Subject: Re: [PATCH v2 2/8] dt-bindings: sram: Convert SRAM bindings to json-schema

From: Krzysztof Kozlowski <[email-masked]>
Date: Tue, 1 Oct 2019 17:24:22 +0200

On Tue, Oct 01, 2019 at 09:00:03AM -0500, Rob Herring wrote:
> On Wed, Sep 18, 2019 at 07:31:35PM +0200, Krzysztof Kozlowski wrote:
> > Convert generic mmio-sram bindings to DT schema format using
> > json-schema.
> 
> I've been slow getting to this because I started on the same thing...
> 
> > 
> > Signed-off-by: Krzysztof Kozlowski <[email-masked]>
> > 
> > ---
> > 
> > Changes since v1:
> > 1. Indent example with four spaces (more readable).
> > ---
> >  .../devicetree/bindings/sram/sram.txt         |  80 ----------
> >  .../devicetree/bindings/sram/sram.yaml        | 138 ++++++++++++++++++
> >  2 files changed, 138 insertions(+), 80 deletions(-)
> >  delete mode 100644 Documentation/devicetree/bindings/sram/sram.txt
> >  create mode 100644 Documentation/devicetree/bindings/sram/sram.yaml
> 
> > diff --git a/Documentation/devicetree/bindings/sram/sram.yaml b/Documentation/devicetree/bindings/sram/sram.yaml
> > new file mode 100644
> > index 000000000000..8d9d6ce494b2
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/sram/sram.yaml
> > @@ -0,0 +1,138 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/sram/sram.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Generic on-chip SRAM
> > +
> > +maintainers:
> > +  - FIXME <[email-masked]>
> 
> You can put me.

Sure.

> 
> > +
> > +description: |+
> > +  Simple IO memory regions to be managed by the genalloc API.
> > +
> > +  Each child of the sram node specifies a region of reserved memory. Each
> > +  child node should use a 'reg' property to specify a specific range of
> > +  reserved memory.
> > +
> > +  Following the generic-names recommended practice, node names should
> > +  reflect the purpose of the node. Unit address (@<address>) should be
> > +  appended to the name.
> > +
> > +properties:
> > +  $nodename:
> > +    pattern: "^sram(@.*)?"
> > +
> > +  compatible:
> > +    items:
> > +      - enum:
> > +          - mmio-sram
> > +          - atmel,sama5d2-securam
> 
> I was trying to go down the path of putting all the compatibles for 
> various SRAM bindings here, but I ran into some issues. I need to 
> revisit as I've forgotten the exact issue.
> 
> This would need to be a 'contains' if this is going to work for others.

OK.

> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  "#address-cells":
> > +    description: Should use the same values as the root node.
> > +
> > +  "#size-cells":
> > +    description: Should use the same values as the root node.
> 
> I defined both of these to be 1 as 4GB of SRAM should be enough for a 
> while. We can debate 1 or 2 cells vs. 1, but there's no reason it has to 
> be the same as the root (unless we're failing to do address 
> translation).

That was copied from txt version. I can adjust them to 1 although this
is will more than simple conversion.

> 
> > +
> > +  ranges:
> > +    description:
> > +      Should translate from local addresses within the sram to bus addresses.
> > +
> > +  no-memory-wc:
> > +    description:
> > +      The flag indicating, that SRAM memory region has not to be remapped
> > +      as write combining. WC is used by default.
> > +    type: boolean
> > +
> > +  # TODO: additionalProperties: false
> > +
> > +patternProperties:
> > +  "^([a-z]*-)?sram@[a-f0-9]$":
> > +    type: object
> > +    description:
> > +      Each child of the sram node specifies a region of reserved memory.
> > +    properties:
> > +      reg:
> > +        description:
> > +          IO mem address range, relative to the SRAM range.
> 
> maxItems: 1

OK

> 
> > +
> > +      compatible:
> > +        $ref: /schemas/types.yaml#/definitions/string
> > +        description:
> > +          Should contain a vendor specific string in the form
> > +          <vendor>,[<device>-]<usage>
> > +
> > +      pool:
> > +        description:
> > +          Indicates that the particular reserved SRAM area is addressable
> > +          and in use by another device or devices.
> > +        type: boolean
> > +
> > +      export:
> > +        description:
> > +          Indicates that the reserved SRAM area may be accessed outside
> > +          of the kernel, e.g. by bootloader or userspace.
> > +        type: boolean
> > +
> > +      protect-exec:
> > +        description: |
> > +          Same as 'pool' above but with the additional constraint that code
> > +          will be run from the region and that the memory is maintained as
> > +          read-only, executable during code execution. NOTE: This region must
> > +          be page aligned on start and end in order to properly allow
> > +          manipulation of the page attributes.
> > +        type: boolean
> > +
> > +      label:
> > +        $ref: /schemas/types.yaml#/definitions/string
> 
> Already has a type definition.

OK

Best regards,
Krzysztof

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