AT Interface

Detailed Description

Interface for AT communications.

Summary

The AT interface provides common APIs for AT HAL drivers. The AT interface supports the following features:

• Full-duplex AT communication
• Interrupt driven transmit/receive processing
• Callback function with returned event code

Data Structures
struct	atcmd_w_info_t
struct	atcmd_w_callback_args_t
struct	atcmd_w_cfg_t
struct	atcmd_w_api_t
struct	atcmd_w_instance_t

Typedefs
typedef void	atcmd_w_ctrl_t

Enumerations
enum	atcmd_w_event_t

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Data Structure Documentation

atcmd_w_info_t

struct atcmd_w_info_t

AT driver specific information

Data Fields
uint32_t	write_bytes_max	Maximum bytes that can be written at this time. Only applies if atcmd_w_cfg_t::p_transfer_tx is not NULL.
uint32_t	read_bytes_max	Maximum bytes that are available to read at one time. Only applies if atcmd_w_cfg_t::p_transfer_rx is not NULL.

atcmd_w_callback_args_t

struct atcmd_w_callback_args_t

AT Callback parameter definition

Data Fields
atcmd_w_event_t	event	Event code.
uint32_t	data	Contains the next character received for the events ATCMD_W_EVENT_RX_CHAR, ATCMD_W_EVENT_ERR_PARITY, ATCMD_W_EVENT_ERR_FRAMING, or ATCMD_W_EVENT_ERR_OVERFLOW. Otherwise unused.
char	at_data
char	at_buff[ATCMD_W_BUFF_MAX]
void const *	p_context	Context provided to user during callback.

atcmd_w_cfg_t

struct atcmd_w_cfg_t

AT Configuration

Data Fields
transfer_instance_t const *	p_transfer_rx
transfer_instance_t const *	p_transfer_tx
void(*	p_callback )(atcmd_w_callback_args_t *p_args)
	Pointer to callback function.
void const *	p_context
	User defined context passed into callback function.
void const *	p_extend
	AT hardware dependent configuration.

Field Documentation

p_transfer_rx

transfer_instance_t const* atcmd_w_cfg_t::p_transfer_rx

Optional transfer instance used to receive multiple bytes without interrupts. Set to NULL if unused. If NULL, the number of bytes allowed in the read API is limited to one byte at a time.

p_transfer_tx

transfer_instance_t const* atcmd_w_cfg_t::p_transfer_tx

Optional transfer instance used to send multiple bytes without interrupts. Set to NULL if unused. If NULL, the number of bytes allowed in the write APIs is limited to one byte at a time.

atcmd_w_api_t

struct atcmd_w_api_t

Shared Interface definition for AT

Data Fields
fsp_err_t(*	open )(atcmd_w_ctrl_t *const p_ctrl, atcmd_w_cfg_t const *const p_cfg)
fsp_err_t(*	read )(atcmd_w_ctrl_t *const p_ctrl, uint8_t *const p_dest, uint32_t const bytes)
fsp_err_t(*	write )(atcmd_w_ctrl_t *const p_ctrl, uint8_t const *const p_src, uint32_t const bytes)
fsp_err_t(*	infoGet )(atcmd_w_ctrl_t *const p_ctrl, atcmd_w_info_t *const p_info)
fsp_err_t(*	communicationAbort )(atcmd_w_ctrl_t *const p_ctrl)
fsp_err_t(*	callbackSet )(atcmd_w_ctrl_t *const p_ctrl, void(*p_callback)(atcmd_w_callback_args_t *), void const *const p_context, atcmd_w_callback_args_t *const p_callback_memory)
fsp_err_t(*	close )(atcmd_w_ctrl_t *const p_ctrl)
fsp_err_t(*	readStop )(atcmd_w_ctrl_t *const p_ctrl, uint32_t *remaining_bytes)

Field Documentation

open

fsp_err_t(* atcmd_w_api_t::open) (atcmd_w_ctrl_t *const p_ctrl, atcmd_w_cfg_t const *const p_cfg)

Open AT device.

