// ****************************************************************************
//
// File Name:    comm.c
//
// Description: Handheld program serial communication routines. 
//
//  ORIGINATOR: Mark C. Lampkin. Lampkin Software Works,  (C)1994.
//              386 Merriweather
//              Grosse Pointe Farms, MI.  48236
//              (313) 884-8759
//              Version 1.2A
//
//  HISTORY
//    who     when     what
// -------- --------- ----------------------------------------------------
//  Geof    09-10-97  Took over. Added more baud rate settings and modem
//                    control register settings.
//  Geof    04-06-98  Moved om_buf_clr(), com_rec_buf(), and SendStream() 
//                    from hms800.c to this file.
//  Geof    11-18-98  Dump debug information to a file, like ABx Fast and ASCII.
//
// ****************************************************************************

#include <dos.h>
#include <ctype.h>
#include <conio.h>
#include <bios.h>
#include <io.h>
#include <string.h>
#include <stdlib.h>
#include <graphics.h>
#include <time.h>
#include "typedef.h"
#include "handheld.h"    // For device type.
#include "comm.h"

#if PRINT_CMDS
#include <stdio.h>
#endif

#define CBS     16384   /* RS-232 input buffer size (a guess) */

#define COM1        1   /* port number parameters for comm_open() */
#define COM2        2

#define MDMDAT1     0x03F8  /* Address of modem port 1 data */
#define MDMSTS1     0x03FD  /* Address of modem port 1 status  */
#define MDMCOM1     0x03FB  /* Address of modem port 1 command */
#define MDMDAT2     0x02F8  /* Address of modem port 2 data */
#define MDMSTS2     0x02FD  /* Address of modem port 2 status */
#define MDMCOM2     0x02FB  /* Address of modem port 2 command */
#define MDMINTV     0x000C  /* Com 1 interrupt vector */
#define MDINTV2     0x000B  /* Com 2 interrupt vector */

#define MDMINTO     0x0EF   /* Mask to enable IRQ3 for port 1 */
#define MDMINTC     0x010   /* Mask to Disable IRQ4 for port 1 */

#define MDINTC2     0x008   /* Mask to Disable IRQ3 for port 2 */
#define MDINTO2     0x0F7   /* Mask to enable IRQ4 for port 2 */

#define INTCONT     0x0021  /* 8259 interrupt controller ICW2-3 */
#define INTCON1     0x0020  /* Address of 8259 ICW1 */

#if TEST_MUX32
BYTE now_mux_addr = MUX_ADDR; // If using MUX32 then this is the MUX32 address.
#endif

#if PRINT_CMDS
static BYTE prt_fname[] = "debug.txt";   // Dump debug information.
static FILE *debug_file;           // Point to debug file information, from the open.
#endif

static void interrupt (far *oldvec)();
static uint     intv;           /* interrupt number to usurp */

static int
    dat8250,                /* 8250 data register */
    stat8250,               /* 8250 line-status register */
    com8250,                /* 8250 line-control register */
    c_in_buf = 0,           /* count of characters received */
    xoffpt,                 /* amount of buffer that forces XOFF */
    xonpt,                  /* amount of buffer that unXOFFs */
    xonxoff = FALSE,        /* auto xon/xoff support flag */
    xofsnt  = FALSE;        /* XOFF transmitted flag */
    //xofrcv  = 0;          /* XOFF received flag */

static char
    en8259,                 /* 8259 IRQ enable mask */
    dis8259,                /* 8259 IRQ disable mask */
    buffer[CBS],            /* Communications circular buffer */
    *inptr = buffer,        /* input address of circular buffer */
    *outptr = buffer;       /* output address of circular buffer */
    work_buffer[256];       /* program 'in process' buffer */
    *pointer = work_buffer; /* address of working buffer */

/* Function Prototypes */
static void dobaud(long unsigned int);  

/* Functions */

void reset();
void start();
void stop();


// ****************************************************************************
// Serial interrupt routine, to actual receive data from the COM port.
//
// Input:        NONE.
// Return:       NONE.
// Side effects: Receive buffer and pointer are updated.
void interrupt serint(void)
{
    *inptr++ = inportb(dat8250);    /* Store character in buffer */
    c_in_buf++;                     /* and increment count */

    if (xonxoff)  {                 /* if xon/xoff auto-support is on */
        if ((c_in_buf > xoffpt) && !xofsnt)  {

