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From:   Icenowy Zheng <uwu@icenowy.me>
To:     Marc Zyngier <maz@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Jisheng Zhang <jszhang@kernel.org>,
        Samuel Holland <samuel@sholland.org>
Cc:     linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-riscv@lists.infradead.org, Icenowy Zheng <uwu@icenowy.me>
Subject: [PATCH 1/3] dt-bindings: timer: sifive,clint: add comaptibles for T-Head's C9xx
Date:   Mon, 21 Nov 2022 12:17:55 +0800
Message-Id: <20221121041757.418645-2-uwu@icenowy.me>
In-Reply-To: <20221121041757.418645-1-uwu@icenowy.me>
References: <20221121041757.418645-1-uwu@icenowy.me>
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T-Head C906/C910 CLINT is not compliant to SiFive ones (and even not
compliant to the newcoming ACLINT spec) because of lack of mtime
register.

Add a compatible string formatted like the C9xx-specific PLIC
compatible, and do not allow a SiFive one as fallback because they're
not really compliant.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
---
 Documentation/devicetree/bindings/timer/sifive,clint.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/timer/sifive,clint.yaml b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
index bbad24165837..aada6957216c 100644
--- a/Documentation/devicetree/bindings/timer/sifive,clint.yaml
+++ b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
@@ -20,6 +20,10 @@ description:
   property of "/cpus" DT node. The "timebase-frequency" DT property is
   described in Documentation/devicetree/bindings/riscv/cpus.yaml
 
+  T-Head C906/C910 CPU cores include an implementation of CLINT too, however
+  their implementation lacks a memory-mapped MTIME register, thus not
+  compatible with SiFive ones.
+
 properties:
   compatible:
     oneOf:
@@ -29,6 +33,10 @@ properties:
               - starfive,jh7100-clint
               - canaan,k210-clint
           - const: sifive,clint0
+      - items:
+          - enum:
+              - allwinner,sun20i-d1-clint
+          - const: thead,c900-clint
       - items:
           - const: sifive,clint0
           - const: riscv,clint0
-- 
2.37.1