overhauled documentation

includes minor refactoring in example code and modification of how the
generic and the tinygecko specific vector.h go together (bringing it in
line with stm32/f1's memorymap.h)

include/libopencm3/efm32/tinygecko/cmu.h

@@ -17,17 +17,29 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* this interface correspons to the description in
- * d0034_efm32tg_reference_manual.pdf section 11. */
+/** @file
+ *
+ * Definitions for the CMU (Clock Management Unit).
+ *
+ * This corresponds to the description in d0034_efm32tg_reference_manual.pdf
+ * section 11.
+ *
+ * @see CMU_registers
+ */
+/* FIXME: i'd prefer not to @see CMU_registers but have some direct link placed
+ * automatically from a file to its groups */
 
 #ifndef LIBOPENCM3_EFM32_TINYGECKO_CMU_H
 #define LIBOPENCM3_EFM32_TINYGECKO_CMU_H
 
 #include <libopencm3/cm3/common.h>
 
-#define CMU_BASE 0x400C8000 /* according to d0034_efm32tg_reference_manual.pdf figure 5.2 */
+#define CMU_BASE 0x400C8000 /**< Register base address for the CMU according to d0034_efm32tg_reference_manual.pdf figure 5.2. */
 
-/* this is d0034_efm32tg_reference_manual.pdf section 11.4 */
+/** These definitions reflect d0034_efm32tg_reference_manual.pdf section 11.4.
+ *
+ * @defgroup CMU_registers CMU registers
+ * @{ */
 
 #define CMU_CTRL		MMIO32(CMU_BASE + 0x000)
 #define CMU_HFCORECLKDIV	MMIO32(CMU_BASE + 0x004)
@@ -58,8 +70,14 @@
 #define CMU_ROUTE		MMIO32(CMU_BASE + 0x080)
 #define CMU_LOCK		MMIO32(CMU_BASE + 0x084)
 
-/* this is incomplete because i'm impatient and want a working result
- * quickly */
+/** @} */
+
+/**
+ * This section is incomplete because i'm impatient and want a working result
+ * quickly
+ *
+ * @todo Include all bits and bit groups from the manual.
+ */
 
 #define CMU_HFPERCLKEN0_GPIO (1<<6)
 

include/libopencm3/efm32/tinygecko/devicerevision.h

@@ -1,3 +1,7 @@
+/* FIXME: proper documentation, see where this fits, if we need this at all
+ * etc. this was just a first attempt at implementing something easy with
+ * MMIO32. */
+
 /* this implements d0034_efm32tg_reference_manual.pdf's 7.3.4 "Device Revision"
  * section */
 

include/libopencm3/efm32/tinygecko/gpio.h

@@ -17,18 +17,36 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/* this interface corresponds to the description in
- * d0034_efm32tg_reference_manual.pdf section 28. the interface tries to be
- * close to stm32/f1's gpio interface. */
+/** @file
+ *
+ * Definitions for the GPIO subsystem (General Purpose Input Output).
+ *
+ * This corresponds to the description in d0034_efm32tg_reference_manual.pdf
+ * section 28.
+ *
+ * @see GPIO_registers
+ * @see GPIO_MODE_values
+ */
+/* FIXME: i'd prefer not to @see CMU_registers but have some direct link placed
+ * automatically from a file to its groups */
 
 #ifndef LIBOPENCM3_EFM32_TINYGECKO_GPIO_H
 #define LIBOPENCM3_EFM32_TINYGECKO_GPIO_H
 
 #include <libopencm3/cm3/common.h>
 
-#define GPIO_BASE 0x40006000 /* according to d0034_efm32tg_reference_manual.pdf figure 5.2 */
+#define GPIO_BASE 0x40006000 /**< Register base address for the GPIO according to d0034_efm32tg_reference_manual.pdf figure 5.2. */
 
-/* this is rather straight forward d0034_efm32tg_reference_manual.pdf section 28.4 */
+/** These definitions reflect d0034_efm32tg_reference_manual.pdf section 28.4
+ *
+ * The bulk of the registers defined here (like GPIO_PA_CTRL) will not be used
+ * inside the convenience functions, but are provided for direct access.
+ *
+ * @todo This section could profit from bit-banding.
+ *
+ * @defgroup GPIO_registers GPIO registers
+ * @{
+ */
 #define GPIO_Px_CTRL_OFFSET	0x000
 #define GPIO_Px_MODEL_OFFSET	0x004
 #define GPIO_Px_MODEH_OFFSET	0x008
@@ -122,10 +140,24 @@
 #define GPIO_EM4WUPOL		MMIO32(GPIO_BASE + 0x138)
 #define GPIO_EM4WUCAUSE		MMIO32(GPIO_BASE + 0x13C)
 