            /* buffer nearly full */

            comm_putc(XOFF);        /* send an XOFF */
            xofsnt = TRUE;          /* and say so */
        }
    }

    disable();                      /* ints off for ptr change */
    if (inptr == &buffer[CBS])      /* wrap buffer input pointer if end */
        inptr = buffer;

    enable();
    outportb(0x20, 0x20);           /* Generic EOI to 8259 */
}

/* installs comm interrupts */

// ****************************************************************************
// Set the UART's control register selection.  What UART is open for this 
// COM port?  Setup to access it.
//
// Input:        Port number.
// Return:       BOOLEAN - TRUE of valid port number.
//                       - FALSE if not valid port number.
// Side effects: Global variables are setup for this COM port.
static unsigned char what_port(int port_number)
{
    uint    be = biosequip();       /* to get # installed serial ports */

    be <<= 4;                       /* shift-wrap high bits off */
    be >>= 13;                      /* shift down to low bits */

    if (be >= port_number)  
    {
        if (port_number == 1)  
        {
            dat8250  = MDMDAT1;
            stat8250 = MDMSTS1;
            com8250  = MDMCOM1;
            dis8259  = MDMINTC;
            en8259   = MDMINTO;
            intv     = MDMINTV;
        } else if (port_number == 2)  
        {
            dat8250  = MDMDAT2;
            stat8250 = MDMSTS2;
            com8250  = MDMCOM2;
            dis8259  = MDINTC2;
            en8259   = MDINTO2;
            intv     = MDINTV2;
        }
    } else
        return(FALSE);
    return(TRUE);
}


// ****************************************************************************
// configure this PC's COM port to a new baud rate.
//
// Input:        New baud rate value.
// Return:       NONE.
// Side effects: NONE.
static void dobaud(long unsigned int  baudrate)
{
    uchar   portval, blo, bhi;

    switch (baudrate)  {    /* Baud rate LSB's and MSB's */
    case 50:     bhi = 0x9;  blo = 0x00;  break;
    case 75:     bhi = 0x6;  blo = 0x00;  break;
    case 110:    bhi = 0x4;  blo = 0x17;  break;
    case 150:    bhi = 0x3;  blo = 0x00;  break;
    case 300:    bhi = 0x1;  blo = 0x80;  break;
    case 600:    bhi = 0x0;  blo = 0xC0;  break;
    case 1200:   bhi = 0x0;  blo = 0x60;  break;
    case 1800:   bhi = 0x0;  blo = 0x40;  break;
    case 2000:   bhi = 0x0;  blo = 0x3A;  break;
    case 2400:   bhi = 0x0;  blo = 0x30;  break;
    case 4800:   bhi = 0x0;  blo = 0x18;  break;
    case 9600:   bhi = 0x0;  blo = 0x0C;  break;
    case 19200:  bhi = 0x0;  blo = 0x06;  break;
    case 38400:  bhi = 0x0;  blo = 0x03;  break;
    case 57600:  bhi = 0x0;  blo = 0x02;  break;
    case 115200: bhi = 0x0;  blo = 0x01;  break;
    default:
        return;
    }

    portval = inportb(com8250);         /* read Line-Control Reg val */
    outportb(com8250, portval | 0x80);  /* set high bit for baud init */
    outportb(dat8250, blo);             /* Send LSB for baud rate */
    outportb(dat8250+1, bhi);           /* Send MSB for baud rate */
    outportb(com8250, portval);         /* Reset initial value at LCR */
}

// ****************************************************************************
// data read (dread), read data from the circular buffer
//
// Input:        Pointer to buffer to fill.
//               Number of BYTEs wonted.
//               Number of seconds to wait for the desired BYTEs.
// Return:       NONE.
// Side effects: NONE.
static int dread(BYTE *buffer, WORD wanted, WORD seconds)
{
   register int    i;
   long            start;
   int             pending, elapsed;

   start = time((long *)NULL);
   for (;;)  
   {
      pending = comm_avail();
      if (pending >= wanted)  // got enough in the buffer?
      {       
#if PRINT_CMDS
         fprintf(debug_file, "Received: ");
#endif
         for (i = 0; i < wanted; i++)
#if PRINT_CMDS
            fprintf(debug_file, "%02x ", *buffer++ = comm_getc());
         fprintf(debug_file, "\n");
#else
            *buffer++ = comm_getc();
#endif
         return TRUE;
      } else  
      {
         elapsed = time((long *)NULL) - start;
         if (elapsed >= seconds)
            return FALSE;
      }
   }
}

#if FALSE
// ****************************************************************************
// Put a srting out the COM port.
//
// Input:        String pointer.
// Return:       NONE.
// Side effects: NONE.
static void comm_puts(BYTE *s_message) 
{
    uchar   x;

    while(*s_message > 0) 
    {
       x = *s_message++;
       comm_putc(x);
    }
}