diff mbox series

[V2,06/11] dts: bindings: Document device tree bindings for ETE

Message ID 1610511498-4058-7-git-send-email-anshuman.khandual@arm.com
State Superseded
Headers show
Series None | expand

Commit Message

Anshuman Khandual Jan. 13, 2021, 4:18 a.m. UTC
From: Suzuki K Poulose <suzuki.poulose@arm.com>


Document the device tree bindings for Embedded Trace Extensions.
ETE can be connected to legacy coresight components and thus
could optionally contain a connection graph as described by
the CoreSight bindings.

Cc: devicetree@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

---
 Documentation/devicetree/bindings/arm/ete.yaml | 71 ++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml

-- 
2.7.4

Comments

Rob Herring (Arm) Jan. 25, 2021, 7:22 p.m. UTC | #1
On Wed, Jan 13, 2021 at 09:48:13AM +0530, Anshuman Khandual wrote:
> From: Suzuki K Poulose <suzuki.poulose@arm.com>

> 

> Document the device tree bindings for Embedded Trace Extensions.

> ETE can be connected to legacy coresight components and thus

> could optionally contain a connection graph as described by

> the CoreSight bindings.

> 

> Cc: devicetree@vger.kernel.org

> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>

> Cc: Mike Leach <mike.leach@linaro.org>

> Cc: Rob Herring <robh@kernel.org>

> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

> ---

>  Documentation/devicetree/bindings/arm/ete.yaml | 71 ++++++++++++++++++++++++++

>  1 file changed, 71 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml

> 

> diff --git a/Documentation/devicetree/bindings/arm/ete.yaml b/Documentation/devicetree/bindings/arm/ete.yaml

> new file mode 100644

> index 0000000..00e6a77

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/arm/ete.yaml

> @@ -0,0 +1,71 @@

> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause

> +# Copyright 2021, Arm Ltd

> +%YAML 1.2

> +---

> +$id: "http://devicetree.org/schemas/arm/ete.yaml#"

> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"

> +

> +title: ARM Embedded Trace Extensions

> +

> +maintainers:

> +  - Suzuki K Poulose <suzuki.poulose@arm.com>

> +  - Mathieu Poirier <mathieu.poirier@linaro.org>

> +

> +description: |

> +  Arm Embedded Trace Extension(ETE) is a per CPU trace component that

> +  allows tracing the CPU execution. It overlaps with the CoreSight ETMv4

> +  architecture and has extended support for future architecture changes.

> +  The trace generated by the ETE could be stored via legacy CoreSight

> +  components (e.g, TMC-ETR) or other means (e.g, using a per CPU buffer

> +  Arm Trace Buffer Extension (TRBE)). Since the ETE can be connected to

> +  legacy CoreSight components, a node must be listed per instance, along

> +  with any optional connection graph as per the coresight bindings.

> +  See bindings/arm/coresight.txt.

> +

> +properties:

> +  $nodename:

> +    pattern: "^ete([0-9a-f]+)$"

> +  compatible:

> +    items:

> +      - const: arm,embedded-trace-extension

> +

> +  cpu:


We use 'cpus' in a couple of other places, let's do that here for 
consistency.

> +    description: |

> +      Handle to the cpu this ETE is bound to.

> +    $ref: /schemas/types.yaml#/definitions/phandle

> +

> +  out-ports:

> +    description: |

> +      Out put connections from the ETE to legacy CoreSight trace bus.


Output

> +    $ref: /schemas/graph.yaml#/properties/ports


You have to define what each 'port' is if there can be more than 1. If 
there's only ever 1 then you just need 'port' though maybe all the 
coresight bindings require 'out-ports'. And the port nodes need a $ref 
to '/schemas/graph.yaml#/properties/port'.

> +

> +required:

> +  - compatible

> +  - cpu

> +

> +additionalProperties: false

> +

> +examples:

> +

> +# An ETE node without legacy CoreSight connections

> +  - |

> +    ete0 {

> +      compatible = "arm,embedded-trace-extension";

> +      cpu = <&cpu_0>;

> +    };

> +# An ETE node with legacy CoreSight connections

> +  - |

> +   ete1 {

> +      compatible = "arm,embedded-trace-extension";

> +      cpu = <&cpu_1>;

> +

> +      out-ports {        /* legacy coresight connection */

> +         port {

> +             ete1_out_port: endpoint {

> +                remote-endpoint = <&funnel_in_port0>;

> +             };

> +         };

> +      };

> +   };

> +

> +...

> -- 

> 2.7.4

>
Suzuki K Poulose Jan. 25, 2021, 10:20 p.m. UTC | #2
Hi Rob

On 1/25/21 7:22 PM, Rob Herring wrote:
> On Wed, Jan 13, 2021 at 09:48:13AM +0530, Anshuman Khandual wrote:

>> From: Suzuki K Poulose <suzuki.poulose@arm.com>

>>

>> Document the device tree bindings for Embedded Trace Extensions.

>> ETE can be connected to legacy coresight components and thus

>> could optionally contain a connection graph as described by

>> the CoreSight bindings.

