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Quick instructions are added in INSTALL.
Application source files are moved to src subdirectory.

Signed-off-by: Todor Tomov <ttomov@mm-sol.com>

9 files changed, 1934 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..b112ba6
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,3 @@
+bin_PROGRAMS = media-ctl
+media_ctl_SOURCES = main.c media.c media.h options.c options.h subdev.c subdev.h tools.h
+
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..aa4ced0
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,809 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/types.h>
+#include <linux/media.h>
+#include <linux/v4l2-mediabus.h>
+#include <linux/v4l2-subdev.h>
+#include <linux/videodev2.h>
+
+#include "media.h"
+#include "options.h"
+#include "subdev.h"
+#include "tools.h"
+
+/* -----------------------------------------------------------------------------
+ * Printing
+ */
+
+static struct {
+	const char *name;
+	enum v4l2_mbus_pixelcode code;
+} mbus_formats[] = {
+	{ "Y8", V4L2_MBUS_FMT_Y8_1X8},
+	{ "YUYV", V4L2_MBUS_FMT_YUYV8_1X16 },
+	{ "UYVY", V4L2_MBUS_FMT_UYVY8_1X16 },
+	{ "SGRBG10", V4L2_MBUS_FMT_SGRBG10_1X10 },
+	{ "SGRBG10_DPCM8", V4L2_MBUS_FMT_SGRBG10_DPCM8_1X8 },
+};
+
+static const char *pixelcode_to_string(enum v4l2_mbus_pixelcode code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(mbus_formats); ++i) {
+		if (mbus_formats[i].code == code)
+			return mbus_formats[i].name;
+	}
+
+	return "unknown";
+}
+
+static enum v4l2_mbus_pixelcode string_to_pixelcode(const char *string,
+					     unsigned int length)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(mbus_formats); ++i) {
+		if (strncmp(mbus_formats[i].name, string, length) == 0)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(mbus_formats))
+		return (enum v4l2_mbus_pixelcode)-1;
+
+	return mbus_formats[i].code;
+}
+
+static void v4l2_subdev_print_format(struct media_entity *entity,
+	unsigned int pad, enum v4l2_subdev_format_whence which)
+{
+	struct v4l2_mbus_framefmt format;
+	struct v4l2_rect rect;
+	int ret;
+
+	ret = v4l2_subdev_get_format(entity, &format, pad, which);
+	if (ret != 0)
+		return;
+
+	printf("[%s %ux%u", pixelcode_to_string(format.code),
+	       format.width, format.height);
+
+	ret = v4l2_subdev_get_crop(entity, &rect, pad, which);
+	if (ret == 0)
+		printf(" (%u,%u)/%ux%u", rect.left, rect.top,
+		       rect.width, rect.height);
+	printf("]");
+}
+
+static const char *media_entity_type_to_string(unsigned type)
+{
+	static const struct {
+		__u32 type;
+		const char *name;
+	} types[] = {
+		{ MEDIA_ENTITY_TYPE_NODE, "Node" },
+		{ MEDIA_ENTITY_TYPE_SUBDEV, "V4L2 subdev" },
+	};
+
+	unsigned int i;
+
+	type &= MEDIA_ENTITY_TYPE_MASK;
+
+	for (i = 0; i < ARRAY_SIZE(types); i++) {
+		if (types[i].type == type)
+			return types[i].name;
+	}
+
+	return "Unknown";
+}
+
+static const char *media_entity_subtype_to_string(unsigned type)
+{
+	static const char *node_types[] = {
+		"Unknown",
+		"V4L",
+		"FB",
+		"ALSA",
+		"DVB",
+	};
+	static const char *subdev_types[] = {
+		"Unknown",
+		"Sensor",
+		"Flash",
+		"Lens",
+	};
+
+	unsigned int subtype = type & MEDIA_ENTITY_SUBTYPE_MASK;
+
+	switch (type & MEDIA_ENTITY_TYPE_MASK) {
+	case MEDIA_ENTITY_TYPE_NODE:
+		if (subtype >= ARRAY_SIZE(node_types))
+			subtype = 0;
+		return node_types[subtype];
+
+	case MEDIA_ENTITY_TYPE_SUBDEV:
+		if (subtype >= ARRAY_SIZE(subdev_types))
+			subtype = 0;
+		return subdev_types[subtype];
+	default:
+		return node_types[0];
+	}
+}
+
+static const char *media_pad_type_to_string(unsigned flag)
+{
+	static const struct {
+		__u32 flag;
+		const char *name;
+	} flags[] = {
+		{ MEDIA_PAD_FLAG_INPUT, "Input" },
+		{ MEDIA_PAD_FLAG_OUTPUT, "Output" },
+	};
+
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(flags); i++) {
+		if (flags[i].flag & flag)
+			return flags[i].name;
+	}
+
+	return "Unknown";
+}
+
+static void media_print_topology_dot(struct media_device *media)
+{
+	unsigned int i, j;
+
+	printf("digraph board {\n");
+	printf("\trankdir=TB\n");
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+		unsigned int npads;
+
+		switch (media_entity_type(entity)) {
+		case MEDIA_ENTITY_TYPE_NODE:
+			printf("\tn%08x [label=\"%s\\n%s\", shape=box, style=filled, "
+			       "fillcolor=yellow]\n",
+			       entity->info.id, entity->info.name, entity->devname);
+			break;
+
+		case MEDIA_ENTITY_TYPE_SUBDEV:
+			printf("\tn%08x [label=\"{{", entity->info.id);
+
+			for (j = 0, npads = 0; j < entity->info.pads; ++j) {
+				if (!(entity->pads[j].flags & MEDIA_PAD_FLAG_INPUT))
+					continue;
+
+				printf("%s<port%u> %u", npads ? " | " : "", j, j);
+				npads++;
+			}
+
+			printf("} | %s", entity->info.name);
+			if (entity->devname)
+				printf("\\n%s", entity->devname);
+			printf(" | {");
+
+			for (j = 0, npads = 0; j < entity->info.pads; ++j) {
+				if (!(entity->pads[j].flags & MEDIA_PAD_FLAG_OUTPUT))
+					continue;
+
+				printf("%s<port%u> %u", npads ? " | " : "", j, j);
+				npads++;
+			}
+
+			printf("}}\", shape=Mrecord, style=filled, fillcolor=green]\n");
+			break;
+
+		default:
+			continue;
+		}
+
+		for (j = 0; j < entity->num_links; j++) {
