V4L2 subdev frame interval support

Extend the V4L2 media bus format syntax to support an optional frame interval
value. If specified, the frame interval is set on the subdev.

Signed-off-by: Todor Tomov <ttomov@mm-sol.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

4 files changed, 85 insertions, 4 deletions

diff --git a/main.c b/main.c
index 9b8951a..96b7ca1 100644
--- a/main.c
+++ b/main.c
@@ -230,9 +230,28 @@ static int parse_crop(struct v4l2_rect *crop, const char *p, char **endp)
 	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_entity_pad *parse_pad_format(struct media_device *media,
 	struct v4l2_mbus_framefmt *format, struct v4l2_rect *crop,
-	const char *p, char **endp)
+	struct v4l2_fract *interval, const char *p, char **endp)
 {
 	struct media_entity_pad *pad;
 	char *end;
@@ -253,7 +272,7 @@ static struct media_entity_pad *parse_pad_format(struct media_device *media,
 		return NULL;
 
 	for (p = end; isspace(*p); p++);
-	if (*p != ']') {
+	if (isdigit(*p)) {
 		ret = parse_crop(crop, p, &end);
 		if (ret < 0)
 			return NULL;
@@ -261,6 +280,14 @@ static struct media_entity_pad *parse_pad_format(struct media_device *media,
 		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;
 
@@ -310,16 +337,37 @@ static int set_crop(struct media_entity_pad *pad, struct v4l2_rect *crop)
 	return 0;
 }
 
+static int set_frame_interval(struct media_entity *entity, struct v4l2_fract *interval)
+{
+	int ret;
+
+	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;
 	struct media_entity_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, p, &end);
+	pad = parse_pad_format(media, &format, &crop, &interval, p, &end);
 	if (pad == NULL) {
 		printf("Unable to parse format\n");
 		return -EINVAL;
@@ -339,6 +387,14 @@ static int setup_format(struct media_device *media, const char *p, char **endp)
 		}
 	}
 
+	if (interval.numerator != 0) {
+		ret = set_frame_interval(pad->entity, &interval);
+		if (ret < 0) {
+			printf("Unable to set frame interval\n");
+			return ret;
+		}
+	}
+
 	/* If the pad is an output pad, automatically set the same format on
 	 * the remote subdev input pads, if any.
 	 */
diff --git a/options.c b/options.c
index 69ff9d5..6fd2daf 100644
--- a/options.c
+++ b/options.c
@@ -50,11 +50,12 @@ static void usage(const char *argv0, int verbose)
 	printf("\n");
 	printf("Links and formats are defined as\n");
 	printf("\tlink            = pad, '->', pad, '[', flags, ']' ;\n");
-	printf("\tformat          = pad, '[', fcc, ' ', size, [ ' ', crop ], ']' ;\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     Entify name (string) \n");
@@ -63,6 +64,8 @@ static void usage(const char *argv0, int verbose)
 	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
diff --git a/subdev.c b/subdev.c
index ac14324..40b2506 100644
--- a/subdev.c
+++ b/subdev.c
@@ -178,3 +178,23 @@ int v4l2_subdev_set_crop(struct media_entity *entity, struct v4l2_rect *rect,
 	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/subdev.h b/subdev.h
index e3106e6..7b65411 100644
--- a/subdev.h
+++ b/subdev.h
@@ -38,6 +38,8 @@ 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);
+int v4l2_subdev_set_frame_interval(struct media_entity *entity,
+	struct v4l2_fract *interval);
 
 #endif