NFCEEPROM.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2018 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef MBED_NFC_EEPROM_H
00018 #define MBED_NFC_EEPROM_H
00019 
00020 #include <stdint.h>
00021 #include "events/EventQueue.h"
00022 
00023 #include "NFCDefinitions.h"
00024 #include "NFCTarget.h"
00025 #include "NFCEEPROMDriver.h"
00026 
00027 namespace mbed {
00028 namespace nfc {
00029 
00030 /**
00031  * @addtogroup nfc
00032  * @{
00033  */
00034 
00035 /**
00036  * The NFC EEPROM class represents a NFC target device connected using a wired
00037  * link (I2C, SPI, etc).
00038  *
00039  * These EEPROMs essentially provide addressable memory that can be accessed
00040  * using either a wired or NFC interface.
00041  *
00042  * In NFC mode these most often conform to one of the NFC tag types defined
00043  * by the NFC Forum, therefore encoding NDEF data in these EEPROMs will
00044  * ensure that it is understandable by a NFC reader.
00045  */
00046 class NFCEEPROM : public NFCTarget, public NFCEEPROMDriver::Delegate {
00047 public:
00048     /**
00049      * Construct a NFCEEPROM instance.
00050      *
00051      * @param[in] driver a pointer to a NFCEEPROMDriver instance
00052      * @param[in] queue a pointer to the events queue to use
00053      * @param[in] ndef_buffer a bytes array used to store NDEF messages
00054      */
00055     NFCEEPROM(NFCEEPROMDriver *driver, events::EventQueue *queue, const Span<uint8_t>  &ndef_buffer);
00056 
00057     /**
00058      * The NFCEEPROM delegate. Users of the NFCEEPROM class need to implement this delegate's methods to receive events.
00059      */
00060     struct Delegate : NFCTarget::Delegate {
00061         /**
00062          * The NDEF message erasing request completed.
00063          *
00064          * @param[in] result NFC_OK or an error code on failure
00065          */
00066         virtual void on_ndef_message_erased(nfc_err_t result) {}
00067 
00068         /**
00069          * The NDEF message writing request completed.
00070          *
00071          * @param[in] result NFC_OK or an error code on failure
00072          */
00073         virtual void on_ndef_message_written(nfc_err_t result) {}
00074 
00075         /**
00076          * The NDEF message reading request completed.
00077          *
00078          * @param[in] result NFC_OK or an error code on failure
00079          */
00080         virtual void on_ndef_message_read(nfc_err_t result) {}
00081 
00082     protected:
00083         ~Delegate() {}
00084     };
00085 
00086     /**
00087      * Initialize the NFC EEPROM
00088      *
00089      * This method must be called before any other method call.
00090      *
00091      * @return NFC_OK, or an error.
00092      */
00093     nfc_err_t initialize();
00094 
00095     /**
00096      * Set the delegate that will receive events generated by this EEPROM.
00097      *
00098      * @param[in] delegate the delegate instance to use
00099      */
00100     void set_delegate(Delegate *delegate);
00101 
00102     // Implementation of NFCTarget
00103     virtual void write_ndef_message();
00104     virtual void read_ndef_message();
00105     virtual void erase_ndef_message();
00106 
00107 private:
00108     // Implementation of NFCEEPROMDriver::Delegate
00109     virtual void on_session_started(bool success);
00110     virtual void on_session_ended(bool success);
00111     virtual void on_bytes_read(size_t count);
00112     virtual void on_bytes_written(size_t count);
00113     virtual void on_size_written(bool success);
00114     virtual void on_size_read(bool success, size_t size);
00115     virtual void on_bytes_erased(size_t count);
00116 
00117     void handle_error(nfc_err_t ret);
00118     void continue_write();
00119     void continue_read();
00120     void continue_erase();
00121 
00122     // NFCNDEFCapable implementation
00123     virtual NFCNDEFCapable::Delegate *ndef_capable_delegate();
00124 
00125     enum nfc_eeprom_operation_t {
00126         nfc_eeprom_idle,
00127 
00128         nfc_eeprom_write_start_session,
00129         nfc_eeprom_write_write_bytes,
00130         nfc_eeprom_write_write_size,
00131         nfc_eeprom_write_end_session,
00132 
00133         nfc_eeprom_read_start_session,
00134         nfc_eeprom_read_read_size,
00135         nfc_eeprom_read_read_bytes,
00136         nfc_eeprom_read_end_session,
00137 
00138         nfc_eeprom_erase_start_session,
00139         nfc_eeprom_erase_write_max_size,
00140         nfc_eeprom_erase_erase_bytes,
00141         nfc_eeprom_erase_write_0_size,
00142         nfc_eeprom_erase_end_session
00143     };
00144 
00145     Delegate *_delegate;
00146     NFCEEPROMDriver *_driver;
00147     bool _initialized;
00148 
00149     nfc_eeprom_operation_t _current_op;
00150     ac_buffer_t _ndef_buffer_reader;
00151     size_t _ndef_buffer_read_sz;
00152     uint32_t _eeprom_address;
00153     nfc_err_t _operation_result;
00154 };
00155 
00156 /**
00157  * @}
00158  */
00159 
00160 
00161 } // namespace nfc
00162 } // namespace mbed
00163 
00164 #endif