[PATCH RFC 10/13] v4l2-of: Support variable length of data-lanes property

[Sylwester Nawrocki]

Based on code from Guennadi Liakhovetski <g.liakhovetski at gmx.de>.

Add data_lanes property which relects the number of active data lanes,
that is length of the data-lanes array. Previously we assumed the
data-lanes array had fixed length which doesn't match the binding
semantics.

Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
 drivers/media/v4l2-core/v4l2-of.c |   15 +++++++++++----
 include/media/v4l2-of.h           |    1 +
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
index f45d64b..4e6658c 100644
--- a/drivers/media/v4l2-core/v4l2-of.c
+++ b/drivers/media/v4l2-core/v4l2-of.c
@@ -33,6 +33,7 @@ void v4l2_of_parse_link(const struct device_node *node,
 	unsigned int v;
 	u32 data_lanes[ARRAY_SIZE(link->mipi_csi_2.data_lanes)];
 	bool data_lanes_present;
+	struct property *prop;
 
 	memset(link, 0, sizeof(*link));
 
@@ -83,10 +84,16 @@ void v4l2_of_parse_link(const struct device_node *node,
 	if (!of_property_read_u32(node, "clock-lanes", &v))
 		link->mipi_csi_2.clock_lane = v;
 
-	if (!of_property_read_u32_array(node, "data-lanes", data_lanes,
-					ARRAY_SIZE(data_lanes))) {
-		int i;
-		for (i = 0; i < ARRAY_SIZE(data_lanes); i++)
+	prop = of_find_property(node, "data-lanes", NULL);
+	if (prop) {
+		int i = 0;
+		const __be32 *lane = NULL;
+		do {
+			lane = of_prop_next_u32(prop, lane, &data_lanes[i]);
+		} while (lane && i++ < ARRAY_SIZE(data_lanes));
+
+		link->mipi_csi_2.num_data_lanes = i;
+		while (i--)
 			link->mipi_csi_2.data_lanes[i] = data_lanes[i];
 		data_lanes_present = true;
 	} else {
diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h
index 6fafedb..ccb1ebe 100644
--- a/include/media/v4l2-of.h
+++ b/include/media/v4l2-of.h
@@ -33,6 +33,7 @@ struct v4l2_of_link {
 		struct {
 			unsigned char data_lanes[4];
 			unsigned char clock_lane;
+			unsigned short num_data_lanes;
 		} mipi_csi_2;
 	};
 };
-- 
1.7.9.5