+			struct media_link *link = &entity->links[j];
+
+			if (link->source->entity != entity)
+				continue;
+
+			printf("\tn%08x", link->source->entity->info.id);
+			if (media_entity_type(link->source->entity) == MEDIA_ENTITY_TYPE_SUBDEV)
+				printf(":port%u", link->source->index);
+			printf(" -> ");
+			printf("n%08x", link->sink->entity->info.id);
+			if (media_entity_type(link->sink->entity) == MEDIA_ENTITY_TYPE_SUBDEV)
+				printf(":port%u", link->sink->index);
+
+			if (link->flags & MEDIA_LINK_FLAG_IMMUTABLE)
+				printf(" [style=bold]");
+			else if (!(link->flags & MEDIA_LINK_FLAG_ACTIVE))
+				printf(" [style=dashed]");
+			printf("\n");
+		}
+	}
+
+	printf("}\n");
+}
+
+static void media_print_topology_text(struct media_device *media)
+{
+	unsigned int i, j, k;
+	unsigned int padding;
+
+	printf("Device topology\n");
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+
+		padding = printf("- entity %u: ", entity->info.id);
+		printf("%s (%u pad%s, %u link%s)\n", entity->info.name,
+			entity->info.pads, entity->info.pads > 1 ? "s" : "",
+			entity->info.links, entity->info.links > 1 ? "s" : "");
+		printf("%*ctype %s subtype %s\n", padding, ' ',
+			media_entity_type_to_string(entity->info.type),
+			media_entity_subtype_to_string(entity->info.type));
+		if (entity->devname[0])
+			printf("%*cdevice node name %s\n", padding, ' ', entity->devname);
+
+		for (j = 0; j < entity->info.pads; j++) {
+			struct media_pad *pad = &entity->pads[j];
+
+			printf("\tpad%u: %s ", j, media_pad_type_to_string(pad->flags));
+
+			if (media_entity_type(entity) == MEDIA_ENTITY_TYPE_SUBDEV)
+				v4l2_subdev_print_format(entity, j, V4L2_SUBDEV_FORMAT_ACTIVE);
+
+			printf("\n");
+
+			for (k = 0; k < entity->num_links; k++) {
+				struct media_link *link = &entity->links[k];
+
+				if (link->source->entity != entity ||
+				    link->source->index != j)
+					continue;
+
+				printf("\t\t-> '%s':pad%u [",
+					link->sink->entity->info.name, link->sink->index);
+
+				if (link->flags & MEDIA_LINK_FLAG_IMMUTABLE)
+					printf("IMMUTABLE,");
+				if (link->flags & MEDIA_LINK_FLAG_ACTIVE)
+					printf("ACTIVE");
+
+				printf("]\n");
+			}
+		}
+		printf("\n");
+	}
+}
+
+void media_print_topology(struct media_device *media, int dot)
+{
+	if (dot)
+		media_print_topology_dot(media);
+	else
+		media_print_topology_text(media);
+}
+
+/* -----------------------------------------------------------------------------
+ * Links setup
+ */
+
+static struct media_pad *parse_pad(struct media_device *media, const char *p, char **endp)
+{
+	unsigned int entity_id, pad;
+	struct media_entity *entity;
+	char *end;
+
+	for (; isspace(*p); ++p);
+
+	if (*p == '"') {
+		for (end = (char *)p + 1; *end && *end != '"'; ++end);
+		if (*end != '"')
+			return NULL;
+
+		entity = media_get_entity_by_name(media, p + 1, end - p - 1);
+		if (entity == NULL)
+			return NULL;
+
+		++end;
+	} else {
+		entity_id = strtoul(p, &end, 10);
+		entity = media_get_entity_by_id(media, entity_id);
+		if (entity == NULL)
+			return NULL;
+	}
+	for (; isspace(*end); ++end);
+
+	if (*end != ':')
+		return NULL;
+	for (p = end + 1; isspace(*p); ++p);
+
+	pad = strtoul(p, &end, 10);
+	for (p = end; isspace(*p); ++p);
+
+	if (pad >= entity->info.pads)
+		return NULL;
+
+	for (p = end; isspace(*p); ++p);
+	if (endp)
+		*endp = (char *)p;
+
+	return &entity->pads[pad];
+}
+
+static struct media_link *parse_link(struct media_device *media, const char *p, char **endp)
+{
+	struct media_link *link;
+	struct media_pad *source;
+	struct media_pad *sink;
+	unsigned int i;
+	char *end;
+
+	source = parse_pad(media, p, &end);
+	if (source == NULL)
+		return NULL;
+
+	if (end[0] != '-' || end[1] != '>')
+		return NULL;
+	p = end + 2;
+
+	sink = parse_pad(media, p, &end);
+	if (sink == NULL)
+		return NULL;
+
+	*endp = end;
+
+	for (i = 0; i < source->entity->num_links; i++) {
+		link = &source->entity->links[i];
+
+		if (link->source == source && link->sink == sink)
+			return link;
+	}
+
+	return NULL;
+}
+
+static int setup_link(struct media_device *media, const char *p, char **endp)
+{
+	struct media_link *link;
+	__u32 flags;
+	char *end;
+
+	link = parse_link(media, p, &end);
+	if (link == NULL) {
+		printf("Unable to parse link\n");
+		return -EINVAL;
+	}
+
+	p = end;
+	if (*p++ != '[') {
+		printf("Unable to parse link flags\n");
+		return -EINVAL;
+	}
+
+	flags = strtoul(p, &end, 10);
+	for (p = end; isspace(*p); p++);
+	if (*p++ != ']') {
+		printf("Unable to parse link flags\n");
+		return -EINVAL;
+	}
+
+	for (; isspace(*p); p++);
+	*endp = (char *)p;
+
+	printf("Setting up link %u:%u -> %u:%u [%u]\n",
+		link->source->entity->info.id, link->source->index,
+		link->sink->entity->info.id, link->sink->index,
+		flags);
+
+	return media_setup_link(media, link->source, link->sink, flags);
+}
+
+static int setup_links(struct media_device *media, const char *p)
+{
+	char *end;
+	int ret;
+
+	do {
+		ret = setup_link(media, p, &end);
+		if (ret < 0)
+			return ret;
+
+		p = end + 1;
+	} while (*end == ',');
+
+	return *end ? -EINVAL : 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * Formats setup
+ */
+
+static int parse_format(struct v4l2_mbus_framefmt *format, const char *p, char **endp)
+{
