From 68396ea9c0fe4f75ce30b1eba2c44c43c13344bb Mon Sep 17 00:00:00 2001
From: Robert Mustacchi <rm@joyent.com>
Date: Fri, 24 Jun 2011 13:49:54 -0700
Subject: Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from
 qemu-kvm

---
 hw/i2c.c | 196 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 196 insertions(+)
 create mode 100644 hw/i2c.c

(limited to 'hw/i2c.c')

diff --git a/hw/i2c.c b/hw/i2c.c
new file mode 100644
index 0000000..f80d12d
--- /dev/null
+++ b/hw/i2c.c
@@ -0,0 +1,196 @@
+/*
+ * QEMU I2C bus interface.
+ *
+ * Copyright (c) 2007 CodeSourcery.
+ * Written by Paul Brook
+ *
+ * This code is licenced under the LGPL.
+ */
+
+#include "i2c.h"
+
+struct i2c_bus
+{
+    BusState qbus;
+    i2c_slave *current_dev;
+    i2c_slave *dev;
+    uint8_t saved_address;
+};
+
+static struct BusInfo i2c_bus_info = {
+    .name = "I2C",
+    .size = sizeof(i2c_bus),
+    .props = (Property[]) {
+        DEFINE_PROP_UINT8("address", struct i2c_slave, address, 0),
+        DEFINE_PROP_END_OF_LIST(),
+    }
+};
+
+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(&i2c_bus_info, parent, name));
+    vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
+    return bus;
+}
+
+void i2c_set_slave_address(i2c_slave *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)
+{
+    DeviceState *qdev;
+    i2c_slave *slave = NULL;
+
+    QLIST_FOREACH(qdev, &bus->qbus.children, sibling) {
+        i2c_slave *candidate = I2C_SLAVE_FROM_QDEV(qdev);
+        if (candidate->address == address) {
+            slave = candidate;
+            break;
+        }
+    }
+
+    if (!slave)
+        return 1;
+
+    /* If the bus is already busy, assume this is a repeated
+       start condition.  */
+    bus->current_dev = slave;
+    slave->info->event(slave, 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->info->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->info->send(dev, data);
+}
+
+int i2c_recv(i2c_bus *bus)
+{
+    i2c_slave *dev = bus->current_dev;
+
+    if (!dev)
+        return -1;
+
+    return dev->info->recv(dev);
+}
+
+void i2c_nack(i2c_bus *bus)
+{
+    i2c_slave *dev = bus->current_dev;
+
+    if (!dev)
+        return;
+
+    dev->info->event(dev, I2C_NACK);
+}
+
+static int i2c_slave_post_load(void *opaque, int version_id)
+{
+    i2c_slave *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 = "i2c_slave",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .post_load = i2c_slave_post_load,
+    .fields      = (VMStateField []) {
+        VMSTATE_UINT8(address, i2c_slave),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static int i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base)
+{
+    I2CSlaveInfo *info = container_of(base, I2CSlaveInfo, qdev);
+    i2c_slave *s = I2C_SLAVE_FROM_QDEV(dev);
+
+    s->info = info;
+
+    return info->init(s);
+}
+
+void i2c_register_slave(I2CSlaveInfo *info)
+{
+    assert(info->qdev.size >= sizeof(i2c_slave));
+    info->qdev.init = i2c_slave_qdev_init;
+    info->qdev.bus_info = &i2c_bus_info;
+    qdev_register(&info->qdev);
+}
+
+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;
+}
-- 
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