/*****************************************************************************
 *
 *  Copyright (C) 2007-2026  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
 *
 ****************************************************************************/

#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <sys/mman.h>
#include <malloc.h>
#include <sched.h> /* sched_setscheduler() */

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

#include "ecrt.h"

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

// Application parameters
#define FREQUENCY 1000
#define CLOCK_TO_USE CLOCK_MONOTONIC
#define MEASURE_TIMING

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

#define NSEC_PER_SEC (1000000000L)
#define PERIOD_NS (NSEC_PER_SEC / FREQUENCY)

#define DIFF_NS(A, B) (((B).tv_sec - (A).tv_sec) * NSEC_PER_SEC + \
        (B).tv_nsec - (A).tv_nsec)

#define TIMESPEC2NS(T) ((uint64_t) (T).tv_sec * NSEC_PER_SEC + (T).tv_nsec)

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

// EtherCAT
static ec_master_t *master = NULL;
static ec_master_state_t master_state = {};

static ec_domain_t *domain1 = NULL;
static ec_domain_state_t domain1_state = {};

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

// process data
static uint8_t *domain1_pd = NULL;

#define BusCouplerPos    0, 0
#define DigOutSlavePos   0, 1
#define CounterSlavePos  0, 2

#define Beckhoff_EK1100 0x00000002, 0x044c2c52
#define Beckhoff_EL2008 0x00000002, 0x07d83052
#define IDS_Counter     0x000012ad, 0x05de3052

// offsets for PDO entries
static int off_dig_out;
static int off_counter_in;
static int off_counter_out;

static unsigned int counter = 0;
static unsigned int blink = 0;
static unsigned int sync_ref_counter = 0;
const struct timespec cycletime = {0, PERIOD_NS};

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

struct timespec timespec_add(struct timespec time1, struct timespec time2)
{
    struct timespec result;

    if ((time1.tv_nsec + time2.tv_nsec) >= NSEC_PER_SEC) {
        result.tv_sec = time1.tv_sec + time2.tv_sec + 1;
        result.tv_nsec = time1.tv_nsec + time2.tv_nsec - NSEC_PER_SEC;
    } else {
        result.tv_sec = time1.tv_sec + time2.tv_sec;
        result.tv_nsec = time1.tv_nsec + time2.tv_nsec;
    }

    return result;
}

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

void check_domain1_state(void)
{
    ec_domain_state_t ds;

    ecrt_domain_state(domain1, &ds);

    if (ds.working_counter != domain1_state.working_counter)
        printf("Domain1: WC %u.\n", ds.working_counter);
    if (ds.wc_state != domain1_state.wc_state)
        printf("Domain1: State %u.\n", ds.wc_state);

    domain1_state = ds;
}

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

void check_master_state(void)
{
    ec_master_state_t ms;

    ecrt_master_state(master, &ms);

    if (ms.slaves_responding != master_state.slaves_responding)
        printf("%u slave(s).\n", ms.slaves_responding);
    if (ms.al_states != master_state.al_states)
        printf("AL states: 0x%02X.\n", ms.al_states);
    if (ms.link_up != master_state.link_up)
        printf("Link is %s.\n", ms.link_up ? "up" : "down");

    master_state = ms;
}

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

void cyclic_task()
{
    struct timespec wakeupTime, time;
#ifdef MEASURE_TIMING
    struct timespec startTime, endTime, lastStartTime = {};
    uint32_t period_ns = 0, exec_ns = 0, latency_ns = 0,
             latency_min_ns = 0, latency_max_ns = 0,
             period_min_ns = 0, period_max_ns = 0,
             exec_min_ns = 0, exec_max_ns = 0;
#endif

    // get current time
    clock_gettime(CLOCK_TO_USE, &wakeupTime);

    while(1) {
        wakeupTime = timespec_add(wakeupTime, cycletime);
        clock_nanosleep(CLOCK_TO_USE, TIMER_ABSTIME, &wakeupTime, NULL);

        // Write application time to master
        //
        // It is a good idea to use the target time (not the measured time) as
        // application time, because it is more stable.
        //
        ecrt_master_application_time(master, TIMESPEC2NS(wakeupTime));

#ifdef MEASURE_TIMING
        clock_gettime(CLOCK_TO_USE, &startTime);
        latency_ns = DIFF_NS(wakeupTime, startTime);
        period_ns = DIFF_NS(lastStartTime, startTime);
        exec_ns = DIFF_NS(lastStartTime, endTime);
        lastStartTime = startTime;

        if (latency_ns > latency_max_ns) {
            latency_max_ns = latency_ns;
        }
        if (latency_ns < latency_min_ns) {
            latency_min_ns = latency_ns;
        }
        if (period_ns > period_max_ns) {
            period_max_ns = period_ns;
        }
        if (period_ns < period_min_ns) {
            period_min_ns = period_ns;
        }
        if (exec_ns > exec_max_ns) {
            exec_max_ns = exec_ns;
        }
        if (exec_ns < exec_min_ns) {
            exec_min_ns = exec_ns;
        }
#endif

