master/master.c
author Florian Pose <fp@igh-essen.com>
Thu, 13 Mar 2008 12:42:48 +0000
changeset 868 aaf175ef0171
parent 861 6e3de145421a
child 872 d4e0380d63b3
permissions -rw-r--r--
Added documentation.
/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006  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
 *  as published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version.
 *
 *  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 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.
 *
 *****************************************************************************/

/**
   \file
   EtherCAT master methods.
*/

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

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/delay.h>

#include "../include/ecrt.h"
#include "globals.h"
#include "slave.h"
#include "slave_config.h"
#include "device.h"
#include "datagram.h"
#ifdef EC_EOE
#include "ethernet.h"
#endif
#include "master.h"

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

void ec_master_destroy_slave_configs(ec_master_t *);
void ec_master_destroy_domains(ec_master_t *);
static int ec_master_idle_thread(ec_master_t *);
static int ec_master_operation_thread(ec_master_t *);
#ifdef EC_EOE
void ec_master_eoe_run(unsigned long);
#endif
ssize_t ec_show_master_attribute(struct kobject *, struct attribute *, char *);
ssize_t ec_store_master_attribute(struct kobject *, struct attribute *,
                                  const char *, size_t);

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

/** \cond */

EC_SYSFS_READ_ATTR(info);
EC_SYSFS_READ_WRITE_ATTR(debug_level);

static struct attribute *ec_def_attrs[] = {
    &attr_info,
    &attr_debug_level,
    NULL,
};

static struct sysfs_ops ec_sysfs_ops = {
    .show = &ec_show_master_attribute,
    .store = ec_store_master_attribute
};

static struct kobj_type ktype_ec_master = {
    .release = NULL,
    .sysfs_ops = &ec_sysfs_ops,
    .default_attrs = ec_def_attrs
};

/** \endcond */

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

/**
   Master constructor.
   \return 0 in case of success, else < 0
*/

int ec_master_init(ec_master_t *master, /**< EtherCAT master */
        struct kobject *module_kobj, /**< kobject of the master module */
        unsigned int index, /**< master index */
        const uint8_t *main_mac, /**< MAC address of main device */
        const uint8_t *backup_mac /**< MAC address of backup device */
        )
{
    unsigned int i;

    master->index = index;
    master->reserved = 0;

    master->main_mac = main_mac;
    master->backup_mac = backup_mac;
    init_MUTEX(&master->device_sem);

    master->mode = EC_MASTER_MODE_ORPHANED;
    master->injection_seq_fsm = 0;
    master->injection_seq_rt = 0;

    INIT_LIST_HEAD(&master->slaves);
    master->slave_count = 0;
    
    INIT_LIST_HEAD(&master->configs);

    master->scan_state = EC_REQUEST_SUCCESS;
    master->allow_scan = 1;
    init_MUTEX(&master->scan_sem);
    init_waitqueue_head(&master->scan_queue);

    master->config_state = EC_REQUEST_SUCCESS;
    master->allow_config = 1;
    init_MUTEX(&master->config_sem);
    init_waitqueue_head(&master->config_queue);
    
    INIT_LIST_HEAD(&master->datagram_queue);
    master->datagram_index = 0;

    INIT_LIST_HEAD(&master->domains);

    master->debug_level = 0;
    master->stats.timeouts = 0;
    master->stats.corrupted = 0;
    master->stats.unmatched = 0;
    master->stats.output_jiffies = 0;
    master->pdo_slaves_offline = 0; // assume all Pdo slaves online
    master->frames_timed_out = 0;

    for (i = 0; i < HZ; i++) {
        master->idle_cycle_times[i] = 0;
#ifdef EC_EOE
        master->eoe_cycle_times[i] = 0;
#endif
    }
    master->idle_cycle_time_pos = 0;
#ifdef EC_EOE
    master->eoe_cycle_time_pos = 0;

    init_timer(&master->eoe_timer);
    master->eoe_timer.function = ec_master_eoe_run;
    master->eoe_timer.data = (unsigned long) master;
    master->eoe_running = 0;
    INIT_LIST_HEAD(&master->eoe_handlers);
#endif

    master->internal_lock = SPIN_LOCK_UNLOCKED;
    master->request_cb = NULL;
    master->release_cb = NULL;
    master->cb_data = NULL;

    INIT_LIST_HEAD(&master->eeprom_requests);
    init_MUTEX(&master->eeprom_sem);
    init_waitqueue_head(&master->eeprom_queue);

    INIT_LIST_HEAD(&master->slave_sdo_requests);
    init_MUTEX(&master->sdo_sem);
    init_waitqueue_head(&master->sdo_queue);

    // init devices
    if (ec_device_init(&master->main_device, master))
        goto out_return;

    if (ec_device_init(&master->backup_device, master))
        goto out_clear_main;

    // init state machine datagram
    ec_datagram_init(&master->fsm_datagram);
    snprintf(master->fsm_datagram.name, EC_DATAGRAM_NAME_SIZE, "master-fsm");
    if (ec_datagram_prealloc(&master->fsm_datagram, EC_MAX_DATA_SIZE)) {
        EC_ERR("Failed to allocate FSM datagram.\n");
        goto out_clear_backup;
    }

    // create state machine object
    ec_fsm_master_init(&master->fsm, master, &master->fsm_datagram);

