Bluetooth: Make bt_hci_driver instances link-time constants

Declaring these as const lets the linker generate more optimal code.
Some extra care is needed with hci_ecc.c since it was overwriting the
send callback. Now the choice of send() call is done directly in the
bt_send() function

Change-Id: Iac74f5ee9bee097bbb34c11bd13d1d886700f5cc
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

drivers/bluetooth/hci/h4.c

@@ -439,7 +439,7 @@ static int h4_open(void)
 	return 0;
 }
 
-static struct bt_hci_driver drv = {
+static const struct bt_hci_driver drv = {
 	.name		= "H:4",
 	.bus		= BT_HCI_DRIVER_BUS_UART,
 	.open		= h4_open,

drivers/bluetooth/hci/h5.c

@@ -747,7 +747,7 @@ static int h5_open(void)
 	return 0;
 }
 
-static struct bt_hci_driver drv = {
+static const struct bt_hci_driver drv = {
 	.name		= "H:5",
 	.bus		= BT_HCI_DRIVER_BUS_UART,
 	.open		= h5_open,

drivers/bluetooth/hci/spi.c

@@ -338,7 +338,7 @@ static int bt_spi_open(void)
 	return 0;
 }
 
-static struct bt_hci_driver drv = {
+static const struct bt_hci_driver drv = {
 	.name		= "BT SPI",
 	.bus		= BT_HCI_DRIVER_BUS_SPI,
 	.open		= bt_spi_open,

include/drivers/bluetooth/hci_driver.h

@@ -151,7 +151,7 @@ struct bt_hci_driver {
  *
  * @return 0 on success or negative error number on failure.
  */
-int bt_hci_driver_register(struct bt_hci_driver *drv);
+int bt_hci_driver_register(const struct bt_hci_driver *drv);
 
 #ifdef __cplusplus
 }

subsys/bluetooth/controller/hci/hci_driver.c

@@ -413,7 +413,7 @@ static int hci_driver_open(void)
 	return 0;
 }
 
-static struct bt_hci_driver drv = {
+static const struct bt_hci_driver drv = {
 	.name	= "Controller",
 	.bus	= BT_HCI_DRIVER_BUS_VIRTUAL,
 	.open	= hci_driver_open,

subsys/bluetooth/host/hci_core.c

@@ -3604,6 +3604,10 @@ int bt_send(struct net_buf *buf)
 
 	bt_monitor_send(bt_monitor_opcode(buf), buf->data, buf->len);
 
+	if (IS_ENABLED(CONFIG_BLUETOOTH_TINYCRYPT_ECC)) {
+		return bt_hci_ecc_send(buf);
+	}
+
 	return bt_dev.drv->send(buf);
 }
 
@@ -3678,7 +3682,7 @@ int bt_recv_prio(struct net_buf *buf)
 	return 0;
 }
 
-int bt_hci_driver_register(struct bt_hci_driver *drv)
+int bt_hci_driver_register(const struct bt_hci_driver *drv)
 {
 	if (bt_dev.drv) {
 		return -EALREADY;
@@ -3838,7 +3842,9 @@ int bt_enable(bt_ready_cb_t cb)
 		       K_PRIO_COOP(7), 0, K_NO_WAIT);
 #endif
 
-	bt_hci_ecc_init();
+	if (IS_ENABLED(CONFIG_BLUETOOTH_TINYCRYPT_ECC)) {
+		bt_hci_ecc_init();
+	}
 
 	err = bt_dev.drv->open();
 	if (err) {

subsys/bluetooth/host/hci_core.h

@@ -129,7 +129,7 @@ struct bt_dev {
 	struct k_fifo		cmd_tx_queue;
 
 	/* Registered HCI driver */
-	struct bt_hci_driver	*drv;
+	const struct bt_hci_driver *drv;
 
