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