>>

>> Cc: devicetree@vger.kernel.org

>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>

>> Cc: Mike Leach <mike.leach@linaro.org>

>> Cc: Rob Herring <robh@kernel.org>

>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

>> ---

>>   Documentation/devicetree/bindings/arm/ete.yaml | 71 ++++++++++++++++++++++++++

>>   1 file changed, 71 insertions(+)

>>   create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml

>>

>> diff --git a/Documentation/devicetree/bindings/arm/ete.yaml b/Documentation/devicetree/bindings/arm/ete.yaml

>> new file mode 100644

>> index 0000000..00e6a77

>> --- /dev/null

>> +++ b/Documentation/devicetree/bindings/arm/ete.yaml

>> @@ -0,0 +1,71 @@

>> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause

>> +# Copyright 2021, Arm Ltd

>> +%YAML 1.2

>> +---

>> +$id: "http://devicetree.org/schemas/arm/ete.yaml#"

>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"

>> +

>> +title: ARM Embedded Trace Extensions

>> +

>> +maintainers:

>> +  - Suzuki K Poulose <suzuki.poulose@arm.com>

>> +  - Mathieu Poirier <mathieu.poirier@linaro.org>

>> +

>> +description: |

>> +  Arm Embedded Trace Extension(ETE) is a per CPU trace component that

>> +  allows tracing the CPU execution. It overlaps with the CoreSight ETMv4

>> +  architecture and has extended support for future architecture changes.

>> +  The trace generated by the ETE could be stored via legacy CoreSight

>> +  components (e.g, TMC-ETR) or other means (e.g, using a per CPU buffer

>> +  Arm Trace Buffer Extension (TRBE)). Since the ETE can be connected to

>> +  legacy CoreSight components, a node must be listed per instance, along

>> +  with any optional connection graph as per the coresight bindings.

>> +  See bindings/arm/coresight.txt.

>> +

>> +properties:

>> +  $nodename:

>> +    pattern: "^ete([0-9a-f]+)$"

>> +  compatible:

>> +    items:

>> +      - const: arm,embedded-trace-extension

>> +

>> +  cpu:

> 

> We use 'cpus' in a couple of other places, let's do that here for

> consistency.


This is following the existing CoreSight bindings for ETM. The same driver
probes both. Also there can only ever be a single CPU for ete/etm. So, we
would prefer to keep it aligned with the existing bindings to avoid causing
confusion.

> 

>> +    description: |

>> +      Handle to the cpu this ETE is bound to.

>> +    $ref: /schemas/types.yaml#/definitions/phandle

>> +

>> +  out-ports:

>> +    description: |

>> +      Out put connections from the ETE to legacy CoreSight trace bus.

> 

> Output


Will fix.

> 

>> +    $ref: /schemas/graph.yaml#/properties/ports

> 

> You have to define what each 'port' is if there can be more than 1. If

> there's only ever 1 then you just need 'port' though maybe all the

> coresight bindings require 'out-ports'. And the port nodes need a $ref

> to '/schemas/graph.yaml#/properties/port'.


All CoreSight components require an out-ports and/or in-ports. The ETM/ETE
always has one port, but must be under out-ports in line with the CoreSight
bindings.

Does this look more apt:

    out-ports:
      description: |
        Output connection from the ETE to legacy CoreSight trace bus.
      poperties:
         port:
           $ref: /schemas/graph.yaml#/properties/port

Suzuki
Suzuki K Poulose Jan. 25, 2021, 11:28 p.m. UTC | #3
On 1/25/21 10:20 PM, Suzuki K Poulose wrote:
> Hi Rob

> 

> On 1/25/21 7:22 PM, Rob Herring wrote:

>> On Wed, Jan 13, 2021 at 09:48:13AM +0530, Anshuman Khandual wrote:

>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>

>>>

>>> Document the device tree bindings for Embedded Trace Extensions.

>>> ETE can be connected to legacy coresight components and thus

>>> could optionally contain a connection graph as described by

>>> the CoreSight bindings.

>>>

>>> Cc: devicetree@vger.kernel.org

>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>

>>> Cc: Mike Leach <mike.leach@linaro.org>

>>> Cc: Rob Herring <robh@kernel.org>

>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

>>> ---

>>>   Documentation/devicetree/bindings/arm/ete.yaml | 71 ++++++++++++++++++++++++++

>>>   1 file changed, 71 insertions(+)

>>>   create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml

>>>

>>> diff --git a/Documentation/devicetree/bindings/arm/ete.yaml 

>>> b/Documentation/devicetree/bindings/arm/ete.yaml

>>> new file mode 100644

>>> index 0000000..00e6a77

>>> --- /dev/null

>>> +++ b/Documentation/devicetree/bindings/arm/ete.yaml

>>> @@ -0,0 +1,71 @@

>>> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause

>>> +# Copyright 2021, Arm Ltd

>>> +%YAML 1.2

>>> +---

>>> +$id: "http://devicetree.org/schemas/arm/ete.yaml#"

>>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"

>>> +

>>> +title: ARM Embedded Trace Extensions

>>> +

>>> +maintainers:

>>> +  - Suzuki K Poulose <suzuki.poulose@arm.com>

>>> +  - Mathieu Poirier <mathieu.poirier@linaro.org>

>>> +

>>> +description: |

>>> +  Arm Embedded Trace Extension(ETE) is a per CPU trace component that

>>> +  allows tracing the CPU execution. It overlaps with the CoreSight ETMv4

>>> +  architecture and has extended support for future architecture changes.