 #if defined(CONFIG_BLUETOOTH_PRIVACY)
 	/* Local Identity Resolving Key */

subsys/bluetooth/host/hci_ecc.c

@@ -53,7 +53,6 @@ static const uint8_t debug_public_key[64] = {
 #endif
 
 static K_FIFO_DEFINE(ecc_queue);
-static int (*drv_send)(struct net_buf *buf);
 static uint32_t private_key[8];
 
 static void send_cmd_status(uint16_t opcode, uint8_t status)
@@ -247,7 +246,7 @@ static void clear_ecc_events(struct net_buf *buf)
 	cmd->events[1] &= ~0x01; /* LE Generate DHKey Compl Event */
 }
 
-static int ecc_send(struct net_buf *buf)
+int bt_hci_ecc_send(struct net_buf *buf)
 {
 	if (bt_buf_get_type(buf) == BT_BUF_CMD) {
 
@@ -266,7 +265,7 @@ static int ecc_send(struct net_buf *buf)
 		}
 	}
 
-	return drv_send(buf);
+	return bt_dev.drv->send(buf);
 }
 
 void bt_hci_ecc_init(void)
@@ -274,8 +273,4 @@ void bt_hci_ecc_init(void)
 	k_thread_spawn(ecc_thread_stack, sizeof(ecc_thread_stack),
 		       ecc_thread, NULL, NULL, NULL,
 		       K_PRIO_PREEMPT(10), 0, K_NO_WAIT);
-
-	/* set wrapper for driver send function */
-	drv_send = bt_dev.drv->send;
-	bt_dev.drv->send = ecc_send;
 }

subsys/bluetooth/host/hci_ecc.h

@@ -6,8 +6,5 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-#if defined(CONFIG_BLUETOOTH_TINYCRYPT_ECC)
 void bt_hci_ecc_init(void);
-#else
+int bt_hci_ecc_send(struct net_buf *buf);
-#define bt_hci_ecc_init()
-#endif /* CONFIG_BLUETOOTH_TINYCRYPT_ECC */

subsys/bluetooth/host/hci_raw.c

@@ -25,7 +25,7 @@ NET_BUF_POOL_DEFINE(hci_rx_pool, CONFIG_BLUETOOTH_RX_BUF_COUNT,
 
 struct bt_dev_raw bt_dev;
 
-int bt_hci_driver_register(struct bt_hci_driver *drv)
+int bt_hci_driver_register(const struct bt_hci_driver *drv)
 {
 	if (bt_dev.drv) {
 		return -EALREADY;
@@ -114,7 +114,7 @@ int bt_send(struct net_buf *buf)
 
 int bt_enable_raw(struct k_fifo *rx_queue)
 {
-	struct bt_hci_driver *drv = bt_dev.drv;
+	const struct bt_hci_driver *drv = bt_dev.drv;
 	int err;
 
 	BT_DBG("");
@@ -126,7 +126,9 @@ int bt_enable_raw(struct k_fifo *rx_queue)
 		return -ENODEV;
 	}
 
-	bt_hci_ecc_init();
+	if (IS_ENABLED(CONFIG_BLUETOOTH_TINYCRYPT_ECC)) {
+		bt_hci_ecc_init();
+	}
 
 	err = drv->open();
 	if (err) {

subsys/bluetooth/host/hci_raw_internal.h

@@ -12,7 +12,7 @@ extern "C" {
 
 struct bt_dev_raw {
 	/* Registered HCI driver */
-	struct bt_hci_driver	*drv;
+	const struct bt_hci_driver *drv;
 };
 
 extern struct bt_dev_raw bt_dev;

tests/bluetooth/test_bluetooth/src/bluetooth.c

@@ -29,7 +29,7 @@ static int driver_send(struct net_buf *buf)
 	return 0;
 }
 
-static struct bt_hci_driver drv = {
+static const struct bt_hci_driver drv = {
 	.name         = "test",
 	.bus          = BT_HCI_DRIVER_BUS_VIRTUAL,
 	.open         = driver_open,