LXR qemu/hw/ssi/ssi.c

   1/*
   2 * QEMU Synchronous Serial Interface support
   3 *
   4 * Copyright (c) 2009 CodeSourcery.
   5 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
   6 * Copyright (c) 2012 PetaLogix Pty Ltd.
   7 * Written by Paul Brook
   8 *
   9 * This code is licensed under the GNU GPL v2.
  10 *
  11 * Contributions after 2012-01-13 are licensed under the terms of the
  12 * GNU GPL, version 2 or (at your option) any later version.
  13 */
  14
  15#include "qemu/osdep.h"
  16#include "hw/ssi/ssi.h"
  17#include "migration/vmstate.h"
  18#include "qemu/module.h"
  19#include "qapi/error.h"
  20#include "qom/object.h"
  21
  22struct SSIBus {
  23    BusState parent_obj;
  24};
  25
  26#define TYPE_SSI_BUS "SSI"
  27OBJECT_DECLARE_SIMPLE_TYPE(SSIBus, SSI_BUS)
  28
  29static const TypeInfo ssi_bus_info = {
  30    .name = TYPE_SSI_BUS,
  31    .parent = TYPE_BUS,
  32    .instance_size = sizeof(SSIBus),
  33};
  34
  35static void ssi_cs_default(void *opaque, int n, int level)
  36{
  37    SSIPeripheral *s = SSI_PERIPHERAL(opaque);
  38    bool cs = !!level;
  39    assert(n == 0);
  40    if (s->cs != cs) {
  41        if (s->spc->set_cs) {
  42            s->spc->set_cs(s, cs);
  43        }
  44    }
  45    s->cs = cs;
  46}
  47
  48static uint32_t ssi_transfer_raw_default(SSIPeripheral *dev, uint32_t val)
  49{
  50    SSIPeripheralClass *ssc = dev->spc;
  51
  52    if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  53        (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  54        ssc->cs_polarity == SSI_CS_NONE) {
  55        return ssc->transfer(dev, val);
  56    }
  57    return 0;
  58}
  59
  60static void ssi_peripheral_realize(DeviceState *dev, Error **errp)
  61{
  62    SSIPeripheral *s = SSI_PERIPHERAL(dev);
  63    SSIPeripheralClass *ssc = SSI_PERIPHERAL_GET_CLASS(s);
  64
  65    if (ssc->transfer_raw == ssi_transfer_raw_default &&
  66            ssc->cs_polarity != SSI_CS_NONE) {
  67        qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  68    }
  69    s->spc = ssc;
  70
  71    ssc->realize(s, errp);
  72}
  73
  74static void ssi_peripheral_class_init(ObjectClass *klass, void *data)
  75{
  76    SSIPeripheralClass *ssc = SSI_PERIPHERAL_CLASS(klass);
  77    DeviceClass *dc = DEVICE_CLASS(klass);
  78
  79    dc->realize = ssi_peripheral_realize;
  80    dc->bus_type = TYPE_SSI_BUS;
  81    if (!ssc->transfer_raw) {
  82        ssc->transfer_raw = ssi_transfer_raw_default;
  83    }
  84}
  85
  86static const TypeInfo ssi_peripheral_info = {
  87    .name = TYPE_SSI_PERIPHERAL,
  88    .parent = TYPE_DEVICE,
  89    .class_init = ssi_peripheral_class_init,
  90    .class_size = sizeof(SSIPeripheralClass),
  91    .abstract = true,
  92};
  93
  94bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp)
  95{
  96    return qdev_realize_and_unref(dev, &bus->parent_obj, errp);
  97}
  98
  99DeviceState *ssi_create_peripheral(SSIBus *bus, const char *name)
 100{
 101    DeviceState *dev = qdev_new(name);
 102
 103    ssi_realize_and_unref(dev, bus, &error_fatal);
 104    return dev;
 105}
 106
 107SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 108{
 109    BusState *bus;
 110    bus = qbus_new(TYPE_SSI_BUS, parent, name);
 111    return SSI_BUS(bus);
 112}
 113
 114uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 115{
 116    BusState *b = BUS(bus);
 117    BusChild *kid;
 118    uint32_t r = 0;
 119
 120    QTAILQ_FOREACH(kid, &b->children, sibling) {
 121        SSIPeripheral *p = SSI_PERIPHERAL(kid->child);
 122        r |= p->spc->transfer_raw(p, val);
 123    }
 124
 125    return r;
 126}
 127
 128const VMStateDescription vmstate_ssi_peripheral = {
 129    .name = "SSISlave",
 130    .version_id = 1,
 131    .minimum_version_id = 1,
 132    .fields = (VMStateField[]) {
 133        VMSTATE_BOOL(cs, SSIPeripheral),
 134        VMSTATE_END_OF_LIST()
 135    }
 136};
 137
 138static void ssi_peripheral_register_types(void)
 139{
 140    type_register_static(&ssi_bus_info);
 141    type_register_static(&ssi_peripheral_info);
 142}
 143
 144type_init(ssi_peripheral_register_types)
 145