btcoex timers
+ */
+void ath_btcoex_timer_resume(struct ath_softc *sc,
+			     struct ath_btcoex_info *btinfo)
+{
+
+	DPRINTF(sc, ATH_DBG_BTCOEX, "Starting btcoex timers");
+
+	/* make sure duty cycle timer is also stopped when resuming */
+	if (btinfo->hw_timer_enabled)
+		ath_gen_timer_stop(sc->sc_ah, btinfo->no_stomp_timer);
+
+	btinfo->bt_priority_cnt = 0;
+	btinfo->bt_priority_time = jiffies;
+	sc->sc_flags &= ~SC_OP_BT_PRIORITY_DETECTED;
+
+	mod_timer(&btinfo->period_timer, jiffies);
+}