[PATCH v6 0/3] Add support to configure Coresight Dummy subunit

[PATCH v6 0/3] Add support to configure Coresight Dummy subunit

[Hao Zhang]

Introduction of Coresight Dummy subunit
The Coresight Dummy subunit is for Coresight Dummy component, there are
some specific Coresight devices that HLOS don't have permission to access.
Such as some TPDMs, they would be configured in NON-HLOS side, but it's
necessary to build Coresight path for it to debug. So there need driver to
register dummy devices as Coresight devices.

Commit link:
https://git.codelinaro.org/clo/linux-kernel/coresight/-/tree/coresight-dummy-v6

Changes in V6:
1. Add the missing information and update the patch version.

Changes in V5:
1. Follow the alphabetical order for the header files in
coresight-dummy.c. -- Suzuki K Poulose
2. Update the maintainers.
3. Split the Coresight Dummy YAML to 2 schema files. 
-- Rob Herring & Krzysztof Kozlowski
4. Update the coresight-dummy.rst file. -- Bagas Sanjaya

Changes in V4:
1. Remove traceid allocation in dummy_probe function since it is
currently not in use, will upstream it as the part of ATID filtering
in the further.  -- Suzuki K Poulose
2. Remove 'oneOf' as there is only one entry. -- Rob Herring

Changes in V3:
1. Use API "dev_dbg" to replace "dev_info". -- Suzuki K Poulose
2. Drop "qcom" property and take it as a dummy framework.
-- Suzuki K Poulose
3. Add new sub-type "CORESIGHT_DEV_SUBTYPE_SINK_DUMMY" to support
coresight dummy module -- Mike Leach
4. Use compatibles "arm,coresight-dummy-source" and
"arm,coresight-dummy-sink" to replace property "qcom,dummy-source" and
"qcom,dummy-sink". -- Mike Leach
5. Define source_devs and sink_devs DEVLIST to replace dummy_devs, make
it clear at the first level. -- Mike Leach
6. Modify subject of YAML patch, drop "YAML schema". -- Krzysztof Kozlowski
7. Drop some redundant items and correct syntax errors in yaml file.
-- Krzysztof Kozlowski & Rob Herring
8. Correct required property of yaml file, constrain out ports to
dummy-source and in ports to dummy-sink. -- Mike Leach
9. Drop "Sysfs files and directories" contents of coresight-dummy.rst.
-- Suzuki K Poulose/Greg Kroah-Hartman
10.Correct syntax errors of coresight-dummy.rst. -- Bagas Sanjaya

Changes in V2:
1. Declare dummy_init and dummy_exit as static to fix missing-prototypes
warnings. -- kernel test robot
2. Fix the errors of coresight-dummy yaml file. -- Rob Herring

Hao Zhang (3):
  Coresight: Add coresight dummy driver
  dt-bindings: arm: Add support for Coresight dummy trace
  Documentation: trace: Add documentation for Coresight Dummy Trace

 .../arm/arm,coresight-dummy-sink.yaml         |  73 ++++++++
 .../arm/arm,coresight-dummy-source.yaml       |  71 ++++++++
 .../trace/coresight/coresight-dummy.rst       |  32 ++++
 drivers/hwtracing/coresight/Kconfig           |  11 ++
 drivers/hwtracing/coresight/Makefile          |   1 +
 drivers/hwtracing/coresight/coresight-dummy.c | 163 ++++++++++++++++++
 include/linux/coresight.h                     |   1 +
 7 files changed, 352 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
 create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
 create mode 100644 Documentation/trace/coresight/coresight-dummy.rst
 create mode 100644 drivers/hwtracing/coresight/coresight-dummy.c

-- 
2.17.1

[PATCH v6 1/3] Coresight: Add coresight dummy driver

[Hao Zhang]

