2007-09-16 23:08:06 +02:00
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/*
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2007-05-23 02:03:59 +02:00
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* QEMU I2C bus interface.
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*
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* Copyright (c) 2007 CodeSourcery.
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* Written by Paul Brook
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*
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2011-06-26 04:21:35 +02:00
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* This code is licensed under the LGPL.
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2007-05-23 02:03:59 +02:00
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*/
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2007-11-17 18:14:51 +01:00
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#include "i2c.h"
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2007-05-23 02:03:59 +02:00
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struct i2c_bus
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{
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2009-05-23 01:05:19 +02:00
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BusState qbus;
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2011-12-05 03:28:27 +01:00
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I2CSlave *current_dev;
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I2CSlave *dev;
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2009-09-29 22:48:26 +02:00
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uint8_t saved_address;
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2007-05-23 02:03:59 +02:00
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};
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2009-06-30 14:12:08 +02:00
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static struct BusInfo i2c_bus_info = {
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.name = "I2C",
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.size = sizeof(i2c_bus),
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2009-07-15 13:43:31 +02:00
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.props = (Property[]) {
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2011-12-05 03:28:27 +01:00
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DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
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2009-08-03 17:35:25 +02:00
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DEFINE_PROP_END_OF_LIST(),
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2009-07-15 13:43:31 +02:00
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}
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2009-06-30 14:12:08 +02:00
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};
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2009-09-29 22:48:27 +02:00
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static void i2c_bus_pre_save(void *opaque)
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2008-07-02 01:16:53 +02:00
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{
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2009-09-29 22:48:27 +02:00
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i2c_bus *bus = opaque;
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2008-07-02 01:16:53 +02:00
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2009-09-29 22:48:27 +02:00
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bus->saved_address = bus->current_dev ? bus->current_dev->address : -1;
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2008-07-02 01:16:53 +02:00
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}
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2009-09-29 22:48:27 +02:00
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static int i2c_bus_post_load(void *opaque, int version_id)
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2008-07-02 01:16:53 +02:00
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{
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2009-09-29 22:48:27 +02:00
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i2c_bus *bus = opaque;
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2008-07-02 01:16:53 +02:00
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/* The bus is loaded before attached devices, so load and save the
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current device id. Devices will check themselves as loaded. */
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bus->current_dev = NULL;
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return 0;
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}
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2009-09-29 22:48:27 +02:00
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static const VMStateDescription vmstate_i2c_bus = {
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.name = "i2c_bus",
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.version_id = 1,
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.minimum_version_id = 1,
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.minimum_version_id_old = 1,
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.pre_save = i2c_bus_pre_save,
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.post_load = i2c_bus_post_load,
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.fields = (VMStateField []) {
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VMSTATE_UINT8(saved_address, i2c_bus),
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VMSTATE_END_OF_LIST()
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}
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};
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2007-05-23 02:03:59 +02:00
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/* Create a new I2C bus. */
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2009-05-23 01:05:19 +02:00
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i2c_bus *i2c_init_bus(DeviceState *parent, const char *name)
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2007-05-23 02:03:59 +02:00
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{
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i2c_bus *bus;
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2009-06-30 14:12:08 +02:00
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bus = FROM_QBUS(i2c_bus, qbus_create(&i2c_bus_info, parent, name));
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2010-06-25 19:09:07 +02:00
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vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
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2007-05-23 02:03:59 +02:00
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return bus;
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}
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2011-12-05 03:28:27 +01:00
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void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
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2007-05-23 02:03:59 +02:00
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{
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dev->address = address;
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}
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/* Return nonzero if bus is busy. */
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int i2c_bus_busy(i2c_bus *bus)
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{
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return bus->current_dev != NULL;
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}
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2007-11-03 01:51:03 +01:00
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/* Returns non-zero if the address is not valid. */
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2007-05-23 02:03:59 +02:00
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/* TODO: Make this handle multiple masters. */
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2009-09-29 22:48:26 +02:00
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int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv)
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2007-05-23 02:03:59 +02:00
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{
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2009-05-23 01:05:19 +02:00
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DeviceState *qdev;
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2011-12-05 03:28:27 +01:00
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I2CSlave *slave = NULL;
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc;
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2007-05-23 02:03:59 +02:00
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2011-09-14 09:28:06 +02:00
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QTAILQ_FOREACH(qdev, &bus->qbus.children, sibling) {
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2011-12-05 03:28:27 +01:00
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I2CSlave *candidate = I2C_SLAVE_FROM_QDEV(qdev);
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2009-06-08 08:27:19 +02:00
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if (candidate->address == address) {
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slave = candidate;
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2007-05-23 02:03:59 +02:00
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break;
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2009-06-08 08:27:19 +02:00
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}
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2007-05-23 02:03:59 +02:00
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}
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2011-12-05 03:39:20 +01:00
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if (!slave) {
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2007-05-23 02:03:59 +02:00
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return 1;
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2011-12-05 03:39:20 +01:00
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}
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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sc = I2C_SLAVE_GET_CLASS(slave);
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2007-05-23 02:03:59 +02:00
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/* If the bus is already busy, assume this is a repeated
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start condition. */
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2009-05-23 01:05:19 +02:00
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bus->current_dev = slave;
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2011-12-05 03:39:20 +01:00
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if (sc->event) {
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sc->event(slave, recv ? I2C_START_RECV : I2C_START_SEND);
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}
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2007-05-23 02:03:59 +02:00