Parameters

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

read

fsp_err_t(* atcmd_w_api_t::read) (atcmd_w_ctrl_t *const p_ctrl, uint8_t *const p_dest, uint32_t const bytes)

Read from AT device. The read buffer is used until the read is complete. When a transfer is complete, the callback is called with event ATCMD_W_EVENT_RX_COMPLETE. Bytes received outside an active transfer are received in the callback function with event ATCMD_W_EVENT_RX_CHAR. The maximum transfer size is reported by infoGet().

Parameters

[in]	p_ctrl	Pointer to the AT control block for the channel.
[in]	p_dest	Destination address to read data from.
[in]	bytes	Read data length.

write

fsp_err_t(* atcmd_w_api_t::write) (atcmd_w_ctrl_t *const p_ctrl, uint8_t const *const p_src, uint32_t const bytes)

Write to AT device. The write buffer is used until write is complete. Do not overwrite write buffer contents until the write is finished. When the write is complete (all bytes are fully transmitted on the wire), the callback called with event ATCMD_W_EVENT_TX_COMPLETE. The maximum transfer size is reported by infoGet().

Parameters

[in]	p_ctrl	Pointer to the AT control block.
[in]	p_src	Source address to write data to.
[in]	bytes	Write data length.

infoGet

fsp_err_t(* atcmd_w_api_t::infoGet) (atcmd_w_ctrl_t *const p_ctrl, atcmd_w_info_t *const p_info)

Get the driver specific information.

Parameters

[in]	p_ctrl	Pointer to the AT control block.
[in]	baudrate	Baud rate in bps.

communicationAbort

fsp_err_t(* atcmd_w_api_t::communicationAbort) (atcmd_w_ctrl_t *const p_ctrl)

Abort ongoing transfer.

Parameters

[in]

p_ctrl

Pointer to the AT control block.

callbackSet

fsp_err_t(* atcmd_w_api_t::callbackSet) (atcmd_w_ctrl_t *const p_ctrl, void(*p_callback)(atcmd_w_callback_args_t *), void const *const p_context, atcmd_w_callback_args_t *const p_callback_memory)

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

Parameters

[in]	p_ctrl	Pointer to the AT control block.
[in]	p_callback	Callback function
[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.

close

fsp_err_t(* atcmd_w_api_t::close) (atcmd_w_ctrl_t *const p_ctrl)

Close AT device.

Parameters

[in]

p_ctrl

Pointer to the AT control block.

readStop

fsp_err_t(* atcmd_w_api_t::readStop) (atcmd_w_ctrl_t *const p_ctrl, uint32_t *remaining_bytes)

Stop ongoing read and return the number of bytes remaining in the read.

Parameters

[in]	p_ctrl	Pointer to the AT control block.
[in,out]	remaining_bytes	Pointer to location to store remaining bytes for read.

atcmd_w_instance_t

struct atcmd_w_instance_t

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

Data Fields
atcmd_w_ctrl_t *	p_ctrl	Pointer to the control structure for this instance.
atcmd_w_cfg_t const *	p_cfg	Pointer to the configuration structure for this instance.
atcmd_w_api_t const *	p_api	Pointer to the API structure for this instance.

Typedef Documentation

atcmd_w_ctrl_t

typedef void atcmd_w_ctrl_t

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

Enumeration Type Documentation

atcmd_w_event_t

enum atcmd_w_event_t

AT Event codes

Enumerator
ATCMD_W_EVENT_RX_COMPLETE	Receive complete event.
ATCMD_W_EVENT_TX_COMPLETE	Transmit complete event.
ATCMD_W_EVENT_RX_CHAR	Character received.
ATCMD_W_EVENT_ERR_PARITY	Parity error event.
ATCMD_W_EVENT_ERR_FRAMING	Mode fault error event.
ATCMD_W_EVENT_ERR_OVERFLOW	FIFO Overflow error event.
ATCMD_W_EVENT_BREAK_DETECT	Break detect error event.
ATCMD_W_EVENT_TX_DATA_EMPTY	Last byte is transmitting, ready for more data.