UART

UART serial bus driver. More...

Data Structures
struct	ove_uart_cfg
	UART configuration descriptor. More...

Enumerations
enum	ove_uart_parity_t { OVE_UART_PARITY_NONE = 0 , OVE_UART_PARITY_ODD = 1 , OVE_UART_PARITY_EVEN = 2 }
	UART parity mode.
enum	ove_uart_stop_t { OVE_UART_STOP_1 = 0 , OVE_UART_STOP_1_5 = 1 , OVE_UART_STOP_2 = 2 }
	UART stop-bit count.
enum	ove_uart_flow_t { OVE_UART_FLOW_NONE = 0 , OVE_UART_FLOW_RTS_CTS = 1 }
	UART hardware flow control.

Functions
int	ove_uart_init (ove_uart_t *uart, ove_uart_storage_t *storage, void *rx_buf, const struct ove_uart_cfg *cfg)
	Initialise a UART using caller-provided static storage.
void	ove_uart_deinit (ove_uart_t uart)
	Release a UART handle previously created with ove_uart_init.
int	ove_uart_create (ove_uart_t *uart, const struct ove_uart_cfg *cfg)
	Heap-mode counterpart of ove_uart_init() — allocates storage and RX buffer.
void	ove_uart_destroy (ove_uart_t uart)
	Destroy a UART handle previously created with ove_uart_create.
int	ove_uart_write (ove_uart_t uart, const void *data, size_t len, uint64_t timeout_ns, size_t *bytes_written)
	Write data to the UART.
int	ove_uart_read (ove_uart_t uart, void *buf, size_t len, uint64_t timeout_ns, size_t *bytes_read)
	Read data from the UART RX buffer.
size_t	ove_uart_bytes_available (ove_uart_t uart)
	Query the number of bytes available in the RX buffer.
int	ove_uart_flush (ove_uart_t uart)
	Flush the TX hardware buffer.
void	ove_uart_rx_isr_push (ove_uart_t uart, const void *data, size_t len)
	Push received bytes from ISR into the portable RX buffer.
int	ove_uart_set_rx_notify (ove_uart_t uart, ove_notify_cb cb, void *user_data)
	Register a notify callback fired after every byte (or chunk) received into the RX buffer.

Detailed Description

UART serial bus driver.

Provides a portable, multi-instance UART API with configurable baud rate and framing, interrupt-driven RX buffering, thread-safe TX, and blocking read/write with timeout.

RX bytes are buffered internally via an Stream. Backend ISR handlers push received bytes through ove_uart_rx_isr_push() which the portable layer provides.

Two allocation strategies are supported:

• _create() / _destroy() — heap-allocated. Available only when OVE_HEAP_UART is defined (i.e. CONFIG_OVE_ZERO_HEAP is not set).
• _init() / _deinit() — caller-supplied storage and RX buffer. Available in both modes. See OVE_UART_DEFINE_STATIC for a one-step static helper.

Note

Requires CONFIG_OVE_UART.

Function Documentation

ove_uart_init()

int ove_uart_init	(	ove_uart_t *	uart,
		ove_uart_storage_t *	storage,
		void *	rx_buf,
		const struct ove_uart_cfg *	cfg
	)

Initialise a UART using caller-provided static storage.

Parameters

[out]	uart	Receives the initialised UART handle.
[in]	storage	Pointer to statically-allocated UART storage.
[in]	rx_buf	Caller-supplied RX ring buffer.
[in]	cfg	UART configuration descriptor.

Returns

OVE_OK on success, negative error code on failure.

ove_uart_create()

int ove_uart_create	(	ove_uart_t *	uart,
		const struct ove_uart_cfg *	cfg
	)

Heap-mode counterpart of ove_uart_init() — allocates storage and RX buffer.

Parameters

[out]	uart	Receives the initialised handle.
[in]	cfg	UART configuration descriptor.

Returns

OVE_OK on success, negative error code on failure.

ove_uart_write()

int ove_uart_write	(	ove_uart_t	uart,
		const void *	data,
		size_t	len,
		uint64_t	timeout_ns,
		size_t *	bytes_written
	)

Write data to the UART.

Thread-safe (internal TX mutex). On success bytes_written holds the number of bytes actually accepted, which **may be less than len** on a short write — callers that require all bytes must check it and resubmit the remainder; OVE_OK alone does not guarantee a full write.

Note

timeout_ns is best-effort and is currently ignored by several backends (the posix/zephyr/freertos TX paths transmit synchronously); do not rely on it to bound a write.

Parameters

[in]	uart	UART handle.
[in]	data	Data to transmit.
[in]	len	Number of bytes to write.
[in]	timeout_ns	Maximum wait time (best-effort; see note).
[out]	bytes_written	Actual bytes written (may be < len), or NULL.

Returns

OVE_OK on success, negative error code on failure.

ove_uart_read()

int ove_uart_read	(	ove_uart_t	uart,
		void *	buf,
		size_t	len,
		uint64_t	timeout_ns,
		size_t *	bytes_read
	)

Read data from the UART RX buffer.

Blocks for up to timeout_ns until at least 1 byte is available.

Parameters

[in]	uart	UART handle.
[out]	buf	Buffer to receive data.
[in]	len	Maximum bytes to read.
[in]	timeout_ns	Maximum wait time.
[out]	bytes_read	Actual bytes read, or NULL.

Returns

OVE_OK on success, negative error code on failure.

ove_uart_bytes_available()

size_t ove_uart_bytes_available

(

ove_uart_t

uart

)

Query the number of bytes available in the RX buffer.

Parameters

[in]

uart

UART handle.

Returns

Number of bytes available, or 0 if empty or invalid.

ove_uart_flush()

int ove_uart_flush

(

ove_uart_t

uart

)

Flush the TX hardware buffer.

Blocks until all pending TX bytes have been physically transmitted.

Parameters

[in]

uart

UART handle.

Returns

OVE_OK on success, negative error code on failure.

ove_uart_rx_isr_push()

void ove_uart_rx_isr_push	(	ove_uart_t	uart,
		const void *	data,
		size_t	len
	)

Push received bytes from ISR into the portable RX buffer.

Backend UART ISR handlers call this function to deliver received bytes to the portable layer's internal Stream.

Parameters

[in]	uart	UART handle.
[in]	data	Pointer to received byte(s).
[in]	len	Number of bytes received.

ove_uart_set_rx_notify()

int ove_uart_set_rx_notify	(	ove_uart_t	uart,
		ove_notify_cb	cb,
		void *	user_data
	)

Register a notify callback fired after every byte (or chunk) received into the RX buffer.

Convenience delegate to ove_stream_set_notify on the UART's internal RX stream — exposes the wake hook without leaking the stream handle itself. Designed for the Rust binding's async Uart::read().await path, which registers an AtomicWaker::wake trampoline here.

The callback fires from whatever context the byte was pushed in — typically an ISR via ove_uart_rx_isr_push. Must be non-blocking and ISR-safe.

Parameters

[in]	uart	UART handle.
[in]	cb	Callback to invoke after each RX, or NULL.
[in]	user_data	Opaque pointer forwarded to cb.

Returns

OVE_OK on success, negative error code on failure.