andrewm@0: /*
andrewm@0:  * SimpleGPIO.cpp
andrewm@0:  *
andrewm@0:  * Modifications by Derek Molloy, School of Electronic Engineering, DCU
andrewm@0:  * www.derekmolloy.ie
andrewm@0:  * Almost entirely based on Software by RidgeRun:
andrewm@0:  *
andrewm@0:  * Copyright (c) 2011, RidgeRun
andrewm@0:  * All rights reserved.
andrewm@0:  *
andrewm@0:  * Redistribution and use in source and binary forms, with or without
andrewm@0:  * modification, are permitted provided that the following conditions are met:
andrewm@0:  * 1. Redistributions of source code must retain the above copyright
andrewm@0:  *    notice, this list of conditions and the following disclaimer.
andrewm@0:  * 2. Redistributions in binary form must reproduce the above copyright
andrewm@0:  *    notice, this list of conditions and the following disclaimer in the
andrewm@0:  *    documentation and/or other materials provided with the distribution.
andrewm@0:  * 3. All advertising materials mentioning features or use of this software
andrewm@0:  *    must display the following acknowledgement:
andrewm@0:  *    This product includes software developed by the RidgeRun.
andrewm@0:  * 4. Neither the name of the RidgeRun nor the
andrewm@0:  *    names of its contributors may be used to endorse or promote products
andrewm@0:  *    derived from this software without specific prior written permission.
andrewm@0:  *
andrewm@0:  * THIS SOFTWARE IS PROVIDED BY RIDGERUN ''AS IS'' AND ANY
andrewm@0:  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
andrewm@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
andrewm@0:  * DISCLAIMED. IN NO EVENT SHALL RIDGERUN BE LIABLE FOR ANY
andrewm@0:  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
andrewm@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
andrewm@0:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
andrewm@0:  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
andrewm@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
andrewm@0:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
andrewm@0:  */
andrewm@0: 
andrewm@0: #include "../include/GPIOcontrol.h"
andrewm@0: #include <stdio.h>
andrewm@0: #include <stdlib.h>
andrewm@0: #include <string.h>
andrewm@0: #include <errno.h>
andrewm@0: #include <unistd.h>
andrewm@0: #include <fcntl.h>
andrewm@0: #include <poll.h>
andrewm@0: 
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_setup
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_setup(unsigned int gpio, int out_flag)
andrewm@0: {
andrewm@0: 	/* Export the GPIO pins and set their direction */
andrewm@0: 	if(gpio_export(gpio)) {
andrewm@0: 		printf("Unable to export GPIO input pin\n");
andrewm@0: 		return -1;
andrewm@0: 	}
andrewm@0: 	if(gpio_set_dir(gpio, out_flag)) {
andrewm@0: 		printf("Unable to set GPIO input direction\n");
andrewm@0: 		return -1;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	return gpio_fd_open(gpio, O_RDWR);
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_export
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_export(unsigned int gpio)
andrewm@0: {
andrewm@0: 	int fd, len, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	fd = open(SYSFS_GPIO_DIR "/export", O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/export");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	len = snprintf(buf, sizeof(buf), "%d", gpio);
andrewm@0: 	if(write(fd, buf, len) < 0)
andrewm@0: 		result = -1;
andrewm@0: 	close(fd);
andrewm@0: 
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_unexport
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_unexport(unsigned int gpio)
andrewm@0: {
andrewm@0: 	int fd, len, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	fd = open(SYSFS_GPIO_DIR "/unexport", O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/export");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	len = snprintf(buf, sizeof(buf), "%d", gpio);
andrewm@0: 	if(write(fd, buf, len) < 0)
andrewm@0: 		result = -1;
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_set_dir
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_set_dir(unsigned int gpio, int out_flag)
andrewm@0: {
andrewm@0: 	int fd, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR  "/gpio%d/direction", gpio);
andrewm@0: 
andrewm@0: 	fd = open(buf, O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/direction");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	if (out_flag == OUTPUT_PIN) {
andrewm@0: 		if(write(fd, "out", 4) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 	else {
