fp@2438: /******************************************************************************
fp@2438:  *
fp@2438:  *  $Id$
fp@2438:  *
fp@2438:  *  Copyright (C) 2012  Florian Pose, Ingenieurgemeinschaft IgH
fp@2438:  *
fp@2438:  *  This file is part of the IgH EtherCAT Master.
fp@2438:  *
fp@2438:  *  The IgH EtherCAT Master is free software; you can redistribute it and/or
fp@2438:  *  modify it under the terms of the GNU General Public License version 2, as
fp@2438:  *  published by the Free Software Foundation.
fp@2438:  *
fp@2438:  *  The IgH EtherCAT Master is distributed in the hope that it will be useful,
fp@2438:  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
fp@2438:  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
fp@2438:  *  Public License for more details.
fp@2438:  *
fp@2438:  *  You should have received a copy of the GNU General Public License along
fp@2438:  *  with the IgH EtherCAT Master; if not, write to the Free Software
fp@2438:  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
fp@2438:  *
fp@2438:  *  ---
fp@2438:  *
fp@2438:  *  The license mentioned above concerns the source code only. Using the
fp@2438:  *  EtherCAT technology and brand is only permitted in compliance with the
fp@2438:  *  industrial property and similar rights of Beckhoff Automation GmbH.
fp@2438:  *
fp@2438:  *  vim: expandtab
fp@2438:  *
fp@2438:  *****************************************************************************/
fp@2438: 
fp@2522: /** \file
fp@2522:  * EtherCAT CoE emergency ring buffer methods.
fp@2522:  */
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: #include <linux/slab.h>
fp@2438: 
fp@2438: #include "coe_emerg_ring.h"
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Emergency ring buffer constructor.
fp@2438:  */
fp@2438: void ec_coe_emerg_ring_init(
fp@2438:         ec_coe_emerg_ring_t *ring, /**< Emergency ring. */
fp@2438:         ec_slave_config_t *sc /**< Slave configuration. */
fp@2438:         )
fp@2438: {
fp@2438:     ring->sc = sc;
fp@2438:     ring->msgs = NULL;
fp@2438:     ring->size = 0;
fp@2438:     ring->read_index = 0;
fp@2438:     ring->write_index = 0;
fp@2438:     ring->overruns = 0;
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Emergency ring buffer destructor.
fp@2438:  */
fp@2438: void ec_coe_emerg_ring_clear(
fp@2438:         ec_coe_emerg_ring_t *ring /**< Emergency ring. */
fp@2438:         )
fp@2438: {
fp@2438:     if (ring->msgs) {
fp@2438:         kfree(ring->msgs);
fp@2438:     }
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Set the ring size.
fp@2522:  *
fp@2522:  * \return Zero on success, otherwise a negative error code.
fp@2438:  */
fp@2438: int ec_coe_emerg_ring_size(
fp@2438:         ec_coe_emerg_ring_t *ring, /**< Emergency ring. */
fp@2438:         size_t size /**< Maximum number of messages in the ring. */
fp@2438:         )
fp@2438: {
fp@2438:     ring->size = 0;
fp@2438: 
fp@2438:     if (size < 0) {
fp@2438:         size = 0;
fp@2438:     }
fp@2438: 
fp@2438:     ring->read_index = ring->write_index = 0;
fp@2438: 
fp@2438:     if (ring->msgs) {
fp@2438:         kfree(ring->msgs);
fp@2438:     }
fp@2438:     ring->msgs = NULL;
fp@2438: 
fp@2438:     if (size == 0) {
fp@2438:         return 0;
fp@2438:     }
fp@2438: 
fp@2438:     ring->msgs = kmalloc(sizeof(ec_coe_emerg_msg_t) * (size + 1), GFP_KERNEL);
fp@2438:     if (!ring->msgs) {
fp@2438:         return -ENOMEM;
fp@2438:     }
fp@2438: 
fp@2438:     ring->size = size;
fp@2438:     return 0;
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Add a new emergency message.
fp@2438:  */
fp@2438: void ec_coe_emerg_ring_push(
fp@2438:         ec_coe_emerg_ring_t *ring, /**< Emergency ring. */
fp@2438:         const u8 *msg /**< Emergency message. */
fp@2438:         )
fp@2438: {
fp@2438:     if (!ring->size ||
fp@2438:             (ring->write_index + 1) % (ring->size + 1) == ring->read_index) {
fp@2438:         ring->overruns++;
fp@2438:         return;
fp@2438:     }
fp@2438: 
fp@2438:     memcpy(ring->msgs[ring->write_index].data, msg,
fp@2438:             EC_COE_EMERGENCY_MSG_SIZE);
fp@2438:     ring->write_index = (ring->write_index + 1) % (ring->size + 1);
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Remove an emergency message from the ring.
fp@2522:  *
fp@2522:  * \return Zero on success, otherwise a negative error code.
fp@2438:  */
fp@2438: int ec_coe_emerg_ring_pop(
fp@2438:         ec_coe_emerg_ring_t *ring, /**< Emergency ring. */
fp@2438:         u8 *msg /**< Memory to store the emergency message. */
fp@2438:         )
fp@2438: {
fp@2438:     if (ring->read_index == ring->write_index) {
fp@2438:         return -ENOENT;
fp@2438:     }
fp@2438: 
fp@2438:     memcpy(msg, ring->msgs[ring->read_index].data, EC_COE_EMERGENCY_MSG_SIZE);
fp@2438:     ring->read_index = (ring->read_index + 1) % (ring->size + 1);
fp@2438:     return 0;
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Clear the ring.
fp@2522:  *
fp@2522:  * \return Zero on success, otherwise a negative error code.
fp@2438:  */
fp@2438: int ec_coe_emerg_ring_clear_ring(
fp@2438:         ec_coe_emerg_ring_t *ring /**< Emergency ring. */
fp@2438:         )
fp@2438: {
fp@2438:     ring->read_index = ring->write_index;
fp@2438:     ring->overruns = 0;
fp@2438:     return 0;
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/
fp@2438: 
fp@2438: /** Read the number of overruns.
fp@2522:  *
fp@2522:  * \return Number of overruns.
fp@2438:  */
fp@2438: int ec_coe_emerg_ring_overruns(
fp@2438:         ec_coe_emerg_ring_t *ring /**< Emergency ring. */
fp@2438:         )
fp@2438: {
fp@2438:     return ring->overruns;
fp@2438: }
fp@2438: 
fp@2438: /*****************************************************************************/