/* Hey EMACS -*- linux-c -*- */
/* $Id: dev_link.c 1494 2005-07-30 14:41:25Z roms $ */

/*  libticables - Ti Link Cable library, a part of the TiLP project
 *  Copyright (C) 1999-2004  Romain Lievin
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* Linux tidev device driver support
 * Copyright (c) 2000 Leonard Stiles <ljs@uk2.net> 
 */

/* I have modified this module so that it can support the new functionnalities
 * that bring about my kernel modules (tipar & tiser modules).
 * But, it still support the 'tidev' kernel module.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>

#ifdef HAVE_LINUX_TICABLE_H
# include <linux/ticable.h>
# include <sys/ioctl.h>
#endif

#include "gettext.h"
#include "export.h"
#include "cabl_err.h"
#include "cabl_def.h"
#include "externs.h"
#include "timeout.h"
#include "export.h"
#include "printl.h"
#include "logging.h"

extern const char *ti_dev_file;

static int dev_fd = 0;

static struct cs {
  	uint8_t data;
  	int available;
} cs;

int dev_init()
{
  	int mask;

  	/* Init some internal variables */
  	cs.available = 0;
  	cs.data = 0;

  	/* Open the device */
  	mask = O_RDWR | /*O_NONBLOCK | */ O_SYNC;
  	if ((dev_fd = open(io_device, mask)) == -1) {
  		switch(errno) {
  		case ENODEV: printl1(2, _("unable to open character device: %s.\n"), io_device); break;
  		case EACCES: printl1(2, _("unable to open character device: %s (wrong permissions).\n"), io_device); break;
		default: printl1(2, _("unable to open character device: %s\n"), io_device); break;
		}
    	return ERR_OPEN_TIDEV;
	}

  	/* Set timeout and inter-bit delay */
#if defined(HAVE_LINUX_TICABLE_H)
	
	if((port == PARALLEL_PORT_1) || (port == PARALLEL_PORT_2) || (port == PARALLEL_PORT_3)) {
	  	if (ioctl(dev_fd, IOCTL_TIPAR_DELAY, delay) == -1) {
	    		printl1(2, _("failed to set delay.\n"));
	    		return ERR_IOCTL;
	  	}
	  	if (ioctl(dev_fd, IOCTL_TIPAR_TIMEOUT, time_out) == -1) {
	    		printl1(2, _("failed to set timeout.\n"));
	    		return ERR_IOCTL;
	  	}
	}
  	
  	if((port == SERIAL_PORT_1) || (port == SERIAL_PORT_2) || (port == SERIAL_PORT_3) || (port == SERIAL_PORT_4)) {
	  	if (ioctl(dev_fd, IOCTL_TISER_DELAY, delay) == -1) {
	    		printl1(2, _("failed to set delay.\n"));
	    		return ERR_IOCTL;
	  	}
	  	if (ioctl(dev_fd, IOCTL_TISER_TIMEOUT, time_out) == -1) {
	    		printl1(2, _("failed to set timeout.\n"));
	    		return ERR_IOCTL;
	  	}
	}
#endif

  	START_LOGGING();

  	return 0;
}

int dev_exit()
{
  	STOP_LOGGING();
  	if (dev_fd) {
    		close(dev_fd);
    		dev_fd = 0;
  	}

  	return 0;
}

int dev_open(void)
{
  	tdr.count = 0;
  	toSTART(tdr.start);

  	return 0;
}

int dev_close(void)
{
  	return 0;
}

int dev_put(uint8_t data)
{
  	int err;

  	tdr.count++;
  	LOG_DATA(data);
  	err = write(dev_fd, (void *) (&data), 1);
  	if (err <= 0) {
    		if (errno == ETIMEDOUT)
      		return ERR_WRITE_TIMEOUT;
    	else
      		return ERR_WRITE_ERROR;
  	}

  	return 0;
}

int dev_get(uint8_t * data)
{
  	int err = 0;

  	tdr.count++;
  	/* If the dev_check function was previously called, retrieve the uint8_t */
  	if (cs.available) {
    		*data = cs.data;
    		cs.available = 0;
    		return 0;
  	}

  	err = read(dev_fd, (void *) data, 1);
  	if (err <= 0) {
    		if (errno == ETIMEDOUT)
      			return ERR_READ_TIMEOUT;
    		else
      			return ERR_READ_ERROR;
  	}
  	LOG_DATA(*data);

  	return 0;
}

int dev_check(int *status)
{
  	int n = 0;

  	/* Since the select function does not work, I do it myself ! */
  	*status = STATUS_NONE;
  	if (dev_fd) {
    		n = read(dev_fd, (void *) (&cs.data), 1);
    		if (n > 0) {
      			if (cs.available == 1)
				return ERR_BYTE_LOST;

      			cs.available = 1;
      			*status = STATUS_RX;
      			return 0;
    		} else {
      			*status = STATUS_NONE;
      			return 0;
    		}
  	}

  	return 0;
}

int dev_probe(void)
{
  	return 0;
}

int dev_supported()
{
#if defined(HAVE_LINUX_TICABLE_H)
  	return SUPPORT_ON | SUPPORT_TIPAR | SUPPORT_TISER;
#else
  	return SUPPORT_ON;
#endif
}

int dev_reset()
{
	return 0;
}

int dev_register_cable(TicableLinkCable * lc)
{
  lc->init = dev_init;
  lc->open = dev_open;
  lc->put = dev_put;
  lc->get = dev_get;
  lc->close = dev_close;
  lc->exit = dev_exit;
  lc->probe = dev_probe;
  lc->check = dev_check;
  lc->reset = dev_reset;

  return 0;
}