This does a write to every slaves when the I2C bus get a write to address 0. Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com> Reviewed-by: Alistair Francis <alistair.francis@xilinx.com> Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> Tested-By: Hyun Kwon <hyun.kwon@xilinx.com> Message-id: 1465833014-21982-3-git-send-email-fred.konrad@greensocs.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
270 lines
6.2 KiB
C
270 lines
6.2 KiB
C
/*
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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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* This code is licensed under the LGPL.
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*/
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#include "qemu/osdep.h"
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#include "hw/i2c/i2c.h"
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typedef struct I2CNode I2CNode;
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struct I2CNode {
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I2CSlave *elt;
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QLIST_ENTRY(I2CNode) next;
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};
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struct I2CBus
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{
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BusState qbus;
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QLIST_HEAD(, I2CNode) current_devs;
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uint8_t saved_address;
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bool broadcast;
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};
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static Property i2c_props[] = {
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DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
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DEFINE_PROP_END_OF_LIST(),
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};
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#define TYPE_I2C_BUS "i2c-bus"
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#define I2C_BUS(obj) OBJECT_CHECK(I2CBus, (obj), TYPE_I2C_BUS)
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static const TypeInfo i2c_bus_info = {
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.name = TYPE_I2C_BUS,
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.parent = TYPE_BUS,
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.instance_size = sizeof(I2CBus),
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};
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static void i2c_bus_pre_save(void *opaque)
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{
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I2CBus *bus = opaque;
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bus->saved_address = -1;
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if (!QLIST_EMPTY(&bus->current_devs)) {
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if (!bus->broadcast) {
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bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
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}
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}
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}
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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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.pre_save = i2c_bus_pre_save,
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.fields = (VMStateField[]) {
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VMSTATE_UINT8(saved_address, I2CBus),
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VMSTATE_BOOL(broadcast, I2CBus),
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VMSTATE_END_OF_LIST()
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}
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};
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/* Create a new I2C bus. */
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I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
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{
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I2CBus *bus;
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bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
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QLIST_INIT(&bus->current_devs);
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vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
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return bus;
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}
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void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
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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(I2CBus *bus)
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{
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return !QLIST_EMPTY(&bus->current_devs);
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}
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/* Returns non-zero if the address is not valid. */
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/* TODO: Make this handle multiple masters. */
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int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
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{
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BusChild *kid;
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I2CSlaveClass *sc;
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I2CNode *node;
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if (address == 0x00) {
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/*
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* This is a broadcast, the current_devs will be all the devices of the
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* bus.
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*/
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bus->broadcast = true;
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}
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QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
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DeviceState *qdev = kid->child;
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I2CSlave *candidate = I2C_SLAVE(qdev);
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if ((candidate->address == address) || (bus->broadcast)) {
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node = g_malloc(sizeof(struct I2CNode));
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node->elt = candidate;
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QLIST_INSERT_HEAD(&bus->current_devs, node, next);
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if (!bus->broadcast) {
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break;
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}
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}
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}
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if (QLIST_EMPTY(&bus->current_devs)) {
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return 1;
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}
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QLIST_FOREACH(node, &bus->current_devs, next) {
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sc = I2C_SLAVE_GET_CLASS(node->elt);
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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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if (sc->event) {
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sc->event(node->elt, recv ? I2C_START_RECV : I2C_START_SEND);
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}
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}
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return 0;
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}
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void i2c_end_transfer(I2CBus *bus)
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{
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I2CSlaveClass *sc;
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I2CNode *node, *next;
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if (QLIST_EMPTY(&bus->current_devs)) {
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return;
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}
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QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
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sc = I2C_SLAVE_GET_CLASS(node->elt);
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if (sc->event) {
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sc->event(node->elt, I2C_FINISH);
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}
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QLIST_REMOVE(node, next);
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g_free(node);
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}
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bus->broadcast = false;
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}
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int i2c_send(I2CBus *bus, uint8_t data)
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{
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I2CSlaveClass *sc;
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I2CNode *node;
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int ret = 0;
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QLIST_FOREACH(node, &bus->current_devs, next) {
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sc = I2C_SLAVE_GET_CLASS(node->elt);
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if (sc->send) {
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ret = ret || sc->send(node->elt, data);
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} else {
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ret = -1;
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}
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}
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return ret ? -1 : 0;
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}
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int i2c_recv(I2CBus *bus)
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{
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I2CSlaveClass *sc;
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if ((QLIST_EMPTY(&bus->current_devs)) || (bus->broadcast)) {
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return -1;
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}
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sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
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if (sc->recv) {
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return sc->recv(QLIST_FIRST(&bus->current_devs)->elt);
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}
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return -1;
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}
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void i2c_nack(I2CBus *bus)
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{
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I2CSlaveClass *sc;
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I2CNode *node;
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if (QLIST_EMPTY(&bus->current_devs)) {
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return;
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}
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QLIST_FOREACH(node, &bus->current_devs, next) {
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sc = I2C_SLAVE_GET_CLASS(node->elt);
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if (sc->event) {
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sc->event(node->elt, I2C_NACK);
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}
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}
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}
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static int i2c_slave_post_load(void *opaque, int version_id)
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{
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I2CSlave *dev = opaque;
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I2CBus *bus;
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I2CNode *node;
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bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
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if ((bus->saved_address == dev->address) || (bus->broadcast)) {
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node = g_malloc(sizeof(struct I2CNode));
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node->elt = dev;
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QLIST_INSERT_HEAD(&bus->current_devs, node, next);
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}
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return 0;
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}
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const VMStateDescription vmstate_i2c_slave = {
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.name = "I2CSlave",
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.version_id = 1,
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.minimum_version_id = 1,
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.post_load = i2c_slave_post_load,
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.fields = (VMStateField[]) {
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VMSTATE_UINT8(address, I2CSlave),
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VMSTATE_END_OF_LIST()
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}
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};
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static int i2c_slave_qdev_init(DeviceState *dev)
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{
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I2CSlave *s = I2C_SLAVE(dev);
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I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s);
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return sc->init(s);
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}
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DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr)
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{
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DeviceState *dev;
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dev = qdev_create(&bus->qbus, name);
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qdev_prop_set_uint8(dev, "address", addr);
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qdev_init_nofail(dev);
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return dev;
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}
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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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set_bit(DEVICE_CATEGORY_MISC, k->categories);
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k->bus_type = TYPE_I2C_BUS;
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k->props = i2c_props;
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}
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static const 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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.class_init = i2c_slave_class_init,
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};
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static void i2c_slave_register_types(void)
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{
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type_register_static(&i2c_bus_info);
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type_register_static(&i2c_slave_type_info);
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}
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type_init(i2c_slave_register_types)
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