termios.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

  /* check for incoming RTS/CTS flow control switched off */
  if (( tty->flow_ctrl & FL_MDRTS) &&
      !(tty->termios.c_cflag & CRTSCTS)) {
    /* clear related flags in flow_ctrl */
    tty->flow_ctrl &= ~(FL_MDRTS);
    
    /* restart remote Tx, if it was stopped */
    if ((tty->flow_ctrl & FL_IRTSOFF) &&
	(tty->device.startRemoteTx != NULL)) {
      tty->device.startRemoteTx(tty->minor);
    }
    tty->flow_ctrl &= ~(FL_IRTSOFF);
  }    
  
  /* 
   * check for flow control options to be switched on  
   */
  /* check for incoming RTS/CTS flow control switched on */
  if (tty->termios.c_cflag & CRTSCTS) {
    tty->flow_ctrl |= FL_MDRTS;
  }
  /* check for incoming XON/XOF flow control switched on */
  if (tty->termios.c_iflag & IXOFF) {
    tty->flow_ctrl |= FL_MDXOF;
  }
  /* check for outgoing XON/XOF flow control switched on */
  if (tty->termios.c_iflag & IXON) {
    tty->flow_ctrl |= FL_MDXON;
  }
}

rtems_status_code
rtems_termios_ioctl (void *arg)
{
	rtems_libio_ioctl_args_t *args = arg;
	struct rtems_termios_tty *tty = args->iop->data1;
	struct ttywakeup         *wakeup = (struct ttywakeup *)args->buffer;
	rtems_status_code sc;

 	args->ioctl_return = 0;
	sc = rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
	if (sc != RTEMS_SUCCESSFUL) {
		args->ioctl_return = sc;
		return sc;
	}
	switch (args->command) {
	default:
		if (linesw[tty->t_line].l_ioctl != NULL) {
			sc = linesw[tty->t_line].l_ioctl(tty,args);
		}
		else {
			sc = RTEMS_INVALID_NUMBER;
		}
		break;

	case RTEMS_IO_GET_ATTRIBUTES:
		*(struct termios *)args->buffer = tty->termios;
		break;

	case RTEMS_IO_SET_ATTRIBUTES:
		tty->termios = *(struct termios *)args->buffer;

		/* check for and process change in flow control options */
		termios_set_flowctrl(tty);

		if (tty->termios.c_lflag & ICANON) {
			tty->rawInBufSemaphoreOptions = RTEMS_WAIT;
			tty->rawInBufSemaphoreTimeout = RTEMS_NO_TIMEOUT;
			tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT;
		}
		else {
			rtems_interval ticksPerSecond;
			rtems_clock_get (RTEMS_CLOCK_GET_TICKS_PER_SECOND, &ticksPerSecond);
			tty->vtimeTicks = tty->termios.c_cc[VTIME] * ticksPerSecond / 10;
			if (tty->termios.c_cc[VTIME]) {
				tty->rawInBufSemaphoreOptions = RTEMS_WAIT;
				tty->rawInBufSemaphoreTimeout = tty->vtimeTicks;
				if (tty->termios.c_cc[VMIN])
					tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT;
				else
					tty->rawInBufSemaphoreFirstTimeout = tty->vtimeTicks;
			}
			else {
				if (tty->termios.c_cc[VMIN]) {
					tty->rawInBufSemaphoreOptions = RTEMS_WAIT;
					tty->rawInBufSemaphoreTimeout = RTEMS_NO_TIMEOUT;
					tty->rawInBufSemaphoreFirstTimeout = RTEMS_NO_TIMEOUT;
				}
				else {
					tty->rawInBufSemaphoreOptions = RTEMS_NO_WAIT;
				}
			}
		}
		if (tty->device.setAttributes)
			(*tty->device.setAttributes)(tty->minor, &tty->termios);
		break;

	case RTEMS_IO_TCDRAIN:
		drainOutput (tty);
		break;

	case RTEMS_IO_SNDWAKEUP:
		tty->tty_snd = *wakeup;
		break;

	case RTEMS_IO_RCVWAKEUP:
		tty->tty_rcv = *wakeup;
		break;

