doc: efm32: include gpio_common

gpio_common was built, but wasn't picked up by any documentation.
Use the peripheral_apis style from stm32, but try out the #pragma once
style.  Downside is you don't get warnings if you include an sub layer
.h file.  Upsides are
* no ifdef/endif blocks
* no /**@cond*/ /**@endcond*/ blocks
* that's enough win!

include/libopencm3/efm32/common/gpio_common.h

@@ -1,3 +1,5 @@
+/** @addtogroup gpio_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_GPIO_H
-#define LIBOPENCM3_EFM32_GPIO_H
+#pragma once
 
 #include <libopencm3/efm32/memorymap.h>
 #include <libopencm3/cm3/common.h>
 
+/**@{*/
+
 #define GPIO_P(i)		(GPIO_BASE + (0x24 * (i)))
 #define GPIO_PA			GPIO_P(0)
 #define GPIO_PB			GPIO_P(1)
@@ -326,5 +329,4 @@ void gpio_port_config_lock(uint32_t gpio_port, uint16_t gpios);
 
 END_DECLS
 
-#endif
-
+/**@}*/

include/libopencm3/efm32/common/gpio_common_hglg.h

@@ -1,3 +1,5 @@
+/** @addtogroup gpio_defines
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -17,15 +19,13 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/** @cond */
-#if defined(LIBOPENCM3_GPIO_H)
-/** @endcond */
-#ifndef LIBOPENCM3_EFM32_GPIO_COMMON_HGLG_H
-#define LIBOPENCM3_EFM32_GPIO_COMMON_HGLG_H
+#pragma once
 
 #include <libopencm3/efm32/memorymap.h>
 #include <libopencm3/cm3/common.h>
 
+/**@{*/
+
 #define GPIO_P(i)		(GPIO_BASE + (0x24 * (i)))
 #define GPIO_PA			GPIO_P(0)
 #define GPIO_PB			GPIO_P(1)
@@ -329,9 +329,4 @@ void gpio_port_config_lock(uint32_t gpio_port, uint16_t gpios);
 
 END_DECLS
 
-#endif
-/** @cond */
-#else
-#warning "gpio_common_hglg.h should not be included explicitly, only via gpio.h"
-#endif
-/** @endcond */
+/**@}*/

include/libopencm3/efm32/ezr32wg/gpio.h

@@ -1,3 +1,11 @@
+/** @defgroup gpio_defines GPIO Defines
+ *
+ * @brief <b>Defined Constants and Types for the EZR32WG GPIO 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_GPIO_H
-#define LIBOPENCM3_EFM32_EZR32WG_GPIO_H
+#pragma once
 
 #include <libopencm3/efm32/common/gpio_common.h>
-
-#endif

include/libopencm3/efm32/hg/gpio.h

@@ -1,3 +1,11 @@
+/** @defgroup gpio_defines GPIO Defines
+ *
+ * @brief <b>Defined Constants and Types for the EFM32HG GPIO module</b>
+ *
+ * @ingroup EFM32HG_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -15,9 +23,6 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_GPIO_H
-#define LIBOPENCM3_GPIO_H
+#pragma once
 
 #include <libopencm3/efm32/common/gpio_common_hglg.h>
-
-#endif

include/libopencm3/efm32/lg/gpio.h

@@ -1,3 +1,11 @@
+/** @defgroup gpio_defines GPIO Defines
+ *
+ * @brief <b>Defined Constants and Types for the EFM32LG GPIO module</b>
+ *
+ * @ingroup EFM32LG_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
 /*
  * This file is part of the libopencm3 project.
  *
@@ -15,9 +23,6 @@
  * along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LIBOPENCM3_GPIO_H
-#define LIBOPENCM3_GPIO_H
+#pragma once
 
 #include <libopencm3/efm32/common/gpio_common.h>
-
-#endif

include/libopencm3/efm32/wg/gpio.h

@@ -1,3 +1,11 @@
+/** @defgroup gpio_defines GPIO Defines
+ *
+ * @brief <b>Defined Constants and Types for the EFM32WG GPIO 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_GPIO_H
-#define LIBOPENCM3_EFM32_WG_GPIO_H
+#pragma once
 
 #include <libopencm3/efm32/common/gpio_common.h>
-
-#endif