[v3,2/7] dt-bindings: interconnect: Document the support of optional path tag

Commit Message

Georgi Djakov Sept. 3, 2020, 1:31 p.m. UTC

Let's document that we now support specifying path tag information in the
arg cells of the 'interconnects' DT property. This information would be
populated when the xlate_extended() callback is used.

Specifying the tag in DT will allow the interconnect framework to do the
aggregation based on the tag automatically. The users can still use the
icc_set_tag() API if/when needed.

Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Georgi Djakov <[e-mail]>
---
 .../bindings/interconnect/interconnect.txt    | 24 ++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

Patch

diff --git a/Documentation/devicetree/bindings/interconnect/interconnect.txt b/Documentation/devicetree/bindings/interconnect/interconnect.txt
index 6f5d23a605b7..138c544c8c8c 100644
--- a/Documentation/devicetree/bindings/interconnect/interconnect.txt
+++ b/Documentation/devicetree/bindings/interconnect/interconnect.txt
@@ -19,7 +19,8 @@  directly.
 Required properties:
 - compatible : contains the interconnect provider compatible string
 - #interconnect-cells : number of cells in a interconnect specifier needed to
-			encode the interconnect node id
+			encode the interconnect node id and optionally add a
+			path tag
 
 Example:
 
@@ -44,6 +45,10 @@  components it has to interact with.
 Required properties:
 interconnects : Pairs of phandles and interconnect provider specifier to denote
 	        the edge source and destination ports of the interconnect path.
+		An optional path tag value could specified as additional argument
+		to both endpoints and in such cases, this information will be passed
+		to the interconnect framework to do aggregation based on the attached
+		tag.
 
 Optional properties:
 interconnect-names : List of interconnect path name strings sorted in the same
@@ -62,3 +67,20 @@  Example:
 		interconnects = <&pnoc MASTER_SDCC_1 &bimc SLAVE_EBI_CH0>;
 		interconnect-names = "sdhc-mem";
 	};
+
+Example with path tags:
+
+	gnoc: interconnect@17900000 {
+		...
+		interconnect-cells = <2>;
+	};
+
+	mnoc: interconnect@1380000 {
+		...
+		interconnect-cells = <2>;
+	};
+
+	cpu@0 {
+		...
+		interconnects = <&gnoc MASTER_APPSS_PROC 3 &mnoc SLAVE_EBI1 3>;
+	}