    // init kobject and add it to the hierarchy
    memset(&master->kobj, 0x00, sizeof(struct kobject));
    kobject_init(&master->kobj);
    master->kobj.ktype = &ktype_ec_master;
    master->kobj.parent = module_kobj;
    
    if (kobject_set_name(&master->kobj, "master%i", index)) {
        EC_ERR("Failed to set master kobject name.\n");
        kobject_put(&master->kobj);
        goto out_clear_fsm;
    }
    
    if (kobject_add(&master->kobj)) {
        EC_ERR("Failed to add master kobject.\n");
        kobject_put(&master->kobj);
        goto out_clear_fsm;
    }

    return 0;

out_clear_fsm:
    ec_fsm_master_clear(&master->fsm);
out_clear_backup:
    ec_device_clear(&master->backup_device);
out_clear_main:
    ec_device_clear(&master->main_device);
out_return:
    return -1;
}

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

/**
   Clear and free master.
   This method is called by the kobject,
   once there are no more references to it.
*/

void ec_master_clear(
        ec_master_t *master /**< EtherCAT master */
        )
{
#ifdef EC_EOE
    ec_master_clear_eoe_handlers(master);
#endif
    ec_master_destroy_slave_configs(master);
    ec_master_destroy_slaves(master);
    ec_master_destroy_domains(master);
    ec_fsm_master_clear(&master->fsm);
    ec_datagram_clear(&master->fsm_datagram);
    ec_device_clear(&master->backup_device);
    ec_device_clear(&master->main_device);

    // destroy self
    kobject_del(&master->kobj);
    kobject_put(&master->kobj);
}

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

#ifdef EC_EOE
/** Clear and free all EoE handlers.
 */
void ec_master_clear_eoe_handlers(
        ec_master_t *master /**< EtherCAT master */
        )
{
    ec_eoe_t *eoe, *next;

    list_for_each_entry_safe(eoe, next, &master->eoe_handlers, list) {
        list_del(&eoe->list);
        ec_eoe_clear(eoe);
        kfree(eoe);
    }
}
#endif

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

/** Destroy all slave configurations.
 */
void ec_master_destroy_slave_configs(ec_master_t *master)
{
    ec_slave_config_t *sc, *next;

    list_for_each_entry_safe(sc, next, &master->configs, list) {
        list_del(&sc->list);
        ec_slave_config_destroy(sc);
    }
}

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

/** Destroy all slaves.
 */
void ec_master_destroy_slaves(ec_master_t *master)
{
    ec_slave_t *slave, *next;

    list_for_each_entry_safe(slave, next, &master->slaves, list) {
        list_del(&slave->list);
        ec_slave_destroy(slave);
    }

    master->slave_count = 0;
}

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

/**
   Destroy all domains.
*/

void ec_master_destroy_domains(ec_master_t *master)
{
    ec_domain_t *domain, *next;

    list_for_each_entry_safe(domain, next, &master->domains, list) {
        list_del(&domain->list);
        ec_domain_destroy(domain);
    }
}

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

/**
   Internal locking callback.
*/

int ec_master_request_cb(void *master /**< callback data */)
{
    spin_lock(&((ec_master_t *) master)->internal_lock);
    return 0;
}

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

/**
   Internal unlocking callback.
*/

void ec_master_release_cb(void *master /**< callback data */)
{
    spin_unlock(&((ec_master_t *) master)->internal_lock);
}

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

/**
 * Starts the master thread.
 */

int ec_master_thread_start(
        ec_master_t *master, /**< EtherCAT master */
        int (*thread_func)(ec_master_t *) /**< thread function to start */
        )
{
    init_completion(&master->thread_exit);

    EC_INFO("Starting master thread.\n");
    if (!(master->thread_id = kernel_thread((int (*)(void *)) thread_func,
                    master, CLONE_KERNEL)))
        return -1;
    
    return 0;
}

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

/**
 * Stops the master thread.
 */

void ec_master_thread_stop(ec_master_t *master /**< EtherCAT master */)
{
    if (!master->thread_id) {
        EC_WARN("ec_master_thread_stop: Already finished!\n");
        return;
    }

    kill_proc(master->thread_id, SIGTERM, 1);
    wait_for_completion(&master->thread_exit);
    EC_INFO("Master thread exited.\n");

    if (master->fsm_datagram.state != EC_DATAGRAM_SENT) return;
    
    // wait for FSM datagram
    while (get_cycles() - master->fsm_datagram.cycles_sent
            < (cycles_t) EC_IO_TIMEOUT /* us */ * (cpu_khz / 1000))
        schedule();
}

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

/**
 * Transition function from ORPHANED to IDLE mode.
 */

int ec_master_enter_idle_mode(ec_master_t *master /**< EtherCAT master */)
{
    master->request_cb = ec_master_request_cb;
    master->release_cb = ec_master_release_cb;
    master->cb_data = master;

    master->mode = EC_MASTER_MODE_IDLE;
    if (ec_master_thread_start(master, ec_master_idle_thread)) {
        master->mode = EC_MASTER_MODE_ORPHANED;
        return -1;
    }

    return 0;
}

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

/**
 * Transition function from IDLE to ORPHANED mode.
 */

void ec_master_leave_idle_mode(ec_master_t *master /**< EtherCAT master */)
{
    master->mode = EC_MASTER_MODE_ORPHANED;
    
#ifdef EC_EOE
    ec_master_eoe_stop(master);
#endif
    ec_master_thread_stop(master);
    ec_master_destroy_slaves(master);
}

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

/**
 * Transition function from IDLE to OPERATION mode.
 */

int ec_master_enter_operation_mode(ec_master_t *master /**< EtherCAT master */)
{
    ec_slave_t *slave;
#ifdef EC_EOE
    ec_eoe_t *eoe;
#endif

    down(&master->config_sem);
    master->allow_config = 0; // temporarily disable slave configuration
    up(&master->config_sem);

