/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2008  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.
 *
 *****************************************************************************/

#include <linux/version.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/err.h>

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
#include <linux/semaphore.h>
#else
#include <asm/semaphore.h>
#endif

#include "../../include/ecrt.h" // EtherCAT realtime interface

#include "serial.h"

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

// Module parameters
#define FREQUENCY 100

// Optional features

#define PFX "ec_tty_example: "

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

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

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

// Timer
static struct timer_list timer;

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

// process data
static uint8_t *domain1_pd; // process data memory

#define BusCouplerPos  0, 0

#define Beckhoff_EK1100 0x00000002, 0x044c2c52

static unsigned int counter = 0;

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

void check_domain1_state(void)
{
    ec_domain_state_t ds;

    down(&master_sem);
    ecrt_domain_state(domain1, &ds);
    up(&master_sem);

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

    domain1_state = ds;
}

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

void check_master_state(void)
{
    ec_master_state_t ms;

    down(&master_sem);
    ecrt_master_state(master, &ms);
    up(&master_sem);

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

    master_state = ms;
}

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

#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
void cyclic_task(struct timer_list *t)
#else
void cyclic_task(unsigned long data)
#endif
{
    // receive process data
    down(&master_sem);
    ecrt_master_receive(master);
    ecrt_domain_process(domain1);
    up(&master_sem);

    // 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();
    }

    run_serial_devices(domain1_pd);

    // send process data
    down(&master_sem);
    ecrt_domain_queue(domain1);
    ecrt_master_send(master);
    up(&master_sem);

    // restart timer
    timer.expires += HZ / FREQUENCY;
    add_timer(&timer);
}

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

void send_callback(void *cb_data)
{
    ec_master_t *m = (ec_master_t *) cb_data;
    down(&master_sem);
    ecrt_master_send_ext(m);
    up(&master_sem);
}

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

void receive_callback(void *cb_data)
{
    ec_master_t *m = (ec_master_t *) cb_data;
    down(&master_sem);
    ecrt_master_receive(m);
    up(&master_sem);
}

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

int __init init_mini_module(void)
{
    int ret = -1;
    ec_slave_config_t *sc;

    printk(KERN_INFO PFX "Starting...\n");

    master = ecrt_request_master(0);
    if (!master) {
        printk(KERN_ERR PFX "Requesting master 0 failed.\n");
        ret = -EBUSY;
        goto out_return;
    }

    sema_init(&master_sem, 1);
    ecrt_master_callbacks(master, send_callback, receive_callback, master);

    printk(KERN_INFO PFX "Registering domain...\n");
    if (!(domain1 = ecrt_master_create_domain(master))) {
        printk(KERN_ERR PFX "Domain creation failed!\n");
        goto out_release_master;
    }

    // Create configuration for bus coupler
    sc = ecrt_master_slave_config(master, BusCouplerPos, Beckhoff_EK1100);
    if (!sc) {
        printk(KERN_ERR PFX "Failed to create slave config.\n");
        ret = -ENOMEM;
        goto out_release_master;
    }

    create_serial_devices(master, domain1);

    printk(KERN_INFO PFX "Activating master...\n");
    if (ecrt_master_activate(master)) {
        printk(KERN_ERR PFX "Failed to activate master!\n");
        goto out_free_serial;
    }

    // Get internal process data for domain
    domain1_pd = ecrt_domain_data(domain1);

    printk(KERN_INFO PFX "Starting cyclic sample thread.\n");
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
    timer_setup(&timer, cyclic_task, 0);
#else
    init_timer(&timer);
    timer.function = cyclic_task;
#endif
    timer.expires = jiffies + 10;
    add_timer(&timer);

    printk(KERN_INFO PFX "Started.\n");
    return 0;

out_free_serial:
    free_serial_devices();
out_release_master:
    printk(KERN_ERR PFX "Releasing master...\n");
    ecrt_release_master(master);
out_return:
    printk(KERN_ERR PFX "Failed to load. Aborting.\n");
    return ret;
}

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

void __exit cleanup_mini_module(void)
{
    printk(KERN_INFO PFX "Stopping...\n");

    del_timer_sync(&timer);

    free_serial_devices();

    printk(KERN_INFO PFX "Releasing master...\n");
    ecrt_release_master(master);

    printk(KERN_INFO PFX "Unloading.\n");
}

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

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");
MODULE_DESCRIPTION("EtherCAT minimal test environment");

module_init(init_mini_module);
module_exit(cleanup_mini_module);

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