CAN Interface

Detailed Description

Interface for CAN peripheral.

Summary

The CAN interface provides common APIs for CAN HAL drivers. CAN interface supports following features.

• Full-duplex CAN communication
• Generic CAN parameter setting
• Interrupt driven transmit/receive processing
• Callback function support with returning event code
• Hardware resource locking during a transaction

Data Structures
struct	can_info_t
struct	can_bit_timing_cfg_t
struct	can_frame_t
struct	can_callback_args_t
struct	can_cfg_t
struct	can_api_t
struct	can_instance_t

Typedefs
typedef void	can_ctrl_t

Enumerations
enum	can_event_t
enum	can_operation_mode_t
enum	can_test_mode_t
enum	can_id_mode_t
enum	can_frame_type_t

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Data Structure Documentation

can_info_t

struct can_info_t

CAN status info

Data Fields
uint32_t	status	Useful information from the CAN status register.
uint32_t	rx_mb_status	RX Message Buffer New Data flags.
uint32_t	rx_fifo_status	RX FIFO Empty flags.
uint8_t	error_count_transmit	Transmit error count.
uint8_t	error_count_receive	Receive error count.
uint32_t	error_code	Error code, cleared after reading.

can_bit_timing_cfg_t

struct can_bit_timing_cfg_t

CAN bit rate configuration.

Data Fields
uint32_t	baud_rate_prescaler	Baud rate prescaler. Valid values: 1 - 1024.
uint32_t	time_segment_1	Time segment 1 control.
uint32_t	time_segment_2	Time segment 2 control.
uint32_t	synchronization_jump_width	Synchronization jump width.

can_frame_t

struct can_frame_t

CAN data Frame

Data Fields
uint32_t	id	CAN ID.
can_id_mode_t	id_mode	Standard or Extended ID (IDE).
can_frame_type_t	type	Frame type (RTR).
uint8_t	data_length_code	CAN Data Length Code (DLC).
uint32_t	options	Implementation-specific options.
uint8_t	data[CAN_DATA_BUFFER_LENGTH]	CAN data.

can_callback_args_t

struct can_callback_args_t

CAN callback parameter definition

Data Fields
uint32_t	channel	Device channel number.
can_event_t	event	Event code.
uint32_t	error	Error code.
union can_callback_args_t	__unnamed__
void const *	p_context	Context provided to user during callback.
can_frame_t	frame	Received frame data.

can_cfg_t

struct can_cfg_t

CAN Configuration

Data Fields
uint32_t	channel
	CAN channel.
can_bit_timing_cfg_t *	p_bit_timing
	CAN bit timing.
void(*	p_callback )(can_callback_args_t *p_args)
	Pointer to callback function.
void const *	p_context
	User defined callback context.
void const *	p_extend
	CAN hardware dependent configuration.
uint8_t	ipl
	Error/Transmit/Receive interrupt priority.
IRQn_Type	error_irq
	Error IRQ number.
IRQn_Type	rx_irq
	Receive IRQ number.
IRQn_Type	tx_irq
	Transmit IRQ number.

can_api_t

struct can_api_t

Shared Interface definition for CAN

Data Fields
fsp_err_t(*	open )(can_ctrl_t *const p_ctrl, can_cfg_t const *const p_cfg)
fsp_err_t(*	write )(can_ctrl_t *const p_ctrl, uint32_t buffer_number, can_frame_t *const p_frame)
fsp_err_t(*	read )(can_ctrl_t *const p_ctrl, uint32_t buffer_number, can_frame_t *const p_frame)
fsp_err_t(*	close )(can_ctrl_t *const p_ctrl)
fsp_err_t(*	modeTransition )(can_ctrl_t *const p_ctrl, can_operation_mode_t operation_mode, can_test_mode_t test_mode)
fsp_err_t(*	infoGet )(can_ctrl_t *const p_ctrl, can_info_t *const p_info)
fsp_err_t(*	callbackSet )(can_ctrl_t *const p_ctrl, void(*p_callback)(can_callback_args_t *), void const *const p_context, can_callback_args_t *const p_callback_memory)

Field Documentation

open

fsp_err_t(* can_api_t::open) (can_ctrl_t *const p_ctrl, can_cfg_t const *const p_cfg)

Open function for CAN device

Parameters

[in,out]	p_ctrl	Pointer to the CAN control block. Must be declared by user. Value set here.
[in]	p_cfg	Pointer to CAN configuration structure. All elements of this structure must be set by user.

write

fsp_err_t(* can_api_t::write) (can_ctrl_t *const p_ctrl, uint32_t buffer_number, can_frame_t *const p_frame)

Write function for CAN device

Parameters

[in]	p_ctrl	Pointer to the CAN control block.
[in]	buffer	Buffer number (mailbox or message buffer) to write to.
[in]	p_frame	Pointer for frame of CAN ID, DLC, data and frame type to write.

