kernel: timeout: z_add_timeout to return expiration tick

Add return value to z_add_timeout. It returns system tick when timeout
will expire.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

kernel/include/timeout_q.h

@@ -30,8 +30,11 @@ static inline void z_init_timeout(struct _timeout *to)
 	sys_dnode_init(&to->node);
 }
 
-void z_add_timeout(struct _timeout *to, _timeout_func_t fn,
-		   k_timeout_t timeout);
+/* Adds the timeout to the queue.
+ *
+ * @return Absolute tick value when timeout will expire.
+ */
+k_ticks_t z_add_timeout(struct _timeout *to, _timeout_func_t fn, k_timeout_t timeout);
 
 int z_abort_timeout(struct _timeout *to);
 
@@ -53,9 +56,9 @@ static inline void z_init_thread_timeout(struct _thread_base *thread_base)
 
 extern void z_thread_timeout(struct _timeout *timeout);
 
-static inline void z_add_thread_timeout(struct k_thread *thread, k_timeout_t ticks)
+static inline k_ticks_t z_add_thread_timeout(struct k_thread *thread, k_timeout_t ticks)
 {
-	z_add_timeout(&thread->base.timeout, z_thread_timeout, ticks);
+	return z_add_timeout(&thread->base.timeout, z_thread_timeout, ticks);
 }
 
 static inline void z_abort_thread_timeout(struct k_thread *thread)
@@ -84,10 +87,11 @@ k_ticks_t z_timeout_remaining(const struct _timeout *timeout);
 #define z_get_next_timeout_expiry() ((int32_t) K_TICKS_FOREVER)
 #define z_set_timeout_expiry(ticks, is_idle) do {} while (false)
 
-static inline void z_add_thread_timeout(struct k_thread *thread, k_timeout_t ticks)
+static inline k_ticks_t z_add_thread_timeout(struct k_thread *thread, k_timeout_t ticks)
 {
 	ARG_UNUSED(thread);
 	ARG_UNUSED(ticks);
+	return 0;
 }
 
 #endif /* CONFIG_SYS_CLOCK_EXISTS */

kernel/timeout.c

@@ -99,11 +99,12 @@ static int32_t next_timeout(int32_t ticks_elapsed)
 	return ret;
 }
 
-void z_add_timeout(struct _timeout *to, _timeout_func_t fn,
-		   k_timeout_t timeout)
+k_ticks_t z_add_timeout(struct _timeout *to, _timeout_func_t fn, k_timeout_t timeout)
 {
+	k_ticks_t ticks = 0;
+
 	if (K_TIMEOUT_EQ(timeout, K_FOREVER)) {
-		return;
+		return 0;
 	}
 
 #ifdef CONFIG_KERNEL_COHERENCE
@@ -122,10 +123,12 @@ void z_add_timeout(struct _timeout *to, _timeout_func_t fn,
 			ticks_elapsed = elapsed();
 			has_elapsed = true;
 			to->dticks = timeout.ticks + 1 + ticks_elapsed;
+			ticks = curr_tick + to->dticks;
 		} else {
-			k_ticks_t ticks = Z_TICK_ABS(timeout.ticks) - curr_tick;
+			k_ticks_t dticks = Z_TICK_ABS(timeout.ticks) - curr_tick;
 
-			to->dticks = MAX(1, ticks);
+			to->dticks = MAX(1, dticks);
+			ticks = timeout.ticks;
 		}
 
 		for (t = first(); t != NULL; t = next(t)) {
@@ -151,6 +154,8 @@ void z_add_timeout(struct _timeout *to, _timeout_func_t fn,
 			sys_clock_set_timeout(next_timeout(ticks_elapsed), false);
 		}
 	}
+
+	return ticks;
 }
 
 int z_abort_timeout(struct _timeout *to)

tests/kernel/timer/timer_error_case/src/main.c

@@ -325,8 +325,8 @@ ZTEST_USER(timer_api_error, test_timer_user_data_set_null)
 	k_thread_join(tid, K_FOREVER);
 }
 
-extern void z_add_timeout(struct _timeout *to, _timeout_func_t fn,
-			  k_timeout_t timeout);
+extern k_ticks_t z_add_timeout(struct _timeout *to, _timeout_func_t fn, k_timeout_t timeout);
+
 static void test_timer_handle(struct _timeout *t)
 {
 	/**do nothing here**/