gpio.h File Reference

GPIO Helper Library API. More...

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Enumerations
enum	gpio_polarity { GPIO_POLARITY_INVALID, GPIO_POLARITY_ACTIVE_LOW, GPIO_POLARITY_ACTIVE_HIGH }
	GPIO Polarity types. More...
enum	gpio_edge {   GPIO_EDGE_INVALID, GPIO_EDGE_NONE, GPIO_EDGE_RISING, GPIO_EDGE_FALLING,   GPIO_EDGE_BOTH }
	GPIO Edge types. More...
enum	gpio_direction {   GPIO_DIRECTION_INVALID, GPIO_DIRECTION_IN, GPIO_DIRECTION_OUT, GPIO_DIRECTION_OUT_LOW,   GPIO_DIRECTION_OUT_HIGH }
	GPIO Direction types. More...

Functions
int	gpio_get_fd (void *gpio_handle, int *fdp)
	Get file descriptor associated with GPIO. More...
int	gpio_set_polarity (void *gpio_handle, enum gpio_polarity polarity)
	Set GPIO polarity. More...
int	gpio_set_edge (void *gpio_handle, enum gpio_edge edge)
	Set GPIO edge. More...
int	gpio_set_direction (void *gpio_handle, enum gpio_direction dir)
	Set GPIO direction. More...
int	gpio_read (void *gpio_handle, char *cp)
	Get value of GPIO. More...
int	gpio_write (void *gpio_handle, char c)
	Set value of GPIO. More...
int	gpio_init (char *gpio_num, void **gpio_handlep)
	Initialize a handle that provides access to specified GPIO. More...
int	gpio_destroy (void *gpio_handle)
	Destroy resource allocated by gpio_init() More...

Detailed Description

GPIO Helper Library API.

Author

Mark Greer mgree.nosp@m.r@an.nosp@m.imalc.nosp@m.reek.nosp@m..com

Set of routines to provide easy-to-use ways to perform common Linux(tm) GPIO operations.

Enumeration Type Documentation

enum gpio_direction

GPIO Direction types.

Types used to specify the GPIO direction.

Enumerator
GPIO_DIRECTION_INVALID	Invalid type (forces initialization)
GPIO_DIRECTION_IN	Input
GPIO_DIRECTION_OUT	Output (default)
GPIO_DIRECTION_OUT_LOW	Output with initial low value
GPIO_DIRECTION_OUT_HIGH	Output with initial high value

enum gpio_edge

GPIO Edge types.

Types used to specify the GPIO edge(s).

Enumerator
GPIO_EDGE_INVALID	Invalid type (forces initialization)
GPIO_EDGE_NONE	No edge
GPIO_EDGE_RISING	Rising edge
GPIO_EDGE_FALLING	Falling edge
GPIO_EDGE_BOTH	Rising and falling edge

enum gpio_polarity

GPIO Polarity types.

Types used to specify the GPIO polarity.

Enumerator
GPIO_POLARITY_INVALID	Invalid type (forces initialization)
GPIO_POLARITY_ACTIVE_LOW	Active low
GPIO_POLARITY_ACTIVE_HIGH	Active high

Function Documentation

int gpio_destroy

(

void *

gpio_handle

)

Destroy resource allocated by gpio_init()

Parameters

[in]

gpio_handle

Handle returned by gpio_init()

Returns

0 on success, negative errno on failure

int gpio_get_fd	(	void *	gpio_handle,
		int *	fdp
	)

Get file descriptor associated with GPIO.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[out]	fdp	Pointer to area where file descriptor is placed

Returns

0 on success, negative errno on failure

int gpio_init	(	char *	gpio_num,
		void **	gpio_handlep
	)

Initialize a handle that provides access to specified GPIO.

Parameters

[in]	gpio_num	Number of GPIO
[out]	gpio_handlep	Pointer to handle to use for GPIO operations

Returns

0 on success, negative errno on failure

int gpio_read	(	void *	gpio_handle,
		char *	cp
	)

Get value of GPIO.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[out]	cp	Pointer to where value is placed

Returns

0 on success, negative errno on failure

int gpio_set_direction	(	void *	gpio_handle,
		enum gpio_direction	dir
	)

Set GPIO direction.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[in]	dir	Direction to set GPIO to

Returns

0 on success, negative errno on failure

int gpio_set_edge	(	void *	gpio_handle,
		enum gpio_edge	edge
	)

Set GPIO edge.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[in]	edge	Edge to set GPIO to

Returns

0 on success, negative errno on failure

int gpio_set_polarity	(	void *	gpio_handle,
		enum gpio_polarity	polarity
	)

Set GPIO polarity.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[in]	polarity	Polarity to set GPIO to

Returns

0 on success, negative errno on failure

int gpio_write	(	void *	gpio_handle,
		char	c
	)

Set value of GPIO.

Parameters

[in]	gpio_handle	Handle returned by gpio_init()
[in]	c	Value to set GPIO to

Returns

0 on success, negative errno on failure