/components/nfc/t2t_lib/hal_t2t/hal_nfc_t2t.c

/* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.

 *

 * The information contained herein is property of Nordic Semiconductor ASA.

 * Terms and conditions of usage are described in detail in NORDIC

 * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.

 *

 * Licensees are granted free, non-transferable use of the information. NO

 * WARRANTY of ANY KIND is provided. This heading must NOT be removed from

 * the file.

 *

 */



#include "hal_nfc_t2t.h"

#include <stdint.h>

#include <stdbool.h>

#include "nfc_t2t_lib.h"

#include "nfc_fixes.h"

#include "nrf.h"

#include "app_util_platform.h"

#include "nordic_common.h"

#include "hal_nfc_t2t_logger.h"

#include "nrf_drv_clock.h"





// Pin for debug signals

#define HCLOCK_ON_PIN     11

#define HCLOCK_OFF_PIN    12

#define NFC_EVENT_PIN     24

#define DETECT_EVENT_PIN  25

#define TIMER4_EVENT_PIN  28



#ifdef HAL_NFC_DEBUG_PIN_ENABLE

    #include "nrf_gpio.h"

    

    #define HAL_NFC_DEBUG_PIN_CONFIG(pin_num) nrf_gpio_cfg_output(pin_num)

    #define HAL_NFC_DEBUG_PIN_CLEAR(pin_num)  nrf_gpio_pin_clear(pin_num)

    #define HAL_NFC_DEBUG_PIN_SET(pin_num)    nrf_gpio_pin_set(pin_num)

    

    

    #define HAL_NFC_DEBUG_PINS_INITIALIZE()         \

        HAL_NFC_DEBUG_PIN_CONFIG(HCLOCK_OFF_PIN);   \

        HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_OFF_PIN);    \

        HAL_NFC_DEBUG_PIN_CONFIG(HCLOCK_ON_PIN);    \

        HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_ON_PIN);     \

        HAL_NFC_DEBUG_PIN_CONFIG(NFC_EVENT_PIN);    \

        HAL_NFC_DEBUG_PIN_CLEAR(NFC_EVENT_PIN);     \

        HAL_NFC_DEBUG_PIN_CONFIG(DETECT_EVENT_PIN); \

        HAL_NFC_DEBUG_PIN_CLEAR(DETECT_EVENT_PIN);  \

        HAL_NFC_DEBUG_PIN_CONFIG(TIMER4_EVENT_PIN); \

        HAL_NFC_DEBUG_PIN_CLEAR(TIMER4_EVENT_PIN)

    

    

#else

    #define HAL_NFC_DEBUG_PIN_CLEAR(pin_num)

    #define HAL_NFC_DEBUG_PIN_SET(pin_num)

    #define HAL_NFC_DEBUG_PINS_INITIALIZE()

#endif // HAL_NFC_DEBUG_PIN_ENABLE





/* NFC library version history: 

 * #define NFC_LIB_VERSION          0x00 first experimental version intended for nRF52 IC rev. Engineering A (PCA10036, part of nRF52 Preview Development Kit)

 * #define NFC_LIB_VERSION          0x01 experimental version intended for nRF52 IC rev. Engineering B (PCA10040, part of nRF52 Development Kit)

 * #define NFC_LIB_VERSION          0x02 experimental version intended for fix IC-12826 and fix: not released HFCLK in SENSE mode

 */



#define NFC_LIB_VERSION             0x03u                                       /**< Internal: current NFC lib. version  */



#define T2T_INTERNAL_BYTES_NR       10u                                         /**< Number of internal bytes defined by Type 2 Tag Operation Technical Specification */

#define T2T_INTERNAL_BYTE_SN0_SHIFT 0u                                          /**< Internal Byte SN0, NRF_FICR->NFC.TAGHEADER0.MFGID which is Manufacturer ID */

#define T2T_INTERNAL_BYTE_SN1_SHIFT 8u                                          /**< Internal Byte SN1, NRF_FICR->NFC.TAGHEADER0.UID0 */

#define T2T_INTERNAL_BYTE_SN2_SHIFT 16u                                         /**< Internal Byte SN2, NRF_FICR->NFC.TAGHEADER0.UID1 */

#define T2T_INTERNAL_BYTE_SN3_SHIFT 0u                                          /**< Internal Byte SN3, NRF_FICR->NFC.TAGHEADER1.UID3 */

#define T2T_INTERNAL_BYTE_SN4_SHIFT 8u                                          /**< Internal Byte SN4, NRF_FICR->NFC.TAGHEADER1.UID4 */

#define T2T_INTERNAL_BYTE_SN5_SHIFT 16u                                         /**< Internal Byte SN5, NRF_FICR->NFC.TAGHEADER1.UID5 */

#define T2T_INTERNAL_BYTE_SN6_SHIFT 24u                                         /**< Internal Byte SN6, NRF_FICR->NFC.TAGHEADER1.UID6 */

#define CASCADE_TAG_BYTE            0x88u                                       /**< Constant defined by ISO/EIC 14443-3 */



#define NFCID1_2ND_LAST_BYTE2_SHIFT 16u                                         /**< Shift value for NFC ID byte 2 */

#define NFCID1_2ND_LAST_BYTE1_SHIFT 8u                                          /**< Shift value for NFC ID byte 1 */

