tsksio.cpp

这是一个关于C++编程开发的算法！

      }
   else 
      {
      if (portnum > ports)
         return;
      for (i = 0; i < portnum; i++)
         portp = portp->next;
      }

   if (portp->sio != NULL) /* Port already in use ? */
      return;

   portp->sio = this;

   pbase = port_base = portp->base;
   port = portp;

   /* Check if port accessible by modifying the modem control register */

   i = cmodcontrol = save_mcon = tsk_inp (pbase + modemcontrol);
   if (i & 0xe0)
      {
      port->sio = NULL;
      return;
      }
   tsk_nop ();
   tsk_outp (pbase + modemcontrol, 0xe0 | i);
   tsk_nop ();
   if (tsk_inp (pbase + modemcontrol) != (byte) i)
      {
      port->sio = NULL;
      return;
      }

   /* Port seems OK */

   civect = portp->vector;
   irqbit = (byte)(1 << (portp->irq & 0x07));

   wait_xmit = xmit_pending = 0;
   overrun = 0;
   flags = 0;
   modem_flags = 0;
   r_xoff = t_xoff = 0;
   rtsoff = 0;
   restore = 1;

   clcontrol = save_lcon = tsk_inp (pbase + linecontrol);
   tsk_nop ();
   save_inten = tsk_inp (pbase + intenable);
   tsk_nop ();

   if (init)
      {
      clcontrol = dflt_lcon;
      cmodcontrol = dflt_modcon;
      }

   tsk_outp (pbase + linecontrol, clcontrol | 0x80);
   tsk_nop ();
   save_bd1 = tsk_inp (pbase + baudreg_dll);
   tsk_nop ();
   save_bd2 = tsk_inp (pbase + baudreg_dlm);
   tsk_nop ();
   tsk_outp (pbase + linecontrol, clcontrol);
   tsk_nop ();

   tsk_outp (pbase + intenable, 0);

   if (irq_array [portp->irq] == NULL)
      {
      intptr = (intprocptr far *)MK_FP (0, civect * 4);
      tsk_cli ();
      savvect = *intptr;
      *intptr = irq_procs [portp->irq];
      tsk_sti ();
      }

   if (init)
      {
      tsk_outp (pbase + linecontrol, dflt_lcon | 0x80);
      tsk_nop ();
      tsk_outp (pbase + baudreg_dll, dflt_baud);
      tsk_nop ();
      tsk_outp (pbase + baudreg_dlm, dflt_baud >> 8);
      tsk_nop ();
      tsk_outp (pbase + linecontrol, dflt_lcon);
      tsk_nop ();
      tsk_outp (pbase + modemcontrol, dflt_modcon);
      tsk_nop ();
      }
   else
      {
      i = tsk_inp (pbase + modemcontrol) | OUT2;
      tsk_nop ();
      tsk_outp (pbase + modemcontrol, i);
      tsk_nop ();
      }

   while (tsk_inp (pbase + linestatus) & rxreadybit)
      {
      tsk_nop ();
      tsk_inp (pbase + receivedata);
      tsk_nop ();
      }
   tsk_nop ();

   tsk_inp (pbase + linestatus);
   tsk_nop ();
   modstat = tsk_inp (pbase + modemstatus);
   tsk_nop ();
   tsk_inp (pbase + intid);
   tsk_nop ();

   inta = (portp->irq > 7) ? inta11 : inta01;

   if (irq_array [portp->irq] == NULL)
      {
      if (portp->irq > 7)
         {
         i = tsk_inp (inta01) & ~CHAIN_IRQBIT;
         tsk_nop ();
         tsk_outp (inta01, i);
         }

      save_irq = (byte)((i = tsk_inp (inta)) & irqbit);
      tsk_nop ();
      tsk_outp (inta, i & ~irqbit);
      }
   else
      save_irq = (irq_array [portp->irq])->save_irq;

   tsk_cli ();
   next = irq_array [portp->irq];
   irq_array [portp->irq] = this;
   tsk_sti ();

   /* Enable interrupts with correction for possible loss of the 
      first tranmit interrupt on INS8250 and INS8250-B chips */
   for (;;)
       {
       if (tsk_inp (pbase + linestatus) & txreadybit)
           {
           break;
           }
       tsk_nop ();
       }

   tsk_nop ();
   tsk_cli ();
   tsk_outp (pbase + intenable, intdata);
   tsk_nop ();
   tsk_outp (pbase + intenable, intdata);
   tsk_sti ();

}


commport::~commport ()
   {
   intprocptr far *intptr;
   int pbase, i, inta;
   portptr portp;
   commptr curr, last;

   pbase = port_base;
   portp = port;

   last = NULL;
   curr = irq_array [portp->irq];
   while (curr != this && curr != NULL)
      {
      last = curr;
      curr = curr->next;
      }
   if (curr == NULL)
      return;

   tsk_outp (pbase + intenable, 0);
   tsk_cli ();
   if (last == NULL)
      irq_array [portp->irq] = next;
   else
      last->next = next;
   tsk_sti ();

   inta = (portp->irq > 7) ? inta11 : inta01;

