Mbed OS Reference | NFCController.h Source File

 /* mbed Microcontroller Library
  * Copyright (c) 2018 ARM Limited
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
 #ifndef MBED_NFC_CONTROLLER_H
 #define MBED_NFC_CONTROLLER_H
 
 #include <stdint.h>
 #include "events/EventQueue.h"
 #include "platform/SharedPtr.h"
 #include "drivers/Timer.h"
 #include "drivers/Timeout.h"
 
 #include "NFCDefinitions.h"
 #include "NFCControllerDriver.h"
 
 #include "platform/Span.h"
 
 namespace mbed {
 namespace nfc {
 
 /** @addtogroup nfc
  * @{
  */
 
 class NFCRemoteInitiator;
 class NFCRemoteTarget;
 class NFCControllerDriver;
 
 /**
  * This class represents a NFC Controller.
  *
  * A controller can be in one of three different states:
  *  * Idle/sleep state
  *  * Discovery state: The controller tries to discover a remote endpoint (initiator or target)
  *  * Connected state: The controller exchanges data with an endpoint (initiator or target)
  *
  * A NFCController instance needs to be initialized with a NFCControllerDriver instance which abstracts the specific controller being used.
  * A delegate needs to be set by the user to receive discovery events.
  */
 class NFCController : private NFCControllerDriver::Delegate {
 public:
 
     /**
      * The NFCController delegate. Users of the NFCController class need to implement this delegate's methods to receive events.
      */
     struct Delegate {
         /**
          * A enumeration of causes for the discovery process terminating.
          */
         enum nfc_discovery_terminated_reason_t {
             nfc_discovery_terminated_completed = 0, ///< Process completed, at least one endpoint was discovered
             nfc_discovery_terminated_canceled, ///< Process was canceled by the user
             nfc_discovery_terminated_rf_error ///< An unexpected error was encountered during an exchange on the air interface
         };
 
         /**
          * The discovery process terminated.
          * @param[in] reason the cause for the termination
          */
         virtual void on_discovery_terminated(nfc_discovery_terminated_reason_t reason) {}
 
         /**
          * A remote initiator was discovered (the local controller is in target mode).
          * @param[in] nfc_initiator the NFCRemoteInitiator instance
          */
         virtual void on_nfc_initiator_discovered(const SharedPtr<NFCRemoteInitiator> &nfc_initiator) {}
 
         /**
          * A remote target was discovered (the local controller is in initiator mode).
          * @param[in] nfc_target the NFCRemoteTarget instance
          */
         virtual void on_nfc_target_discovered(const SharedPtr<NFCRemoteTarget> &nfc_target) {}
 
     protected:
         ~Delegate() { }
     };
 
     /**
      * Construct a NFCController instance.
      *
      * @param[in] driver a pointer to a NFCControllerDriver instance
      * @param[in] queue a pointer to the events queue to use
      * @param[in] ndef_buffer a bytes array used to store NDEF messages
      */
     NFCController(NFCControllerDriver *driver, events::EventQueue *queue, const Span<uint8_t> &ndef_buffer);
 
     /**
      * Initialize the NFC controller
      *
      * This method must be called before any other method call.
      *
      * @return NFC_OK, or an error.
      */
     nfc_err_t initialize();
 
     /**
      * Set the delegate that will receive events generated by this controller.
      *
      * @param[in] delegate the delegate instance to use
      */
     void set_delegate(Delegate *delegate);
 
     /**
      * Get the list of RF protocols supported by this controller.
      *
      * @return a bitmask of RF protocols supported by the controller
      */
     nfc_rf_protocols_bitmask_t get_supported_rf_protocols() const;
 
     /**
      * Set the list of RF protocols to look for during discovery.
      *
      * @param[in] rf_protocols the relevant bitmask
      * @return NFC_OK on success, or
      *  NFC_ERR_UNSUPPORTED if a protocol is not supported by the controller,
      *  NFC_ERR_BUSY if the discovery process is already running
      */
     nfc_err_t configure_rf_protocols(nfc_rf_protocols_bitmask_t rf_protocols);
 
     /**
      * Start the discovery process using the protocols configured previously.
      *
      * If remote endpoints are connected when this is called, they will be disconnected.
      *
      * @return NFC_OK on success, or
      *  NFC_ERR_BUSY if the discovery process is already running
      */
     nfc_err_t start_discovery();
 
     /**
      * Cancel/stop a running discovery process.
      *
      * @return NFC_OK
      */
     nfc_err_t cancel_discovery();
 
 private:
     // These two classes need to be friends to access the following transceiver() method
     friend class NFCRemoteEndpoint;
     friend class Type4RemoteInitiator;
     nfc_transceiver_t *transceiver() const;
 
     void polling_callback(nfc_err_t ret);
 
     // NFC Stack scheduler
     void scheduler_process(bool hw_interrupt);
 
     // Callbacks from NFC stack
     static void s_polling_callback(nfc_transceiver_t *pTransceiver, nfc_err_t ret, void *pUserData);
 
     // Implementation of NFCControllerDriver::Delegate
     virtual void on_hw_interrupt();
 
     // Triggers when scheduler must be run again
     void on_timeout();
 
     NFCControllerDriver *_driver;
     events::EventQueue *_queue;
     nfc_transceiver_t *_transceiver;
     nfc_scheduler_t *_scheduler;
     Timer _timer;
     Timeout _timeout;
     Delegate *_delegate;
     bool _discovery_running;
     Span<uint8_t> _ndef_buffer;
 };
 /** @}*/
 } // namespace nfc
 } // namespace mbed
 
 #endif
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