text: /* mbed Microcontroller Library
   * Copyright (c) 2006-2013 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 __NRF5x_GAP_H__
  #define __NRF5x_GAP_H__
  
  #ifdef YOTTA_CFG_MBED_OS
      #include "mbed-drivers/mbed.h"
  #else
      #include "mbed.h"
  #endif
  #ifndef YOTTA_CFG_WHITELIST_MAX_SIZE
      #define YOTTA_CFG_WHITELIST_MAX_SIZE BLE_GAP_WHITELIST_ADDR_MAX_COUNT
  #elif YOTTA_CFG_WHITELIST_MAX_SIZE > BLE_GAP_WHITELIST_ADDR_MAX_COUNT
      #undef YOTTA_CFG_WHITELIST_MAX_SIZE
      #define YOTTA_CFG_WHITELIST_MAX_SIZE BLE_GAP_WHITELIST_ADDR_MAX_COUNT
  #endif
  #ifndef YOTTA_CFG_IRK_TABLE_MAX_SIZE
      #define YOTTA_CFG_IRK_TABLE_MAX_SIZE BLE_GAP_WHITELIST_IRK_MAX_COUNT
  #elif YOTTA_CFG_IRK_TABLE_MAX_SIZE > BLE_GAP_WHITELIST_IRK_MAX_COUNT
      #undef YOTTA_CFG_IRK_TABLE_MAX_SIZE
      #define YOTTA_CFG_IRK_TABLE_MAX_SIZE BLE_GAP_WHITELIST_IRK_MAX_COUNT
  #endif
  #include "ble/blecommon.h"
  #include "nrf_ble.h"
  #include "ble/GapAdvertisingParams.h"
  #include "ble/GapAdvertisingData.h"
  #include "ble/Gap.h"
  #include "ble/GapScanningParams.h"
  
  #include "nrf_soc.h"
  
  extern "C" {
  #include "ble_radio_notification.h"
  #include "app_util_platform.h"
  }
  
  #include "btle_security.h"
  
  void radioNotificationStaticCallback(bool param);
  
  /**************************************************************************/
  /*!
      \brief
  
  */
  /**************************************************************************/
  class nRF5xGap : public Gap
  {
  public:
      /* Functions that must be implemented from Gap */
      virtual ble_error_t setAddress(AddressType_t  type,  const Address_t address);
      virtual ble_error_t getAddress(AddressType_t *typeP, Address_t address);
      virtual ble_error_t setAdvertisingData(const GapAdvertisingData &, const GapAdvertisingData &);
  
      virtual uint16_t    getMinAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_INTERVAL_MIN);}
      virtual uint16_t    getMinNonConnectableAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_NONCON_INTERVAL_MIN);}
      virtual uint16_t    getMaxAdvertisingInterval(void) const {return GapAdvertisingParams::ADVERTISEMENT_DURATION_UNITS_TO_MS(BLE_GAP_ADV_INTERVAL_MAX);}
  
      virtual ble_error_t startAdvertising(const GapAdvertisingParams &);
      virtual ble_error_t stopAdvertising(void);
      virtual ble_error_t connect(const Address_t, BLEProtocol::AddressType_t peerAddrType, const ConnectionParams_t *connectionParams, const GapScanningParams *scanParams);
      virtual ble_error_t disconnect(Handle_t connectionHandle, DisconnectionReason_t reason);
      virtual ble_error_t disconnect(DisconnectionReason_t reason);
  
      virtual ble_error_t setDeviceName(const uint8_t *deviceName);
      virtual ble_error_t getDeviceName(uint8_t *deviceName, unsigned *lengthP);
      virtual ble_error_t setAppearance(GapAdvertisingData::Appearance appearance);
      virtual ble_error_t getAppearance(GapAdvertisingData::Appearance *appearanceP);
  
      virtual ble_error_t setTxPower(int8_t txPower);
      virtual void        getPermittedTxPowerValues(const int8_t **valueArrayPP, size_t *countP);
  
      void     setConnectionHandle(uint16_t con_handle);
      uint16_t getConnectionHandle(void);
  
      virtual ble_error_t getPreferredConnectionParams(ConnectionParams_t *params);
      virtual ble_error_t setPreferredConnectionParams(const ConnectionParams_t *params);
      virtual ble_error_t updateConnectionParams(Handle_t handle, const ConnectionParams_t *params);
  
      virtual ble_error_t reset(void);
  