+	enum v4l2_mbus_pixelcode code;
+	unsigned int width, height;
+	char *end;
+
+	for (; isspace(*p); ++p);
+	for (end = (char *)p; !isspace(*end) && *end != '\0'; ++end);
+
+	code = string_to_pixelcode(p, end - p);
+	if (code == (enum v4l2_mbus_pixelcode)-1)
+		return -EINVAL;
+
+	for (p = end; isspace(*p); ++p);
+	width = strtoul(p, &end, 10);
+	if (*end != 'x')
+		return -EINVAL;
+
+	p = end + 1;
+	height = strtoul(p, &end, 10);
+	*endp = end;
+
+	memset(format, 0, sizeof(*format));
+	format->width = width;
+	format->height = height;
+	format->code = code;
+
+	return 0;
+}
+
+static int parse_crop(struct v4l2_rect *crop, const char *p, char **endp)
+{
+	char *end;
+
+	if (*p++ != '(')
+		return -EINVAL;
+
+	crop->left = strtoul(p, &end, 10);
+	if (*end != ',')
+		return -EINVAL;
+
+	p = end + 1;
+	crop->top = strtoul(p, &end, 10);
+	if (*end++ != ')')
+		return -EINVAL;
+	if (*end != '/')
+		return -EINVAL;
+
+	p = end + 1;
+	crop->width = strtoul(p, &end, 10);
+	if (*end != 'x')
+		return -EINVAL;
+
+	p = end + 1;
+	crop->height = strtoul(p, &end, 10);
+	*endp = end;
+
+	return 0;
+}
+
+static int parse_frame_interval(struct v4l2_fract *interval, const char *p, char **endp)
+{
+	char *end;
+
+	for (; isspace(*p); ++p);
+
+	interval->numerator = strtoul(p, &end, 10);
+
+	for (p = end; isspace(*p); ++p);
+	if (*p++ != '/')
+		return -EINVAL;
+
+	for (; isspace(*p); ++p);
+	interval->denominator = strtoul(p, &end, 10);
+
+	*endp = end;
+	return 0;
+}
+
+static struct media_pad *parse_pad_format(struct media_device *media,
+	struct v4l2_mbus_framefmt *format, struct v4l2_rect *crop,
+	struct v4l2_fract *interval, const char *p, char **endp)
+{
+	struct media_pad *pad;
+	char *end;
+	int ret;
+
+	for (; isspace(*p); ++p);
+
+	pad = parse_pad(media, p, &end);
+	if (pad == NULL)
+		return NULL;
+
+	for (p = end; isspace(*p); ++p);
+	if (*p++ != '[')
+		return NULL;
+
+	for (; isspace(*p); ++p);
+
+	if (isalnum(*p)) {
+		ret = parse_format(format, p, &end);
+		if (ret < 0)
+			return NULL;
+
+		for (p = end; isspace(*p); p++);
+	}
+
+	if (*p == '(') {
+		ret = parse_crop(crop, p, &end);
+		if (ret < 0)
+			return NULL;
+
+		for (p = end; isspace(*p); p++);
+	}
+
+	if (*p == '@') {
+		ret = parse_frame_interval(interval, ++p, &end);
+		if (ret < 0)
+			return NULL;
+
+		for (p = end; isspace(*p); p++);
+	}
+
+	if (*p != ']')
+		return NULL;
+
+	*endp = (char *)p + 1;
+	return pad;
+}
+
+static int set_format(struct media_pad *pad, struct v4l2_mbus_framefmt *format)
+{
+	int ret;
+
+	if (format->width == 0 || format->height == 0)
+		return 0;
+
+	printf("Setting up format %s %ux%u on pad %s/%u\n",
+		pixelcode_to_string(format->code), format->width, format->height,
+		pad->entity->info.name, pad->index);
+
+	ret = v4l2_subdev_set_format(pad->entity, format, pad->index,
+				     V4L2_SUBDEV_FORMAT_ACTIVE);
+	if (ret < 0) {
+		printf("Unable to set format: %s (%d)\n", strerror(-ret), ret);
+		return ret;
+	}
+
+	printf("Format set: %s %ux%u\n",
+		pixelcode_to_string(format->code), format->width, format->height);
+
+	return 0;
+}
+
+static int set_crop(struct media_pad *pad, struct v4l2_rect *crop)
+{
+	int ret;
+
+	if (crop->left == -1 || crop->top == -1)
+		return 0;
+
+	printf("Setting up crop rectangle (%u,%u)/%ux%u on pad %s/%u\n",
+		crop->left, crop->top, crop->width, crop->height,
+		pad->entity->info.name, pad->index);
+
+	ret = v4l2_subdev_set_crop(pad->entity, crop, pad->index,
+				   V4L2_SUBDEV_FORMAT_ACTIVE);
+	if (ret < 0) {
+		printf("Unable to set crop rectangle: %s (%d)\n", strerror(-ret), ret);
+		return ret;
+	}
+
+	printf("Crop rectangle set: (%u,%u)/%ux%u\n",
+		crop->left, crop->top, crop->width, crop->height);
+
+	return 0;
+}
+
+static int set_frame_interval(struct media_entity *entity, struct v4l2_fract *interval)
+{
+	int ret;
+
+	if (interval->numerator == 0)
+		return 0;
+
+	printf("Setting up frame interval %u/%u on entity %s\n",
+		interval->numerator, interval->denominator, entity->info.name);
+
+	ret = v4l2_subdev_set_frame_interval(entity, interval);
+	if (ret < 0) {
+		printf("Unable to set frame interval: %s (%d)", strerror(-ret), ret);
+		return ret;
+	}
+
+	printf("Frame interval set: %u/%u\n",
+		interval->numerator, interval->denominator);
+
+	return 0;
+}
+
+
+static int setup_format(struct media_device *media, const char *p, char **endp)
+{
+	struct v4l2_mbus_framefmt format = { 0, 0, 0 };
+	struct media_pad *pad;
+	struct v4l2_rect crop = { -1, -1, -1, -1 };
+	struct v4l2_fract interval = { 0, 0 };
+	unsigned int i;
+	char *end;
+	int ret;
+
+	pad = parse_pad_format(media, &format, &crop, &interval, p, &end);
+	if (pad == NULL) {
+		printf("Unable to parse format\n");
+		return -EINVAL;
+	}
+
+	if (pad->flags & MEDIA_PAD_FLAG_OUTPUT) {
+		ret = set_crop(pad, &crop);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = set_format(pad, &format);
+	if (ret < 0)
+		return ret;
+
+	if (pad->flags & MEDIA_PAD_FLAG_INPUT) {
+		ret = set_crop(pad, &crop);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = set_frame_interval(pad->entity, &interval);
+	if (ret < 0)
+		return ret;
+
+
+	/* If the pad is an output pad, automatically set the same format on
+	 * the remote subdev input pads, if any.