Some Coresight devices that kernel don't have permission to access or
configure. For these devices, a dummy driver is needed to register them as
Coresight devices. The module may also be used to define components that
may not have any programming interfaces, so that paths can be created
in the driver. It provides Coresight API for operations on dummy devices,
such as enabling and disabling them. It also provides the Coresight dummy
sink/source paths for debugging.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
---
 drivers/hwtracing/coresight/Kconfig           |  11 ++
 drivers/hwtracing/coresight/Makefile          |   1 +
 drivers/hwtracing/coresight/coresight-dummy.c | 163 ++++++++++++++++++
 include/linux/coresight.h                     |   1 +
 4 files changed, 176 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-dummy.c

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 2b5bbfffbc4f..06f0a7594169 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -236,4 +236,15 @@ config CORESIGHT_TPDA
 
 	  To compile this driver as a module, choose M here: the module will be
 	  called coresight-tpda.
+
+config CORESIGHT_DUMMY
+	tristate "Dummy driver support"
+	help
+	  Enables support for dummy driver. Dummy driver can be used for
+	  CoreSight sources/sinks that are owned and configured by some
+	  other subsystem and use Linux drivers to configure rest of trace
+	  path.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called coresight-dummy.
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 33bcc3f7b8ae..995d3b2c76df 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
 coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
 		   coresight-cti-sysfs.o
 obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o
+obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c
new file mode 100644
index 000000000000..42125b7a0f39
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-dummy.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/coresight.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include "coresight-priv.h"
+
+struct dummy_drvdata {
+	struct device			*dev;
+	struct coresight_device		*csdev;
+};
+
+DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
+DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");
+
+static int dummy_source_enable(struct coresight_device *csdev,
+			       struct perf_event *event, u32 mode)
+{
+	dev_dbg(csdev->dev.parent, "Dummy source enabled\n");
+
+	return 0;
+}
+
+static void dummy_source_disable(struct coresight_device *csdev,
+				 struct perf_event *event)
+{
+	dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
+}
+
+static int dummy_sink_enable(struct coresight_device *csdev, u32 mode,
+				void *data)
+{
+	dev_dbg(csdev->dev.parent, "Dummy sink enabled\n");
+
+	return 0;
+}
+
+static int dummy_sink_disable(struct coresight_device *csdev)
+{
+	dev_dbg(csdev->dev.parent, "Dummy sink disabled\n");
+
+	return 0;
+}
+
+static const struct coresight_ops_source dummy_source_ops = {
+	.enable	= dummy_source_enable,
+	.disable = dummy_source_disable,
+};
+
+static const struct coresight_ops dummy_source_cs_ops = {
+	.source_ops = &dummy_source_ops,
+};
+
+static const struct coresight_ops_sink dummy_sink_ops = {
+	.enable	= dummy_sink_enable,
+	.disable = dummy_sink_disable,
+};
+
+static const struct coresight_ops dummy_sink_cs_ops = {
+	.sink_ops = &dummy_sink_ops,
+};
+
+static int dummy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct coresight_platform_data *pdata;
+	struct dummy_drvdata *drvdata;
+	struct coresight_desc desc = { 0 };
+
+	if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
+
+		desc.name = coresight_alloc_device_name(&source_devs, dev);
+		if (!desc.name)
+			return -ENOMEM;
+
+		desc.type = CORESIGHT_DEV_TYPE_SOURCE;
+		desc.subtype.source_subtype =
+					CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
+		desc.ops = &dummy_source_cs_ops;
+	} else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) {
+		desc.name = coresight_alloc_device_name(&sink_devs, dev);
+		if (!desc.name)
+			return -ENOMEM;
+
+		desc.type = CORESIGHT_DEV_TYPE_SINK;
+		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_DUMMY;
+		desc.ops = &dummy_sink_cs_ops;
+	} else {
+		dev_err(dev, "Device type not set\n");
+		return -EINVAL;
+	}
+
+	pdata = coresight_get_platform_data(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+	pdev->dev.platform_data = pdata;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	desc.pdata = pdev->dev.platform_data;
+	desc.dev = &pdev->dev;
+	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev))
+		return PTR_ERR(drvdata->csdev);
+
+	pm_runtime_enable(dev);
+	dev_dbg(dev, "Dummy device initialized\n");
+
+	return 0;
+}
+
+static int dummy_remove(struct platform_device *pdev)
+{
+	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_disable(dev);
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
+static const struct of_device_id dummy_match[] = {
+	{.compatible = "arm,coresight-dummy-source"},
+	{.compatible = "arm,coresight-dummy-sink"},
+	{},
+};
+
+static struct platform_driver dummy_driver = {
+	.probe	= dummy_probe,
+	.remove	= dummy_remove,
+	.driver	= {
+		.name   = "coresight-dummy",
+		.of_match_table = dummy_match,
+	},
+};
+
+static int __init dummy_init(void)
+{
+	return platform_driver_register(&dummy_driver);
+}
+module_init(dummy_init);
+
+static void __exit dummy_exit(void)
+{
+	platform_driver_unregister(&dummy_driver);
+}
+module_exit(dummy_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight dummy driver");
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index f19a47b9bb5a..6db4b49751cf 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -45,6 +45,7 @@ enum coresight_dev_type {
 };
 