      /*
       * The following functions are part of the whitelisting experimental API.
       * Therefore, this functionality can change in the near future.
       */
      virtual uint8_t getMaxWhitelistSize(void) const;
      virtual ble_error_t getWhitelist(Gap::Whitelist_t &whitelistOut) const;
      virtual ble_error_t setWhitelist(const Gap::Whitelist_t &whitelistIn);
  
      virtual ble_error_t setAdvertisingPolicyMode(AdvertisingPolicyMode_t mode);
      virtual ble_error_t setScanningPolicyMode(ScanningPolicyMode_t mode);
      virtual ble_error_t setInitiatorPolicyMode(InitiatorPolicyMode_t mode);
      virtual Gap::AdvertisingPolicyMode_t getAdvertisingPolicyMode(void) const;
      virtual Gap::ScanningPolicyMode_t getScanningPolicyMode(void) const;
      virtual Gap::InitiatorPolicyMode_t getInitiatorPolicyMode(void) const;
  
      virtual ble_error_t initRadioNotification(void) {
          if (ble_radio_notification_init(APP_IRQ_PRIORITY_HIGH /*MID*/, NRF_RADIO_NOTIFICATION_DISTANCE_800US, radioNotificationStaticCallback) == NRF_SUCCESS) {
              return BLE_ERROR_NONE;
          }
  
          return BLE_ERROR_UNSPECIFIED;
      }
  
  /* Observer role is not supported by S110, return BLE_ERROR_NOT_IMPLEMENTED */
  #if !defined(TARGET_MCU_NRF51_16K_S110) && !defined(TARGET_MCU_NRF51_32K_S110)
      virtual ble_error_t startRadioScan(const GapScanningParams &scanningParams);
      virtual ble_error_t stopScan(void);
  #endif
  
  private:
      /*
       * Whitelisting API related structures and helper functions.
       */
  
      /* Policy modes set by the user. By default these are set to ignore the whitelist */
      Gap::AdvertisingPolicyMode_t advertisingPolicyMode;
      Gap::ScanningPolicyMode_t    scanningPolicyMode;
  
      /* Internal representation of a whitelist */
      uint8_t         whitelistAddressesSize;
      ble_gap_addr_t  whitelistAddresses[YOTTA_CFG_WHITELIST_MAX_SIZE];
  
      /*
       * An internal function used to populate the ble_gap_whitelist_t that will be used by
       * the SoftDevice for filtering requests. This function is needed because for the BLE
       * API the whitelist is just a collection of keys, but for the stack it also includes
       * the IRK table.
       */
      ble_error_t generateStackWhitelist(ble_gap_whitelist_t &whitelist);
  
  private:
      bool    radioNotificationCallbackParam; /* parameter to be passed into the Timeout-generated radio notification callback. */
      Timeout radioNotificationTimeout;
  
