dec_pci: QOM'ify DEC 21154 PCI-PCI bridge

Introduce type constant. Introduce cast macro and drop dummy busdev
field used with FROM_SYSBUS() that would've broken SYS_BUS_DEVICE().
Avoid accessing parent fields directly.
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/dec_pci.c

@@ -40,8 +40,9 @@
 #define DEC_DPRINTF(fmt, ...)
 #endif
 
+#define DEC_21154(obj) OBJECT_CHECK(DECState, (obj), TYPE_DEC_21154)
+
 typedef struct DECState {
-    SysBusDevice busdev;
     PCIHostState host_state;
 } DECState;
 
@@ -88,16 +89,16 @@ PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn)
 
 static int pci_dec_21154_device_init(SysBusDevice *dev)
 {
-    DECState *s;
+    PCIHostState *phb;
 
-    s = FROM_SYSBUS(DECState, dev);
+    phb = FROM_SYSBUS(PCIHostState, dev);
 
-    memory_region_init_io(&s->host_state.conf_mem, &pci_host_conf_le_ops,
-                          &s->host_state, "pci-conf-idx", 0x1000);
-    memory_region_init_io(&s->host_state.data_mem, &pci_host_data_le_ops,
-                          &s->host_state, "pci-data-idx", 0x1000);
-    sysbus_init_mmio(dev, &s->host_state.conf_mem);
-    sysbus_init_mmio(dev, &s->host_state.data_mem);
+    memory_region_init_io(&phb->conf_mem, &pci_host_conf_le_ops,
+                          dev, "pci-conf-idx", 0x1000);
+    memory_region_init_io(&phb->data_mem, &pci_host_data_le_ops,
+                          dev, "pci-data-idx", 0x1000);
+    sysbus_init_mmio(dev, &phb->conf_mem);
+    sysbus_init_mmio(dev, &phb->data_mem);
     return 0;
 }
 
@@ -134,7 +135,7 @@ static void pci_dec_21154_device_class_init(ObjectClass *klass, void *data)
 }
 
 static const TypeInfo pci_dec_21154_device_info = {
-    .name          = "dec-21154-sysbus",
+    .name          = TYPE_DEC_21154,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(DECState),
     .class_init    = pci_dec_21154_device_class_init,

hw/dec_pci.h

@@ -3,6 +3,8 @@
 
 #include "qemu-common.h"
 
+#define TYPE_DEC_21154 "dec-21154-sysbus"
+
 PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn);
 
 #endif