diff mbox series

[1/4] dt-bindings: nvmem: layouts: add U-Boot environment variables layout

Message ID 20231218133722.16150-1-zajec5@gmail.com
State Superseded
Headers show
Series [1/4] dt-bindings: nvmem: layouts: add U-Boot environment variables layout | expand

Commit Message

Rafał Miłecki Dec. 18, 2023, 1:37 p.m. UTC 
From: Rafał Miłecki <rafal@milecki.pl>

U-Boot env data is a way of storing firmware variables. It's a format
that can be used of top of various storage devices. Its binding should
be an NVMEM layout instead of a standalone device.

This patch adds layout binding which allows using it on top of MTD NVMEM
device as well as any other. At the same time it deprecates the old
combined binding.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 .../bindings/nvmem/layouts/u-boot,env.yaml    | 55 +++++++++++++++++++
 .../devicetree/bindings/nvmem/u-boot,env.yaml |  6 ++
 2 files changed, 61 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml

Comments

Miquel Raynal Dec. 18, 2023, 2:02 p.m. UTC | #1 
Hi Rafał,

zajec5@gmail.com wrote on Mon, 18 Dec 2023 14:37:21 +0100:

> From: Rafał Miłecki <rafal@milecki.pl>
> 
> 1. Use nvmem_dev_size() and nvmem_device_read() to make this driver less
>    mtd dependent
> 2. Use nvmem_add_one_cell() to simplify adding NVMEM cells
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
new file mode 100644
index 000000000000..3a7ec02b3535
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/layouts/u-boot,env.yaml
@@ -0,0 +1,55 @@ 
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/layouts/u-boot,env.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVMEM layout of U-Boot environment variables
+
+maintainers:
+  - Rafał Miłecki <rafal@milecki.pl>
+
+description:
+  U-Boot uses environment variables to store device parameters and
+  configuration. They may be used for booting process, setup or keeping end user
+  info.
+
+  Data is stored using U-Boot specific formats (variant specific header and NUL
+  separated key-value pairs).
+
+properties:
+  compatible:
+    oneOf:
+      - description: A standalone env data block
+        const: u-boot,env
+      - description: Two redundant blocks with active one flagged
+        const: u-boot,env-redundant-bool
+      - description: Two redundant blocks with active having higher counter
+        const: u-boot,env-redundant-count
+      - description: Broadcom's variant with custom header
+        const: brcm,env
+
+additionalProperties: false
+
+examples:
+  - |
+    partitions {
+        compatible = "fixed-partitions";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        partition@0 {
+            reg = <0x0 0x40000>;
+            label = "u-boot";
+            read-only;
+        };
+
+        partition@40000 {
+            reg = <0x40000 0x10000>;
+            label = "u-boot-env";
+
+            nvmem-layout {
+                compatible = "u-boot,env";
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
index 68214b96f5c9..fd95e611322d 100644
--- a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
+++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
@@ -26,9 +26,15 @@  description: |
 
   Variables can be defined as NVMEM device subnodes.
 
+  Introduction of NVMEM layouts exposed a limitation of this binding design.
+  Description of NVMEM data content should be separated from NVMEM devices.
+  Since the introduction of U-Boot env data layout this binding is deprecated.
+
 maintainers:
   - Rafał Miłecki <rafal@milecki.pl>
 
+deprecated: true
+
 properties:
   compatible:
     oneOf: