dt-bindings: reserved-memory: add linaro,secure-heap

DMABUF Reserved memory definition for OP-TEE SDP feaure.

Signed-off-by: Olivier Masse <[email protected]>

Author: omasse-nxp

Documentation/devicetree/bindings/reserved-memory/linaro,secure-heap.yaml

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/linaro,secure-heap.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Linaro Secure DMABUF Heap
+
+maintainers:
+  - Olivier Masse <[email protected]>
+
+description:
+  Linaro OP-TEE firmware needs a reserved memory for the
+  Secure Data Path feature (aka SDP).
+  The purpose is to provide a secure memory heap which allow
+  non-secure OS to allocate/free secure buffers.
+  The TEE is reponsible for protecting the SDP memory buffers.
+  TEE Trusted Application can access secure memory references
+  provided as parameters (DMABUF file descriptor).
+
+allOf:
+  - $ref: "reserved-memory.yaml"
+
+properties:
+  compatible:
+    const: linaro,secure-heap
+
+  reg:
+    description:
+      Region of memory reserved for OP-TEE SDP feature
+
+  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.
+
+unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - no-map
+
+examples:
+  - |
+  reserved-memory {
+    #address-cells = <2>;
+    #size-cells = <2>;
+
+    sdp@3e800000 {
+      compatible = "linaro,secure-heap";
+      no-map;
+      reg = <0 0x3E800000 0 0x00400000>;
+    };
+  };