drivers/can_serial/can_serial.c
author Robert Lehmann <robert.lehmann@sitec-systems.de>
Tue, 28 Jul 2015 16:36:55 +0200
changeset 793 72e9e1064432
parent 631 08b6b903f84a
permissions -rw-r--r--
timers_unix: Fix termination problem of WaitReceiveTaskEnd

The function pthread_kill sends the Signal thread and to the own process.
If you use this construct than the application which calls uses the
canfestival api will terminate at the call of canClose. To avoid that
use pthread_cancel instead of pthread_kill. To use the pthread_cancel call
you need to set the cancel ability in the thread function. That means
you need to call pthread_setcancelstate and pthread_setcanceltype.
For the termination of the thread at any time it is important to set the
cancel type to PTHREAD_CANCEL_ASYNCHRONOUS.
/*
This file is part of CanFestival, a library implementing CanOpen Stack. 

Copyright (C): Edouard TISSERANT and Francis DUPIN

Ruthlessly butchered by James Steward to produce a serial (tty) port
driver.

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
*/

/*
	Single serial port CAN driver.
*/

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <termios.h>
#include <stdlib.h>

#define NEED_PRINT_MESSAGE
#include "can_driver.h"
#include "def.h"

typedef struct {
	int fd;
	struct termios old_termio, new_termio;
} CANPort;

/*********functions which permit to communicate with the board****************/
UNS8 canReceive_driver(CAN_HANDLE fd0, Message * m)
{
	int rv, N, n = 0;
	fd_set rfds;
	struct timeval tv;

	N = 4; //initially try to read 4 bytes, including the length byte
	
retry:
	rv = read(((CANPort *) fd0)->fd, &((char *)m)[n], N - n);

	if (rv == -1) {
		fprintf(stderr, "read: %s\n", strerror(errno));
		return 1;
	}

	n += rv;

	if (n == 4) {
		N = (4 + m->len);
		
		if (m->len > 8) {
			fprintf(stderr, "Warning: invalid message length %d\n", 
					m->len);
			
			//try to resync
			n = 0;
			N = 4;
		}

	}

	if (n < N) {

		FD_ZERO(&rfds);
		FD_SET(((CANPort *) fd0)->fd, &rfds);

		tv.tv_sec = 0;
		tv.tv_usec=100000;
		
		rv = select(((CANPort *) fd0)->fd + 1, &rfds, NULL, NULL, &tv);
		if (rv == -1) {
			fprintf(stderr, "select: %s\n", strerror(errno));
			return 1;
		} else if (rv == 0) {
			n = 0;
		}

		goto retry;	
	}

	print_message(m);

	return 0;
}

/***************************************************************************/
UNS8 canSend_driver(CAN_HANDLE fd0, Message const * m)
{
	int rv;

	print_message(m);

	// Send to serial port 
	rv = write(((CANPort *) fd0)->fd, m, 4 + m->len);

	if (rv != 4 + m->len) {
		return 1;
	}

	return 0;
}

/***************************************************************************/
int TranslateBaudRate(char *optarg)
{
	if (!strcmp(optarg, "1M"))
		return (int) 1000;
	if (!strcmp(optarg, "500K"))
		return (int) 500;
	if (!strcmp(optarg, "250K"))
		return (int) 250;
	if (!strcmp(optarg, "125K"))
		return (int) 125;
	if (!strcmp(optarg, "100K"))
		return (int) 100;
	if (!strcmp(optarg, "50K"))
		return (int) 50;
	if (!strcmp(optarg, "20K"))
		return (int) 20;
	if (!strcmp(optarg, "10K"))
		return (int) 10;
	if (!strcmp(optarg, "5K"))
		return (int) 5;
	if (!strcmp(optarg, "none"))
		return 0;
	return 0x0000;
}

UNS8 canChangeBaudRate_driver(CAN_HANDLE fd0, char *baud)
{
	printf("Faked changing to baud rate %s[%d]\n", 
			baud, TranslateBaudRate(baud));
	return 0;
}

/***************************************************************************/
CAN_HANDLE canOpen_driver(s_BOARD * board)
{
	int rv;

	CANPort *p;

	p = (CANPort *)calloc(1, sizeof(CANPort));
	
	if (p == NULL) {
		fprintf(stderr, "calloc: %s\n", strerror(errno));
		return (CAN_HANDLE) NULL;
	}

	p->fd = open(board->busname, O_RDWR);
	
	if (p->fd < 0) {
		fprintf(stderr, "open: %s, %s\n", 
				board->busname, strerror(errno));
		free(p);
		return (CAN_HANDLE) NULL;
	}

	if (tcgetattr(p->fd, &p->old_termio) != 0) {
		fprintf(stderr, "tcgetattr: %s, %s\n", 
				board->busname, strerror(errno));
		close(p->fd);
		free(p);
		return (CAN_HANDLE) NULL;
	}

	memcpy(&p->new_termio, &p->old_termio, 
					sizeof(p->old_termio));
	cfmakeraw(&p->new_termio);
	cfsetispeed(&p->new_termio, B115200);
	cfsetospeed(&p->new_termio, B115200);
	tcsetattr(p->fd, TCSANOW, &p->new_termio);

	return (CAN_HANDLE) p;
}

/***************************************************************************/
int canClose_driver(CAN_HANDLE fd0)
{
	if ((CANPort *) fd0 && ((CANPort *) fd0)->fd >= 0) {
		tcsetattr(((CANPort *) fd0)->fd, TCSANOW, 
					&((CANPort *) fd0)->old_termio);
		close(((CANPort *) fd0)->fd);
		free((CANPort *) fd0);
	}

	return 0;
}

int canfd_driver(CAN_HANDLE fd0)
{
	if ((CANPort *) fd0) {
		return ((CANPort *) fd0)->fd;
	}

	return -1;
}