xref: /linux/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml (revision e7e2296b0ecf9b6e934f7a1118cee91d4d486a84) 
1# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-source.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: ARM Coresight Dummy source component
8
9description: |
10  CoreSight components are compliant with the ARM CoreSight architecture
11  specification and can be connected in various topologies to suit a particular
12  SoCs tracing needs. These trace components can generally be classified as
13  sinks, links and sources. Trace data produced by one or more sources flows
14  through the intermediate links connecting the source to the currently selected
15  sink.
16
17  The Coresight dummy source component is for the specific coresight source
18  devices kernel don't have permission to access or configure. For some SOCs,
19  there would be Coresight source trace components on sub-processor which
20  are connected to AP processor via debug bus. For these devices, a dummy driver
21  is needed to register them as Coresight source devices, so that paths can be
22  created in the driver. It provides Coresight API for operations on dummy
23  source devices, such as enabling and disabling them. It also provides the
24  Coresight dummy source paths for debugging.
25
26  The primary use case of the coresight dummy source is to build path in kernel
27  side for dummy source component.
28
29maintainers:
30  - Mike Leach <mike.leach@linaro.org>
31  - Suzuki K Poulose <suzuki.poulose@arm.com>
32  - James Clark <james.clark@linaro.org>
33  - Mao Jinlong <quic_jinlmao@quicinc.com>
34  - Hao Zhang <quic_hazha@quicinc.com>
35
36properties:
37  compatible:
38    enum:
39      - arm,coresight-dummy-source
40
41  label:
42    description:
43      Description of a coresight device.
44
45  arm,static-trace-id:
46    description: If dummy source needs static id support, use this to set trace id.
47    $ref: /schemas/types.yaml#/definitions/uint32
48    minimum: 1
49    maximum: 111
50
51  out-ports:
52    $ref: /schemas/graph.yaml#/properties/ports
53
54    properties:
55      port:
56        description: Output connection from the source to Coresight
57          Trace bus.
58        $ref: /schemas/graph.yaml#/properties/port
59
60required:
61  - compatible
62  - out-ports
63
64additionalProperties: false
65
66examples:
67  # Minimum dummy source definition. Dummy source connect to coresight funnel.
68  - |
69    source {
70      compatible = "arm,coresight-dummy-source";
71
72      out-ports {
73        port {
74          dummy_riscv_out_funnel_swao: endpoint {
75            remote-endpoint = <&funnel_swao_in_dummy_riscv>;
76          };
77        };
78      };
79    };
80
81...
82