/******************************************************************************
 *  
 *  $Id$
 * 
 *  Copyright (C) 2006-2009  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 license mentioned above concerns the source code only. Using the
 *  EtherCAT technology and brand is only permitted in compliance with the
 *  industrial property and similar rights of Beckhoff Automation GmbH.
 *
 *****************************************************************************/

#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;
}

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

ec_master_t *ecrt_request_master(unsigned int master_index)
{
    ec_master_t *master = ecrt_open_master(master_index);
    if (master) {
        if (ecrt_master_reserve(master) < 0) {
            close(master->fd);
            free(master);
            master = 0;
        }
    }

    return master;
}

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

#define MAX_PATH_LEN 64

ec_master_t *ecrt_open_master(unsigned int master_index)
{
    char path[MAX_PATH_LEN];
    ec_master_t *master = NULL;
    ec_ioctl_module_t module_data;

    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));
        goto out_free;
    }

    if (ioctl(master->fd, EC_IOCTL_MODULE, &module_data) < 0) {
        fprintf(stderr, "Failed to get module information from %s: %s\n",
                path, strerror(errno));
        goto out_close;
    }

    if (module_data.ioctl_version_magic != EC_IOCTL_VERSION_MAGIC) {
        fprintf(stderr, "ioctl() version magic is differing:"
                " %s: %u, libethercat: %u.\n",
                path, module_data.ioctl_version_magic,
                EC_IOCTL_VERSION_MAGIC);
        goto out_close;
    }

    return master;

out_close:
    close(master->fd);
out_free:
    free(master);
    return 0;
}

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

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);
}

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