x86: i2c: Add a stub driver for Intel I2C/SMbus

This is used on most Intel platforms. We don't have a driver for it yet, but
add a stub to handle the init. For now this targets ivybridge so we may want
to add a device tree binding and generalise it when other platforms are
supported.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/i2c/intel_i2c.c b/drivers/i2c/intel_i2c.c
new file mode 100644
index 0000000..1082d1a
--- /dev/null
+++ b/drivers/i2c/intel_i2c.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <asm/io.h>
+
+int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+{
+	return -ENOSYS;
+}
+
+int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr, uint chip_flags)
+{
+	return -ENOSYS;
+}
+
+int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
+{
+	return 0;
+}
+
+static int intel_i2c_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+static const struct dm_i2c_ops intel_i2c_ops = {
+	.xfer		= intel_i2c_xfer,
+	.probe_chip	= intel_i2c_probe_chip,
+	.set_bus_speed	= intel_i2c_set_bus_speed,
+};
+
+static const struct udevice_id intel_i2c_ids[] = {
+	{ .compatible = "intel,ich-i2c" },
+	{ }
+};
+
+U_BOOT_DRIVER(intel_i2c) = {
+	.name	= "i2c_intel",
+	.id	= UCLASS_I2C,
+	.of_match = intel_i2c_ids,
+	.per_child_auto_alloc_size = sizeof(struct dm_i2c_chip),
+	.ops	= &intel_i2c_ops,
+	.probe	= intel_i2c_probe,
+};