module: timer: add API to update timer status without alarm

Some device need interrupt to update internal status. Add new
driver API to do this if there is no acitve alarm.

Change-Id: I6a3106beb8dce8de7de29dfa5ff5742a9fd9692b
Signed-off-by: Joe Zhu <chunguang.zhu@verisilicon.com>

module/timer/include/mod_timer.h

@@ -120,6 +120,13 @@ struct mod_timer_driver_api {
 
     /*! Get counter frequency */
     int (*get_frequency)(fwk_id_t dev_id, uint32_t *value);
+
+    /*!
+     * Timer device may need to update internal status periodically.
+     * So interrupt is triggered even there is no active alarm.
+     * Only will be called if interrupt is not an alarm timeout. Optional
+     */
+    void (*update)(fwk_id_t dev_id);
 };
 
 /*!

module/timer/src/mod_timer.c

@@ -557,8 +557,12 @@ static void timer_isr(uintptr_t ctx_ptr)
         (struct alarm_sub_element_ctx *)fwk_list_pop_head(&ctx->alarms_active);
 
     if (alarm == NULL) {
-        /* Timer interrupt triggered without any alarm in the active queue */
-        fwk_unexpected();
+        if (ctx->driver->update) {
+            ctx->driver->update(ctx->driver_dev_id);
+        } else {
+            /* Timer interrupt triggered without any alarm in the active queue */
+            fwk_unexpected();
+        }
         return;
     }