 enum coresight_dev_subtype_sink {
+	CORESIGHT_DEV_SUBTYPE_SINK_DUMMY,
 	CORESIGHT_DEV_SUBTYPE_SINK_PORT,
 	CORESIGHT_DEV_SUBTYPE_SINK_BUFFER,
 	CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM,
-- 
2.17.1

[PATCH v6 2/3] dt-bindings: arm: Add support for Coresight dummy trace

[Hao Zhang]

This patch add support for Coresight dummy source and dummy sink trace.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
---
 .../arm/arm,coresight-dummy-sink.yaml         | 73 +++++++++++++++++++
 .../arm/arm,coresight-dummy-source.yaml       | 71 ++++++++++++++++++
 2 files changed, 144 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
 create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml

diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
new file mode 100644
index 000000000000..cb78cfa56702
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-sink.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Coresight Dummy sink component
+
+description: |
+  CoreSight components are compliant with the ARM CoreSight architecture
+  specification and can be connected in various topologies to suit a particular
+  SoCs tracing needs. These trace components can generally be classified as
+  sinks, links and sources. Trace data produced by one or more sources flows
+  through the intermediate links connecting the source to the currently selected
+  sink.
+
+  The Coresight dummy sink component is for the specific coresight sink devices
+  kernel don't have permission to access or configure, e.g., CoreSight EUD on
+  Qualcomm platforms. It is a mini-USB hub implemented to support the USB-based
+  debug and trace capabilities. For this device, a dummy driver is needed to
+  register it as Coresight sink device in kernel side, so that path can be
+  created in the driver. Then the trace flow would be transferred to EUD via
+  coresight link of AP processor. It provides Coresight API for operations on
+  dummy source devices, such as enabling and disabling them. It also provides
+  the Coresight dummy source paths for debugging.
+
+  The primary use case of the coresight dummy sink is to build path in kernel
+  side for dummy sink component.
+
+maintainers:
+  - Mike Leach <mike.leach@linaro.org>
+  - Suzuki K Poulose <suzuki.poulose@arm.com>
+  - James Clark <james.clark@arm.com>
+  - Mao Jinlong <quic_jinlmao@quicinc.com>
+  - Hao Zhang <quic_hazha@quicinc.com>
+
+properties:
+  compatible:
+    enum:
+      - arm,coresight-dummy-sink
+
+  in-ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port:
+        description: Input connection from the Coresight Trace bus to
+          dummy sink, such as Embedded USB debugger(EUD).
+
+        $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - in-ports
+
+additionalProperties: false
+
+examples:
+  # Minimum dummy sink definition. Dummy sink connect to coresight replicator.
+  - |
+    sink {
+      compatible = "arm,coresight-dummy-sink";
+
+      in-ports {
+        port {
+          eud_in_replicator_swao: endpoint {
+            remote-endpoint = <&replicator_swao_out_eud>;
+          };
+        };
+      };
+    };
+
+...
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
new file mode 100644
index 000000000000..5fedaed49a1f
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-source.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Coresight Dummy source component
+
+description: |
+  CoreSight components are compliant with the ARM CoreSight architecture
+  specification and can be connected in various topologies to suit a particular
+  SoCs tracing needs. These trace components can generally be classified as
+  sinks, links and sources. Trace data produced by one or more sources flows
