#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "sysfs.h"

Include dependency graph for sysfs.c:

Macros
#define	SYSFS_STRING_BUFFER_LENGTH 16
	String buffer size for dynamic string operations. More...

Functions
int	sysfs_export (char const *const sysfs_file, int value)

int	sysfs_unexport (char const *const sysfs_file, int value)

int	sysfs_is_exported (char const *const sysfs_path)

int	sysfs_export_unexported (char const const sysfs_path, char const const sysfs_export_file, int value)

int	sysfs_unexport_exported (char const const sysfs_path, char const const sysfs_unexport_file, int value)

int	sysfs_write_string (char const const sysfs_file, char const const value)

int	sysfs_read_string (char const const sysfs_file, char const value, int length)

int	sysfs_write_int (char const *const sysfs_file, int value)

int	sysfs_read_int (char const const sysfs_file, int const value)

Macro Definition Documentation

◆ SYSFS_STRING_BUFFER_LENGTH

#define SYSFS_STRING_BUFFER_LENGTH 16

String buffer size for dynamic string operations.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Definition at line 45 of file sysfs.c.

Function Documentation

◆ sysfs_export()

int sysfs_export	(	char const *const	sysfs_file,
		int	value
	)

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Export (activate) a sysfs device.

If the ressource is busy an error is returned. You might want to use sysfs_unexport first to make sure a device is deactivated.

Parameters

sysfs_file	The sysfs file used to export
value	The resource number of the device to export

Returns: 0 in case of success, -1 otherwise

Definition at line 50 of file sysfs.c.

References sysfs_write_int().

Referenced by sysfs_export_unexported().

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◆ sysfs_export_unexported()

int sysfs_export_unexported	(	char const *const	sysfs_path,
		char const *const	sysfs_export_file,
		int	value
	)

Export (activate) a sysfs device if it is not exported already.

Returns success immediately if the sysfs device is exported already, otherwise calls and returns sysfs_export result.

Parameters

sysfs_path	The sysfs device path to check
sysfs_export_file	The sysfs file to use to export
value	The resource number of the device to export

Returns: 0 if device successfully exported, 1 if device was exported already, -1 on failure

Definition at line 76 of file sysfs.c.

References sysfs_export(), and sysfs_is_exported().

Referenced by pwm_init().

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◆ sysfs_is_exported()

int sysfs_is_exported ( char const *const sysfs_path )

Check wether a sysfs device is exported and fully accessible.

Parameters

sysfs_path The sysfs device path to check

Returns: 1 if device is exported, 0 if device is not exported, -1 on failure

Definition at line 58 of file sysfs.c.

Referenced by sysfs_export_unexported(), and sysfs_unexport_exported().

◆ sysfs_read_int()

int sysfs_read_int	(	char const *const	sysfs_file,
		int *const	value
	)

Write an integer to a sysfs device file.

Parameters

sysfs_file	The sysfs file to read from
value	Pointer to the integer variable to write to

Returns: 0 in case of success, -1 otherwise

Definition at line 145 of file sysfs.c.

References sysfs_read_string().

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◆ sysfs_read_string()

int sysfs_read_string	(	char const *const	sysfs_file,
		char *const	value,
		int	length
	)

Read a string from a sysfs device file.

Parameters

sysfs_file	The sysfs file to read from
value	Pointer to the character array to write to
length	Max length to the string to read

Returns: Read string length in case of success, -1 on failure

Definition at line 121 of file sysfs.c.

Referenced by sysfs_read_int().

◆ sysfs_unexport()

int sysfs_unexport	(	char const *const	sysfs_file,
		int	value
	)

Unexport (deactivate) a sysfs device.

Parameters

sysfs_file	The sysfs file used to unexport
value	The resource number of the device to unexport

Returns: 0 in case of success, -1 otherwise.

Definition at line 54 of file sysfs.c.

References sysfs_write_int().

Referenced by pwm_deinit(), and sysfs_unexport_exported().

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◆ sysfs_unexport_exported()

int sysfs_unexport_exported	(	char const *const	sysfs_path,
		char const *const	sysfs_unexport_file,
		int	value
	)

Unexport (deactivate) a sysfs device if it is exported (active).

Returns success immediately if the sysfs device is not exported, otherwise calls and returns sysfs_unexport result.

Parameters

sysfs_path	The sysfs device path to check
sysfs_unexport_file	The sysfs file to use to unexport
value	The resource number of the device to unexport

Returns: 0 if device successfully unexported, 1 if device was not exported, -1 on failure

Definition at line 91 of file sysfs.c.

References sysfs_is_exported(), and sysfs_unexport().

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◆ sysfs_write_int()

int sysfs_write_int	(	char const *const	sysfs_file,
		int	value
	)

Write an integer to a sysfs device file.

Parameters

sysfs_file	The sysfs file to write to
value	The value to write to write

Returns: 0 in case of success, -1 otherwise

Definition at line 136 of file sysfs.c.

Referenced by pwm_deinit(), pwm_init(), sysfs_export(), and sysfs_unexport().

◆ sysfs_write_string()

int sysfs_write_string	(	char const *const	sysfs_file,
		char const *const	value
	)

Write a string to a sysfs device file.

Parameters

sysfs_file	The sysfs file to write to
value	The value to write to write

Returns: 0 in case of success, -1 otherwise

Definition at line 106 of file sysfs.c.

Macros

Functions

Macro Definition Documentation

◆ SYSFS_STRING_BUFFER_LENGTH

Function Documentation

◆ sysfs_export()

◆ sysfs_export_unexported()

◆ sysfs_is_exported()

◆ sysfs_read_int()

◆ sysfs_read_string()

◆ sysfs_unexport()

◆ sysfs_unexport_exported()

◆ sysfs_write_int()

◆ sysfs_write_string()