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

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 krzk@kernel.org

---

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 who@should.it.be

You can put me.

+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.

• 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).

• 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

•  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.

•    description:
  

•      The name for the reserved partition, if omitted, the label is taken
  

•      from the node name excluding the unit address.
  

•  clocks:
  

•    description:
  

•      A list of phandle and clock specifier pair that controls the
  

•      single SRAM clock.
  

•  # TODO: additionalProperties: false
  

• required:

•  - reg
  

+required:

• • compatible
• • reg
• • "#address-cells"
• • "#size-cells"
• • ranges

+examples:

• • |
• sram: sram@5c000000 {

•    compatible = "mmio-sram";
  

•    reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
  

•    #address-cells = <1>;
  

•    #size-cells = <1>;
  

•    ranges = <0 0x5c000000 0x40000>;
  

•    smp-sram@100 {
  

•        compatible = "socvendor,smp-sram";
  

•        reg = <0x100 0x50>;
  

•    };
  

•    device-sram@1000 {
  

•        reg = <0x1000 0x1000>;
  

•        pool;
  

•    };
  

•    exported@20000 {
  

•        reg = <0x20000 0x20000>;
  

•        export;
  

•    };
  

• };

-- 2.17.1