can.h File Reference

#include "utils/common.h"
#include "jbus/j1939_struct.h"
#include <string>

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Functions
void	can_init (int argc, char *argv[], resmgr_connect_funcs_t *pconn, resmgr_io_funcs_t *pio, IOFUNC_ATTR_T *pattr)
int	can_set_filter (int fd, unsigned long id, unsigned long mask)
int	can_empty_queue (int fd)
int	can_arm (int fd, int channel_id)
int	can_read (intptr_t fd, unsigned long *id, char *extended, void *data, BYTE size)
int	can_write (intptr_t fd, unsigned long id, char extended, void *data, BYTE size)
int	can_send (int fd, j1939_pdu_typ *pdu)

Detailed Description

can.h

This file contains utility methods needed to read and write messages to the Control Area Network (CAN) card.

Author

Abdul Rahman Kreidieh

Version

1.0.0

Date

January 14, 2019

Function Documentation

can_arm()

int can_arm	(	int	fd,
		int	channel_id
	)

Enable pulses from the CAN driver to the client process.

Pulses are waited for with MsgReceive or IP_Receive. Internal to the driver, done as part of open for read.

Parameters

fd	file descriptor for the location of the CAN card
channel_id	The ID of the channel that can be used to receive messages and pulses

Returns

EOK - Success.
EAGAIN - The devctl() command couldn't be completed because the device driver was in use by another process, or the driver was unable to carry out the request due to an outstanding command in progress.
EBADF - Invalid open file descriptor, filedes.
EINTR - The devctl() function was interrupted by a signal.
EINVAL - The device driver detected an error in dev_data_ptr or n_bytes.
EIO - The devctl() function couldn't complete because of a hardware error.
ENOSYS - The device doesn't support the dcmd command.
ENOTTY - The dcmd argument isn't a valid command for this device.
EPERM - The process doesn't have sufficient permission to carry out the requested command.

can_empty_queue()

int can_empty_queue

(

int

fd

)

Empty the queue of messages in the CAN driver.

This is internal to the driver, and done as part of open for read

Parameters

fd	file descriptor for the location of the CAN card

Returns

number of messages that were dropped from the queue

can_init()

void can_init	(	int	argc,
		char *	argv[],
		resmgr_connect_funcs_t *	pconn,
		resmgr_io_funcs_t *	pio,
		IOFUNC_ATTR_T *	pattr
	)

Initialize the CAN driver.

This function is called from the main() during the initialization of the CAN driver to read the .ini file and initialize the can_info structure, and initialize the function tables.

Additional Arguments:

• -e: specifies extended frame
• -f: specifies whether to create a copy of pconfig (not modify the original)
• -i: interrupt request line
• -n: device name
• -p: port
• -s: bit speed
• -v: verbose

Parameters

argc	see additional arguments
argv	see additional arguments
pconn	table of the POSIX-level connect functions that are used by a resource manager. The open handle is updated to support opening the CAN card port
pio	table of the POSIX-level I/O functions that are used by a resource manager. The devctl handle is updated to support interrupt handling on the CAN card port
pattr	pointer to information per device manager

can_read()

int can_read	(	intptr_t	fd,
		unsigned long *	id,
		char *	extended,
		void *	data,
		BYTE	size
	)

Read information from the CAN card.

This message will update the ID, message format, and data field of a CAN message.

Parameters

fd	file descriptor for the location of the CAN card
id	CAN message format ID
extended	updated to be 1 if the identifier is in extended (29 bit) format, 0 if it is in the unextended (11 bit) format
data	the content of the data field. This element will be modified by this method.
size	number of bytes in the CAN data field

Returns

number of bytes in the data segment; -1 if error encountered

can_send()

int can_send	(	int	fd,
		j1939_pdu_typ *	pdu
	)

FIXME (merge with can_write)

PATH CAN driver does not yet use state code or slot arguments, provided for compatibility with B&B STB converter send routine.

Parameters

fd	file descriptor that is used when sending the message
pdu	message to send

Returns

0 on error, 1 on success.

can_set_filter()

int can_set_filter	(	int	fd,
		unsigned long	id,
		unsigned long	mask
	)

Set the CAN filter.

Internal to the driver, set as part of open for read

Parameters

fd	file descriptor for the location of the CAN card
id	CAN message format ID (standard or extended)
mask	requested filter mask

Returns

EOK - Success.
EAGAIN - The devctl() command couldn't be completed because the device driver was in use by another process, or the driver was unable to carry out the request due to an outstanding command in progress.
EBADF - Invalid open file descriptor, filedes.
EINTR - The devctl() function was interrupted by a signal.
EINVAL - The device driver detected an error in dev_data_ptr or n_bytes.
EIO - The devctl() function couldn't complete because of a hardware error.
ENOSYS - The device doesn't support the dcmd command.
ENOTTY - The dcmd argument isn't a valid command for this device.
EPERM - The process doesn't have sufficient permission to carry out the requested command.

can_write()

int can_write	(	intptr_t	fd,
		unsigned long	id,
		char	extended,
		void *	data,
		BYTE	size
	)

Write information to the CAN card.

Parameters

fd	file descriptor for the location of the CAN card
id	CAN device id on bus
extended	0 for standard (11 bit) format, 1 for extended (29 bit) format
data	the content of the data field
size	number of bytes to be added to the data field

Returns

EOK - Success.
EAGAIN - The devctl() command couldn't be completed because the device driver was in use by another process, or the driver was unable to carry out the request due to an outstanding command in progress.
EBADF - Invalid open file descriptor, filedes.
EINTR - The devctl() function was interrupted by a signal.
EINVAL - The device driver detected an error in dev_data_ptr or n_bytes.
EIO - The devctl() function couldn't complete because of a hardware error.
ENOSYS - The device doesn't support the dcmd command.
ENOTTY - The dcmd argument isn't a valid command for this device.
EPERM - The process doesn't have sufficient permission to carry out the requested command.