Now than all QOM users provides the input clock, do not allow
using a CPS without input clock connected.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201012095804.3335117-21-f4bug@amsat.org>
---
 hw/mips/cps.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/mips/cps.c b/hw/mips/cps.c
index af7b58c4bdd..c624821315a 100644
--- a/hw/mips/cps.c
+++ b/hw/mips/cps.c
@@ -74,6 +74,11 @@ static void mips_cps_realize(DeviceState *dev, Error **errp)
     bool itu_present = false;
     bool saar_present = false;
 
+    if (!clock_get(s->clock)) {
+        error_setg(errp, "CPS input clock is not connected to an output clock");
+        return;
+    }
+
     for (i = 0; i < s->num_vp; i++) {
         cpu = MIPS_CPU(object_new(s->cpu_type));
 
-- 
2.26.2