read

fsp_err_t(* can_api_t::read) (can_ctrl_t *const p_ctrl, uint32_t buffer_number, can_frame_t *const p_frame)

Read function for CAN device

Parameters

[in]	p_ctrl	Pointer to the CAN control block.
[in]	buffer	Message buffer (number) to read from.
[in]	p_frame	Pointer to store the CAN ID, DLC, data and frame type.

close

fsp_err_t(* can_api_t::close) (can_ctrl_t *const p_ctrl)

Close function for CAN device

Parameters

[in]

p_ctrl

Pointer to the CAN control block.

modeTransition

fsp_err_t(* can_api_t::modeTransition) (can_ctrl_t *const p_ctrl, can_operation_mode_t operation_mode, can_test_mode_t test_mode)

Mode Transition function for CAN device

Parameters

[in]	p_ctrl	Pointer to the CAN control block.
[in]	operation_mode	Destination CAN operation state.
[in]	test_mode	Destination CAN test state.

infoGet

fsp_err_t(* can_api_t::infoGet) (can_ctrl_t *const p_ctrl, can_info_t *const p_info)

Get CAN channel info.

Parameters

[in]	p_ctrl	Handle for channel (pointer to channel control block)
[out]	p_info	Memory address to return channel specific data to.

callbackSet

fsp_err_t(* can_api_t::callbackSet) (can_ctrl_t *const p_ctrl, void(*p_callback)(can_callback_args_t *), void const *const p_context, can_callback_args_t *const p_callback_memory)

Specify callback function and optional context pointer and working memory pointer.

Parameters

[in]	p_ctrl	Control block set in can_api_t::open call.
[in]	p_callback	Callback function to register
[in]	p_context	Pointer to send to callback function
[in]	p_working_memory	Pointer to volatile memory where callback structure can be allocated. Callback arguments allocated here are only valid during the callback.

can_instance_t

struct can_instance_t

This structure encompasses everything that is needed to use an instance of this interface.

Data Fields
can_ctrl_t *	p_ctrl	Pointer to the control structure for this instance.
can_cfg_t const *	p_cfg	Pointer to the configuration structure for this instance.
can_api_t const *	p_api	Pointer to the API structure for this instance.

Typedef Documentation

can_ctrl_t

typedef void can_ctrl_t

CAN control block. Allocate an instance specific control block to pass into the CAN API calls.

Enumeration Type Documentation

can_event_t

enum can_event_t

CAN event codes

Enumerator
CAN_EVENT_ERR_WARNING	Error Warning event.
CAN_EVENT_ERR_PASSIVE	Error Passive event.
CAN_EVENT_ERR_BUS_OFF	Bus Off event.
CAN_EVENT_BUS_RECOVERY	Bus Off Recovery event.
CAN_EVENT_MAILBOX_MESSAGE_LOST	Mailbox has been overrun.
CAN_EVENT_ERR_BUS_LOCK	Bus lock detected (32 consecutive dominant bits).
CAN_EVENT_ERR_CHANNEL	Channel error has occurred.
CAN_EVENT_TX_ABORTED	Transmit abort event.
CAN_EVENT_RX_COMPLETE	Receive complete event.
CAN_EVENT_TX_COMPLETE	Transmit complete event.
CAN_EVENT_ERR_GLOBAL	Global error has occurred.
CAN_EVENT_TX_FIFO_EMPTY	Transmit FIFO is empty.
CAN_EVENT_FIFO_MESSAGE_LOST	Receive FIFO overrun.

can_operation_mode_t

enum can_operation_mode_t

CAN Operation modes

Enumerator
CAN_OPERATION_MODE_NORMAL	CAN Normal Operation Mode.
CAN_OPERATION_MODE_RESET	CAN Reset Operation Mode.
CAN_OPERATION_MODE_HALT	CAN Halt Operation Mode.
CAN_OPERATION_MODE_SLEEP	CAN Sleep Operation Mode.

can_test_mode_t

enum can_test_mode_t

CAN Test modes

Enumerator
CAN_TEST_MODE_DISABLED	CAN Test Mode Disabled.
CAN_TEST_MODE_LISTEN	CAN Test Listen Mode.
CAN_TEST_MODE_LOOPBACK_EXTERNAL	CAN Test External Loopback Mode.
CAN_TEST_MODE_LOOPBACK_INTERNAL	CAN Test Internal Loopback Mode.
CAN_TEST_MODE_INTERNAL_BUS	CANFD Internal CAN Bus Communication Test Mode.

can_id_mode_t

enum can_id_mode_t

CAN ID modes

Enumerator
CAN_ID_MODE_STANDARD	Standard IDs of 11 bits used.
CAN_ID_MODE_EXTENDED	Extended IDs of 29 bits used.

can_frame_type_t

enum can_frame_type_t

CAN frame types

Enumerator
CAN_FRAME_TYPE_DATA	Data frame.
CAN_FRAME_TYPE_REMOTE	Remote frame.