Patchwork [U-Boot,v3,11/16] dm: Add a demonstration/example driver

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Submitter Simon Glass
Date June 19, 2013, 3:52 a.m.
Message ID <1371613960-28678-12-git-send-email-sjg@chromium.org>
Download mbox | patch
Permalink /patch/252481/
State Superseded
Delegated to: Tom Rini
Headers show

Comments

Simon Glass - June 19, 2013, 3:52 a.m.
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>
---
Changes in v3:
- Fix up demo command help
- Update demo driver to use device tree

Changes in v2: None

 Makefile                   |   1 +
 common/Makefile            |   1 +
 common/cmd_demo.c          | 115 ++++++++++++++++++++++++++++++++++++
 drivers/demo/Makefile      |  44 ++++++++++++++
 drivers/demo/demo-pdata.c  |  60 +++++++++++++++++++
 drivers/demo/demo-shape.c  | 143 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/demo/demo-simple.c |  61 +++++++++++++++++++
 drivers/demo/demo-uclass.c |  73 +++++++++++++++++++++++
 include/configs/sandbox.h  |   4 ++
 include/dm-demo.h          |  49 ++++++++++++++++
 10 files changed, 551 insertions(+)
 create mode 100644 common/cmd_demo.c
 create mode 100644 drivers/demo/Makefile
 create mode 100644 drivers/demo/demo-pdata.c
 create mode 100644 drivers/demo/demo-shape.c
 create mode 100644 drivers/demo/demo-simple.c
 create mode 100644 drivers/demo/demo-uclass.c
 create mode 100644 include/dm-demo.h
Marek Vasut - June 28, 2013, 9:46 p.m.
Dear Simon Glass,

> 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>
> ---
> Changes in v3:
> - Fix up demo command help
> - Update demo driver to use device tree
> 
> Changes in v2: None

[...]

> +U_BOOT_DEVICE(demo4) = {
> +	.name = "demo_shape_drv",
> +	.platform_data = &yellow_hexagon,
> +};

So this is static instantiation of the drivers?

[...]

> +U_BOOT_DRIVER(demo_simple_drv) = {
> +	.name	= "demo_simple_drv",
> +	.of_match = demo_shape_id,
> +	.id	= UCLASS_DEMO,
> +	.probe	= demo_shape_probe,
> +	.ops	= &simple_ops,
> +	.ops	= &simple_ops,

This .ops is here twice ;-)

> +	.platform_data_auto_alloc_size = sizeof(struct dm_demo_pdata),
> +};

[...]

Best regards,
Marek Vasut
Simon Glass - Oct. 18, 2013, 7:44 p.m.
Hi Marek,

On Fri, Jun 28, 2013 at 3:46 PM, Marek Vasut <marex@denx.de> wrote:

> Dear Simon Glass,
>
> > 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>
> > ---
> > Changes in v3:
> > - Fix up demo command help
> > - Update demo driver to use device tree
> >
> > Changes in v2: None
>
> [...]
>
> > +U_BOOT_DEVICE(demo4) = {
> > +     .name = "demo_shape_drv",
> > +     .platform_data = &yellow_hexagon,
> > +};
>
> So this is static instantiation of the drivers?
>

Yes, it is possible to set up a device either with statically-linked
platform_data (as here) or with device tree.


>
> [...]
>
> > +U_BOOT_DRIVER(demo_simple_drv) = {
> > +     .name   = "demo_simple_drv",
> > +     .of_match = demo_shape_id,
> > +     .id     = UCLASS_DEMO,
> > +     .probe  = demo_shape_probe,
> > +     .ops    = &simple_ops,
> > +     .ops    = &simple_ops,
>
> This .ops is here twice ;-)
>

Fixed.



>
> > +     .platform_data_auto_alloc_size = sizeof(struct dm_demo_pdata),
> > +};
>
> [...]
>
>
>
Regards,
Simon

Patch

diff --git a/Makefile b/Makefile
index 0655c9c..1654ec3 100644
--- a/Makefile
+++ b/Makefile
@@ -338,6 +338,7 @@  LIBS-y += post/libpost.o
 LIBS-y += test/libtest.o
 LIBS-y += test/dm/libtestdm.o
 
