[PATCH v3 2/4] dt-bindings: reserved-memory: Support MTD/block device

[Vincent Whitchurch <vincent.whitchurch@axis.com>]

Add bindings to allow MTD/block devices to be used in reserved-memory
regions using the "phram" (MTD in PHysical RAM) driver.

This allows things like partitioning to be specified via the existing
devicetree bindings.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---

Notes:
    v3:
    - Reword description.
    
    v2:
    - Add note on what "phram" means.
    - Use /schemas/mtd/mtd.yaml instead of relative pathUse /schemas/mtd/mtd.yaml instead of relative path.

 .../bindings/reserved-memory/phram.yaml       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/phram.yaml

diff --git a/Documentation/devicetree/bindings/reserved-memory/phram.yaml b/Documentation/devicetree/bindings/reserved-memory/phram.yaml
new file mode 100644
index 000000000000..6c4db28015f1
--- /dev/null
+++ b/Documentation/devicetree/bindings/reserved-memory/phram.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/phram.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MTD/block device in RAM
+
+description: |
+  Specifies that the reserved memory region can be used as an MTD or block
+  device.
+
+  The "phram" node is named after the "MTD in PHysical RAM" driver which
+  provides an implementation of this functionality in Linux.
+
+maintainers:
+  - Vincent Whitchurch <vincent.whitchurch@axis.com>
+
+allOf:
+  - $ref: "reserved-memory.yaml"
+  - $ref: "/schemas/mtd/mtd.yaml"
+
+properties:
+  compatible:
+    const: phram
+
+  reg:
+    description: region of memory that can be used as an MTD/block device
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    reserved-memory {
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        phram: flash@12340000 {
+            compatible = "phram";
+            label = "rootfs";
+            reg = <0x12340000 0x00800000>;
+        };
+    };
-- 
2.34.1