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     BusChild *kid;
  34
  35     bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
  36     kid = QTAILQ_FIRST(&bus->qbus.children);
  37     if (kid->child != dev || QTAILQ_NEXT(kid, sibling) != NULL) {
  38         hw_error("Too many devices on SSI bus");
  39     }
  40
  41     return ssc->init(s);
  42 }
  43
  44 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  45 {
  46     DeviceClass *dc = DEVICE_CLASS(klass);
  47     dc->init = ssi_slave_init;
  48     dc->bus_type = TYPE_SSI_BUS;
  49 }
  50
  51 static TypeInfo ssi_slave_info = {
  52     .name = TYPE_SSI_SLAVE,
  53     .parent = TYPE_DEVICE,
  54     .class_init = ssi_slave_class_init,
  55     .class_size = sizeof(SSISlaveClass),
  56     .abstract = true,
  57 };
  58
  59 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  60 {
  61     DeviceState *dev;
  62     dev = qdev_create(&bus->qbus, name);
  63     qdev_init_nofail(dev);
  64     return dev;
  65 }
  66
  67 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
  68 {
  69     BusState *bus;
  70     bus = qbus_create(TYPE_SSI_BUS, parent, name);
  71     return FROM_QBUS(SSIBus, bus);
  72 }
  73
  74 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
  75 {
  76     BusChild *kid;
  77     SSISlave *slave;
  78     SSISlaveClass *ssc;
  79
  80     kid = QTAILQ_FIRST(&bus->qbus.children);
  81     if (!kid) {
  82         return 0;
  83     }
  84     slave = SSI_SLAVE(kid->child);
  85     ssc = SSI_SLAVE_GET_CLASS(slave);
  86     return ssc->transfer(slave, val);
  87 }
  88
  89 static void ssi_slave_register_types(void)
  90 {
  91     type_register_static(&ssi_bus_info);
  92     type_register_static(&ssi_slave_info);
  93 }
  94
  95 type_init(ssi_slave_register_types)