+LIBS-$(CONFIG_DM_DEMO) += drivers/demo/libdemo.o
 LIBS-$(CONFIG_DM) += common/dm/libdm.o
 
 ifneq ($(CONFIG_AM33XX)$(CONFIG_OMAP34XX)$(CONFIG_OMAP44XX)$(CONFIG_OMAP54XX)$(CONFIG_TI814X),)
diff --git a/common/Makefile b/common/Makefile
index 3ba4316..99921ca 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -85,6 +85,7 @@  COBJS-$(CONFIG_CMD_CONSOLE) += cmd_console.o
 COBJS-$(CONFIG_CMD_CPLBINFO) += cmd_cplbinfo.o
 COBJS-$(CONFIG_DATAFLASH_MMC_SELECT) += cmd_dataflash_mmc_mux.o
 COBJS-$(CONFIG_CMD_DATE) += cmd_date.o
+COBJS-$(CONFIG_CMD_DEMO) += cmd_demo.o
 COBJS-$(CONFIG_CMD_SOUND) += cmd_sound.o
 ifdef CONFIG_4xx
 COBJS-$(CONFIG_CMD_SETGETDCR) += cmd_dcr.o
diff --git a/common/cmd_demo.c b/common/cmd_demo.c
new file mode 100644
index 0000000..6ec91f8
--- /dev/null
+++ b/common/cmd_demo.c
@@ -0,0 +1,115 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * (C) Copyright 2012
+ * Pavel Herrmann <morpheus.ibis@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <dm-demo.h>
+#include <asm/io.h>
+
+struct device *demo_dev;
+
+static int do_demo_hello(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char * const argv[])
+{
+	int ch = 0;
+
+	if (argc)
+		ch = *argv[0];
+
+	return demo_hello(demo_dev, ch);
+}
+
+static int do_demo_status(cmd_tbl_t *cmdtp, int flag, int argc,
+			  char * const argv[])
+{
+	int status;
+	int ret;
+
+	ret = demo_status(demo_dev, &status);
+	if (ret)
+		return ret;
+
+	printf("Status: %d\n", status);
+
+	return 0;
+}
+
+int do_demo_list(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct device *dev;
+	int i, ret;
+
+	puts("Demo uclass entries:\n");
+
+	for (i = 0, ret = uclass_first_device(UCLASS_DEMO, &dev);
+	     dev;
+	     ret = uclass_next_device(&dev)) {
+		printf("entry %d - instance %08x, ops %08x, platform_data %08x\n",
+		       i++, map_to_sysmem(dev),
+		       map_to_sysmem(dev->driver->ops),
+		       map_to_sysmem(dev->platform_data));
+	}
+
+	return cmd_process_error(cmdtp, ret);
+}
+
+static cmd_tbl_t demo_commands[] = {
+	U_BOOT_CMD_MKENT(list, 0, 1, do_demo_list, "", ""),
+	U_BOOT_CMD_MKENT(hello, 2, 1, do_demo_hello, "", ""),
+	U_BOOT_CMD_MKENT(status, 1, 1, do_demo_status, "", ""),
+};
+
+static int do_demo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	cmd_tbl_t *demo_cmd;
+	int devnum = 0;
+	int ret;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+	demo_cmd = find_cmd_tbl(argv[1], demo_commands,
+				ARRAY_SIZE(demo_commands));
+	argc -= 2;
+	argv += 2;
+	if (!demo_cmd || argc > demo_cmd->maxargs)
+		return CMD_RET_USAGE;
+
+	if (argc) {
+		devnum = simple_strtoul(argv[0], NULL, 10);
+		ret = uclass_get_device(UCLASS_DEMO, devnum, &demo_dev);
+		if (ret)
+			return cmd_process_error(cmdtp, ret);
+		argc--;
+		argv++;
+	}
+
+	ret = demo_cmd->cmd(demo_cmd, flag, argc, argv);
+
+	return cmd_process_error(demo_cmd, ret);
+}
+
+U_BOOT_CMD(
+	demo,   4,      1,      do_demo,
+	"Driver model (dm) demo operations",
+	"list                     List available demo devices\n"
+	"demo hello <num> [<char>]     Say hello\n"
+	"demo status <num>             Get demo device status"
+);
diff --git a/drivers/demo/Makefile b/drivers/demo/Makefile
new file mode 100644
index 0000000..5267659
--- /dev/null
+++ b/drivers/demo/Makefile
@@ -0,0 +1,44 @@ 
+#
+# Copyright (c) 2013 Google, Inc
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	:= $(obj)libdemo.o
+
+COBJS-$(CONFIG_DM_DEMO) += demo-uclass.o demo-pdata.o
+COBJS-$(CONFIG_DM_DEMO_SIMPLE) += demo-simple.o
+COBJS-$(CONFIG_DM_DEMO_SHAPE) += demo-shape.o
+
+COBJS	:= $(COBJS-y)
+SRCS	:= $(COBJS:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS))
+
+all:	$(LIB)
+
+$(LIB):	$(obj).depend $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/drivers/demo/demo-pdata.c b/drivers/demo/demo-pdata.c
new file mode 100644
index 0000000..c04b26e
--- /dev/null
+++ b/drivers/demo/demo-pdata.c
@@ -0,0 +1,60 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#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",
+	.platform_data = &red_square,
+};
+
+U_BOOT_DEVICE(demo1) = {
+	.name = "demo_simple_drv",
+	.platform_data = &red_square,
+};
+
+U_BOOT_DEVICE(demo2) = {
+	.name = "demo_shape_drv",
+	.platform_data = &green_triangle,
+};
+
+U_BOOT_DEVICE(demo3) = {
+	.name = "demo_simple_drv",
+	.platform_data = &yellow_hexagon,
+};
+
+U_BOOT_DEVICE(demo4) = {
+	.name = "demo_shape_drv",
+	.platform_data = &yellow_hexagon,
+};
diff --git a/drivers/demo/demo-shape.c b/drivers/demo/demo-shape.c
new file mode 100644
index 0000000..918115a
--- /dev/null
+++ b/drivers/demo/demo-shape.c
@@ -0,0 +1,143 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <dm-demo.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Shape size */
+#define WIDTH	8
+#define HEIGHT	6
+
+struct shape_data {
+	int num_chars;	/* Number of non-space characters output so far */
+};
+
+/* Crazy little function to draw shapes on the console */
+static int shape_hello(struct device *dev, int ch)