+  through the intermediate links connecting the source to the currently selected
+  sink.
+
+  The Coresight dummy source component is for the specific coresight source
+  devices kernel don't have permission to access or configure. For some SOCs,
+  there would be Coresight source trace components on sub-processor which
+  are conneted to AP processor via debug bus. For these devices, a dummy driver
+  is needed to register them as Coresight source devices, so that paths can be
+  created in the driver. It provides Coresight API for operations on dummy
+  source devices, such as enabling and disabling them. It also provides the
+  Coresight dummy source paths for debugging.
+
+  The primary use case of the coresight dummy source is to build path in kernel
+  side for dummy source component.
+
+maintainers:
+  - Mike Leach <mike.leach@linaro.org>
+  - Suzuki K Poulose <suzuki.poulose@arm.com>
+  - James Clark <james.clark@arm.com>
+  - Mao Jinlong <quic_jinlmao@quicinc.com>
+  - Hao Zhang <quic_hazha@quicinc.com>
+
+properties:
+  compatible:
+    enum:
+      - arm,coresight-dummy-source
+
+  out-ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port:
+        description: Output connection from the source to Coresight
+          Trace bus.
+        $ref: /schemas/graph.yaml#/properties/port
+
+required:
+  - compatible
+  - out-ports
+
+additionalProperties: false
+
+examples:
+  # Minimum dummy source definition. Dummy source connect to coresight funnel.
+  - |
+    source {
+      compatible = "arm,coresight-dummy-source";
+
+      out-ports {
+        port {
+          dummy_riscv_out_funnel_swao: endpoint {
+            remote-endpoint = <&funnel_swao_in_dummy_riscv>;
+          };
+        };
+      };
+    };
+
+...
-- 
2.17.1

[PATCH v6 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace

[Hao Zhang]

Add documentation for Coresight Dummy Trace under trace/coresight.

Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
---
 .../trace/coresight/coresight-dummy.rst       | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 Documentation/trace/coresight/coresight-dummy.rst

diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst
new file mode 100644
index 000000000000..eff7c553ee6c
--- /dev/null
+++ b/Documentation/trace/coresight/coresight-dummy.rst
@@ -0,0 +1,32 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============================
+Coresight Dummy Trace Module
+=============================
+
+    :Author:   Hao Zhang <quic_hazha@quicinc.com>
+    :Date:     June 2023
+
+Introduction
+------------
+
+The Coresight dummy trace module is for the specific devices that kernel don't
+have permission to access or configure, e.g., CoreSight TPDMs on Qualcomm
+platforms. For these devices, a dummy driver is needed to register them as
+Coresight devices. The module may also be used to define components that may
+not have any programming interfaces, so that paths can be created in the driver.
+It provides Coresight API for operations on dummy devices, such as enabling and
+disabling them. It also provides the Coresight dummy sink/source paths for
+debugging.
+
+Config details
+--------------
+
+There are two types of nodes, dummy sink and dummy source. These nodes
+are available at ``/sys/bus/coresight/devices``.
+
+Example output::
+
+    $ ls -l /sys/bus/coresight/devices | grep dummy
+    dummy_sink0 -> ../../../devices/platform/soc@0/soc@0:sink/dummy_sink0
+    dummy_source0 -> ../../../devices/platform/soc@0/soc@0:source/dummy_source0
-- 
2.17.1

Re: [PATCH v6 1/3] Coresight: Add coresight dummy driver

[Hao Zhang]

Hi Reviewers,

Could you please help to review this patch?

