This makes it possible to open a ubi layer in device tree, this is
helpful when the rootfs is on a ubi layer. It loops though all mtd
partitions and mounts the partition which is compatible with
"ubi,volume". The same was only possible with kernel command line
arguments before.
Signed-off-by: Hauke Mehrtens <hauke@xxxxxxxxxx>
---
Documentation/devicetree/bindings/mtd/ubi.txt | 33 ++++++++++++++
drivers/mtd/ubi/block.c | 63 +++++++++++++++++++++++++++
2 files changed, 96 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mtd/ubi.txt
diff --git a/Documentation/devicetree/bindings/mtd/ubi.txt b/Documentation/devicetree/bindings/mtd/ubi.txt
new file mode 100644
index 0000000..5fcd47e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ubi.txt
@@ -0,0 +1,33 @@
+UBI - Unsorted block images
+
+Describe of a UBI layer in device tree.
+
+ - compatible: "ubi,device", This marks a partition that contains
+ a ubi layer.
+ - vid_hdr_offs: Optional parameter specifies UBI VID header position
+ to be used by UBI. (default value if 0)
+ - max_beb_per1024: Optional parameter specifies the maximum expected bad
+ eraseblock per 1024 eraseblocks.
+ (default value CONFIG_MTD_UBI_BEB_LIMIT)
+ -ubi_num: Optional parameter specifies UBI device number
+ which have to be assigned to the newly created UBI
+ device (assigned automatically by default)
+
+Example:
+
+partitions {
+ compatible = "fixed-partitions";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ label = "uboot";
+ reg = <0x00000 0x100000>;
+ };
+
+ partition@1c0000 {
+ label = "system_sw";
+ reg = <0x1c0000 0xc800000>;
+ compatible = "ubi,device";
+ };
+};
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index ebf46ad..5ed390d 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -1,6 +1,7 @@
/*
* Copyright (c) 2014 Ezequiel Garcia
* Copyright (c) 2011 Free Electrons
+ * Copyright (c) 2016 Hauke Mehrtens <hauke@xxxxxxxxxx>
*
* Driver parameter handling strongly based on drivers/mtd/ubi/build.c
* Copyright (c) International Business Machines Corp., 2006
@@ -41,6 +42,7 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
+#include <linux/of.h>
#include <linux/slab.h>
#include <linux/mtd/ubi.h>
#include <linux/workqueue.h>
@@ -628,6 +630,64 @@ static void __init ubiblock_create_from_param(void)
}
}
+static void __init ubiblock_create_from_device_tree(void)
+{
+ int ubi_num;
+ const char *name;
+ u32 mode;
+ struct ubi_device *ubi;
+ struct ubi_volume_desc *desc;
+ struct ubi_volume_info vi;
+ struct mtd_info *mtd;
+ struct device_node *volume;
+ int ret;
+
+ for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) {
+ ubi = ubi_get_device(ubi_num);
+ if (!ubi)
+ continue;
+ mtd = ubi->mtd;
+ if (!mtd || !of_device_is_compatible(mtd->dev.of_node,
+ "ubi,device")) {
+ ubi_put_device(ubi);
+ continue;
+ }
+
+ for_each_child_of_node(mtd->dev.of_node, volume) {
+ if (!of_device_is_compatible(volume, "ubi,volume"))
+ continue;
+
+ ret = of_property_read_string(volume, "name", &name);
+ if (ret)
+ continue;
+
+ ret = of_property_read_u32(volume, "ubi-mode", &mode);
+ if (ret)
+ continue;
+
+ desc = ubi_open_volume_nm(ubi_num, name, mode);
+ if (IS_ERR(desc)) {
+ pr_err(
+ "UBI: block: can't open volume %s on ubi%d, err=%ld",
+ name, ubi_num, PTR_ERR(desc));
+ continue;
+ }
+
+ ubi_get_volume_info(desc, &vi);
+ ubi_close_volume(desc);
+
+ ret = ubiblock_create(&vi);
+ if (ret) {
+ pr_err(
+ "UBI: block: can't add '%s' volume on ubi%d, err=%d",
+ vi.name, ubi_num, ret);
+ continue;
+ }
+ }
+ ubi_put_device(ubi);
+ }
+}
+
static void ubiblock_remove_all(void)
{
struct ubiblock *next;
@@ -658,6 +718,9 @@ int __init ubiblock_init(void)
*/
ubiblock_create_from_param();
+ /* Attach block devices from device tree */
+ ubiblock_create_from_device_tree();
+
/*
* Block devices are only created upon user requests, so we ignore
* existing volumes.
--
2.8.1
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