Represents a GPIO line and provides methods to interact with it. More...

#include <gpio2.h>

Collaboration diagram for Gpio2::Line:

Public Member Functions
	Line (std::shared_ptr< Chip > dev, uint32_t offset)
	Constructor for the Line class.

	Line (std::shared_ptr< Chip > dev, uint32_t num_lines, const uint32_t *offsets)
	Constructor for the Line class with multiple lines.

	Line (std::shared_ptr< Chip > dev, const LineRequest &request)
	Constructor for the Line class with a LineRequest object.

	~Line ()
	Destructor for the Line class. Closes the line if it is open.

	Line (const Line &)=delete

	Line (Line &&)=delete

Line &	operator= (const Line &)=delete

Line &	operator= (Line &&)=delete

int	errorCode () const
	Gets the last error code from the IOCTL operation.

int	result () const
	Gets the result of the last IOCTL operation.

const char *	errorMessage () const
	Gets the error message corresponding to the last error code.

const LineRequest &	request () const
	Gets the current line request configuration.

uint32_t	numLines () const
	Gets the number of lines in the request.

uint32_t	offset (uint32_t line_no=0) const
	Gets the offset of a specific line in the request.

const LineConfig &	config () const
	Gets the current line configuration.

bool	getInfo (LineInfo *info, uint32_t num_lines=1)
	Retrieves information about GPIO lines.

bool	open (uint64_t flags)
	Opens the GPIO line with the specified flags.

bool	open (const LineConfig &config)
	Opens the GPIO line with the specified configuration.

bool	setConfig (const LineConfig &config)
	Sets the configuration for the GPIO line.

bool	isOpen () const
	Checks if the GPIO line is open.

bool	close ()
	Closes the GPIO line.

bool	getValues (LineValues &values) const
	Gets the values of the GPIO line(s).

bool	getValue (int line_no=0) const
	Gets the value of a specific GPIO line.

bool	setValue (bool value, int line_no=0)
	Sets the value of a specific GPIO line.

bool	setValues (const LineValues &values)
	Sets the values of the GPIO line(s).

bool	setDebounce (uint32_t debounce_ms)
	Sets the debounce period for the GPIO line.

uint32_t	debounce () const
	Gets the debounce period for the GPIO line.

bool	waitForEvent (LineEvent &event, int timeout_ms=-1)
	Waits for an event on the GPIO line.

Private Attributes
std::shared_ptr< Chip >	m_chip

LineRequest	m_req

int	m_last_error

int	m_last_result

Detailed Description

Represents a GPIO line and provides methods to interact with it.

This class encapsulates the functionality to open, close, configure, and manipulate GPIO lines, as well as handle events.

Note: The class is not copyable or movable.

Definition at line 780 of file gpio2.h.

Constructor & Destructor Documentation

◆ Line() [1/5]

Gpio2::Line::Line	(	std::shared_ptr< Chip >	dev,
		uint32_t	offset
	)

inline

Constructor for the Line class.

Parameters

dev	A pointer to the associated Chip object.
offset	The offset of the GPIO line.

Definition at line 787 of file gpio2.h.

◆ Line() [2/5]

Gpio2::Line::Line	(	std::shared_ptr< Chip >	dev,
		uint32_t	num_lines,
		const uint32_t *	offsets
	)

inline

Constructor for the Line class with multiple lines.

Parameters

dev	A pointer to the associated Chip object.
num_lines	The number of lines.
offsets	A pointer to an array of line offsets.

Definition at line 795 of file gpio2.h.

References m_req.

◆ Line() [3/5]

Gpio2::Line::Line	(	std::shared_ptr< Chip >	dev,
		const LineRequest &	request
	)

inline

Constructor for the Line class with a LineRequest object.

Parameters

dev	A pointer to the associated Chip object.
request	A LineRequest object containing the line configuration.

Definition at line 807 of file gpio2.h.

References m_req.

◆ ~Line()

Gpio2::Line::~Line ( )

inline

Destructor for the Line class. Closes the line if it is open.

Definition at line 815 of file gpio2.h.

References close().

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◆ Line() [4/5]

Gpio2::Line::Line ( const Line & )

delete

◆ Line() [5/5]

Gpio2::Line::Line ( Line && )

delete

Member Function Documentation

◆ close()

bool Gpio2::Line::close ( )

inline

Closes the GPIO line.

Returns: true if the line was successfully closed, false otherwise.

Definition at line 1018 of file gpio2.h.

References close(), isOpen(), m_last_error, m_last_result, and m_req.

Referenced by close(), and ~Line().

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◆ config()

const LineConfig & Gpio2::Line::config ( ) const

inline

Gets the current line configuration.

Returns: A reference to the LineConfig object.

Definition at line 889 of file gpio2.h.

References m_req.

Referenced by open(), and setConfig().

◆ debounce()

uint32_t Gpio2::Line::debounce ( ) const

inline

Gets the debounce period for the GPIO line.

