On Fri, May 17, 2024 at 9:34 PM Conor Dooley <conor@xxxxxxxxxx> wrote:
>
> Yo,
>
> On Fri, May 17, 2024 at 08:37:40PM +0530, Kanak Shilledar wrote:
> > Convert the RISC-V Hart-Level Interrupt Controller (HLIC) to newer
> > DT schema, Created DT schema based on the .txt file which had
> > `compatible`, `#interrupt-cells` and `interrupt-controller` as
> > required properties.
> > Changes made with respect to original file:
> > - Changed the example to just use interrupt-controller instead of
> > using the whole cpu block
> > - Changed the example compatible string.
> >
> > Signed-off-by: Kanak Shilledar <kanakshilledar111@xxxxxxxxxxxxxx>
> > ---
> > .../interrupt-controller/riscv,cpu-intc.txt | 52 -----------------
> > .../interrupt-controller/riscv,cpu-intc.yaml | 57 +++++++++++++++++++
> > 2 files changed, 57 insertions(+), 52 deletions(-)
> > delete mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> > deleted file mode 100644
> > index 265b223cd978..000000000000
> > --- a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt
> > +++ /dev/null
> > @@ -1,52 +0,0 @@
> > -RISC-V Hart-Level Interrupt Controller (HLIC)
> > ----------------------------------------------
> > -
> > -RISC-V cores include Control Status Registers (CSRs) which are local to each
> > -CPU core (HART in RISC-V terminology) and can be read or written by software.
> > -Some of these CSRs are used to control local interrupts connected to the core.
> > -Every interrupt is ultimately routed through a hart's HLIC before it
> > -interrupts that hart.
> > -
> > -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
> > -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).
> > -
> > -All RISC-V systems that conform to the supervisor ISA specification are
> > -required to have a HLIC with these three interrupt sources present. Since the
> > -interrupt map is defined by the ISA it's not listed in the HLIC's device tree
> > -entry, though external interrupt controllers (like the PLIC, for example) will
> > -need to define how their interrupts map to the relevant HLICs. This means
> > -a PLIC interrupt property will typically list the HLICs for all present HARTs
> > -in the system.
> > -
> > -Required properties:
> > -- compatible : "riscv,cpu-intc"
>
> > -- #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.
>
> I don't think that we should remove this test from the binding.
Do you suggest adding it as a description for the `#interrupt-cells` property?
> > -- 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.
> > -
> > -An example device tree entry for a HLIC is show below.
> > -
> > - cpu1: cpu@1 {
> > - compatible = "riscv";
> > - ...
> > - cpu1-intc: interrupt-controller {
> > - #interrupt-cells = <1>;
> > - compatible = "sifive,fu540-c000-cpu-intc", "riscv,cpu-intc";
> > - interrupt-controller;
> > - };
> > - };
> > diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.yaml
> > new file mode 100644
> > index 000000000000..6fe86d243633
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.yaml
> > @@ -0,0 +1,57 @@
> > +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/interrupt-controller/riscv,cpu-intc.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RISC-V Hart-Level Interrupt Controller (HLIC)
> > +
> > +description:
> > + RISC-V cores include Control Status Registers (CSRs) which are local to
> > + each CPU core (HART in RISC-V terminology) and can be read or written by
> > + software. Some of these CSRs are used to control local interrupts connected
> > + to the core. Every interrupt is ultimately routed through a hart's HLIC
> > + before it interrupts that hart.
> > +
> > + The RISC-V supervisor ISA manual specifies three interrupt sources that are
> > + attached to every HLIC namely 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 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).
> > +
> > + All RISC-V systems that conform to the supervisor ISA specification are
> > + required to have a HLIC with these three interrupt sources present. Since
> > + the interrupt map is defined by the ISA it's not listed in the HLIC's device
> > + tree entry, though external interrupt controllers (like the PLIC, for
> > + example) will need to define how their interrupts map to the relevant HLICs.
> > + This means a PLIC interrupt property will typically list the HLICs for all
> > + present HARTs in the system.
> > +
>
> > +maintainers:
> > + - Kanak Shilledar <kanakshilledar111@xxxxxxxxxxxxxx>
>
> Are you knowledgeable about the cpu-intc on RISC-V? If you put yourself
> down just to satisfy dt_binding_check, I would suggest that you put down
> Palmer and Paul here as the maintainers of the architecture instead.
I am adding Palmer and Paul as maintainers in the v2 patch.
> > +properties:
> > + compatible:
> > + const: "riscv,cpu-intc"
>
> A new warning with dtbs_check from your patch:
> /stuff/linux/build/arch/riscv/boot/dts/renesas/r9a07g043f01-smarc.dtb: interrupt-controller: compatible:0: 'riscv,cpu-intc' was expected
> from schema $id: http://devicetree.org/schemas/interrupt-controller/riscv,cpu-intc.yaml#
> /stuff/linux/build/arch/riscv/boot/dts/renesas/r9a07g043f01-smarc.dtb: interrupt-controller: compatible: ['andestech,cpu-intc', 'riscv,cpu-intc'] is too long
> from schema $id: http://devicetree.org/schemas/interrupt-controller/riscv,cpu-intc.yaml#
>
> There's a duplicate description in riscv/cpus.yaml:
> interrupt-controller:
> type: object
> additionalProperties: false
> description: Describes the CPU's local interrupt controller
>
> properties:
> '#interrupt-cells':
> const: 1
>
> compatible:
> oneOf:
> - items:
> - const: andestech,cpu-intc
> - const: riscv,cpu-intc
> - const: riscv,cpu-intc
>
> interrupt-controller: true
>
> I think the one in cpus.yaml should be converted to a ref and the
> andestech compatible added here.
I am working on the v2 patch, in which I didn't provide any ref to the
cpus.yaml and just replaced my compatible section with the one above
to resolve the issue with `/renesas/r9a07g043f01-smarc.dtb`. I tested
with others and didn't get any warnings.
> > + interrupt-controller: true
> > +
> > + '#interrupt-cells': true
>
> `const: 1` to match the text binding being removed.
>
> Cheers,
> Conor.
>
> > +
> > +required:
> > + - compatible
> > + - '#interrupt-cells'
> > + - interrupt-controller
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + interrupt-controller {
> > + #interrupt-cells = <1>;
> > + compatible = "riscv,cpu-intc";
> > + interrupt-controller;
> > + };
> > --
> > 2.34.1
> >
Thanks and Regards,
Kanak Shilledar