#define NFCID1_2ND_LAST_BYTE0_SHIFT 0u                                          /**< Shift value for NFC ID byte 0 */

#define NFCID1_LAST_BYTE3_SHIFT     24u                                         /**< Shift value for NFC ID byte 3 */

#define NFCID1_LAST_BYTE2_SHIFT     16u                                         /**< Shift value for NFC ID byte 2 */

#define NFCID1_LAST_BYTE1_SHIFT     8u                                          /**< Shift value for NFC ID byte 1 */

#define NFCID1_LAST_BYTE0_SHIFT     0u                                          /**< Shift value for NFC ID byte 0 */



#define NFC_RX_BUFFER_SIZE          16u                                         /**< NFC Rx data buffer size */

#define T2T_READ_CMD                0x30u                                       /**< Type 2 Tag Read command identifier */

#define NFC_SLP_REQ_CMD             0x50u                                       /**< NFC SLP_REQ command identifier */

#define NFC_CRC_SIZE                2u                                          /**< CRC size in bytes */



#define NRF_NFCT_ERRORSTATUS_ALL    (NFCT_ERRORSTATUS_NFCFIELDTOOWEAK_Msk   | \

                                     NFCT_ERRORSTATUS_NFCFIELDTOOSTRONG_Msk | \

                                     NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk)    /**< Mask for clearing all error flags in NFCT_ERRORSTATUS register */

#define NRF_NFCT_FRAMESTATUS_RX_MSK (NFCT_FRAMESTATUS_RX_OVERRUN_Msk      | \

                                     NFCT_FRAMESTATUS_RX_PARITYSTATUS_Msk | \

                                     NFCT_FRAMESTATUS_RX_CRCERROR_Msk)          /**< Mask for clearing all flags in NFCT_FRAMESTATUS_RX register */

#define NFC_FIELD_ON_MASK            NFCT_FIELDPRESENT_LOCKDETECT_Msk           ///< Mask for checking FIELDPRESENT register for state: FIELD ON.

#define NFC_FIELD_OFF_MASK           NFCT_FIELDPRESENT_FIELDPRESENT_Msk         ///< Mask for checking FIELDPRESENT register for state: FIELD OFF.



typedef enum

{

    NFC_FIELD_STATE_NONE,           ///< Initial value indicating no NFCT Field events.

    NFC_FIELD_STATE_OFF,            ///< NFCT FIELDLOST Event has been set.

    NFC_FIELD_STATE_ON,             ///< NFCT FIELDDETECTED Event has been set.

    NFC_FIELD_STATE_UNKNOWN         ///< Both NFCT Field Events have been set - ambiguous state.

}nfct_field_sense_state_t;



#ifdef HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

/* Begin: Bugfix for FTPAN-57 (IC-9563) */

#define NRF_NFCT_SHUNTREGTHRESHOLDS  (*(uint32_t volatile *)(0x40005610))

#define NRF_NFCT_MODSTEPFIXED        (*(uint32_t volatile *)(0x40005614))

#define NRF_NFCT_MODSTEPMULTIPLIER   (*(uint32_t volatile *)(0x40005618))

#define NRF_NFCT_INITIALLOADCTRLVAL  (*(uint32_t volatile *)(0x40005688))

/* End:   Bugfix for FTPAN-57 (IC-9563) */



/* Begin: Bugfix for FTPAN-24 */

#define NRF_NFCT_AUTOCOLRESSTATUS    (*(uint32_t volatile *)(0x40005408))

/* End: Bugfix for FTPAN-24 */



/* Begin: Bugfix for FTPAN-27 */

#define NRF_NFCT_TASKS_DISABLERXDATA (*(uint32_t volatile *)(0x40005020))

/* End: Bugfix for FTPAN-27 */



/* Begin: Bugfix for FTPAN-17 */

#define NFC_HAL_FIELDPRESENT_MASK      (NFCT_FIELDPRESENT_LOCKDETECT_Msk | NFCT_FIELDPRESENT_FIELDPRESENT_Msk)



#define NFC_HAL_FIELDPRESENT_IS_LOST   ((NFCT_FIELDPRESENT_FIELDPRESENT_NoField << NFCT_FIELDPRESENT_FIELDPRESENT_Pos) \

                                       |(NFCT_FIELDPRESENT_LOCKDETECT_NotLocked << NFCT_FIELDPRESENT_LOCKDETECT_Pos))

                                     

#define NFC_HAL_FIELDPRESENT_NO_FIELD  (NFCT_FIELDPRESENT_FIELDPRESENT_NoField << NFCT_FIELDPRESENT_FIELDPRESENT_Pos)

/* End: Bugfix for FTPAN-17*/



static void hal_nfc_field_check(void);

#endif // HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND



/* Static function declarations */

static inline void nrf_nfct_event_clear(volatile uint32_t * p_event);

static inline void nrf_nfct_clock_event_handler(nrf_drv_clock_evt_type_t event);

static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state);



/* Static data */

static hal_nfc_callback             m_nfc_lib_callback = (hal_nfc_callback) NULL;                 /**< Callback to nfc_lib layer */

static void *                       m_nfc_lib_context;                                            /**< Callback execution context */

static volatile uint8_t             m_nfc_rx_buffer[NFC_RX_BUFFER_SIZE]   = {0};                  /**< Buffer for NFC Rx data */

static volatile bool                m_slp_req_received                    = false;                /**< Flag indicating that SLP_REQ Command was received */

