[PATCH 2/3] dt-bindings: nvmem: add U-Boot environment variables binding

[Rafał Miłecki]

From: Rafał Miłecki <rafal at milecki.pl>

This binding allows describing a (part of) MTD device (partition) that
contains a block with environment variables. Operating system usually
needs to parse that block to read variables values that may affect
booting process & device configuration.

Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
 .../devicetree/bindings/nvmem/u-boot,env.yaml | 56 +++++++++++++++++++
 MAINTAINERS                                   |  5 ++
 2 files changed, 61 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/u-boot,env.yaml

diff --git a/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
new file mode 100644
index 000000000000..0f808868fff3
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/u-boot,env.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: U-Boot environment variables
+
+description: |
+  U-Boot uses environment variables to store device parameters and
+  configuration. They may be used for booting process, setup or keeping end user
+  interesting info.
+
+  Data is stored on flash partition in a U-Boot specific format (CRC32 and NUL
+  separated key-value pairs).
+
+  This binding allows specifying data location and format (default one or vendor
+  specific).
+
+maintainers:
+  - Rafał Miłecki <rafal at milecki.pl>
+
+allOf:
+  - $ref: nvmem.yaml#
+
+properties:
+  compatible:
+    enum:
+      - u,boot,env
+      - brcm,env
+
+  reg:
+    maxItems: 1
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    partitions {
+        compatible = "fixed-partitions";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        partition at 0 {
+            label = "uboot";
+            reg = <0x0 0x100000>;
+
+            #address-cells = <1>;
+            #size-cells = <1>;
+
+            nvmem at 10000 {
+                compatible = "u,boot,env";
+                reg = <0x10000 0x10000>;
+            };
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 67558097bb66..271c29c84c7d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19624,6 +19624,11 @@ W:	http://linuxtv.org
 T:	git git://linuxtv.org/media_tree.git
 F:	drivers/media/pci/tw686x/
 
+U-BOOT ENVIRONMENT VARIABLES
+M:	Rafał Miłecki <rafal at milecki.pl>
+S:	Maintained
+F:	Documentation/devicetree/bindings/nvmem/u-boot,env.yaml
+
 UACCE ACCELERATOR FRAMEWORK
 M:	Zhangfei Gao <zhangfei.gao at linaro.org>
 M:	Zhou Wang <wangzhou1 at hisilicon.com>
-- 
2.31.1