diff --git a/include/libopencm3/efm32/common/emu_common.h b/include/libopencm3/efm32/common/emu_common.h
index 7d220c50..f33020bc 100644
--- a/include/libopencm3/efm32/common/emu_common.h
+++ b/include/libopencm3/efm32/common/emu_common.h
@@ -1,3 +1,5 @@
+/** @addtogroup emu_defines
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,12 +19,13 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_EFM32_EMU_H
-#define LIBOPENCM3_EFM32_EMU_H
+#pragma once
 
 #include <libopencm3/efm32/memorymap.h>
 #include <libopencm3/cm3/common.h>
 
+/**@{*/
+
 #define EMU_CTRL			MMIO32(EMU_BASE + 0x000)
 #define EMU_LOCK			MMIO32(EMU_BASE + 0x008)
 #define EMU_AUXCTRL			MMIO32(EMU_BASE + 0x024)
@@ -185,5 +188,4 @@
 	(((v) << EMU_BUBODUNREGCAL_THRES_SHIFT) & \
 	 EMU_BUBODUNREGCAL_THRES_MASK)
 
-#endif
-
+/**@}*/
\ No newline at end of file
diff --git a/include/libopencm3/efm32/ezr32wg/emu.h b/include/libopencm3/efm32/ezr32wg/emu.h
index 054a748a..d0e532c2 100644
--- a/include/libopencm3/efm32/ezr32wg/emu.h
+++ b/include/libopencm3/efm32/ezr32wg/emu.h
@@ -1,3 +1,11 @@
+/** @defgroup emu_defines EMU Defines
+ *
+ * @brief <b>Defined Constants and Types for the Energy Management Unit</b>
+ *
+ * @ingroup EZR32WG_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,9 +25,6 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_EFM32_EZR32WG_EMU_H
-#define LIBOPENCM3_EFM32_EZR32WG_EMU_H
+#pragma once
 
 #include <libopencm3/efm32/common/emu_common.h>
-
-#endif
diff --git a/include/libopencm3/efm32/lg/emu.h b/include/libopencm3/efm32/lg/emu.h
index d104663b..92b350c0 100644
--- a/include/libopencm3/efm32/lg/emu.h
+++ b/include/libopencm3/efm32/lg/emu.h
@@ -1,3 +1,11 @@
+/** @defgroup emu_defines EMU Defines
+ *
+ * @brief <b>Defined Constants and Types for the Energy Management Unit</b>
+ *
+ * @ingroup EFM32LG_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,9 +25,6 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_EFM32_LG_EMU_H
-#define LIBOPENCM3_EFM32_LG_EMU_H
+#pragma once
 
 #include <libopencm3/efm32/common/emu_common.h>
-
-#endif
diff --git a/include/libopencm3/efm32/wg/emu.h b/include/libopencm3/efm32/wg/emu.h
index a1a6d318..11f38c41 100644
--- a/include/libopencm3/efm32/wg/emu.h
+++ b/include/libopencm3/efm32/wg/emu.h
@@ -1,3 +1,11 @@
+/** @defgroup emu_defines EMU Defines
+ *
+ * @brief <b>Defined Constants and Types for the Energy Management Unit</b>
+ *
+ * @ingroup EFM32WG_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,9 +25,6 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_EFM32_WG_EMU_H
-#define LIBOPENCM3_EFM32_WG_EMU_H
+#pragma once
 
 #include <libopencm3/efm32/common/emu_common.h>
-
-#endif
diff --git a/lib/efm32/common/emu_common.c b/lib/efm32/common/emu_common.c
new file mode 100644
index 00000000..1015e8e0
--- /dev/null
+++ b/lib/efm32/common/emu_common.c
@@ -0,0 +1,15 @@
+/** @addtogroup emu_file EMU peripheral API
+ * @ingroup peripheral_apis
+ * @brief Energy Management Unit helper functions.
+ *
+ * <b>NO</b> helper functions exist. Only header definitions are available.
+ * Delete these lines if/when you add actual helper APIs.
+ * @copyright See @ref lgpl_license
+ */
+
+#include <libopencm3/efm32/emu.h>
+
+/**@{*/
+
+/**@}*/
+
diff --git a/lib/efm32/ezr32wg/Makefile b/lib/efm32/ezr32wg/Makefile
index 44763d7e..2ea15784 100644
--- a/lib/efm32/ezr32wg/Makefile
+++ b/lib/efm32/ezr32wg/Makefile
@@ -43,6 +43,7 @@ OBJS += burtc_common.o
 OBJS += cmu_common.o
 OBJS += dac_common.o
 OBJS += dma_common.o
+OBJS += emu_common.o
 OBJS += gpio_common.o
 OBJS += prs_common.o
 OBJS += timer_common.o
diff --git a/lib/efm32/lg/Makefile b/lib/efm32/lg/Makefile
index 94ca814c..de10765a 100644
--- a/lib/efm32/lg/Makefile
+++ b/lib/efm32/lg/Makefile
@@ -43,6 +43,7 @@ OBJS += burtc_common.o
 OBJS += cmu_common.o
 OBJS += dac_common.o
 OBJS += dma_common.o
+OBJS += emu_common.o
 OBJS += gpio_common.o
 OBJS += prs_common.o
 OBJS += timer_common.o
diff --git a/lib/efm32/wg/Makefile b/lib/efm32/wg/Makefile
index f2ca009f..ea30bbcd 100644
--- a/lib/efm32/wg/Makefile
+++ b/lib/efm32/wg/Makefile
@@ -43,6 +43,7 @@ OBJS += burtc_common.o
 OBJS += cmu_common.o
 OBJS += dac_common.o
 OBJS += dma_common.o
+OBJS += emu_common.o
 OBJS += gpio_common.o
 OBJS += prs_common.o
 OBJS += timer_common.o