		/*
		 * FIXME: add various ioctl code handlers
		 */

#if 1 /* FIXME */
	case TIOCSETD:
		/*
		 * close old line discipline
		 */
		if (linesw[tty->t_line].l_close != NULL) {
			sc = linesw[tty->t_line].l_close(tty);
		}
		tty->t_line=*(int*)(args->buffer);
		tty->t_sc = NULL; /* ensure that no more valid data */
		/*
		 * open new line discipline
		 */
		if (linesw[tty->t_line].l_open != NULL) {
			sc = linesw[tty->t_line].l_open(tty);
		}
		break;
	case TIOCGETD:	
		*(int*)(args->buffer)=tty->t_line;
		break;		
#endif
 	case FIONREAD:
		{
		int rawnc = tty->rawInBuf.Tail - tty->rawInBuf.Head;
		if ( rawnc < 0 )
			rawnc += tty->rawInBuf.Size;
		/* Half guess that this is the right operation */
		*(int *)args->buffer = tty->ccount - tty->cindex + rawnc;
		}
		break;
	}
	rtems_semaphore_release (tty->osem);
	args->ioctl_return = sc;
	return sc;
}

/*
 * Send characters to device-specific code
 */
void
rtems_termios_puts (const char *buf, int len, struct rtems_termios_tty *tty)
{
	unsigned int newHead;
	rtems_interrupt_level level;
	rtems_status_code sc;

	if (tty->device.outputUsesInterrupts == TERMIOS_POLLED) {
		(*tty->device.write)(tty->minor, buf, len);
		return;
	}
	newHead = tty->rawOutBuf.Head;
	while (len) {
		/*
		 * Performance improvement could be made here.
		 * Copy multiple bytes to raw buffer:
		 * if (len > 1) && (space to buffer end, or tail > 1)
		 *	ncopy = MIN (len, space to buffer end or tail)
		 *	memcpy (raw buffer, buf, ncopy)
		 *	buf += ncopy
		 *	len -= ncopy
		 *
		 * To minimize latency, the memcpy should be done
		 * with interrupts enabled.
		 */
		newHead = (newHead + 1) % tty->rawOutBuf.Size;
		rtems_interrupt_disable (level);
		while (newHead == tty->rawOutBuf.Tail) {
			tty->rawOutBufState = rob_wait;
			rtems_interrupt_enable (level);
			sc = rtems_semaphore_obtain (tty->rawOutBuf.Semaphore,
							RTEMS_WAIT,
							RTEMS_NO_TIMEOUT);
			if (sc != RTEMS_SUCCESSFUL)
				rtems_fatal_error_occurred (sc);
			rtems_interrupt_disable (level);
		}
		tty->rawOutBuf.theBuf[tty->rawOutBuf.Head] = *buf++;
		tty->rawOutBuf.Head = newHead;
		if (tty->rawOutBufState == rob_idle) {
		  /* check, whether XOFF has been received */
		  if (!(tty->flow_ctrl & FL_ORCVXOF)) {
		    (*tty->device.write)(tty->minor,
			(char *)&tty->rawOutBuf.theBuf[tty->rawOutBuf.Tail],1);
		  }
		  else {
		    /* remember that output has been stopped due to flow ctrl*/
		    tty->flow_ctrl |= FL_OSTOP; 
		  }
		  tty->rawOutBufState = rob_busy;
		}
		rtems_interrupt_enable (level);
		len--;
	}
}

