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 void ssi_slave_init(DeviceState *dev, DeviceInfo *base_info)
  17 {
  18     SSISlaveInfo *info = container_of(base_info, SSISlaveInfo, qdev);
  19     SSISlave *s = SSI_SLAVE_FROM_QDEV(dev);
  20     SSIBus *bus;
  21
  22     bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
  23     if (LIST_FIRST(&bus->qbus.children) != dev
  24         || LIST_NEXT(dev, sibling) != NULL) {
  25         hw_error("Too many devices on SSI bus");
  26     }
  27
  28     s->info = info;
  29     info->init(s);
  30 }
  31
  32 void ssi_register_slave(SSISlaveInfo *info)
  33 {
  34     assert(info->qdev.size >= sizeof(SSISlave));
  35     info->qdev.init = ssi_slave_init;
  36     info->qdev.bus_type = BUS_TYPE_SSI;
  37     qdev_register(&info->qdev);
  38 }
  39
  40 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  41 {
  42     DeviceState *dev;
  43     dev = qdev_create(&bus->qbus, name);
  44     qdev_init(dev);
  45     return dev;
  46 }
  47
  48 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
  49 {
  50     BusState *bus;
  51     bus = qbus_create(BUS_TYPE_SSI, sizeof(SSIBus), parent, name);
  52     return FROM_QBUS(SSIBus, bus);
  53 }
  54
  55 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
  56 {
  57     DeviceState *dev;
  58     SSISlave *slave;
  59     dev = LIST_FIRST(&bus->qbus.children);
  60     if (!dev) {
  61         return 0;
  62     }
  63     slave = SSI_SLAVE_FROM_QDEV(dev);
  64     return slave->info->transfer(slave, val);
  65 }