Fixed possible NULL pointer dereference; thanks to Matthieu Bec.
/******************************************************************************
*
* Distributed clocks sample for the IgH EtherCAT master.
*
* $Id$
*
* 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.
*
*****************************************************************************/
// Linux
#include <linux/module.h>
#include <linux/err.h>
// RTAI
#include <rtai_sched.h>
#include <rtai_sem.h>
// EtherCAT
#include "../../include/ecrt.h"
/*****************************************************************************/
// Module parameters
#define FREQUENCY 1000 // task frequency in Hz
#define INHIBIT_TIME 20
#define TIMERTICKS (1000000000 / FREQUENCY)
#define NUM_DIG_OUT 1
#define PFX "ec_dc_rtai_sample: "
/*****************************************************************************/
// 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 = {};
// RTAI
static RT_TASK task;
static SEM master_sem;
static cycles_t t_last_cycle = 0, t_critical;
/*****************************************************************************/
// process data
static uint8_t *domain1_pd; // process data memory
#define DigOutSlavePos(X) 0, (1 + (X))
#define CounterSlavePos 0, 2
#define Beckhoff_EK1100 0x00000002, 0x044c2c52
#define Beckhoff_EL2008 0x00000002, 0x07d83052
#define IDS_Counter 0x000012ad, 0x05de3052
static int off_dig_out[NUM_DIG_OUT];
static int off_counter_in;
static int off_counter_out;
static unsigned int counter = 0;
static unsigned int blink_counter = 0;
static unsigned int blink = 0;
static u32 counter_value = 0U;
/*****************************************************************************/
static ec_pdo_entry_info_t el2008_channels[] = {
{0x7000, 1, 1},
{0x7010, 1, 1},
{0x7020, 1, 1},
{0x7030, 1, 1},
{0x7040, 1, 1},
{0x7050, 1, 1},
{0x7060, 1, 1},
{0x7070, 1, 1}
};
static ec_pdo_info_t el2008_pdos[] = {
{0x1600, 1, &el2008_channels[0]},
{0x1601, 1, &el2008_channels[1]},
{0x1602, 1, &el2008_channels[2]},
{0x1603, 1, &el2008_channels[3]},
{0x1604, 1, &el2008_channels[4]},
{0x1605, 1, &el2008_channels[5]},
{0x1606, 1, &el2008_channels[6]},
{0x1607, 1, &el2008_channels[7]}
};
static ec_sync_info_t el2008_syncs[] = {
{0, EC_DIR_OUTPUT, 8, el2008_pdos},
{1, EC_DIR_INPUT},
{0xff}
};
/*****************************************************************************/
void check_domain1_state(void)
{
ec_domain_state_t ds;
rt_sem_wait(&master_sem);
ecrt_domain_state(domain1, &ds);
rt_sem_signal(&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;
rt_sem_wait(&master_sem);
ecrt_master_state(master, &ms);
rt_sem_signal(&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 run(long data)
{
int i;
struct timeval tv;
unsigned int sync_ref_counter = 0;
count2timeval(nano2count(rt_get_real_time_ns()), &tv);
while (1) {
t_last_cycle = get_cycles();
// receive process data
rt_sem_wait(&master_sem);
ecrt_master_receive(master);
ecrt_domain_process(domain1);
rt_sem_signal(&master_sem);
// check process data state (optional)
check_domain1_state();
if (counter) {
counter--;
} else {
u32 c;
counter = FREQUENCY;
// check for master state (optional)
check_master_state();
c = EC_READ_U32(domain1_pd + off_counter_in);
if (counter_value != c) {
counter_value = c;
printk(KERN_INFO PFX "counter=%u\n", counter_value);
}
}
if (blink_counter) {
blink_counter--;
} else {
blink_counter = 9;
// calculate new process data
blink = !blink;
}
// write process data
for (i = 0; i < NUM_DIG_OUT; i++) {
EC_WRITE_U8(domain1_pd + off_dig_out[i], blink ? 0x66 : 0x99);
}
EC_WRITE_U8(domain1_pd + off_counter_out, blink ? 0x00 : 0x02);
rt_sem_wait(&master_sem);
tv.tv_usec += 1000;
if (tv.tv_usec >= 1000000) {
tv.tv_usec -= 1000000;
tv.tv_sec++;
}
ecrt_master_application_time(master, EC_TIMEVAL2NANO(tv));
if (sync_ref_counter) {
sync_ref_counter--;
} else {
sync_ref_counter = 9;
ecrt_master_sync_reference_clock(master);
}
ecrt_master_sync_slave_clocks(master);
ecrt_domain_queue(domain1);
ecrt_master_send(master);
rt_sem_signal(&master_sem);
rt_task_wait_period();
}
}
/*****************************************************************************/
void send_callback(void *cb_data)
{
ec_master_t *m = (ec_master_t *) cb_data;
// too close to the next real time cycle: deny access...
