dm: test: Add a test for the ram uclass

Add a test to confirm that we can probe this device and get information on
the available RAM.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/ram/sandbox_ram.c b/drivers/ram/sandbox_ram.c
new file mode 100644
index 0000000..06bf3ec
--- /dev/null
+++ b/drivers/ram/sandbox_ram.c
@@ -0,0 +1,38 @@
+/*
+ * 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 <errno.h>
+#include <ram.h>
+#include <asm/test.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int sandbox_get_info(struct udevice *dev, struct ram_info *info)
+{
+	info->base = 0;
+	info->size = gd->ram_size;
+
+	return 0;
+}
+
+static const struct ram_ops sandbox_ram_ops = {
+	.get_info	= sandbox_get_info,
+};
+
+static const struct udevice_id sandbox_ram_ids[] = {
+	{ .compatible = "sandbox,ram" },
+	{ }
+};
+
+U_BOOT_DRIVER(warm_ram_sandbox) = {
+	.name		= "ram_sandbox",
+	.id		= UCLASS_RAM,
+	.of_match	= sandbox_ram_ids,
+	.ops		= &sandbox_ram_ops,
+};