lkml.org 
[lkml]   [2018]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC PATCH 1/8] dts: binding: coresight: Document graph bindings
    Date
    Before we updat 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>
    ---
    .../devicetree/bindings/arm/coresight.txt | 28 ++++++++++++++++++----
    1 file changed, 24 insertions(+), 4 deletions(-)

    diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt
    index 15ac8e8..bd36e40 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:

    @@ -86,6 +84,28 @@ its hardware characteristcs.
    * arm,buffer-size: size of contiguous buffer space for TMC ETR
    (embedded trace router)

    +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:

    --
    2.7.4
    \
     
     \ /
      Last update: 2018-06-01 15:19    [W:7.792 / U:0.172 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site