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| 1 | +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause |
| 2 | +%YAML 1.2 |
| 3 | +--- |
| 4 | +$id: http://devicetree.org/schemas/interrupt-controller/riscv,cpu-intc.yaml# |
| 5 | +$schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | + |
| 7 | +title: RISC-V Hart-Level Interrupt Controller (HLIC) |
| 8 | + |
| 9 | +description: |
| 10 | + RISC-V cores include Control Status Registers (CSRs) which are local to |
| 11 | + each CPU core (HART in RISC-V terminology) and can be read or written by |
| 12 | + software. Some of these CSRs are used to control local interrupts connected |
| 13 | + to the core. Every interrupt is ultimately routed through a hart's HLIC |
| 14 | + before it interrupts that hart. |
| 15 | + |
| 16 | + The RISC-V supervisor ISA manual specifies three interrupt sources that are |
| 17 | + attached to every HLIC namely software interrupts, the timer interrupt, and |
| 18 | + external interrupts. Software interrupts are used to send IPIs between |
| 19 | + cores. The timer interrupt comes from an architecturally mandated real- |
| 20 | + time timer that is controlled via Supervisor Binary Interface (SBI) calls |
| 21 | + and CSR reads. External interrupts connect all other device interrupts to |
| 22 | + the HLIC, which are routed via the platform-level interrupt controller |
| 23 | + (PLIC). |
| 24 | + |
| 25 | + All RISC-V systems that conform to the supervisor ISA specification are |
| 26 | + required to have a HLIC with these three interrupt sources present. Since |
| 27 | + the interrupt map is defined by the ISA it's not listed in the HLIC's device |
| 28 | + tree entry, though external interrupt controllers (like the PLIC, for |
| 29 | + example) will need to define how their interrupts map to the relevant HLICs. |
| 30 | + This means a PLIC interrupt property will typically list the HLICs for all |
| 31 | + present HARTs in the system. |
| 32 | + |
| 33 | +maintainers: |
| 34 | + - Palmer Dabbelt <[email protected]> |
| 35 | + - Paul Walmsley <[email protected]> |
| 36 | + |
| 37 | +properties: |
| 38 | + compatible: |
| 39 | + oneOf: |
| 40 | + - items: |
| 41 | + - const: andestech,cpu-intc |
| 42 | + - const: riscv,cpu-intc |
| 43 | + - const: riscv,cpu-intc |
| 44 | + |
| 45 | + interrupt-controller: true |
| 46 | + |
| 47 | + '#interrupt-cells': |
| 48 | + const: 1 |
| 49 | + description: | |
| 50 | + The interrupt sources are defined by the RISC-V supervisor ISA manual, |
| 51 | + with only the following three interrupts being defined for |
| 52 | + supervisor mode: |
| 53 | + - Source 1 is the supervisor software interrupt, which can be sent by |
| 54 | + an SBI call and is reserved for use by software. |
| 55 | + - Source 5 is the supervisor timer interrupt, which can be configured |
| 56 | + by SBI calls and implements a one-shot timer. |
| 57 | + - Source 9 is the supervisor external interrupt, which chains to all |
| 58 | + other device interrupts. |
| 59 | +
|
| 60 | +required: |
| 61 | + - compatible |
| 62 | + - '#interrupt-cells' |
| 63 | + - interrupt-controller |
| 64 | + |
| 65 | +additionalProperties: false |
| 66 | + |
| 67 | +examples: |
| 68 | + - | |
| 69 | + interrupt-controller { |
| 70 | + #interrupt-cells = <1>; |
| 71 | + compatible = "riscv,cpu-intc"; |
| 72 | + interrupt-controller; |
| 73 | + }; |
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