Refactor timer APIs to use helper macros

Timer APIs no longer require memory operations now that timers are
statically allocated with embedded list nodes.

This change removes redundant allocation paths and uses the
timer_from_node() helper to align timer access with the embedded
list node design.

Author: vicLin8712

kernel/timer.c

@@ -275,8 +275,9 @@ int32_t mo_timer_create(void *(*callback)(void *arg),
     if (unlikely(timer_subsystem_init() != ERR_OK))
         return ERR_FAIL;
 
-    timer_t *t = malloc(sizeof(timer_t));
-    if (unlikely(!t))
+    /* Try to get a static timer from the pool */
+    timer_t *t = get_timer();
+    if (!t)
         return ERR_FAIL;
 
     NOSCHED_ENTER();
@@ -290,13 +291,11 @@ int32_t mo_timer_create(void *(*callback)(void *arg),
     t->last_expected_fire_tick = 0;
     t->mode = TIMER_DISABLED;
     t->_reserved = 0;
+    t->t_node.next = NULL;
+    t->t_running_node.next = NULL;
 
     /* Insert into sorted all_timers_list */
-    if (unlikely(timer_insert_sorted_by_id(t) != ERR_OK)) {
-        NOSCHED_LEAVE();
-        free(t);
-        return ERR_FAIL;
-    }
+    timer_insert_sorted_timer_list(t);
 
     /* Add to cache */
     cache_timer(t->id, t);
@@ -318,11 +317,11 @@ int32_t mo_timer_destroy(uint16_t id)
         return ERR_FAIL;
     }
 
-    timer_t *t = (timer_t *) node->data;
+    timer_t *t = timer_from_node(node);
 
     /* Remove from active list if running */
     if (t->mode != TIMER_DISABLED)
-        timer_remove_item_by_data(kcb->timer_list, t);
+        timer_remove_from_running_list(kcb->timer_list, t);
 
     /* Remove from cache */
     for (int i = 0; i < 4; i++) {
@@ -342,9 +341,7 @@ int32_t mo_timer_destroy(uint16_t id)
         all_timers_list->length--;
     }
 
-    free(t);
-    return_timer_node(node);
-
+    return_timer(t);
     NOSCHED_LEAVE();
     return ERR_OK;
 }
@@ -366,18 +363,14 @@ int32_t mo_timer_start(uint16_t id, uint8_t mode)
 
     /* Remove from active list if already running */
     if (t->mode != TIMER_DISABLED)
-        timer_remove_item_by_data(kcb->timer_list, t);
+        timer_remove_from_running_list(kcb->timer_list, t);
 
     /* Configure and start timer */
     t->mode = mode;
     t->last_expected_fire_tick = mo_ticks() + MS_TO_TICKS(t->period_ms);
     t->deadline_ticks = t->last_expected_fire_tick;
 
-    if (unlikely(timer_sorted_insert(t) != ERR_OK)) {
-        t->mode = TIMER_DISABLED;
-        NOSCHED_LEAVE();
-        return ERR_FAIL;
-    }
+    timer_sorted_insert_running_list(t);
 
     NOSCHED_LEAVE();
     return ERR_OK;
@@ -396,7 +389,7 @@ int32_t mo_timer_cancel(uint16_t id)
         return ERR_FAIL;
     }
 
-    timer_remove_item_by_data(kcb->timer_list, t);
+    timer_remove_from_running_list(kcb->timer_list, t);
     t->mode = TIMER_DISABLED;
 
     NOSCHED_LEAVE();