Returns: The debounce period in milliseconds.

Definition at line 1195 of file gpio2.h.

References m_req.

Referenced by setDebounce().

◆ errorCode()

int Gpio2::Line::errorCode ( ) const

inline

Gets the last error code from the IOCTL operation.

Returns: The error code.

Definition at line 829 of file gpio2.h.

References m_last_error.

Referenced by errorMessage().

◆ errorMessage()

const char * Gpio2::Line::errorMessage ( ) const

inline

Gets the error message corresponding to the last error code.

Returns: A string describing the error.

Definition at line 847 of file gpio2.h.

References errorCode().

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◆ getInfo()

bool Gpio2::Line::getInfo	(	LineInfo *	info,
		uint32_t	num_lines = `1`
	)

inline

Retrieves information about GPIO lines.

This function fetches information about a specified number of GPIO lines and stores it in the provided LineInfo array. The number of lines to retrieve is limited by the number of lines available in the request.

Parameters

[in]	info	Pointer to an array of `LineInfo` structures where the line information will be stored.
	num_lines	The number of lines to retrieve information for. Defaults to 1. If `num_lines` exceeds the number of lines available in the request, it will be clamped to the maximum available.

Returns: true if the information for all requested lines was successfully retrieved, false otherwise.

Definition at line 909 of file gpio2.h.

References m_chip, m_last_error, m_last_result, and m_req.

◆ getValue()

bool Gpio2::Line::getValue ( int line_no = 0 ) const

inline

Gets the value of a specific GPIO line.

The value returned are logical, indicating if the line is active or inactive. The #GPIO_V2_LINE_FLAG_ACTIVE_LOW flag controls the mapping between physical value (high/low) and logical value (active/inactive). If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is not set then high is active and low is inactive. If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is set then low is active and high is inactive.

If failed to get the value, an std::system_error exception is thrown.

Note: The values of both input and output lines may be read. For output lines, the value returned is driver and configuration dependent and may be either the output buffer (the last requested value set) or the input buffer (the actual level of the line), and depending on the hardware and configuration these may differ.

Parameters

line_no The line number (default is 0).

Returns: The value of the line (true for high, false for low).

Definition at line 1088 of file gpio2.h.

References getValues(), and isOpen().

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◆ getValues()

bool Gpio2::Line::getValues ( LineValues & values ) const

inline

Gets the values of the GPIO line(s).

The values returned are logical, indicating if the line is active or inactive. The #GPIO_V2_LINE_FLAG_ACTIVE_LOW flag controls the mapping between physical values (high/low) and logical values (active/inactive). If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is not set then high is active and low is inactive. If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is set then low is active and high is inactive.

Note: The values of both input and output lines may be read. For output lines, the value returned is driver and configuration dependent and may be either the output buffer (the last requested value set) or the input buffer (the actual level of the line), and depending on the hardware and configuration these may differ.

Parameters

values A reference to a LineValues object to be filled with line values.

Returns: true if the values were successfully retrieved, false otherwise.

Definition at line 1052 of file gpio2.h.

References isOpen(), m_last_error, m_last_result, and m_req.

Referenced by getValue().

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◆ isOpen()

bool Gpio2::Line::isOpen ( ) const

inline

Checks if the GPIO line is open.

Returns: true if the line is open, false otherwise.

Definition at line 1009 of file gpio2.h.

References m_req.

Referenced by close(), getValue(), getValues(), open(), open(), setConfig(), setValue(), setValues(), and waitForEvent().

◆ numLines()

uint32_t Gpio2::Line::numLines ( ) const

inline

Gets the number of lines in the request.

Returns: The number of lines in the request.

Definition at line 865 of file gpio2.h.

References m_req.

◆ offset()

uint32_t Gpio2::Line::offset ( uint32_t line_no = 0 ) const

inline

Gets the offset of a specific line in the request.

Parameters

line_no The line number (default is 0).

Returns: The offset of the specified line.

Exceptions

std::out_of_range if the line number is out of range.

Definition at line 876 of file gpio2.h.

References m_req.

◆ open() [1/2]

bool Gpio2::Line::open ( const LineConfig & config )

inline

Opens the GPIO line with the specified configuration.

Parameters

config The configuration for the line.

Returns: true if the line was successfully opened, false otherwise.

Definition at line 961 of file gpio2.h.

References config(), isOpen(), m_chip, m_last_error, m_last_result, and m_req.

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◆ open() [2/2]

bool Gpio2::Line::open ( uint64_t flags )

inline

Opens the GPIO line with the specified flags.

Parameters

flags The flags for opening the line.

Returns: true if the line was successfully opened, false otherwise.

Definition at line 937 of file gpio2.h.

References isOpen(), m_chip, m_last_error, m_last_result, and m_req.

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◆ operator=() [1/2]

Line & Gpio2::Line::operator= ( const Line & )

delete

◆ operator=() [2/2]

Line & Gpio2::Line::operator= ( Line && )

delete

◆ request()

const LineRequest & Gpio2::Line::request ( ) const

inline

Gets the current line request configuration.