    // wait for slave configuration to complete
    if (wait_event_interruptible(master->config_queue,
                master->config_state != EC_REQUEST_BUSY)) {
        EC_INFO("Finishing slave configuration interrupted by signal.\n");
        goto out_allow;
    }

    if (master->debug_level)
        EC_DBG("Waiting for pending slave configuration returned.\n");

    if (master->debug_level)
        EC_DBG("Disable scanning, current scan state: %u\n",
                master->scan_state);
    down(&master->scan_sem);
    master->allow_scan = 0; // 'lock' the slave list
    up(&master->scan_sem);

    if (master->scan_state == EC_REQUEST_BUSY) {
        // wait for slave scan to complete
        if (wait_event_interruptible(master->scan_queue,
                    master->scan_state != EC_REQUEST_BUSY)) {
            EC_INFO("Waiting for slave scan interrupted by signal.\n");
            goto out_allow;
        }
    }

    if (master->debug_level)
        EC_DBG("Waiting for pending slave scan returned.\n");

    // set states for all slaves
    list_for_each_entry(slave, &master->slaves, list) {
        ec_slave_request_state(slave, EC_SLAVE_STATE_PREOP);
    }
#ifdef EC_EOE
    // ... but set EoE slaves to OP
    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        if (ec_eoe_is_open(eoe))
            ec_slave_request_state(eoe->slave, EC_SLAVE_STATE_OP);
    }
#endif

    if (master->debug_level)
        EC_DBG("Switching to operation mode.\n");

    master->mode = EC_MASTER_MODE_OPERATION;
    master->ext_request_cb = NULL;
    master->ext_release_cb = NULL;
    master->ext_cb_data = NULL;
    return 0;
    
out_allow:
    master->allow_scan = 1;
    master->allow_config = 1;
    return -1;
}

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

/**
 * Transition function from OPERATION to IDLE mode.
 */

void ec_master_leave_operation_mode(ec_master_t *master
                                    /**< EtherCAT master */)
{
    ec_slave_t *slave;
#ifdef EC_EOE
    ec_eoe_t *eoe;
#endif

    master->mode = EC_MASTER_MODE_IDLE;

#ifdef EC_EOE
    ec_master_eoe_stop(master);
#endif
    ec_master_thread_stop(master);
    
    master->request_cb = ec_master_request_cb;
    master->release_cb = ec_master_release_cb;
    master->cb_data = master;
    
    ec_master_destroy_slave_configs(master);
    ec_master_destroy_domains(master);

    // set states for all slaves
    list_for_each_entry(slave, &master->slaves, list) {
        ec_slave_request_state(slave, EC_SLAVE_STATE_PREOP);
    }
#ifdef EC_EOE
    // ... but leave EoE slaves in OP
    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        if (ec_eoe_is_open(eoe))
            ec_slave_request_state(eoe->slave, EC_SLAVE_STATE_OP);
    }
#endif

    if (ec_master_thread_start(master, ec_master_idle_thread))
        EC_WARN("Failed to restart master thread!\n");
#ifdef EC_EOE
    ec_master_eoe_start(master);
#endif

    master->allow_scan = 1;
    master->allow_config = 1;
}

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

/**
   Places a datagram in the datagram queue.
*/

void ec_master_queue_datagram(ec_master_t *master, /**< EtherCAT master */
                              ec_datagram_t *datagram /**< datagram */
                              )
{
    ec_datagram_t *queued_datagram;

    // check, if the datagram is already queued
    list_for_each_entry(queued_datagram, &master->datagram_queue, queue) {
        if (queued_datagram == datagram) {
            datagram->skip_count++;
            if (master->debug_level)
                EC_DBG("skipping datagram %x.\n", (unsigned int) datagram);
            datagram->state = EC_DATAGRAM_QUEUED;
            return;
        }
    }

    list_add_tail(&datagram->queue, &master->datagram_queue);
    datagram->state = EC_DATAGRAM_QUEUED;
}

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

/**
   Sends the datagrams in the queue.
   \return 0 in case of success, else < 0
*/

void ec_master_send_datagrams(ec_master_t *master /**< EtherCAT master */)
{
    ec_datagram_t *datagram, *next;
    size_t datagram_size;
    uint8_t *frame_data, *cur_data;
    void *follows_word;
    cycles_t cycles_start, cycles_sent, cycles_end;
    unsigned long jiffies_sent;
    unsigned int frame_count, more_datagrams_waiting;
    struct list_head sent_datagrams;

    cycles_start = get_cycles();
    frame_count = 0;
    INIT_LIST_HEAD(&sent_datagrams);

    if (unlikely(master->debug_level > 1))
        EC_DBG("ec_master_send_datagrams\n");

    do {
        // fetch pointer to transmit socket buffer
        frame_data = ec_device_tx_data(&master->main_device);
        cur_data = frame_data + EC_FRAME_HEADER_SIZE;
        follows_word = NULL;
        more_datagrams_waiting = 0;

        // fill current frame with datagrams
        list_for_each_entry(datagram, &master->datagram_queue, queue) {
            if (datagram->state != EC_DATAGRAM_QUEUED) continue;

            // does the current datagram fit in the frame?
            datagram_size = EC_DATAGRAM_HEADER_SIZE + datagram->data_size
                + EC_DATAGRAM_FOOTER_SIZE;
            if (cur_data - frame_data + datagram_size > ETH_DATA_LEN) {
                more_datagrams_waiting = 1;
                break;
            }

            list_add_tail(&datagram->sent, &sent_datagrams);
            datagram->index = master->datagram_index++;

            if (unlikely(master->debug_level > 1))
                EC_DBG("adding datagram 0x%02X\n", datagram->index);

