xref: /freebsd/sys/contrib/device-tree/Bindings/access-controllers/access-controllers.yaml (revision 7d0873ebb83b19ba1e8a89e679470d885efe12e3)

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/access-controllers/access-controllers.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Generic Domain Access Controllers

maintainers:
  - Oleksii Moisieiev <oleksii_moisieiev@epam.com>

description: |+
  Common access controllers properties

  Access controllers are in charge of stating which of the hardware blocks under
  their responsibility (their domain) can be accesssed by which compartment. A
  compartment can be a cluster of CPUs (or coprocessors), a range of addresses
  or a group of hardware blocks. An access controller's domain is the set of
  resources covered by the access controller.

  This device tree binding can be used to bind devices to their access
  controller provided by access-controllers property. In this case, the device
  is a consumer and the access controller is the provider.

  An access controller can be represented by any node in the device tree and
  can provide one or more configuration parameters, needed to control parameters
  of the consumer device. A consumer node can refer to the provider by phandle
  and a set of phandle arguments, specified by '#access-controller-cells'
  property in the access controller node.

  Access controllers are typically used to set/read the permissions of a
  hardware block and grant access to it. Any of which depends on the access
  controller. The capabilities of each access controller are defined by the
  binding of the access controller device.

  Each node can be a consumer for the several access controllers.

# always select the core schema
select: true

properties:
  "#access-controller-cells":
    description:
      Number of cells in an access-controllers specifier;
      Can be any value as specified by device tree binding documentation
      of a particular provider. The node is an access controller.

  access-controller-names:
    $ref: /schemas/types.yaml#/definitions/string-array
    description:
      A list of access-controllers names, sorted in the same order as
      access-controllers entries. Consumer drivers will use
      access-controller-names to match with existing access-controllers entries.

  access-controllers:
    $ref: /schemas/types.yaml#/definitions/phandle-array
    description:
      A list of access controller specifiers, as defined by the
      bindings of the access-controllers provider.

additionalProperties: true

examples:
  - |
    clock_controller: access-controllers@50000 {
        reg = <0x50000 0x400>;
        #access-controller-cells = <2>;
    };

    bus_controller: bus@60000 {
        reg = <0x60000 0x10000>;
        #address-cells = <1>;
        #size-cells = <1>;
        ranges;
        #access-controller-cells = <3>;

        uart4: serial@60100 {
            reg = <0x60100 0x400>;
            clocks = <&clk_serial>;
            access-controllers = <&clock_controller 1 2>,
                                 <&bus_controller 1 3 5>;
            access-controller-names = "clock", "bus";
        };
    };