isotp.h

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#pragma once
 
#include "fifo_buffer.h"
#include "can.h"
#include "can_msg_tx.h"
#include "can_listener.h"
 
#if EFI_UNIT_TEST
#define PRINT printf
#define PRINT_EOL "\n"
#else
#define PRINT efiPrintf
#define PRINT_EOL ""
#endif
 
#if EFI_PROD_CODE | EFI_SIMULATOR
#define can_msg_t msg_t
#define can_sysinterval_t sysinterval_t
#define CAN_MSG_OK MSG_OK
#define CAN_MSG_TIMEOUT MSG_TIMEOUT
#else
#include "can_mocks.h"
#endif /* EFI_UNIT_TEST */
 
#define CAN_FLOW_STATUS_OK 0
#define CAN_FLOW_STATUS_WAIT_MORE 1
#define CAN_FLOW_STATUS_ABORT 2
 
enum IsoTpFrameType {
    ISO_TP_FRAME_SINGLE = 0,
    ISO_TP_FRAME_FIRST = 1,
    ISO_TP_FRAME_CONSECUTIVE = 2,
    ISO_TP_FRAME_FLOW_CONTROL = 3,
};
 
class IsoTpFrameHeader {
public:
    IsoTpFrameType frameType;
 
    // used for 'single' or 'first' frames
    int numBytes;
    // used for 'consecutive' frames
    int index;
    // used for 'flow control' frames
    int fcFlag;
    int blockSize;
    int separationTime;
};
 
// todo: what's the point of this wrapper/holder class anyway?
class CanRxMessage {
public:
    CanRxMessage() {}
 
    CanRxMessage(const CANRxFrame &f) {
        frame = f;
    }
 
    CanRxMessage(const CanRxMessage& msg) : frame(msg.frame) {}
 
    CanRxMessage& operator=(const CanRxMessage& msg) {
    // full content copy
        frame = msg.frame;
        return *this;
    }
 
public:
    CANRxFrame frame;
};
 
class CanRxMessageSource {
public:
  virtual bool get(CanRxMessage &item, int timeout) = 0;
};
 
class ICanTransmitter {
public:
  virtual can_msg_t transmit(CanTxMessage &ctfp, can_sysinterval_t timeout) = 0;
};
 
class ICanReceiver {
public:
  virtual can_msg_t receive(CANRxFrame *crfp, can_sysinterval_t timeout) = 0;
  virtual void onTpFirstFrame() = 0;
};
 
class IsoTpBase {
public:
    IsoTpBase(ICanTransmitter *p_txTransport, size_t p_busIndex, uint32_t p_rxFrameId, uint32_t p_txFrameId)
        :
        txTransport(p_txTransport),
        busIndex(p_busIndex),
        rxFrameId(p_rxFrameId),
        txFrameId(p_txFrameId)
        {}
 
    int sendFrame(const IsoTpFrameHeader & header, const uint8_t *data, int num, can_sysinterval_t timeout);
 
    can_msg_t transmit(CanTxMessage &ctfp, can_sysinterval_t timeout) {
        if (isoHeaderByteIndex) {
            // yes that would be truncated to byte, that's expected
            ctfp[0] = rxFrameId & 0xff;
        }
        if (txTransport) {
            return txTransport->transmit(ctfp, timeout);
        }
        return CAN_MSG_OK;
    }
 
    // Offset of first ISO-TP byte, usually 0
    // but some vendors add some specific data in first CAN byte
    size_t isoHeaderByteIndex = 0;
 
    ICanTransmitter *txTransport;
 
    size_t busIndex;
    uint32_t rxFrameId;
    uint32_t txFrameId;
};
 
// We need an abstraction layer for unit-testing
// todo: no reason for composite entity to exist, keep splitting CanStreamerState into RX and TX!
class ICanTransport : public ICanTransmitter, public ICanReceiver {
};
 
// most efficient sizes are 6 + x * 7 that way whole buffer is transmitted as (x+1) full packets
#ifndef CAN_FIFO_BUF_SIZE
#define CAN_FIFO_BUF_SIZE 76
#endif // CAN_FIFO_BUF_SIZE
 
