[PATCH RFC 01/12] dt-bindings: riscv: Add SiFive pre-ratified trace components

[Eric Lin]

Add compatible strings for the SiFive pre-ratified encoder and funnel
trace components. These implement version 0.x of the RISC-V trace
specification and do not support the generic riscv,trace-component
fallback.

Co-developed-by: Nick Hu <nick.hu at sifive.com>
Signed-off-by: Nick Hu <nick.hu at sifive.com>
Co-developed-by: Vincent Chen <vincent.chen at sifive.com>
Signed-off-by: Vincent Chen <vincent.chen at sifive.com>
Signed-off-by: Eric Lin <eric.lin at sifive.com>
---
 .../bindings/riscv/riscv,trace-component.yaml      | 73 +++++++++++++++++++---
 1 file changed, 66 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml b/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml
index bb519bc4a163..70c8d257b46f 100644
--- a/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml
+++ b/Documentation/devicetree/bindings/riscv/riscv,trace-component.yaml
@@ -16,16 +16,23 @@ description:
   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.
+  from multiple components. While the type and version of a RISC-V trace component
+  can be discovered from it's IMPL memory mapped register, specific compatible strings
+  are used for pre-ratified trace components.
 
 properties:
   compatible:
-    items:
-      - enum:
-          - qemu,trace-component
-      - const: riscv,trace-component
+    oneOf:
+      - items:
+          - enum:
+              - qemu,trace-component
+          - const: riscv,trace-component
+      - items:
+          - const: sifive,trace-encoder0
+        description: SiFive Pre-ratified Encoder Trace Component
+      - items:
+          - const: sifive,trace-funnel0
+        description: SiFive Pre-ratified Funnel Trace Component
 
   reg:
     maxItems: 1
@@ -117,4 +124,56 @@ examples:
       };
     };
 
+  - |
+    // Example 2: SiFive trace encoder and funnel connection
+    encoder-0 at 2000000 {
+        compatible = "sifive,trace-encoder0";
+        reg = <0x2000000 0x1000>;
+        cpus = <&CPU0>;
+
+        out-ports {
+            port {
+                encoder0_out: endpoint {
+                  remote-endpoint = <&funnel_in0>;
+                };
+            };
+        };
+    };
+
+    encoder-1 at 2001000 {
+        compatible = "sifive,trace-encoder0";
+        reg = <0x2001000 0x1000>;
+        cpus = <&CPU1>;
+
+        out-ports {
+            port {
+                encoder1_out: endpoint {
+                  remote-endpoint = <&funnel_in1>;
+                };
+            };
+        };
+    };
+
+    funnel-0 at 2002000 {
+        compatible = "sifive,trace-funnel0";
+        reg = <0x2002000 0x1000>;
+
+        in-ports {
+            #address-cells = <1>;
+            #size-cells = <0>;
+            port at 0 {
+                reg = <0x0>;
+                funnel_in0: endpoint {
+                    remote-endpoint = <&encoder0_out>;
+                };
+            };
+
+            port at 1 {
+                reg = <0x1>;
+                funnel_in1: endpoint {
+                    remote-endpoint = <&encoder1_out>;
+                };
+            };
+        };
+    };
 ...

-- 
2.34.1