andrewm@0: 		if(write(fd, "in", 3) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_set_value
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_set_value(unsigned int gpio, int value)
andrewm@0: {
andrewm@0: 	int fd, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
andrewm@0: 
andrewm@0: 	fd = open(buf, O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/set-value");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	if (value==LOW) {
andrewm@0: 		if(write(fd, "0", 2) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 	else {
andrewm@0: 		if(write(fd, "1", 2) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_get_value
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_get_value(unsigned int gpio, unsigned int *value)
andrewm@0: {
andrewm@0: 	int fd, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 	char ch;
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
andrewm@0: 
andrewm@0: 	fd = open(buf, O_RDONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/get-value");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	if(read(fd, &ch, 1) <= 0) {
andrewm@0: 		result = -1;
andrewm@0: 	}
andrewm@0: 	else {
andrewm@0: 		if (ch != '0') {
andrewm@0: 		*value = 1;
andrewm@0: 		} else {
andrewm@0: 		*value = 0;
andrewm@0: 		}
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_set_edge
andrewm@0:  ****************************************************************/
andrewm@0: 
andrewm@0: int gpio_set_edge(unsigned int gpio, char *edge)
andrewm@0: {
andrewm@0: 	int fd, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/edge", gpio);
andrewm@0: 
andrewm@0: 	fd = open(buf, O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/set-edge");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	if(write(fd, edge, strlen(edge) + 1) < 0)
andrewm@0: 		result = -1;
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_fd_open
andrewm@0:  ****************************************************************/
andrewm@0: 
andrewm@0: int gpio_fd_open(unsigned int gpio, int writeFlag)
andrewm@0: {
andrewm@0: 	int fd;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
andrewm@0: 
andrewm@0: 	fd = open(buf, writeFlag | O_NONBLOCK );
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/fd_open");
andrewm@0: 	}
andrewm@0: 	return fd;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_fd_close
andrewm@0:  ****************************************************************/
andrewm@0: 
andrewm@0: int gpio_fd_close(int fd)
andrewm@0: {
andrewm@0: 	return close(fd);
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_read
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_read(int fd, unsigned int *value)
andrewm@0: {
andrewm@0: 	int result = 0;
andrewm@0: 	char ch;
andrewm@0: 
andrewm@0: 	if(read(fd, &ch, 1) <= 0) {
andrewm@0: 		result = -1;
andrewm@0: 	}
andrewm@0: 	else {
andrewm@0: 		if (ch != '0') {
andrewm@0: 		*value = 1;
andrewm@0: 		} else {
andrewm@0: 		*value = 0;
andrewm@0: 		}
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_write
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_write(int fd, int value)
andrewm@0: {
andrewm@0: 	int result = 0;
andrewm@0: 	//char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	if (value==LOW) {
andrewm@0: 		if(write(fd, "0", 2) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 	else {
andrewm@0: 		if(write(fd, "1", 2) < 0)
andrewm@0: 			result = -1;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: 
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * gpio_dismiss
andrewm@0:  ****************************************************************/
andrewm@0: int gpio_dismiss(int fd, unsigned int gpio)
andrewm@0: {
andrewm@0: 	close(fd);
andrewm@0: 	gpio_unexport(gpio);
andrewm@0: 	return 0;
andrewm@0: }
andrewm@0: 
andrewm@0: /****************************************************************
andrewm@0:  * led_set_trigger
andrewm@0:  ****************************************************************/
andrewm@0: int led_set_trigger(unsigned int lednum, const char *trigger)
andrewm@0: {
andrewm@0: 	// Set the trigger source for an onboard user LED
andrewm@0: 	int fd, result = 0;
andrewm@0: 	char buf[MAX_BUF];
andrewm@0: 
andrewm@0: 	snprintf(buf, sizeof(buf), SYSFS_LED_DIR "/beaglebone:green:usr%d/trigger", lednum);
andrewm@0: 
andrewm@0: 	fd = open(buf, O_WRONLY);
andrewm@0: 	if (fd < 0) {
andrewm@0: 		perror("gpio/led-set-trigger");
andrewm@0: 		return fd;
andrewm@0: 	}
andrewm@0: 
andrewm@0: 	if(write(fd, trigger, strlen(trigger) + 1) < 0)
andrewm@0: 		result = -1;
andrewm@0: 
andrewm@0: 	close(fd);
andrewm@0: 	return result;
andrewm@0: }
andrewm@0: