From:   Atish Patra <atishp@atishpatra.org>
To:     linux-kernel@vger.kernel.org
Cc:     Atish Patra <atishp@rivosinc.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Atish Patra <atishp@atishpatra.org>,
        Anup Patel <anup@brainfault.org>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        devicetree@vger.kernel.org, Jisheng Zhang <jszhang@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        linux-riscv@lists.infradead.org,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Rob Herring <robh+dt@kernel.org>
Subject: [PATCH v1 2/2] dt-bindings: riscv: Add DT binding for RISC-V ISA extensions
Date:   Fri, 24 Dec 2021 13:16:32 -0800
Message-Id: <20211224211632.1698523-3-atishp@rivosinc.com>
In-Reply-To: <20211224211632.1698523-1-atishp@rivosinc.com>
References: <20211224211632.1698523-1-atishp@rivosinc.com>
MIME-Version: 1.0
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RISC-V ISA extensions can be single letter or multi-letter names.
The single letter extensions are mostly base extensions and encoded in
"riscv,isa" DT property. However, parsing the multi-letter extensions
via the isa string is cumbersome and is not scalable.

Add a new DT node for multi-letter extensions.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 Documentation/devicetree/bindings/riscv/cpus.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
index aa5fb64d57eb..6c4eecf389a9 100644
--- a/Documentation/devicetree/bindings/riscv/cpus.yaml
+++ b/Documentation/devicetree/bindings/riscv/cpus.yaml
@@ -78,6 +78,15 @@ properties:
       - rv64imac
       - rv64imafdc
 
+  riscv,isa-ext:
+    description:
+      Identifies the specific RISC-V instruction set architecture extensions
+      supported by one or multiple harts. All the multi-letter extensions
+      should be listed here as a boolean property. This subnode can be under
+      /cpus or under individual cpu node. In case of former, it represent
+      the common ISA extensions for all harts. The name of the boolean property
+      must match the actual ISA extension name in all lowercase format.
+    $ref: "/schemas/types.yaml#/definitions/boolean"
   # RISC-V requires 'timebase-frequency' in /cpus, so disallow it here
   timebase-frequency: false
 
-- 
2.33.1