HAL SPI Interface

Hardware Abstraction Layer interface for SPI bus operations. More...

Functions
int	ove_hal_spi_open (ove_spi_t spi, const struct ove_spi_cfg *cfg)
	Configure and enable the SPI peripheral.
void	ove_hal_spi_close (ove_spi_t spi)
	Disable and release the SPI peripheral.
int	ove_hal_spi_transfer (ove_spi_t spi, const void *tx, void *rx, size_t len, uint64_t timeout_ns)
	Full-duplex SPI data transfer.
int	ove_hal_spi_transfer_async (ove_spi_t spi, const void *tx, void *rx, size_t len)
	Submit an async SPI transfer.
void	ove_spi_async_complete (ove_spi_t spi, int result)
	Completion notification from the HAL.

Detailed Description

Hardware Abstraction Layer interface for SPI bus operations.

Declares the low-level SPI functions that every platform HAL must implement. The portable SPI layer handles bus locking and chip-select management before delegating to these functions.

Function Documentation

ove_hal_spi_open()

int ove_hal_spi_open	(	ove_spi_t	spi,
		const struct ove_spi_cfg *	cfg
	)

Configure and enable the SPI peripheral.

Parameters

[in]	spi	SPI handle with storage already assigned.
[in]	cfg	Bus configuration descriptor.

Returns

OVE_OK on success, negative error code on failure.

ove_hal_spi_close()

void ove_hal_spi_close

(

ove_spi_t

spi

)

Disable and release the SPI peripheral.

Parameters

[in]

spi

SPI handle.

ove_hal_spi_transfer()

int ove_hal_spi_transfer	(	ove_spi_t	spi,
		const void *	tx,
		void *	rx,
		size_t	len,
		uint64_t	timeout_ns
	)

Full-duplex SPI data transfer.

Called under the bus mutex, with CS already asserted by the portable layer. tx or rx may be NULL for half-duplex.

Parameters

[in]	spi	SPI handle.
[in]	tx	Transmit buffer, or NULL.
[out]	rx	Receive buffer, or NULL.
[in]	len	Number of bytes to transfer.
[in]	timeout_ns	Maximum wait time.

Returns

OVE_OK on success, negative error code on failure.

ove_hal_spi_transfer_async()

int ove_hal_spi_transfer_async	(	ove_spi_t	spi,
		const void *	tx,
		void *	rx,
		size_t	len
	)

Submit an async SPI transfer.

Optional HAL hook. The portable layer calls this only when CONFIG_OVE_ASYNC is enabled. CS is asserted by the portable layer beforehand.

Backends must call ove_spi_async_complete with the transfer result when the operation finishes. The portable layer then deasserts CS, clears the busy flag, and invokes the user callback.

Backends without native DMA support may implement this via a worker thread (POSIX/NuttX), Zephyr signal API, or return OVE_ERR_NOT_SUPPORTED in zero-heap modes that cannot allocate the worker resources.

Parameters

[in]	spi	SPI handle (transfer params can be stashed in the pending_tx / pending_rx / pending_len storage fields when the HAL needs to defer the work).
[in]	tx	Transmit buffer (may be NULL for read-only).
[in]	rx	Receive buffer (may be NULL for write-only).
[in]	len	Bytes to transfer.

Returns

OVE_OK if accepted, negative error code on submission failure (no completion in that case).

ove_spi_async_complete()

void ove_spi_async_complete	(	ove_spi_t	spi,
		int	result
	)

Completion notification from the HAL.

Called by the HAL backend (from worker thread or DMA ISR) when an async transfer finishes. The portable layer takes care of CS deassert, busy-flag clear, and user callback dispatch.

Safe to call from ISR context (no mutex unlock, no allocation).

Parameters

[in]	spi	SPI handle the transfer was submitted on.
[in]	result	OVE_OK on success, negative error code on failure.