master/pdo_entry.c
author Florian Pose <fp@igh-essen.com>
Tue, 01 Jun 2010 22:51:51 +0200
changeset 1935 8ea1033bd4c2
parent 1363 11c0b2caa253
child 2421 bc2d4bf9cbe5
permissions -rw-r--r--
Fixed NULL pointer dereference on request error in RTAI example.
/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH
 *
 *  This file is part of the IgH EtherCAT Master.
 *
 *  The IgH EtherCAT Master is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version 2, as
 *  published by the Free Software Foundation.
 *
 *  The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *  ---
 *
 *  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.
 *
 *****************************************************************************/

/**
   \file
   EtherCAT process data object entry methods.
*/

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

#include <linux/slab.h>

#include "pdo_entry.h"

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

/** PDO entry constructor.
 */
void ec_pdo_entry_init(
        ec_pdo_entry_t *entry /**< PDO entry. */
        )
{
    entry->name = NULL;
}

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

/** PDO entry copy constructor.
 *
 * \retval  0 Success.
 * \retval <0 Error code.
 */
int ec_pdo_entry_init_copy(
        ec_pdo_entry_t *entry, /**< PDO entry. */
        const ec_pdo_entry_t *other /**< PDO entry to copy from. */
        )
{
    entry->index = other->index;
    entry->subindex = other->subindex;
    entry->name = NULL;
    entry->bit_length = other->bit_length;

    return ec_pdo_entry_set_name(entry, other->name);
}

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

/** PDO entry destructor.
 */
void ec_pdo_entry_clear(ec_pdo_entry_t *entry /**< PDO entry. */)
{
    if (entry->name)
        kfree(entry->name);
}

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

/** Set PDO entry name.
 *
 * \retval  0 Success.
 * \retval <0 Error code.
 */
int ec_pdo_entry_set_name(
        ec_pdo_entry_t *entry, /**< PDO entry. */
        const char *name /**< New name. */
        )
{
    unsigned int len;

    if (entry->name && name && !strcmp(entry->name, name))
        return 0;
    
    if (entry->name)
        kfree(entry->name);

    if (name && (len = strlen(name))) {
        if (!(entry->name = (char *) kmalloc(len + 1, GFP_KERNEL))) {
            EC_ERR("Failed to allocate PDO entry name.\n");
            return -ENOMEM;
        }
        memcpy(entry->name, name, len + 1);
    } else {
        entry->name = NULL;
    }

    return 0;
}

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

/** Compares two PDO entries.
 *
 * \retval 1 The entries are equal.
 * \retval 0 The entries differ.
 */
int ec_pdo_entry_equal(
        const ec_pdo_entry_t *entry1, /**< First PDO entry. */
        const ec_pdo_entry_t *entry2 /**< Second PDO entry. */
        )
{
    return entry1->index == entry2->index
        && entry1->subindex == entry2->subindex
        && entry1->bit_length == entry2->bit_length;
}

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