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 licenced under the GNU GPL v2.
   8  */
   9
  10 #include "ssi.h"
  11
  12 struct SSIBus {
  13     BusState qbus;
  14 };
  15
  16 static struct BusInfo ssi_bus_info = {
  17     .name = "SSI",
  18     .size = sizeof(SSIBus),
  19 };
  20
  21 static int ssi_slave_init(DeviceState *dev, DeviceInfo *base_info)
  22 {
  23     SSISlaveInfo *info = container_of(base_info, SSISlaveInfo, qdev);
  24     SSISlave *s = SSI_SLAVE_FROM_QDEV(dev);
  25     SSIBus *bus;
  26
  27     bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
  28     if (QLIST_FIRST(&bus->qbus.children) != dev
  29         || QLIST_NEXT(dev, sibling) != NULL) {
  30         hw_error("Too many devices on SSI bus");
  31     }
  32
  33     s->info = info;
  34     return info->init(s);
  35 }
  36
  37 void ssi_register_slave(SSISlaveInfo *info)
  38 {
  39     assert(info->qdev.size >= sizeof(SSISlave));
  40     info->qdev.init = ssi_slave_init;
  41     info->qdev.bus_info = &ssi_bus_info;
  42     qdev_register(&info->qdev);
  43 }
  44
  45 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  46 {
  47     DeviceState *dev;
  48     dev = qdev_create(&bus->qbus, name);
  49     qdev_init_nofail(dev);
  50     return dev;
  51 }
  52
  53 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
  54 {
  55     BusState *bus;
  56     bus = qbus_create(&ssi_bus_info, parent, name);
  57     return FROM_QBUS(SSIBus, bus);
  58 }
  59
  60 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
  61 {
  62     DeviceState *dev;
  63     SSISlave *slave;
  64     dev = QLIST_FIRST(&bus->qbus.children);
  65     if (!dev) {
  66         return 0;
  67     }
  68     slave = SSI_SLAVE_FROM_QDEV(dev);
  69     return slave->info->transfer(slave, val);
  70 }