diff --git a/include/libopencm3/efm32/ezr32wg/dac.h b/include/libopencm3/efm32/ezr32wg/dac.h
index aba83df2..8624e638 100644
--- a/include/libopencm3/efm32/ezr32wg/dac.h
+++ b/include/libopencm3/efm32/ezr32wg/dac.h
@@ -1,3 +1,11 @@
+/** @defgroup dac_defines DAC Defines
+ *
+ * @brief <b>Defined Constants and Types for the D/A Converter module</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_DAC_H
-#define LIBOPENCM3_EFM32_EZR32WG_DAC_H
+#pragma once
 
 #include <libopencm3/efm32/common/dac_common.h>
-
-#endif
diff --git a/include/libopencm3/efm32/lg/dac.h b/include/libopencm3/efm32/lg/dac.h
index 5ad9dfe0..3611a248 100644
--- a/include/libopencm3/efm32/lg/dac.h
+++ b/include/libopencm3/efm32/lg/dac.h
@@ -1,3 +1,11 @@
+/** @defgroup dac_defines DAC Defines
+ *
+ * @brief <b>Defined Constants and Types for the D/A Converter module</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_DAC_H
-#define LIBOPENCM3_EFM32_LG_DAC_H
+#pragma once
 
 #include <libopencm3/efm32/common/dac_common.h>
-
-#endif
diff --git a/include/libopencm3/efm32/wg/dac.h b/include/libopencm3/efm32/wg/dac.h
index 5285c3ce..87538bf0 100644
--- a/include/libopencm3/efm32/wg/dac.h
+++ b/include/libopencm3/efm32/wg/dac.h
@@ -1,3 +1,11 @@
+/** @defgroup dac_defines DAC Defines
+ *
+ * @brief <b>Defined Constants and Types for the D/A Converter module</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_DAC_H
-#define LIBOPENCM3_EFM32_WG_DAC_H
+#pragma once
 
 #include <libopencm3/efm32/common/dac_common.h>
-
-#endif
diff --git a/lib/efm32/common/dac_common.c b/lib/efm32/common/dac_common.c
index 4d5c1036..4d982401 100644
--- a/lib/efm32/common/dac_common.c
+++ b/lib/efm32/common/dac_common.c
@@ -1,3 +1,6 @@
+/** @addtogroup dac_file DAC peripheral API
+ * @ingroup peripheral_apis
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -22,6 +25,8 @@
 
 #include <libopencm3/efm32/dac.h>
 
+/**@{*/
+
 /**
  * Set DAC refresh cycle
  * @param[in] dac DAC (use DACx)
@@ -166,3 +171,5 @@ void dac_disable_channel(uint32_t dac, enum dac_ch ch)
 {
 	DAC_CHx_CTRL(dac, ch) &= ~DAC_CH_CTRL_REFREN;
 }
+
+/**@}*/
\ No newline at end of file