// ******************************************************************************
//
// Copyright:
//     (c) Mustangpeak, 2013.
//
//     The contents of this file are subject to the GNU GPL v3 licence/ you maynot use
//     this file except in compliance with the License. You may obtain a copy of the
//     License at http://www.gnu.org/licenses/gpl.html
//
// * Revision History:
//     2013-03-29:   Created
//
// * Description:
//    Common Service Mode functions
//
// ******************************************************************************

unit CommonServiceMode;

{$I Options.inc}

uses
  NMRAnetDCC,
  ServiceModeDefines;
  
type
  TServiceModePtr = procedure(BufferPtr: PDCCBufferInfo);
  PServiceModePtr = ^TServiceModePtr;

  
  procedure CommonServiceMode_DirectLoadTransmitter(BufferPtr: PDCCBufferInfo; RegisterOffset, ReadWrite, DataByte: Byte);     // Valid for Paged, Register, Address Modes Only
  procedure CommonServiceMode_DirectLoadTransmitterDirectMode(BufferPtr: PDCCBufferInfo; CV_Address: Word; InstructionCode, DataByte: Byte);
  procedure CommonServiceMode_DirectLoadTransmitterPagePreset(BufferPtr: PDCCBufferInfo);
  procedure CommonServiceMode_PowerOnCycle(BufferPtr: PDCCBufferInfo; InstructionCount, NextState: Word);
  procedure CommonServiceMode_ResetCycle(BufferPtr: PDCCBufferInfo; InstructionPtr: PServiceModePtr; PacketCount: Word; NextState: Word; PrepareForAck: Boolean);
  procedure CommonServiceMode_SendInstructions(BufferPtr: PDCCBufferInfo; SendInstruction, AckHandler, NoAckHandler: PServiceModePtr; InstructionCount: Word);
  procedure CommonServiceMode_NoAckHandler(BufferPtr: PDCCBufferInfo);
  procedure CommonServiceMode_AckHandlerByte(BufferPtr: PDCCBufferInfo);
  procedure CommonServiceMode_ResultReady(BufferPtr: PDCCBufferInfo);

implementation

procedure ResetACK;
begin
  ServiceModeInfo.State.PROGRAMMING_ACK_SCANNING_FOR_ACK_BIT := 1;            // Start Looking
  ServiceModeInfo.State.PROGRAMMING_ACK_DETECTED_BIT := 0;
  ServiceModeInfo.State.PROGRAMMING_ACK_TIMER_DETECTED_LEADINGEDGE_BIT := 0;
  ServiceModeInfo.State.PROGRAMMING_ACK_FAILED_TO_DETECT_TRAILINGEDGE_BIT := 0;
end;

// ***************************************************************************
//  procedure CommonServiceMode_AckHandlerByte
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_AckHandlerByte(BufferPtr: PDCCBufferInfo);
begin
  case ServiceModeInfo.ServiceModeType of
    SERVICE_MODE_TYPE_DIRECT_BYTE       : ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_RESPONSE_DIRECT_BYTE_MODE;
    SERVICE_MODE_TYPE_DIRECT_BIT        : ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_RESPONSE_DIRECT_BIT_MODE;
    SERVICE_MODE_TYPE_REGISTER          : ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_RESPONSE_REGISTER_MODE;
    SERVICE_MODE_TYPE_PAGED             : ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_RESPONSE_PAGED_MODE;
  end;
  
  if ServiceModeInfo.ReadWrite = SERVICEMODE_WRITE then
  begin // Write
    ServiceModeInfo.iInstructionCountSent := 1;
    ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_WRITE_RECOVERY;
  end else
  begin // Read
    ServiceModeInfo.Value := ServiceModeInfo.ReadIndex;
    ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_RESULTS_READY;
  end;

  NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);
end;

// ***************************************************************************
//  procedure CommonServiceMode_NoAckHandler
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_NoAckHandler(BufferPtr: PDCCBufferInfo);
begin
  if ServiceModeInfo.ReadWrite = SERVICEMODE_READ then
  begin
    Inc(ServiceModeInfo.ReadIndex);                                   // Try the next Value
    if ServiceModeInfo.Value = ServiceModeInfo.ReadIndex then         // Have we run all the way around the horn once
    begin
      ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_NO_ACK;   // Run all possible values and an ACK was not found
      ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_RESULTS_READY
    end else
    begin
      ServiceModeInfo.iInstructionCountSent := 1;                       // Run the next possible Value cycle
      ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_RESET_CYCLE;   // Rurun it
    end;
  end else
  begin
    // No Ack, just quit
    ServiceModeInfo.iInstructionCountSent := 1;
    ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_NO_ACK;
    ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_RESULTS_READY;
  end;
  NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);
end;

// ***************************************************************************
//  procedure CommonServiceMode_DirectLoadTransmitterDirectMode
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_DirectLoadTransmitterDirectMode(BufferPtr: PDCCBufferInfo; CV_Address: Word; InstructionCode, DataByte: Byte);
var
  i: Integer;
begin
  BufferPtr^.TX_TransmittingPacket.PacketBytes[0] :=  %01110000 or InstructionCode or Hi(CV_Address);
  BufferPtr^.TX_TransmittingPacket.PacketBytes[1] := Lo(CV_Address);
  BufferPtr^.TX_TransmittingPacket.PacketBytes[2] := DataByte;
  BufferPtr^.TX_TransmittingPacket.Flags := 3;
  BufferPtr^.TX_XOR_Byte := 0;
  for i := 0 to 2 do
   BufferPtr^.TX_XOR_Byte := BufferPtr^.TX_XOR_Byte xor BufferPtr^.TX_TransmittingPacket.PacketBytes[i];
  BufferPtr^.TX_PreambleBitCount := PREAMBLE_BIT_COUNT_SERVICEMODE;
end;