      /*
       * A helper function to post radio notification callbacks with low interrupt priority.
       */
      void postRadioNotificationCallback(void) {
  #ifdef YOTTA_CFG_MBED_OS
          /*
           * In mbed OS, all user-facing BLE events (interrupts) are posted to the
           * MINAR scheduler to be executed as callbacks in thread mode. MINAR guards
           * its critical sections from interrupts by acquiring CriticalSectionLock,
           * which results in a call to sd_nvic_critical_region_enter(). Thus, it is
           * safe to invoke MINAR APIs from interrupt context as long as those
           * interrupts are blocked by sd_nvic_critical_region_enter().
           *
           * Radio notifications are a special case for the above. The Radio
           * Notification IRQ is handled at a very high priority--higher than the
           * level blocked by sd_nvic_critical_region_enter(). Thus Radio Notification
           * events can preempt MINAR's critical sections. Using MINAR APIs (such as
           * posting an event) directly in processRadioNotification() may result in a
           * race condition ending in a hard-fault.
           *
           * The solution is to *not* call MINAR APIs directly from the Radio
           * Notification handling; i.e. to do the bulk of RadioNotification
           * processing at a reduced priority which respects MINAR's critical
           * sections. Unfortunately, on a cortex-M0, there is no clean way to demote
           * priority for the currently executing interrupt--we wouldn't want to
           * demote the radio notification handling anyway because it is sensitive to
           * timing, and the system expects to finish this handling very quickly. The
           * workaround is to employ a Timeout to trigger
           * postRadioNotificationCallback() after a very short delay (~0 us) and post
           * the MINAR callback that context.
           *
           * !!!WARNING!!! Radio notifications are very time critical events. The
           * current solution is expected to work under the assumption that
           * postRadioNotificationCalback() will be executed BEFORE the next radio
           * notification event is generated.
           */
          minar::Scheduler::postCallback(
              mbed::util::FunctionPointer1<void, bool>(&radioNotificationCallback, &FunctionPointerWithContext<bool>::call).bind(radioNotificationCallbackParam)
          );
  #else
          /*
           * In mbed classic, all user-facing BLE events execute callbacks in interrupt
           * mode. Radio Notifications are a special case because its IRQ is handled at
           * a very high priority. Thus Radio Notification events can preempt other
           * operations that require interaction with the SoftDevice such as advertising
           * payload updates and changing the Gap state. Therefore, executing a Radio
           * Notification callback directly from processRadioNotification() may result
           * in a race condition ending in a hard-fault.
           *
           * The solution is to *not* execute the Radio Notification callback directly
           * from the Radio Notification handling; i.e. to do the bulk of the
           * Radio Notification processing at a reduced priority. Unfortunately, on a
           * cortex-M0, there is no clean way to demote priority for the currently
           * executing interrupt--we wouldn't want to demote the radio notification
           * handling anyway because it is sensitive to timing, and the system expects
           * to finish this handling very quickly. The workaround is to employ a Timeout
           * to trigger postRadioNotificationCallback() after a very short delay (~0 us)
           * and execute the callback in that context.
           *
           * !!!WARNING!!! Radio notifications are very time critical events. The
           * current solution is expected to work under the assumption that
           * postRadioNotificationCalback() will be executed BEFORE the next radio
           * notification event is generated.
           */
          radioNotificationCallback.call(radioNotificationCallbackParam);
  #endif /* #ifdef YOTTA_CFG_MBED_OS */
      }
  
      /**
       * A helper function to process radio-notification events; to be called internally.
       * @param param [description]
       */
      void processRadioNotificationEvent(bool param) {
          radioNotificationCallbackParam = param;
          radioNotificationTimeout.attach_us(mbed::callback(this, &nRF5xGap::postRadioNotificationCallback), 0);
      }
      friend void radioNotificationStaticCallback(bool param); /* allow invocations of processRadioNotificationEvent() */
  
  private:
      uint16_t m_connectionHandle;
  
      /*
       * Allow instantiation from nRF5xn when required.
       */
      friend class nRF5xn;
  
      nRF5xGap() :
          advertisingPolicyMode(Gap::ADV_POLICY_IGNORE_WHITELIST),
          scanningPolicyMode(Gap::SCAN_POLICY_IGNORE_WHITELIST),
          whitelistAddressesSize(0) {
          m_connectionHandle = BLE_CONN_HANDLE_INVALID;
      }
  
      nRF5xGap(nRF5xGap const &);
      void operator=(nRF5xGap const &);
  };
  
  #endif // ifndef __NRF5x_GAP_H__
  