zephyr/subsys/bluetooth/host/scan.h

125 lines
4.5 KiB
C

/*
* Copyright (c) 2017-2021 Nordic Semiconductor ASA
* Copyright (c) 2015-2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef SUBSYS_BLUETOOTH_HOST_SCAN_H_
#define SUBSYS_BLUETOOTH_HOST_SCAN_H_
#include <stdint.h>
#include <zephyr/sys/atomic.h>
#include <zephyr/bluetooth/bluetooth.h>
/**
* Reasons why a scanner can be running.
* Used as input to @ref bt_le_scan_user_add
* and @ref bt_le_scan_user_remove.
*/
enum bt_le_scan_user {
/** The application explicitly instructed the stack to scan for advertisers
* using the API @ref bt_le_scan_start.
* Users of the scanner module may not use this flag as input to @ref bt_le_scan_user_add
* and @ref bt_le_scan_user_remove. Use ®ref bt_le_scan_start and @ref bt_le_scan_stop
* instead.
*/
BT_LE_SCAN_USER_EXPLICIT_SCAN,
/**
* Periodic sync syncing to a periodic advertiser.
*/
BT_LE_SCAN_USER_PER_SYNC,
/**
* Scanning to find devices to connect to.
*/
BT_LE_SCAN_USER_CONN,
/**
* Special state for a NOP for @ref bt_le_scan_user_add and @ref bt_le_scan_user_remove to
* not add/remove any user.
*/
BT_LE_SCAN_USER_NONE,
BT_LE_SCAN_USER_NUM_FLAGS,
};
void bt_scan_reset(void);
bool bt_id_scan_random_addr_check(void);
bool bt_le_scan_active_scanner_running(void);
int bt_le_scan_set_enable(uint8_t enable);
void bt_periodic_sync_disable(void);
/**
* Start / update the scanner.
*
* This API updates the users of the scanner.
* Multiple users can be enabled at the same time.
* Depending on all the users, scan parameters are selected
* and the scanner is started or updated, if needed.
* This API may update the scan parameters, for example if the scanner is already running
* when another user that demands higher duty-cycle is being added.
* It is not allowed to add a user that was already added.
*
* Every SW module that informs the scanner that it should run, needs to eventually remove
* the flag again using @ref bt_le_scan_user_remove once it does not require
* the scanner to run, anymore.
*
* If flag is set to @ref BT_LE_SCAN_USER_NONE, no user is being added. Instead, the
* existing users are checked and the scanner is started, stopped or updated.
* For platforms where scanning and initiating at the same time is not supported,
* this allows the background scanner to be started or stopped once the device starts to
* initiate a connection.
*
* @param flag user requesting the scanner
*
* @retval 0 in case of success
* @retval -EALREADY if the user is already enabled
* @retval -EPERM if the explicit scanner is being enabled while the initiator is running
* and the device does not support this configuration.
* @retval -ENOBUFS if no hci command buffer could be allocated
* @retval -EBUSY if the scanner is updated in a different thread. The user was added but
* the scanner was not started/stopped/updated.
* @returns negative error codes for errors in @ref bt_hci_cmd_send_sync
*/
int bt_le_scan_user_add(enum bt_le_scan_user flag);
/**
* Stop / update the scanner.
*
* This API updates the users of the scanner.
* Depending on all enabled users, scan parameters are selected
* and the scanner is stopped or updated, if needed.
* This API may update the scan parameters, for example if the scanner is already running
* when a user that demands higher duty-cycle is being removed.
* Removing a user that was not added does not result in an error.
*
* This API allows removing the user why the scanner is running.
* If all users for the scanner to run are removed, this API will stop the scanner.
*
* If flag is set to @ref BT_LE_SCAN_USER_NONE, no user is being added. Instead, the
* existing users are checked and the scanner is started, stopped or updated.
* For platforms where scanning and initiating at the same time is not supported,
* this allows the background scanner to be started or stopped once the device starts to
* initiate a connection.
*
* @param flag user releasing the scanner
*
* @retval 0 in case of success
* @retval -ENOBUFS if no hci command buffer could be allocated
* @retval -EBUSY if the scanner is updated in a different thread. The user was removed but
* the scanner was not started/stopped/updated.
* @returns negative error codes for errors in @ref bt_hci_cmd_send_sync
*/
int bt_le_scan_user_remove(enum bt_le_scan_user flag);
/**
* Check if the explicit scanner was enabled.
*/
bool bt_le_explicit_scanner_running(void);
#endif /* defined SUBSYS_BLUETOOTH_HOST_SCAN_H_ */