From: "Wesley W. Terpstra" <wes...@sifive.com>
Signed-off-by: Palmer Dabbelt <pal...@dabbelt.com>
---
.../interrupt-controller/riscv,cpu-intc.txt | 46 ++++++++++++++++++++++
.../bindings/interrupt-controller/riscv,plic0.txt | 44 +++++++++++++++++++++
2 files changed, 90 insertions(+)
create mode 100644
Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
create mode 100644
Documentation/devicetree/bindings/interrupt-controller/riscv,plic0.txt
diff --git
a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
new file mode 100644
index 000000000000..62f02e834ff9
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
@@ -0,0 +1,46 @@
+RISC-V Hart-Level Interrupt Controller (HLIC)
+---------------------------------------------
+
+RISC-V cores include Control Status Registers (CSRs) which are local to each
+hart and can be read or written by software. Some of these CSRs are used to
+control local interrupts connected to the core.
+
+Typical examples of local interrupts on a RISC-V core include: software IPI
+interrupts, timer interrupts, and a link to the PLIC interrupt controller.
+
+Required properties:
+- compatible : "riscv,cpu-intc"
+- #interrupt-cells : should be <1>
+- interrupt-controller : Identifies the node as an interrupt controller
+
+Furthermore, this interrupt-controller MUST be embedded inside the cpu
+definition of the hart whose CSRs control these local interrupts.
+
+Example:
+
+ cpu1: cpu@1 {
+ clock-frequency = <1600000000>;
+ compatible = "riscv";
+ d-cache-block-size = <64>;
+ d-cache-sets = <64>;
+ d-cache-size = <16384>;
+ d-tlb-sets = <1>;
+ d-tlb-size = <32>;
+ device_type = "cpu";
+ i-cache-block-size = <64>;
+ i-cache-sets = <64>;
+ i-cache-size = <16384>;
+ i-tlb-sets = <1>;
+ i-tlb-size = <32>;
+ mmu-type = "riscv,sv39";
+ next-level-cache = <&L2>;
+ reg = <1>;
+ riscv,isa = "rv64imac";
+ status = "okay";
+ tlb-split;
+ cpu1-intc: interrupt-controller {
+ #interrupt-cells = <1>;
+ compatible = "riscv,cpu-intc";
+ interrupt-controller;
+ };
+ };
diff --git
a/Documentation/devicetree/bindings/interrupt-controller/riscv,plic0.txt
b/Documentation/devicetree/bindings/interrupt-controller/riscv,plic0.txt
new file mode 100644
index 000000000000..c05b5806f7d2
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,plic0.txt
@@ -0,0 +1,44 @@
+RISC-V Platform-Level Interrupt Controller (PLIC)
+-------------------------------------------------
+
+RISC-V cores typically include a PLIC, which route interrupts from multiple
+devices to multiple hart contexts. The PLIC is connected to the interrupt
+controller embedded in a RISC-V core via the interrupt-related CSRs.
+
+A hart context is a priviledge mode in a hardware execution thread. For
+example, in an 4 core system with 2-way SMT, you have 8 harts and probably
+at least two priviledge modes per hart; machine mode and supervisor mode.
+
+Each interrupt can be enabled on per-context basis. Any context can claim
+a pending enabled interrupt and then release it once it has been handled.
+
+Each interrupt has a configurable priority. Higher priority interrupts are
+serviced firs. Each context can specify a priority threshold. Interrupts
+with priority below this threshold will not cause the PLIC to raise its
+interrupt line leading to the context.
+
+Required properties:
+- compatible : "riscv,plic0"
+- #address-cells : should be <0>
+- #interrupt-cells : should be <1>
+- interrupt-controller : Identifies the node as an interrupt controller
+- reg : Should contain 1 register range (address and length)
+- riscv,ndev : Specifies the number of interrupts attached to the PLIC
+- interrupts-extended : Specifies which contexts are connected to the PLIC
+
+Example:
+
+ plic: interrupt-controller@c000000 {
+ #address-cells = <0>;
+ #interrupt-cells = <1>;
+ compatible = "riscv,plic0";
+ interrupt-controller;
+ interrupts-extended = <
+ &cpu0-intc 11
+ &cpu1-intc 11 &cpu1-intc 9
+ &cpu2-intc 11 &cpu2-intc 9
+ &cpu3-intc 11 &cpu3-intc 9
+ &cpu4-intc 11 &cpu4-intc 9>;
+ reg = <0xc000000 0x4000000>;
+ riscv,ndev = <10>;
+ };
--
2.13.0
