[PATCH v2 01/12] dt-bindings: Add RISC-V trace component bindings

[Anup Patel]

Add device tree bindings for the memory mapped RISC-V trace components
which support both the RISC-V efficient trace (E-trace) protocol and
the RISC-V Nexus-based trace (N-trace) protocol.

The RISC-V trace components are defined by the RISC-V trace control
interface specification.

Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
 .../bindings/riscv/riscv,trace-component.yaml | 112 ++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml

diff --git a/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml b/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml
new file mode 100644
index 000000000000..7979af3d4174
--- /dev/null
+++ b/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml
@@ -0,0 +1,112 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/riscv/riscv,trace-component.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Trace Component
+
+maintainers:
+  - Anup Patel <anup at brainfault.org>
+
+description:
+  The RISC-V trace control interface specification standard memory mapped
+  components (or devices) which support both the RISC-V efficient trace
+  (E-trace) protocol and the RISC-V Nexus-based trace (N-trace) protocol.
+  The RISC-V trace components have implementation specific directed acyclic
+  graph style interdependency where output of one component serves as input
+  to another component and certain components (such as funnel) can take inputs
+  from multiple components. The type and version of a RISC-V trace component
+  can be discovered from it's IMPL memory mapped register hence component
+  specific compatible strings are not needed.
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qemu,trace-component
+      - const: riscv,trace-component
+
+  reg:
+    maxItems: 1
+
+  cpus:
+    maxItems: 1
+    description:
+      phandle to the cpu to which the RISC-V trace component is bound.
+
+  in-ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    patternProperties:
+      '^port(@[0-7])?$':
+        description: Input connections from RISC-V trace component
+        $ref: /schemas/graph.yaml#/properties/port
+
+  out-ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+    patternProperties:
+      '^port(@[0-7])?$':
+        description: Output connections from RISC-V trace component
+        $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1 (Per-hart encoder and ramsink components):
+
+    encoder at c000000 {
+      compatible = "qemu,trace-component", "riscv,trace-component";
+      reg = <0xc000000 0x1000>;
+      cpus = <&CPU0>;
+      out-ports {
+        port {
+          CPU0_ENCODER_OUTPUT: endpoint {
+            remote-endpoint = <&CPU0_RAMSINK_INPUT>;
+          };
+        };
+      };
+    };
+
+    ramsink at c001000 {
+      compatible = "qemu,trace-component", "riscv,trace-component";
+      reg = <0xc001000 0x1000>;
+      cpus = <&CPU0>;
+      in-ports {
+        port {
+          CPU0_RAMSINK_INPUT: endpoint {
+          };
+        };
+      };
+    };
+
+    encoder at c002000 {
+      compatible = "qemu,trace-component", "riscv,trace-component";
+      reg = <0xc002000 0x1000>;
+      cpus = <&CPU1>;
+      out-ports {
+        port {
+          CPU1_ENCODER_OUTPUT: endpoint {
+            remote-endpoint = <&CPU1_RAMSINK_INPUT>;
+          };
+        };
+      };
+    };
+
+    ramsink at c003000 {
+      compatible = "qemu,trace-component", "riscv,trace-component";
+      reg = <0xc003000 0x1000>;
+      cpus = <&CPU1>;
+      in-ports {
+        port {
+          CPU1_RAMSINK_INPUT: endpoint {
+          };
+        };
+      };
+    };
+
+...
-- 
2.43.0