>>> +  The trace generated by the ETE could be stored via legacy CoreSight

>>> +  components (e.g, TMC-ETR) or other means (e.g, using a per CPU buffer

>>> +  Arm Trace Buffer Extension (TRBE)). Since the ETE can be connected to

>>> +  legacy CoreSight components, a node must be listed per instance, along

>>> +  with any optional connection graph as per the coresight bindings.

>>> +  See bindings/arm/coresight.txt.

>>> +

>>> +properties:

>>> +  $nodename:

>>> +    pattern: "^ete([0-9a-f]+)$"

>>> +  compatible:

>>> +    items:

>>> +      - const: arm,embedded-trace-extension

>>> +

>>> +  cpu:

>>

>> We use 'cpus' in a couple of other places, let's do that here for

>> consistency.

> 

> This is following the existing CoreSight bindings for ETM. The same driver

> probes both. Also there can only ever be a single CPU for ete/etm. So, we

> would prefer to keep it aligned with the existing bindings to avoid causing

> confusion.

> 

>>

>>> +    description: |

>>> +      Handle to the cpu this ETE is bound to.

>>> +    $ref: /schemas/types.yaml#/definitions/phandle

>>> +

>>> +  out-ports:

>>> +    description: |

>>> +      Out put connections from the ETE to legacy CoreSight trace bus.

>>

>> Output

> 

> Will fix.

> 

>>

>>> +    $ref: /schemas/graph.yaml#/properties/ports

>>

>> You have to define what each 'port' is if there can be more than 1. If

>> there's only ever 1 then you just need 'port' though maybe all the

>> coresight bindings require 'out-ports'. And the port nodes need a $ref

>> to '/schemas/graph.yaml#/properties/port'.

> 

> All CoreSight components require an out-ports and/or in-ports. The ETM/ETE

> always has one port, but must be under out-ports in line with the CoreSight

> bindings.

> 

> Does this look more apt:

> 

>     out-ports:

>       description: |

>         Output connection from the ETE to legacy CoreSight trace bus.

>       poperties:

>          port:

>            $ref: /schemas/graph.yaml#/properties/port



Correction, the above should be :

+  out-ports:
+    type: object
+    description: |
+      Output connections from the ETE to legacy CoreSight trace bus.
+    properties:
+      port:
+        $ref: /schemas/graph.yaml#/properties/port


That works fine for me. Does that look fine ?  Some day, we should convert the
coresight dt bindings to yaml and import the out-ports/in-ports from the scheme :-)

Cheers
Suzuki
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/arm/ete.yaml b/Documentation/devicetree/bindings/arm/ete.yaml
new file mode 100644
index 0000000..00e6a77
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/ete.yaml
@@ -0,0 +1,71 @@ 
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+# Copyright 2021, Arm Ltd
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/arm/ete.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: ARM Embedded Trace Extensions
+
+maintainers:
+  - Suzuki K Poulose <suzuki.poulose@arm.com>
+  - Mathieu Poirier <mathieu.poirier@linaro.org>
+
+description: |
+  Arm Embedded Trace Extension(ETE) is a per CPU trace component that
+  allows tracing the CPU execution. It overlaps with the CoreSight ETMv4
+  architecture and has extended support for future architecture changes.
+  The trace generated by the ETE could be stored via legacy CoreSight
+  components (e.g, TMC-ETR) or other means (e.g, using a per CPU buffer
+  Arm Trace Buffer Extension (TRBE)). Since the ETE can be connected to
+  legacy CoreSight components, a node must be listed per instance, along
+  with any optional connection graph as per the coresight bindings.
+  See bindings/arm/coresight.txt.
+
+properties:
+  $nodename:
+    pattern: "^ete([0-9a-f]+)$"
+  compatible:
+    items:
+      - const: arm,embedded-trace-extension
+
+  cpu:
+    description: |
+      Handle to the cpu this ETE is bound to.
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  out-ports:
+    description: |
+      Out put connections from the ETE to legacy CoreSight trace bus.
+    $ref: /schemas/graph.yaml#/properties/ports
+
+required:
+  - compatible
+  - cpu
+
+additionalProperties: false
+
+examples:
+
+# An ETE node without legacy CoreSight connections
+  - |
+    ete0 {
+      compatible = "arm,embedded-trace-extension";
+      cpu = <&cpu_0>;
+    };
+# An ETE node with legacy CoreSight connections
+  - |
+   ete1 {
+      compatible = "arm,embedded-trace-extension";
+      cpu = <&cpu_1>;
+
+      out-ports {        /* legacy coresight connection */
+         port {
+             ete1_out_port: endpoint {
+                remote-endpoint = <&funnel_in_port0>;
+             };
+         };
+      };
+   };
+
+...