#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

static volatile uint32_t            m_nfc_fieldpresent_mask               = NFC_FIELD_OFF_MASK;   /**< Mask used for NFC Field polling in NFCT_FIELDPRESENT register */

#endif

static volatile bool                m_field_on                            = false;                /**< Flag indicating that NFC Tag field is present */

static nrf_drv_clock_handler_item_t m_clock_handler_item;                                         /**< Clock event handler item structure */



#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

static inline void hal_nfc_re_setup(void);

static void hal_nfc_field_check(void);



#define NFC_HAL_FIELDPRESENT_MASK      (NFCT_FIELDPRESENT_LOCKDETECT_Msk | NFCT_FIELDPRESENT_FIELDPRESENT_Msk)



#define NFC_HAL_FIELDPRESENT_IS_LOST   ((NFCT_FIELDPRESENT_FIELDPRESENT_NoField << NFCT_FIELDPRESENT_FIELDPRESENT_Pos) \

                                       |(NFCT_FIELDPRESENT_LOCKDETECT_NotLocked << NFCT_FIELDPRESENT_LOCKDETECT_Pos))



#define NRF_NFCT_POWER  (*(uint32_t volatile *)(0x40005FFC))

#endif





#if defined(HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND) || defined(HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND)

static void field_timer_with_callback_config()

{

    NRF_TIMER4->MODE      = TIMER_MODE_MODE_Timer << TIMER_MODE_MODE_Pos;

    NRF_TIMER4->BITMODE   = TIMER_BITMODE_BITMODE_08Bit << TIMER_BITMODE_BITMODE_Pos;

    NRF_TIMER4->PRESCALER = 4 << TIMER_PRESCALER_PRESCALER_Pos;

    NRF_TIMER4->CC[0]     = 100 << TIMER_CC_CC_Pos;

    NRF_TIMER4->SHORTS    = TIMER_SHORTS_COMPARE0_CLEAR_Enabled << TIMER_SHORTS_COMPARE0_CLEAR_Pos;

    NRF_TIMER4->INTENSET  = TIMER_INTENSET_COMPARE0_Set << TIMER_INTENSET_COMPARE0_Pos;



    NVIC_ClearPendingIRQ(TIMER4_IRQn);

    NVIC_SetPriority(TIMER4_IRQn, APP_IRQ_PRIORITY_LOW);

    NVIC_EnableIRQ(TIMER4_IRQn);

}



void TIMER4_IRQHandler(void)

{

    HAL_NFC_DEBUG_PIN_SET(TIMER4_EVENT_PIN);

    hal_nfc_field_check();

    NRF_TIMER4->EVENTS_COMPARE[0] = 0;

    HAL_NFC_DEBUG_PIN_CLEAR(TIMER4_EVENT_PIN);

}

#endif



#ifdef HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

/* Begin: Bugfix for FTPAN-45 (IC-6915) */

volatile uint8_t m_nfc_active = 0;

/* End: Bugfix for FTPAN-45  (IC-6915) */



/* Begin: Bugfix for FTPAN-17 (IC-9563) */

/* The following three function definitions are a workaround for IC-9563: NFC in nRF52 IC rev. Engineering A does not

 * give the field lost signal when field is turned off. */

 

static   bool field_on              = false;

volatile bool hal_nfc_fielddetected = false;

volatile bool hal_nfc_fieldlost     = false;



static void hal_nfc_field_check(void)

{

    static uint32_t   field_state_cnt = 0;

    volatile uint32_t dummy;    

    uint32_t          nfc_fieldpresen_masked;



    /* Begin: Bugfix for FTPAN-24 */

    NRF_NFCT_AUTOCOLRESSTATUS = 0; /* dummy write - no effect. */

    NRF_NFCT_AUTOCOLRESSTATUS = 0; /* dummy write - no effect. */

    // Don't worry about interrupted case - NRF_NFCT->FIELDPRESENT is read each 100 us, so the workaround should succeed most of the times.

    /* End: Bugfix for FTPAN-24 */



    nfc_fieldpresen_masked = NRF_NFCT->FIELDPRESENT & NFC_HAL_FIELDPRESENT_MASK;



    if (field_on)

    {

        if (nfc_fieldpresen_masked == NFC_HAL_FIELDPRESENT_IS_LOST)

        {

            ++field_state_cnt;

            if (field_state_cnt > 7)

            {

                field_state_cnt   = 0;

                hal_nfc_fieldlost = true;

                dummy             = hal_nfc_fieldlost;

                field_on          = false;

                NVIC_SetPendingIRQ(NFCT_IRQn);

                UNUSED_VARIABLE(dummy);

            }

            

            return;

        }

    }

    else

    {     

        nfc_fieldpresen_masked &= NFCT_FIELDPRESENT_FIELDPRESENT_Msk;

        if (nfc_fieldpresen_masked !=  NFC_HAL_FIELDPRESENT_NO_FIELD)

        {

            ++field_state_cnt;

            if (field_state_cnt > 7)

            {

                field_state_cnt       = 0;

                hal_nfc_fielddetected = true;

                dummy                 = hal_nfc_fielddetected;

                field_on              = true;

                NVIC_SetPendingIRQ(NFCT_IRQn);

                UNUSED_VARIABLE(dummy);

            }

            

            return;

        }

    }



    field_state_cnt = 0;

}

/* End: Bugfix for FTPAN-17, FTPAN-27 */

#endif // HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND



/**

 * @brief Common part of setup used for NFCT initialization and reinitialization.

