[PATCH v2 1/5] dt-bindings: nvmem: Add bindings for rmem driver

Nicolas Saenz Julienne nsaenzjulienne at suse.de
Fri Dec 18 10:43:16 EST 2020


Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.

Introduce the dt-bindings to nvmem's rmem.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>

---

Changes since v1:
 - Update schema to new driver design

 .../devicetree/bindings/nvmem/rmem.yaml       | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/rmem.yaml

diff --git a/Documentation/devicetree/bindings/nvmem/rmem.yaml b/Documentation/devicetree/bindings/nvmem/rmem.yaml
new file mode 100644
index 000000000000..29b53871aa02
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/rmem.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/rmem.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Reserved Memory Based nvmem Device
+
+maintainers:
+  - Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    items:
+      - enum:
+        - raspberrypi,bootloader-config
+      - const: nvmem-rmem
+
+  no-map:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Avoid creating a virtual mapping of the region as part of the OS'
+      standard mapping of system memory.
+
+required:
+  - compatible
+  - no-map
+
+unevaluatedProperties: false
+
+examples:
+  - |
+        reserved-memory {
+                #address-cells = <1>;
+                #size-cells = <1>;
+
+                blconfig: nvram at 10000000 {
+                        compatible = "raspberrypi,bootloader-config", "nvmem-rmem";
+                        #address-cells = <1>;
+                        #size-cells = <1>;
+                        reg = <0x10000000 0x1000>;
+                        no-map;
+                };
+        };
+
+...
-- 
2.29.2




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