#include <initiator.h>

Inheritance diagram for pw::i2c::LinuxInitiator:

Public Member Functions
	LinuxInitiator (int fd)

	LinuxInitiator (const LinuxInitiator &)=delete

LinuxInitiator &	operator= (const LinuxInitiator &)=delete

Public Member Functions inherited from pw::i2c::Initiator
constexpr	Initiator ()

constexpr	Initiator (Feature supported_features)

Status	WriteReadFor (Address device_address, ConstByteSpan tx_buffer, ByteSpan rx_buffer, chrono::SystemClock::duration timeout)

Status	TransferFor (span< const Message > messages, chrono::SystemClock::duration timeout)

Status	WriteReadFor (Address device_address, const void tx_buffer, size_t tx_size_bytes, void rx_buffer, size_t rx_size_bytes, chrono::SystemClock::duration timeout)

Status	WriteFor (Address device_address, ConstByteSpan tx_buffer, chrono::SystemClock::duration timeout)

Status	WriteFor (Address device_address, const void *tx_buffer, size_t tx_size_bytes, chrono::SystemClock::duration timeout)

Status	ReadFor (Address device_address, ByteSpan rx_buffer, chrono::SystemClock::duration timeout)

Status	ReadFor (Address device_address, void *rx_buffer, size_t rx_size_bytes, chrono::SystemClock::duration timeout)

Status	ProbeDeviceFor (Address device_address, chrono::SystemClock::duration timeout)

Static Public Member Functions
static Result< int >	OpenI2cBus (const char *bus_path)

Private Member Functions
Status	DoWriteReadFor (Address device_address, ConstByteSpan tx_buffer, ByteSpan rx_buffer, chrono::SystemClock::duration timeout) override

Additional Inherited Members
Public Types inherited from pw::i2c::Initiator
enum class	Feature : int { kStandard = 0 , kTenBit = (1 << 0) , kNoStart = (1 << 1) }
	Defined set of supported i2c features.

Detailed Description

Initiator interface implementation using the Linux userspace i2c-dev driver.

Takes exclusive control of an I2C bus device (ex. "/dev/i2c-0"). The user is responsible to open the device node prior to creating the initiator. The file descriptor is closed when the initiator object is destroyed.

The bus device must support the full I2C functionality. Users of the class are encouraged to use the OpenI2cBus helper to ensure the bus is valid.

Access to the bus is guarded by an internal mutex, so this initiator can be safely used from multiple threads.

Constructor & Destructor Documentation

◆ LinuxInitiator()

pw::i2c::LinuxInitiator::LinuxInitiator ( int fd )

Construct an instantiator using an open file descriptor. The file descriptor is closed during destruction.

Parameters

[in] fd Valid file descriptor for an I2C device node.

Member Function Documentation

◆ DoWriteReadFor()

Status pw::i2c::LinuxInitiator::DoWriteReadFor	(	Address	device_address,
		ConstByteSpan	tx_buffer,
		ByteSpan	rx_buffer,
		chrono::SystemClock::duration	timeout
	)

overrideprivatevirtual

Implement pw::i2c::Initiator with the following additional requriements:

Asserts that device_address is a 7-bit address.
At least one of tx_buffer or rx_buffer must be not empty. Otherwise, returns InvalidArgument.

Note: The timeout is used both for getting an exclusive lock on the initiator and for getting exclusive use of a multi-controller bus. If the timeout is zero or negative, the transaction will only execute if there is no contention at either level.

Reimplemented from pw::i2c::Initiator.

◆ OpenI2cBus()

static Result< int > pw::i2c::LinuxInitiator::OpenI2cBus ( const char * bus_path )

static

Open an I2C bus and validate that full I2C functionality is supported.

Parameters

[in] bus_path Path to the I2C bus device node.

Return values

OK	The device node was opened successfully.
InvalidArgument	Failed to open the device node or to validate I2C functionality.

Returns: The open file descriptor on success.

The documentation for this class was generated from the following file:

pw_i2c_linux/public/pw_i2c_linux/initiator.h

Public Member Functions

Static Public Member Functions