 */

#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

static void hal_nfc_common_hw_setup(uint8_t * const nfc_internal)

#else

static inline void hal_nfc_common_hw_setup(uint8_t * const nfc_internal)

#endif

{

    uint32_t nfc_tag_header0 = NRF_FICR->NFC.TAGHEADER0;

    uint32_t nfc_tag_header1 = NRF_FICR->NFC.TAGHEADER1;

    

/* Begin: Bugfix for FTPAN-17 */

/* fixed by avoiding usage of FIELDLOST and FIELDETECTED events */

#ifndef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

    #ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

        NRF_NFCT->INTENSET = (NFCT_INTENSET_FIELDDETECTED_Enabled << NFCT_INTENSET_FIELDDETECTED_Pos);

    #else

        NRF_NFCT->INTENSET = (NFCT_INTENSET_FIELDDETECTED_Enabled << NFCT_INTENSET_FIELDDETECTED_Pos) |

                             (NFCT_INTENSET_FIELDLOST_Enabled     << NFCT_INTENSET_FIELDLOST_Pos);

    #endif

#endif // HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

/* End: Bugfix for FTPAN-17 */



    NRF_NFCT->INTENSET = (NFCT_INTENSET_ERROR_Enabled    << NFCT_INTENSET_ERROR_Pos) |

                         (NFCT_INTENSET_SELECTED_Enabled << NFCT_INTENSET_SELECTED_Pos);



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

    /* Begin:   Bugfix for FTPAN-45 (IC-6915) */

    NRF_NFCT->INTENSET = (NFCT_INTENSET_RXFRAMESTART_Enabled << NFCT_INTENSET_RXFRAMESTART_Pos) |

                         (NFCT_INTENSET_TXFRAMESTART_Enabled << NFCT_INTENSET_TXFRAMESTART_Pos);

    /* End:   Bugfix for FTPAN-45 (IC-6915) */

#endif // HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND



    /* According to ISO/IEC 14443-3 */

    nfc_internal[0] = (uint8_t) (LSB_32(nfc_tag_header0 >> T2T_INTERNAL_BYTE_SN0_SHIFT));      //SN0

    nfc_internal[1] = (uint8_t) (LSB_32(nfc_tag_header0 >> T2T_INTERNAL_BYTE_SN1_SHIFT));      //SN1

    nfc_internal[2] = (uint8_t) (LSB_32(nfc_tag_header0 >> T2T_INTERNAL_BYTE_SN2_SHIFT));      //SN2

    nfc_internal[3] = (uint8_t) ((CASCADE_TAG_BYTE) ^ nfc_internal[0] ^ 

                                  nfc_internal[1]   ^ nfc_internal[2]);                        //BCC0 = CASCADE_TAG_BYTE ^ SN0 ^ SN1 ^ SN2

    nfc_internal[4] = (uint8_t) (LSB_32(nfc_tag_header1 >> T2T_INTERNAL_BYTE_SN3_SHIFT));      //SN3

    nfc_internal[5] = (uint8_t) (LSB_32(nfc_tag_header1 >> T2T_INTERNAL_BYTE_SN4_SHIFT));      //SN4

    nfc_internal[6] = (uint8_t) (LSB_32(nfc_tag_header1 >> T2T_INTERNAL_BYTE_SN5_SHIFT));      //SN5

    nfc_internal[7] = (uint8_t) (LSB_32(nfc_tag_header1 >> T2T_INTERNAL_BYTE_SN6_SHIFT));      //SN6

    nfc_internal[8] = (uint8_t) (nfc_internal[4] ^ nfc_internal[5] ^

                                 nfc_internal[6] ^ nfc_internal[7]);                           //BCC1 = SN3 ^ SN4 ^ SN5 ^ SN6

    nfc_internal[9] = (uint8_t) (NFC_LIB_VERSION);                                             //For internal use





    /* MSB of NFCID1_2ND_LAST register is not used - always 0 */

    NRF_NFCT->NFCID1_2ND_LAST = ((uint32_t) nfc_internal[0] << NFCID1_2ND_LAST_BYTE2_SHIFT) |

                                ((uint32_t) nfc_internal[1] << NFCID1_2ND_LAST_BYTE1_SHIFT) |

                                ((uint32_t) nfc_internal[2] << NFCID1_2ND_LAST_BYTE0_SHIFT);



    NRF_NFCT->NFCID1_LAST = ((uint32_t) nfc_internal[4] << NFCID1_LAST_BYTE3_SHIFT) |

                            ((uint32_t) nfc_internal[5] << NFCID1_LAST_BYTE2_SHIFT) |

                            ((uint32_t) nfc_internal[6] << NFCID1_LAST_BYTE1_SHIFT) |

                            ((uint32_t) nfc_internal[7] << NFCID1_LAST_BYTE0_SHIFT);



