[PATCH] dt-bindings: nvmem: layouts: add fixed-layout

From: Rafał Miłecki
Date: Thu Mar 09 2023 - 04:35:16 EST


From: Rafał Miłecki <rafal@xxxxxxxxxx>

With the introduction of NVMEM layouts I believe we should prefer and
support describing all NVMEM devices content in the "nvmem-layout" node.
Inluding fixed NVMEM cells (those with hardcoded offset & size).

This seems to be cleaner design and more explicit.

Introduce a binding allowing fixed NVMEM cells as a type of layout.

Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
---
.../bindings/nvmem/layouts/fixed-layout.yaml | 52 +++++++++++++++++++
.../bindings/nvmem/layouts/nvmem-layout.yaml | 1 +
2 files changed, 53 insertions(+)
create mode 100644 Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml

diff --git a/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
new file mode 100644
index 000000000000..7eb86c999a5e
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/layouts/fixed-layout.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/layouts/fixed-layout.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVMEM layout for fixed NVMEM cells
+
+description:
+ Many NVMEM devices have hardcoded cells layout (offset and size of specific
+ NVMEM content doesn't change).
+
+ This binding allows defining such cells using NVMEM layout. It can be used on
+ top of any NVMEM device.
+
+maintainers:
+ - Rafał Miłecki <rafal@xxxxxxxxxx>
+
+properties:
+ compatible:
+ const: fixed-layout
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 1
+
+patternProperties:
+ "@[a-f0-9]+$":
+ type: object
+ description: NVMEM cell
+ properties:
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ nvmem-layout {
+ compatible = "fixed-layout";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ calibration@4000 {
+ reg = <0x4000 0x100>;
+ };
+ };
diff --git a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
index 8512ee538c4c..03da7848c713 100644
--- a/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
+++ b/Documentation/devicetree/bindings/nvmem/layouts/nvmem-layout.yaml
@@ -18,6 +18,7 @@ description: |
perform their parsing. The nvmem-layout container is here to describe these.

oneOf:
+ - $ref: fixed-layout.yaml
- $ref: kontron,sl28-vpd.yaml
- $ref: onie,tlv-layout.yaml

--
2.34.1