-/* these are the modes defined for the MODEx fields in the MODEL/MODEH
- * registers, named as in d0034_efm32tg_reference_manual.pdf's sections
- * 28.5.2/28.5.3. for explanations of what they really do, rather see section
- * 28.3.1. */
+/** @} */
+
+/** These are the modes defined for the MODEx fields in the MODEL/MODEH
+ * registers.
+ *
+ * For example, to set the mode for the 3rd pin of port A to pushpull, set
+ * `GPIO_PA_MODEL = GPIO_MODE_PUSHPULL << (3*4);`.
+ *
+ * @todo Update the example as soon as there are convenience functions to do
+ * this properly.
+ *
+ * They are named as in d0034_efm32tg_reference_manual.pdf's sections
+ * 28.5.2/28.5.3. For explanations of what they really do, rather see section
+ * 28.3.1.
+ *
+ * @defgroup GPIO_MODE_values GPIO MODE values
+ * @{
+ */
 
 #define GPIO_MODE_DISABLED			0
 #define GPIO_MODE_INPUT				1
@@ -144,6 +176,8 @@
 #define GPIO_MODE_WIREDANDDRIVEPULLUP		14
 #define GPIO_MODE_WIREDANDDRIVEPULLUPFILTER	15
 
+/** @} */
+
 //void gpio_set(u32 gpioport, u16 gpios);
 //void gpio_clear(u32 gpioport, u16 gpios);
 //void gpio_toggle(u32 gpioport, u16 gpios);

include/libopencm3/efm32/tinygecko/vector.h

@@ -1,11 +1,15 @@
-/* this implements d0002_efm32_cortex-m3_reference_manual.pdf's table 1.1's "number of interrupts" line. */
-
+/** @file
+ *
+ * Definitions for vector tables on Tiny Gecko systems.
+ *
+ * @see include/libopencm3/efm32/vector.h
+ *
+ * @todo The definitions of the individual IRQs will go here too.
+ * */
 
 #ifndef LIBOPENCM3_EFM32_TINYGECKO_VECTOR_H
 #define LIBOPENCM3_EFM32_TINYGECKO_VECTOR_H
 
-#define EFM32_VECTOR_NIRQ 23
-
-#include "../vector.h"
+#define EFM32_VECTOR_NIRQ 23 /**< See d0002_efm32_cortex-m3_reference_manual.pdf's table 1.1's "number of interrupts" line */
 
 #endif

include/libopencm3/efm32/vector.h

@@ -1,21 +1,29 @@
-/* this implements d0002_efm32_cortex-m3_reference_manual.pdf's figure 2.2.
+/** @file
  *
- * the structure of the vector table is implemented independently of the vector
- * table, as it can be relocated to other memory locations too.
+ * Definitions for handling vector tables.
  *
- * don't include this file directly; rather, include the family's vector.h
- * file, which defines the number of interrupts (EFM_VECTOR_NIRQ) from table
- * 1.1 */
+ * This implements d0002_efm32_cortex-m3_reference_manual.pdf's figure 2.2.
+ *
+ * The structure of the vector table is implemented independently of the system
+ * vector table starting at memory position 0x0, as it can be relocated to
+ * other memory locations too.
+ */
 
 #ifndef LIBOPENCM3_EFM32_VECTOR_H
 #define LIBOPENCM3_EFM32_VECTOR_H
 
 #include <libopencm3/cm3/common.h>
 
-typedef void (*efm32_vector_table_entry_t)(void);
+#ifdef TINYGECKO
+#	include <libopencm3/efm32/tinygecko/vector.h>
+#else
+#	error "efm32 family not defined."
+#endif
+
+typedef void (*efm32_vector_table_entry_t)(void); /**< Type of an interrupt function. Only used to avoid hard-to-read function pointers in the efm32_vector_table_t struct. */
 
 typedef struct {
-	unsigned int *initial_sp_value;
+	unsigned int *initial_sp_value; /**< The value the stack pointer is set to initially */
 	efm32_vector_table_entry_t reset;
 	efm32_vector_table_entry_t nmi;
 	efm32_vector_table_entry_t hard_fault;