    /* Begin: Bugfix for FTPAN-25 (IC-9929) */

    /* Workaround for wrong SENSRES values require using SDD00001, but here SDD00100 is used

       because it's required to operate with Windows Phone */

    NRF_NFCT->SENSRES =

            (NFCT_SENSRES_NFCIDSIZE_NFCID1Double << NFCT_SENSRES_NFCIDSIZE_Pos) |

            (NFCT_SENSRES_BITFRAMESDD_SDD00100   << NFCT_SENSRES_BITFRAMESDD_Pos);

    /* End:   Bugfix for FTPAN-25 (IC-9929)*/

}





hal_nfc_retval hal_nfc_setup(hal_nfc_callback callback, void *cbContext)

{

    uint8_t  nfc_internal[T2T_INTERNAL_BYTES_NR];

    

    m_nfc_lib_callback = callback;

    m_nfc_lib_context  = cbContext;

    

    hal_nfc_common_hw_setup(nfc_internal);



    (void) nfcSetInternal((char *) nfc_internal, sizeof(nfc_internal));

    

    /* Initialize SDK Clock module for handling high precission clock requests */

    m_clock_handler_item.event_handler = nrf_nfct_clock_event_handler;

    m_clock_handler_item.p_next        = NULL;



    ret_code_t err_code = nrf_drv_clock_init();

    

#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND    

    /* Begin: Bugfix for FTPAN-57 (IC-9563) */

    /* Values taken from IC-9563 */

    NRF_NFCT_SHUNTREGTHRESHOLDS = 0x00000005;

    NRF_NFCT_MODSTEPFIXED       = 0x0000003F;

    NRF_NFCT_MODSTEPMULTIPLIER  = 0x00000001;

    NRF_NFCT_INITIALLOADCTRLVAL = 0x00000001;

    /* End: Bugfix for FTPAN-57  (IC-9563) */



    /* Begin: Bugfix for FTPAN-17 (IC-9563) */

    /* Activating workaround. */

    field_timer_with_callback_config();

    NRF_TIMER4->TASKS_START = 1;

    /* End:   Bugfix for FTPAN-17 (IC-9563) */

#endif // HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND



#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

    field_timer_with_callback_config();

#endif



    LOG_HAL_NFC("[NFC_HAL]: initialize\r\n");

    

    HAL_NFC_DEBUG_PINS_INITIALIZE();



    if ((err_code == NRF_SUCCESS) || (err_code == MODULE_ALREADY_INITIALIZED))

    {

        return HAL_NFC_RETVAL_OK;

    }

    else

    {

        return HAL_NFC_RETVAL_ERROR;

    }

}



/**@brief Function for clearing an event flag in NRF_NFCT registers.

 *

 * @param[in]  p_event  Pointer to event register.

 *

 */

static inline void nrf_nfct_event_clear(volatile uint32_t * p_event)

{

    *p_event = 0;



    /* Perform read to ensure clearing is effective */

    volatile uint32_t dummy = *p_event;

    (void)dummy;

}



/**@brief Function for handling events from Clock Module.

 *

 * @param[in]  event  Clock event.

 *

 */

static inline void nrf_nfct_clock_event_handler(nrf_drv_clock_evt_type_t event)

{

    switch(event)

    {

        case NRF_DRV_CLOCK_EVT_HFCLK_STARTED:

            /* Activate NFCT only when HFXO is running */

            HAL_NFC_DEBUG_PIN_SET(HCLOCK_ON_PIN);  //DEBUG!

            NRF_NFCT->TASKS_ACTIVATE = 1;

            HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_ON_PIN);  //DEBUG!

            break;



        default:

            /* No implementation required */

            break;

    }

}



#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

/**@brief Function for evaluating and handling NFC field events.

 *

 * @param[in]  field_state  Current field state.

 *

 */

static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state)

{

    if (field_state == NFC_FIELD_STATE_UNKNOWN)

    {

        /* Probe NFC field */

        uint32_t field_present = NRF_NFCT->FIELDPRESENT;



        if (field_present & m_nfc_fieldpresent_mask)

        {

            field_state = NFC_FIELD_STATE_ON;

        }

        else

        {

            field_state = NFC_FIELD_STATE_OFF;

        }

    }



    /* Field event service */

    switch(field_state)

    {

        case NFC_FIELD_STATE_ON:

            if (!m_field_on)

            {

                HAL_NFC_DEBUG_PIN_SET(HCLOCK_ON_PIN);  //DEBUG!

                nrf_drv_clock_hfclk_request(&m_clock_handler_item);

                HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_ON_PIN);  //DEBUG!

            }

            m_field_on = true;

            break;



        case NFC_FIELD_STATE_OFF:

            HAL_NFC_DEBUG_PIN_SET(HCLOCK_OFF_PIN);  //DEBUG!

