Bluetooth: controller: nRF5: Back-to-Back Radio Tx interface

Add Radio interface to perform back-to-back transmit of PDU
with a configurable inter frame spacing.

Signed-off-by: Vinayak Kariappa Chettimada <[email protected]>

Author: cvinayak

subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/radio/radio.c

@@ -446,24 +446,34 @@ void *radio_pkt_decrypt_get(void)
 #if !defined(CONFIG_BT_CTLR_TIFS_HW)
 static uint8_t sw_tifs_toggle;
 
-static void sw_switch(uint8_t dir, uint8_t phy_curr, uint8_t flags_curr, uint8_t phy_next,
-		      uint8_t flags_next)
+static void sw_switch(uint8_t dir_curr, uint8_t dir_next,
+		      uint8_t phy_curr, uint8_t flags_curr,
+		      uint8_t phy_next, uint8_t flags_next)
 {
 	uint8_t ppi = HAL_SW_SWITCH_RADIO_ENABLE_PPI(sw_tifs_toggle);
 	uint8_t cc = SW_SWITCH_TIMER_EVTS_COMP(sw_tifs_toggle);
 	uint32_t delay;
 
 	hal_radio_sw_switch_setup(cc, ppi, sw_tifs_toggle);
 
-	if (dir) {
+	if (dir_next) {
 		/* TX */
 
-		/* Calculate delay with respect to current (RX) and next
-		 * (TX) PHY. If RX PHY is LE Coded, assume S8 coding scheme.
+		/* Calculate delay with respect to current and next PHY.
+		 * If RX PHY is LE Coded, assume S8 coding scheme.
 		 */
-		delay = HAL_RADIO_NS2US_ROUND(
-		    hal_radio_tx_ready_delay_ns_get(phy_next, flags_next) +
-		    hal_radio_rx_chain_delay_ns_get(phy_curr, 1));
+		if (dir_curr) {
+			delay = HAL_RADIO_NS2US_ROUND(
+			    hal_radio_tx_ready_delay_ns_get(phy_next,
+							    flags_next) +
+			    hal_radio_tx_chain_delay_ns_get(phy_curr,
+							    flags_curr));
+		} else {
+			delay = HAL_RADIO_NS2US_ROUND(
+			    hal_radio_tx_ready_delay_ns_get(phy_next,
+							    flags_next) +
+			    hal_radio_rx_chain_delay_ns_get(phy_curr, 1));
+		}
 
 		hal_radio_txen_on_sw_switch(ppi);
 
@@ -475,7 +485,7 @@ static void sw_switch(uint8_t dir, uint8_t phy_curr, uint8_t flags_curr, uint8_t
 			HAL_SW_SWITCH_GROUP_TASK_DISABLE_PPI(
 			    sw_tifs_toggle);
 
-		if (phy_curr & PHY_CODED) {
+		if (!dir_curr && (phy_curr & PHY_CODED)) {
 			/* Switching to TX after RX on LE Coded PHY. */
 
 			uint8_t cc_s2 =
@@ -565,7 +575,7 @@ void radio_switch_complete_and_rx(uint8_t phy_rx)
 #else /* !CONFIG_BT_CTLR_TIFS_HW */
 	NRF_RADIO->SHORTS = RADIO_SHORTS_READY_START_Msk |
 			    RADIO_SHORTS_END_DISABLE_Msk;
-	sw_switch(0, 0, 0, phy_rx, 0);
+	sw_switch(1, 0, 0, 0, phy_rx, 0);
 #endif /* !CONFIG_BT_CTLR_TIFS_HW */
 }
 
@@ -579,7 +589,21 @@ void radio_switch_complete_and_tx(uint8_t phy_rx, uint8_t flags_rx, uint8_t phy_
 #else /* !CONFIG_BT_CTLR_TIFS_HW */
 	NRF_RADIO->SHORTS = RADIO_SHORTS_READY_START_Msk |
 			    RADIO_SHORTS_END_DISABLE_Msk;
-	sw_switch(1, phy_rx, flags_rx, phy_tx, flags_tx);
+	sw_switch(0, 1, phy_rx, flags_rx, phy_tx, flags_tx);
+#endif /* !CONFIG_BT_CTLR_TIFS_HW */
+}
+
+void radio_switch_complete_and_b2b_tx(uint8_t phy_curr, uint8_t flags_curr,
+				      uint8_t phy_next, uint8_t flags_next)
+{
+#if defined(CONFIG_BT_CTLR_TIFS_HW)
+	NRF_RADIO->SHORTS = RADIO_SHORTS_READY_START_Msk |
+			    RADIO_SHORTS_END_DISABLE_Msk |
+			    RADIO_SHORTS_DISABLED_TXEN_Msk;
+#else /* !CONFIG_BT_CTLR_TIFS_HW */
+	NRF_RADIO->SHORTS = RADIO_SHORTS_READY_START_Msk |
+			    RADIO_SHORTS_END_DISABLE_Msk;
+	sw_switch(1, 1, phy_curr, flags_curr, phy_next, flags_next);
 #endif /* !CONFIG_BT_CTLR_TIFS_HW */
 }
 

subsys/bluetooth/controller/ll_sw/nordic/hal/nrf5/radio/radio.h

@@ -48,6 +48,8 @@ void *radio_pkt_decrypt_get(void);
 void radio_switch_complete_and_rx(uint8_t phy_rx);
 void radio_switch_complete_and_tx(uint8_t phy_rx, uint8_t flags_rx, uint8_t phy_tx,
 				  uint8_t flags_tx);
+void radio_switch_complete_and_b2b_tx(uint8_t phy_curr, uint8_t flags_curr,
+				      uint8_t phy_next, uint8_t flags_next);
 void radio_switch_complete_and_disable(void);
 
 void radio_rssi_measure(void);