Re: [RESEND PATCH v2 1/1] dt-bindings: riscv: sifive-l2-cache: convert bindings to json-schema

[Rob Herring]

On Tue, Sep 15, 2020 at 9:17 AM Sagar Kadam <sagar.kadam@xxxxxxxxxxxx> wrote:
>
> Hello Rob,
>
> > -----Original Message-----
> > From: Rob Herring <robh@xxxxxxxxxx>
> > Sent: Monday, September 14, 2020 11:30 PM
> > To: Sagar Kadam <sagar.kadam@xxxxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-riscv@xxxxxxxxxxxxxxxxxxx;
> > devicetree@xxxxxxxxxxxxxxx; Paul Walmsley ( Sifive)
> > <paul.walmsley@xxxxxxxxxx>; palmer@xxxxxxxxxxx;
> > aou@xxxxxxxxxxxxxxxxx; Yash Shah <yash.shah@xxxxxxxxxxxx>
> > Subject: Re: [RESEND PATCH v2 1/1] dt-bindings: riscv: sifive-l2-cache:
> > convert bindings to json-schema
> >
> > [External Email] Do not click links or attachments unless you recognize the
> > sender and know the content is safe
> >
> > On Fri, Aug 28, 2020 at 10:25:43PM +0530, Sagar Kadam wrote:
> > > Convert the device tree bindings for the SiFive's FU540-C000 SoC's L2
> > Cache
> > > controller to YAML format.
> > >
> > > Signed-off-by: Sagar Kadam <sagar.kadam@xxxxxxxxxx>
> > > ---
> > >  .../devicetree/bindings/riscv/sifive-l2-cache.txt  | 51 ------------
> > >  .../devicetree/bindings/riscv/sifive-l2-cache.yaml | 92
> > ++++++++++++++++++++++
> > >  2 files changed, 92 insertions(+), 51 deletions(-)
> > >  delete mode 100644 Documentation/devicetree/bindings/riscv/sifive-l2-
> > cache.txt
> > >  create mode 100644 Documentation/devicetree/bindings/riscv/sifive-l2-
> > cache.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > b/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > > deleted file mode 100644
> > > index 73d8f19..0000000
> > > --- a/Documentation/devicetree/bindings/riscv/sifive-l2-cache.txt
> > > +++ /dev/null
> > > @@ -1,51 +0,0 @@
> > > -SiFive L2 Cache Controller
> > > ---------------------------
> > > -The SiFive Level 2 Cache Controller is used to provide access to fast
> > copies
> > > -of memory for masters in a Core Complex. The Level 2 Cache Controller
> > also
> > > -acts as directory-based coherency manager.
> > > -All the properties in ePAPR/DeviceTree specification applies for this
> > platform
> > > -
> > > -Required Properties:
> > > ---------------------
> > > -- compatible: Should be "sifive,fu540-c000-ccache" and "cache"
> > > -
> > > -- cache-block-size: Specifies the block size in bytes of the cache.
> > > -  Should be 64
> > > -
> > > -- cache-level: Should be set to 2 for a level 2 cache
> > > -
> > > -- cache-sets: Specifies the number of associativity sets of the cache.
> > > -  Should be 1024
> > > -
> > > -- cache-size: Specifies the size in bytes of the cache. Should be 2097152
> > > -
> > > -- cache-unified: Specifies the cache is a unified cache
> > > -
> > > -- interrupts: Must contain 3 entries (DirError, DataError and DataFail
> > signals)
> > > -
> > > -- reg: Physical base address and size of L2 cache controller registers map
> > > -
> > > -Optional Properties:
> > > ---------------------
> > > -- next-level-cache: phandle to the next level cache if present.
> > > -
> > > -- memory-region: reference to the reserved-memory for the L2 Loosely
> > Integrated
> > > -  Memory region. The reserved memory node should be defined as per
> > the bindings
> > > -  in reserved-memory.txt
> > > -
> > > -
> > > -Example:
> > > -
> > > -     cache-controller@2010000 {
> > > -             compatible = "sifive,fu540-c000-ccache", "cache";
> > > -             cache-block-size = <64>;
> > > -             cache-level = <2>;
> > > -             cache-sets = <1024>;
> > > -             cache-size = <2097152>;
> > > -             cache-unified;
> > > -             interrupt-parent = <&plic0>;
> > > -             interrupts = <1 2 3>;
> > > -             reg = <0x0 0x2010000 0x0 0x1000>;
> > > -             next-level-cache = <&L25 &L40 &L36>;
> > > -             memory-region = <&l2_lim>;
> > > -     };
> > > diff --git a/Documentation/devicetree/bindings/riscv/sifive-l2-cache.yaml
> > b/Documentation/devicetree/bindings/riscv/sifive-l2-cache.yaml
> > > new file mode 100644
> > > index 0000000..e14c8c6
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/riscv/sifive-l2-cache.yaml
> > > @@ -0,0 +1,92 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +# Copyright (C) 2020 SiFive, Inc.
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/riscv/sifive-l2-cache.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: SiFive L2 Cache Controller
> > > +
> > > +maintainers:
> > > +  - Sagar Kadam <sagar.kadam@xxxxxxxxxx>
> > > +  - Yash Shah <yash.shah@xxxxxxxxxx>
> > > +  - Paul Walmsley  <paul.walmsley@xxxxxxxxxx>
> > > +
> > > +description:
> > > +  The SiFive Level 2 Cache Controller is used to provide access to fast
> > copies
> > > +  of memory for masters in a Core Complex. The Level 2 Cache Controller
> > also
> > > +  acts as directory-based coherency manager.
> > > +  All the properties in ePAPR/DeviceTree specification applies for this
> > platform.
> > > +
> > > +allOf:
> > > +  - $ref: /schemas/cache-controller.yaml#
> > > +
> > > +properties:
> > > +  compatible:
> > > +    items:
> > > +     - enum:
> > > +        - sifive,fu540-c000-ccache
> > > +    description: |
> > > +      Should have "sifive,<soc>-cache" and "cache".
> >
> > That's not what the schema describes or the example has (the 'cache'
> > fallback).
> >
> Thanks for your suggestions.
> I see that if we include the standard 'cache' property here, it injects  error's in other yaml's as reported here [1]
> In plain txt format of this binding the standard "cache" property is mentioned to be also included along with soc specific compatible string.
>
> Please correct me if I am wrong here:
> So in order to retain the earlier description as Should have "sifive,<soc>-cache" and "cache",  I excluded "cache" property from example
> as I assumed it is implied for cacheinfo infrastructure to work properly.
> I will retain the earlier description (from.txt) which was "sifive,fu540-c000-ccache" and "cache"

You will need a custom 'select' schema to only match on
"sifive,fu540-c000-ccache". There's numerous examples in the tree.

Rob