Re: [PATCH 5/5] dt-bindings: timer: Add CLINT bindings

From: Palmer Dabbelt
Date: Thu Jun 04 2020 - 16:40:34 EST


On Thu, 21 May 2020 06:45:44 PDT (-0700), Anup Patel wrote:
We add DT bindings documentation for CLINT device.

Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
---
.../bindings/timer/sifive,clint.txt | 33 +++++++++++++++++++
1 file changed, 33 insertions(+)
create mode 100644 Documentation/devicetree/bindings/timer/sifive,clint.txt

diff --git a/Documentation/devicetree/bindings/timer/sifive,clint.txt b/Documentation/devicetree/bindings/timer/sifive,clint.txt
new file mode 100644
index 000000000000..cae2dad1223a
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/sifive,clint.txt
@@ -0,0 +1,33 @@
+SiFive Core Local Interruptor (CLINT)
+-------------------------------------
+
+SiFive (and other RISC-V) SOCs include an implementation of the SiFive Core
+Local Interruptor (CLINT) for M-mode timer and inter-processor interrupts.
+
+It directly connects to the timer and inter-processor interrupt lines of
+various HARTs (or CPUs) so RISC-V per-HART (or per-CPU) local interrupt
+controller is the parent interrupt controller for CLINT device.
+
+The clock frequency of CLINT is specified via "timebase-frequency" DT
+property of "/cpus" DT node. The "timebase-frequency" DT property is
+described in: Documentation/devicetree/bindings/riscv/cpus.yaml
+
+Required properties:
+- compatible : "sifive,clint-1.0.0" and a string identifying the actual
+ detailed implementation in case that specific bugs need to be worked around.
+- reg : Should contain 1 register range (address and length).
+- interrupts-extended : Specifies which HARTs (or CPUs) are connected to
+ the CLINT. Each node pointed to should be a riscv,cpu-intc node, which
+ has a riscv node as parent.
+
+Example:
+
+ clint@2000000 {
+ compatible = "sifive,clint-1.0.0", "sifive,fu540-c000-clint";
+ interrupts-extended = <
+ &cpu1-intc 3 &cpu1-intc 7
+ &cpu2-intc 3 &cpu2-intc 7
+ &cpu3-intc 3 &cpu3-intc 7
+ &cpu4-intc 3 &cpu4-intc 7>;
+ reg = <0x2000000 0x4000000>;
+ };

Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>