            

            NRF_NFCT->TASKS_SENSE = 1;

        

        

            nrf_drv_clock_hfclk_release();



            //NRF_NFCT->TASKS_SENSE = 1;

            m_field_on = false;



            NRF_NFCT->INTENCLR = 

                (NFCT_INTENCLR_RXFRAMEEND_Clear << NFCT_INTENCLR_RXFRAMEEND_Pos) |

                (NFCT_INTENCLR_RXERROR_Clear    << NFCT_INTENCLR_RXERROR_Pos);

                

            /* Change mask to FIELD_OFF state - trigger FIELD_ON even if HW has not locked to the field */

            m_nfc_fieldpresent_mask = NFC_FIELD_OFF_MASK;



            if ((m_nfc_lib_callback != NULL) )

            {

                m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_OFF, 0, 0);

            }

            

            HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_OFF_PIN);  //DEBUG!

            break;



        default:

            /* No implementation required */

            break;

    }

}

#endif



/* This function is used by nfc_lib for unit testing only */

hal_nfc_retval hal_nfc_set_parameter(hal_nfc_param_id id, void *data, size_t dataLength)

{

    (void)id;

    (void)data;

    (void)dataLength;



    return HAL_NFC_RETVAL_OK;

} 



/* This function is used by nfc_lib for unit testing only */

hal_nfc_retval hal_nfc_get_parameter(hal_nfc_param_id id, void *data, size_t *maxDataLength)

{

    (void)id;

    (void)data;

    (void)maxDataLength;



    return HAL_NFC_RETVAL_OK;

}





hal_nfc_retval hal_nfc_start(void)

{

    NRF_NFCT->ERRORSTATUS = NRF_NFCT_ERRORSTATUS_ALL;



    NVIC_ClearPendingIRQ(NFCT_IRQn);

    NVIC_SetPriority(NFCT_IRQn, APP_IRQ_PRIORITY_LOW);

    NVIC_EnableIRQ(NFCT_IRQn);



    NRF_NFCT->TASKS_SENSE = 1;



    LOG_HAL_NFC("[NFC_HAL]: start\r\n");

    

    return HAL_NFC_RETVAL_OK;

}



hal_nfc_retval hal_nfc_send(const char *data, size_t dataLength)

{

    if (dataLength == 0)

    {

        return HAL_NFC_RETVAL_INVALID_SIZE;

    }



    /* Ignore previous TX END events, SW takes care only for data frames which tranmission is triggered in this function */

    nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);



    NRF_NFCT->PACKETPTR     = (uint32_t) data;

    NRF_NFCT->TXD.AMOUNT    = (dataLength << NFCT_TXD_AMOUNT_TXDATABYTES_Pos) &

                               NFCT_TXD_AMOUNT_TXDATABYTES_Msk;

    NRF_NFCT->INTENSET      = (NFCT_INTENSET_TXFRAMEEND_Enabled << NFCT_INTENSET_TXFRAMEEND_Pos);

    NRF_NFCT->TASKS_STARTTX = 1;



    LOG_HAL_NFC("[NFC_HAL]: send\r\n");

    

    return HAL_NFC_RETVAL_OK;

}



hal_nfc_retval hal_nfc_stop(void)

{

    NRF_NFCT->TASKS_DISABLE = 1;



    LOG_HAL_NFC("[NFC_HAL]: stop\r\n");

    

    return HAL_NFC_RETVAL_OK;

}



hal_nfc_retval hal_nfc_done(void)

{

    m_nfc_lib_callback = (hal_nfc_callback) NULL;



    return HAL_NFC_RETVAL_OK;

}



void NFCT_IRQHandler(void)

{

    nfct_field_sense_state_t current_field = NFC_FIELD_STATE_NONE;



    HAL_NFC_DEBUG_PIN_SET(NFC_EVENT_PIN);  //DEBUG!

    

#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

        /* Begin: Bugfix for FTPAN-27 */

    if (hal_nfc_fielddetected)

    {

        hal_nfc_fielddetected        = false;

        NRF_NFCT_TASKS_DISABLERXDATA = 1;

        /* End: Bugfix for FTPAN-27 */

#else

    if (NRF_NFCT->EVENTS_FIELDDETECTED && (NRF_NFCT->INTEN & NFCT_INTEN_FIELDDETECTED_Msk)) 

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_FIELDDETECTED);

#endif

        HAL_NFC_DEBUG_PIN_SET(DETECT_EVENT_PIN);  //DEBUG!

        current_field = NFC_FIELD_STATE_ON;



        LOG_HAL_NFC("[NFC_HAL]: fielddetected\r\n");

        HAL_NFC_DEBUG_PIN_CLEAR(DETECT_EVENT_PIN);  //DEBUG!

    }



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

    /* Begin: Bugfix for FTPAN-27 */

    if (hal_nfc_fieldlost)

    {

        hal_nfc_fieldlost = false;

        current_field     =

           (current_field == NFC_FIELD_STATE_NONE) ? NFC_FIELD_STATE_OFF : NFC_FIELD_STATE_UNKNOWN;



        NRF_NFCT->TASKS_SENSE = 1;



        LOG_HAL_NFC("[NFC_HAL]: fieldlost\r\n");

    }

    /* End: Bugfix for FTPAN-27 */

#elif !defined( HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND )

    if (NRF_NFCT->EVENTS_FIELDLOST && (NRF_NFCT->INTEN & NFCT_INTEN_FIELDLOST_Msk))

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_FIELDLOST);

        current_field =

           (current_field == NFC_FIELD_STATE_NONE) ? NFC_FIELD_STATE_OFF : NFC_FIELD_STATE_UNKNOWN;



