[PATCH v6 1/2] dt-bindings: rng: add bindings for sec-rng

[Neal Liu <neal.liu@mediatek.com>]

Add bindings for ARM TrustZone based Security Random
Number Generator.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
---
 Documentation/devicetree/bindings/rng/sec-rng.yaml |   53 ++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/sec-rng.yaml

diff --git a/Documentation/devicetree/bindings/rng/sec-rng.yaml b/Documentation/devicetree/bindings/rng/sec-rng.yaml
new file mode 100644
index 0000000..7f4ae50
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/sec-rng.yaml
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# # Copyright 2020 MediaTek Inc.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/rng/sec-rng.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Security Random Number Generator
+
+description: |
+  sec-rng is a security random number generator which provides a generic
+  interface to get hardware rnd from Secure state. The Secure state can be
+  Arm Trusted Firmware(ATF), Trusted Execution Environment(TEE), or even
+  EL2 hypervisor.
+
+maintainer:
+  - Neal Liu <neal.liu@mediatek.com>
+
+properties:
+  compatible:
+    enum:
+      - arm,sec-rng
+
+  method:
+    description: The method of calling to Secure state
+    enum:
+      - smc
+      - hvc
+
+  method-fid:
+    description: The function number within the SMC and HVC function identifier
+    maxItems: 1
+
+  quality:
+    description: Estimation of true entropy in RNG's bitstream per 1024 bits
+    maxItems: 1
+
+required:
+  - compatible
+  - methods
+  - method-fid
+  - quality
+
+additionalProperties: false
+
+examples:
+  - |
+    hwrng: hwrng {
+            compatible = "arm,sec-rng";
+            method = "smc";
+            method-fid = /bits/ 16 <0x26a>;
+            quality = /bits/ 16 <900>;
+    };
-- 
1.7.9.5