+	 */
+	if (pad->flags & MEDIA_PAD_FLAG_OUTPUT) {
+		for (i = 0; i < pad->entity->num_links; ++i) {
+			struct media_link *link = &pad->entity->links[i];
+			struct v4l2_mbus_framefmt remote_format;
+
+			if (!(link->flags & MEDIA_LINK_FLAG_ACTIVE))
+				continue;
+
+			if (link->source == pad &&
+			    link->sink->entity->info.type == MEDIA_ENTITY_TYPE_SUBDEV) {
+				remote_format = format;
+				set_format(link->sink, &remote_format);
+			}
+		}
+	}
+
+	*endp = end;
+	return 0;
+}
+
+static int setup_formats(struct media_device *media, const char *p)
+{
+	char *end;
+	int ret;
+
+	do {
+		ret = setup_format(media, p, &end);
+		if (ret < 0)
+			return ret;
+
+		p = end + 1;
+	} while (*end == ',');
+
+	return *end ? -EINVAL : 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct media_device *media;
+	int ret = -1;
+
+	if (parse_cmdline(argc, argv))
+		return EXIT_FAILURE;
+
+	/* Open the media device and enumerate entities, pads and links. */
+	media = media_open(media_opts.devname, media_opts.verbose);
+	if (media == NULL)
+		goto out;
+
+	if (media_opts.entity) {
+		struct media_entity *entity;
+
+		entity = media_get_entity_by_name(media, media_opts.entity,
+						  strlen(media_opts.entity));
+		if (entity == NULL) {
+			printf("Entity '%s' not found\n", media_opts.entity);
+			goto out;
+		}
+
+		printf("%s\n", entity->devname);
+	}
+
+	if (media_opts.pad) {
+		struct media_pad *pad;
+
+		pad = parse_pad(media, media_opts.pad, NULL);
+		if (pad == NULL) {
+			printf("Pad '%s' not found\n", media_opts.pad);
+			goto out;
+		}
+
+		v4l2_subdev_print_format(pad->entity, pad->index,
+					 V4L2_SUBDEV_FORMAT_ACTIVE);
+		printf("\n");
+	}
+
+	if (media_opts.print || media_opts.print_dot) {
+		media_print_topology(media, media_opts.print_dot);
+		printf("\n");
+	}
+
+	if (media_opts.reset) {
+		printf("Resetting all links to inactive\n");
+		media_reset_links(media);
+	}
+
+	if (media_opts.links)
+		setup_links(media, media_opts.links);
+
+	if (media_opts.formats)
+		setup_formats(media, media_opts.formats);
+
+	if (media_opts.interactive) {
+		while (1) {
+			char buffer[32];
+			char *end;
+
+			printf("Enter a link to modify or enter to stop\n");
+			if (fgets(buffer, sizeof buffer, stdin) == NULL)
+				break;
+
+			if (buffer[0] == '\n')
+				break;
+
+			setup_link(media, buffer, &end);
+		}
+	}
+
+	ret = 0;
+
+out:
+	if (media)
+		media_close(media);
+
+	return ret ? EXIT_FAILURE : EXIT_SUCCESS;
+}
+
diff --git a/src/media.c b/src/media.c
new file mode 100644
index 0000000..456b882
--- /dev/null
+++ b/src/media.c
@@ -0,0 +1,388 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <linux/videodev2.h>
+#include <linux/media.h>
+
+#include "media.h"
+#include "tools.h"
+
+struct media_pad *media_entity_remote_source(struct media_pad *pad)
+{
+	unsigned int i;
+
+	if (!(pad->flags & MEDIA_PAD_FLAG_INPUT))
+		return NULL;
+
+	for (i = 0; i < pad->entity->num_links; ++i) {
+		struct media_link *link = &pad->entity->links[i];
+
+		if (!(link->flags & MEDIA_LINK_FLAG_ACTIVE))
+			continue;
+
+		if (link->sink == pad)
+			return link->source;
+	}
+
+	return NULL;
+}
+
+struct media_entity *media_get_entity_by_name(struct media_device *media,
+					      const char *name, size_t length)
+{
+	unsigned int i;
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+
+		if (strncmp(entity->info.name, name, length) == 0)
+			return entity;
+	}
+
+	return NULL;
+}
+
+struct media_entity *media_get_entity_by_id(struct media_device *media,
+					    __u32 id)
+{
+	unsigned int i;
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+
+		if (entity->info.id == id)
+			return entity;
+	}
+
+	return NULL;
+}
+
+int media_setup_link(struct media_device *media,
+		     struct media_pad *source,
+		     struct media_pad *sink,
+		     __u32 flags)
+{
+	struct media_link *link;
+	struct media_link_desc ulink;
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < source->entity->num_links; i++) {
+		link = &source->entity->links[i];
+
+		if (link->source->entity == source->entity &&
+		    link->source->index == source->index &&
+		    link->sink->entity == sink->entity &&
+		    link->sink->index == sink->index)
+			break;
+	}
+
+	if (i == source->entity->num_links) {
+		printf("%s: Link not found\n", __func__);
+		return -EINVAL;
+	}
+
+	/* source pad */
+	ulink.source.entity = source->entity->info.id;
+	ulink.source.index = source->index;
+	ulink.source.flags = MEDIA_PAD_FLAG_OUTPUT;
+
+	/* sink pad */
+	ulink.sink.entity = sink->entity->info.id;
+	ulink.sink.index = sink->index;
+	ulink.sink.flags = MEDIA_PAD_FLAG_INPUT;
+
+	ulink.flags = flags | (link->flags & MEDIA_LINK_FLAG_IMMUTABLE);
+
+	ret = ioctl(media->fd, MEDIA_IOC_SETUP_LINK, &ulink);
+	if (ret < 0) {
+		printf("%s: Unable to setup link (%s)\n", __func__,
+			strerror(errno));
+		return ret;
+	}
+
+	link->flags = flags;
+	return 0;
+}
+
+int media_reset_links(struct media_device *media)