// ***************************************************************************
//  procedure CommonServiceMode_DirectLoadTransmitterPagePreset
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_DirectLoadTransmitterPagePreset(BufferPtr: PDCCBufferInfo);
begin
  BufferPtr^.TX_TransmittingPacket.PacketBytes[0] := %01111101;
  BufferPtr^.TX_TransmittingPacket.PacketBytes[1] := %00000001;
  BufferPtr^.TX_TransmittingPacket.Flags := 2;
  BufferPtr^.TX_XOR_Byte := %011111100;
  BufferPtr^.TX_PreambleBitCount := PREAMBLE_BIT_COUNT_SERVICEMODE;
end;

// ***************************************************************************
//  procedure CommonServiceMode_DirectLoadTransmitter
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_DirectLoadTransmitter(BufferPtr: PDCCBufferInfo; RegisterOffset, ReadWrite, DataByte: Byte);
var
  i: Integer;
begin
  BufferPtr^.TX_TransmittingPacket.PacketBytes[0] :=  %01110000 or ReadWrite or RegisterOffset;
  BufferPtr^.TX_TransmittingPacket.PacketBytes[1] := DataByte;
  BufferPtr^.TX_TransmittingPacket.Flags := 2;
  BufferPtr^.TX_XOR_Byte := 0;
  for i := 0 to 1 do
   BufferPtr^.TX_XOR_Byte := BufferPtr^.TX_XOR_Byte xor BufferPtr^.TX_TransmittingPacket.PacketBytes[i];
  BufferPtr^.TX_PreambleBitCount := PREAMBLE_BIT_COUNT_SERVICEMODE;
end;

// ***************************************************************************
//  procedure CommonServiceMode_PowerOnCycle
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_PowerOnCycle(BufferPtr: PDCCBufferInfo; InstructionCount, NextState: Word);
begin
  if ServiceModeInfo.iInstructionCountSent < InstructionCount then
  begin
    Inc(ServiceModeInfo.iInstructionCountSent);
    NMRA_DCC_LoadIdlePacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE)
  end else
  begin
    ServiceModeInfo.iInstructionCountSent := 1;
    NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);    // Next State is always a Reset Packet for all Modes
    ServiceModeInfo.iStateMachine := NextState
  end
end;

// ***************************************************************************
//  procedure CommonServiceMode_ResetCycle
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_ResetCycle(BufferPtr: PDCCBufferInfo; InstructionPtr: PServiceModePtr; PacketCount: Word; NextState: Word; PrepareForAck: Boolean);
begin
  if ServiceModeInfo.iInstructionCountSent < PacketCount then
  begin
    Inc(ServiceModeInfo.iInstructionCountSent);
    NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE)
  end else
  begin
    ServiceModeInfo.iInstructionCountSent := 1;
    if InstructionPtr <> nil then
      InstructionPtr(BufferPtr)
    else
      NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);  // If the sender did not pass an Instruction pointer load the transmitter then fill in with an Idle Packet
    ServiceModeInfo.iStateMachine := NextState;
    if PrepareForAck then
      ResetACK;
  end;
end;

// ***************************************************************************
//  procedure CommonServiceMode_SendInstructions
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_SendInstructions(BufferPtr: PDCCBufferInfo; SendInstruction, AckHandler, NoAckHandler: PServiceModePtr; InstructionCount: Word);
begin
  if ServiceModeInfo.State.PROGRAMMING_ACK_DETECTED_BIT = 1 then
  begin                                                                 // ACK detected and we are done
    AckHandler(BufferPtr);
  end else
  if ServiceModeInfo.State.PROGRAMMING_ACK_FAILED_TO_DETECT_TRAILINGEDGE_BIT = 1 then
  begin
    ServiceModeInfo.Value := 0;
    ServiceModeInfo.ServiceModeResult := SERVICE_MODE_RESULT_SHORT_ACK;
    NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);  // Per 9.2.3
    ServiceModeInfo.iStateMachine := STATE_SERVICEMODE_RESULTS_READY;
  end else
  if ServiceModeInfo.State.PROGRAMMING_ACK_TIMER_DETECTED_LEADINGEDGE_BIT = 1 then
    NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE)       // Ack start detected so drop into Reset Packets are either success or failure handled above after 5ms
  else begin
    if ServiceModeInfo.iInstructionCountSent < InstructionCount then
    begin
      Inc(ServiceModeInfo.iInstructionCountSent);
      SendInstruction(BufferPtr);
    end else
    begin
      NoAckHandler(BufferPtr);
      ServiceModeInfo.iInstructionCountSent := 1;
    end
  end
end;

// ***************************************************************************
//  procedure CommonServiceMode_ResultReady
//
//  Parameters:  None
//
//  Result:  None
//
//  Description:
// ***************************************************************************
procedure CommonServiceMode_ResultReady(BufferPtr: PDCCBufferInfo);
begin
  // Spin here until the application calls ServiceMode_ReadResults to grab the Result and move to Done
  NMRA_DCC_LoadResetPacketIntoTransmitter(BufferPtr, PREAMBLE_BIT_COUNT_SERVICEMODE);  // Per 9.2.3  // Don't come out of Service Mode
end;

end.