/*
 * Handle output processing
 */
static void
oproc (unsigned char c, struct rtems_termios_tty *tty)
{
	int	i;

	if (tty->termios.c_oflag & OPOST) {
		switch (c) {
		case '\n':
			if (tty->termios.c_oflag & ONLRET)
				tty->column = 0;
			if (tty->termios.c_oflag & ONLCR) {
				rtems_termios_puts ("\r", 1, tty);
				tty->column = 0;
			}
			break;

		case '\r':
			if ((tty->termios.c_oflag & ONOCR) && (tty->column == 0))
				return;
			if (tty->termios.c_oflag & OCRNL) {
				c = '\n';
				if (tty->termios.c_oflag & ONLRET)
					tty->column = 0;
				break;
			}
			tty->column = 0;
			break;

		case '\t':
			i = 8 - (tty->column & 7);
			if ((tty->termios.c_oflag & TABDLY) == XTABS) {
				tty->column += i;
				rtems_termios_puts ( "        ",  i, tty);
				return;
			}
			tty->column += i;
			break;

		case '\b':
			if (tty->column > 0)
				tty->column--;
			break;

		default:
			if (tty->termios.c_oflag & OLCUC)
				c = toupper(c);
			if (!iscntrl(c))
				tty->column++;
			break;
		}
	}
	rtems_termios_puts (&c, 1, tty);
}

rtems_status_code
rtems_termios_write (void *arg)
{
	rtems_libio_rw_args_t *args = arg;
	struct rtems_termios_tty *tty = args->iop->data1;
	rtems_status_code sc;

	sc = rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
	if (sc != RTEMS_SUCCESSFUL)
		return sc;
	if (linesw[tty->t_line].l_write != NULL) {
		sc = linesw[tty->t_line].l_write(tty,args);
		rtems_semaphore_release (tty->osem);
		return sc;
	}
	if (tty->termios.c_oflag & OPOST) {
		unsigned32 count = args->count;
		unsigned8 *buffer = args->buffer;
		while (count--)
			oproc (*buffer++, tty);
		args->bytes_moved = args->count;
	}
	else {
		rtems_termios_puts (args->buffer, args->count, tty);
		args->bytes_moved = args->count;
	}
	rtems_semaphore_release (tty->osem);
	return sc;
}

/*
 * Echo a typed character
 */
static void
echo (unsigned char c, struct rtems_termios_tty *tty)
{
	if ((tty->termios.c_lflag & ECHOCTL) && iscntrl(c) && (c != '\t') && (c != '\n')) {
		char echobuf[2];

		echobuf[0] = '^';
		echobuf[1] = c ^ 0x40;
		rtems_termios_puts (echobuf, 2, tty);
		tty->column += 2;
	}
	else {
		oproc (c, tty);
	}
}

/*
 * Erase a character or line
 * FIXME: Needs support for WERASE and ECHOPRT.
 * FIXME: Some of the tests should check for IEXTEN, too.
 */
static void
erase (struct rtems_termios_tty *tty, int lineFlag)
{
	if (tty->ccount == 0)
		return;
	if (lineFlag) {
		if (!(tty->termios.c_lflag & ECHO)) {
			tty->ccount = 0;
			return;
		}
		if (!(tty->termios.c_lflag & ECHOE)) {
			tty->ccount = 0;
			echo (tty->termios.c_cc[VKILL], tty);
			if (tty->termios.c_lflag & ECHOK)
				echo ('\n', tty);
			return;
		}
	}
	while (tty->ccount) {
		unsigned char c = tty->cbuf[--tty->ccount];

		if (tty->termios.c_lflag & ECHO) {
			if (!lineFlag && !(tty->termios.c_lflag & ECHOE)) {
				echo (tty->termios.c_cc[VERASE], tty);
			}
			else if (c == '\t') {
				int col = tty->read_start_column;
				int i = 0;

				/*
				 * Find the character before the tab
				 */
				while (i != tty->ccount) {
					c = tty->cbuf[i++];
					if (c == '\t') {
						col = (col | 7) + 1;
					}
					else if (iscntrl (c)) {
						if (tty->termios.c_lflag & ECHOCTL)
							col += 2;
					}
					else {
						col++;
					}
				}

