Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 218 insertions, 0 deletions

diff --git a/hw/gpio/max7310.c b/hw/gpio/max7310.c
new file mode 100644
index 000000000..db6b5e3d7
--- /dev/null
+++ b/hw/gpio/max7310.c
@@ -0,0 +1,218 @@
+/*
+ * MAX7310 8-port GPIO expansion chip.
+ *
+ * Copyright (c) 2006 Openedhand Ltd.
+ * Written by Andrzej Zaborowski <balrog@zabor.org>
+ *
+ * This file is licensed under GNU GPL.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/i2c/i2c.h"
+#include "hw/irq.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qom/object.h"
+
+#define TYPE_MAX7310 "max7310"
+OBJECT_DECLARE_SIMPLE_TYPE(MAX7310State, MAX7310)
+
+struct MAX7310State {
+    I2CSlave parent_obj;
+
+    int i2c_command_byte;
+    int len;
+
+    uint8_t level;
+    uint8_t direction;
+    uint8_t polarity;
+    uint8_t status;
+    uint8_t command;
+    qemu_irq handler[8];
+    qemu_irq *gpio_in;
+};
+
+static void max7310_reset(DeviceState *dev)
+{
+    MAX7310State *s = MAX7310(dev);
+
+    s->level &= s->direction;
+    s->direction = 0xff;
+    s->polarity = 0xf0;
+    s->status = 0x01;
+    s->command = 0x00;
+}
+
+static uint8_t max7310_rx(I2CSlave *i2c)
+{
+    MAX7310State *s = MAX7310(i2c);
+
+    switch (s->command) {
+    case 0x00:	/* Input port */
+        return s->level ^ s->polarity;
+
+    case 0x01:	/* Output port */
+        return s->level & ~s->direction;
+
+    case 0x02:	/* Polarity inversion */
+        return s->polarity;
+
+    case 0x03:	/* Configuration */
+        return s->direction;
+
+    case 0x04:	/* Timeout */
+        return s->status;
+
+    case 0xff:	/* Reserved */
+        return 0xff;
+
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
+                      __func__, s->command);
+        break;
+    }
+    return 0xff;
+}
+
+static int max7310_tx(I2CSlave *i2c, uint8_t data)
+{
+    MAX7310State *s = MAX7310(i2c);
+    uint8_t diff;
+    int line;
+
+    if (s->len ++ > 1) {
+#ifdef VERBOSE
+        printf("%s: message too long (%i bytes)\n", __func__, s->len);
+#endif
+        return 1;
+    }
+
+    if (s->i2c_command_byte) {
+        s->command = data;
+        s->i2c_command_byte = 0;
+        return 0;
+    }
+
+    switch (s->command) {
+    case 0x01:	/* Output port */
+        for (diff = (data ^ s->level) & ~s->direction; diff;
+                        diff &= ~(1 << line)) {
+            line = ctz32(diff);
+            if (s->handler[line])
+                qemu_set_irq(s->handler[line], (data >> line) & 1);
+        }
+        s->level = (s->level & s->direction) | (data & ~s->direction);
+        break;
+
+    case 0x02:	/* Polarity inversion */
+        s->polarity = data;
+        break;
+
+    case 0x03:	/* Configuration */
+        s->level &= ~(s->direction ^ data);
+        s->direction = data;
+        break;
+
+    case 0x04:	/* Timeout */
+        s->status = data;
+        break;
+
+    case 0x00:	/* Input port - ignore writes */
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: Unsupported register 0x02%" PRIx8 "\n",
+                      __func__, s->command);
+        return 1;
+    }
+
+    return 0;
+}
+
+static int max7310_event(I2CSlave *i2c, enum i2c_event event)
+{
+    MAX7310State *s = MAX7310(i2c);
+    s->len = 0;
+
+    switch (event) {
+    case I2C_START_SEND:
+        s->i2c_command_byte = 1;
+        break;
+    case I2C_FINISH:
+#ifdef VERBOSE
+        if (s->len == 1)
+            printf("%s: message too short (%i bytes)\n", __func__, s->len);
+#endif
+        break;
+    default:
+        break;
+    }
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_max7310 = {
+    .name = "max7310",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_INT32(i2c_command_byte, MAX7310State),
+        VMSTATE_INT32(len, MAX7310State),
+        VMSTATE_UINT8(level, MAX7310State),
+        VMSTATE_UINT8(direction, MAX7310State),
+        VMSTATE_UINT8(polarity, MAX7310State),
+        VMSTATE_UINT8(status, MAX7310State),
+        VMSTATE_UINT8(command, MAX7310State),
+        VMSTATE_I2C_SLAVE(parent_obj, MAX7310State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void max7310_gpio_set(void *opaque, int line, int level)
+{
+    MAX7310State *s = (MAX7310State *) opaque;
+    assert(line >= 0 && line < ARRAY_SIZE(s->handler));
+
+    if (level)
+        s->level |= s->direction & (1 << line);
+    else
+        s->level &= ~(s->direction & (1 << line));
+}
+
+/* MAX7310 is SMBus-compatible (can be used with only SMBus protocols),
+ * but also accepts sequences that are not SMBus so return an I2C device.  */
+static void max7310_realize(DeviceState *dev, Error **errp)
+{
+    I2CSlave *i2c = I2C_SLAVE(dev);
+    MAX7310State *s = MAX7310(dev);
+
+    qdev_init_gpio_in(&i2c->qdev, max7310_gpio_set, 8);
+    qdev_init_gpio_out(&i2c->qdev, s->handler, 8);
+}
+
+static void max7310_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
+
+    dc->realize = max7310_realize;
+    k->event = max7310_event;
+    k->recv = max7310_rx;
+    k->send = max7310_tx;
+    dc->reset = max7310_reset;
+    dc->vmsd = &vmstate_max7310;
+}
+
+static const TypeInfo max7310_info = {
+    .name          = TYPE_MAX7310,
+    .parent        = TYPE_I2C_SLAVE,
+    .instance_size = sizeof(MAX7310State),
+    .class_init    = max7310_class_init,
+};
+
+static void max7310_register_types(void)
+{
+    type_register_static(&max7310_info);
+}
+
+type_init(max7310_register_types)