[3/9] m48t59: add a Nvram interface

diff --git a/hw/timer/m48t59.c b/hw/timer/m48t59.c
index c46b63c..c5e74ce 100644
--- a/hw/timer/m48t59.c
+++ b/hw/timer/m48t59.c
@@ -798,6 +798,24 @@  static int m48t59_init1(SysBusDevice *dev)
     return 0;
 }
 
+static uint32_t m48txx_isa_read(Nvram *obj, uint32_t addr)
+{
+    M48txxISAState *d = M48TXX_ISA(obj);
+    return m48t59_read(&d->state, addr);
+}
+
+static void m48txx_isa_write(Nvram *obj, uint32_t addr, uint32_t val)
+{
+    M48txxISAState *d = M48TXX_ISA(obj);
+    m48t59_write(&d->state, addr, val);
+}
+
+static void m48txx_isa_toggle_lock(Nvram *obj, int lock)
+{
+    M48txxISAState *d = M48TXX_ISA(obj);
+    m48t59_toggle_lock(&d->state, lock);
+}
+
 static Property m48t59_isa_properties[] = {
     DEFINE_PROP_UINT32("iobase", M48txxISAState, io_base, 0x74),
     DEFINE_PROP_END_OF_LIST(),
@@ -806,10 +824,14 @@  static Property m48t59_isa_properties[] = {
 static void m48txx_isa_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
+    NvramClass *nc = NVRAM_CLASS(klass);
 
     dc->realize = m48t59_isa_realize;
     dc->reset = m48t59_reset_isa;
     dc->props = m48t59_isa_properties;
+    nc->read = m48txx_isa_read;
+    nc->write = m48txx_isa_write;
+    nc->toggle_lock = m48txx_isa_toggle_lock;
 }
 
 static void m48txx_isa_concrete_class_init(ObjectClass *klass, void *data)
@@ -820,13 +842,35 @@  static void m48txx_isa_concrete_class_init(ObjectClass *klass, void *data)
     u->info = *info;
 }
 
+static uint32_t m48txx_sysbus_read(Nvram *obj, uint32_t addr)
+{
+    M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
+    return m48t59_read(&d->state, addr);
+}
+
+static void m48txx_sysbus_write(Nvram *obj, uint32_t addr, uint32_t val)
+{
+    M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
+    m48t59_write(&d->state, addr, val);
+}
+
+static void m48txx_sysbus_toggle_lock(Nvram *obj, int lock)
+{
+    M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
+    m48t59_toggle_lock(&d->state, lock);
+}
+
 static void m48txx_sysbus_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    NvramClass *nc = NVRAM_CLASS(klass);
 
     k->init = m48t59_init1;
     dc->reset = m48t59_reset_sysbus;
+    nc->read = m48txx_sysbus_read;
+    nc->write = m48txx_sysbus_write;
+    nc->toggle_lock = m48txx_sysbus_toggle_lock;
 }
 
 static void m48txx_sysbus_concrete_class_init(ObjectClass *klass, void *data)
@@ -837,12 +881,22 @@  static void m48txx_sysbus_concrete_class_init(ObjectClass *klass, void *data)
     u->info = *info;
 }
 
+static const TypeInfo nvram_info = {
+    .name = TYPE_NVRAM,
+    .parent = TYPE_INTERFACE,
+    .class_size = sizeof(NvramClass),
+};
+
 static const TypeInfo m48txx_sysbus_type_info = {
     .name = TYPE_M48TXX_SYS_BUS,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(M48txxSysBusState),
     .abstract = true,
     .class_init = m48txx_sysbus_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_NVRAM },
+        { }
+    }
 };
 
 static const TypeInfo m48txx_isa_type_info = {
@@ -851,6 +905,10 @@  static const TypeInfo m48txx_isa_type_info = {
     .instance_size = sizeof(M48txxISAState),
     .abstract = true,
     .class_init = m48txx_isa_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_NVRAM },
+        { }
+    }
 };
 
 static void m48t59_register_types(void)
@@ -867,6 +925,7 @@  static void m48t59_register_types(void)
     };
     int i;
 
+    type_register_static(&nvram_info);
     type_register_static(&m48txx_sysbus_type_info);
     type_register_static(&m48txx_isa_type_info);
 
diff --git a/include/hw/timer/m48t59.h b/include/hw/timer/m48t59.h
index 8217522..ddbbda2 100644
--- a/include/hw/timer/m48t59.h
+++ b/include/hw/timer/m48t59.h
@@ -1,6 +1,9 @@ 
 #ifndef NVRAM_H
 #define NVRAM_H
 
+#include "qemu-common.h"
+#include "qom/object.h"
+
 /* NVRAM helpers */
 typedef uint32_t (*nvram_read_t)(void *private, uint32_t addr);
 typedef void (*nvram_write_t)(void *private, uint32_t addr, uint32_t val);
@@ -34,4 +37,25 @@  M48t59State *m48t59_init_isa(ISABus *bus, uint32_t io_base, uint16_t size,
 M48t59State *m48t59_init(qemu_irq IRQ, hwaddr mem_base,
                          uint32_t io_base, uint16_t size, int type);
 
+#define TYPE_NVRAM "nvram"
+
+#define NVRAM_CLASS(klass) \
+    OBJECT_CLASS_CHECK(NvramClass, (klass), TYPE_NVRAM)
+#define NVRAM_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(NvramClass, (obj), TYPE_NVRAM)
+#define NVRAM(obj) \
+    INTERFACE_CHECK(Nvram, (obj), TYPE_NVRAM)
+
+typedef struct Nvram {
+    Object parent;
+} Nvram;
+
+typedef struct NvramClass {
+    InterfaceClass parent;
+
+    uint32_t (*read)(Nvram *obj, uint32_t addr);
+    void (*write)(Nvram *obj, uint32_t addr, uint32_t val);
+    void (*toggle_lock)(Nvram *obj, int lock);
+} NvramClass;
+
 #endif /* !NVRAM_H */