test: Add tests for CPU uclass

Add a sandbox CPU driver, and some tests for the CPU uclass.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile
index db515f6..980c68f 100644
--- a/drivers/cpu/Makefile
+++ b/drivers/cpu/Makefile
@@ -7,3 +7,4 @@
 obj-$(CONFIG_CPU) += cpu-uclass.o
 
 obj-$(CONFIG_ARCH_BMIPS) += bmips_cpu.o
+obj-$(CONFIG_SANDBOX) += cpu_sandbox.o
diff --git a/drivers/cpu/cpu_sandbox.c b/drivers/cpu/cpu_sandbox.c
new file mode 100644
index 0000000..ff87e8a
--- /dev/null
+++ b/drivers/cpu/cpu_sandbox.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <cpu.h>
+
+int cpu_sandbox_get_desc(struct udevice *dev, char *buf, int size)
+{
+	snprintf(buf, size, "LEG Inc. SuperMegaUltraTurbo CPU No. 1");
+
+	return 0;
+}
+
+int cpu_sandbox_get_info(struct udevice *dev, struct cpu_info *info)
+{
+	info->cpu_freq = 42 * 42 * 42 * 42 * 42;
+	info->features = 0x42424242;
+
+	return 0;
+}
+
+int cpu_sandbox_get_count(struct udevice *dev)
+{
+	return 42;
+}
+
+int cpu_sandbox_get_vendor(struct udevice *dev, char *buf, int size)
+{
+	snprintf(buf, size, "Languid Example Garbage Inc.");
+
+	return 0;
+}
+
+static const struct cpu_ops cpu_sandbox_ops = {
+	.get_desc = cpu_sandbox_get_desc,
+	.get_info = cpu_sandbox_get_info,
+	.get_count = cpu_sandbox_get_count,
+	.get_vendor = cpu_sandbox_get_vendor,
+};
+
+int cpu_sandbox_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+static const struct udevice_id cpu_sandbox_ids[] = {
+	{ .compatible = "sandbox,cpu_sandbox" },
+	{ }
+};
+
+U_BOOT_DRIVER(cpu_sandbox) = {
+	.name           = "cpu_sandbox",
+	.id             = UCLASS_CPU,
+	.ops		= &cpu_sandbox_ops,
+	.of_match       = cpu_sandbox_ids,
+	.probe          = cpu_sandbox_probe,
+};