				/*
				 * Back up over the tab
				 */
				while (tty->column > col) {
					rtems_termios_puts ("\b", 1, tty);
					tty->column--;
				}
			}
			else {
				if (iscntrl (c) && (tty->termios.c_lflag & ECHOCTL)) {
					rtems_termios_puts ("\b \b", 3, tty);
					if (tty->column)
						tty->column--;
				}
				if (!iscntrl (c) || (tty->termios.c_lflag & ECHOCTL)) {
					rtems_termios_puts ("\b \b", 3, tty);
					if (tty->column)
						tty->column--;
				}
			}
		}
		if (!lineFlag)
			break;
	}
}

/*
 * Process a single input character
 */
static int
iproc (unsigned char c, struct rtems_termios_tty *tty)
{
	if (tty->termios.c_iflag & ISTRIP)
		c &= 0x7f;
	if (tty->termios.c_iflag & IUCLC)
		c = tolower (c);
	if (c == '\r') {
		if (tty->termios.c_iflag & IGNCR)
			return 0;
		if (tty->termios.c_iflag & ICRNL)
			c = '\n';
	}
	else if ((c == '\n') && (tty->termios.c_iflag & INLCR)) {
		c = '\r';
	}
	if ((c != '\0') && (tty->termios.c_lflag & ICANON)) {
		if (c == tty->termios.c_cc[VERASE]) {
			erase (tty, 0);
			return 0;
		}
		else if (c == tty->termios.c_cc[VKILL]) {
			erase (tty, 1);
			return 0;
		}
		else if (c == tty->termios.c_cc[VEOF]) {
			return 1;
		}
		else if (c == '\n') {
			if (tty->termios.c_lflag & (ECHO | ECHONL))
				echo (c, tty);
			tty->cbuf[tty->ccount++] = c;
			return 1;
		}
		else if ((c == tty->termios.c_cc[VEOL])
		      || (c == tty->termios.c_cc[VEOL2])) {
			if (tty->termios.c_lflag & ECHO)
				echo (c, tty);
			tty->cbuf[tty->ccount++] = c;
			return 1;
		}
	}

	/*
	 * FIXME: Should do IMAXBEL handling somehow
	 */
	if (tty->ccount < (CBUFSIZE-1)) {
		if (tty->termios.c_lflag & ECHO)
			echo (c, tty);
		tty->cbuf[tty->ccount++] = c;
	}
	return 0;
}

/*
 * Process input character, with semaphore.
 */
static int
siproc (unsigned char c, struct rtems_termios_tty *tty)
{
	int i;

	/*
	 * Obtain output semaphore if character will be echoed
	 */
	if (tty->termios.c_lflag & (ECHO|ECHOE|ECHOK|ECHONL|ECHOPRT|ECHOCTL|ECHOKE)) {
		rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
		i = iproc (c, tty);
		rtems_semaphore_release (tty->osem);
	}
	else {
		i = iproc (c, tty);
	}
	return i;
}

/*
 * Fill the input buffer by polling the device
 */
static rtems_status_code
fillBufferPoll (struct rtems_termios_tty *tty)
{
	int n;

	if (tty->termios.c_lflag & ICANON) {
		for (;;) {
			n = (*tty->device.pollRead)(tty->minor);
			if (n < 0) {
				rtems_task_wake_after (1);
			}
			else {
				if  (siproc (n, tty))
					break;
			}
		}
	}
	else {
		rtems_interval then, now;
		if (!tty->termios.c_cc[VMIN] && tty->termios.c_cc[VTIME])
			rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &then);
		for (;;) {
			n = (*tty->device.pollRead)(tty->minor);
			if (n < 0) {
				if (tty->termios.c_cc[VMIN]) {
					if (tty->termios.c_cc[VTIME] && tty->ccount) {
						rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &now);
						if ((now - then) > tty->vtimeTicks) {
							break;
						}
					}
				}
				else {
					if (!tty->termios.c_cc[VTIME])
						break;
					rtems_clock_get (RTEMS_CLOCK_GET_TICKS_SINCE_BOOT, &now);
					if ((now - then) > tty->vtimeTicks) {
						break;