#define CAN_FIFO_FRAME_SIZE 8
 
class CanStreamerState : public IsoTpBase {
public:
  // serial_can uses fifo_buffer_sync, unify?
    fifo_buffer<uint8_t, CAN_FIFO_BUF_SIZE> rxFifoBuf;
    fifo_buffer<uint8_t, CAN_FIFO_BUF_SIZE> txFifoBuf;
 
/*
#if defined(TS_CAN_DEVICE_SHORT_PACKETS_IN_ONE_FRAME)
    // used to restore the original packet with CRC
    uint8_t shortCrcPacketStagingArea[13];
#endif
*/
    // used for multi-frame ISO-TP packets
    int waitingForNumBytes = 0;
    int waitingForFrameIndex = 0;
 
    ICanReceiver *rxTransport;
 
public:
    CanStreamerState(ICanTransmitter *p_txTransport, ICanReceiver *p_rxTransport, size_t p_busIndex, uint32_t p_rxFrameId, uint32_t p_txFrameId)
        :
        IsoTpBase(p_txTransport, p_busIndex, p_rxFrameId, p_txFrameId),
        rxTransport(p_rxTransport)
    {}
 
    bool isComplete{};
 
    void reset();
 
    int sendFrame(const IsoTpFrameHeader & header, const uint8_t *data, int num, can_sysinterval_t timeout);
    int receiveFrame(const CANRxFrame &rxmsg, uint8_t *buf, int num, can_sysinterval_t timeout);
    int getDataFromFifo(uint8_t *rxbuf, size_t &numBytes);
    // returns the number of bytes sent
    int sendDataTimeout(const uint8_t *txbuf, int numBytes, can_sysinterval_t timeout);
 
    // streaming support for TS I/O (see tunerstudio_io.cpp)
    can_msg_t streamAddToTxTimeout(size_t *np, const uint8_t *txbuf, can_sysinterval_t timeout);
    can_msg_t streamFlushTx(can_sysinterval_t timeout);
    can_msg_t streamReceiveTimeout(size_t *np, uint8_t *rxbuf, can_sysinterval_t timeout);
};
 
#define ISOTP_RX_QUEUE_LEN  4
 
class IsoTpRx : public CanListener, public IsoTpBase {
public:
    IsoTpRx(size_t p_busIndex, uint32_t p_rxFrameId, uint32_t p_txFrameId)
    :
        CanListener(p_rxFrameId),
        IsoTpBase(nullptr, p_busIndex, p_rxFrameId, p_txFrameId)
    {
        rxFifoBuf.clear();
        registerCanListener(*this);
    }
 
    ~IsoTpRx() {
        unregisterCanListener(*this);
    }
 
    void reset() {
        rxFifoBuf.clear();
        waitingForNumBytes = 0;
        waitingForFrameIndex = 0;
    }
 
    /* CAN messages entry point */
    virtual void decodeFrame(const CANRxFrame& frame, efitick_t nowNt)
    {
        if (frame.DLC < 1 + isoHeaderByteIndex) {
            // invalid++;
            return;
        }
 
        if (isoHeaderByteIndex) {
            if (frame.data8[0] != (txFrameId & 0xff)) {
                return;
            }
        }
 
        if (!rxFifoBuf.put(frame)) {
            // overruns++;
        }
    }
 
    /* User app entry point */
    int readTimeout(uint8_t *rxbuf, size_t *size, sysinterval_t timeout);
 
private:
    // used for multi-frame ISO-TP packets
    int waitingForNumBytes = 0;
    uint8_t waitingForFrameIndex = 0;
 
protected:
    fifo_buffer_sync<CANRxFrame, ISOTP_RX_QUEUE_LEN> rxFifoBuf;
};
 
class IsoTpRxTx : public IsoTpRx {
public:
    IsoTpRxTx(size_t p_busIndex, uint32_t p_rxFrameId, uint32_t p_txFrameId)
    :
        IsoTpRx(p_busIndex, p_rxFrameId, p_txFrameId)
        {}
 
    int writeTimeout(const uint8_t *txbuf, size_t size, sysinterval_t timeout);
};