V4L2 subdev crop support

Extend the V4L2 media bus format syntax to support an optional crop
rectangle. If specified, the crop rectangle is set on the subdev pad.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

4 files changed, 147 insertions, 12 deletions

diff --git a/main.c b/main.c
index c59b633..9b8951a 100644
--- a/main.c
+++ b/main.c
@@ -203,8 +203,36 @@ static int parse_format(struct v4l2_mbus_framefmt *format, const char *p, char *
 	return 0;
 }
 
+static int parse_crop(struct v4l2_rect *crop, const char *p, char **endp)
+{
+	char *end;
+
+	for (; isspace(*p); ++p);
+
+	crop->left = strtoul(p, &end, 10);
+	if (*end != ',')
+		return -EINVAL;
+
+	p = end + 1;
+	crop->top = strtoul(p, &end, 10);
+	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 struct media_entity_pad *parse_pad_format(struct media_device *media,
-	struct v4l2_mbus_framefmt *format, const char *p, char **endp)
+	struct v4l2_mbus_framefmt *format, struct v4l2_rect *crop,
+	const char *p, char **endp)
 {
 	struct media_entity_pad *pad;
 	char *end;
@@ -225,10 +253,18 @@ static struct media_entity_pad *parse_pad_format(struct media_device *media,
 		return NULL;
 
 	for (p = end; isspace(*p); p++);
-	if (*p++ != ']')
+	if (*p != ']') {
+		ret = parse_crop(crop, p, &end);
+		if (ret < 0)
+			return NULL;
+
+		for (p = end; isspace(*p); p++);
+	}
+
+	if (*p != ']')
 		return NULL;
 
-	*endp = (char *)p;
+	*endp = (char *)p + 1;
 	return pad;
 }
 
@@ -253,23 +289,55 @@ static int set_format(struct media_entity_pad *pad, struct v4l2_mbus_framefmt *f
 	return 0;
 }
 
+static int set_crop(struct media_entity_pad *pad, struct v4l2_rect *crop)
+{
+	int ret;
+
+	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)", 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 setup_format(struct media_device *media, const char *p, char **endp)
 {
 	struct v4l2_mbus_framefmt format;
 	struct media_entity_pad *pad;
+	struct v4l2_rect crop = { -1, -1, -1, -1 };
 	unsigned int i;
 	char *end;
 	int ret;
 
-	pad = parse_pad_format(media, &format, p, &end);
+	pad = parse_pad_format(media, &format, &crop, p, &end);
 	if (pad == NULL) {
 		printf("Unable to parse format\n");
 		return -EINVAL;
 	}
 
 	ret = set_format(pad, &format);
-	if (ret < 0)
+	if (ret < 0) {
+		printf("Unable to set format\n");
 		return ret;
+	}
+
+	if (crop.left != -1 && crop.top != -1) {
+		ret = set_crop(pad, &crop);
+		if (ret < 0) {
+			printf("Unable to set crop rectangle\n");
+			return ret;
+		}
+	}
 
 	/* If the pad is an output pad, automatically set the same format on
 	 * the remote subdev input pads, if any.
@@ -301,10 +369,8 @@ static int setup_formats(struct media_device *media, const char *p)
 
 	do {
 		ret = setup_format(media, p, &end);
-		if (ret < 0) {
-			printf("Unable to parse format\n");
+		if (ret < 0)
 			return ret;
-		}
 
 		p = end + 1;
 	} while (*end == ',');
diff --git a/options.c b/options.c
index 5e4c9f7..69ff9d5 100644
--- a/options.c
+++ b/options.c
@@ -30,19 +30,39 @@ struct media_options media_opts = {
 	.devname = MEDIA_DEVNAME_DEFAULT,
 };
 
-static void usage(const char *argv0)
+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, --formats		Comma-separated list of formats to setup\n");
-	printf("-h, --help		Show this help screen\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 ], ']' ;\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("where the fields are\n");
+	printf("\tentity number   Entity numeric identifier\n");
+	printf("\tentity name     Entify 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");
 }
 
 #define OPT_PRINT_DOT	256
@@ -65,7 +85,7 @@ int parse_cmdline(int argc, char **argv)
 	int opt;
 
 	if (argc == 1) {
-		usage(argv[0]);
+		usage(argv[0], 0);
 		return 1;
 	}
 
@@ -85,7 +105,7 @@ int parse_cmdline(int argc, char **argv)
 			break;
 
 		case 'h':
-			usage(argv[0]);
+			usage(argv[0], 1);
 			exit(0);
 
 		case 'i':
diff --git a/subdev.c b/subdev.c
index c35b5b4..ac14324 100644
--- a/subdev.c
+++ b/subdev.c
@@ -133,3 +133,48 @@ int v4l2_subdev_set_format(struct media_entity *entity,
 	return 0;
 }
 
+int v4l2_subdev_get_crop(struct media_entity *entity, struct v4l2_rect *rect,
+			 unsigned int pad, enum v4l2_subdev_format which)
+{
+	struct v4l2_subdev_pad_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 which)
+{
+	struct v4l2_subdev_pad_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;
+}
+
diff --git a/subdev.h b/subdev.h
index c431271..e3106e6 100644
--- a/subdev.h
+++ b/subdev.h
@@ -34,6 +34,10 @@ int v4l2_subdev_get_format(struct media_entity *entity,
 int v4l2_subdev_set_format(struct media_entity *entity,
 	struct v4l2_mbus_framefmt *format, unsigned int pad,
 	enum v4l2_subdev_format which);
+int v4l2_subdev_get_crop(struct media_entity *entity, struct v4l2_rect *rect,
+	unsigned int pad, enum v4l2_subdev_format which);
+int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
+	unsigned int pad, enum v4l2_subdev_format which);
 
 #endif