diff -r 63bef67e812b -r fdb85a806585 master/datagram_pair.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/master/datagram_pair.c	Thu Sep 06 18:28:57 2012 +0200
@@ -0,0 +1,173 @@
+/******************************************************************************
+ *
+ *  $Id$
+ *
+ *  Copyright (C) 2006-2012  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 datagram pair methods.
+*/
+
+/*****************************************************************************/
+
+#include <linux/slab.h>
+
+#include "master.h"
+#include "datagram_pair.h"
+
+/*****************************************************************************/
+
+/** Datagram pair constructor.
+ */
+int ec_datagram_pair_init(
+        ec_datagram_pair_t *pair, /**< Datagram pair. */
+        ec_domain_t *domain, /**< Parent domain. */
+        uint32_t logical_offset,
+        uint8_t *data,
+        size_t data_size, /**< Data size. */
+        const unsigned int used[] /**< input/output use count. */
+        )
+{
+    ec_device_index_t dev_idx;
+    int ret;
+
+    INIT_LIST_HEAD(&pair->list);
+    pair->domain = domain;
+
+    for (dev_idx = EC_DEVICE_MAIN; dev_idx < EC_NUM_DEVICES; dev_idx++) {
+        ec_datagram_init(&pair->datagrams[dev_idx]);
+        snprintf(pair->datagrams[dev_idx].name,
+                EC_DATAGRAM_NAME_SIZE, "domain%u-%u-%s", domain->index,
+                logical_offset, ec_device_names[dev_idx]);
+        pair->datagrams[dev_idx].device_index = dev_idx;
+    }
+
+    pair->expected_working_counter = 0U;
+
+    /* backup datagram has its own memory */
+    ret = ec_datagram_prealloc(&pair->datagrams[EC_DEVICE_BACKUP],
+            data_size);
+    if (ret) {
+        goto out_datagrams;
+    }
+
+    if (!(pair->send_buffer = kmalloc(data_size, GFP_KERNEL))) {
+        EC_MASTER_ERR(domain->master,
+                "Failed to allocate domain send buffer!\n");
+        ret = -ENOMEM;
+        goto out_datagrams;
+    }
+
+    /* The ec_datagram_lxx() calls below can not fail, because either the
+     * datagram has external memory or it is preallocated. */
+
+    if (used[EC_DIR_OUTPUT] && used[EC_DIR_INPUT]) { // inputs and outputs
+        ec_datagram_lrw_ext(&pair->datagrams[EC_DEVICE_MAIN],
+                logical_offset, data_size, data);
+        ec_datagram_lrw(&pair->datagrams[EC_DEVICE_BACKUP],
+                logical_offset, data_size);
+
+        // If LRW is used, output FMMUs increment the working counter by 2,
+        // while input FMMUs increment it by 1.
+        pair->expected_working_counter =
+            used[EC_DIR_OUTPUT] * 2 + used[EC_DIR_INPUT];
+    } else if (used[EC_DIR_OUTPUT]) { // outputs only
+        ec_datagram_lwr_ext(&pair->datagrams[EC_DEVICE_MAIN],
+                logical_offset, data_size, data);
+        ec_datagram_lwr(&pair->datagrams[EC_DEVICE_BACKUP],
+                logical_offset, data_size);
+
+        pair->expected_working_counter = used[EC_DIR_OUTPUT];
+    } else { // inputs only (or nothing)
+        ec_datagram_lrd_ext(&pair->datagrams[EC_DEVICE_MAIN],
+                logical_offset, data_size, data);
+        ec_datagram_lrd(&pair->datagrams[EC_DEVICE_BACKUP],
+                logical_offset, data_size);
+
+        pair->expected_working_counter = used[EC_DIR_INPUT];
+    }
+
+    for (dev_idx = 0; dev_idx < EC_NUM_DEVICES; dev_idx++) {
+        ec_datagram_zero(&pair->datagrams[dev_idx]);
+    }
+
+    return 0;
+
+out_datagrams:
+    for (dev_idx = 0; dev_idx < EC_NUM_DEVICES; dev_idx++) {
+        ec_datagram_clear(&pair->datagrams[dev_idx]);
+    }
+
+    return ret;
+}
+
+/*****************************************************************************/
+
+/** Datagram pair destructor.
+ */
+void ec_datagram_pair_clear(
+        ec_datagram_pair_t *pair /**< Datagram pair. */
+        )
+{
+    unsigned int dev_idx;
+
+    for (dev_idx = 0; dev_idx < EC_NUM_DEVICES; dev_idx++) {
+        ec_datagram_clear(&pair->datagrams[dev_idx]);
+    }
+
+    if (pair->send_buffer) {
+        kfree(pair->send_buffer);
+    }
+}
+
+/*****************************************************************************/
+
+/** Process received data.
+ */
+uint16_t ec_datagram_pair_process(
+        ec_datagram_pair_t *pair, /**< Datagram pair. */
+        uint16_t wc_sum[EC_NUM_DEVICES] /**< Working counter sums. */
+        )
+{
+    unsigned int dev_idx;
+    uint16_t pair_wc = 0;
+
+    for (dev_idx = 0; dev_idx < EC_NUM_DEVICES; dev_idx++) {
+        ec_datagram_t *datagram = &pair->datagrams[dev_idx];
+
+        ec_datagram_output_stats(datagram);
+
+        if (datagram->state == EC_DATAGRAM_RECEIVED) {
+            pair_wc += datagram->working_counter;
+            wc_sum[dev_idx] += datagram->working_counter;
+        }
+    }
+
+    return pair_wc;
+}
+
+/*****************************************************************************/