   // ???? this was an input param, now a member that is set in constructor
   if (restore)
      {
      tsk_outp (pbase + modemcontrol, save_mcon);
      tsk_nop ();
      tsk_outp (pbase + linecontrol, save_lcon | 0x80);
      tsk_nop ();
      tsk_outp (pbase + baudreg_dll, save_bd1);
      tsk_nop ();
      tsk_outp (pbase + baudreg_dlm, save_bd2);
      tsk_nop ();
      tsk_outp (pbase + linecontrol, save_lcon);
      tsk_nop ();
      if (irq_array [portp->irq] == NULL)
         {
         tsk_cli ();
         tsk_outp (pbase + intenable, save_inten);
         i = tsk_inp (inta) & ~irqbit;
         tsk_nop ();
         tsk_outp (inta, i | save_irq);
         }
      }
   else if (irq_array [portp->irq] == NULL)
      {
      tsk_cli ();
      i = tsk_inp (inta) | irqbit;
      tsk_nop ();
      tsk_outp (inta, i);
      }

   if (irq_array [portp->irq] == NULL)
      {
      tsk_cli ();
      intptr = (intprocptr far *)MK_FP (0, civect * 4);
      *intptr = (intprocptr)savvect;
      }
   tsk_sti ();

   portp->sio = NULL;
   }


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

/*
   void change_rts (int on)
*/

void far commport::change_rts (int on)
{
   cmodcontrol = (cmodcontrol & ~RTS) | ((on) ? RTS : 0);
   tsk_outp (port_base + modemcontrol, cmodcontrol);
}

/*
   void change_dtr (int on)
*/

void far commport::change_dtr (int on)
{
   cmodcontrol = (cmodcontrol & ~DTR) | ((on) ? DTR : 0);
   tsk_outp (port_base + modemcontrol, cmodcontrol);
}


/*
   void far change_baud (int rate)
*/

void far commport::change_baud (long rate)
{
   int i;

   for (i = 0; baud_table [i]; i += 2)
      if (baud_table [i] == rate)
         break;
   if (!(i = (int)baud_table [i + 1]))
      return;

   tsk_outp (port_base + linecontrol, clcontrol | (byte)0x80);
   tsk_nop ();
   tsk_outp (port_base + baudreg_dll, (byte)i);
   tsk_nop ();
   tsk_outp (port_base + baudreg_dlm, (byte)(i >> 8));
   tsk_nop ();
   tsk_outp (port_base + linecontrol, clcontrol);
}


void far commport::change_parity (int par)
{
   clcontrol = (clcontrol & 0xc7) | par;
   tsk_outp (port_base + linecontrol, clcontrol);
}


void far commport::change_wordlength (int len)
{
   int i;

   switch (len)
      {
      case 5:  i = 0x00; break;
      case 6:  i = 0x01; break;
      case 7:  i = 0x02; break;
      case 8:  i = 0x03; break;
      default: return;
      }
   clcontrol = (clcontrol & 0xfc) | i;
   tsk_outp (port_base + linecontrol, clcontrol);
}


void far commport::change_stopbits (int n)
{
   int i;

   switch (n)
      {
      case 1:  i = 0x00; break;
      case 2:  i = 0x04; break;
      default: return;
      }
   clcontrol = (clcontrol & 0xfb) | i;
   tsk_outp (port_base + linecontrol, clcontrol);
}


void far commport::watch_modem (byte flags)
{
   modem_flags = flags & (CTS | DSR | RI | CD);
}


void far commport::protocol (int prot, word offthresh, word onthresh)
{
   byte old;
   
   old = flags;
   flags = (byte)prot;
   if (prot)
      {
      if (!offthresh)
         offthresh = 10;
      xoff_threshold = offthresh;
      if (onthresh <= offthresh)
         onthresh = offthresh + 10;
      xon_threshold = onthresh;
      }

   if ((old & RTSCTS) != ((byte)prot & RTSCTS))
      {
      chng_rts (1);
      modem_flags = (modem_flags & ~CTS) |
                         ((prot & RTSCTS) ? CTS : 0);
      }

   if (!(prot & XONXOFF))
      {
      if (r_xoff)
         r_xoff = -2;
      t_xoff = 0;
      }

   if (!xmit_pending)
      transmit_ready ();
}


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


int far commport::send (byte ch, dword timeout)
{
   int res;

   if ((res = xmit_pipe.write_pipe (ch, timeout)) < 0)
      return res;
   tsk_cli ();
   if (!xmit_pending)
      transmit_ready ();
   tsk_sti ();
   return 0;
}


int far commport::receive (dword timeout)
{
   int res;
   
   if ((res = (int)rcv_pipe.read_wpipe (timeout)) < 0)
      return res;

   if (!flags)
      return res;

   if (rcv_pipe.wpipe_free () > xon_threshold)
      {
      tsk_cli ();
      if (r_xoff)
         {
         r_xoff = -2;
         if (!xmit_pending)
            transmit_ready ();
         }
      tsk_sti ();

      if (rtsoff)
         chng_rts (1);
      }
   return res;
}


int far commport::rcv_overrun (void)
{
   int res;

   res = overrun;
   overrun = 0;
   return res;
}


int far commport::check (void)
{
   return rcv_pipe.check_wpipe ();
}


int far commport::modem_status (void)
{
   return modstat;
}


int far commport::complete (void)
{
   return (xmit_pipe.check_pipe () == -1);
}


int far commport::wait_complete (dword timeout)
{
   return xmit_pipe.wait_pipe_empty (timeout);
}


void far commport::flush_receive (void)
{
    rcv_pipe.flush_wpipe ();
}