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return 0;
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}
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void i2c_end_transfer(i2c_bus *bus)
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *dev = bus->current_dev;
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc;
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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if (!dev) {
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2007-05-23 02:03:59 +02:00
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return;
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2011-12-05 03:39:20 +01:00
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}
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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sc = I2C_SLAVE_GET_CLASS(dev);
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if (sc->event) {
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sc->event(dev, I2C_FINISH);
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}
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2007-05-23 02:03:59 +02:00
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bus->current_dev = NULL;
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}
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int i2c_send(i2c_bus *bus, uint8_t data)
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *dev = bus->current_dev;
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc;
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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if (!dev) {
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2007-05-23 02:03:59 +02:00
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return -1;
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2011-12-05 03:39:20 +01:00
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}
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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sc = I2C_SLAVE_GET_CLASS(dev);
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if (sc->send) {
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return sc->send(dev, data);
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}
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return -1;
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2007-05-23 02:03:59 +02:00
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}
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int i2c_recv(i2c_bus *bus)
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *dev = bus->current_dev;
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc;
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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if (!dev) {
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2007-05-23 02:03:59 +02:00
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return -1;
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2011-12-05 03:39:20 +01:00
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}
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sc = I2C_SLAVE_GET_CLASS(dev);
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if (sc->recv) {
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return sc->recv(dev);
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}
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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return -1;
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2007-05-23 02:03:59 +02:00
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}
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void i2c_nack(i2c_bus *bus)
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *dev = bus->current_dev;
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc;
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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if (!dev) {
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2007-05-23 02:03:59 +02:00
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return;
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2011-12-05 03:39:20 +01:00
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}
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2007-05-23 02:03:59 +02:00
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2011-12-05 03:39:20 +01:00
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sc = I2C_SLAVE_GET_CLASS(dev);
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if (sc->event) {
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sc->event(dev, I2C_NACK);
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}
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2007-05-23 02:03:59 +02:00
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}
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2009-09-29 22:48:28 +02:00
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static int i2c_slave_post_load(void *opaque, int version_id)
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2007-05-24 20:50:09 +02:00
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *dev = opaque;
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2009-05-14 23:35:08 +02:00
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i2c_bus *bus;
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2009-05-23 01:05:19 +02:00
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bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev));
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2009-05-14 23:35:08 +02:00
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if (bus->saved_address == dev->address) {
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bus->current_dev = dev;
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}
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2009-09-29 22:48:28 +02:00
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return 0;
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}
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2009-09-29 22:48:30 +02:00
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const VMStateDescription vmstate_i2c_slave = {
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2011-12-05 03:28:27 +01:00
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.name = "I2CSlave",
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2009-09-29 22:48:28 +02:00
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.version_id = 1,
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.minimum_version_id = 1,
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.minimum_version_id_old = 1,
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.post_load = i2c_slave_post_load,
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.fields = (VMStateField []) {
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2011-12-05 03:28:27 +01:00
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VMSTATE_UINT8(address, I2CSlave),
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2009-09-29 22:48:28 +02:00
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VMSTATE_END_OF_LIST()
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}
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};
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2009-08-14 10:36:05 +02:00
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static int i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base)
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2009-05-14 23:35:08 +02:00
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{
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2011-12-05 03:28:27 +01:00
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I2CSlave *s = I2C_SLAVE_FROM_QDEV(dev);
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2011-12-05 03:39:20 +01:00
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I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s);
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2009-05-14 23:35:08 +02:00
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2011-12-05 03:39:20 +01:00
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return sc->init(s);
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}
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2009-05-14 23:35:08 +02:00
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2009-09-29 22:48:26 +02:00
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DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr)
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2009-05-14 23:35:08 +02:00
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{
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DeviceState *dev;
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2009-05-23 01:05:19 +02:00
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dev = qdev_create(&bus->qbus, name);
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2009-09-29 22:48:26 +02:00
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qdev_prop_set_uint8(dev, "address", addr);
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2009-10-07 01:15:58 +02:00
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qdev_init_nofail(dev);
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2009-05-14 23:35:08 +02:00
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return dev;
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2007-05-24 20:50:09 +02:00
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}
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2011-12-05 03:39:20 +01:00
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2011-12-08 04:34:16 +01:00
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static void i2c_slave_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *k = DEVICE_CLASS(klass);
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k->init = i2c_slave_qdev_init;
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k->bus_info = &i2c_bus_info;
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}
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2011-12-05 03:39:20 +01:00
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static TypeInfo i2c_slave_type_info = {
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.name = TYPE_I2C_SLAVE,
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.parent = TYPE_DEVICE,
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.instance_size = sizeof(I2CSlave),
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.abstract = true,
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.class_size = sizeof(I2CSlaveClass),
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2011-12-08 04:34:16 +01:00
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.class_init = i2c_slave_class_init,
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2011-12-05 03:39:20 +01:00
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};
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static void i2c_slave_register_devices(void)
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{
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type_register_static(&i2c_slave_type_info);
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}
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device_init(i2c_slave_register_devices);
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