uart_async_rx.h File Reference

Helper module for receiving using UART Asynchronous API. More...

#include <zephyr/kernel.h>

Go to the source code of this file.

Data Structures
struct	uart_async_rx_buf
struct	uart_async_rx
	UART asynchronous RX helper structure. More...
struct	uart_async_rx_config
	UART asynchronous RX helper configuration structure. More...

Macros
#define	UART_ASYNC_RX_BUF_OVERHEAD   offsetof(struct uart_async_rx_buf, buffer)
	Get amount of space dedicated for managing each buffer state.

Functions
static uint8_t	uart_async_rx_get_buf_len (struct uart_async_rx *async_rx)
	Get RX buffer length.
int	uart_async_rx_init (struct uart_async_rx *async_rx, const struct uart_async_rx_config *config)
	Initialize the helper instance.
void	uart_async_rx_reset (struct uart_async_rx *async_rx)
	Reset state of the helper instance.
void	uart_async_rx_on_rdy (struct uart_async_rx *async_rx, uint8_t *buffer, size_t length)
	Indicate received data.
uint8_t *	uart_async_rx_buf_req (struct uart_async_rx *async_rx)
	Get next RX buffer.
void	uart_async_rx_on_buf_rel (struct uart_async_rx *async_rx, uint8_t *buf)
	Indicate that buffer is no longer used by the UART driver.
size_t	uart_async_rx_data_claim (struct uart_async_rx *async_rx, uint8_t **data, size_t length)
	Claim received data for processing.
bool	uart_async_rx_data_consume (struct uart_async_rx *async_rx, size_t length)
	Consume claimed data.

Detailed Description

Helper module for receiving using UART Asynchronous API.

Macro Definition Documentation

UART_ASYNC_RX_BUF_OVERHEAD

#define UART_ASYNC_RX_BUF_OVERHEAD   offsetof(struct uart_async_rx_buf, buffer)

Get amount of space dedicated for managing each buffer state.

User buffer provided during the initialization is split into chunks and each chunk has overhead. This overhead can be used to calculate actual space used for UART data.

Returns

Overhead space in bytes.

Function Documentation

uart_async_rx_buf_req()

uint8_t * uart_async_rx_buf_req

(

struct uart_async_rx *

async_rx

)

Get next RX buffer.

Returned pointer shall be provided to uart_rx_buf_rsp or uart_rx_enable. If null is returned that indicates that there are no available buffers since all buffers are used by the driver or contain not consumed data.

Parameters

async_rx

Pointer to the helper instance.

Returns

Pointer to the next RX buffer or null if no buffer available.

uart_async_rx_data_claim()

size_t uart_async_rx_data_claim	(	struct uart_async_rx *	async_rx,
		uint8_t **	data,
		size_t	length
	)

Claim received data for processing.

Helper module works in the zero copy mode. It provides a pointer to the buffer that was directly used by the UART driver. Since received data is spread across multiple buffers there is no possibility to read all data at once. It can only be consumed in chunks. After data is processed, uart_async_rx_data_consume is used to indicate that data is consumed.

Parameters

async_rx	Pointer to the helper instance.
data	Location where address to the buffer is written. Untouched if no data to claim.
length	Amount of requested data.

Returns

Amount valid of data in the data buffer. 0 is returned when there is no data.

uart_async_rx_data_consume()

bool uart_async_rx_data_consume	(	struct uart_async_rx *	async_rx,
		size_t	length
	)

Consume claimed data.

It pairs with uart_async_rx_data_claim.

Parameters

async_rx	Pointer to the helper instance.
length	Amount of data to consume. It must be less or equal than amount of claimed data.

Return values

true	If there are free buffers in the pool after data got consumed.
false	If there are no free buffers.

uart_async_rx_get_buf_len()

static uint8_t uart_async_rx_get_buf_len ( struct uart_async_rx *  async_rx )

inlinestatic

Get RX buffer length.

Parameters

async_rx

Pointer to the helper instance.

Returns

Buffer length.

uart_async_rx_init()

int uart_async_rx_init	(	struct uart_async_rx *	async_rx,
		const struct uart_async_rx_config *	config
	)

Initialize the helper instance.

Parameters

async_rx	Pointer to the helper instance.
config	Configuration. Must be persistent.

Return values

0	on successful initialization.

uart_async_rx_on_buf_rel()

void uart_async_rx_on_buf_rel	(	struct uart_async_rx *	async_rx,
		uint8_t *	buf
	)

Indicate that buffer is no longer used by the UART driver.

Function shall be called on UART_RX_BUF_RELEASED event.

Parameters

async_rx	Pointer to the helper instance.
buf	Buffer pointer received in the UART driver event.

uart_async_rx_on_rdy()

void uart_async_rx_on_rdy	(	struct uart_async_rx *	async_rx,
		uint8_t *	buffer,
		size_t	length
	)

Indicate received data.

Function shall be called from UART_RX_RDY context.

Parameters

async_rx	Pointer to the helper instance.
buffer	Buffer received in the UART driver event.
length	Length received in the UART driver event.

uart_async_rx_reset()

void uart_async_rx_reset

(

struct uart_async_rx *

async_rx

)

Reset state of the helper instance.

Helper can be reset after RX abort to discard all received data and bring the helper to its initial state.

Parameters

async_rx

Pointer to the helper instance.