        LOG_HAL_NFC("[NFC_HAL]: fieldlost\r\n");

    }

#endif



    /* Perform actions if any FIELD event is active */

    if (current_field != NFC_FIELD_STATE_NONE)

    {

       nrf_nfct_field_event_handler(current_field);

    }



    if (NRF_NFCT->EVENTS_RXFRAMEEND && (NRF_NFCT->INTEN & NFCT_INTEN_RXFRAMEEND_Msk))

    {

        /* Take into account only number of whole bytes */

        uint32_t rx_data_size = ((NRF_NFCT->RXD.AMOUNT & NFCT_RXD_AMOUNT_RXDATABYTES_Msk) >>

                                 NFCT_RXD_AMOUNT_RXDATABYTES_Pos) - NFC_CRC_SIZE;

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMEEND);



        /* Look for Tag 2 Type READ Command */

        if (m_nfc_rx_buffer[0] == T2T_READ_CMD)

        {

            if(m_nfc_lib_callback != NULL)

            {

                /* This callback should trigger transmission of READ Response */

                m_nfc_lib_callback(m_nfc_lib_context,

                                   HAL_NFC_EVENT_DATA_RECEIVED,

                                   (void*) m_nfc_rx_buffer,

                                   rx_data_size);

            }

        }

        else

        {

            /* Indicate that SLP_REQ was received - this will cause FRAMEDELAYTIMEOUT error */

            if(m_nfc_rx_buffer[0] == NFC_SLP_REQ_CMD)

            {

                m_slp_req_received = true;

            }

            /* Not a READ Command, so wait for next frame reception */

            NRF_NFCT->TASKS_ENABLERXDATA = 1;          

        }



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

        /* Begin:   Bugfix for FTPAN-45 (IC-6915) */

        m_nfc_active = 0;

        /* End:   Bugfix for FTPAN-45 (IC-69150) */

#endif

        LOG_HAL_NFC("[NFC_HAL]: rx_fend\r\n");

    }



    if (NRF_NFCT->EVENTS_TXFRAMEEND && (NRF_NFCT->INTEN & NFCT_INTEN_TXFRAMEEND_Msk))

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);



        /* Disable TX END event to ignore frame transmission other than READ response */

        NRF_NFCT->INTENCLR = (NFCT_INTENCLR_TXFRAMEEND_Clear << NFCT_INTENCLR_TXFRAMEEND_Pos);



        /* Set up for reception */

        NRF_NFCT->PACKETPTR          = (uint32_t) m_nfc_rx_buffer;

        NRF_NFCT->MAXLEN             = NFC_RX_BUFFER_SIZE;

        NRF_NFCT->TASKS_ENABLERXDATA = 1;



        if (m_nfc_lib_callback != NULL)

        {

            m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_DATA_TRANSMITTED, 0, 0);

        }



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

        /* Begin:   Bugfix for FTPAN-45 (IC-6915) */

        m_nfc_active = 0;

        /* End:   Bugfix for FTPAN-45 (IC-6915) */

#endif

        LOG_HAL_NFC("[NFC_HAL]: tx_fend\r\n");

    }



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

    /* Begin:   Bugfix for FTPAN-45 (IC-6915) */

    if (NRF_NFCT->EVENTS_RXFRAMESTART)

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMESTART);



        if (m_nfc_active == 0)

        {

            m_nfc_active = 1;

        }

        LOG_HAL_NFC("[NFC_HAL]: rx_fstart\r\n");

    }

    if (NRF_NFCT->EVENTS_TXFRAMESTART)

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMESTART);



        if (m_nfc_active == 0)

        {

            m_nfc_active = 1;

        }

        LOG_HAL_NFC("[NFC_HAL]: tx_fstart\r\n");

    }

    /* End:   Bugfix for FTPAN-45 (IC-6915) */

#endif



    if (NRF_NFCT->EVENTS_SELECTED && (NRF_NFCT->INTEN & NFCT_INTEN_SELECTED_Msk))

    {

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_SELECTED);

        /* Clear also RX END and RXERROR events because SW does not take care of commands which were received before selecting the tag */

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMEEND);

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXERROR);



        /* Set up registers for EasyDMA and start receiving packets */

        NRF_NFCT->PACKETPTR          = (uint32_t) m_nfc_rx_buffer;

        NRF_NFCT->MAXLEN             = NFC_RX_BUFFER_SIZE;

        NRF_NFCT->TASKS_ENABLERXDATA = 1;



        NRF_NFCT->INTENSET = (NFCT_INTENSET_RXFRAMEEND_Enabled << NFCT_INTENSET_RXFRAMEEND_Pos) |

                             (NFCT_INTENSET_RXERROR_Enabled    << NFCT_INTENSET_RXERROR_Pos);



        /* At this point any previous error status can be ignored */

        NRF_NFCT->FRAMESTATUS.RX = NRF_NFCT_FRAMESTATUS_RX_MSK;

        NRF_NFCT->ERRORSTATUS    = NRF_NFCT_ERRORSTATUS_ALL;



#ifndef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND

        /* Change mask to FIELD_ON state - trigger FIELD_ON only if HW has locked to the field */

        m_nfc_fieldpresent_mask = NFC_FIELD_ON_MASK;