if (get_cycles() - t_last_cycle <= t_critical) {
rt_sem_wait(&master_sem);
ecrt_master_send_ext(m);
rt_sem_signal(&master_sem);
}
}
/*****************************************************************************/
void receive_callback(void *cb_data)
{
ec_master_t *m = (ec_master_t *) cb_data;
// too close to the next real time cycle: deny access...
if (get_cycles() - t_last_cycle <= t_critical) {
rt_sem_wait(&master_sem);
ecrt_master_receive(m);
rt_sem_signal(&master_sem);
}
}
/*****************************************************************************/
int __init init_mod(void)
{
int ret = -1, i;
RTIME tick_period, requested_ticks, now;
ec_slave_config_t *sc;
printk(KERN_INFO PFX "Starting...\n");
rt_sem_init(&master_sem, 1);
t_critical = cpu_khz * 1000 / FREQUENCY - cpu_khz * INHIBIT_TIME / 1000;
master = ecrt_request_master(0);
if (!master) {
ret = -EBUSY;
printk(KERN_ERR PFX "Requesting master 0 failed!\n");
goto out_return;
}
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;
}
printk(KERN_INFO PFX "Configuring PDOs...\n");
// create configuration for reference clock FIXME
if (!(sc = ecrt_master_slave_config(master, 0, 0, Beckhoff_EK1100))) {
printk(KERN_ERR PFX "Failed to get slave configuration.\n");
goto out_release_master;
}
for (i = 0; i < NUM_DIG_OUT; i++) {
if (!(sc = ecrt_master_slave_config(master,
DigOutSlavePos(i), Beckhoff_EL2008))) {
printk(KERN_ERR PFX "Failed to get slave configuration.\n");
goto out_release_master;
}
if (ecrt_slave_config_pdos(sc, EC_END, el2008_syncs)) {
printk(KERN_ERR PFX "Failed to configure PDOs.\n");
goto out_release_master;
}
off_dig_out[i] = ecrt_slave_config_reg_pdo_entry(sc,
0x7000, 1, domain1, NULL);
if (off_dig_out[i] < 0)
goto out_release_master;
}
if (!(sc = ecrt_master_slave_config(master,
CounterSlavePos, IDS_Counter))) {
printk(KERN_ERR PFX "Failed to get slave configuration.\n");
goto out_release_master;
}
off_counter_in = ecrt_slave_config_reg_pdo_entry(sc,
0x6020, 0x11, domain1, NULL);
if (off_counter_in < 0)
goto out_release_master;
off_counter_out = ecrt_slave_config_reg_pdo_entry(sc,
0x7020, 1, domain1, NULL);
if (off_counter_out < 0)
goto out_release_master;
// configure SYNC signals for this slave
ecrt_slave_config_dc(sc, 0x0700, 1000000, 440000, 0, 0);
printk(KERN_INFO PFX "Activating master...\n");
if (ecrt_master_activate(master)) {
printk(KERN_ERR PFX "Failed to activate master!\n");
goto out_release_master;
}
// Get internal process data for domain
domain1_pd = ecrt_domain_data(domain1);
printk(KERN_INFO PFX "Starting cyclic sample thread...\n");
requested_ticks = nano2count(TIMERTICKS);
tick_period = start_rt_timer(requested_ticks);
printk(KERN_INFO PFX "RT timer started with %i/%i ticks.\n",
(int) tick_period, (int) requested_ticks);
if (rt_task_init(&task, run, 0, 2000, 0, 1, NULL)) {
printk(KERN_ERR PFX "Failed to init RTAI task!\n");
goto out_stop_timer;
}
now = rt_get_time();
if (rt_task_make_periodic(&task, now + tick_period, tick_period)) {
printk(KERN_ERR PFX "Failed to run RTAI task!\n");
goto out_stop_task;
}
printk(KERN_INFO PFX "Initialized.\n");
return 0;
out_stop_task:
rt_task_delete(&task);
out_stop_timer:
stop_rt_timer();
out_release_master:
printk(KERN_ERR PFX "Releasing master...\n");
ecrt_release_master(master);
out_return:
rt_sem_delete(&master_sem);
printk(KERN_ERR PFX "Failed to load. Aborting.\n");
return ret;
}
/*****************************************************************************/
void __exit cleanup_mod(void)
{
printk(KERN_INFO PFX "Stopping...\n");
rt_task_delete(&task);
stop_rt_timer();
ecrt_release_master(master);
rt_sem_delete(&master_sem);
printk(KERN_INFO PFX "Unloading.\n");
}
/*****************************************************************************/
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Florian Pose <fp@igh-essen.com>");
MODULE_DESCRIPTION("EtherCAT distributed clocks sample module");
module_init(init_mod);
module_exit(cleanup_mod);
/*****************************************************************************/