lib/common.c
author Florian Pose <fp@igh-essen.com>
Mon, 17 Nov 2008 17:18:02 +0000
changeset 1313 ed15eef57d5c
parent 1287 cc7b679c74e9
child 1326 ef907b0b5125
permissions -rw-r--r--
Improved error case return codes of many functions.
/******************************************************************************
 *  
 * $Id$
 * 
 * Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH
 * 
 * This file is part of the IgH EtherCAT master userspace library.
 * 
 * The IgH EtherCAT master userspace library is free software; you can
 * redistribute it and/or modify it under the terms of the GNU Lesser General
 * Public License as published by the Free Software Foundation; version 2.1 of
 * the License.
 *
 * The IgH EtherCAT master userspace library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the IgH EtherCAT master userspace library. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The right to use EtherCAT Technology is granted and comes free of charge
 * under condition of compatibility of product made by Licensee. People
 * intending to distribute/sell products based on the code, have to sign an
 * agreement to guarantee that products using software based on IgH EtherCAT
 * master stay compatible with the actual EtherCAT specification (which are
 * released themselves as an open standard) as the (only) precondition to have
 * the right to use EtherCAT Technology, IP and trade marks.
 *
 *****************************************************************************/

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>

#include "master.h"
#include "master/ioctl.h"

/*****************************************************************************/

unsigned int ecrt_version_magic(void)
{
    return ECRT_VERSION_MAGIC;
}

/*****************************************************************************/

#define MAX_PATH_LEN 64

ec_master_t *ecrt_request_master(unsigned int master_index)
{
    char path[MAX_PATH_LEN];
    ec_master_t *master;

    master = malloc(sizeof(ec_master_t));
    if (!master) {
        fprintf(stderr, "Failed to allocate memory.\n");
        return 0;
    }

    master->process_data = NULL;
    master->process_data_size = 0;

    snprintf(path, MAX_PATH_LEN - 1, "/dev/EtherCAT%u", master_index);

    master->fd = open(path, O_RDWR);
    if (master->fd == -1) {
        fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
        free(master);
        return 0;
    }

    if (ioctl(master->fd, EC_IOCTL_REQUEST, NULL) == -1) {
        fprintf(stderr, "Failed to request master %u: %s\n",
                master_index, strerror(errno));
        close(master->fd);
        free(master);
        return 0; 
    }

    return master;
}

/*****************************************************************************/

void ecrt_release_master(ec_master_t *master)
{
    if (master->process_data)  {
        munmap(master->process_data, master->process_data_size);
    }

    close(master->fd);
    free(master);
}

/*****************************************************************************/