On Tue, Jun 05, 2018 at 10:43:18PM +0100, Suzuki K Poulose wrote:
Before we update the bindings, document the current graph bindings and usage of additional properties.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com
Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org
.../devicetree/bindings/arm/coresight.txt | 31 +++++++++++++++++++--- 1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt index 9aa30a1..ed6b555 100644 --- a/Documentation/devicetree/bindings/arm/coresight.txt +++ b/Documentation/devicetree/bindings/arm/coresight.txt @@ -52,9 +52,7 @@ its hardware characteristcs. clocks the core of that coresight component. The latter clock is optional.
- port or ports: The representation of the component's port
layout using the generic DT graph presentation found in"bindings/graph.txt".
- port or ports: see "Graph bindings for Coresight" below.
- Additional required properties for System Trace Macrocells (STM):
- reg: along with the physical base address and length of the register
@@ -71,7 +69,7 @@ its hardware characteristcs. AMBA markee): - "arm,coresight-replicator"
- port or ports: same as above.
- port or ports: see "Graph bindings for Coresight" below.
- Optional properties for ETM/PTMs:
@@ -90,6 +88,31 @@ its hardware characteristcs.
- arm,scatter-gather: boolean. Indicates that the TMC-ETR can safely use the SG mode on this system.
+Graph bindings for Coresight +-------------------------------
+Coresight components are interconnected to create a data path for the flow of +trace data generated from the "sources" to their collection points "sink". +Each coresight component must describe the "input" and "output" connections. +The connections must be described via generic DT graph bindings as described +by the "bindings/graph.txt", where each "port" along with an "endpoint" +component represents a hardware port and the connection.
+Since it is possible to have multiple connections for any coresight component +with a specific direction of data flow, each connection must define the +following properties to uniquely identify the connection details.
- Direction of the data flow w.r.t the component :
- Each input port must have the following property defined at the "endpoint"
- for the port.
- "slave-mode"
- Hardware Port number at the component:
- The hardware port number is assumed to be the address of the "port"component.Example:
- Sinks
-- 2.7.4