bluetooth: hci_nxp: disallow standby usage while sending HCI MSG

Sending an HCI message requires to wake up the controller
core if it's asleep. Platform controllers may send responses using
non wakeable interrupts and those can be lost during standby usage.
Blocking standby usage until the HCI message is sent.

Signed-off-by: Yassine El Aissaoui <yassine.elaissaoui@nxp.com>

Author: yeaissa

drivers/bluetooth/hci/hci_nxp.c

@@ -16,6 +16,7 @@
 #include <zephyr/drivers/flash.h>
 #include <zephyr/bluetooth/hci_types.h>
 #include <soc.h>
+#include <zephyr/pm/policy.h>
 
 #include <fwk_platform_ble.h>
 #include <fwk_platform.h>
@@ -71,6 +72,12 @@ LOG_MODULE_REGISTER(bt_driver);
 #if !defined(CONFIG_BT_HCI_SET_PUBLIC_ADDR)
 #define bt_nxp_set_mac_address(public_addr) 0
 #endif
+
+#if DT_NODE_HAS_STATUS(DT_NODELABEL(standby), okay) && defined(CONFIG_PM) &&\
+	defined(CONFIG_HCI_NXP_ENABLE_AUTO_SLEEP)
+#define HCI_NXP_LOCK_STANDBY_BEFORE_SEND
+#endif
+
 /* -------------------------------------------------------------------------- */
 /*                              Public prototypes                             */
 /* -------------------------------------------------------------------------- */
@@ -413,7 +420,18 @@ static int bt_nxp_send(const struct device *dev, struct net_buf *buf)
 	}
 
 	net_buf_push_u8(buf, packetType);
+#if defined(HCI_NXP_LOCK_STANDBY_BEFORE_SEND)
+	/* Sending an HCI message requires to wake up the controller core if it's asleep.
+	 * Platform controllers may send reponses using non wakeable interrupts which can
+	 * be lost during standby usage.
+	 * Blocking standby usage until the HCI message is sent.
+	 */
+	pm_policy_state_lock_get(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
+#endif
 	PLATFORM_SendHciMessage(buf->data, buf->len);
+#if defined(HCI_NXP_LOCK_STANDBY_BEFORE_SEND)
+	pm_policy_state_lock_put(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
+#endif
 
 	net_buf_unref(buf);