From e04e6199e3dda5e601b1da5e2d404d05b8f1dec0 Mon Sep 17 00:00:00 2001
From: Ivan Pelipenko <peri4ko@yandex.ru>
Date: Fri, 22 May 2020 21:58:05 +0300
Subject: [PATCH] PIGPIO user permission patch

---
 src_main/io_devices/pigpio.cpp | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src_main/io_devices/pigpio.cpp b/src_main/io_devices/pigpio.cpp
index 93dfdc53..d6d0f9e4 100644
--- a/src_main/io_devices/pigpio.cpp
+++ b/src_main/io_devices/pigpio.cpp
@@ -89,13 +89,25 @@ PIString PIGPIO::GPIOName(int gpio_num) {
 
 void PIGPIO::exportGPIO(int gpio_num) {
 #ifdef GPIO_SYS_CLASS
-	int fd = ::open(("/sys/class/gpio/" + GPIOName(gpio_num) + "/value").dataAscii(), O_RDONLY);
+	PIString valfile = "/sys/class/gpio/" + GPIOName(gpio_num) + "/value";
+	int fd = ::open(valfile.dataAscii(), O_RDONLY);
 	if (fd != -1) {
 		::close(fd);
 		return;
 	}
 	int ret = 0;
 	ret = system(PIString("echo " + PIString::fromNumber(gpio_num) + " >> /sys/class/gpio/export").dataAscii());
+	if (ret == 0) {
+		PITimeMeasurer tm;
+		while (tm.elapsed_s() < 1.) {
+			fd = ::open(valfile.dataAscii(), O_RDWR);
+			if (fd != -1) {
+				::close(fd);
+				return;
+			}
+			piMSleep(1);
+		}
+	}
 #endif
 }