[PATCH v2 07/13] dt-bindings: riscv: Add B ISA extension description

[Guodong Xu]

Add description of the single-letter "B" extennsion for Bit Manipulation.
B is mandatory for RVA23U64.

The B extension is ratified in the 20240411 version of the unprivileged
ISA specification. According to the ratified spec, "the B standard
extension comprises instructions provided by the Zba, Zbb, and Zbs
extensions.

Hence add a schema check rule to enforce that B implies Zba, Zbb and Zbs.

Signed-off-by: Guodong Xu <guodong at riscstar.com>
---
v2: New patch.
---
 .../devicetree/bindings/riscv/extensions.yaml         | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index 565cb2cbb49b552959392810a9b731b43346a594..385e1deb23996d294e7662693f1257f910a6e129 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -109,6 +109,13 @@ properties:
             The standard C extension for compressed instructions, as ratified in
             the 20191213 version of the unprivileged ISA specification.
 
+        - const: b
+          description:
+            The standard B extension for bit manipulation instructions, as
+            ratified in the 20240411 version of the unprivileged ISA
+            specification. The B standard extension comprises instructions
+            provided by the Zba, Zbb, and Zbs extensions.
+
         - const: v
           description:
             The standard V extension for vector operations, as ratified
@@ -735,6 +742,18 @@ properties:
         then:
           contains:
             const: f
+      # b comprises the following extensions
+      - if:
+          contains:
+            const: b
+        then:
+          allOf:
+            - contains:
+                const: zba
+            - contains:
+                const: zbb
+            - contains:
+                const: zbs
       # Zcb depends on Zca
       - if:
           contains:

-- 
2.43.0