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gpio-sysfs.h
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gpio-sysfs.h
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#ifndef __GPIOSYSFS
#define __GPIOSYSFS
/* Copyright (c) 2011, RidgeRun
* Copyright (c) 2014-2022, Bernd Porr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the RidgeRun and Bernd Porr.
* 4. Neither the name of the RidgeRun 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 RIDGERUN AND BERND PORR ''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 RIDGERUN OR BERND PORR 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
/****************************************************************
* Constants
****************************************************************/
#define SYSFS_GPIO_DIR "/sys/class/gpio"
#define MAX_BUF 256
class SysGPIO {
public:
SysGPIO(unsigned int gpioNumber) {
gpio = gpioNumber;
}
/**
* Starts accesss to the GPIO port
* \returns error code or zero on success
**/
int gpio_export();
/**
* Stops access to the GPIO port
* \returns error code or zero on success
**/
int gpio_unexport();
/**
* Sets direction
* \param out_flag is true for output
* \returns error code or zero on success
**/
int gpio_set_dir(bool out_flag);
/**
* Sets the value of a port. Can be one or Zero.
* \returns error code or zero on success
**/
int gpio_set_value(unsigned int value);
/**
* Gets the value of a port. Will be one or Zero.
* \param value is modified by the call to one or zero.
* \returns error code or zero on success
**/
int gpio_get_value(unsigned int &value);
/**
* Sets the change detection on the port.
* \param edge can be "rising" or "falling".
* \returns error code or zero on success
**/
int gpio_set_edge(const char *edge);
/**
* Gets a file descriptor on the "value" of the port.
* \returns The file descriptor
**/
int gpio_fd_open();
/**
* Puts the current thread to sleep until a change is detected
* on the file descriptor. Get the file descriptor
* by calling gpio_fd_open.
* \param gpio_fd file descriptor of value
* \param timeout Timeout in ms.
* \returns error code or one on success
**/
int gpio_poll(int gpio_fd, int timeout);
private:
int gpio;
};
#endif