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

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 *

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 *  RTAI sample for the IgH EtherCAT master.

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 *

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 *  $Id$

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 *

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 *  Copyright (C) 2006  Florian Pose, Ingenieurgemeinschaft IgH

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 *

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 *  This file is part of the IgH EtherCAT Master.

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 *

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 *  The IgH EtherCAT Master is free software; you can redistribute it

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 *  and/or modify it under the terms of the GNU General Public License

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 *  as published by the Free Software Foundation; either version 2 of the

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 *  License, or (at your option) any later version.

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 *

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 *  The IgH EtherCAT Master is distributed in the hope that it will be

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 *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of

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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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 *  GNU General Public License for more details.

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 *

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 *  You should have received a copy of the GNU General Public License

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 *  along with the IgH EtherCAT Master; if not, write to the Free Software

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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

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 *

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 *  The right to use EtherCAT Technology is granted and comes free of

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 *  charge under condition of compatibility of product made by

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 *  Licensee. People intending to distribute/sell products based on the

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 *  code, have to sign an agreement to guarantee that products using

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 *  software based on IgH EtherCAT master stay compatible with the actual

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 *  EtherCAT specification (which are released themselves as an open

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 *  standard) as the (only) precondition to have the right to use EtherCAT

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 *  Technology, IP and trade marks.

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 *

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

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// Linux

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#include <linux/module.h>

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// RTAI

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#include "rtai_sched.h"

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#include "rtai_sem.h"

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// EtherCAT

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#include "../../include/ecrt.h"

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#include "../../include/ecdb.h"

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

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// RTAI task frequency in Hz

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#define FREQUENCY 4000

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#define INHIBIT_TIME 20

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#define TIMERTICKS (1000000000 / FREQUENCY)

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

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// RTAI

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RT_TASK task;

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SEM master_sem;

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cycles_t t_last_cycle = 0, t_critical;

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// EtherCAT

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ec_master_t *master = NULL;

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ec_domain_t *domain1 = NULL;

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// data fields

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void *r_dig_out;

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ec_pdo_reg_t domain1_pdos[] = {

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    {"2", Beckhoff_EL2004_Outputs, &r_dig_out},

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    {}

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};

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

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void run(long data)

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{

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    static unsigned int blink = 0;

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    static unsigned int counter = 0;

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    while (1) {

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        t_last_cycle = get_cycles();

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        rt_sem_wait(&master_sem);

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        ecrt_master_receive(master);

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        ecrt_domain_process(domain1);

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        rt_sem_signal(&master_sem);

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        // process data

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        EC_WRITE_U8(r_dig_out, blink ? 0x0F : 0x00);

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        rt_sem_wait(&master_sem);

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        ecrt_domain_queue(domain1);

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        ecrt_master_send(master);

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        rt_sem_signal(&master_sem);

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        if (counter) {

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            counter--;

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        }

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        else {

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            counter = FREQUENCY;

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            blink = !blink;

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        }

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        rt_task_wait_period();

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    }

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}

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

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int request_lock(void *data)

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{

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    // too close to the next real time cycle: deny access...

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    if (get_cycles() - t_last_cycle > t_critical) return -1;

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    // allow access

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    rt_sem_wait(&master_sem);

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    return 0;

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}

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

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void release_lock(void *data)

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{

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    rt_sem_signal(&master_sem);

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}

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

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int __init init_mod(void)

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{

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    RTIME tick_period, requested_ticks, now;

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    printk(KERN_INFO "=== Starting EtherCAT RTAI sample module... ===\n");

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    rt_sem_init(&master_sem, 1);

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    t_critical = cpu_khz * 1000 / FREQUENCY - cpu_khz * INHIBIT_TIME / 1000;

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    if (!(master = ecrt_request_master(0))) {

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        printk(KERN_ERR "Requesting master 0 failed!\n");

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        goto out_return;

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    }

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    ecrt_master_callbacks(master, request_lock, release_lock, NULL);

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    printk(KERN_INFO "Creating domain...\n");

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    if (!(domain1 = ecrt_master_create_domain(master))) {

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        printk(KERN_ERR "Domain creation failed!\n");

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        goto out_release_master;

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    }

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    printk(KERN_INFO "Registering PDOs...\n");

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    if (ecrt_domain_register_pdo_list(domain1, domain1_pdos)) {

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        printk(KERN_ERR "PDO registration failed!\n");

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        goto out_release_master;

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    }

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    printk(KERN_INFO "Activating master...\n");

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    if (ecrt_master_activate(master)) {

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        printk(KERN_ERR "Failed to activate master!\n");

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        goto out_release_master;

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    }

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    printk("Starting cyclic sample thread...\n");

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    requested_ticks = nano2count(TIMERTICKS);

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    tick_period = start_rt_timer(requested_ticks);

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    printk(KERN_INFO "RT timer started with %i/%i ticks.\n",

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           (int) tick_period, (int) requested_ticks);

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    if (rt_task_init(&task, run, 0, 2000, 0, 1, NULL)) {

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        printk(KERN_ERR "Failed to init RTAI task!\n");

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        goto out_stop_timer;

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    }

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    now = rt_get_time();

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    if (rt_task_make_periodic(&task, now + tick_period, tick_period)) {

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        printk(KERN_ERR "Failed to run RTAI task!\n");

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        goto out_stop_task;

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    }

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    printk(KERN_INFO "=== EtherCAT RTAI sample module started. ===\n");

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    return 0;

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 out_stop_task:

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    rt_task_delete(&task);

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 out_stop_timer:

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    stop_rt_timer();

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 out_release_master:

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    ecrt_release_master(master);

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 out_return:

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    rt_sem_delete(&master_sem);

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    return -1;

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}

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

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void __exit cleanup_mod(void)

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{

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    printk(KERN_INFO "=== Stopping EtherCAT RTAI sample module... ===\n");

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    rt_task_delete(&task);

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    stop_rt_timer();

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    ecrt_release_master(master);

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    rt_sem_delete(&master_sem);

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    printk(KERN_INFO "=== EtherCAT RTAI sample module stopped. ===\n");

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}

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

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MODULE_LICENSE("GPL");

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MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");

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MODULE_DESCRIPTION("EtherCAT RTAI sample module");

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module_init(init_mod);

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module_exit(cleanup_mod);

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