1 files changed, 43 insertions, 0 deletions
diff --git a/hw/ssi/ssi.c b/hw/ssi/ssi.c
index d54a109bee..1f3e540ab8 100644
--- a/hw/ssi/ssi.c
+++ b/hw/ssi/ssi.c
@@ -13,6 +13,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/qdev-properties.h"
 #include "hw/ssi/ssi.h"
 #include "migration/vmstate.h"
 #include "qemu/module.h"
@@ -26,10 +27,46 @@ struct SSIBus {
 #define TYPE_SSI_BUS "SSI"
 OBJECT_DECLARE_SIMPLE_TYPE(SSIBus, SSI_BUS)
 
+DeviceState *ssi_get_cs(SSIBus *bus, uint8_t cs_index)
+{
+    BusState *b = BUS(bus);
+    BusChild *kid;
+
+    QTAILQ_FOREACH(kid, &b->children, sibling) {
+        SSIPeripheral *kid_ssi = SSI_PERIPHERAL(kid->child);
+        if (kid_ssi->cs_index == cs_index) {
+            return kid->child;
+        }
+    }
+
+    return NULL;
+}
+
+static bool ssi_bus_check_address(BusState *b, DeviceState *dev, Error **errp)
+{
+    SSIPeripheral *s = SSI_PERIPHERAL(dev);
+
+    if (ssi_get_cs(SSI_BUS(b), s->cs_index)) {
+        error_setg(errp, "CS index '0x%x' in use by a %s device", s->cs_index,
+                   object_get_typename(OBJECT(dev)));
+        return false;
+    }
+
+    return true;
+}
+
+static void ssi_bus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+
+    k->check_address = ssi_bus_check_address;
+}
+
 static const TypeInfo ssi_bus_info = {
     .name = TYPE_SSI_BUS,
     .parent = TYPE_BUS,
     .instance_size = sizeof(SSIBus),
+    .class_init = ssi_bus_class_init,
 };
 
 static void ssi_cs_default(void *opaque, int n, int level)
@@ -71,6 +108,11 @@ static void ssi_peripheral_realize(DeviceState *dev, Error **errp)
     ssc->realize(s, errp);
 }
 
+static Property ssi_peripheral_properties[] = {
+    DEFINE_PROP_UINT8("cs", SSIPeripheral, cs_index, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void ssi_peripheral_class_init(ObjectClass *klass, void *data)
 {
     SSIPeripheralClass *ssc = SSI_PERIPHERAL_CLASS(klass);
@@ -81,6 +123,7 @@ static void ssi_peripheral_class_init(ObjectClass *klass, void *data)
     if (!ssc->transfer_raw) {
         ssc->transfer_raw = ssi_transfer_raw_default;
     }
+    device_class_set_props(dc, ssi_peripheral_properties);
 }
 
 static const TypeInfo ssi_peripheral_info = {