sys/ztimer: Name callback types

sys/include/ztimer.h

@@ -288,6 +288,11 @@ typedef struct ztimer_base ztimer_base_t;
  */
 typedef struct ztimer_clock ztimer_clock_t;
 
+/**
+ * @brief Type of callbacks in @ref ztimer_t "timers"
+ */
+typedef void (*ztimer_callback_t)(void *arg);
+
 /**
  * @brief   Minimum information for each timer
  */
@@ -310,7 +315,7 @@ typedef uint32_t ztimer_now_t;  /**< type for ztimer_now() result */
  */
 typedef struct {
     ztimer_base_t base;             /**< clock list entry */
-    void (*callback)(void *arg);    /**< timer callback function pointer */
+    ztimer_callback_t callback;     /**< timer callback function pointer */
     void *arg;                      /**< timer callback argument */
 } ztimer_t;
 

sys/include/ztimer/periodic.h

@@ -80,6 +80,11 @@ extern "C" {
  */
 #define ZTIMER_PERIODIC_KEEP_GOING true
 
+/**
+ * @brief Type of callbacks in @ref ztimer_periodic_t "periodic timers"
+ */
+typedef bool (*ztimer_periodic_callback_t)(void *);
+
 /**
  * @brief   ztimer periodic structure
  */
@@ -88,7 +93,7 @@ typedef struct {
     ztimer_clock_t *clock;      /**< clock for this timer               */
     uint32_t interval;          /**< interval of this timer             */
     ztimer_now_t last;          /**< last trigger time                  */
-    bool (*callback)(void *);   /**< called on each trigger             */
+    ztimer_periodic_callback_t callback;   /**< called on each trigger             */
     void *arg;                  /**< argument for callback              */
 } ztimer_periodic_t;