prepare v5.0.0, revert firmware interfacing changes

linux/ipcore/PapbVcInterface.h

@@ -30,7 +30,8 @@ class PapbVcInterface : public VirtualChannelIF {
    * @param uioFile       UIO file providing access to the PAPB bus
    * @param mapNum        Map number of UIO map associated with this virtual channel
    */
-  PapbVcInterface(LinuxLibgpioIF* gpioComIF, gpioId_t papbEmptyId, std::string uioFile, int mapNum);
+  PapbVcInterface(LinuxLibgpioIF* gpioComIF, gpioId_t papbBusyId, gpioId_t papbEmptyId,
+                  std::string uioFile, int mapNum);
   virtual ~PapbVcInterface();
 
   bool isBusy() const override;
@@ -82,6 +83,9 @@ class PapbVcInterface : public VirtualChannelIF {
   static constexpr long int MAX_DELAY_PAPB_POLLING_NS = 40;
 
   LinuxLibgpioIF* gpioComIF = nullptr;
+
+  /** Pulled to low when virtual channel not ready to receive data */
+  gpioId_t papbBusyId = gpio::NO_GPIO;
   /** High when external buffer memory of virtual channel is empty */
   gpioId_t papbEmptyId = gpio::NO_GPIO;
 
@@ -116,13 +120,13 @@ class PapbVcInterface : public VirtualChannelIF {
    *
    * @return  returnvalue::OK when ready to receive data else PAPB_BUSY.
    */
-  inline bool pollReadyForPacket() const;
+  inline ReturnValue_t pollInterfaceReadiness(uint32_t maxPollRetries, bool checkReadyState) const;
 
   /**
    * @brief   This function can be used for debugging to check whether there are packets in
    *          the packet buffer of the virtual channel or not.
    */
-  bool isVcInterfaceBufferEmpty();
+  void isVcInterfaceBufferEmpty();
 
   /**
    * @brief   This function sends a complete telemetry transfer frame data field (1105 bytes)