From: Brian Norris Date: Thu, 3 Dec 2015 22:47:32 +0000 (-0800) Subject: doc: dt: mtd: partitions: add compatible property to "partitions" node X-Git-Tag: v5.15~14556^2 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=e488ca9f8d4f62c2dc36bfa5c32f68e7f05ab381;p=mirror_ubuntu-kernels.git doc: dt: mtd: partitions: add compatible property to "partitions" node As noted here [1], there are potentially future conflicts if we try to use MTD's "partitions" subnode to describe anything besides just the fixed-in-the-device-tree partitions currently described in this document. Particularly, there was a proposal to use this node for the AFS parser too. It can pose a (small) problem to try to differentiate the following nodes: // using binding as currently specified partitions { #address-cells = ; #size-cells = ; partition@0 { ...; }; }; and // proposed future binding partitions { compatible = "arm,arm-flash-structure"; }; It's especially difficult if other uses of this node start having subnodes. So, since the "partitions" node is new in v4.4, let's fixup the binding before release so that it requires a compatible property, so it's much clearer to distinguish. e.g.: // proposed partitions { compatible = "fixed-partitions"; #address-cells = ; #size-cells = ; partition@0 { ...; }; }; [1] Subject: "mtd: create a partition type device tree binding" http://lkml.kernel.org/g/20151113220039.GA74382@google.com http://lists.infradead.org/pipermail/linux-mtd/2015-November/063355.html http://lists.infradead.org/pipermail/linux-mtd/2015-November/063364.html Cc: Michal Suchanek Signed-off-by: Brian Norris Acked-by: Rob Herring --- diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt index f1e2a02381a4..1c63e40659fc 100644 --- a/Documentation/devicetree/bindings/mtd/partition.txt +++ b/Documentation/devicetree/bindings/mtd/partition.txt @@ -6,7 +6,9 @@ used for what purposes, but which don't use an on-flash partition table such as RedBoot. The partition table should be a subnode of the mtd node and should be named -'partitions'. Partitions are defined in subnodes of the partitions node. +'partitions'. This node should have the following property: +- compatible : (required) must be "fixed-partitions" +Partitions are then defined in subnodes of the partitions node. For backwards compatibility partitions as direct subnodes of the mtd device are supported. This use is discouraged. @@ -36,6 +38,7 @@ Examples: flash@0 { partitions { + compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <1>; @@ -53,6 +56,7 @@ flash@0 { flash@1 { partitions { + compatible = "fixed-partitions"; #address-cells = <1>; #size-cells = <2>; @@ -66,6 +70,7 @@ flash@1 { flash@2 { partitions { + compatible = "fixed-partitions"; #address-cells = <2>; #size-cells = <2>; diff --git a/drivers/mtd/ofpart.c b/drivers/mtd/ofpart.c index 3e9c5857c991..9ed6038e47d2 100644 --- a/drivers/mtd/ofpart.c +++ b/drivers/mtd/ofpart.c @@ -55,6 +55,9 @@ static int parse_ofpart_partitions(struct mtd_info *master, master->name, mtd_node->full_name); ofpart_node = mtd_node; dedicated = false; + } else if (!of_device_is_compatible(ofpart_node, "fixed-partitions")) { + /* The 'partitions' subnode might be used by another parser */ + return 0; } /* First count the subnodes */