path: root/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
diff options
Diffstat (limited to 'Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt')
1 files changed, 11 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
index b0a8af51c388..265b223cd978 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
@@ -11,7 +11,7 @@ The RISC-V supervisor ISA manual specifies three interrupt sources that are
attached to every HLIC: software interrupts, the timer interrupt, and external
interrupts. Software interrupts are used to send IPIs between cores. The
timer interrupt comes from an architecturally mandated real-time timer that is
-controller via Supervisor Binary Interface (SBI) calls and CSR reads. External
+controlled via Supervisor Binary Interface (SBI) calls and CSR reads. External
interrupts connect all other device interrupts to the HLIC, which are routed
via the platform-level interrupt controller (PLIC).
@@ -25,7 +25,15 @@ in the system.
Required properties:
- compatible : "riscv,cpu-intc"
-- #interrupt-cells : should be <1>
+- #interrupt-cells : should be <1>. The interrupt sources are defined by the
+ RISC-V supervisor ISA manual, with only the following three interrupts being
+ defined for supervisor mode:
+ - Source 1 is the supervisor software interrupt, which can be sent by an SBI
+ call and is reserved for use by software.
+ - Source 5 is the supervisor timer interrupt, which can be configured by
+ SBI calls and implements a one-shot timer.
+ - Source 9 is the supervisor external interrupt, which chains to all other
+ device interrupts.
- interrupt-controller : Identifies the node as an interrupt controller
Furthermore, this interrupt-controller MUST be embedded inside the cpu
@@ -38,7 +46,7 @@ An example device tree entry for a HLIC is show below.
cpu1-intc: interrupt-controller {
#interrupt-cells = <1>;
- compatible = "riscv,cpu-intc", "sifive,fu540-c000-cpu-intc";
+ compatible = "sifive,fu540-c000-cpu-intc", "riscv,cpu-intc";