I2C bus master driver. More...

Data Structures
struct	ove_i2c_cfg
	I2C bus configuration descriptor. More...

Macros
#define	OVE_I2C_REG_WRITE_MAX 32

Enumerations
enum	ove_i2c_speed_t { OVE_I2C_SPEED_STANDARD = 0 , OVE_I2C_SPEED_FAST = 1 , OVE_I2C_SPEED_FAST_PLUS = 2 }
	I2C bus speed grade. More...

Functions
int	ove_i2c_init (ove_i2c_t i2c, ove_i2c_storage_t storage, const struct ove_i2c_cfg *cfg)
	Initialise an I2C bus using caller-provided static storage.

void	ove_i2c_deinit (ove_i2c_t i2c)
	Deinitialise a statically-allocated I2C bus.

int	ove_i2c_create (ove_i2c_t i2c, const struct ove_i2c_cfg cfg)
	Create a heap-allocated I2C bus controller.

void	ove_i2c_destroy (ove_i2c_t i2c)
	Destroy a heap-allocated I2C bus controller.

int	ove_i2c_write (ove_i2c_t i2c, uint16_t addr, const void *data, size_t len, uint64_t timeout_ns)
	Write data to an I2C device.

int	ove_i2c_read (ove_i2c_t i2c, uint16_t addr, void *buf, size_t len, uint64_t timeout_ns)
	Read data from an I2C device.

int	ove_i2c_write_read (ove_i2c_t i2c, uint16_t addr, const void tx, size_t tx_len, void rx, size_t rx_len, uint64_t timeout_ns)
	Combined write-then-read with I2C repeated start.

int	ove_i2c_reg_write (ove_i2c_t i2c, uint16_t addr, uint8_t reg, const void *data, size_t len, uint64_t timeout_ns)
	Write to a single-byte-addressed register.

int	ove_i2c_reg_read (ove_i2c_t i2c, uint16_t addr, uint8_t reg, void *buf, size_t len, uint64_t timeout_ns)
	Read from a single-byte-addressed register.

int	ove_i2c_probe (ove_i2c_t i2c, uint16_t addr, uint64_t timeout_ns)
	Probe for a device at the given address.

int	ove_i2c_write_read_async (ove_i2c_t i2c, uint16_t addr, const void tx, size_t tx_len, void rx, size_t rx_len, ove_dma_complete_cb cb, void *user_data)
	Submit an I2C write-then-read transaction asynchronously.

Detailed Description

I2C bus master driver.

Provides a portable I2C master API with configurable bus speed, thread-safe bus locking, register-level convenience functions, and device probing.

Two allocation strategies are supported:

_create() / _destroy() — heap-allocated. Available only when OVE_HEAP_I2C is defined (i.e. CONFIG_OVE_ZERO_HEAP is not set).
_init() / _deinit() — caller-supplied storage. Available in both modes. See OVE_I2C_DEFINE_STATIC for a one-step static helper.

All addresses are 7-bit (e.g. 0x50 for a typical EEPROM). The HAL shifts left and adds the R/W bit internally.

Note: Requires CONFIG_OVE_I2C. When the option is disabled every function is replaced by a no-op stub that returns OVE_ERR_NOT_SUPPORTED.

Macro Definition Documentation

◆ OVE_I2C_REG_WRITE_MAX

#define OVE_I2C_REG_WRITE_MAX 32

Maximum data bytes per ove_i2c_reg_write() call.

Enumeration Type Documentation

◆ ove_i2c_speed_t

enum ove_i2c_speed_t

I2C bus speed grade.

Enumerator
OVE_I2C_SPEED_STANDARD	100 kHz.
OVE_I2C_SPEED_FAST	400 kHz.
OVE_I2C_SPEED_FAST_PLUS	1 MHz.

Function Documentation

◆ ove_i2c_init()

int ove_i2c_init	(	ove_i2c_t *	i2c,
		ove_i2c_storage_t *	storage,
		const struct ove_i2c_cfg *	cfg
	)

Initialise an I2C bus using caller-provided static storage.

Parameters

[out]	i2c	Receives the initialised I2C handle.
[in]	storage	Pointer to statically-allocated I2C storage.
[in]	cfg	Bus configuration descriptor.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_deinit()

void ove_i2c_deinit ( ove_i2c_t i2c )

Deinitialise a statically-allocated I2C bus.

Parameters

[in] i2c I2C handle returned by ove_i2c_init.

◆ ove_i2c_create()

int ove_i2c_create	(	ove_i2c_t *	i2c,
		const struct ove_i2c_cfg *	cfg
	)

Create a heap-allocated I2C bus controller.

Parameters

[out]	i2c	Receives the created I2C handle.
[in]	cfg	Bus configuration descriptor.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_destroy()

void ove_i2c_destroy ( ove_i2c_t i2c )

Destroy a heap-allocated I2C bus controller.

Parameters

[in] i2c I2C handle returned by ove_i2c_create.

◆ ove_i2c_write()

int ove_i2c_write	(	ove_i2c_t	i2c,
		uint16_t	addr,
		const void *	data,
		size_t	len,
		uint64_t	timeout_ns
	)

Write data to an I2C device.

