[PATCH 6/6] mtd: ofpart: add compatible check for child nodes

Josh Wu josh.wu at atmel.com
Wed Jul 3 05:50:34 EDT 2013

In case that the nand device will support some features like Nand Flash
Controller, we want to make the sub feature as a sub node of nand device.

Use such organization it is easy to enable/disable feature, also it is back
compatible and more readable.

If the sub-node has a compatible property then it is a driver not partition.

Signed-off-by: Josh Wu <josh.wu at atmel.com>
v3 --> v4:
  - remove the 'len' parameter, just use NULL.
  - refine the commit message.
  - also add a NOTE in devicetree/bindings/mtd/partition.txt.

 .../devicetree/bindings/mtd/partition.txt          |    1 +
 drivers/mtd/ofpart.c                               |   13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt
index 9315ac9..8e5557d 100644
--- a/Documentation/devicetree/bindings/mtd/partition.txt
+++ b/Documentation/devicetree/bindings/mtd/partition.txt
@@ -4,6 +4,7 @@ Partitions can be represented by sub-nodes of an mtd device. This can be used
 on platforms which have strong conventions about which portions of a flash are
 used for what purposes, but which don't use an on-flash partition table such
 as RedBoot.
+NOTE: if the sub-node has a compatible string, then it is not a partition.
 #address-cells & #size-cells must both be present in the mtd device. There are
 two valid values for both:
diff --git a/drivers/mtd/ofpart.c b/drivers/mtd/ofpart.c
index 553d6d6..30fcea1 100644
--- a/drivers/mtd/ofpart.c
+++ b/drivers/mtd/ofpart.c
@@ -20,6 +20,10 @@
 #include <linux/slab.h>
 #include <linux/mtd/partitions.h>
+static bool node_has_compatible(struct device_node *pp)
+	return of_get_property(pp, "compatible", NULL);
 static int parse_ofpart_partitions(struct mtd_info *master,
 				   struct mtd_partition **pparts,
 				   struct mtd_part_parser_data *data)
@@ -40,8 +44,12 @@ static int parse_ofpart_partitions(struct mtd_info *master,
 	/* First count the subnodes */
 	pp = NULL;
 	nr_parts = 0;
-	while ((pp = of_get_next_child(node, pp)))
+	while ((pp = of_get_next_child(node, pp))) {
+		if (node_has_compatible(pp))
+			continue;
+	}
 	if (nr_parts == 0)
 		return 0;
@@ -57,6 +65,9 @@ static int parse_ofpart_partitions(struct mtd_info *master,
 		int len;
 		int a_cells, s_cells;
+		if (node_has_compatible(pp))
+			continue;
 		reg = of_get_property(pp, "reg", &len);
 		if (!reg) {

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