gpiod::line_request Class Reference

Stores the context of a set of requested GPIO lines. More...

#include <line-request.hpp>

Public Member Functions
	line_request (const line_request &other)=delete
	line_request (line_request &&other) noexcept
	Move constructor. More...
line_request &	operator= (const line_request &other)=delete
line_request &	operator= (line_request &&other) noexcept
	Move assignment operator. More...
	operator bool () const noexcept
	Check if this object is valid. More...
void	release ()
	Release the GPIO chip and free all associated resources. More...
::std::size_t	num_lines () const
	Get the number of requested lines. More...
line::offsets	offsets () const
	Get the list of offsets of requested lines. More...
line::value	get_value (line::offset offset)
	Get the value of a single requested line. More...
line::values	get_values (const line::offsets &offsets)
	Get the values of a subset of requested lines. More...
line::values	get_values ()
	Get the values of all requested lines. More...
void	get_values (const line::offsets &offsets, line::values &values)
	Get the values of a subset of requested lines into a vector supplied by the caller. More...
void	get_values (line::values &values)
	Get the values of all requested lines. More...
line_request &	set_value (line::offset offset, line::value value)
	Set the value of a single requested line. More...
line_request &	set_values (const line::value_mappings &values)
	Set the values of a subset of requested lines. More...
line_request &	set_values (const line::offsets &offsets, const line::values &values)
	Set the values of a subset of requested lines. More...
line_request &	set_values (const line::values &values)
	Set the values of all requested lines. More...
line_request &	reconfigure_lines (const line_config &config)
	Apply new config options to requested lines. More...
int	fd () const
	Get the file descriptor number associated with this line request. More...
bool	wait_edge_events (const ::std::chrono::nanoseconds &timeout) const
	Wait for edge events on any of the lines requested with edge detection enabled. More...
::std::size_t	read_edge_events (edge_event_buffer &buffer)
	Read a number of edge events from this request up to the maximum capacity of the buffer. More...
::std::size_t	read_edge_events (edge_event_buffer &buffer, ::std::size_t max_events)
	Read a number of edge events from this request. More...

Detailed Description

Stores the context of a set of requested GPIO lines.

Definition at line 37 of file line-request.hpp.

Constructor & Destructor Documentation

line_request()

gpiod::line_request::line_request ( line_request &&  other )

noexcept

Move constructor.

Parameters

other

Object to move.

Member Function Documentation

fd()

int gpiod::line_request::fd

(

)

const

Get the file descriptor number associated with this line request.

Returns

File descriptor number.

get_value()

line::value gpiod::line_request::get_value

(

line::offset

offset

)

Get the value of a single requested line.

Parameters

offset

Offset of the line to read within the chip.

Returns

Current line value.

get_values() [1/4]

line::values gpiod::line_request::get_values

(

)

Get the values of all requested lines.

Returns

List of read values.

get_values() [2/4]

line::values gpiod::line_request::get_values

(

const line::offsets &

offsets

)

Get the values of a subset of requested lines.

Parameters

offsets

Vector of line offsets

Returns

Vector of lines values with indexes of values corresponding to those of the offsets.

get_values() [3/4]

void gpiod::line_request::get_values	(	const line::offsets &	offsets,
		line::values &	values
	)

Get the values of a subset of requested lines into a vector supplied by the caller.

Parameters

offsets	Vector of line offsets.
values	Vector for storing the values. Its size must be at least that of the offsets vector. The indexes of read values will correspond with those in the offsets vector.

get_values() [4/4]

void gpiod::line_request::get_values

(

line::values &

values

)

Get the values of all requested lines.

Parameters

values

Array in which the values will be stored. Must hold at least the number of elements returned by line_request::num_lines.

num_lines()

::std::size_t gpiod::line_request::num_lines

(

)

const

Get the number of requested lines.

Returns

Number of lines in this request.

offsets()

line::offsets gpiod::line_request::offsets

(

)

const

Get the list of offsets of requested lines.

Returns

List of hardware offsets of the lines in this request.

operator bool()

gpiod::line_request::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 request was released. 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=()

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

noexcept

Move assignment operator.

Parameters

other

Object to move.

Returns

Reference to self.

read_edge_events() [1/2]

::std::size_t gpiod::line_request::read_edge_events

(

edge_event_buffer &

buffer

)

Read a number of edge events from this request up to the maximum capacity of the buffer.

Parameters

buffer

Edge event buffer to read events into.

Returns

Number of events read.

read_edge_events() [2/2]

::std::size_t gpiod::line_request::read_edge_events	(	edge_event_buffer &	buffer,
		::std::size_t	max_events
	)

Read a number of edge events from this request.

Parameters

buffer	Edge event buffer to read events into.
max_events	Maximum number of events to read. Limited by the capacity of the buffer.

Returns

Number of events read.

reconfigure_lines()

line_request& gpiod::line_request::reconfigure_lines

(

const line_config &

config

)

Apply new config options to requested lines.

Parameters

config

New configuration.

Returns

Reference to self.

release()

void gpiod::line_request::release

(

)

Release the GPIO chip and free all associated resources.

Note

The object can still be used after this method is called but using any of the mutators will result in throwing a logic_error exception.

set_value()

line_request& gpiod::line_request::set_value	(	line::offset	offset,
		line::value	value
	)

Set the value of a single requested line.

Parameters

offset	Offset of the line to set within the chip.
value	New line value.

Returns

Reference to self.

set_values() [1/3]

line_request& gpiod::line_request::set_values	(	const line::offsets &	offsets,
		const line::values &	values
	)

Set the values of a subset of requested lines.

Parameters

offsets	Vector containing the offsets of lines to set.
values	Vector containing new values with indexes corresponding with those in the offsets vector.

Returns

Reference to self.

set_values() [2/3]

line_request& gpiod::line_request::set_values

(

const line::value_mappings &

values

)

Set the values of a subset of requested lines.

Parameters

values

Vector containing a set of offset->value mappings.

Returns

Reference to self.

set_values() [3/3]

line_request& gpiod::line_request::set_values

(

const line::values &

values

)

Set the values of all requested lines.

Parameters

values

Array of new line values. The size must be equal to the value returned by line_request::num_lines.

Returns

Reference to self.

wait_edge_events()

bool gpiod::line_request::wait_edge_events

(

const ::std::chrono::nanoseconds &

timeout

)

const

Wait for edge events on any of the lines requested with edge detection enabled.

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.

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

• line-request.hpp