[PATCH 2/7] dt-bindings: rng: Add Exynos850 support to exynos-trng

[Sam Protsenko]

The TRNG block in Exynos850 is pretty much the same as in Exynos5250,
but there are two clocks that has to be controlled to make it work:
  1. Functional (operating) clock: called ACLK in Exynos850, the same as
     "secss" clock in Exynos5250
  2. Interface (bus) clock: called PCLK in Exynos850. It has to be
     enabled in order to access TRNG registers

Document Exynos850 compatible and the related clock changes, and provide
a corresponding example for Exynos850 TRNG node with ACLK and PCLK
clocks.

Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
 .../bindings/rng/samsung,exynos-trng.yaml     | 49 +++++++++++++++++--
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/rng/samsung,exynos-trng.yaml b/Documentation/devicetree/bindings/rng/samsung,exynos-trng.yaml
index 99c382d25c11..e57310fa89c7 100644
--- a/Documentation/devicetree/bindings/rng/samsung,exynos-trng.yaml
+++ b/Documentation/devicetree/bindings/rng/samsung,exynos-trng.yaml
@@ -12,14 +12,17 @@ maintainers:
 
 properties:
   compatible:
-    const: samsung,exynos5250-trng
+    enum:
+      - samsung,exynos5250-trng
+      - samsung,exynos850-trng
 
   clocks:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
 
   clock-names:
-    items:
-      - const: secss
+    minItems: 1
+    maxItems: 2
 
   reg:
     maxItems: 1
@@ -30,6 +33,35 @@ required:
   - clock-names
   - reg
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: samsung,exynos850-trng
+
+    then:
+      properties:
+        clocks:
+          items:
+            - description: SSS (Security Sub System) operating clock
+            - description: SSS (Security Sub System) bus clock
+
+        clock-names:
+          items:
+            - const: secss
+            - const: pclk
+
+    else:
+      properties:
+        clocks:
+          items:
+            - description: SSS (Security Sub System) operating clock
+
+        clock-names:
+          items:
+            - const: secss
+
 additionalProperties: false
 
 examples:
@@ -42,3 +74,12 @@ examples:
         clocks = <&clock CLK_SSS>;
         clock-names = "secss";
     };
+  - |
+    #include <dt-bindings/clock/exynos850.h>
+
+    rng at 12081400 {
+        compatible = "samsung,exynos850-trng";
+        reg = <0x12081400 0x100>;
+        clocks = <&cmu_core CLK_GOUT_SSS_ACLK>, <&cmu_core CLK_GOUT_SSS_PCLK>;
+        clock-names = "secss", "pclk";
+    };
-- 
2.39.2