        // receive process data
        ecrt_master_receive(master);
        ecrt_domain_process(domain1);

        // check process data state (optional)
        check_domain1_state();

        if (counter) {
            counter--;
        } else { // do this at 1 Hz
            counter = FREQUENCY;

            // check for master state (optional)
            check_master_state();

#ifdef MEASURE_TIMING
            // output timing stats
            printf("period     %10u ... %10u\n",
                    period_min_ns, period_max_ns);
            printf("exec       %10u ... %10u\n",
                    exec_min_ns, exec_max_ns);
            printf("latency    %10u ... %10u\n",
                    latency_min_ns, latency_max_ns);
            period_max_ns = 0;
            period_min_ns = 0xffffffff;
            exec_max_ns = 0;
            exec_min_ns = 0xffffffff;
            latency_max_ns = 0;
            latency_min_ns = 0xffffffff;
#endif

            // calculate new process data
            blink = !blink;
        }

        // write process data
        EC_WRITE_U8(domain1_pd + off_dig_out, blink ? 0x66 : 0x99);
        EC_WRITE_U8(domain1_pd + off_counter_out, blink ? 0x00 : 0x02);

        if (sync_ref_counter) {
            sync_ref_counter--;
        } else {
            sync_ref_counter = 1; // sync every cycle

            clock_gettime(CLOCK_TO_USE, &time);
            ecrt_master_sync_reference_clock_to(master, TIMESPEC2NS(time));
        }
        ecrt_master_sync_slave_clocks(master);

        // send process data
        ecrt_domain_queue(domain1);
        ecrt_master_send(master);

#ifdef MEASURE_TIMING
        clock_gettime(CLOCK_TO_USE, &endTime);
#endif
    }
}

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

int main(int argc, char **argv)
{
    ec_slave_config_t *sc;

    if (mlockall(MCL_CURRENT | MCL_FUTURE) == -1) {
        perror("mlockall failed");
        return -1;
    }

    master = ecrt_request_master(0);
    if (!master)
        return -1;

    domain1 = ecrt_master_create_domain(master);
    if (!domain1)
        return -1;

    // Create configuration for bus coupler
    sc = ecrt_master_slave_config(master, BusCouplerPos, Beckhoff_EK1100);
    if (!sc)
        return -1;

    if (!(sc = ecrt_master_slave_config(master,
                    DigOutSlavePos, Beckhoff_EL2008))) {
        fprintf(stderr, "Failed to get slave configuration.\n");
        return -1;
    }

    off_dig_out = ecrt_slave_config_reg_pdo_entry(sc,
            0x7000, 1, domain1, NULL);
    if (off_dig_out < 0)
        return -1;

    if (!(sc = ecrt_master_slave_config(master,
                    CounterSlavePos, IDS_Counter))) {
        fprintf(stderr, "Failed to get slave configuration.\n");
        return -1;
    }

    off_counter_in = ecrt_slave_config_reg_pdo_entry(sc,
            0x6020, 0x11, domain1, NULL);
    if (off_counter_in < 0)
        return -1;

    off_counter_out = ecrt_slave_config_reg_pdo_entry(sc,
            0x7020, 1, domain1, NULL);
    if (off_counter_out < 0)
        return -1;

    // configure SYNC0/SYNC1 interrupts for this slave
    ecrt_slave_config_dc(sc,
            0x0700, // AssignActivate (see vendor docs)
            PERIOD_NS, // SYNC0 cycle time [ns]
            4400000, // SYNC0 shift time [ns]
            0, // SYNC1 cycle time [ns]
            0 // SYNC1 shift time [ns]
            );

    printf("Activating master...\n");
    if (ecrt_master_activate(master))
        return -1;

    if (!(domain1_pd = ecrt_domain_data(domain1))) {
        return -1;
    }

    /* Set priority */

    struct sched_param param = {};
    param.sched_priority = sched_get_priority_max(SCHED_FIFO);

    printf("Using priority %i.\n", param.sched_priority);
    if (sched_setscheduler(0, SCHED_FIFO, &param) == -1) {
        perror("sched_setscheduler failed");
    }

    printf("Starting cyclic function.\n");
    cyclic_task();

    return 0;
}

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