On Fri, Jun 01, 2018 at 02:16:05PM +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. 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. Hence, we add an explicit
property to denote the hardware port number, "coresight,hwid"
which must be specified for each "endpoint".
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 | 26 +++++++++---
drivers/hwtracing/coresight/of_coresight.c | 46 ++++++++++++++++------
2 files changed, 54 insertions(+), 18 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
index bd36e40..385581a 100644
--- a/Documentation/devicetree/bindings/arm/coresight.txt
+++ b/Documentation/devicetree/bindings/arm/coresight.txt
@@ -104,7 +104,11 @@ properties to uniquely identify the connection details.
"slave-mode"
* Hardware Port number at the component:
- - The hardware port number is assumed to be the address of the "port" component.
+ - (Obsolete) The hardware port number is assumed to be the address of the "port" component.
+ - Each "endpoint" must define the hardware port of the local end of the
+ connection using the following property:
+ "coresight,hwid" - 32bit integer, hardware port number at the local end.
"coresight" is not a vendor and properties are in the form
[<vendor>,]<prop-name>.
+
Example:
@@ -120,6 +124,7 @@ Example:
etb_in_port: endpoint@0 {
There shouldn't be a unit address here because there is no reg property.
slave-mode;
remote-endpoint = <&replicator_out_port0>;
+ coresight,hwid = <0>;
It doesn't make sense for these to be in the endpoint. If you had
multiple endpoints, then you would have to duplicate it. "ports" are
a single data stream. "endpoints" are connections to that stream. So if
you have a muxed (input) or fanout/1-to-many (output) connection, then
you have multiple endpoints.
The same applied to the slave-mode property, but that ship has sailed.
No reason to continue that though.
};
};
};
@@ -134,6 +139,7 @@ Example:
tpiu_in_port: endpoint@0 {
slave-mode;
remote-endpoint = <&replicator_out_port1>;
+ coresight,hwid = <0>;
};
};
};
@@ -154,6 +160,7 @@ Example:
reg = <0>;
replicator_out_port0: endpoint {
remote-endpoint = <&etb_in_port>;
+ coresight,hwid = <0>;
};
};
@@ -161,15 +168,17 @@ Example:
reg = <1>;
replicator_out_port1: endpoint {
remote-endpoint = <&tpiu_in_port>;
+ coresight,hwid = <1>;
};
};
/* replicator input port */
port@2 {
- reg = <0>;
+ reg = <1>;
This will still get flagged as an error. reg must be 2 here.