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 static struct BusInfo ssi_bus_info = {
  20     .name = "SSI",
  21     .size = sizeof(SSIBus),
  22 };
  23
  24 static int ssi_slave_init(DeviceState *dev, DeviceInfo *base_info)
  25 {
  26     SSISlave *s = SSI_SLAVE(dev);
  27     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  28     SSIBus *bus;
  29
  30     bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
  31     if (QTAILQ_FIRST(&bus->qbus.children) != dev
  32         || QTAILQ_NEXT(dev, sibling) != NULL) {
  33         hw_error("Too many devices on SSI bus");
  34     }
  35
  36     return ssc->init(s);
  37 }
  38
  39 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  40 {
  41     DeviceClass *dc = DEVICE_CLASS(klass);
  42     dc->init = ssi_slave_init;
  43     dc->bus_info = &ssi_bus_info;
  44 }
  45
  46 static TypeInfo ssi_slave_info = {
  47     .name = TYPE_SSI_SLAVE,
  48     .parent = TYPE_DEVICE,
  49     .class_init = ssi_slave_class_init,
  50     .class_size = sizeof(SSISlaveClass),
  51     .abstract = true,
  52 };
  53
  54 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  55 {
  56     DeviceState *dev;
  57     dev = qdev_create(&bus->qbus, name);
  58     qdev_init_nofail(dev);
  59     return dev;
  60 }
  61
  62 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
  63 {
  64     BusState *bus;
  65     bus = qbus_create(&ssi_bus_info, parent, name);
  66     return FROM_QBUS(SSIBus, bus);
  67 }
  68
  69 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
  70 {
  71     DeviceState *dev;
  72     SSISlave *slave;
  73     SSISlaveClass *ssc;
  74     dev = QTAILQ_FIRST(&bus->qbus.children);
  75     if (!dev) {
  76         return 0;
  77     }
  78     slave = SSI_SLAVE(dev);
  79     ssc = SSI_SLAVE_GET_CLASS(slave);
  80     return ssc->transfer(slave, val);
  81 }
  82
  83 static void register_ssi_slave(void)
  84 {
  85     type_register_static(&ssi_slave_info);
  86 }
  87
  88 device_init(register_ssi_slave);