Feature/add role change cb

include/zephyr/bluetooth/conn.h

@@ -1975,6 +1975,18 @@ struct bt_conn_cb {
 
 #endif
 
+#if defined(CONFIG_BT_CLASSIC)
+	/** @brief The role of the connection has changed.
+	 *
+	 *  This callback notifies the application that the role of the
+	 *  connection has changed.
+	 *
+	 *  @param conn Connection object.
+	 *  @param status The HCI_Role_Change event's Status.
+	 */
+	void (*role_changed)(struct bt_conn *conn, uint8_t status);
+#endif
+
 	/** @internal Internally used field for list handling */
 	sys_snode_t _node;
 };

include/zephyr/bluetooth/hci_types.h

@@ -363,6 +363,7 @@ struct bt_hci_cmd_hdr {
 
 /* OpCode Group Fields */
 #define BT_OGF_LINK_CTRL                        0x01
+#define BT_OGF_LINK_POLICY                      0x02
 #define BT_OGF_BASEBAND                         0x03
 #define BT_OGF_INFO                             0x04
 #define BT_OGF_STATUS                           0x05
@@ -558,6 +559,14 @@ struct bt_hci_cp_io_capability_neg_reply {
 	uint8_t   reason;
 } __packed;
 
+#define BT_HCI_SWITCH_ROLE_CENTRAL              0
+#define BT_HCI_SWITCH_ROLE_PERIPHERAL           1
+#define BT_HCI_OP_SWITCH_ROLE                   BT_OP(BT_OGF_LINK_POLICY, 0x000b)
+struct bt_hci_cp_switch_role {
+	bt_addr_t bdaddr;
+	uint8_t   role;
+} __packed;
+
 #define BT_HCI_OP_SET_EVENT_MASK                BT_OP(BT_OGF_BASEBAND, 0x0001) /* 0x0c01 */
 struct bt_hci_cp_set_event_mask {
 	uint8_t  events[8];

subsys/bluetooth/host/classic/br.c

@@ -681,22 +681,22 @@ void bt_hci_role_change(struct net_buf *buf)
 
 	LOG_DBG("status 0x%02x role %u addr %s", evt->status, evt->role, bt_addr_str(&evt->bdaddr));
 
-	if (evt->status) {
-		return;
-	}
-
 	conn = bt_conn_lookup_addr_br(&evt->bdaddr);
 	if (!conn) {
 		LOG_ERR("Can't find conn for %s", bt_addr_str(&evt->bdaddr));
 		return;
 	}
 
-	if (evt->role) {
-		conn->role = BT_CONN_ROLE_PERIPHERAL;
-	} else {
-		conn->role = BT_CONN_ROLE_CENTRAL;
+	if (!evt->status) {
+		if (evt->role) {
+			conn->role = BT_CONN_ROLE_PERIPHERAL;
+		} else {
+			conn->role = BT_CONN_ROLE_CENTRAL;
+		}
 	}
 
+	bt_conn_role_changed(conn, evt->status);
+
 	bt_conn_unref(conn);
 }
 

subsys/bluetooth/host/classic/shell/bredr.c

@@ -6,6 +6,7 @@
 
 /*
  * Copyright (c) 2018 Intel Corporation
+ * Copyright 2025 NXP
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -989,6 +990,78 @@ static int cmd_clear(const struct shell *sh, size_t argc, char *argv[])
 	return err;
 }
 
