Prep for C++ port

src/avclan/target/avr-attiny3216/media_avr.h

@@ -5,8 +5,11 @@
 // transaction guard (phy_avr.c's AVCLAN_stopEvent). Not part of the public
 // mediacontrol.h interface.
 
-#ifndef MEDIA_AVR_H
-#define MEDIA_AVR_H
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 // Keep the TCA0 press waveform roughly in sync while a bus transaction has
 // masked interrupts (runs the OVF ISR body early if an overflow is imminent).
@@ -14,4 +17,6 @@
 // ATOMIC_BLOCK).
 void mediacontrol_syncDuringMask();
 
-#endif // MEDIA_AVR_H
+#ifdef __cplusplus
+}
+#endif

src/avclan/target/avr-attiny3216/timing_avr.h

@@ -1,8 +1,7 @@
 // Copyright (C) 2015 Allen Hill <allenofthehills@gmail.com>
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-#ifndef TIMING_AVR_H
-#define TIMING_AVR_H
+#pragma once
 
 // AVR ATtiny3216 timing parameters. Derives F_CPU (needed by avr-libc, e.g.
 // util/delay.h) and the bus-timer (TCB) tick period from the CMake-provided
@@ -65,5 +64,3 @@
 #define TICK_US (TCB_TICK / 1000.0)
 
 #include "timing.h"
-
-#endif // TIMING_AVR_H