hw/ssi.c

   1 /*
   2  * QEMU Synchronous Serial Interface support
   3  *
   4  * Copyright (c) 2009 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licensed under the GNU GPL v2.
   8  *
   9  * Contributions after 2012-01-13 are licensed under the terms of the
  10  * GNU GPL, version 2 or (at your option) any later version.
  11  */
  12
  13 #include "ssi.h"
  14
  15 struct SSIBus {
  16     BusState qbus;
  17 };
  18
  19 #define TYPE_SSI_BUS "SSI"
  20 #define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  21
  22 static const TypeInfo ssi_bus_info = {
  23     .name = TYPE_SSI_BUS,
  24     .parent = TYPE_BUS,
  25     .instance_size = sizeof(SSIBus),
  26 };
  27
  28 static int ssi_slave_init(DeviceState *dev)
  29 {
  30     SSISlave *s = SSI_SLAVE(dev);
  31     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  32     SSIBus *bus;
  33
  34     bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
  35     if (QTAILQ_FIRST(&bus->qbus.children) != dev
  36         || QTAILQ_NEXT(dev, sibling) != NULL) {
  37         hw_error("Too many devices on SSI bus");
  38     }
  39
  40     return ssc->init(s);
  41 }
  42
  43 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  44 {
  45     DeviceClass *dc = DEVICE_CLASS(klass);
  46     dc->init = ssi_slave_init;
  47     dc->bus_type = TYPE_SSI_BUS;
  48 }
  49
  50 static TypeInfo ssi_slave_info = {
  51     .name = TYPE_SSI_SLAVE,
  52     .parent = TYPE_DEVICE,
  53     .class_init = ssi_slave_class_init,
  54     .class_size = sizeof(SSISlaveClass),
  55     .abstract = true,
  56 };
  57
  58 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  59 {
  60     DeviceState *dev;
  61     dev = qdev_create(&bus->qbus, name);
  62     qdev_init_nofail(dev);
  63     return dev;
  64 }
  65
  66 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
  67 {
  68     BusState *bus;
  69     bus = qbus_create(TYPE_SSI_BUS, parent, name);
  70     return FROM_QBUS(SSIBus, bus);
  71 }
  72
  73 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
  74 {
  75     DeviceState *dev;
  76     SSISlave *slave;
  77     SSISlaveClass *ssc;
  78     dev = QTAILQ_FIRST(&bus->qbus.children);
  79     if (!dev) {
  80         return 0;
  81     }
  82     slave = SSI_SLAVE(dev);
  83     ssc = SSI_SLAVE_GET_CLASS(slave);
  84     return ssc->transfer(slave, val);
  85 }
  86
  87 static void ssi_slave_register_types(void)
  88 {
  89     type_register_static(&ssi_bus_info);
  90     type_register_static(&ssi_slave_info);
  91 }
  92
  93 type_init(ssi_slave_register_types)