comparison core/GPIOcontrol.cpp @ 0:8a575ba3ab52

Initial commit.

+/*
+ * SimpleGPIO.cpp
+ *
+ * Modifications by Derek Molloy, School of Electronic Engineering, DCU
+ * www.derekmolloy.ie
+ * Almost entirely based on Software by RidgeRun:
+ *
+ * Copyright (c) 2011, RidgeRun
+ * 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.
+ * 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 ''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 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 "../include/GPIOcontrol.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <poll.h>
+
+
+/****************************************************************
+ * gpio_setup
+ ****************************************************************/
+int gpio_setup(unsigned int gpio, int out_flag)
+{
+	/* Export the GPIO pins and set their direction */
+	if(gpio_export(gpio)) {
+		printf("Unable to export GPIO input pin\n");
+		return -1;
+	}
+	if(gpio_set_dir(gpio, out_flag)) {
+		printf("Unable to set GPIO input direction\n");
+		return -1;
+	}
+
+	return gpio_fd_open(gpio, O_RDWR);
+}
+
+/****************************************************************
+ * gpio_export
+ ****************************************************************/
+int gpio_export(unsigned int gpio)
+{
+	int fd, len, result = 0;
+	char buf[MAX_BUF];
+
+	fd = open(SYSFS_GPIO_DIR "/export", O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/export");
+		return fd;
+	}
+
+	len = snprintf(buf, sizeof(buf), "%d", gpio);
+	if(write(fd, buf, len) < 0)
+		result = -1;
+	close(fd);
+
+	return result;
+}
+
+/****************************************************************
+ * gpio_unexport
+ ****************************************************************/
+int gpio_unexport(unsigned int gpio)
+{
+	int fd, len, result = 0;
+	char buf[MAX_BUF];
+
+	fd = open(SYSFS_GPIO_DIR "/unexport", O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/export");
+		return fd;
+	}
+
+	len = snprintf(buf, sizeof(buf), "%d", gpio);
+	if(write(fd, buf, len) < 0)
+		result = -1;
+	close(fd);
+	return result;
+}
+
+/****************************************************************
+ * gpio_set_dir
+ ****************************************************************/
+int gpio_set_dir(unsigned int gpio, int out_flag)
+{
+	int fd, result = 0;
+	char buf[MAX_BUF];
+
+	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR  "/gpio%d/direction", gpio);
+
+	fd = open(buf, O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/direction");
+		return fd;
+	}
+
+	if (out_flag == OUTPUT_PIN) {
+		if(write(fd, "out", 4) < 0)
+			result = -1;
+	}
+	else {
+		if(write(fd, "in", 3) < 0)
+			result = -1;
+	}
+
+	close(fd);
+	return result;
+}
+
+/****************************************************************
+ * gpio_set_value
+ ****************************************************************/
+int gpio_set_value(unsigned int gpio, int value)
+{
+	int fd, result = 0;
+	char buf[MAX_BUF];
+
+	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
+
+	fd = open(buf, O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/set-value");
+		return fd;
+	}
+
+	if (value==LOW) {
+		if(write(fd, "0", 2) < 0)
+			result = -1;
+	}
+	else {
+		if(write(fd, "1", 2) < 0)
+			result = -1;
+	}
+
+	close(fd);
+	return result;
+}
+
+/****************************************************************
+ * gpio_get_value
+ ****************************************************************/
+int gpio_get_value(unsigned int gpio, unsigned int *value)
+{
+	int fd, result = 0;
+	char buf[MAX_BUF];
+	char ch;
+
+	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
+
+	fd = open(buf, O_RDONLY);
+	if (fd < 0) {
+		perror("gpio/get-value");
+		return fd;
+	}
+
+	if(read(fd, &ch, 1) <= 0) {
+		result = -1;
+	}
+	else {
+		if (ch != '0') {
+		*value = 1;
+		} else {
+		*value = 0;
+		}
+	}
+
+	close(fd);
+	return result;
+}
+
+
+/****************************************************************
+ * gpio_set_edge
+ ****************************************************************/
+
+int gpio_set_edge(unsigned int gpio, char *edge)
+{
+	int fd, result = 0;
+	char buf[MAX_BUF];
+
+	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/edge", gpio);
+
+	fd = open(buf, O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/set-edge");
+		return fd;
+	}
+
+	if(write(fd, edge, strlen(edge) + 1) < 0)
+		result = -1;
+	close(fd);
+	return result;
+}
+
+/****************************************************************
+ * gpio_fd_open
+ ****************************************************************/
+
+int gpio_fd_open(unsigned int gpio, int writeFlag)
+{
+	int fd;
+	char buf[MAX_BUF];
+
+	snprintf(buf, sizeof(buf), SYSFS_GPIO_DIR "/gpio%d/value", gpio);
+
+	fd = open(buf, writeFlag | O_NONBLOCK );
+	if (fd < 0) {
+		perror("gpio/fd_open");
+	}
+	return fd;
+}
+
+/****************************************************************
+ * gpio_fd_close
+ ****************************************************************/
+
+int gpio_fd_close(int fd)
+{
+	return close(fd);
+}
+
+/****************************************************************
+ * gpio_read
+ ****************************************************************/
+int gpio_read(int fd, unsigned int *value)
+{
+	int result = 0;
+	char ch;
+
+	if(read(fd, &ch, 1) <= 0) {
+		result = -1;
+	}
+	else {
+		if (ch != '0') {
+		*value = 1;
+		} else {
+		*value = 0;
+		}
+	}
+
+	return result;
+}
+
+/****************************************************************
+ * gpio_write
+ ****************************************************************/
+int gpio_write(int fd, int value)
+{
+	int result = 0;
+	//char buf[MAX_BUF];
+
+	if (value==LOW) {
+		if(write(fd, "0", 2) < 0)
+			result = -1;
+	}
+	else {
+		if(write(fd, "1", 2) < 0)
+			result = -1;
+	}
+
+	return result;
+}
+
+
+/****************************************************************
+ * gpio_dismiss
+ ****************************************************************/
+int gpio_dismiss(int fd, unsigned int gpio)
+{
+	close(fd);
+	gpio_unexport(gpio);
+	return 0;
+}
+
+/****************************************************************
+ * led_set_trigger
+ ****************************************************************/
+int led_set_trigger(unsigned int lednum, const char *trigger)
+{
+	// Set the trigger source for an onboard user LED
+	int fd, result = 0;
+	char buf[MAX_BUF];
+
+	snprintf(buf, sizeof(buf), SYSFS_LED_DIR "/beaglebone:green:usr%d/trigger", lednum);
+
+	fd = open(buf, O_WRONLY);
+	if (fd < 0) {
+		perror("gpio/led-set-trigger");
+		return fd;
+	}
+
+	if(write(fd, trigger, strlen(trigger) + 1) < 0)
+		result = -1;
+
+	close(fd);
+	return result;
+}
+