Interface for requesting GPIO lines from userspace for both values and events. More...

Collaboration diagram for Line requests:

Data Structures
struct	gpiod_line_request_config
	Structure holding configuration of a line request. More...

Enumerations
enum	{ GPIOD_LINE_REQUEST_DIRECTION_AS_IS = 1, GPIOD_LINE_REQUEST_DIRECTION_INPUT, GPIOD_LINE_REQUEST_DIRECTION_OUTPUT, GPIOD_LINE_REQUEST_EVENT_FALLING_EDGE, GPIOD_LINE_REQUEST_EVENT_RISING_EDGE, GPIOD_LINE_REQUEST_EVENT_BOTH_EDGES }
	Available types of requests. More...

enum	{ GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN = GPIOD_BIT(0), GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE = GPIOD_BIT(1), GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW = GPIOD_BIT(2), GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE = GPIOD_BIT(3), GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN = GPIOD_BIT(4), GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP = GPIOD_BIT(5) }
	Miscellaneous GPIO request flags. More...

Functions
int	gpiod_line_request (struct gpiod_line line, const struct gpiod_line_request_config config, int default_val) GPIOD_API
	Reserve a single line. More...

int	gpiod_line_request_input (struct gpiod_line line, const char consumer) GPIOD_API
	Reserve a single line, set the direction to input. More...

int	gpiod_line_request_output (struct gpiod_line line, const char consumer, int default_val) GPIOD_API
	Reserve a single line, set the direction to output. More...

int	gpiod_line_request_rising_edge_events (struct gpiod_line line, const char consumer) GPIOD_API
	Request rising edge event notifications on a single line. More...

int	gpiod_line_request_falling_edge_events (struct gpiod_line line, const char consumer) GPIOD_API
	Request falling edge event notifications on a single line. More...

int	gpiod_line_request_both_edges_events (struct gpiod_line line, const char consumer) GPIOD_API
	Request all event type notifications on a single line. More...

int	gpiod_line_request_input_flags (struct gpiod_line line, const char consumer, int flags) GPIOD_API
	Reserve a single line, set the direction to input. More...

int	gpiod_line_request_output_flags (struct gpiod_line line, const char consumer, int flags, int default_val) GPIOD_API
	Reserve a single line, set the direction to output. More...

int	gpiod_line_request_rising_edge_events_flags (struct gpiod_line line, const char consumer, int flags) GPIOD_API
	Request rising edge event notifications on a single line. More...

int	gpiod_line_request_falling_edge_events_flags (struct gpiod_line line, const char consumer, int flags) GPIOD_API
	Request falling edge event notifications on a single line. More...

int	gpiod_line_request_both_edges_events_flags (struct gpiod_line line, const char consumer, int flags) GPIOD_API
	Request all event type notifications on a single line. More...

int	gpiod_line_request_bulk (struct gpiod_line_bulk bulk, const struct gpiod_line_request_config config, const int *default_vals) GPIOD_API
	Reserve a set of GPIO lines. More...

int	gpiod_line_request_bulk_input (struct gpiod_line_bulk bulk, const char consumer) GPIOD_API
	Reserve a set of GPIO lines, set the direction to input. More...

int	gpiod_line_request_bulk_output (struct gpiod_line_bulk bulk, const char consumer, const int *default_vals) GPIOD_API
	Reserve a set of GPIO lines, set the direction to output. More...

int	gpiod_line_request_bulk_rising_edge_events (struct gpiod_line_bulk bulk, const char consumer) GPIOD_API
	Request rising edge event notifications on a set of lines. More...

int	gpiod_line_request_bulk_falling_edge_events (struct gpiod_line_bulk bulk, const char consumer) GPIOD_API
	Request falling edge event notifications on a set of lines. More...

int	gpiod_line_request_bulk_both_edges_events (struct gpiod_line_bulk bulk, const char consumer) GPIOD_API
	Request all event type notifications on a set of lines. More...

int	gpiod_line_request_bulk_input_flags (struct gpiod_line_bulk bulk, const char consumer, int flags) GPIOD_API
	Reserve a set of GPIO lines, set the direction to input. More...

int	gpiod_line_request_bulk_output_flags (struct gpiod_line_bulk bulk, const char consumer, int flags, const int *default_vals) GPIOD_API
	Reserve a set of GPIO lines, set the direction to output. More...

int	gpiod_line_request_bulk_rising_edge_events_flags (struct gpiod_line_bulk bulk, const char consumer, int flags) GPIOD_API
	Request rising edge event notifications on a set of lines. More...

int	gpiod_line_request_bulk_falling_edge_events_flags (struct gpiod_line_bulk bulk, const char consumer, int flags) GPIOD_API
	Request falling edge event notifications on a set of lines. More...

int	gpiod_line_request_bulk_both_edges_events_flags (struct gpiod_line_bulk bulk, const char consumer, int flags) GPIOD_API
	Request all event type notifications on a set of lines. More...

void	gpiod_line_release (struct gpiod_line *line) GPIOD_API
	Release a previously reserved line. More...

void	gpiod_line_release_bulk (struct gpiod_line_bulk *bulk) GPIOD_API
	Release a set of previously reserved lines. More...

bool	gpiod_line_is_requested (struct gpiod_line *line) GPIOD_API
	Check if the calling user has ownership of this line. More...

bool	gpiod_line_is_free (struct gpiod_line *line) GPIOD_API
	Check if the calling user has neither requested ownership of this line nor configured any event notifications. More...