            // set "datagram following" flag in previous frame
            if (follows_word)
                EC_WRITE_U16(follows_word, EC_READ_U16(follows_word) | 0x8000);

            // EtherCAT datagram header
            EC_WRITE_U8 (cur_data,     datagram->type);
            EC_WRITE_U8 (cur_data + 1, datagram->index);
            memcpy(cur_data + 2, datagram->address, EC_ADDR_LEN);
            EC_WRITE_U16(cur_data + 6, datagram->data_size & 0x7FF);
            EC_WRITE_U16(cur_data + 8, 0x0000);
            follows_word = cur_data + 6;
            cur_data += EC_DATAGRAM_HEADER_SIZE;

            // EtherCAT datagram data
            memcpy(cur_data, datagram->data, datagram->data_size);
            cur_data += datagram->data_size;

            // EtherCAT datagram footer
            EC_WRITE_U16(cur_data, 0x0000); // reset working counter
            cur_data += EC_DATAGRAM_FOOTER_SIZE;
        }

        if (list_empty(&sent_datagrams)) {
            if (unlikely(master->debug_level > 1))
                EC_DBG("nothing to send.\n");
            break;
        }

        // EtherCAT frame header
        EC_WRITE_U16(frame_data, ((cur_data - frame_data
                                   - EC_FRAME_HEADER_SIZE) & 0x7FF) | 0x1000);

        // pad frame
        while (cur_data - frame_data < ETH_ZLEN - ETH_HLEN)
            EC_WRITE_U8(cur_data++, 0x00);

        if (unlikely(master->debug_level > 1))
            EC_DBG("frame size: %i\n", cur_data - frame_data);

        // send frame
        ec_device_send(&master->main_device, cur_data - frame_data);
        cycles_sent = get_cycles();
        jiffies_sent = jiffies;

        // set datagram states and sending timestamps
        list_for_each_entry_safe(datagram, next, &sent_datagrams, sent) {
            datagram->state = EC_DATAGRAM_SENT;
            datagram->cycles_sent = cycles_sent;
            datagram->jiffies_sent = jiffies_sent;
            list_del_init(&datagram->sent); // empty list of sent datagrams
        }

        frame_count++;
    }
    while (more_datagrams_waiting);

    if (unlikely(master->debug_level > 1)) {
        cycles_end = get_cycles();
        EC_DBG("ec_master_send_datagrams sent %i frames in %ius.\n",
               frame_count,
               (unsigned int) (cycles_end - cycles_start) * 1000 / cpu_khz);
    }
}

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

/**
   Processes a received frame.
   This function is called by the network driver for every received frame.
   \return 0 in case of success, else < 0
*/

void ec_master_receive_datagrams(ec_master_t *master, /**< EtherCAT master */
                                 const uint8_t *frame_data, /**< frame data */
                                 size_t size /**< size of the received data */
                                 )
{
    size_t frame_size, data_size;
    uint8_t datagram_type, datagram_index;
    unsigned int cmd_follows, matched;
    const uint8_t *cur_data;
    ec_datagram_t *datagram;

    if (unlikely(size < EC_FRAME_HEADER_SIZE)) {
        master->stats.corrupted++;
        ec_master_output_stats(master);
        return;
    }

    cur_data = frame_data;

    // check length of entire frame
    frame_size = EC_READ_U16(cur_data) & 0x07FF;
    cur_data += EC_FRAME_HEADER_SIZE;

    if (unlikely(frame_size > size)) {
        master->stats.corrupted++;
        ec_master_output_stats(master);
        return;
    }

    cmd_follows = 1;
    while (cmd_follows) {
        // process datagram header
        datagram_type  = EC_READ_U8 (cur_data);
        datagram_index = EC_READ_U8 (cur_data + 1);
        data_size      = EC_READ_U16(cur_data + 6) & 0x07FF;
        cmd_follows    = EC_READ_U16(cur_data + 6) & 0x8000;
        cur_data += EC_DATAGRAM_HEADER_SIZE;

        if (unlikely(cur_data - frame_data
                     + data_size + EC_DATAGRAM_FOOTER_SIZE > size)) {
            master->stats.corrupted++;
            ec_master_output_stats(master);
            return;
        }

        // search for matching datagram in the queue
        matched = 0;
        list_for_each_entry(datagram, &master->datagram_queue, queue) {
            if (datagram->index == datagram_index
                && datagram->state == EC_DATAGRAM_SENT
                && datagram->type == datagram_type
                && datagram->data_size == data_size) {
                matched = 1;
                break;
            }
        }

        // no matching datagram was found
        if (!matched) {
            master->stats.unmatched++;
            ec_master_output_stats(master);

            if (unlikely(master->debug_level > 0)) {
                EC_DBG("UNMATCHED datagram:\n");
                ec_print_data(cur_data - EC_DATAGRAM_HEADER_SIZE,
                        EC_DATAGRAM_HEADER_SIZE + data_size
                        + EC_DATAGRAM_FOOTER_SIZE);
#ifdef EC_DEBUG_RING
                ec_device_debug_ring_print(&master->main_device);
#endif
            }

            cur_data += data_size + EC_DATAGRAM_FOOTER_SIZE;
            continue;
        }

        // copy received data into the datagram memory
        memcpy(datagram->data, cur_data, data_size);
        cur_data += data_size;

        // set the datagram's working counter
        datagram->working_counter = EC_READ_U16(cur_data);
        cur_data += EC_DATAGRAM_FOOTER_SIZE;

