From 0fa0ec300a20802def6a9c92d2abe5ed325d46a0 Mon Sep 17 00:00:00 2001
From: connor rigby <konnorrigby@gmail.com>
Date: Tue, 9 Oct 2018 08:43:02 -0700
Subject: [PATCH 1/1] Fix SPIDEV interrupt and GPIO double export

---
 drivers/Linux/GPIO.cpp      | 22 +++++++++++++++-------
 drivers/Linux/interrupt.cpp | 17 -----------------
 2 files changed, 15 insertions(+), 24 deletions(-)

diff --git a/c_src/MySensors/drivers/Linux/GPIO.cpp b/c_src/MySensors/drivers/Linux/GPIO.cpp
index 84e9f45..48d1f6e 100644
--- a/c_src/MySensors/drivers/Linux/GPIO.cpp
+++ b/c_src/MySensors/drivers/Linux/GPIO.cpp
@@ -20,6 +20,7 @@
 #include "GPIO.h"
 #include <dirent.h>
 #include <stdio.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
@@ -110,19 +111,27 @@ GPIOClass::~GPIOClass()
 
 void GPIOClass::pinMode(uint8_t pin, uint8_t mode)
 {
-	FILE *f;
-
 	if (pin > lastPinNum) {
 		return;
 	}
 
-	f = fopen("/sys/class/gpio/export", "w");
-	fprintf(f, "%d\n", pin);
-	fclose(f);
-
+	FILE *f;
 	int counter = 0;
 	char file[128];
 	sprintf(file, "/sys/class/gpio/gpio%d/direction", pin);
+	
+	f = fopen(file, "r");
+	if(f != NULL) {
+		fclose(f);
+	} else {
+		f = fopen("/sys/class/gpio/export", "w");
+		if(f == NULL) {
+			logError("Could not export: %s\n", strerror(errno));
+		}
+		fprintf(f, "%d\n", pin);
+		fclose(f);
+		sleep(1);
+	}
 
 	while ((f = fopen(file,"w")) == NULL) {
 		// Wait 10 seconds for the file to be accessible if not open on first attempt
@@ -140,7 +149,6 @@ void GPIOClass::pinMode(uint8_t pin, uint8_t mode)
 	}
 
 	exportedPins[pin] = 1;
-
 	fclose(f);
 }
 
diff --git a/c_src/MySensors/drivers/Linux/interrupt.cpp b/c_src/MySensors/drivers/Linux/interrupt.cpp
index 395c217..a0dc710 100644
--- a/c_src/MySensors/drivers/Linux/interrupt.cpp
+++ b/c_src/MySensors/drivers/Linux/interrupt.cpp
@@ -142,26 +142,9 @@ void attachInterrupt(uint8_t gpioPin, void (*func)(), uint8_t mode)
 		usleep(1000);
 	}
 
-	// Export pin for interrupt
-	if ((fd = fopen("/sys/class/gpio/export", "w")) == NULL) {
-		logError("attachInterrupt: Unable to export pin %d for interrupt: %s\n", gpioPin, strerror(errno));
-		exit(1);
-	}
-	fprintf(fd, "%d\n", gpioPin);
-	fclose(fd);
-
 	// Wait a bit the system to create /sys/class/gpio/gpio<GPIO number>
 	usleep(1000);
 
-	snprintf(fName, sizeof(fName), "/sys/class/gpio/gpio%d/direction", gpioPin) ;
-	if ((fd = fopen (fName, "w")) == NULL) {
-		logError("attachInterrupt: Unable to open GPIO direction interface for pin %d: %s\n",
-		         gpioPin, strerror(errno));
-		exit(1) ;
-	}
-	fprintf(fd, "in\n") ;
-	fclose(fd) ;
-
 	snprintf(fName, sizeof(fName), "/sys/class/gpio/gpio%d/edge", gpioPin) ;
 	if ((fd = fopen(fName, "w")) == NULL) {
 		logError("attachInterrupt: Unable to open GPIO edge interface for pin %d: %s\n", gpioPin,
-- 
2.19.0