Detailed Description

Interface for requesting GPIO lines from userspace for both values and events.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Available types of requests.

Enumerator
GPIOD_LINE_REQUEST_DIRECTION_AS_IS	Request the line(s), but don't change current direction.
GPIOD_LINE_REQUEST_DIRECTION_INPUT	Request the line(s) for reading the GPIO line state.
GPIOD_LINE_REQUEST_DIRECTION_OUTPUT	Request the line(s) for setting the GPIO line state.
GPIOD_LINE_REQUEST_EVENT_FALLING_EDGE	Only watch falling edge events.
GPIOD_LINE_REQUEST_EVENT_RISING_EDGE	Only watch rising edge events.
GPIOD_LINE_REQUEST_EVENT_BOTH_EDGES	Monitor both types of events.

Definition at line 972 of file gpiod.h.

◆ anonymous enum

anonymous enum

Miscellaneous GPIO request flags.

Enumerator
GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN	The line is an open-drain port.
GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE	The line is an open-source port.
GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW	The active state of the line is low (high is the default).
GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE	The line has neither either pull-up nor pull-down resistor.
GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN	The line has pull-down resistor enabled.
GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP	The line has pull-up resistor enabled.

Definition at line 990 of file gpiod.h.

Function Documentation

◆ gpiod_line_is_free()

bool gpiod_line_is_free ( struct gpiod_line * line )

Check if the calling user has neither requested ownership of this line nor configured any event notifications.

Parameters

line	GPIO line object.

Returns: True if given line is free, false otherwise.

◆ gpiod_line_is_requested()

bool gpiod_line_is_requested ( struct gpiod_line * line )

Check if the calling user has ownership of this line.

Parameters

line	GPIO line object.

Returns: True if given line was requested, false otherwise.

◆ gpiod_line_release()

void gpiod_line_release ( struct gpiod_line * line )

Release a previously reserved line.

Parameters

line	GPIO line object.

◆ gpiod_line_release_bulk()

void gpiod_line_release_bulk ( struct gpiod_line_bulk * bulk )

Release a set of previously reserved lines.

Parameters

bulk	Set of GPIO lines to release.

If the lines were not previously requested together, the behavior is undefined.

◆ gpiod_line_request()

int gpiod_line_request	(	struct gpiod_line *	line,
		const struct gpiod_line_request_config *	config,
		int	default_val
	)

Reserve a single line.

Parameters

line	GPIO line object.
config	Request options.
default_val	Initial line value - only relevant if we're setting the direction to output.

Returns: 0 if the line was properly reserved. In case of an error this routine returns -1 and sets the last error number.

If this routine succeeds, the caller takes ownership of the GPIO line until it's released.

◆ gpiod_line_request_both_edges_events()

int gpiod_line_request_both_edges_events	(	struct gpiod_line *	line,
		const char *	consumer
	)

Request all event type notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_both_edges_events_flags()

int gpiod_line_request_both_edges_events_flags	(	struct gpiod_line *	line,
		const char *	consumer,
		int	flags
	)

Request all event type notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk()

int gpiod_line_request_bulk	(	struct gpiod_line_bulk *	bulk,
		const struct gpiod_line_request_config *	config,
		const int *	default_vals
	)

Reserve a set of GPIO lines.

Parameters

bulk	Set of GPIO lines to reserve.
config	Request options.
default_vals	Initial line values - only relevant if we're setting the direction to output.

Returns: 0 if the all lines were properly requested. In case of an error this routine returns -1 and sets the last error number.

If this routine succeeds, the caller takes ownership of the GPIO lines until they're released. All the requested lines must be prodivided by the same gpiochip.

◆ gpiod_line_request_bulk_both_edges_events()

int gpiod_line_request_bulk_both_edges_events	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer
	)

Request all event type notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk_both_edges_events_flags()

int gpiod_line_request_bulk_both_edges_events_flags	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		int	flags
	)

Request all event type notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk_falling_edge_events()

int gpiod_line_request_bulk_falling_edge_events	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer
	)

Request falling edge event notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk_falling_edge_events_flags()

int gpiod_line_request_bulk_falling_edge_events_flags	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		int	flags
	)

Request falling edge event notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk_input()

int gpiod_line_request_bulk_input	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer
	)

Reserve a set of GPIO lines, set the direction to input.

Parameters

bulk	Set of GPIO lines to reserve.
consumer	Name of the consumer.

Returns: 0 if the lines were properly reserved, -1 on failure.

◆ gpiod_line_request_bulk_input_flags()

int gpiod_line_request_bulk_input_flags	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		int	flags
	)

Reserve a set of GPIO lines, set the direction to input.

