qemu/hw/ssi/ssi.c

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/*
* QEMU Synchronous Serial Interface support
*
* Copyright (c) 2009 CodeSourcery.
* Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
* Copyright (c) 2012 PetaLogix Pty Ltd.
* Written by Paul Brook
*
* This code is licensed under the GNU GPL v2.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "hw/ssi/ssi.h"
#include "migration/vmstate.h"
#include "qemu/module.h"
#include "qapi/error.h"
struct SSIBus {
BusState parent_obj;
};
#define TYPE_SSI_BUS "SSI"
#define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
static const TypeInfo ssi_bus_info = {
.name = TYPE_SSI_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(SSIBus),
};
static void ssi_cs_default(void *opaque, int n, int level)
{
SSISlave *s = SSI_SLAVE(opaque);
bool cs = !!level;
assert(n == 0);
if (s->cs != cs) {
SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
if (ssc->set_cs) {
ssc->set_cs(s, cs);
}
}
s->cs = cs;
}
static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
{
SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
(!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
ssc->cs_polarity == SSI_CS_NONE) {
return ssc->transfer(dev, val);
}
return 0;
}
static void ssi_slave_realize(DeviceState *dev, Error **errp)
{
SSISlave *s = SSI_SLAVE(dev);
SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
if (ssc->transfer_raw == ssi_transfer_raw_default &&
ssc->cs_polarity != SSI_CS_NONE) {
qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
}
ssc->realize(s, errp);
}
static void ssi_slave_class_init(ObjectClass *klass, void *data)
{
SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = ssi_slave_realize;
dc->bus_type = TYPE_SSI_BUS;
if (!ssc->transfer_raw) {
ssc->transfer_raw = ssi_transfer_raw_default;
}
}
static const TypeInfo ssi_slave_info = {
.name = TYPE_SSI_SLAVE,
.parent = TYPE_DEVICE,
.class_init = ssi_slave_class_init,
.class_size = sizeof(SSISlaveClass),
.abstract = true,
};
DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
{
DeviceState *dev = qdev_new(name);
qdev_realize_and_unref(dev, &bus->parent_obj, &error_fatal);
return dev;
}
SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
{
BusState *bus;
bus = qbus_create(TYPE_SSI_BUS, parent, name);
return SSI_BUS(bus);
}
uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
{
BusState *b = BUS(bus);
BusChild *kid;
SSISlaveClass *ssc;
uint32_t r = 0;
QTAILQ_FOREACH(kid, &b->children, sibling) {
SSISlave *slave = SSI_SLAVE(kid->child);
ssc = SSI_SLAVE_GET_CLASS(slave);
r |= ssc->transfer_raw(slave, val);
}
return r;
}
const VMStateDescription vmstate_ssi_slave = {
.name = "SSISlave",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_BOOL(cs, SSISlave),
VMSTATE_END_OF_LIST()
}
};
static void ssi_slave_register_types(void)
{
type_register_static(&ssi_bus_info);
type_register_static(&ssi_slave_info);
}
type_init(ssi_slave_register_types)