+{
+	unsigned int i, j;
+	int ret;
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+
+		for (j = 0; j < entity->num_links; j++) {
+			struct media_link *link = &entity->links[j];
+
+			if (link->flags & MEDIA_LINK_FLAG_IMMUTABLE ||
+			    link->source->entity != entity)
+				continue;
+
+			ret = media_setup_link(media, link->source, link->sink,
+					       link->flags & ~MEDIA_LINK_FLAG_ACTIVE);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static struct media_link *media_entity_add_link(struct media_entity *entity)
+{
+	if (entity->num_links >= entity->max_links) {
+		struct media_link *links = entity->links;
+		unsigned int max_links = entity->max_links * 2;
+		unsigned int i;
+
+		links = realloc(links, max_links * sizeof *links);
+		if (links == NULL)
+			return NULL;
+
+		for (i = 0; i < entity->num_links; ++i)
+			links[i].twin->twin = &links[i];
+
+		entity->max_links = max_links;
+		entity->links = links;
+	}
+
+	return &entity->links[entity->num_links++];
+}
+
+static int media_enum_links(struct media_device *media)
+{
+	__u32 id;
+	int ret = 0;
+
+	for (id = 1; id <= media->entities_count; id++) {
+		struct media_entity *entity = &media->entities[id - 1];
+		struct media_links_enum links;
+		unsigned int i;
+
+		links.entity = entity->info.id;
+		links.pads = malloc(entity->info.pads * sizeof(struct media_pad_desc));
+		links.links = malloc(entity->info.links * sizeof(struct media_link_desc));
+
+		if (ioctl(media->fd, MEDIA_IOC_ENUM_LINKS, &links) < 0) {
+			printf("%s: Unable to enumerate pads and links (%s).\n",
+				__func__, strerror(errno));
+			free(links.pads);
+			free(links.links);
+			return -errno;
+		}
+
+		for (i = 0; i < entity->info.pads; ++i) {
+			entity->pads[i].entity = entity;
+			entity->pads[i].index = links.pads[i].index;
+			entity->pads[i].flags = links.pads[i].flags;
+		}
+
+		for (i = 0; i < entity->info.links; ++i) {
+			struct media_link_desc *link = &links.links[i];
+			struct media_link *fwdlink;
+			struct media_link *backlink;
+			struct media_entity *source;
+			struct media_entity *sink;
+
+			source = media_get_entity_by_id(media, link->source.entity);
+			sink = media_get_entity_by_id(media, link->sink.entity);
+
+			if (source == NULL || sink == NULL) {
+				printf("WARNING entity %u link %u from %u/%u to %u/%u is invalid!\n",
+					id, i, link->source.entity, link->source.index,
+					link->sink.entity, link->sink.index);
+				ret = -EINVAL;
+			} else {
+				fwdlink = media_entity_add_link(source);
+				fwdlink->source = &source->pads[link->source.index];
+				fwdlink->sink = &sink->pads[link->sink.index];
+				fwdlink->flags = links.links[i].flags;
+
+				backlink = media_entity_add_link(sink);
+				backlink->source = &source->pads[link->source.index];
+				backlink->sink = &sink->pads[link->sink.index];
+				backlink->flags = links.links[i].flags;
+
+				fwdlink->twin = backlink;
+				backlink->twin = fwdlink;
+			}
+		}
+
+		free(links.pads);
+		free(links.links);
+	}
+
+	return ret;
+}
+
+static int media_enum_entities(struct media_device *media)
+{
+	struct media_entity *entity;
+	struct stat devstat;
+	unsigned int size;
+	char devname[32];
+	char sysname[32];
+	char target[1024];
+	char *p;
+	__u32 id;
+	int ret;
+
+	for (id = 0; ; id = entity->info.id) {
+		size = (media->entities_count + 1) * sizeof(*media->entities);
+		media->entities = realloc(media->entities, size);
+
+		entity = &media->entities[media->entities_count];
+		memset(entity, 0, sizeof(*entity));
+		entity->fd = -1;
+		entity->info.id = id | MEDIA_ENTITY_ID_FLAG_NEXT;
+
+		ret = ioctl(media->fd, MEDIA_IOC_ENUM_ENTITIES, &entity->info);
+		if (ret < 0) {
+			if (errno == EINVAL)
+				break;
+			return -errno;
+		}
+
+		/* Number of links (for outbound links) plus number of pads (for
+		 * inbound links) is a good safe initial estimate of the total
+		 * number of links.
+		 */
+		entity->max_links = entity->info.pads + entity->info.links;
+
+		entity->pads = malloc(entity->info.pads * sizeof(*entity->pads));
+		entity->links = malloc(entity->max_links * sizeof(*entity->links));
+		if (entity->pads == NULL || entity->links == NULL)
+			return -ENOMEM;
+
+		media->entities_count++;
+
+		/* Find the corresponding device name. */
+		if (media_entity_type(entity) != MEDIA_ENTITY_TYPE_NODE &&
+		    media_entity_type(entity) != MEDIA_ENTITY_TYPE_SUBDEV)
+			continue;
+
+		sprintf(sysname, "/sys/dev/char/%u:%u", entity->info.v4l.major,
+			entity->info.v4l.minor);
+		ret = readlink(sysname, target, sizeof(target));
+		if (ret < 0)
+			continue;
+
+		target[ret] = '\0';
+		p = strrchr(target, '/');
+		if (p == NULL)
+			continue;
+
+		sprintf(devname, "/dev/%s", p + 1);
+		ret = stat(devname, &devstat);
+		if (ret < 0)
+			continue;
+
+		/* Sanity check: udev might have reordered the device nodes.
+		 * Make sure the major/minor match. We should really use
+		 * libudev.
