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 "qemu/module.h"
  18
  19struct SSIBus {
  20    BusState parent_obj;
  21};
  22
  23#define TYPE_SSI_BUS "SSI"
  24#define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  25
  26static const TypeInfo ssi_bus_info = {
  27    .name = TYPE_SSI_BUS,
  28    .parent = TYPE_BUS,
  29    .instance_size = sizeof(SSIBus),
  30};
  31
  32static void ssi_cs_default(void *opaque, int n, int level)
  33{
  34    SSISlave *s = SSI_SLAVE(opaque);
  35    bool cs = !!level;
  36    assert(n == 0);
  37    if (s->cs != cs) {
  38        SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  39        if (ssc->set_cs) {
  40            ssc->set_cs(s, cs);
  41        }
  42    }
  43    s->cs = cs;
  44}
  45
  46static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
  47{
  48    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
  49
  50    if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  51            (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  52            ssc->cs_polarity == SSI_CS_NONE) {
  53        return ssc->transfer(dev, val);
  54    }
  55    return 0;
  56}
  57
  58static void ssi_slave_realize(DeviceState *dev, Error **errp)
  59{
  60    SSISlave *s = SSI_SLAVE(dev);
  61    SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  62
  63    if (ssc->transfer_raw == ssi_transfer_raw_default &&
  64            ssc->cs_polarity != SSI_CS_NONE) {
  65        qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  66    }
  67
  68    ssc->realize(s, errp);
  69}
  70
  71static void ssi_slave_class_init(ObjectClass *klass, void *data)
  72{
  73    SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
  74    DeviceClass *dc = DEVICE_CLASS(klass);
  75
  76    dc->realize = ssi_slave_realize;
  77    dc->bus_type = TYPE_SSI_BUS;
  78    if (!ssc->transfer_raw) {
  79        ssc->transfer_raw = ssi_transfer_raw_default;
  80    }
  81}
  82
  83static const TypeInfo ssi_slave_info = {
  84    .name = TYPE_SSI_SLAVE,
  85    .parent = TYPE_DEVICE,
  86    .class_init = ssi_slave_class_init,
  87    .class_size = sizeof(SSISlaveClass),
  88    .abstract = true,
  89};
  90
  91DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
  92{
  93    return qdev_create(BUS(bus), name);
  94}
  95
  96DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  97{
  98    DeviceState *dev = ssi_create_slave_no_init(bus, name);
  99
 100    qdev_init_nofail(dev);
 101    return dev;
 102}
 103
 104SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 105{
 106    BusState *bus;
 107    bus = qbus_create(TYPE_SSI_BUS, parent, name);
 108    return SSI_BUS(bus);
 109}
 110
 111uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 112{
 113    BusState *b = BUS(bus);
 114    BusChild *kid;
 115    SSISlaveClass *ssc;
 116    uint32_t r = 0;
 117
 118    QTAILQ_FOREACH(kid, &b->children, sibling) {
 119        SSISlave *slave = SSI_SLAVE(kid->child);
 120        ssc = SSI_SLAVE_GET_CLASS(slave);
 121        r |= ssc->transfer_raw(slave, val);
 122    }
 123
 124    return r;
 125}
 126
 127const VMStateDescription vmstate_ssi_slave = {
 128    .name = "SSISlave",
 129    .version_id = 1,
 130    .minimum_version_id = 1,
 131    .fields = (VMStateField[]) {
 132        VMSTATE_BOOL(cs, SSISlave),
 133        VMSTATE_END_OF_LIST()
 134    }
 135};
 136
 137static void ssi_slave_register_types(void)
 138{
 139    type_register_static(&ssi_bus_info);
 140    type_register_static(&ssi_slave_info);
 141}
 142
 143type_init(ssi_slave_register_types)
 144
 145typedef struct SSIAutoConnectArg {
 146    qemu_irq **cs_linep;
 147    SSIBus *bus;
 148} SSIAutoConnectArg;
 149
 150static int ssi_auto_connect_slave(Object *child, void *opaque)
 151{
 152    SSIAutoConnectArg *arg = opaque;
 153    SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
 154    qemu_irq cs_line;
 155
 156    if (!dev) {
 157        return 0;
 158    }
 159
 160    cs_line = qdev_get_gpio_in_named(DEVICE(dev), SSI_GPIO_CS, 0);
 161    qdev_set_parent_bus(DEVICE(dev), BUS(arg->bus));
 162    **arg->cs_linep = cs_line;
 163    (*arg->cs_linep)++;
 164    return 0;
 165}
 166
 167void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
 168                             SSIBus *bus)
 169{
 170    SSIAutoConnectArg arg = {
 171        .cs_linep = &cs_line,
 172        .bus = bus
 173    };
 174
 175    object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
 176}
 177