From efb567f66701b4227d290ca26bdb5155be91e109 Mon Sep 17 00:00:00 2001
From: Mike Black W9MDB <mdblack98@yahoo.com>
Date: Sat, 17 Jun 2023 11:57:07 -0500
Subject: [PATCH] Make sure to unexport the GPIO port during close
 https://github.com/Hamlib/Hamlib/issues/1316

---
 src/gpio.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/gpio.c b/src/gpio.c
index 298b8a2d4..1b2602eee 100644
--- a/src/gpio.c
+++ b/src/gpio.c
@@ -99,7 +99,28 @@ int gpio_open(hamlib_port_t *port, int output, int on_value)
 
 int gpio_close(hamlib_port_t *port)
 {
-    return close(port->fd);
+    int retval;
+    char pathname[HAMLIB_FILPATHLEN * 2];
+    FILE *fexp;
+
+    retval = close(port->fd);
+
+    SNPRINTF(pathname, HAMLIB_FILPATHLEN, "/sys/class/gpio/unexport");
+    fexp = fopen(pathname, "w");
+
+    if (!fexp)
+    {
+        rig_debug(RIG_DEBUG_ERR,
+                  "Export GPIO%s (using %s): %s\n",
+                  port->pathname,
+                  pathname,
+                  strerror(errno));
+        return -RIG_EIO;
+    }
+
+    fprintf(fexp, "%s\n", port->pathname);
+    fclose(fexp);
+    return retval;
 }