+		 */
+		if (major(devstat.st_rdev) == entity->info.v4l.major &&
+		    minor(devstat.st_rdev) == entity->info.v4l.minor)
+			strcpy(entity->devname, devname);
+	}
+
+	return 0;
+}
+
+struct media_device *media_open(const char *name, int verbose)
+{
+	struct media_device *media;
+	int ret;
+
+	media = malloc(sizeof(*media));
+	if (media == NULL) {
+		printf("%s: unable to allocate memory\n", __func__);
+		return NULL;
+	}
+	memset(media, 0, sizeof(*media));
+
+	if (verbose)
+		printf("Opening media device %s\n", name);
+	media->fd = open(name, O_RDWR);
+	if (media->fd < 0) {
+		media_close(media);
+		printf("%s: Can't open media device %s\n", __func__, name);
+		return NULL;
+	}
+
+	if (verbose)
+		printf("Enumerating entities\n");
+
+	ret = media_enum_entities(media);
+	if (ret < 0) {
+		printf("%s: Unable to enumerate entities for device %s (%s)\n",
+			__func__, name, strerror(-ret));
+		media_close(media);
+		return NULL;
+	}
+
+	if (verbose) {
+		printf("Found %u entities\n", media->entities_count);
+		printf("Enumerating pads and links\n");
+	}
+
+	ret = media_enum_links(media);
+	if (ret < 0) {
+		printf("%s: Unable to enumerate pads and linksfor device %s\n",
+			__func__, name);
+		media_close(media);
+		return NULL;
+	}
+
+	return media;
+}
+
+void media_close(struct media_device *media)
+{
+	unsigned int i;
+
+	if (media->fd != -1)
+		close(media->fd);
+
+	for (i = 0; i < media->entities_count; ++i) {
+		struct media_entity *entity = &media->entities[i];
+
+		free(entity->pads);
+		free(entity->links);
+		if (entity->fd != -1)
+			close(entity->fd);
+	}
+
+	free(media->entities);
+	free(media);
+}
+
diff --git a/src/media.h b/src/media.h
new file mode 100644
index 0000000..80cf976
--- /dev/null
+++ b/src/media.h
@@ -0,0 +1,161 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#ifndef __MEDIA_H__
+#define __MEDIA_H__
+
+#include <linux/media.h>
+
+struct media_link {
+	struct media_pad *source;
+	struct media_pad *sink;
+	struct media_link *twin;
+	__u32 flags;
+	__u32 padding[3];
+};
+
+struct media_pad {
+	struct media_entity *entity;
+	__u32 index;
+	__u32 flags;
+	__u32 padding[3];
+};
+
+struct media_entity {
+	struct media_entity_desc info;
+	struct media_pad *pads;
+	struct media_link *links;
+	unsigned int max_links;
+	unsigned int num_links;
+
+	char devname[32];
+	int fd;
+	__u32 padding[6];
+};
+
+struct media_device {
+	int fd;
+	struct media_entity *entities;
+	unsigned int entities_count;
+	__u32 padding[6];
+};
+
+/**
+ * @brief Open a media device.
+ * @param name - name (including path) of the device node.
+ * @param verbose - whether to print verbose information on the standard output.
+ *
+ * Open the media device referenced by @a name and enumerate entities, pads and
+ * links.
+ *
+ * @return A pointer to a newly allocated media_device structure instance on
+ * success and NULL on failure. The returned pointer must be freed with
+ * media_close when the device isn't needed anymore.
+ */
+struct media_device *media_open(const char *name, int verbose);
+
+/**
+ * @brief Close a media device.
+ * @param media - device instance.
+ *
+ * Close the @a media device instance and free allocated resources. Access to the
+ * device instance is forbidden after this function returns.
+ */
+void media_close(struct media_device *media);
+
+/**
+ * @brief Locate the pad at the other end of a link.
+ * @param pad - sink pad at one end of the link.
+ *
+ * Locate the source pad connected to @a pad through an enabled link. As only one
+ * link connected to a sink pad can be enabled at a time, the connected source
+ * pad is guaranteed to be unique.
+ *
+ * @return A pointer to the connected source pad, or NULL if all links connected
+ * to @a pad are disabled. Return NULL also if @a pad is not a sink pad.
+ */
+struct media_pad *media_entity_remote_source(struct media_pad *pad);
+
+/**
+ * @brief Get the type of an entity.
+ * @param entity - the entity.
+ *
+ * @return The type of @a entity.
+ */
+static inline unsigned int media_entity_type(struct media_entity *entity)
+{
+	return entity->info.type & MEDIA_ENTITY_TYPE_MASK;
+}
+
+/**
+ * @brief Find an entity by its name.
+ * @param media - media device.
+ * @param name - entity name.
+ * @param length - size of @a name.
+ *
+ * Search for an entity with a name equal to @a name.
+ *
+ * @return A pointer to the entity if found, or NULL otherwise.
+ */
+struct media_entity *media_get_entity_by_name(struct media_device *media,
+	const char *name, size_t length);
+
+/**
+ * @brief Find an entity by its ID.
+ * @param media - media device.
+ * @param id - entity ID.
+ *
+ * Search for an entity with an ID equal to @a id.
+ *
+ * @return A pointer to the entity if found, or NULL otherwise.
+ */
+struct media_entity *media_get_entity_by_id(struct media_device *media,
+	__u32 id);
+
+/**
+ * @brief Configure a link.
+ * @param media - media device.
+ * @param source - source pad at the link origin.
+ * @param sink - sink pad at the link target.
+ * @param flags - configuration flags.
+ *
+ * Locate the link between @a source and @a sink, and configure it by applying
+ * the new @a flags.
+ *
+ * Only the MEDIA_LINK_FLAG_ENABLED flag is writable.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int media_setup_link(struct media_device *media,
+	struct media_pad *source, struct media_pad *sink,
+	__u32 flags);
+
+/**
+ * @brief Reset all links to the disabled state.
+ * @param media - media device.
