/*
    -- pcserial.h -- Tony Givargis
    Interrupt driven PC serial interface.
*/

/*---------------------------------------------------------------------------*/

#ifndef __pcserial_h__
#define __pcserial_h__

/*---------------------------------------------------------------------------*/

#include "l_queue.h"

/*---------------------------------------------------------------------------*/

/*
    EL_Port

    Serial Port enumeration/
*/
typedef enum { COM1, COM2 } EL_Port;

/*---------------------------------------------------------------------------*/

/*
    EL_Parity

    Serial Port's pariy enumeration.
*/
typedef enum { NONE, ODD, EVEN } EL_Parity;

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPort

    Returned by EL_SerialPortCreate function as the ADT identifier (handle)
    of a serial i/0 port.
*/
typedef struct {

    EL_Queue* queue;
    unsigned comInt;
    unsigned comAdr;
    unsigned lcr;
    unsigned baudHi;
    unsigned baudLo;
    unsigned pic;
    void* oldISR;

} EL_SerialPort;

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPort

    Initializes the (port) and returns an EL_SerialPort* on success or NULL
    otherwise to be use in subsequent calls to serial port functions.
*/
EL_SerialPort* EL_SerialPortCreate(EL_Port port, EL_Parity parity,
                                   long baudRate, int dataBits, int stopBits);

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPortClose

    Destroys (serialPort).
*/
void EL_SerialPortDestroy(EL_SerialPort* serialPort);

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPortRead

    Reads from (serialPort) (szBuf) bytes into (buf). Returns the number
    of bytes actually read. The use of EL_SerialPortQueueSize before a call
    to this function is recommended.
*/
unsigned EL_SerialPortRead(EL_SerialPort* serialPort,
                           void* buf, unsigned szBuf);

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPortWrite

    Writes to (serialPort) (szBuf) bytes from (buf).
*/
void EL_SerialPortWrite(EL_SerialPort* serialPort,
                        void* buf, unsigned szBuf);

/*---------------------------------------------------------------------------*/

/*
    EL_SerialPortQueueSize

    Returns the number of elements availabe for read in receive queue of
    (serialPort).
*/
#define EL_SerialPortQueueSize(serialPort) EL_QueueSize((serialPort)->queue)

/*---------------------------------------------------------------------------*/

#endif