qemu/hw/i2c.c
Anthony Liguori 0866aca1de qbus: Make child devices links
Make qbus children show up as link<> properties.  There is no stable
addressing for qbus children so we use an unstable naming convention.

This is okay in QOM though because the composition name is expected to
be what's stable.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2012-06-18 15:14:38 +02:00

247 lines
5.2 KiB
C

/*
* QEMU I2C bus interface.
*
* Copyright (c) 2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the LGPL.
*/
#include "i2c.h"
struct i2c_bus
{
BusState qbus;
I2CSlave *current_dev;
I2CSlave *dev;
uint8_t saved_address;
};
static Property i2c_props[] = {
DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
DEFINE_PROP_END_OF_LIST(),
};
#define TYPE_I2C_BUS "i2c-bus"
#define I2C_BUS(obj) OBJECT_CHECK(i2c_bus, (obj), TYPE_I2C_BUS)
static const TypeInfo i2c_bus_info = {
.name = TYPE_I2C_BUS,
.parent = TYPE_BUS,
.instance_size = sizeof(i2c_bus),
};
static void i2c_bus_pre_save(void *opaque)
{
i2c_bus *bus = opaque;
bus->saved_address = bus->current_dev ? bus->current_dev->address : -1;
}
static int i2c_bus_post_load(void *opaque, int version_id)
{
i2c_bus *bus = opaque;
/* The bus is loaded before attached devices, so load and save the
current device id. Devices will check themselves as loaded. */
bus->current_dev = NULL;
return 0;
}
static const VMStateDescription vmstate_i2c_bus = {
.name = "i2c_bus",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.pre_save = i2c_bus_pre_save,
.post_load = i2c_bus_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT8(saved_address, i2c_bus),
VMSTATE_END_OF_LIST()
}
};
/* Create a new I2C bus. */
i2c_bus *i2c_init_bus(DeviceState *parent, const char *name)
{
i2c_bus *bus;
bus = FROM_QBUS(i2c_bus, qbus_create(TYPE_I2C_BUS, parent, name));
vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
return bus;
}
void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
{
dev->address = address;
}
/* Return nonzero if bus is busy. */
int i2c_bus_busy(i2c_bus *bus)
{
return bus->current_dev != NULL;
}
/* Returns non-zero if the address is not valid. */
/* TODO: Make this handle multiple masters. */
int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv)
{
BusChild *kid;
I2CSlave *slave = NULL;
I2CSlaveClass *sc;
QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
DeviceState *qdev = kid->child;
I2CSlave *candidate = I2C_SLAVE_FROM_QDEV(qdev);
if (candidate->address == address) {
slave = candidate;
break;
}
}
if (!slave) {
return 1;
}
sc = I2C_SLAVE_GET_CLASS(slave);
/* If the bus is already busy, assume this is a repeated
start condition. */
bus->current_dev = slave;
if (sc->event) {
sc->event(slave, recv ? I2C_START_RECV : I2C_START_SEND);
}
return 0;
}
void i2c_end_transfer(i2c_bus *bus)
{
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
if (!dev) {
return;
}
sc = I2C_SLAVE_GET_CLASS(dev);
if (sc->event) {
sc->event(dev, I2C_FINISH);
}
bus->current_dev = NULL;
}
int i2c_send(i2c_bus *bus, uint8_t data)
{
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
if (!dev) {
return -1;
}
sc = I2C_SLAVE_GET_CLASS(dev);
if (sc->send) {
return sc->send(dev, data);
}
return -1;
}
int i2c_recv(i2c_bus *bus)
{
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
if (!dev) {
return -1;
}
sc = I2C_SLAVE_GET_CLASS(dev);
if (sc->recv) {
return sc->recv(dev);
}
return -1;
}
void i2c_nack(i2c_bus *bus)
{
I2CSlave *dev = bus->current_dev;
I2CSlaveClass *sc;
if (!dev) {
return;
}
sc = I2C_SLAVE_GET_CLASS(dev);
if (sc->event) {
sc->event(dev, I2C_NACK);
}
}
static int i2c_slave_post_load(void *opaque, int version_id)
{
I2CSlave *dev = opaque;
i2c_bus *bus;
bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev));
if (bus->saved_address == dev->address) {
bus->current_dev = dev;
}
return 0;
}
const VMStateDescription vmstate_i2c_slave = {
.name = "I2CSlave",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.post_load = i2c_slave_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT8(address, I2CSlave),
VMSTATE_END_OF_LIST()
}
};
static int i2c_slave_qdev_init(DeviceState *dev)
{
I2CSlave *s = I2C_SLAVE_FROM_QDEV(dev);
I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s);
return sc->init(s);
}
DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr)
{
DeviceState *dev;
dev = qdev_create(&bus->qbus, name);
qdev_prop_set_uint8(dev, "address", addr);
qdev_init_nofail(dev);
return dev;
}
static void i2c_slave_class_init(ObjectClass *klass, void *data)
{
DeviceClass *k = DEVICE_CLASS(klass);
k->init = i2c_slave_qdev_init;
k->bus_type = TYPE_I2C_BUS;
k->props = i2c_props;
}
static TypeInfo i2c_slave_type_info = {
.name = TYPE_I2C_SLAVE,
.parent = TYPE_DEVICE,
.instance_size = sizeof(I2CSlave),
.abstract = true,
.class_size = sizeof(I2CSlaveClass),
.class_init = i2c_slave_class_init,
};
static void i2c_slave_register_types(void)
{
type_register_static(&i2c_bus_info);
type_register_static(&i2c_slave_type_info);
}
type_init(i2c_slave_register_types)