[PATCH v8 1/3] dt-bindings: rng: Add Rockchip RK3568 TRNG

[Daniel Golle]

From: Aurelien Jarno <aurelien at aurel32.net>

Add the True Random Number Generator on the Rockchip RK3568 SoC.

Signed-off-by: Aurelien Jarno <aurelien at aurel32.net>
Signed-off-by: Daniel Golle <daniel at makrotopia.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
 .../bindings/rng/rockchip,rk3568-rng.yaml     | 82 +++++++++++++++++++
 MAINTAINERS                                   |  6 ++
 2 files changed, 88 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml

diff --git a/Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml b/Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml
new file mode 100644
index 000000000000..383a39e60ad8
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/rockchip,rk3568-rng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Rockchip RK3568 TRNG
+
+description: True Random Number Generator on Rockchip RK3568 SoC
+
+maintainers:
+  - Aurelien Jarno <aurelien at aurel32.net>
+  - Daniel Golle <daniel at makrotopia.org>
+
+properties:
+  compatible:
+    enum:
+      - rockchip,rk3568-rng
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: TRNG clock
+      - description: TRNG AHB clock
+
+  clock-names:
+    items:
+      - const: core
+      - const: ahb
+
+  quality:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0
+    description:
+      Estimated number of bits of true entropy per 1024 bits read from the rng.
+      Defaults to zero which causes the kernel's default quality to be used
+      instead.  Note that the default quality is usually zero which disables
+      using this rng to automatically fill the kernel's entropy pool.
+
+  rockchip,sample-count:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 1000
+    description:
+      Bits to skip on TRNG osc ring output before collection.
+      The value is a tradeoff between speed and quality, the higher the slower
+      and the better quality.
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - quality
+  - resets
+  - rockchip,sample-count
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/rk3568-cru.h>
+    bus {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      rng at fe388000 {
+        compatible = "rockchip,rk3568-rng";
+        reg = <0x0 0xfe388000 0x0 0x4000>;
+        clocks = <&cru CLK_TRNG_NS>, <&cru HCLK_TRNG_NS>;
+        clock-names = "core", "ahb";
+        quality = <900>;
+        resets = <&cru SRST_TRNG_NS>;
+        rockchip,sample-count = <1000>;
+      };
+    };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 61053a8c625e..41aecf9736c9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19707,6 +19707,12 @@ F:	Documentation/userspace-api/media/v4l/metafmt-rkisp1.rst
 F:	drivers/media/platform/rockchip/rkisp1
 F:	include/uapi/linux/rkisp1-config.h
 
+ROCKCHIP RK3568 RANDOM NUMBER GENERATOR SUPPORT
+M:	Daniel Golle <daniel at makrotopia.org>
+M:	Aurelien Jarno <aurelien at aurel32.net>
+S:	Maintained
+F:	Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml
+
 ROCKCHIP RASTER 2D GRAPHIC ACCELERATION UNIT DRIVER
 M:	Jacob Chen <jacob-chen at iotwrt.com>
 M:	Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>
-- 
2.45.2