1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/access-controllers/access-controllers.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Generic Domain Access Controllers
8
9 maintainers:
10 - Oleksii Moisieiev <oleksii_moisieiev@epam.com>
11
12 description: |+
13 Common access controllers properties
14
15 Access controllers are in charge of stating which of the hardware blocks under
16 their responsibility (their domain) can be accesssed by which compartment. A
17 compartment can be a cluster of CPUs (or coprocessors), a range of addresses
18 or a group of hardware blocks. An access controller's domain is the set of
19 resources covered by the access controller.
20
21 This device tree binding can be used to bind devices to their access
22 controller provided by access-controllers property. In this case, the device
23 is a consumer and the access controller is the provider.
24
25 An access controller can be represented by any node in the device tree and
26 can provide one or more configuration parameters, needed to control parameters
27 of the consumer device. A consumer node can refer to the provider by phandle
28 and a set of phandle arguments, specified by '#access-controller-cells'
29 property in the access controller node.
30
31 Access controllers are typically used to set/read the permissions of a
32 hardware block and grant access to it. Any of which depends on the access
33 controller. The capabilities of each access controller are defined by the
34 binding of the access controller device.
35
36 Each node can be a consumer for the several access controllers.
37
38 # always select the core schema
39 select: true
40
41 properties:
42 "#access-controller-cells":
43 description:
44 Number of cells in an access-controllers specifier;
45 Can be any value as specified by device tree binding documentation
46 of a particular provider. The node is an access controller.
47
48 access-controller-names:
49 $ref: /schemas/types.yaml#/definitions/string-array
50 description:
51 A list of access-controllers names, sorted in the same order as
52 access-controllers entries. Consumer drivers will use
53 access-controller-names to match with existing access-controllers entries.
54
55 access-controllers:
56 $ref: /schemas/types.yaml#/definitions/phandle-array
57 description:
58 A list of access controller specifiers, as defined by the
59 bindings of the access-controllers provider.
60
61 additionalProperties: true
62
63 examples:
64 - |
65 clock_controller: access-controllers@50000 {
66 reg = <0x50000 0x400>;
67 #access-controller-cells = <2>;
68 };
69
70 bus_controller: bus@60000 {
71 reg = <0x60000 0x10000>;
72 #address-cells = <1>;
73 #size-cells = <1>;
74 ranges;
75 #access-controller-cells = <3>;
76
77 uart4: serial@60100 {
78 reg = <0x60100 0x400>;
79 clocks = <&clk_serial>;
80 access-controllers = <&clock_controller 1 2>,
81 <&bus_controller 1 3 5>;
82 access-controller-names = "clock", "bus";
83 };
84 };
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