[PATCH v2] mtd: ofpart: support partitions of 4 GB and larger

Aaron Sierra
2013-02-21T22:29:51Z

From: Joe Schaack <jschaack@xes-inc.com>

Previously, partitions were limited to less than 4 GB in size because
the address and size were read as 32-bit values. Add support for 64-bit
values to support devices of 4 GB and larger.

Signed-off-by: Joe Schaack <jschaack@xes-inc.com>
Signed-off-by: Nate Case <ncase@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
---
.../devicetree/bindings/mtd/partition.txt | 36 ++++++++++++++++++--
drivers/mtd/ofpart.c | 7 ++--
2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/mtd/partition.txt b/Documentation/devicetree/bindings/mtd/partition.txt
index 6e1f61f..8f354bc 100644
--- a/Documentation/devicetree/bindings/mtd/partition.txt
+++ b/Documentation/devicetree/bindings/mtd/partition.txt
@@ -5,8 +5,12 @@ 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.

-#address-cells & #size-cells must both be present in the mtd device and be
-equal to 1.
+#address-cells & #size-cells must both be present in the mtd device. There are
+two valid values for both:
+<1>: for partitions that require a single 32-bit cell to represent their
+ size/address (aka the value is below 4 GB)
+<2>: for partitions that require two 32-bit cells to represent their
+ size/address (aka the value is 4 GB or greater).

Required properties:
- reg : The partition's offset and size within the mtd bank.
@@ -36,3 +40,31 @@ flash@0 {
reg = <0x0100000 0x200000>;
};
};
+
+flash@1 {
+ #address-cells = <1>;
+ #size-cells = <2>;
+
+ /* a 4 GB partition */
+ partition@0 {
+ label = "filesystem";
+ reg = <0x00000000 0x1 0x00000000>;
+ };
+};
+
+flash@2 {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ /* an 8 GB partition */
+ partition@0 {
+ label = "filesystem #1";
+ reg = <0x0 0x00000000 0x2 0x00000000>;
+ };
+
+ /* a 4 GB partition */
+ partition@200000000 {
+ label = "filesystem #2";
+ reg = <0x2 0x00000000 0x1 0x00000000>;
+ };
+};
diff --git a/drivers/mtd/ofpart.c b/drivers/mtd/ofpart.c
index 30bd907..553d6d6 100644
--- a/drivers/mtd/ofpart.c
+++ b/drivers/mtd/ofpart.c
@@ -55,6 +55,7 @@ static int parse_ofpart_partitions(struct mtd_info *master,
while ((pp = of_get_next_child(node, pp))) {
const __be32 *reg;
int len;
+ int a_cells, s_cells;

reg = of_get_property(pp, "reg", &len);
if (!reg) {
@@ -62,8 +63,10 @@ static int parse_ofpart_partitions(struct mtd_info *master,
continue;
}

- (*pparts)[i].offset = be32_to_cpu(reg[0]);
- (*pparts)[i].size = be32_to_cpu(reg[1]);
+ a_cells = of_n_addr_cells(pp);
+ s_cells = of_n_size_cells(pp);
+ (*pparts)[i].offset = of_read_number(reg, a_cells);
+ (*pparts)[i].size = of_read_number(reg + a_cells, s_cells);

partname = of_get_property(pp, "label", &len);
if (!partname)
--
1.7.9.5