#endif

        

        if (m_nfc_lib_callback != NULL)

        {

            m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_ON, 0, 0);

        }



        LOG_HAL_NFC("[NFC_HAL]: selected\r\n");

    }



    if (NRF_NFCT->EVENTS_RXERROR && (NRF_NFCT->INTEN & NFCT_INTEN_RXERROR_Msk))

    {

        uint32_t rx_status = NRF_NFCT->FRAMESTATUS.RX;

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXERROR);



        LOG_HAL_NFC("[NFC_HAL]: rxerror (0x%x)\r\n", (unsigned int) rx_status);

        (void) rx_status;



        /* Clear rx frame status */

        NRF_NFCT->FRAMESTATUS.RX = NRF_NFCT_FRAMESTATUS_RX_MSK;

    }



    if (NRF_NFCT->EVENTS_ERROR && (NRF_NFCT->INTEN & NFCT_INTEN_ERROR_Msk))

    {

        uint32_t err_status = NRF_NFCT->ERRORSTATUS;

        nrf_nfct_event_clear(&NRF_NFCT->EVENTS_ERROR);



        /* Clear FRAMEDELAYTIMEOUT error (expected HW behaviour) when SLP_REQ command was received */

        if ((err_status & NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk) && m_slp_req_received)

        {

            NRF_NFCT->ERRORSTATUS = NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk;

            m_slp_req_received    = false;



            LOG_HAL_NFC("[NFC_HAL]: error (SLP_REQ)\r\n");

        }

        /* Report any other error */

        err_status &= ~NFCT_ERRORSTATUS_FRAMEDELAYTIMEOUT_Msk;

        if (err_status)

        {

            LOG_HAL_NFC("[NFC_HAL]: error (0x%x)\r\n", (unsigned int) err_status);

        }



        /* Clear error status */

        NRF_NFCT->ERRORSTATUS = NRF_NFCT_ERRORSTATUS_ALL;

    }

    

    HAL_NFC_DEBUG_PIN_CLEAR(NFC_EVENT_PIN);  //DEBUG!

}





#ifdef HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND



#ifdef  HAL_NFC_ENGINEERING_A_FTPAN_WORKAROUND

    #error Wrong workaround combination

#endif



static uint32_t   field_state_cnt = 0;

/**

 * @brief Function for evaluating and handling NFC fieldlost event.

 */

static void hal_nfc_field_check(void)

{

    uint32_t nfc_fieldpresen_masked;



    nfc_fieldpresen_masked = NRF_NFCT->FIELDPRESENT & NFC_HAL_FIELDPRESENT_MASK;



    if (nfc_fieldpresen_masked == NFC_HAL_FIELDPRESENT_IS_LOST)

    {

        ++field_state_cnt;

        if (field_state_cnt > 7)

        {

            HAL_NFC_DEBUG_PIN_SET(HCLOCK_OFF_PIN);  //DEBUG!



            NRF_TIMER4->TASKS_SHUTDOWN = 1;

        

            nrf_drv_clock_hfclk_release();

            

            /* Begin:   Bugfix for FTPAN-XX (IC-XXXX) NFCT won't release HFCLK */

            // reset the NFC for release HFCLK

            __DMB();

            NRF_NFCT_POWER = 0;

            __DMB();

            NRF_NFCT_POWER = 1;

            /* END:   Bugfix for FTPAN-XX (IC-XXXX) NFCT won't release HFCLK */



            if ((m_nfc_lib_callback != NULL) )

            {

                m_nfc_lib_callback(m_nfc_lib_context, HAL_NFC_EVENT_FIELD_OFF, 0, 0);

            }

            m_field_on = false;

            

            /* Begin:   Bugfix for FTPAN-XX (IC-XXXX) NFCT won't release HFCLK */

            // resume the NFCT to initialized state

            hal_nfc_re_setup();

            /* END:   Bugfix for FTPAN-XX (IC-XXXX) NFCT won't release HFCLK */

            

            HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_OFF_PIN);  //DEBUG!

        }

        

        return;

    }



    field_state_cnt = 0;

}



/**

 * @brief Function for enablinge hight precision clock and start eveluating fieldlost event.

 */

static inline void nrf_nfct_field_event_handler(volatile nfct_field_sense_state_t field_state)

{

    if (!m_field_on)

    {

        HAL_NFC_DEBUG_PIN_SET(HCLOCK_ON_PIN);  //DEBUG!

        nrf_drv_clock_hfclk_request(&m_clock_handler_item);

        

        NRF_TIMER4->TASKS_CLEAR = 1;

        NRF_TIMER4->TASKS_START = 1;

        field_state_cnt = 0;

        

        HAL_NFC_DEBUG_PIN_CLEAR(HCLOCK_ON_PIN);  //DEBUG!

    }

    m_field_on = true;

}



/**

 * @brief Function for resume the NFCT to initialized state after software's reset.

 */

static inline void hal_nfc_re_setup(void)

{

    uint8_t  nfc_internal[T2T_INTERNAL_BYTES_NR];

    

    hal_nfc_common_hw_setup(nfc_internal);

    

    LOG_HAL_NFC("[NFC_HAL]: reinitialize\r\n");

}

#endif // HAL_NFC_ENGINEERING_BC_FTPAN_WORKAROUND