cleanup

src/mixer.h

@@ -1,11 +1,20 @@
-#pragma once
+/**
+ * Copyright (c) 2017 rnlf
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef MIXER_H
+#define MIXER_H
 
 #include <stdint.h>
 #include "source.h"
 
-
 void mixer_init(void);
 void mixer_deinit(void);
 int16_t const* mixer_getNextBlock(void);
 void mixer_play(source_t const *source);
 void mixer_mix(void);
+
+#endif