pw_i2c_linux

Oveview

Linux userspace implementation for pw_i2c. Main docs: https://pigweed.dev/pw_i2c_linux.

Classes
class	pw::i2c::LinuxInitiator

Functions
static Result< int >	pw::i2c::LinuxInitiator::OpenI2cBus (const char *bus_path)
	pw::i2c::LinuxInitiator::LinuxInitiator (int fd)
	pw::i2c::LinuxInitiator::LinuxInitiator (const LinuxInitiator &)=delete
LinuxInitiator &	pw::i2c::LinuxInitiator::operator= (const LinuxInitiator &)=delete
Status	pw::i2c::LinuxInitiator::DoTransferFor (span< const Message > messages, chrono::SystemClock::duration timeout) override

Function Documentation

DoTransferFor()

Status pw::i2c::LinuxInitiator::DoTransferFor ( span< const Message >  messages, chrono::SystemClock::duration  timeout  )

overrideprivatevirtual

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

• Asserts that device_address is a 7-bit address.
• messages 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.

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.

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.