From dcc1f2aebb01437a2b43125ca986c7ffc5e702e7 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Tue, 20 May 2014 16:54:27 +0200
Subject: Add field support for the media bus format

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/main.c       |  3 +++
 src/v4l2subdev.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/v4l2subdev.h | 25 ++++++++++++++++++++++-
 3 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/src/main.c b/src/main.c
index 6f980b4..57618d6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -63,6 +63,9 @@ static void v4l2_subdev_print_format(struct media_entity *entity,
 	       v4l2_subdev_pixelcode_to_string(format.code),
 	       format.width, format.height);
 
+	if (format.field)
+		printf(" field:%s", v4l2_subdev_field_to_string(format.field));
+
 	ret = v4l2_subdev_get_selection(entity, &rect, pad,
 					V4L2_SEL_TGT_CROP_BOUNDS,
 					which);
diff --git a/src/v4l2subdev.c b/src/v4l2subdev.c
index 6c7f9ec..f55de9d 100644
--- a/src/v4l2subdev.c
+++ b/src/v4l2subdev.c
@@ -401,6 +401,24 @@ static struct media_pad *v4l2_subdev_parse_pad_format(
 			continue;
 		}
 
+		if (strhazit("field:", &p)) {
+			enum v4l2_field field;
+
+			for (end = (char *)p; isalpha(*end) || *end == '-'; ++end);
+
+			field = v4l2_subdev_string_to_field(p, end - p);
+			if (field == (enum v4l2_field)-1) {
+				media_dbg(media, "Invalid field value '%*s'\n", end - p, p);
+				*endp = (char *)p;
+				return NULL;
+			}
+
+			format->field = field;
+
+			p = end;
+			continue;
+		}
+
 		/*
 		 * Backward compatibility: crop rectangles can be specified
 		 * implicitly without the 'crop:' property name.
@@ -683,3 +701,47 @@ enum v4l2_mbus_pixelcode v4l2_subdev_string_to_pixelcode(const char *string,
 
 	return mbus_formats[i].code;
 }
+
+static struct {
+	const char *name;
+	enum v4l2_field field;
+} fields[] = {
+	{ "any", V4L2_FIELD_ANY },
+	{ "none", V4L2_FIELD_NONE },
+	{ "top", V4L2_FIELD_TOP },
+	{ "bottom", V4L2_FIELD_BOTTOM },
+	{ "interlaced", V4L2_FIELD_INTERLACED },
+	{ "seq-tb", V4L2_FIELD_SEQ_TB },
+	{ "seq-bt", V4L2_FIELD_SEQ_BT },
+	{ "alternate", V4L2_FIELD_ALTERNATE },
+	{ "interlaced-tb", V4L2_FIELD_INTERLACED_TB },
+	{ "interlaced-bt", V4L2_FIELD_INTERLACED_BT },
+};
+
+const char *v4l2_subdev_field_to_string(enum v4l2_field field)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(fields); ++i) {
+		if (fields[i].field == field)
+			return fields[i].name;
+	}
+
+	return "unknown";
+}
+
+enum v4l2_field v4l2_subdev_string_to_field(const char *string,
+					    unsigned int length)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(fields); ++i) {
+		if (strncmp(fields[i].name, string, length) == 0)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(fields))
+		return (enum v4l2_field)-1;
+
+	return fields[i].field;
+}
diff --git a/src/v4l2subdev.h b/src/v4l2subdev.h
index 5d55482..4589739 100644
--- a/src/v4l2subdev.h
+++ b/src/v4l2subdev.h
@@ -194,7 +194,7 @@ const char *v4l2_subdev_pixelcode_to_string(enum v4l2_mbus_pixelcode code);
 /**
  * @brief Parse string to media bus pixel code.
  * @param string - input string
- * @param lenght - length of the string
+ * @param length - length of the string
  *
  * Parse human readable string @a string to an media bus pixel code.
  *
@@ -202,4 +202,27 @@ const char *v4l2_subdev_pixelcode_to_string(enum v4l2_mbus_pixelcode code);
  */
 enum v4l2_mbus_pixelcode v4l2_subdev_string_to_pixelcode(const char *string,
 							 unsigned int length);
+
+/**
+ * @brief Convert a field order to string.
+ * @param field - field order
+ *
+ * Convert field order @a field to a human-readable string.
+ *
+ * @return A pointer to a string on success, NULL on failure.
+ */
+const char *v4l2_subdev_field_to_string(enum v4l2_field field);
+
+/**
+ * @brief Parse string to field order.
+ * @param string - input string
+ * @param length - length of the string
+ *
+ * Parse human readable string @a string to field order.
+ *
+ * @return field order on success, -1 on failure.
+ */
+enum v4l2_field v4l2_subdev_string_to_field(const char *string,
+					    unsigned int length);
+
 #endif
-- 
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