[PATCH v5 4/4] dt-bindings: timer: Add CLINT bindings

[Anup Patel]

On Thu, Jul 23, 2020 at 10:38 PM Rob Herring <robh at kernel.org> wrote:
>
> On Thu, Jul 23, 2020 at 07:54:09PM +0530, Anup Patel wrote:
> > We add DT bindings documentation for CLINT device.
> >
> > Signed-off-by: Anup Patel <anup.patel at wdc.com>
> > Reviewed-by: Palmer Dabbelt <palmerdabbelt at google.com>
> > Tested-by: Emil Renner Berhing <kernel at esmil.dk>
> > ---
> >  .../bindings/timer/sifive,clint.yaml          | 58 +++++++++++++++++++
> >  1 file changed, 58 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/timer/sifive,clint.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/timer/sifive,clint.yaml b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
> > new file mode 100644
> > index 000000000000..8ad115611860
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/timer/sifive,clint.yaml
> > @@ -0,0 +1,58 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/timer/sifive,clint.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: SiFive Core Local Interruptor
> > +
> > +maintainers:
> > +  - Palmer Dabbelt <palmer at dabbelt.com>
> > +  - Anup Patel <anup.patel at wdc.com>
> > +
> > +description:
> > +  SiFive (and other RISC-V) SOCs include an implementation of the SiFive
> > +  Core Local Interruptor (CLINT) for M-mode timer and M-mode 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
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - const: sifive,clint0
> > +      - const: sifive,fu540-c000-clint
>
> Wrong order. Most specific goes first.

Okay, will update.

>
> > +
> > +    description:
> > +      Should be "sifive,<chip>-clint" and "sifive,clint<version>".
> > +      Supported compatible strings are -
> > +      "sifive,fu540-c000-clint" for the SiFive CLINT v0 as integrated
> > +      onto the SiFive FU540 chip, and "sifive,clint0" for the SiFive
> > +      CLINT v0 IP block with no chip integration tweaks.
> > +      Please refer to sifive-blocks-ip-versioning.txt for details
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts-extended:
> > +    minItems: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts-extended
>
> Add:
>
> additionalProperties: false

Okay, will add.

>
> > +
> > +examples:
> > +  - |
> > +    clint at 2000000 {
>
> timer at ...

Okay, will rename.

>
> > +      compatible = "sifive,clint0", "sifive,fu540-c000-clint";
> > +      interrupts-extended = <&cpu1intc 3 &cpu1intc 7
> > +                             &cpu2intc 3 &cpu2intc 7
> > +                             &cpu3intc 3 &cpu3intc 7
> > +                             &cpu4intc 3 &cpu4intc 7>;
> > +       reg = <0x2000000 0x4000000>;
>
> 64MB of register space? Doesn't matter much for 64-bit, but would waste
> lots of virtual space (low mem) on 32-bit.

This is a typo. The register space size is 64KB not 64MB. I will update.

>
> > +    };
> > +...
> > --
> > 2.25.1
> >

Regards,
Anup