multiplexer: cleanup

1 files changed, 6 insertions, 5 deletions

diff --git a/multiplexer.c b/multiplexer.c
index 5f82ee5..474f7e6 100644
--- a/multiplexer.c
+++ b/multiplexer.c
@@ -1,9 +1,10 @@
-#include <stdio.h>
+#ifndef SKIP_GPIO
 #include <stdlib.h>
 #include <fcntl.h>
 #include <sys/mman.h>
+#endif
+#include <stdio.h>
 #include <unistd.h>
-#include <errno.h>
 #include <string.h>
 #include <pthread.h>
 
@@ -22,13 +23,13 @@ void printButton(int g)
 //
 // Set up a memory regions to access GPIO
 //
-void multiplexer_setup_root()
+int multiplexer_setup_root()
 {
 #ifndef SKIP_GPIO
   /* open /dev/mem */
   if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
     perror("can't open /dev/mem");
-    exit(-1);
+    return EXIT_FAILURE;
   }
 
   /* mmap GPIO */
@@ -45,7 +46,7 @@ void multiplexer_setup_root()
 
   if (gpio_map == MAP_FAILED) {
     perror("mmap error");
-    exit(-1);
+    return EXIT_FAILURE;
   }
 
   // Always use volatile pointer!