        // dequeue the received datagram
        datagram->state = EC_DATAGRAM_RECEIVED;
        datagram->cycles_received = master->main_device.cycles_poll;
        datagram->jiffies_received = master->main_device.jiffies_poll;
        list_del_init(&datagram->queue);
    }
}

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

/**
   Output statistics in cyclic mode.
   This function outputs statistical data on demand, but not more often than
   necessary. The output happens at most once a second.
*/

void ec_master_output_stats(ec_master_t *master /**< EtherCAT master */)
{
    if (unlikely(jiffies - master->stats.output_jiffies >= HZ)) {
        master->stats.output_jiffies = jiffies;

        if (master->stats.timeouts) {
            EC_WARN("%i datagram%s TIMED OUT!\n", master->stats.timeouts,
                    master->stats.timeouts == 1 ? "" : "s");
            master->stats.timeouts = 0;
        }
        if (master->stats.corrupted) {
            EC_WARN("%i frame%s CORRUPTED!\n", master->stats.corrupted,
                    master->stats.corrupted == 1 ? "" : "s");
            master->stats.corrupted = 0;
        }
        if (master->stats.unmatched) {
            EC_WARN("%i datagram%s UNMATCHED!\n", master->stats.unmatched,
                    master->stats.unmatched == 1 ? "" : "s");
            master->stats.unmatched = 0;
        }
    }
}

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

/**
 * Master kernel thread function for IDLE mode.
 */

static int ec_master_idle_thread(ec_master_t *master)
{
    cycles_t cycles_start, cycles_end;

    daemonize("EtherCAT-IDLE");
    allow_signal(SIGTERM);

    while (!signal_pending(current)) {
        cycles_start = get_cycles();
        ec_datagram_output_stats(&master->fsm_datagram);

        if (ec_fsm_master_running(&master->fsm)) { // datagram on the way
            // receive
            spin_lock_bh(&master->internal_lock);
            ecrt_master_receive(master);
            spin_unlock_bh(&master->internal_lock);

            if (master->fsm_datagram.state == EC_DATAGRAM_SENT)
                goto schedule;
        }

        // execute master state machine
        if (ec_fsm_master_exec(&master->fsm)) { // datagram ready for sending
            // queue and send
            spin_lock_bh(&master->internal_lock);
            ec_master_queue_datagram(master, &master->fsm_datagram);
            ecrt_master_send(master);
            spin_unlock_bh(&master->internal_lock);
        }
        
        cycles_end = get_cycles();
        master->idle_cycle_times[master->idle_cycle_time_pos]
            = (u32) (cycles_end - cycles_start) * 1000 / cpu_khz;
        master->idle_cycle_time_pos++;
        master->idle_cycle_time_pos %= HZ;

schedule:
        if (ec_fsm_master_idle(&master->fsm)) {
            set_current_state(TASK_INTERRUPTIBLE);
            schedule_timeout(1);
        }
        else {
            schedule();
        }
    }
    
    master->thread_id = 0;
    if (master->debug_level)
        EC_DBG("Master IDLE thread exiting...\n");
    complete_and_exit(&master->thread_exit, 0);
}

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

/**
 * Master kernel thread function for IDLE mode.
 */

static int ec_master_operation_thread(ec_master_t *master)
{
    cycles_t cycles_start, cycles_end;

    daemonize("EtherCAT-OP");
    allow_signal(SIGTERM);

    while (!signal_pending(current)) {
        ec_datagram_output_stats(&master->fsm_datagram);
        if (master->injection_seq_rt != master->injection_seq_fsm ||
                master->fsm_datagram.state == EC_DATAGRAM_SENT ||
                master->fsm_datagram.state == EC_DATAGRAM_QUEUED)
            goto schedule;

        cycles_start = get_cycles();

        // output statistics
        ec_master_output_stats(master);

        // execute master state machine
        if (ec_fsm_master_exec(&master->fsm)) {
            // inject datagram
            master->injection_seq_fsm++;
        }

        cycles_end = get_cycles();
        master->idle_cycle_times[master->idle_cycle_time_pos]
            = (u32) (cycles_end - cycles_start) * 1000 / cpu_khz;
        master->idle_cycle_time_pos++;
        master->idle_cycle_time_pos %= HZ;

schedule:
        if (ec_fsm_master_idle(&master->fsm)) {
            set_current_state(TASK_INTERRUPTIBLE);
            schedule_timeout(1);
        }
        else {
            schedule();
        }
    }
    
    master->thread_id = 0;
    if (master->debug_level)
        EC_DBG("Master OP thread exiting...\n");
    complete_and_exit(&master->thread_exit, 0);
}

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

/**
 * Prints the device information to a buffer.
 * \return number of bytes written.
 */

ssize_t ec_master_device_info(
        const ec_device_t *device, /**< EtherCAT device */
        const uint8_t *mac, /**< MAC address */
        char *buffer /**< target buffer */
        )
{
    unsigned int frames_lost;
    off_t off = 0;
    
    if (ec_mac_is_zero(mac)) {
        off += sprintf(buffer + off, "none.\n");
    }
    else {
        off += ec_mac_print(mac, buffer + off);
    
        if (device->dev) {
            off += sprintf(buffer + off, " (connected).\n");      
            off += sprintf(buffer + off, "    Frames sent:     %u\n",
                    device->tx_count);
            off += sprintf(buffer + off, "    Frames received: %u\n",
                    device->rx_count);
            frames_lost = device->tx_count - device->rx_count;
            if (frames_lost) frames_lost--;
            off += sprintf(buffer + off, "    Frames lost:     %u\n", frames_lost);
        }
        else {
            off += sprintf(buffer + off, " (WAITING).\n");      
        }
    }
    
