LXR qemu/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
  17static 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
  23static void nubus_slot_write(void *opaque, hwaddr addr, uint64_t val,
  24                             unsigned int size)
  25{
  26    /* read only */
  27}
  28
  29
  30static uint64_t nubus_slot_read(void *opaque, hwaddr addr,
  31                                unsigned int size)
  32{
  33    return 0;
  34}
  35
  36static 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
  46static void nubus_super_slot_write(void *opaque, hwaddr addr, uint64_t val,
  47                                   unsigned int size)
  48{
  49    /* read only */
  50}
  51
  52static uint64_t nubus_super_slot_read(void *opaque, hwaddr addr,
  53                                      unsigned int size)
  54{
  55    return 0;
  56}
  57
  58static 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
  68static 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
  76static 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
  91static void nubus_class_init(ObjectClass *oc, void *data)
  92{
  93    BusClass *bc = BUS_CLASS(oc);
  94
  95    bc->realize = nubus_realize;
  96}
  97
  98static 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
 106static void nubus_register_types(void)
 107{
 108    type_register_static(&nubus_bus_info);
 109}
 110
 111type_init(nubus_register_types)
 112