gpiod::chip Class Reference

Represents a GPIO chip. More...

#include <chip.hpp>

Public Member Functions
	chip (const ::std::filesystem::path &path)
	Instantiates a new chip object by opening the device file indicated by the path argument. More...
	chip (chip &&other) noexcept
	Move constructor. More...
chip &	operator= (const chip &other)=delete
chip &	operator= (chip &&other) noexcept
	Move assignment operator. More...
	operator bool () const noexcept
	Check if this object is valid. More...
void	close ()
	Close the GPIO chip device file and free associated resources. More...
::std::filesystem::path	path () const
	Get the filesystem path that was used to open this GPIO chip. More...
chip_info	get_info () const
	Get information about the chip. More...
line_info	get_line_info (line::offset offset) const
	Retrieve the current snapshot of line information for a single line. More...
line_info	watch_line_info (line::offset offset) const
	Wrapper around gpiod::chip::get_line_info that retrieves the line info and starts watching the line for changes. More...
void	unwatch_line_info (line::offset offset) const
	Stop watching the line at given offset for info events. More...
int	fd () const
	Get the file descriptor associated with this chip. More...
bool	wait_info_event (const ::std::chrono::nanoseconds &timeout) const
	Wait for line status events on any of the watched lines exposed by this chip. More...
info_event	read_info_event () const
	Read a single line status change event from this chip. More...
int	get_line_offset_from_name (const ::std::string &name) const
	Map a GPIO line's name to its offset within the chip. More...
request_builder	prepare_request ()
	Create a request_builder associated with this chip. More...

Detailed Description

Represents a GPIO chip.

Definition at line 41 of file chip.hpp.

Constructor & Destructor Documentation

chip() [1/2]

gpiod::chip::chip ( const ::std::filesystem::path &  path )

explicit

Instantiates a new chip object by opening the device file indicated by the path argument.

Parameters

path	Path to the device file to open.

chip() [2/2]

gpiod::chip::chip ( chip &&  other )

noexcept

Move constructor.

Parameters

other

Object to move.

Member Function Documentation

close()

void gpiod::chip::close

(

)

Close the GPIO chip device file and free associated resources.

Note

The chip object can live after calling this method but any of the chip's mutators will throw a logic_error exception.

fd()

int gpiod::chip::fd

(

)

const

Get the file descriptor associated with this chip.

Returns

File descriptor number.

get_info()

chip_info gpiod::chip::get_info

(

)

const

Get information about the chip.

Returns

New chip_info object.

get_line_info()

line_info gpiod::chip::get_line_info

(

line::offset

offset

)

const

Retrieve the current snapshot of line information for a single line.

Parameters

offset

Offset of the line to get the info for.

Returns

New gpiod::line_info object.

get_line_offset_from_name()

int gpiod::chip::get_line_offset_from_name

(

const ::std::string &

name

)

const

Map a GPIO line's name to its offset within the chip.

Parameters

name	Name of the GPIO line to map.

Returns

Offset of the line within the chip or -1 if the line with given name is not exposed by this chip.

operator bool()

gpiod::chip::operator bool ( ) const

explicitnoexcept

Check if this object is valid.

Returns

True if this object's methods can be used, false otherwise. False usually means the chip was closed. If the user calls any of the methods of this class on an object for which this operator returned false, a logic_error will be thrown.

operator=()

chip& gpiod::chip::operator= ( chip &&  other )

noexcept

Move assignment operator.

Parameters

other

Object to move.

Returns

Reference to self.

path()

::std::filesystem::path gpiod::chip::path

(

)

const

Get the filesystem path that was used to open this GPIO chip.

Returns

Path to the underlying character device file.

prepare_request()

request_builder gpiod::chip::prepare_request

(

)

Create a request_builder associated with this chip.

Returns

New request_builder object.

read_info_event()

info_event gpiod::chip::read_info_event

(

)

const

Read a single line status change event from this chip.

Returns

New info_event object.

unwatch_line_info()

void gpiod::chip::unwatch_line_info

(

line::offset

offset

)

const

Stop watching the line at given offset for info events.

Parameters

offset

Offset of the line to get the info for.

wait_info_event()

bool gpiod::chip::wait_info_event

(

const ::std::chrono::nanoseconds &

timeout

)

const

Wait for line status events on any of the watched lines exposed by this chip.

Parameters

timeout

Wait time limit in nanoseconds.

Returns

True if at least one event is ready to be read. False if the wait timed out.

watch_line_info()

line_info gpiod::chip::watch_line_info

(

line::offset

offset

)

const

Wrapper around gpiod::chip::get_line_info that retrieves the line info and starts watching the line for changes.

Parameters

offset

Offset of the line to get the info for.

Returns

New gpiod::line_info object.

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

• chip.hpp