q800: add easc bool machine class property to switch between ASC and EASC

This determines whether the Apple Sound Chip (ASC) is set to enhanced mode
(default) or to original mode. The real Q800 hardware used an EASC chip however
a lot of older software only works with the older ASC chip.

Adding this as a machine parameter allows QEMU to be used as an developer aid
for testing and migrating code from ASC to EASC.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-ID: <20231004083806.757242-11-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

2 files changed, 30 insertions, 1 deletions

diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
index 249fedde7a..ac3115d328 100644
--- a/hw/m68k/q800.c
+++ b/hw/m68k/q800.c
@@ -484,7 +484,8 @@ static void q800_machine_init(MachineState *machine)
     /* Apple Sound Chip */
 
     object_initialize_child(OBJECT(machine), "asc", &m->asc, TYPE_ASC);
-    qdev_prop_set_uint8(DEVICE(&m->asc), "asctype", ASC_TYPE_EASC);
+    qdev_prop_set_uint8(DEVICE(&m->asc), "asctype", m->easc ? ASC_TYPE_EASC
+                                                            : ASC_TYPE_ASC);
     if (machine->audiodev) {
         qdev_prop_set_string(DEVICE(&m->asc), "audiodev", machine->audiodev);
     }
@@ -677,6 +678,28 @@ static void q800_machine_init(MachineState *machine)
     }
 }
 
+static bool q800_get_easc(Object *obj, Error **errp)
+{
+    Q800MachineState *ms = Q800_MACHINE(obj);
+
+    return ms->easc;
+}
+
+static void q800_set_easc(Object *obj, bool value, Error **errp)
+{
+    Q800MachineState *ms = Q800_MACHINE(obj);
+
+    ms->easc = value;
+}
+
+static void q800_init(Object *obj)
+{
+    Q800MachineState *ms = Q800_MACHINE(obj);
+
+    /* Default to EASC */
+    ms->easc = true;
+}
+
 static GlobalProperty hw_compat_q800[] = {
     { "scsi-hd", "quirk_mode_page_vendor_specific_apple", "on" },
     { "scsi-hd", "vendor", " SEAGATE" },
@@ -710,11 +733,16 @@ static void q800_machine_class_init(ObjectClass *oc, void *data)
     mc->default_ram_id = "m68k_mac.ram";
     machine_add_audiodev_property(mc);
     compat_props_add(mc->compat_props, hw_compat_q800, hw_compat_q800_len);
+
+    object_class_property_add_bool(oc, "easc", q800_get_easc, q800_set_easc);
+    object_class_property_set_description(oc, "easc",
+        "Set to off to use ASC rather than EASC");
 }
 
 static const TypeInfo q800_machine_typeinfo = {
     .name       = MACHINE_TYPE_NAME("q800"),
     .parent     = TYPE_MACHINE,
+    .instance_init = q800_init,
     .instance_size = sizeof(Q800MachineState),
     .class_init = q800_machine_class_init,
 };
diff --git a/include/hw/m68k/q800.h b/include/hw/m68k/q800.h
index 790cf433f3..fbaacd88bd 100644
--- a/include/hw/m68k/q800.h
+++ b/include/hw/m68k/q800.h
@@ -47,6 +47,7 @@
 struct Q800MachineState {
     MachineState parent_obj;
 
+    bool easc;
     M68kCPU cpu;
     MemoryRegion rom;
     GLUEState glue;