Parameters

bulk	Set of GPIO lines to reserve.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the lines were properly reserved, -1 on failure.

◆ gpiod_line_request_bulk_output()

int gpiod_line_request_bulk_output	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		const int *	default_vals
	)

Reserve a set of GPIO lines, set the direction to output.

Parameters

bulk	Set of GPIO lines to reserve.
consumer	Name of the consumer.
default_vals	Initial line values.

Returns: 0 if the lines were properly reserved, -1 on failure.

◆ gpiod_line_request_bulk_output_flags()

int gpiod_line_request_bulk_output_flags	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		int	flags,
		const int *	default_vals
	)

Reserve a set of GPIO lines, set the direction to output.

Parameters

bulk	Set of GPIO lines to reserve.
consumer	Name of the consumer.
flags	Additional request flags.
default_vals	Initial line values.

Returns: 0 if the lines were properly reserved, -1 on failure.

◆ gpiod_line_request_bulk_rising_edge_events()

int gpiod_line_request_bulk_rising_edge_events	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer
	)

Request rising edge event notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_bulk_rising_edge_events_flags()

int gpiod_line_request_bulk_rising_edge_events_flags	(	struct gpiod_line_bulk *	bulk,
		const char *	consumer,
		int	flags
	)

Request rising edge event notifications on a set of lines.

Parameters

bulk	Set of GPIO lines to request.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_falling_edge_events()

int gpiod_line_request_falling_edge_events	(	struct gpiod_line *	line,
		const char *	consumer
	)

Request falling edge event notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_falling_edge_events_flags()

int gpiod_line_request_falling_edge_events_flags	(	struct gpiod_line *	line,
		const char *	consumer,
		int	flags
	)

Request falling edge event notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_input()

int gpiod_line_request_input	(	struct gpiod_line *	line,
		const char *	consumer
	)

Reserve a single line, set the direction to input.

Parameters

line	GPIO line object.
consumer	Name of the consumer.

Returns: 0 if the line was properly reserved, -1 on failure.

◆ gpiod_line_request_input_flags()

int gpiod_line_request_input_flags	(	struct gpiod_line *	line,
		const char *	consumer,
		int	flags
	)

Reserve a single line, set the direction to input.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the line was properly reserved, -1 on failure.

◆ gpiod_line_request_output()

int gpiod_line_request_output	(	struct gpiod_line *	line,
		const char *	consumer,
		int	default_val
	)

Reserve a single line, set the direction to output.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
default_val	Initial line value.

Returns: 0 if the line was properly reserved, -1 on failure.

◆ gpiod_line_request_output_flags()

int gpiod_line_request_output_flags	(	struct gpiod_line *	line,
		const char *	consumer,
		int	flags,
		int	default_val
	)

Reserve a single line, set the direction to output.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
flags	Additional request flags.
default_val	Initial line value.

Returns: 0 if the line was properly reserved, -1 on failure.

◆ gpiod_line_request_rising_edge_events()

int gpiod_line_request_rising_edge_events	(	struct gpiod_line *	line,
		const char *	consumer
	)

Request rising edge event notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.

Returns: 0 if the operation succeeds, -1 on failure.

◆ gpiod_line_request_rising_edge_events_flags()

int gpiod_line_request_rising_edge_events_flags	(	struct gpiod_line *	line,
		const char *	consumer,
		int	flags
	)

Request rising edge event notifications on a single line.

Parameters

line	GPIO line object.
consumer	Name of the consumer.
flags	Additional request flags.

Returns: 0 if the operation succeeds, -1 on failure.

Data Structures

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

◆ anonymous enum

◆ anonymous enum

Function Documentation

◆ gpiod_line_is_free()

◆ gpiod_line_is_requested()

◆ gpiod_line_release()

◆ gpiod_line_release_bulk()

◆ gpiod_line_request()

◆ gpiod_line_request_both_edges_events()

◆ gpiod_line_request_both_edges_events_flags()

◆ gpiod_line_request_bulk()

◆ gpiod_line_request_bulk_both_edges_events()

◆ gpiod_line_request_bulk_both_edges_events_flags()

◆ gpiod_line_request_bulk_falling_edge_events()

◆ gpiod_line_request_bulk_falling_edge_events_flags()

◆ gpiod_line_request_bulk_input()

◆ gpiod_line_request_bulk_input_flags()

◆ gpiod_line_request_bulk_output()

◆ gpiod_line_request_bulk_output_flags()

◆ gpiod_line_request_bulk_rising_edge_events()

◆ gpiod_line_request_bulk_rising_edge_events_flags()

◆ gpiod_line_request_falling_edge_events()

◆ gpiod_line_request_falling_edge_events_flags()

◆ gpiod_line_request_input()

◆ gpiod_line_request_input_flags()

◆ gpiod_line_request_output()

◆ gpiod_line_request_output_flags()

◆ gpiod_line_request_rising_edge_events()

◆ gpiod_line_request_rising_edge_events_flags()