+{
+	const struct dm_demo_pdata *pdata = dev->platform_data;
+	struct shape_data *data = dev->priv;
+	static const struct shape {
+		int start;
+		int end;
+		int dstart;
+		int dend;
+	} shapes[3] = {
+		{ 0, 1, 0, 1 },
+		{ 0, WIDTH, 0, 0 },
+		{ HEIGHT / 2 - 1, WIDTH - HEIGHT / 2 + 1, -1, 1},
+	};
+	struct shape shape;
+	unsigned int index;
+	int line, pos, inside;
+	const char *colour = pdata->colour;
+	int first = 0;
+
+	if (!ch)
+		ch = pdata->default_char;
+	if (!ch)
+		ch = '@';
+
+	index = (pdata->sides / 2) - 1;
+	if (index >= ARRAY_SIZE(shapes))
+		return -EIO;
+	shape = shapes[index];
+
+	for (line = 0; line < HEIGHT; line++) {
+		first = 1;
+		for (pos = 0; pos < WIDTH; pos++) {
+			inside = pos >= shape.start && pos < shape.end;
+			if (inside) {
+				putc(first ? *colour++ : ch);
+				data->num_chars++;
+				first = 0;
+				if (!*colour)
+					colour = pdata->colour;
+			} else {
+				putc(' ');
+			}
+		}
+		putc('\n');
+		shape.start += shape.dstart;
+		shape.end += shape.dend;
+		if (shape.start < 0) {
+			shape.dstart = -shape.dstart;
+			shape.dend = -shape.dend;
+			shape.start += shape.dstart;
+			shape.end += shape.dend;
+		}
+	}
+
+	return 0;
+}
+
+static int shape_status(struct device *dev, int *status)
+{
+	struct shape_data *data = dev->priv;
+
+	*status = data->num_chars;
+	return 0;
+}
+
+static const struct demo_ops simple_ops = {
+	.hello = shape_hello,
+	.status = shape_status,
+};
+
+static int demo_shape_probe(struct device *dev)
+{
+	struct dm_demo_pdata *pdata = dev->platform_data;
+	int ret;
+
+	if (dev->of_offset < 0)
+		return 0;
+
+	/* Parse the data that is common with all demo devices */
+	ret = demo_parse_dt(dev);
+	if (ret)
+		return ret;
+
+	/* Parse the data that only we need */
+	pdata->default_char = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+					     "character", '@');
+
+	return 0;
+}
+
+static const struct device_id demo_shape_id[] = {
+	{ "demo-shape", 0 },
+	{ },
+};
+
+U_BOOT_DRIVER(demo_shape_drv) = {
+	.name	= "demo_shape_drv",
+	.of_match = demo_shape_id,
+	.id	= UCLASS_DEMO,
+	.probe	= demo_shape_probe,
+	.ops	= &simple_ops,
+	.priv_auto_alloc_size = sizeof(struct shape_data),
+	.platform_data_auto_alloc_size = sizeof(struct dm_demo_pdata),
+};
diff --git a/drivers/demo/demo-simple.c b/drivers/demo/demo-simple.c
new file mode 100644
index 0000000..2578f10
--- /dev/null
+++ b/drivers/demo/demo-simple.c
@@ -0,0 +1,61 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * (C) Copyright 2012
+ * Pavel Herrmann <morpheus.ibis@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm-demo.h>
+#include <asm/io.h>
+
+static int simple_hello(struct device *dev, int ch)
+{
+	const struct dm_demo_pdata *pdata = dev->platform_data;
+
+	printf("Hello from %08x: %s %d\n", map_to_sysmem(dev), pdata->colour,
+	       pdata->sides);
+
+	return 0;
+}
+
+static const struct demo_ops simple_ops = {
+	.hello = simple_hello,
+};
+
+static int demo_shape_probe(struct device *dev)
+{
+	/* Parse the data that is common with all demo devices */
+	return demo_parse_dt(dev);
+}
+
+static const struct device_id demo_shape_id[] = {
+	{ "demo-simple", 0 },
+	{ },
+};
+
+U_BOOT_DRIVER(demo_simple_drv) = {
+	.name	= "demo_simple_drv",
+	.of_match = demo_shape_id,
+	.id	= UCLASS_DEMO,
+	.probe	= demo_shape_probe,
+	.ops	= &simple_ops,
+	.ops	= &simple_ops,
+	.platform_data_auto_alloc_size = sizeof(struct dm_demo_pdata),
+};
diff --git a/drivers/demo/demo-uclass.c b/drivers/demo/demo-uclass.c
new file mode 100644
index 0000000..a7eab32
--- /dev/null
+++ b/drivers/demo/demo-uclass.c
@@ -0,0 +1,73 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * (C) Copyright 2012
+ * Pavel Herrmann <morpheus.ibis@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm-demo.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <linux/list.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+UCLASS_DRIVER(demo) = {
+	.id		= UCLASS_DEMO,
+};
+
+int demo_hello(struct device *dev, int ch)
+{
+	const struct demo_ops *ops = device_get_ops(dev);
+
+	if (!ops->hello)
+		return -ENOSYS;
+
+	return ops->hello(dev, ch);
+}
+
+int demo_status(struct device *dev, int *status)
+{
+	const struct demo_ops *ops = device_get_ops(dev);
+
+	if (!ops->status)
+		return -ENOSYS;
+
+	return ops->status(dev, status);
+}
+
+int demo_parse_dt(struct device *dev)
+{
+	struct dm_demo_pdata *pdata = dev->platform_data;
+	int dn = dev->of_offset;
+
+	if (dev->of_offset < 0)
+		return 0;
+	pdata->sides = fdtdec_get_int(gd->fdt_blob, dn, "sides", 0);
+	pdata->colour = fdt_getprop(gd->fdt_blob, dn, "colour", NULL);
+	if (!pdata->sides || !pdata->colour) {
+		debug("%s: Invalid device tree data\n", __func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}
diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
index 8e9a661..4537f36 100644
--- a/include/configs/sandbox.h
+++ b/include/configs/sandbox.h
@@ -23,7 +23,11 @@ 
 #define __CONFIG_H
 