+ *
+ * Disable all links in the media device. This function is usually used after
+ * opening a media device to reset all links to a known state.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int media_reset_links(struct media_device *media);
+
+#endif
+
diff --git a/src/options.c b/src/options.c
new file mode 100644
index 0000000..186425e
--- /dev/null
+++ b/src/options.c
@@ -0,0 +1,155 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#include <stdlib.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "options.h"
+
+#define MEDIA_DEVNAME_DEFAULT		"/dev/media0"
+
+struct media_options media_opts = {
+	.devname = MEDIA_DEVNAME_DEFAULT,
+};
+
+static void usage(const char *argv0, int verbose)
+{
+	printf("%s [options] device\n", argv0);
+	printf("-d, --device dev	Media device name (default: %s)\n", MEDIA_DEVNAME_DEFAULT);
+	printf("-e, --entity name	Print the device name associated with the given entity\n");
+	printf("-f, --set-format	Comma-separated list of formats to setup\n");
+	printf("    --get-format pad	Print the active format on a given pad\n");
+	printf("-h, --help		Show verbose help and exit\n");
+	printf("-i, --interactive	Modify links interactively\n");
+	printf("-l, --links		Comma-separated list of links descriptors to setup\n");
+	printf("-p, --print-topology	Print the device topology (implies -v)\n");
+	printf("    --print-dot		Print the device topology as a dot graph (implies -v)\n");
+	printf("-r, --reset		Reset all links to inactive\n");
+	printf("-v, --verbose		Be verbose\n");
+
+	if (!verbose)
+		return;
+
+	printf("\n");
+	printf("Links and formats are defined as\n");
+	printf("\tlink            = pad, '->', pad, '[', flags, ']' ;\n");
+	printf("\tformat          = pad, '[', fcc, ' ', size, [ ' ', crop ], [ ' ', '@', frame interval ], ']' ;\n");
+	printf("\tpad             = entity, ':', pad number ;\n");
+	printf("\tentity          = entity number | ( '\"', entity name, '\"' ) ;\n");
+	printf("\tsize            = width, 'x', height ;\n");
+	printf("\tcrop            = '(', left, ',', top, ')', '/', size ;\n");
+	printf("\tframe interval  = numerator, '/', denominator ;\n");
+	printf("where the fields are\n");
+	printf("\tentity number   Entity numeric identifier\n");
+	printf("\tentity name     Entity name (string) \n");
+	printf("\tpad number      Pad numeric identifier\n");
+	printf("\tflags           Link flags (0: inactive, 1: active)\n");
+	printf("\tfcc             Format FourCC\n");
+	printf("\twidth           Image width in pixels\n");
+	printf("\theight          Image height in pixels\n");
+	printf("\tnumerator       Frame interval numerator\n");
+	printf("\tdenominator     Frame interval denominator\n");
+}
+
+#define OPT_PRINT_DOT		256
+#define OPT_GET_FORMAT		257
+
+static struct option opts[] = {
+	{"device", 1, 0, 'd'},
+	{"entity", 1, 0, 'e'},
+	{"set-format", 1, 0, 'f'},
+	{"get-format", 1, 0, OPT_GET_FORMAT},
+	{"help", 0, 0, 'h'},
+	{"interactive", 0, 0, 'i'},
+	{"links", 1, 0, 'l'},
+	{"print-dot", 0, 0, OPT_PRINT_DOT},
+	{"print-topology", 0, 0, 'p'},
+	{"reset", 0, 0, 'r'},
+	{"verbose", 0, 0, 'v'},
+};
+
+int parse_cmdline(int argc, char **argv)
+{
+	int opt;
+
+	if (argc == 1) {
+		usage(argv[0], 0);
+		return 1;
+	}
+
+	/* parse options */
+	while ((opt = getopt_long(argc, argv, "d:e:f:hil:prv", opts, NULL)) != -1) {
+		switch (opt) {
+		case 'd':
+			media_opts.devname = optarg;
+			break;
+
+		case 'e':
+			media_opts.entity = optarg;
+			break;
+
+		case 'f':
+			media_opts.formats = optarg;
+			break;
+
+		case 'h':
+			usage(argv[0], 1);
+			exit(0);
+
+		case 'i':
+			media_opts.interactive = 1;
+			break;
+
+		case 'l':
+			media_opts.links = optarg;
+			break;
+
+		case 'p':
+			media_opts.print = 1;
+			media_opts.verbose = 1;
+			break;
+
+		case 'r':
+			media_opts.reset = 1;
+			break;
+
+		case 'v':
+			media_opts.verbose = 1;
+			break;
+
+		case OPT_PRINT_DOT:
+			media_opts.print_dot = 1;
+			break;
+
+		case OPT_GET_FORMAT:
+			media_opts.pad = optarg;
+			break;
+
+		default:
+			printf("Invalid option -%c\n", opt);
+			printf("Run %s -h for help.\n", argv[0]);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
diff --git a/src/options.h b/src/options.h
new file mode 100644
index 0000000..2467fbe
--- /dev/null
+++ b/src/options.h
@@ -0,0 +1,42 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#ifndef __OPTIONS_H
+#define __OPTIONS_H
+
+struct media_options
+{
+	const char *devname;
+	unsigned int interactive:1,
+		     print:1,
+		     print_dot:1,
+		     reset:1,
+		     verbose:1;
+	const char *entity;
+	const char *formats;
+	const char *links;
+	const char *pad;
+};
+
+extern struct media_options media_opts;
+
+extern int parse_cmdline(int argc, char **argv);
+
+#endif /* __OPTIONS_H */
+
diff --git a/src/subdev.c b/src/subdev.c
new file mode 100644
index 0000000..3960d05
--- /dev/null
+++ b/src/subdev.c
@@ -0,0 +1,187 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <linux/v4l2-subdev.h>
+
+#include "media.h"
+#include "subdev.h"
+#include "tools.h"
+
+int v4l2_subdev_open(struct media_entity *entity)
+{
+	if (entity->fd != -1)
+		return 0;
+
+	entity->fd = open(entity->devname, O_RDWR);
+	if (entity->fd == -1) {
+		printf("%s: Failed to open subdev device node %s\n", __func__,
+			entity->devname);
+		return -errno;
+	}
+
+	return 0;
+}
+
+void v4l2_subdev_close(struct media_entity *entity)
+{
+	close(entity->fd);
+}
+
+int v4l2_subdev_get_format(struct media_entity *entity,
+	struct v4l2_mbus_framefmt *format, unsigned int pad,
+	enum v4l2_subdev_format_whence which)
+{
+	struct v4l2_subdev_format fmt;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&fmt, 0, sizeof(fmt));
+	fmt.pad = pad;
+	fmt.which = which;
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_G_FMT, &fmt);
+	if (ret < 0)
+		return -errno;
+
+	*format = fmt.format;
+	return 0;
+}
+
+int v4l2_subdev_set_format(struct media_entity *entity,
+	struct v4l2_mbus_framefmt *format, unsigned int pad,
+	enum v4l2_subdev_format_whence which)
+{
+	struct v4l2_subdev_format fmt;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&fmt, 0, sizeof(fmt));
+	fmt.pad = pad;
+	fmt.which = which;
+	fmt.format = *format;
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_S_FMT, &fmt);
+	if (ret < 0)
+		return -errno;
+
+	*format = fmt.format;
+	return 0;
+}
+
+int v4l2_subdev_get_crop(struct media_entity *entity, struct v4l2_rect *rect,
+			 unsigned int pad, enum v4l2_subdev_format_whence which)
+{
+	struct v4l2_subdev_crop crop;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&crop, 0, sizeof(crop));
+	crop.pad = pad;
+	crop.which = which;
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_G_CROP, &crop);
+	if (ret < 0)
+		return -errno;
+
+	*rect = crop.rect;
+	return 0;
+}
+
+int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
+			 unsigned int pad, enum v4l2_subdev_format_whence which)
+{
+	struct v4l2_subdev_crop crop;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&crop, 0, sizeof(crop));
+	crop.pad = pad;
+	crop.which = which;
+	crop.rect = *rect;
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_S_CROP, &crop);
+	if (ret < 0)
+		return -errno;
+
+	*rect = crop.rect;
+	return 0;
+}
+
+int v4l2_subdev_get_frame_interval(struct media_entity *entity,
+				   struct v4l2_fract *interval)
+{
+	struct v4l2_subdev_frame_interval ival;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&ival, 0, sizeof(ival));
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_G_FRAME_INTERVAL, &ival);
+	if (ret < 0)
+		return -errno;
+
+	*interval = ival.interval;
+	return 0;
+}
+
+int v4l2_subdev_set_frame_interval(struct media_entity *entity,
+				   struct v4l2_fract *interval)
+{
+	struct v4l2_subdev_frame_interval ival;
+	int ret;
+
+	ret = v4l2_subdev_open(entity);
+	if (ret < 0)
+		return ret;
+
+	memset(&ival, 0, sizeof(ival));
+	ival.interval = *interval;
+
+	ret = ioctl(entity->fd, VIDIOC_SUBDEV_S_FRAME_INTERVAL, &ival);
+	if (ret < 0)
+		return -errno;
+
+	*interval = ival.interval;
+	return 0;
+}
diff --git a/src/subdev.h b/src/subdev.h
new file mode 100644
index 0000000..b5772e0
--- /dev/null
+++ b/src/subdev.h
@@ -0,0 +1,162 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ */
+
+#ifndef __SUBDEV_H__
+#define __SUBDEV_H__
+
+#include <linux/v4l2-subdev.h>
+
+struct media_entity;
+
+/**
+ * @brief Open a sub-device.
