dm: Add a demonstration/example driver

As an example of how to write a uclass and a driver, provide a demo version
of each, accessible through the 'demo' command.

To use these with driver model, define CONFIG_CMD_DEMO and CONFIG_DM_DEMO.

The two demo drivers are enabled with CONFIG_DM_DEMO_SIMPLE and
CONFIG_DM_DEMO_SHAPE.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: Viktor Křivák <viktor.krivak@gmail.com>
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>
diff --git a/drivers/demo/demo-pdata.c b/drivers/demo/demo-pdata.c
new file mode 100644
index 0000000..e92841d
--- /dev/null
+++ b/drivers/demo/demo-pdata.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm-demo.h>
+
+static const struct dm_demo_pdata red_square = {
+	.colour = "red",
+	.sides = 4.
+};
+static const struct dm_demo_pdata green_triangle = {
+	.colour = "green",
+	.sides = 3.
+};
+static const struct dm_demo_pdata yellow_hexagon = {
+	.colour = "yellow",
+	.sides = 6.
+};
+
+U_BOOT_DEVICE(demo0) = {
+	.name = "demo_shape_drv",
+	.platdata = &red_square,
+};
+
+U_BOOT_DEVICE(demo1) = {
+	.name = "demo_simple_drv",
+	.platdata = &red_square,
+};
+
+U_BOOT_DEVICE(demo2) = {
+	.name = "demo_shape_drv",
+	.platdata = &green_triangle,
+};
+
+U_BOOT_DEVICE(demo3) = {
+	.name = "demo_simple_drv",
+	.platdata = &yellow_hexagon,
+};
+
+U_BOOT_DEVICE(demo4) = {
+	.name = "demo_shape_drv",
+	.platdata = &yellow_hexagon,
+};