[etherlab-users] clock_gettime issue

Tommaso Furiosi furiosi.tommaso at gmail.com
Mon May 9 13:06:28 CEST 2016


Good morning,

I’m trying to create a simple application equal to the “user” example provided with the EtherCAT master documentation (the code is attached at the end of this message), but in a kernel version. I’ve adopted the basic environment of the “mini”example but i cannot include the “/usr/include” directory (where lies the time.h header, useful for the clock_gettime function).
Could you give me any hints in order to solve this problem?

Thank you for your help.

Tommaso

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

#include <time.h>


#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 34)
#include <linux/slab.h>
#endif

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

#include "/usr/local/etherlab/src/ethercat-1.5.2/include/ecrt.h" // EtherCAT realtime interface

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

// Module parameters
#define FREQUENCY 1000      

// Optional features
#define EXTERNAL_MEMORY 1

#define CLOCK_TO_USE CLOCK_REALTIME     
#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)

#define PFX "ec_mini: "

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

// 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 DigOutSlavePos   0, 1
#define AnaOutSlavePos   0, 6

#define Beckhoff_EK1100 0x00000002, 0x044c2c52
#define Beckhoff_EL2004 0x00000002, 0x07d43052
#define Beckhoff_EL4002 0x00000002, 0x0fa23052


// offsets for PDO entries
static unsigned int off_ana_out;
static unsigned int off_dig_out;


/*const static ec_pdo_entry_reg_t domain1_regs[] = {
    {AnaOutSlavePos, Beckhoff_EL4002, 0x7000, 1, &off_ana_out},
    {DigOutSlavePos, Beckhoff_EL2004, 0x7000, 1, &off_dig_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};

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

// Analog out -------------------------

ec_pdo_entry_info_t el4002_pdo_entries[] = {
    {0x7000, 0x01, 16}, /* Analog output */
    {0x7010, 0x01, 16}, /* Analog output */
};

ec_pdo_info_t el4002_pdos[] = {
    {0x1600, 1, el4002_pdo_entries + 0}, /* RxPDO-Map OutputsCh.1 */
    {0x1601, 1, el4002_pdo_entries + 1}, /* RxPDO-Map OutputsCh.2 */
};

ec_sync_info_t el4002_syncs[] = {
    {2, EC_DIR_OUTPUT, 2, el4002_pdos + 0, EC_WD_DISABLE},
    {3, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
    {0xff}
};

// Digital out ------------------------

ec_pdo_entry_info_t el2004_channels[] = {
    {0x7000, 0x01, 1}, /* Output */
    {0x7010, 0x01, 1}, /* Output */
    {0x7020, 0x01, 1}, /* Output */
    {0x7030, 0x01, 1}, /* Output */
};

ec_pdo_info_t el2004_pdos[] = {
    {0x1600, 1, &el2004_channels[0]},
    {0x1601, 1, &el2004_channels[1]},
    {0x1602, 1, &el2004_channels[2]},
    {0x1603, 1, &el2004_channels[3]}
};

ec_sync_info_t el2004_syncs[] = {
    {0, EC_DIR_OUTPUT, 4, el2004_pdos + 0, EC_WD_ENABLE},
    {1, EC_DIR_INPUT},
    {0xff}
};

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

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;

    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;
}

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

void cyclic_task(unsigned long data)
{

    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;

    // get current time from the clock set in "CLOCK_TO_USE" and put it into wakeupTime

    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
    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 { 
        counter = FREQUENCY;

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

#ifdef MEASURE_TIMING
        // output timing stats
        printk(KERN_INFO PFX "period     %10u ... %10u\n", period_min_ns, period_max_ns);
        printk(KERN_INFO PFX "exec       %10u ... %10u\n", exec_min_ns, exec_max_ns);
        printk(KERN_INFO PFX "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 ? 0x06 : 0x09);		

    // write application time to master
    clock_gettime(CLOCK_TO_USE, &time);
    ecrt_master_application_time(master, TIMESPEC2NS(time));