+ * @param entity - sub-device media entity.
+ *
+ * Open the V4L2 subdev device node associated with @a entity. The file
+ * descriptor is stored in the media_entity structure.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_open(struct media_entity *entity);
+
+/**
+ * @brief Close a sub-device.
+ * @param entity - sub-device media entity.
+ *
+ * Close the V4L2 subdev device node associated with the @a entity and opened by
+ * a previous call to v4l2_subdev_open() (either explicit or implicit).
+ */
+void v4l2_subdev_close(struct media_entity *entity);
+
+/**
+ * @brief Retrieve the format on a pad.
+ * @param entity - subdev-device media entity.
+ * @param format - format to be filled.
+ * @param pad - pad number.
+ * @param which - identifier of the format to get.
+ *
+ * Retrieve the current format on the @a entity @a pad and store it in the
+ * @a format structure.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to retrieve the try format stored
+ * in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to retrieve the current
+ * active format.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_get_format(struct media_entity *entity,
+	struct v4l2_mbus_framefmt *format, unsigned int pad,
+	enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Set the format on a pad.
+ * @param entity - subdev-device media entity.
+ * @param format - format.
+ * @param pad - pad number.
+ * @param which - identifier of the format to set.
+ *
+ * Set the format on the @a entity @a pad to @a format. The driver is allowed to
+ * modify the requested format, in which case @a format is updated with the
+ * modifications.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to set the try format stored in the
+ * file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to configure the device with an
+ * active format.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_set_format(struct media_entity *entity,
+	struct v4l2_mbus_framefmt *format, unsigned int pad,
+	enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Retrieve the crop rectangle on a pad.
+ * @param entity - subdev-device media entity.
+ * @param rect - crop rectangle to be filled.
+ * @param pad - pad number.
+ * @param which - identifier of the format to get.
+ *
+ * Retrieve the current crop rectangleon the @a entity @a pad and store it in
+ * the @a rect structure.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to retrieve the try crop rectangle
+ * stored in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to retrieve the
+ * current active crop rectangle.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_get_crop(struct media_entity *entity, struct v4l2_rect *rect,
+	unsigned int pad, enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Set the crop rectangle on a pad.
+ * @param entity - subdev-device media entity.
+ * @param rect - crop rectangle.
+ * @param pad - pad number.
+ * @param which - identifier of the format to set.
+ *
+ * Set the crop rectangle on the @a entity @a pad to @a rect. The driver is
+ * allowed to modify the requested rectangle, in which case @a rect is updated
+ * with the modifications.
+ *
+ * @a which is set to V4L2_SUBDEV_FORMAT_TRY to set the try crop rectangle
+ * stored in the file handle, of V4L2_SUBDEV_FORMAT_ACTIVE to configure the
+ * device with an active crop rectangle.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
+	unsigned int pad, enum v4l2_subdev_format_whence which);
+
+/**
+ * @brief Retrieve the frame interval on a sub-device.
+ * @param entity - subdev-device media entity.
+ * @param interval - frame interval to be filled.
+ *
+ * Retrieve the current frame interval on subdev @a entity and store it in the
+ * @a interval structure.
+ *
+ * Frame interval retrieving is usually supported only on devices at the
+ * beginning of video pipelines, such as sensors.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+
+int v4l2_subdev_get_frame_interval(struct media_entity *entity,
+	struct v4l2_fract *interval);
+
+/**
+ * @brief Set the frame interval on a sub-device.
+ * @param entity - subdev-device media entity.
+ * @param interval - frame interval.
+ *
+ * Set the frame interval on subdev @a entity to @a interval. The driver is
+ * allowed to modify the requested frame interval, in which case @a interval is
+ * updated with the modifications.
+ *
+ * Frame interval setting is usually supported only on devices at the beginning
+ * of video pipelines, such as sensors.
+ *
+ * @return 0 on success, or a negative error code on failure.
+ */
+int v4l2_subdev_set_frame_interval(struct media_entity *entity,
+	struct v4l2_fract *interval);
+
+#endif
+
diff --git a/src/tools.h b/src/tools.h
new file mode 100644
index 0000000..0a0a948
--- /dev/null
+++ b/src/tools.h
@@ -0,0 +1,27 @@
+/*
+ * Media controller test application
+ *
+ * Copyright (C) 2010 Ideas on board SPRL <laurent.pinchart@ideasonboard.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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __TOOLS_H__
+#define __TOOLS_H__
+
+#define ARRAY_SIZE(array)	(sizeof(array) / sizeof((array)[0]))
+
+#endif /* __TOOLS_H__ */
+