Bluetooth: Controller: Implement bt_hci_driver::close

The open source controller did not expose support for shutting it down
via the close() API in the HCI driver. Add support for it, which
completes the support for disabling and enabling the Bluetooth stack in
Zephyr.

Closes #3192.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

Author: carlescufi

subsys/bluetooth/controller/hci/hci_driver.c

@@ -63,8 +63,8 @@
 
 #include "hci_internal.h"
 
-static K_SEM_DEFINE(sem_prio_recv, 0, K_SEM_MAX_LIMIT);
-static K_FIFO_DEFINE(recv_fifo);
+static struct k_sem sem_prio_recv;
+static struct k_fifo recv_fifo;
 
 struct k_thread prio_recv_thread_data;
 static K_KERNEL_STACK_DEFINE(prio_recv_thread_stack,
@@ -73,8 +73,7 @@ struct k_thread recv_thread_data;
 static K_KERNEL_STACK_DEFINE(recv_thread_stack, CONFIG_BT_RX_STACK_SIZE);
 
 #if defined(CONFIG_BT_HCI_ACL_FLOW_CONTROL)
-static struct k_poll_signal hbuf_signal =
-		K_POLL_SIGNAL_INITIALIZER(hbuf_signal);
+static struct k_poll_signal hbuf_signal;
 static sys_slist_t hbuf_pend;
 static int32_t hbuf_count;
 #endif
@@ -734,13 +733,17 @@ static int hci_driver_open(void)
 
 	DEBUG_INIT();
 
+	k_fifo_init(&recv_fifo);
+	k_sem_init(&sem_prio_recv, 0, K_SEM_MAX_LIMIT);
+
 	err = ll_init(&sem_prio_recv);
 	if (err) {
 		BT_ERR("LL initialization failed: %d", err);
 		return err;
 	}
 
 #if defined(CONFIG_BT_HCI_ACL_FLOW_CONTROL)
+	k_poll_signal_init(&hbuf_signal);
 	hci_init(&hbuf_signal);
 #else
 	hci_init(NULL);
@@ -763,11 +766,26 @@ static int hci_driver_open(void)
 	return 0;
 }
 
+static int hci_driver_close(void)
+{
+	/* Resetting the LL stops all roles */
+	ll_deinit();
+
+	/* Abort prio RX thread */
+	k_thread_abort(&prio_recv_thread_data);
+
+	/* Abort RX thread */
+	k_thread_abort(&recv_thread_data);
+
+	return 0;
+}
+
 static const struct bt_hci_driver drv = {
 	.name	= "Controller",
 	.bus	= BT_HCI_DRIVER_BUS_VIRTUAL,
 	.quirks = BT_QUIRK_NO_AUTO_DLE,
 	.open	= hci_driver_open,
+	.close	= hci_driver_close,
 	.send	= hci_driver_send,
 };