+static const char *get_conn_role_str(uint8_t role)
+{
+	switch (role) {
+	case BT_CONN_ROLE_CENTRAL: return "central";
+	case BT_CONN_ROLE_PERIPHERAL: return "peripheral";
+	default: return "Invalid";
+	}
+}
+
+void role_changed(struct bt_conn *conn, uint8_t status)
+{
+	struct bt_conn_info info;
+	int err;
+
+	bt_shell_print("Role changed (HCI status 0x%02x)", status);
+
+	err = bt_conn_get_info(conn, &info);
+	if (err) {
+		bt_shell_print("Failed to get info");
+		return;
+	}
+
+	bt_shell_print("Role: %s", get_conn_role_str(info.role));
+}
+
+static int cmd_switch_role(const struct shell *sh, size_t argc, char *argv[])
+{
+	struct net_buf *buf = NULL;
+	struct bt_hci_cp_switch_role *cp;
+	const bt_addr_t *dest;
+	const char *action;
+	int err;
+	uint8_t role;
+
+	if (!default_conn) {
+		shell_print(sh, "Not connected");
+		return -ENOEXEC;
+	}
+
+	action = argv[1];
+
+	if (!strcmp(action, "central")) {
+		role = BT_HCI_SWITCH_ROLE_CENTRAL;
+	} else if (!strcmp(action, "peripheral")) {
+		role = BT_HCI_SWITCH_ROLE_PERIPHERAL;
+	} else {
+		shell_help(sh);
+		return SHELL_CMD_HELP_PRINTED;
+	}
+
+	dest = bt_conn_get_dst_br(default_conn);
+	if (!dest) {
+		shell_error(sh, "Failed to get br addr");
+		return -EINVAL;
+	}
+
+	buf = bt_hci_cmd_create(BT_HCI_OP_SWITCH_ROLE, sizeof(*cp));
+	if (buf != NULL) {
+		cp = net_buf_add(buf, sizeof(*cp));
+		memcpy(&cp->bdaddr, &dest->val[0], sizeof(cp->bdaddr));
+		cp->role = role;
+		err = bt_hci_cmd_send_sync(BT_HCI_OP_SWITCH_ROLE, buf, NULL);
+		if (err) {
+			shell_print(sh, "fail to send hci cmd (err %d)", err);
+		}
+	} else {
+		shell_error(sh, "hi cmd fail to create");
+	}
+
+	return 0;
+}
+
 static int cmd_default_handler(const struct shell *sh, size_t argc, char **argv)
 {
 	if (argc == 1) {
@@ -1041,6 +1114,7 @@ SHELL_STATIC_SUBCMD_SET_CREATE(br_cmds,
 	SHELL_CMD_ARG(oob, NULL, NULL, cmd_oob, 1, 0),
 	SHELL_CMD_ARG(pscan, NULL, "<value: on, off>", cmd_connectable, 2, 0),
 	SHELL_CMD_ARG(sdp-find, NULL, "<HFPAG, HFPHF>", cmd_sdp_find_record, 2, 0),
+	SHELL_CMD_ARG(switch-role, NULL, "<central, peripheral>", cmd_switch_role, 2, 0),
 	SHELL_SUBCMD_SET_END
 );
 

subsys/bluetooth/host/classic/shell/bredr.h

@@ -0,0 +1,20 @@
+/** @file
+ *  @brief Bluetooth shell functions
+ *
+ *  This is not to be included by the application.
+ */
+
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __BREDR_H
+#define __BREDR_H
+#include <stddef.h>
+#include <stdint.h>
+
+void role_changed(struct bt_conn *conn, uint8_t status);
+
+#endif /* __BREDR_H */

subsys/bluetooth/host/conn.c

@@ -1844,6 +1844,25 @@ void bt_conn_connected(struct bt_conn *conn)
 	notify_connected(conn);
 }
 
+#if defined(CONFIG_BT_CLASSIC)
+void bt_conn_role_changed(struct bt_conn *conn, uint8_t status)
+{
+	struct bt_conn_cb *callback;
+
+	SYS_SLIST_FOR_EACH_CONTAINER(&conn_cbs, callback, _node) {
+		if (callback->role_changed) {
+			callback->role_changed(conn, status);
+		}
+	}
+
+	STRUCT_SECTION_FOREACH(bt_conn_cb, cb) {
+		if (cb->role_changed) {
+			cb->role_changed(conn, status);
+		}
+	}
+}
+#endif
+
 static int conn_disconnect(struct bt_conn *conn, uint8_t reason)
 {
 	int err;

subsys/bluetooth/host/conn_internal.h

@@ -478,6 +478,10 @@ void bt_conn_set_state(struct bt_conn *conn, bt_conn_state_t state);
 
 void bt_conn_connected(struct bt_conn *conn);
 
+#if defined(CONFIG_BT_CLASSIC)
+void bt_conn_role_changed(struct bt_conn *conn, uint8_t status);
+#endif
+
 int bt_conn_le_conn_update(struct bt_conn *conn,
 			   const struct bt_le_conn_param *param);
 

subsys/bluetooth/host/shell/bt.c

@@ -54,6 +54,9 @@
 #endif /* CONFIG_BT_LL_SW_SPLIT */
 #include "host/shell/bt.h"
 #include "mesh/shell/hci.h"
+#if defined(CONFIG_BT_CLASSIC)
+#include "host/classic/shell/bredr.h"
+#endif
 
 static bool no_settings_load;
 
@@ -1182,6 +1185,9 @@ static struct bt_conn_cb conn_callbacks = {
 	.le_cs_config_complete = le_cs_config_created,
 	.le_cs_config_removed = le_cs_config_removed,
 #endif
+#if defined(CONFIG_BT_CLASSIC)
+	.role_changed = role_changed,
+#endif
 };
 #endif /* CONFIG_BT_CONN */