    return off;
}

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

/**
   Formats master information for SysFS read access.
   \return number of bytes written
*/

ssize_t ec_master_info(ec_master_t *master, /**< EtherCAT master */
                       char *buffer /**< memory to store data */
                       )
{
    off_t off = 0;
#ifdef EC_EOE
    ec_eoe_t *eoe;
#endif
    uint32_t cur, sum, min, max, pos, i;

    off += sprintf(buffer + off, "\nMode: ");
    switch (master->mode) {
        case EC_MASTER_MODE_ORPHANED:
            off += sprintf(buffer + off, "ORPHANED");
            break;
        case EC_MASTER_MODE_IDLE:
            off += sprintf(buffer + off, "IDLE");
            break;
        case EC_MASTER_MODE_OPERATION:
            off += sprintf(buffer + off, "OPERATION");
            break;
    }

    off += sprintf(buffer + off, "\nSlaves: %i\n",
                   master->slave_count);
    off += sprintf(buffer + off, "Status: %s\n",
                   master->fsm.tainted ? "TAINTED" : "sane");
    off += sprintf(buffer + off, "Pdo slaves: %s\n",
                   master->pdo_slaves_offline ? "INCOMPLETE" : "online");

    off += sprintf(buffer + off, "\nDevices:\n");
    
    down(&master->device_sem);
    off += sprintf(buffer + off, "  Main: ");
    off += ec_master_device_info(&master->main_device,
            master->main_mac, buffer + off);
    off += sprintf(buffer + off, "  Backup: ");
    off += ec_master_device_info(&master->backup_device,
            master->backup_mac, buffer + off);
    up(&master->device_sem);

    off += sprintf(buffer + off, "\nTiming (min/avg/max) [us]:\n");

    sum = 0;
    min = 0xFFFFFFFF;
    max = 0;
    pos = master->idle_cycle_time_pos;
    for (i = 0; i < HZ; i++) {
        cur = master->idle_cycle_times[(i + pos) % HZ];
        sum += cur;
        if (cur < min) min = cur;
        if (cur > max) max = cur;
    }
    off += sprintf(buffer + off, "  Idle cycle: %u / %u.%u / %u\n",
                   min, sum / HZ, (sum * 100 / HZ) % 100, max);

#ifdef EC_EOE
    sum = 0;
    min = 0xFFFFFFFF;
    max = 0;
    pos = master->eoe_cycle_time_pos;
    for (i = 0; i < HZ; i++) {
        cur = master->eoe_cycle_times[(i + pos) % HZ];
        sum += cur;
        if (cur < min) min = cur;
        if (cur > max) max = cur;
    }
    off += sprintf(buffer + off, "  EoE cycle: %u / %u.%u / %u\n",
                   min, sum / HZ, (sum * 100 / HZ) % 100, max);

    if (!list_empty(&master->eoe_handlers))
        off += sprintf(buffer + off, "\nEoE statistics (RX/TX) [bps]:\n");
    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        off += sprintf(buffer + off, "  %s: %u / %u (%u KB/s)\n",
                       eoe->dev->name, eoe->rx_rate, eoe->tx_rate,
                       ((eoe->rx_rate + eoe->tx_rate) / 8 + 512) / 1024);
    }
#endif

    off += sprintf(buffer + off, "\n");

    return off;
}

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

/**
   Formats attribute data for SysFS read access.
   \return number of bytes to read
*/

ssize_t ec_show_master_attribute(struct kobject *kobj, /**< kobject */
                                 struct attribute *attr, /**< attribute */
                                 char *buffer /**< memory to store data */
                                 )
{
    ec_master_t *master = container_of(kobj, ec_master_t, kobj);

    if (attr == &attr_info) {
        return ec_master_info(master, buffer);
    }
    else if (attr == &attr_debug_level) {
        return sprintf(buffer, "%i\n", master->debug_level);
    }

    return 0;
}

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

/**
   Formats attribute data for SysFS write access.
   \return number of bytes processed, or negative error code
*/

ssize_t ec_store_master_attribute(struct kobject *kobj, /**< slave's kobject */
                                  struct attribute *attr, /**< attribute */
                                  const char *buffer, /**< memory with data */
                                  size_t size /**< size of data to store */
                                  )
{
    ec_master_t *master = container_of(kobj, ec_master_t, kobj);

    if (attr == &attr_debug_level) {
        if (!strcmp(buffer, "0\n")) {
            master->debug_level = 0;
        }
        else if (!strcmp(buffer, "1\n")) {
            master->debug_level = 1;
        }
        else if (!strcmp(buffer, "2\n")) {
            master->debug_level = 2;
        }
        else {
            EC_ERR("Invalid debug level value!\n");
            return -EINVAL;
        }

        EC_INFO("Master debug level set to %i.\n", master->debug_level);
        return size;
    }

    return -EINVAL;
}

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

#ifdef EC_EOE
/**
   Starts Ethernet-over-EtherCAT processing on demand.
*/

void ec_master_eoe_start(ec_master_t *master /**< EtherCAT master */)
{
    if (master->eoe_running) {
        EC_WARN("EoE already running!\n");
        return;
    }

    if (list_empty(&master->eoe_handlers))
        return;

    if (!master->request_cb || !master->release_cb) {
        EC_WARN("No EoE processing because of missing locking callbacks!\n");
        return;
    }

    EC_INFO("Starting EoE processing.\n");
    master->eoe_running = 1;

    // start EoE processing
    master->eoe_timer.expires = jiffies + 10;
    add_timer(&master->eoe_timer);
}