Returns: A reference to the LineRequest object.

Definition at line 856 of file gpio2.h.

References m_req.

◆ result()

int Gpio2::Line::result ( ) const

inline

Gets the result of the last IOCTL operation.

Returns: The result of the operation.

Definition at line 838 of file gpio2.h.

References m_last_result.

◆ setConfig()

bool Gpio2::Line::setConfig ( const LineConfig & config )

inline

Sets the configuration for the GPIO line.

Parameters

config The new configuration for the line.

Returns: true if the configuration was successfully set, false otherwise.

Definition at line 985 of file gpio2.h.

References config(), isOpen(), m_last_error, m_last_result, and m_req.

Referenced by setDebounce().

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◆ setDebounce()

bool Gpio2::Line::setDebounce ( uint32_t debounce_ms )

inline

Sets the debounce period for the GPIO line.

Parameters

debounce_ms The debounce period in milliseconds.

Returns: true if the debounce period was successfully set or unchanged, false otherwise.

Definition at line 1165 of file gpio2.h.

References debounce(), m_req, and setConfig().

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◆ setValue()

bool Gpio2::Line::setValue	(	bool	value,
		int	line_no = `0`
	)

inline

Sets the value of a specific GPIO line.

The value set are logical, indicating if the line is to be active or inactive. The #GPIO_V2_LINE_FLAG_ACTIVE_LOW flag controls the mapping between logical values (active/inactive) and physical values (high/low). If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is not set then active is high and inactive is low. If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is set then active is low and inactive is high.

Only the values of output lines may be set. Attempting to set the value of an input line is an error (EPERM).

Parameters

line_no	The line number.
value	The value to set (true for high, false for low).

Returns: true if the value was successfully set, false otherwise.

Definition at line 1118 of file gpio2.h.

References isOpen(), and setValues().

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◆ setValues()

bool Gpio2::Line::setValues ( const LineValues & values )

inline

Sets the values of the GPIO line(s).

The values set are logical, indicating if the line is to be active or inactive. The #GPIO_V2_LINE_FLAG_ACTIVE_LOW flag controls the mapping between logical values (active/inactive) and physical values (high/low). If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is not set then active is high and inactive is low. If #GPIO_V2_LINE_FLAG_ACTIVE_LOW is set then active is low and inactive is high.

Only the values of output lines may be set. Attempting to set the value of an input line is an error (EPERM).

Parameters

values A reference to a LineValues object containing the values to set.

Returns: true if the values were successfully set, false otherwise.

Definition at line 1142 of file gpio2.h.

References isOpen(), m_last_error, m_last_result, and m_req.

Referenced by setValue().

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◆ waitForEvent()

bool Gpio2::Line::waitForEvent	(	LineEvent &	event,
		int	timeout_ms = `-1`
	)

inline

Waits for an event on the GPIO line.

Parameters

event	A reference to a LineEvent object to be filled with event data.
timeout_ms	The timeout in milliseconds. A negative value indicates no timeout.

Returns: true if an event was successfully received, false otherwise.

Definition at line 1207 of file gpio2.h.

References isOpen(), m_last_error, m_last_result, and m_req.

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Member Data Documentation

◆ m_chip

std::shared_ptr<Chip> Gpio2::Line::m_chip

private

Definition at line 1231 of file gpio2.h.

Referenced by getInfo(), open(), and open().

◆ m_last_error

int Gpio2::Line::m_last_error

mutableprivate

Definition at line 1233 of file gpio2.h.

Referenced by close(), errorCode(), getInfo(), getValues(), open(), open(), setConfig(), setValues(), and waitForEvent().

◆ m_last_result

int Gpio2::Line::m_last_result

mutableprivate

Definition at line 1234 of file gpio2.h.

Referenced by close(), getInfo(), getValues(), open(), open(), result(), setConfig(), setValues(), and waitForEvent().

◆ m_req

LineRequest Gpio2::Line::m_req

private

Definition at line 1232 of file gpio2.h.

Referenced by close(), config(), debounce(), getInfo(), getValues(), isOpen(), Line(), Line(), numLines(), offset(), open(), open(), request(), setConfig(), setDebounce(), setValues(), and waitForEvent().

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Line() [1/5]

◆ Line() [2/5]

◆ Line() [3/5]

◆ ~Line()

◆ Line() [4/5]

◆ Line() [5/5]

Member Function Documentation

◆ close()

◆ config()

◆ debounce()

◆ errorCode()

◆ errorMessage()

◆ getInfo()

◆ getValue()

◆ getValues()

◆ isOpen()

◆ numLines()

◆ offset()

◆ open() [1/2]

◆ open() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ request()

◆ result()

◆ setConfig()

◆ setDebounce()

◆ setValue()

◆ setValues()

◆ waitForEvent()

Member Data Documentation

◆ m_chip

◆ m_last_error

◆ m_last_result

◆ m_req