[PATCH v6] dt-bindings: arm: samsung: Update the CHIPID binding for ASV

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

This patch adds documentation of new optional "samsung,asv-bin"
property in the chipid device node and documents requirement of
"syscon" compatible string.  These additions are needed to support
Exynos ASV (Adaptive Supply Voltage) feature.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
Depends on patch ("8d0daa4c89c9 dt-bindings: arm: samsung: Convert
Exynos Chipid bindings to json-schema") already applied to Rob's
dt/next.

Changes since v5:
 - removed uneeded allOf from 'compatible' property section

Changes since v4:
 - converted to YAML

Changes since v3:
 - none

Changes since v2:
 - corrected patch summary line prefix, the patch moved in the
   sequence

Changes since v1 (RFC):
 - new patch
---
 .../bindings/arm/samsung/exynos-chipid.yaml   | 26 ++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-chipid.yaml b/Documentation/devicetree/bindings/arm/samsung/exynos-chipid.yaml
index 9c573ad7dc7d..c7f06aa1963c 100644
--- a/Documentation/devicetree/bindings/arm/samsung/exynos-chipid.yaml
+++ b/Documentation/devicetree/bindings/arm/samsung/exynos-chipid.yaml
@@ -9,17 +9,41 @@ title: Samsung Exynos SoC series Chipid driver
 maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>

+# Custom select to avoid matching all nodes with 'syscon'
+select:
+  properties:
+    compatible:
+      contains:
+        const: samsung,exynos4210-chipid
+  required:
+    - compatible
+
 properties:
   compatible:
     items:
       - const: samsung,exynos4210-chipid
+      - const: syscon

   reg:
     maxItems: 1

+  samsung,asv-bin:
+    description:
+      Adaptive Supply Voltage bin selection. This can be used
+      to determine the ASV bin of an SoC if respective information
+      is missing in the CHIPID registers or in the OTP memory.
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+      - enum: [ 0, 1, 2, 3 ]
+
+required:
+  - compatible
+  - reg
+
 examples:
   - |
     chipid@10000000 {
-      compatible = "samsung,exynos4210-chipid";
+      compatible = "samsung,exynos4210-chipid", "syscon";
       reg = <0x10000000 0x100>;
+      samsung,asv-bin = <2>;
     };
--
2.17.1