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 "hw/ssi.h"
  16
  17struct SSIBus {
  18    BusState parent_obj;
  19};
  20
  21#define TYPE_SSI_BUS "SSI"
  22#define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  23
  24static const TypeInfo ssi_bus_info = {
  25    .name = TYPE_SSI_BUS,
  26    .parent = TYPE_BUS,
  27    .instance_size = sizeof(SSIBus),
  28};
  29
  30static void ssi_cs_default(void *opaque, int n, int level)
  31{
  32    SSISlave *s = SSI_SLAVE(opaque);
  33    bool cs = !!level;
  34    assert(n == 0);
  35    if (s->cs != cs) {
  36        SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  37        if (ssc->set_cs) {
  38            ssc->set_cs(s, cs);
  39        }
  40    }
  41    s->cs = cs;
  42}
  43
  44static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
  45{
  46    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
  47
  48    if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  49            (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  50            ssc->cs_polarity == SSI_CS_NONE) {
  51        return ssc->transfer(dev, val);
  52    }
  53    return 0;
  54}
  55
  56static int ssi_slave_init(DeviceState *dev)
  57{
  58    SSISlave *s = SSI_SLAVE(dev);
  59    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  60
  61    if (ssc->transfer_raw == ssi_transfer_raw_default &&
  62            ssc->cs_polarity != SSI_CS_NONE) {
  63        qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  64    }
  65
  66    return ssc->init(s);
  67}
  68
  69static void ssi_slave_class_init(ObjectClass *klass, void *data)
  70{
  71    SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
  72    DeviceClass *dc = DEVICE_CLASS(klass);
  73
  74    dc->init = ssi_slave_init;
  75    dc->bus_type = TYPE_SSI_BUS;
  76    if (!ssc->transfer_raw) {
  77        ssc->transfer_raw = ssi_transfer_raw_default;
  78    }
  79}
  80
  81static const TypeInfo ssi_slave_info = {
  82    .name = TYPE_SSI_SLAVE,
  83    .parent = TYPE_DEVICE,
  84    .class_init = ssi_slave_class_init,
  85    .class_size = sizeof(SSISlaveClass),
  86    .abstract = true,
  87};
  88
  89DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
  90{
  91    return qdev_create(BUS(bus), name);
  92}
  93
  94DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  95{
  96    DeviceState *dev = ssi_create_slave_no_init(bus, name);
  97
  98    qdev_init_nofail(dev);
  99    return dev;
 100}
 101
 102SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 103{
 104    BusState *bus;
 105    bus = qbus_create(TYPE_SSI_BUS, parent, name);
 106    return SSI_BUS(bus);
 107}
 108
 109uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 110{
 111    BusState *b = BUS(bus);
 112    BusChild *kid;
 113    SSISlaveClass *ssc;
 114    uint32_t r = 0;
 115
 116    QTAILQ_FOREACH(kid, &b->children, sibling) {
 117        SSISlave *slave = SSI_SLAVE(kid->child);
 118        ssc = SSI_SLAVE_GET_CLASS(slave);
 119        r |= ssc->transfer_raw(slave, val);
 120    }
 121
 122    return r;
 123}
 124
 125const VMStateDescription vmstate_ssi_slave = {
 126    .name = "SSISlave",
 127    .version_id = 1,
 128    .minimum_version_id = 1,
 129    .fields = (VMStateField[]) {
 130        VMSTATE_BOOL(cs, SSISlave),
 131        VMSTATE_END_OF_LIST()
 132    }
 133};
 134
 135static void ssi_slave_register_types(void)
 136{
 137    type_register_static(&ssi_bus_info);
 138    type_register_static(&ssi_slave_info);
 139}
 140
 141type_init(ssi_slave_register_types)
 142
 143typedef struct SSIAutoConnectArg {
 144    qemu_irq **cs_linep;
 145    SSIBus *bus;
 146} SSIAutoConnectArg;
 147
 148static int ssi_auto_connect_slave(Object *child, void *opaque)
 149{
 150    SSIAutoConnectArg *arg = opaque;
 151    SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
 152    qemu_irq cs_line;
 153
 154    if (!dev) {
 155        return 0;
 156    }
 157
 158    cs_line = qdev_get_gpio_in_named(DEVICE(dev), SSI_GPIO_CS, 0);
 159    qdev_set_parent_bus(DEVICE(dev), BUS(arg->bus));
 160    **arg->cs_linep = cs_line;
 161    (*arg->cs_linep)++;
 162    return 0;
 163}
 164
 165void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
 166                             SSIBus *bus)
 167{
 168    SSIAutoConnectArg arg = {
 169        .cs_linep = &cs_line,
 170        .bus = bus
 171    };
 172
 173    object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
 174}
 175