dt-bindings: sram: Convert SRAM bindings to json-schema

Generic on-chip SRAM

Simple IO memory regions to be managed by the genalloc API.

Required properties:

- compatible : mmio-sram or atmel,sama5d2-securam

- reg : SRAM iomem address range

Reserving sram areas:

---------------------

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.

Required properties in the sram node:

- #address-cells, #size-cells : should use the same values as the root node

- ranges : standard definition, should translate from local addresses

           within the sram to bus addresses

Optional properties in the sram node:

- no-memory-wc : the flag indicating, that SRAM memory region has not to

                 be remapped as write combining. WC is used by default.

Required properties in the area nodes:

- reg : iomem address range, relative to the SRAM range

Optional properties in the area nodes:

- compatible : standard definition, should contain a vendor specific string

               in the form <vendor>,[<device>-]<usage>

- pool : indicates that the particular reserved SRAM area is addressable

         and in use by another device or devices

- export : indicates that the reserved SRAM area may be accessed outside

           of the kernel, e.g. by bootloader or userspace

- protect-exec : Same as 'pool' above but with the additional

		 constraint that code wil 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.

- label : the name for the reserved partition, if omitted, the label

          is taken from the node name excluding the unit address.

- clocks : a list of phandle and clock specifier pair that controls the

	   single SRAM clock.

Example:

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;

	};

};

# 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:

  - Rob Herring <robh@kernel.org>

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:

    contains:

      enum:

        - mmio-sram

        - atmel,sama5d2-securam

  reg:

    maxItems: 1

  clocks:

    description:

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

      SRAM clock.

  "#address-cells":

    const: 1

  "#size-cells":

    const: 1

  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

patternProperties:

  "^([a-z]*-)?sram@[a-f0-9]+$":

    type: object

    description:

      Each child of the sram node specifies a region of reserved memory.

    properties:

      compatible:

        description:

          Should contain a vendor specific string in the form

          <vendor>,[<device>-]<usage>

      reg:

        description:

          IO mem address range, relative to the SRAM range.

        maxItems: 1

      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:

        description:

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

          from the node name excluding the unit address.

    required:

      - reg

    additionalProperties: false

required:

  - compatible

  - reg

  - "#address-cells"

  - "#size-cells"

  - ranges

additionalProperties: false

examples:

  - |

    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 {

            reg = <0x100 0x50>;

        };

        device-sram@1000 {

            reg = <0x1000 0x1000>;

            pool;

        };

        exported-sram@20000 {

            reg = <0x20000 0x20000>;

            export;

        };

    };