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

/**
   Stops the Ethernet-over-EtherCAT processing.
*/

void ec_master_eoe_stop(ec_master_t *master /**< EtherCAT master */)
{
    if (!master->eoe_running) return;

    EC_INFO("Stopping EoE processing.\n");

    del_timer_sync(&master->eoe_timer);
    master->eoe_running = 0;
}

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

/**
   Does the Ethernet-over-EtherCAT processing.
*/

void ec_master_eoe_run(unsigned long data /**< master pointer */)
{
    ec_master_t *master = (ec_master_t *) data;
    ec_eoe_t *eoe;
    unsigned int none_open = 1;
    cycles_t cycles_start, cycles_end;
    unsigned long restart_jiffies;

    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        if (ec_eoe_is_open(eoe)) {
            none_open = 0;
            break;
        }
    }
    if (none_open)
        goto queue_timer;

    // receive datagrams
    if (master->request_cb(master->cb_data)) goto queue_timer;
    cycles_start = get_cycles();
    ecrt_master_receive(master);
    master->release_cb(master->cb_data);

    // actual EoE processing
    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        ec_eoe_run(eoe);
    }

    // send datagrams
    if (master->request_cb(master->cb_data)) {
        goto queue_timer;
    }
    list_for_each_entry(eoe, &master->eoe_handlers, list) {
        ec_eoe_queue(eoe);
    }
    ecrt_master_send(master);
    master->release_cb(master->cb_data);
    cycles_end = get_cycles();

    master->eoe_cycle_times[master->eoe_cycle_time_pos]
        = (u32) (cycles_end - cycles_start) * 1000 / cpu_khz;
    master->eoe_cycle_time_pos++;
    master->eoe_cycle_time_pos %= HZ;

 queue_timer:
    restart_jiffies = HZ / EC_EOE_FREQUENCY;
    if (!restart_jiffies) restart_jiffies = 1;
    master->eoe_timer.expires = jiffies + restart_jiffies;
    add_timer(&master->eoe_timer);
}
#endif

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

/**
   Prepares synchronous IO.
   Queues all domain datagrams and sends them. Then waits a certain time, so
   that ecrt_master_receive() can be called securely.
*/

void ec_master_prepare(ec_master_t *master /**< EtherCAT master */)
{
    ec_domain_t *domain;
    cycles_t cycles_start, cycles_end, cycles_timeout;

    // queue datagrams of all domains
    list_for_each_entry(domain, &master->domains, list)
        ecrt_domain_queue(domain);

    ecrt_master_send(master);

    cycles_start = get_cycles();
    cycles_timeout = (cycles_t) EC_IO_TIMEOUT /* us */ * (cpu_khz / 1000);

    // active waiting
    while (1) {
        udelay(100);
        cycles_end = get_cycles();
        if (cycles_end - cycles_start >= cycles_timeout) break;
    }
}

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

/** Detaches the slave configurations from the slaves.
 */
void ec_master_detach_slave_configs(
        ec_master_t *master /**< EtherCAT master. */
        )
{
    ec_slave_config_t *sc;

    if (!master->configs_attached)
        return;

    list_for_each_entry(sc, &master->configs, list) {
        ec_slave_config_detach(sc); 
    }

    master->configs_attached = 0;
}

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

/** Attaches the slave configurations to the slaves.
 */
int ec_master_attach_slave_configs(
        ec_master_t *master /**< EtherCAT master. */
        )
{
    ec_slave_config_t *sc;
    unsigned int errors = 0;

    if (master->configs_attached)
        return 0;

    list_for_each_entry(sc, &master->configs, list) {
        if (ec_slave_config_attach(sc))
            errors = 1;
    }

    master->configs_attached = !errors;
    return errors ? -1 : 0;
}

/******************************************************************************
 *  Realtime interface
 *****************************************************************************/

ec_domain_t *ecrt_master_create_domain(ec_master_t *master /**< master */)
{
    ec_domain_t *domain, *last_domain;
    unsigned int index;

    if (!(domain = (ec_domain_t *) kmalloc(sizeof(ec_domain_t), GFP_KERNEL))) {
        EC_ERR("Error allocating domain memory!\n");
        return NULL;
    }

    if (list_empty(&master->domains)) index = 0;
    else {
        last_domain = list_entry(master->domains.prev, ec_domain_t, list);
        index = last_domain->index + 1;
    }

    if (ec_domain_init(domain, master, index)) {
        EC_ERR("Failed to init domain.\n");
        return NULL;
    }

    list_add_tail(&domain->list, &master->domains);

    return domain;
}

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

int ecrt_master_activate(ec_master_t *master)
{
    uint32_t domain_offset;
    ec_domain_t *domain;

    // finish all domains
    domain_offset = 0;
    list_for_each_entry(domain, &master->domains, list) {
        if (ec_domain_finish(domain, domain_offset)) {
            EC_ERR("Failed to finish domain %X!\n", (u32) domain);
            return -1;
        }
        domain_offset += domain->data_size;
    }

    // request slave configuration
    down(&master->config_sem);
    master->allow_config = 1; // request the current configuration
    up(&master->config_sem);

    if (master->main_device.link_state) {
        // wait for configuration to complete
        master->config_state = EC_REQUEST_BUSY;
        if (wait_event_interruptible(master->config_queue,
                    master->config_state != EC_REQUEST_BUSY)) {
            EC_INFO("Waiting for configuration interrupted by signal.\n");
            return -1;
        }

        if (master->config_state != EC_REQUEST_SUCCESS) {
            EC_ERR("Failed to configure slaves.\n");
            return -1;
        }
    }
    
