PhysicalLayer.h

// PhysicalLayer.h
//
// Author: Mike McCauley (mikem@airspayce.com)
// Copyright (C) 2013 Mike McCauley
// $Id: PhysicalLayer.h,v 1.5 2013/07/13 11:28:33 mikem Exp $


#ifndef MAP27_PHYSICALLAYER_H
#define MAP27_PHYSICALLAYER_H

#include <stdint.h>

#include "Map27.h"
#include "FCS.h"

class Map27Port;
class Map27DataLayer;

// Special characters
#define STX 0x02
#define ETX 0x03
#define DLE 0x10
#define SYN 0x16

// Physical Layer Message types
#define MAP27_PHYSICAL_TYPE_LR              0x01
#define MAP27_PHYSICAL_TYPE_LA              0x02
#define MAP27_PHYSICAL_TYPE_LT              0x04

class Map27PhysicalLayer
{
public:
    Map27PhysicalLayer();

    void setPort(Map27Port* port);

    Map27Port* port();

    void setDataLayer(Map27DataLayer* dataLayer);

    Map27DataLayer* dataLayer();

    void reset();

    bool configure_rs232_port(uint32_t baud = 9600);

    void send(uint8_t *buf, uint16_t len);

    virtual void sendToPort(uint8_t ch);

    void sendLinkRequest(uint8_t n1, uint8_t k, uint8_t version);

    void sendLinkAcknowledge(uint8_t n_r, uint8_t n_k);

    void sendLinkTransfer(uint8_t n_s, uint8_t ar, uint8_t* buf, uint16_t bufLen);

    void poll();

    void clearRxBuf();

private:
    void handleRx(uint8_t ch);
    virtual void handleMessage();
    bool appendRxBuffer(uint8_t ch);
    virtual void handleLinkRequest(uint8_t n1, uint8_t k, uint8_t version);
    virtual void handleLinkAcknowledge(uint8_t n_r, uint8_t n_k);
    virtual void handleLinkTransfer(uint8_t n_s, uint8_t ar, uint8_t* buf, uint16_t bufLen);
    void sendFrameStart();
    void sendFrameData(uint8_t *buf, uint16_t len);
    void sendFrameEnd();
    void resetRx();

    // Receiver states
    typedef enum
    {
    RX_STATE_IDLE      = 1,
    RX_STATE_SYN       = 2,
    RX_STATE_DLE       = 3,
    RX_STATE_DATA      = 4,
    RX_STATE_ESCAPE    = 5,
    RX_STATE_WAIT_FCS1 = 6,
    RX_STATE_WAIT_FCS2 = 7
    } PhysicalRxState;

    // Physical Layer header structures
    typedef struct
    {
    uint8_t     type;     // MAP27_PHYSICAL_TYPE_LR
    uint8_t     n1;       // Maximum length
    uint8_t     k;        // Window size
    uint8_t     version;  // MAP27_PHYSICAL_VERSION
    } Map27PhysicalLR;
  
    typedef struct
    {
    uint8_t     type;     // MAP27_PHYSICAL_TYPE_LA
    uint8_t     n_r;      // Rx sequence number N(R)
    uint8_t     n_k;      // Rx credit number N(k)
    uint8_t     reserved; // 0
    } Map27PhysicalLA;
  
    typedef struct
    {
    uint8_t     type;     // MAP27_PHYSICAL_TYPE_LT
    uint8_t     n_s;      // Tx sequence number
    uint8_t     ar;       // Acknowledgement request 0/1
    uint8_t     reserved; // 0
    uint8_t     data[0];
    } Map27PhysicalLT;
  
    Map27Port* _port;
    Map27DataLayer* _dataLayer;
    Map27FCS   _rxFcs;
    Map27FCS   _txFcs;
    PhysicalRxState    _rxState;
    uint8_t    _rxBuf[MAP27_MAX_MESSAGE_LEN];
    uint16_t   _rxBufLen;
    uint16_t   _rxRecdFcs;
};

#endif