Send timeout is set to 10 ms. Without timeout PLC can be blocked by CAN driver: if CAN bus is not connected to controller CAN driver never returns and therfore PLC application halts. This is a temporary solution.
/*
This file is part of CanFestival, a library implementing CanOpen Stack.
Copyright (C): Edouard TISSERANT and Francis DUPIN
See COPYING file for copyrights details.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __KERNEL__
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#else
#include <linux/module.h>
#include <linux/delay.h>
#endif
#ifndef NOT_USE_DYNAMIC_LOADING
#define DLL_CALL(funcname) (* funcname##_driver)
#define FCT_PTR_INIT =NULL
#define DLSYM(name)\
*(void **) (&name##_driver) = dlsym(handle, #name"_driver");\
if ((error = dlerror()) != NULL) {\
fprintf (stderr, "%s\n", error);\
UnLoadCanDriver(handle);\
return NULL;\
}
#else /*NOT_USE_DYNAMIC_LOADING*/
/*Function call is direct*/
#define DLL_CALL(funcname) funcname##_driver
#endif /*NOT_USE_DYNAMIC_LOADING*/
#include "data.h"
#include "canfestival.h"
#include "timers_driver.h"
#define MAX_NB_CAN_PORTS 16
/** CAN port structure */
typedef struct {
char used; /**< flag indicating CAN port usage, will be used to abort Receiver task*/
CAN_HANDLE fd; /**< CAN port file descriptor*/
TASK_HANDLE receiveTask; /**< CAN Receiver task*/
CO_Data* d; /**< CAN object data*/
} CANPort;
#include "can_driver.h"
CANPort canports[MAX_NB_CAN_PORTS] = {{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,},{0,}};
#ifndef NOT_USE_DYNAMIC_LOADING
/*UnLoads the dll*/
UNS8 UnLoadCanDriver(LIB_HANDLE handle)
{
if(handle!=NULL)
{
dlclose(handle);
handle=NULL;
return 0;
}
return -1;
}
/**
* Loads the dll and get funcs ptr
*
* @param driver_name String containing driver's dynamic library name
* @return Library handle
*/
LIB_HANDLE LoadCanDriver(const char* driver_name)
{
LIB_HANDLE handle = NULL;
char *error;
if(handle==NULL)
{
handle = dlopen(driver_name, RTLD_LAZY);
}
if (!handle) {
fprintf (stderr, "%s\n", dlerror());
return NULL;
}
/*Get function ptr*/
DLSYM(canReceive)
DLSYM(canSend)
DLSYM(canOpen)
DLSYM(canChangeBaudRate)
DLSYM(canClose)
return handle;
}
#endif
/**
* CAN send routine
* @param port CAN port
* @param m CAN message
* @return success or error
*/
UNS8 canSend(CAN_PORT port, Message *m)
{
if(port){
UNS8 res;
//LeaveMutex();
res = DLL_CALL(canSend)(((CANPort*)port)->fd, m);
//EnterMutex();
return res; // OK
}
return 1; // NOT OK
}
/**
* CAN Receiver Task
* @param port CAN port
*/
void canReceiveLoop(CAN_PORT port)
{
Message m;
while (((CANPort*)port)->used) {
if (DLL_CALL(canReceive)(((CANPort*)port)->fd, &m) != 0)
break;
EnterMutex();
canDispatch(((CANPort*)port)->d, &m);
LeaveMutex();
}
}
/**
* CAN open routine
* @param board device name and baudrate
* @param d CAN object data
* @return valid CAN_PORT pointer or NULL
*/
CAN_PORT canOpen(s_BOARD *board, CO_Data * d)
{
int i;
for(i=0; i < MAX_NB_CAN_PORTS; i++)
{
if(!canports[i].used)
break;
}
#ifndef NOT_USE_DYNAMIC_LOADING
if (&DLL_CALL(canOpen)==NULL) {
fprintf(stderr,"CanOpen : Can Driver dll not loaded\n");
return NULL;
}
#endif
CAN_HANDLE fd0 = DLL_CALL(canOpen)(board);
if(fd0){
canports[i].used = 1;
canports[i].fd = fd0;
canports[i].d = d;
d->canHandle = (CAN_PORT)&canports[i];
CreateReceiveTask(&(canports[i]), &canports[i].receiveTask, &canReceiveLoop);
return (CAN_PORT)&canports[i];
}else{
MSG("CanOpen : Cannot open board {busname='%s',baudrate='%s'}\n",board->busname, board->baudrate);
return NULL;
}
}
/**
* CAN close routine
* @param d CAN object data
* @return success or error
*/
int canClose(CO_Data * d)
{
int res = 0;
CANPort* port = (CANPort*)d->canHandle;
if(port){
((CANPort*)d->canHandle)->used = 0;
res = DLL_CALL(canClose)(port->fd);
WaitReceiveTaskEnd(&port->receiveTask);
d->canHandle = NULL;
}
return res;
}
/**
* CAN change baudrate routine
* @param port CAN port
* @param baud baudrate
* @return success or error
*/
UNS8 canChangeBaudRate(CAN_PORT port, char* baud)
{
if(port){
UNS8 res;
//LeaveMutex();
res = DLL_CALL(canChangeBaudRate)(((CANPort*)port)->fd, baud);
//EnterMutex();
return res; // OK
}
return 1; // NOT OK
}
#ifdef __KERNEL__
EXPORT_SYMBOL (canOpen);
EXPORT_SYMBOL (canClose);
EXPORT_SYMBOL (canSend);
EXPORT_SYMBOL (canChangeBaudRate);
#endif