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

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

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

    // restart timer
    timer.expires += HZ/FREQUENCY;        
    add_timer(&timer);          
#ifdef MEASURE_TIMING
    clock_gettime(CLOCK_TO_USE, &wakeupTime);
#endif
}

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

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;

#if EXTERNAL_MEMORY
    unsigned int size;
#endif

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

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

    //Create configuration for digital output

    if (!(sc = ecrt_master_slave_config(master, DigOutSlavePos, Beckhoff_EL2004))) {
        printk(KERN_ERR PFX "Failed to get slave configuration.\n");
        goto out_release_master;
    }

    off_dig_out = ecrt_slave_config_reg_pdo_entry(sc, 0x7000, 1, domain1, NULL);
    if (off_dig_out < 0)
        goto out_release_master;

    ecrt_slave_config_dc(sc, 0x0300, PERIOD_NS, 4400000, 0, 0);

    if (!(sc = ecrt_master_slave_config(master, AnaOutSlavePos, Beckhoff_EL4002))) {
        printk(KERN_ERR PFX "Failed to get slave configuration.\n");
        goto out_release_master;
    }

    off_ana_out = ecrt_slave_config_reg_pdo_entry(sc, 0x7000, 1, domain1, NULL);
    if (off_dig_out < 0)
        goto out_release_master;

    // configure SYNC signals for this slave
    ecrt_slave_config_dc(sc, 0x0700, PERIOD_NS, 4400000, 0, 0);

/*
    if (!(sc = ecrt_master_slave_config(master, AnaOutSlavePos, Beckhoff_EL4002))) {	
        printk(KERN_ERR PFX "Failed to get slave configuration.\n");
        goto out_release_master;
    }

    if (ecrt_slave_config_pdos(sc, EC_END, el4002_syncs)) {
        printk(KERN_ERR PFX "Failed to configure PDOs.\n");
        goto out_release_master;
    }

    ecrt_slave_config_dc(sc, 0x0700, PERIOD_NS, 4400000, 0, 0);

    if (!(sc = ecrt_master_slave_config(master, DigOutSlavePos, Beckhoff_EL2004))) {
        printk(KERN_ERR PFX "Failed to get slave configuration.\n");
        goto out_release_master;
    }

    if (ecrt_slave_config_pdos(sc, EC_END, el2004_syncs)) {
        printk(KERN_ERR PFX "Failed to configure PDOs.\n");
        goto out_release_master;
    }

    ecrt_slave_config_dc(sc, 0x0300, PERIOD_NS, 4400000, 0, 0);

    printk(KERN_INFO PFX "Registering PDO entries...\n");
    if (ecrt_domain_reg_pdo_entry_list(domain1, domain1_regs)) {
        printk(KERN_ERR PFX "PDO entry registration failed!\n");
        goto out_release_master;
    }

*/

#if EXTERNAL_MEMORY
    if ((size = ecrt_domain_size(domain1))) {		
        if (!(domain1_pd = (uint8_t *) kmalloc(size, GFP_KERNEL))) {
            printk(KERN_ERR PFX "Failed to allocate %u bytes of process data memory!\n", size);
            goto out_release_master;
        }
        ecrt_domain_external_memory(domain1, domain1_pd);	
    }
#endif

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

#if EXTERNAL_MEMORY
        goto out_free_process_data;
#else
        goto out_release_master;
#endif
    }

#if !EXTERNAL_MEMORY
    // Get internal process data for domain
    domain1_pd = ecrt_domain_data(domain1);
#endif

    printk(KERN_INFO PFX "Starting cyclic sample thread.\n");
    init_timer(&timer);         
    timer.function = cyclic_task;       
    timer.expires = jiffies + 10;       
    add_timer(&timer);          

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

#if EXTERNAL_MEMORY
out_free_process_data:
    kfree(domain1_pd);
#endif
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);

#if EXTERNAL_MEMORY
    kfree(domain1_pd);
#endif

    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 at igh-essen.com>");
MODULE_DESCRIPTION("EtherCAT minimal test environment");

module_init(init_mini_module);
module_exit(cleanup_mini_module);

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