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[in]	data	Data to write.
[in]	len	Number of bytes to write.
[in]	timeout_ns	Maximum wait time; `OVE_WAIT_FOREVER` to block.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_read()

int ove_i2c_read	(	ove_i2c_t	i2c,
		uint16_t	addr,
		void *	buf,
		size_t	len,
		uint64_t	timeout_ns
	)

Read data from an I2C device.

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[out]	buf	Buffer to receive data.
[in]	len	Number of bytes to read.
[in]	timeout_ns	Maximum wait time; `OVE_WAIT_FOREVER` to block.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_write_read()

int ove_i2c_write_read	(	ove_i2c_t	i2c,
		uint16_t	addr,
		const void *	tx,
		size_t	tx_len,
		void *	rx,
		size_t	rx_len,
		uint64_t	timeout_ns
	)

Combined write-then-read with I2C repeated start.

Writes tx_len bytes from tx, then reads rx_len bytes into rx without releasing the bus (repeated start condition). This is the standard pattern for register reads on I2C sensors and codecs.

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[in]	tx	Transmit buffer (e.g. register address).
[in]	tx_len	Number of bytes to write.
[out]	rx	Receive buffer.
[in]	rx_len	Number of bytes to read.
[in]	timeout_ns	Maximum wait time; `OVE_WAIT_FOREVER` to block.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_reg_write()

int ove_i2c_reg_write	(	ove_i2c_t	i2c,
		uint16_t	addr,
		uint8_t	reg,
		const void *	data,
		size_t	len,
		uint64_t	timeout_ns
	)

Write to a single-byte-addressed register.

Prepends reg to data and performs a single I2C write. Implemented in the portable layer — not a HAL function.

Note: len must not exceed OVE_I2C_REG_WRITE_MAX (32 bytes).

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[in]	reg	Register address byte.
[in]	data	Data to write after the register byte.
[in]	len	Number of data bytes (max OVE_I2C_REG_WRITE_MAX).
[in]	timeout_ns	Maximum wait time.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_reg_read()

int ove_i2c_reg_read	(	ove_i2c_t	i2c,
		uint16_t	addr,
		uint8_t	reg,
		void *	buf,
		size_t	len,
		uint64_t	timeout_ns
	)

Read from a single-byte-addressed register.

Writes reg, then reads len bytes via repeated start. Implemented in the portable layer — not a HAL function.

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[in]	reg	Register address byte.
[out]	buf	Buffer to receive register data.
[in]	len	Number of bytes to read.
[in]	timeout_ns	Maximum wait time.

Returns: OVE_OK on success, negative error code on failure.

◆ ove_i2c_probe()

int ove_i2c_probe	(	ove_i2c_t	i2c,
		uint16_t	addr,
		uint64_t	timeout_ns
	)

Probe for a device at the given address.

Sends a zero-length write and checks for ACK. Useful for device enumeration and presence detection.

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address to probe.
[in]	timeout_ns	Maximum wait time.

Returns: OVE_OK if the device ACKs, OVE_ERR_BUS_NACK if not, other negative error code on bus failure.

◆ ove_i2c_write_read_async()

int ove_i2c_write_read_async	(	ove_i2c_t	i2c,
		uint16_t	addr,
		const void *	tx,
		size_t	tx_len,
		void *	rx,
		size_t	rx_len,
		ove_dma_complete_cb	cb,
		void *	user_data
	)

Submit an I2C write-then-read transaction asynchronously.

Equivalent to ove_i2c_write_read but returns immediately. The completion callback fires when the device has been written, the repeated-start completed, and the read finished — or when an error (NACK, bus error, timeout) terminates the transaction.

Same backend completion-context contract as ove_spi_transfer_async (ISR on STM32 + FreeRTOS DMA, thread on Zephyr signal / NuttX-POSIX worker fallback).

Parameters

[in]	i2c	I2C handle.
[in]	addr	7-bit device address.
[in]	tx	Bytes to write before the repeated start. Must outlive the transaction. May be NULL if `tx_len` is 0 (pure read).
[in]	tx_len	Number of bytes to write.
[in]	rx	Buffer for read bytes. Must outlive the transaction. May be NULL if `rx_len` is 0 (pure write).
[in]	rx_len	Number of bytes to read.
[in]	cb	Completion callback. Must not be NULL.
[in]	user_data	Opaque pointer forwarded to `cb`.

Returns: OVE_OK if accepted; negative on submission failure (no callback in that case).

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ OVE_I2C_REG_WRITE_MAX

Enumeration Type Documentation

◆ ove_i2c_speed_t

Function Documentation

◆ ove_i2c_init()

◆ ove_i2c_deinit()

◆ ove_i2c_create()

◆ ove_i2c_destroy()

◆ ove_i2c_write()

◆ ove_i2c_read()

◆ ove_i2c_write_read()

◆ ove_i2c_reg_write()

◆ ove_i2c_reg_read()

◆ ove_i2c_probe()

◆ ove_i2c_write_read_async()