On 07/25/2018 05:09 PM, Rob Herring wrote:
On Thu, Jul 19, 2018 at 11:55:13AM +0100, Suzuki K Poulose wrote:
The coresight drivers relied on default bindings for graph
in DT, while reusing the "reg" field of the "ports" to indicate
the actual hardware port number for the connections. This can
cause duplicate ports with same addresses, but different
direction. However, with the rules getting stricter w.r.t to the
address mismatch with the label, it is no longer possible to use
the port address field for the hardware port number.
This patch introduces new DT binding rules for coresight
components, based on the same generic DT graph bindings, but
avoiding the address duplication.
- All output ports must be specified under a child node with
name "out-ports".
- All input ports must be specified under a childe node with
name "in-ports".
- Port address should match the hardware port number.
The support for legacy bindings is retained, with a warning.
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
.../devicetree/bindings/arm/coresight.txt | 91 ++++++++++----------
drivers/hwtracing/coresight/of_coresight.c | 97 +++++++++++++++++++---
2 files changed, 129 insertions(+), 59 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
index 8e21512..f39d2c6 100644
--- a/Documentation/devicetree/bindings/arm/coresight.txt
+++ b/Documentation/devicetree/bindings/arm/coresight.txt
@@ -104,19 +104,9 @@ 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.
-
Why do you add this in the previous patch and then remove it here?
The only use case I can think of it is for someone to look back on the
legacy bindings, which were never documented. I could skip the parts
that are being removed.
Suzuki
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