 #define CONFIG_DM
+#define CONFIG_CMD_DEMO
 #define CONFIG_CMD_DM
+#define CONFIG_DM_DEMO
+#define CONFIG_DM_DEMO_SIMPLE
+#define CONFIG_DM_DEMO_SHAPE
 #define CONFIG_DM_TEST
 
 /* Number of bits in a C 'long' on this architecture */
diff --git a/include/dm-demo.h b/include/dm-demo.h
new file mode 100644
index 0000000..1041d29
--- /dev/null
+++ b/include/dm-demo.h
@@ -0,0 +1,49 @@ 
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __DM_DEMO_H
+#define __DM_DEMO_H
+
+#include <dm.h>
+
+/**
+ * struct dm_demo_pdata - configuration data for demo instance
+ *
+ * @colour: Color of the demo
+ * @sides: Numbers of sides
+ * @default_char: Default ASCII character to output (65 = 'A')
+ */
+struct dm_demo_pdata {
+	const char *colour;
+	int sides;
+	int default_char;
+};
+
+struct demo_ops {
+	int (*hello)(struct device *dev, int ch);
+	int (*status)(struct device *dev, int *status);
+};
+
+int demo_hello(struct device *dev, int ch);
+int demo_status(struct device *dev, int *status);
+int demo_list(void);
+
+int demo_parse_dt(struct device *dev);
+
+#endif