/* * QEMU I2C bus interface. * * Copyright (c) 2007 CodeSourcery. * Written by Paul Brook * * This code is licenced under the LGPL. */#include "hw.h"#include "i2c.h"struct i2c_bus{    i2c_slave *current_dev;    i2c_slave *dev;};/* Create a new I2C bus.  */i2c_bus *i2c_init_bus(void){    i2c_bus *bus;    bus = (i2c_bus *)qemu_mallocz(sizeof(i2c_bus));    return bus;}/* Create a new slave device.  */i2c_slave *i2c_slave_init(i2c_bus *bus, int address, int size){    i2c_slave *dev;    if (size < sizeof(i2c_slave))        hw_error("I2C struct too small");    dev = (i2c_slave *)qemu_mallocz(size);    dev->address = address;    dev->next = bus->dev;    bus->dev = dev;    return dev;}void i2c_set_slave_address(i2c_slave *dev, int 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, int address, int recv){    i2c_slave *dev;    for (dev = bus->dev; dev; dev = dev->next) {        if (dev->address == address)            break;    }    if (!dev)        return 1;    /* If the bus is already busy, assume this is a repeated       start condition.  */    bus->current_dev = dev;    dev->event(dev, recv ? I2C_START_RECV : I2C_START_SEND);    return 0;}void i2c_end_transfer(i2c_bus *bus){    i2c_slave *dev = bus->current_dev;    if (!dev)        return;    dev->event(dev, I2C_FINISH);    bus->current_dev = NULL;}int i2c_send(i2c_bus *bus, uint8_t data){    i2c_slave *dev = bus->current_dev;    if (!dev)        return -1;    return dev->send(dev, data);}int i2c_recv(i2c_bus *bus){    i2c_slave *dev = bus->current_dev;    if (!dev)        return -1;    return dev->recv(dev);}void i2c_nack(i2c_bus *bus){    i2c_slave *dev = bus->current_dev;    if (!dev)        return;    dev->event(dev, I2C_NACK);}void i2c_bus_save(QEMUFile *f, i2c_bus *bus){    qemu_put_byte(f, bus->current_dev ? bus->current_dev->address : 0x00);}void i2c_bus_load(QEMUFile *f, i2c_bus *bus){    i2c_slave *dev;    uint8_t address = qemu_get_byte(f);    if (address) {        for (dev = bus->dev; dev; dev = dev->next)            if (dev->address == address) {                bus->current_dev = dev;                return;            }        fprintf(stderr, "%s: I2C slave with address %02x disappeared\n",                __FUNCTION__, address);    }}void i2c_slave_save(QEMUFile *f, i2c_slave *dev){    qemu_put_byte(f, dev->address);}void i2c_slave_load(QEMUFile *f, i2c_slave *dev){    dev->address = qemu_get_byte(f);}