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/* tty.c -- Definition of functions for peripheral to

 * communicate with host via a tty.

   Copyright (C) 2002 Richard Prescott <rip@step.polymtl.ca>

   Copyright (C) 2008 Embecosm Limited

   Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>

   This file is part of Or1ksim, the OpenRISC 1000 Architectural Simulator.

   This program is free software; you can redistribute it and/or modify it

   under the terms of the GNU General Public License as published by the Free

   Software Foundation; either version 3 of the License, or (at your option)

   any later version.

   This program is distributed in the hope that it will be useful, but WITHOUT

   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

   more details.

   You should have received a copy of the GNU General Public License along

   with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* This program is commented throughout in a fashion suitable for processing

   with Doxygen. */

/* Autoconf and/or portability configuration */

#include "config.h"

#include "port.h"

/* System includes */

#include <stdlib.h>

#include <unistd.h>

#include <termios.h>

#include <stdio.h>

#include <fcntl.h>

/* Package includes */

#include "channel.h"

#include "generic.h"

#include "fd.h"

/* Default parameters if not specified in config file */

#define DEFAULT_BAUD        B19200

#define DEFAULT_TTY_DEVICE  "/dev/ttyS0"

/*! Data structure representing a TTY channel */

struct tty_channel

{

  struct fd_channel fds;

};

/*! Table of Baud rates */

static const struct

{

  char *name;

  int value;

} baud_table[] =

{

  {

  "50", B50},

  {

  "2400", B2400},

  {

  "4800", B4800},

  {

  "9600", B9600},

  {

  "19200", B19200},

  {

  "38400", B38400},

  {

  "115200", B115200},

  {

  "230400", B230400},

  {

  0, 0}

};

/* Forward declaration of static functions */

static void *tty_init (const char *input);

static int   tty_open (void *data);

/*! Global data structure representing the operations on a TTY channel */

struct channel_ops tty_channel_ops = {

        .init  = tty_init,

        .open  = tty_open,

        .close = generic_close,

        .read  = fd_read,

        .write = fd_write,

        .free  = generic_free,

};

/* Convert baud rate string to termio baud rate constant */

static int

parse_baud (char *baud_string)

{

  int i;

  for (i = 0; baud_table[i].name; i++)

    {

      if (!strcmp (baud_table[i].name, baud_string))

        return baud_table[i].value;

    }

  fprintf (stderr, "Error: unknown baud rate: %s\n", baud_string);

  fprintf (stderr, "       Known baud rates: ");

  for (i = 0; baud_table[i].name; i++)

    {

      fprintf (stderr, "%s%s", baud_table[i].name,

               baud_table[i + 1].name ? ", " : "\n");

    }

  return B0;

}

static void *

tty_init (const char *input)

{

  int fd = 0, baud;

  char *param_name, *param_value, *device;

  struct termios options;

  struct tty_channel *channel;

  channel = (struct tty_channel *) malloc (sizeof (struct tty_channel));

  if (!channel)

    return NULL;

  /* Make a copy of config string, because we're about to mutate it */

  input = strdup (input);

  if (!input)

    goto error;

  baud = DEFAULT_BAUD;

  device = DEFAULT_TTY_DEVICE;

  /* Parse command-line parameters

     Command line looks like name1=value1,name2,name3=value3,... */

  while ((param_name = strtok ((char *) input, ",")))

    {

      input = NULL;

      /* Parse a parameter's name and value */

      param_value = strchr (param_name, '=');

      if (param_value != NULL)

        {

          *param_value = '\0';

          param_value++;        /* Advance past '=' character */

        }

      if (!strcmp (param_name, "baud") && param_value)

        {

          baud = parse_baud (param_value);

          if (baud == B0)

            {

              goto error;

            }

        }

      else if (!strcmp (param_name, "device"))

        {

          device = param_value;

        }

      else

        {

          fprintf (stderr, "error: unknown tty channel parameter \"%s\"\n",

                   param_name);

          goto error;

        }

    }

  fd = open (device, O_RDWR);

  if (fd < 0)

    goto error;

  /* Get the current options for the port... */

  if (tcgetattr (fd, &options) < 0)

    goto error;

  /* Set the serial baud rate */

  cfsetispeed (&options, baud);

  cfsetospeed (&options, baud);

  /* Enable the receiver and set local mode... */

  /* cfmakeraw(&options);

   *

   * cygwin lacks cfmakeraw(), just do it explicitly

   */

  options.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP

                       | INLCR | IGNCR | ICRNL | IXON);

  options.c_oflag &= ~OPOST;

  options.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);

  options.c_cflag &= ~(CSIZE | PARENB);

  options.c_cflag |= CS8;

  options.c_cflag |= (CLOCAL | CREAD);

  /* Set the new options for the port... */

  if (tcsetattr (fd, TCSANOW, &options) < 0)

    goto error;

  channel->fds.fdin = channel->fds.fdout = fd;

  free ((void *) input);

  return channel;

error:

  if (fd > 0)

    close (fd);

  free (channel);

  if (input)

    free ((void *) input);

  return NULL;

}

static int

tty_open (void *data)

{

  return 0;

}