    // restart EoE process and master thread with new locking
#ifdef EC_EOE
    ec_master_eoe_stop(master);
#endif
    ec_master_thread_stop(master);

    ec_master_prepare(master); // prepare asynchronous IO

    if (master->debug_level)
        EC_DBG("FSM datagram is %x.\n", (unsigned int) &master->fsm_datagram);

    master->injection_seq_fsm = 0;
    master->injection_seq_rt = 0;
    master->request_cb = master->ext_request_cb;
    master->release_cb = master->ext_release_cb;
    master->cb_data = master->ext_cb_data;
    
    if (ec_master_thread_start(master, ec_master_operation_thread)) {
        EC_ERR("Failed to start master thread!\n");
        return -1;
    }
#ifdef EC_EOE
    ec_master_eoe_start(master);
#endif
    return 0;
}

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

void ecrt_master_send(ec_master_t *master)
{
    ec_datagram_t *datagram, *n;

    if (master->injection_seq_rt != master->injection_seq_fsm) {
        // inject datagram produced by master FSM
        ec_master_queue_datagram(master, &master->fsm_datagram);
        master->injection_seq_rt = master->injection_seq_fsm;
    }

    if (unlikely(!master->main_device.link_state)) {
        // link is down, no datagram can be sent
        list_for_each_entry_safe(datagram, n, &master->datagram_queue, queue) {
            datagram->state = EC_DATAGRAM_ERROR;
            list_del_init(&datagram->queue);
        }

        // query link state
        ec_device_poll(&master->main_device);
        return;
    }

    // send frames
    ec_master_send_datagrams(master);
}

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

void ecrt_master_receive(ec_master_t *master)
{
    ec_datagram_t *datagram, *next;
    cycles_t cycles_timeout;
    unsigned int frames_timed_out = 0;

    // receive datagrams
    ec_device_poll(&master->main_device);

    cycles_timeout = (cycles_t) EC_IO_TIMEOUT /* us */ * (cpu_khz / 1000);

    // dequeue all datagrams that timed out
    list_for_each_entry_safe(datagram, next, &master->datagram_queue, queue) {
        if (datagram->state != EC_DATAGRAM_SENT) continue;

        if (master->main_device.cycles_poll - datagram->cycles_sent
            > cycles_timeout) {
            frames_timed_out = 1;
            list_del_init(&datagram->queue);
            datagram->state = EC_DATAGRAM_TIMED_OUT;
            master->stats.timeouts++;
            ec_master_output_stats(master);

            if (unlikely(master->debug_level > 0)) {
                EC_DBG("TIMED OUT datagram %08x, index %02X waited %u us.\n",
                        (unsigned int) datagram, datagram->index,
                        (unsigned int) (master->main_device.cycles_poll
                            - datagram->cycles_sent) * 1000 / cpu_khz);
            }
        }
    }

    master->frames_timed_out = frames_timed_out;
}

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

ec_slave_config_t *ecrt_master_slave_config(ec_master_t *master,
        uint16_t alias, uint16_t position, uint32_t vendor_id,
        uint32_t product_code)
{
    ec_slave_config_t *sc;
    unsigned int found = 0;

    list_for_each_entry(sc, &master->configs, list) {
        if (sc->alias == alias && sc->position == position) {
            found = 1;
            break;
        }
    }

    if (found) {
        if (master->debug_level) {
            EC_INFO("Using existing slave configuration for %u:%u\n",
                    alias, position);
        }
        if (sc->vendor_id != vendor_id || sc->product_code != product_code) {
            EC_ERR("Slave type mismatch. Slave was configured as"
                    " 0x%08X/0x%08X before. Now configuring with"
                    " 0x%08X/0x%08X.\n", sc->vendor_id, sc->product_code,
                    vendor_id, product_code);
            return NULL;
        }
    } else {
        if (master->debug_level) {
            EC_INFO("Creating slave configuration for %u:%u,"
                    " 0x%08X/0x%08X.\n", alias, position, vendor_id,
                    product_code);
        }

        if (!(sc = (ec_slave_config_t *) kmalloc(sizeof(ec_slave_config_t),
                        GFP_KERNEL))) {
            EC_ERR("Failed to allocate memory for slave configuration.\n");
            return NULL;
        }

        if (ec_slave_config_init(sc, master, alias, position, vendor_id,
                    product_code)) {
            EC_ERR("Failed to init slave configuration.\n");
            return NULL;
        }

        // try to find the addressed slave
        ec_slave_config_attach(sc);
        ec_slave_config_load_default_mapping(sc);

        list_add_tail(&sc->list, &master->configs);
    }

    return sc;
}

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

void ecrt_master_callbacks(ec_master_t *master, int (*request_cb)(void *),
        void (*release_cb)(void *), void *cb_data)
{
    master->ext_request_cb = request_cb;
    master->ext_release_cb = release_cb;
    master->ext_cb_data = cb_data;
}

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

void ecrt_master_state(const ec_master_t *master, ec_master_state_t *state)
{
    state->bus_state =
        (master->pdo_slaves_offline || master->frames_timed_out)
        ? EC_BUS_FAILURE : EC_BUS_OK;
    state->bus_tainted = master->fsm.tainted; 
    state->slaves_responding = master->fsm.slaves_responding;
}

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

/** \cond */

EXPORT_SYMBOL(ecrt_master_create_domain);
EXPORT_SYMBOL(ecrt_master_activate);
EXPORT_SYMBOL(ecrt_master_send);
EXPORT_SYMBOL(ecrt_master_receive);
EXPORT_SYMBOL(ecrt_master_callbacks);
EXPORT_SYMBOL(ecrt_master_slave_config);
EXPORT_SYMBOL(ecrt_master_state);

/** \endcond */

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