hw/arm/iotkit: Refactor into abstract base class and subclass

The Arm SSE-200 Subsystem for Embedded is a revised and
extended version of the older IoTKit SoC. Prepare for
adding a model of it by refactoring the IoTKit code into
an abstract base class which contains the functionality,
driven by a class data block specific to each subclass.
(This is the same approach used by the existing bcm283x
SoC family implementation.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190121185118.18550-6-peter.maydell@linaro.org

hw/arm/iotkit.c

@@ -18,6 +18,16 @@
 #include "hw/arm/iotkit.h"
 #include "hw/arm/arm.h"
 
+struct ARMSSEInfo {
+    const char *name;
+};
+
+static const ARMSSEInfo armsse_variants[] = {
+    {
+        .name = TYPE_IOTKIT,
+    },
+};
+
 /* Clock frequency in HZ of the 32KHz "slow clock" */
 #define S32KCLK (32 * 1000)
 
@@ -732,29 +742,43 @@ static void iotkit_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     IDAUInterfaceClass *iic = IDAU_INTERFACE_CLASS(klass);
+    ARMSSEClass *asc = ARMSSE_CLASS(klass);
 
     dc->realize = iotkit_realize;
     dc->vmsd = &iotkit_vmstate;
     dc->props = iotkit_properties;
     dc->reset = iotkit_reset;
     iic->check = iotkit_idau_check;
+    asc->info = data;
 }
 
-static const TypeInfo iotkit_info = {
+static const TypeInfo armsse_info = {
     .name = TYPE_ARMSSE,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(ARMSSE),
     .instance_init = iotkit_init,
-    .class_init = iotkit_class_init,
+    .abstract = true,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_IDAU_INTERFACE },
         { }
     }
 };
 
-static void iotkit_register_types(void)
+static void armsse_register_types(void)
 {
-    type_register_static(&iotkit_info);
+    int i;
+
+    type_register_static(&armsse_info);
+
+    for (i = 0; i < ARRAY_SIZE(armsse_variants); i++) {
+        TypeInfo ti = {
+            .name = armsse_variants[i].name,
+            .parent = TYPE_ARMSSE,
+            .class_init = iotkit_class_init,
+            .class_data = (void *)&armsse_variants[i],
+        };
+        type_register(&ti);
+    }
 }
 
-type_init(iotkit_register_types);
+type_init(armsse_register_types);

include/hw/arm/iotkit.h

@@ -74,15 +74,15 @@
 #include "hw/or-irq.h"
 #include "hw/core/split-irq.h"
 
-#define TYPE_ARMSSE "iotkit"
+#define TYPE_ARMSSE "arm-sse"
 #define ARMSSE(obj) OBJECT_CHECK(ARMSSE, (obj), TYPE_ARMSSE)
 
 /*
- * For the moment TYPE_IOTKIT is a synonym for TYPE_ARMSSE (and the
+ * These type names are for specific IoTKit subsystems; other than
- * latter's underlying name is left as "iotkit"); in a later
+ * instantiating them, code using these devices should always handle
- * commit it will become a subclass of TYPE_ARMSSE.
+ * them via the ARMSSE base class, so they have no IOTKIT() etc macros.
  */
-#define TYPE_IOTKIT TYPE_ARMSSE
+#define TYPE_IOTKIT "iotkit"
 
 /* We have an IRQ splitter and an OR gate input for each external PPC
  * and the 2 internal PPCs
@@ -143,4 +143,16 @@ typedef struct ARMSSE {
     uint32_t mainclk_frq;
 } ARMSSE;
 
+typedef struct ARMSSEInfo ARMSSEInfo;
+
+typedef struct ARMSSEClass {
+    DeviceClass parent_class;
+    const ARMSSEInfo *info;
+} ARMSSEClass;
+
+#define ARMSSE_CLASS(klass) \
+    OBJECT_CLASS_CHECK(ARMSSEClass, (klass), TYPE_ARMSSE)
+#define ARMSSE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(ARMSSEClass, (obj), TYPE_ARMSSE)
+
 #endif