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