From 99d4f70ef8c0b379fc6f18835241e1bf69de881a Mon Sep 17 00:00:00 2001
From: Nicolae Rosia <nicolae.rosia@gmail.com>
Date: Thu, 18 May 2017 22:15:54 +0300
Subject: [PATCH] linux_gpio: check if pin is already exported

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>
---
 src/drivers/linux_gpio/linux_gpio.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/drivers/linux_gpio/linux_gpio.cpp b/src/drivers/linux_gpio/linux_gpio.cpp
index 4053c87f2f..5447246906 100644
--- a/src/drivers/linux_gpio/linux_gpio.cpp
+++ b/src/drivers/linux_gpio/linux_gpio.cpp
@@ -78,6 +78,11 @@ int LinuxGPIO::_exportPin(unsigned int pin)
 	int ret;
 	int bytes_to_write;
 
+	if (_readValue(pin) != -1) {
+		/* GPIO is already exported */
+		return 0;
+	}
+
 	fd = open("/sys/class/gpio/export", O_WRONLY);
 
 	if (fd == -1) {