[PATCH V4 2/3] dt-bindings: update riscv plic compatible string

guoren at kernel.org guoren at kernel.org
Fri Oct 15 20:21:59 PDT 2021

From: Guo Ren <guoren at linux.alibaba.com>

Add the compatible string "thead,c900-plic" to the riscv plic
bindings to support allwinner d1 SOC which contains c906 core.

Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Cc: Rob Herring <robh at kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt at google.com>
Cc: Anup Patel <anup at brainfault.org>
Cc: Atish Patra <atish.patra at wdc.com>


Changes since V4:
 - Update description in errata style
 - Update enum suggested by Anup, Heiko, Samuel

Changes since V3:
 - Rename "c9xx" to "c900"
 - Add thead,c900-plic in the description section
 .../interrupt-controller/sifive,plic-1.0.0.yaml       | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/sifive,plic-1.0.0.yaml b/Documentation/devicetree/bindings/interrupt-controller/sifive,plic-1.0.0.yaml
index 08d5a57ce00f..272f29540135 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/sifive,plic-1.0.0.yaml
+++ b/Documentation/devicetree/bindings/interrupt-controller/sifive,plic-1.0.0.yaml
@@ -35,6 +35,12 @@ description:
   contains a specific memory layout, which is documented in chapter 8 of the
   SiFive U5 Coreplex Series Manual <https://static.dev.sifive.com/U54-MC-RVCoreIP.pdf>.
+  The C9xx PLIC does not comply with the interrupt claim/completion process defined
+  by the RISC-V PLIC specification because C9xx PLIC will mask an IRQ when it is
+  claimed by PLIC driver (i.e. readl(claim) and the IRQ will be unmasked upon
+  completion by PLIC driver (i.e. writel(claim). This behaviour breaks the handling
+  of IRQS_ONESHOT by the generic handle_fasteoi_irq() used in the PLIC driver.
   - Sagar Kadam <sagar.kadam at sifive.com>
   - Paul Walmsley  <paul.walmsley at sifive.com>
@@ -46,7 +52,10 @@ properties:
       - enum:
           - sifive,fu540-c000-plic
           - canaan,k210-plic
-      - const: sifive,plic-1.0.0
+      - enmu:
+          - sifive,plic-1.0.0
+          - thead,c900-plic
+          - allwinner,sun20i-d1-plic
     maxItems: 1

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