hw/nubus/nubus-bus.c

   1 /*
   2  * QEMU Macintosh Nubus
   3  *
   4  * Copyright (c) 2013-2018 Laurent Vivier <laurent@vivier.eu>
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "hw/nubus/nubus.h"
  13 #include "qapi/error.h"
  14
  15
  16 static NubusBus *nubus_find(void)
  17 {
  18     /* Returns NULL unless there is exactly one nubus device */
  19     return NUBUS_BUS(object_resolve_path_type("", TYPE_NUBUS_BUS, NULL));
  20 }
  21
  22 static void nubus_slot_write(void *opaque, hwaddr addr, uint64_t val,
  23                              unsigned int size)
  24 {
  25     /* read only */
  26 }
  27
  28
  29 static uint64_t nubus_slot_read(void *opaque, hwaddr addr,
  30                                 unsigned int size)
  31 {
  32     return 0;
  33 }
  34
  35 static const MemoryRegionOps nubus_slot_ops = {
  36     .read  = nubus_slot_read,
  37     .write = nubus_slot_write,
  38     .endianness = DEVICE_BIG_ENDIAN,
  39     .valid = {
  40         .min_access_size = 1,
  41         .max_access_size = 1,
  42     },
  43 };
  44
  45 static void nubus_super_slot_write(void *opaque, hwaddr addr, uint64_t val,
  46                                    unsigned int size)
  47 {
  48     /* read only */
  49 }
  50
  51 static uint64_t nubus_super_slot_read(void *opaque, hwaddr addr,
  52                                       unsigned int size)
  53 {
  54     return 0;
  55 }
  56
  57 static const MemoryRegionOps nubus_super_slot_ops = {
  58     .read  = nubus_super_slot_read,
  59     .write = nubus_super_slot_write,
  60     .endianness = DEVICE_BIG_ENDIAN,
  61     .valid = {
  62         .min_access_size = 1,
  63         .max_access_size = 1,
  64     },
  65 };
  66
  67 static void nubus_realize(BusState *bus, Error **errp)
  68 {
  69     if (!nubus_find()) {
  70         error_setg(errp, "at most one %s device is permitted", TYPE_NUBUS_BUS);
  71         return;
  72     }
  73 }
  74
  75 static void nubus_init(Object *obj)
  76 {
  77     NubusBus *nubus = NUBUS_BUS(obj);
  78
  79     memory_region_init_io(&nubus->super_slot_io, obj, &nubus_super_slot_ops,
  80                           nubus, "nubus-super-slots",
  81                           NUBUS_SUPER_SLOT_NB * NUBUS_SUPER_SLOT_SIZE);
  82
  83     memory_region_init_io(&nubus->slot_io, obj, &nubus_slot_ops,
  84                           nubus, "nubus-slots",
  85                           NUBUS_SLOT_NB * NUBUS_SLOT_SIZE);
  86
  87     nubus->current_slot = NUBUS_FIRST_SLOT;
  88 }
  89
  90 static void nubus_class_init(ObjectClass *oc, void *data)
  91 {
  92     BusClass *bc = BUS_CLASS(oc);
  93
  94     bc->realize = nubus_realize;
  95 }
  96
  97 static const TypeInfo nubus_bus_info = {
  98     .name = TYPE_NUBUS_BUS,
  99     .parent = TYPE_BUS,
 100     .instance_size = sizeof(NubusBus),
 101     .instance_init = nubus_init,
 102     .class_init = nubus_class_init,
 103 };
 104
 105 static void nubus_register_types(void)
 106 {
 107     type_register_static(&nubus_bus_info);
 108 }
 109
 110 type_init(nubus_register_types)