2 files changed, 12 insertions, 1 deletions
diff --git a/hw/core/clock.c b/hw/core/clock.c
index 3c0daf7d4c..7066282f7b 100644
--- a/hw/core/clock.c
+++ b/hw/core/clock.c
@@ -34,11 +34,16 @@ void clock_clear_callback(Clock *clk)
     clock_set_callback(clk, NULL, NULL);
 }
 
-void clock_set(Clock *clk, uint64_t period)
+bool clock_set(Clock *clk, uint64_t period)
 {
+    if (clk->period == period) {
+        return false;
+    }
     trace_clock_set(CLOCK_PATH(clk), CLOCK_PERIOD_TO_NS(clk->period),
                     CLOCK_PERIOD_TO_NS(period));
     clk->period = period;
+
+    return true;
 }
 
 static void clock_propagate_period(Clock *clk, bool call_callbacks)
diff --git a/hw/core/qdev-clock.c b/hw/core/qdev-clock.c
index 5cc1e82e51..47ecb5b4fa 100644
--- a/hw/core/qdev-clock.c
+++ b/hw/core/qdev-clock.c
@@ -183,3 +183,9 @@ Clock *qdev_alias_clock(DeviceState *dev, const char *name,
 
     return ncl->clock;
 }
+
+void qdev_connect_clock_in(DeviceState *dev, const char *name, Clock *source)
+{
+    assert(!dev->realized);
+    clock_set_source(qdev_get_clock_in(dev, name), source);
+}