Thanks
Hao

On 6/2/2023 4:41 PM, Hao Zhang wrote:
> Some Coresight devices that kernel don't have permission to access or
> configure. For these devices, a dummy driver is needed to register them as
> Coresight devices. The module may also be used to define components that
> may not have any programming interfaces, so that paths can be created
> in the driver. It provides Coresight API for operations on dummy devices,
> such as enabling and disabling them. It also provides the Coresight dummy
> sink/source paths for debugging.
> 
> Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
> ---
>   drivers/hwtracing/coresight/Kconfig           |  11 ++
>   drivers/hwtracing/coresight/Makefile          |   1 +
>   drivers/hwtracing/coresight/coresight-dummy.c | 163 ++++++++++++++++++
>   include/linux/coresight.h                     |   1 +
>   4 files changed, 176 insertions(+)
>   create mode 100644 drivers/hwtracing/coresight/coresight-dummy.c
> 
> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> index 2b5bbfffbc4f..06f0a7594169 100644
> --- a/drivers/hwtracing/coresight/Kconfig
> +++ b/drivers/hwtracing/coresight/Kconfig
> @@ -236,4 +236,15 @@ config CORESIGHT_TPDA
>   
>   	  To compile this driver as a module, choose M here: the module will be
>   	  called coresight-tpda.
> +
> +config CORESIGHT_DUMMY
> +	tristate "Dummy driver support"
> +	help
> +	  Enables support for dummy driver. Dummy driver can be used for
> +	  CoreSight sources/sinks that are owned and configured by some
> +	  other subsystem and use Linux drivers to configure rest of trace
> +	  path.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called coresight-dummy.
>   endif
> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
> index 33bcc3f7b8ae..995d3b2c76df 100644
> --- a/drivers/hwtracing/coresight/Makefile
> +++ b/drivers/hwtracing/coresight/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
>   coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
>   		   coresight-cti-sysfs.o
>   obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o
> +obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
> diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c
> new file mode 100644
> index 000000000000..42125b7a0f39
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-dummy.c
> @@ -0,0 +1,163 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/coresight.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "coresight-priv.h"
> +
> +struct dummy_drvdata {
> +	struct device			*dev;
> +	struct coresight_device		*csdev;
> +};
> +
> +DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
> +DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");
> +
> +static int dummy_source_enable(struct coresight_device *csdev,
> +			       struct perf_event *event, u32 mode)
> +{
> +	dev_dbg(csdev->dev.parent, "Dummy source enabled\n");
> +
> +	return 0;
> +}
> +
> +static void dummy_source_disable(struct coresight_device *csdev,
> +				 struct perf_event *event)
> +{
> +	dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
> +}
> +
> +static int dummy_sink_enable(struct coresight_device *csdev, u32 mode,
> +				void *data)
> +{
> +	dev_dbg(csdev->dev.parent, "Dummy sink enabled\n");
> +
> +	return 0;
> +}
> +
> +static int dummy_sink_disable(struct coresight_device *csdev)
> +{
> +	dev_dbg(csdev->dev.parent, "Dummy sink disabled\n");
> +
> +	return 0;
> +}
> +
> +static const struct coresight_ops_source dummy_source_ops = {
> +	.enable	= dummy_source_enable,
> +	.disable = dummy_source_disable,
> +};
> +
> +static const struct coresight_ops dummy_source_cs_ops = {
> +	.source_ops = &dummy_source_ops,
> +};
> +
> +static const struct coresight_ops_sink dummy_sink_ops = {
> +	.enable	= dummy_sink_enable,
> +	.disable = dummy_sink_disable,
> +};
> +
> +static const struct coresight_ops dummy_sink_cs_ops = {
> +	.sink_ops = &dummy_sink_ops,
> +};
> +
> +static int dummy_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	struct coresight_platform_data *pdata;
> +	struct dummy_drvdata *drvdata;
> +	struct coresight_desc desc = { 0 };
> +
> +	if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
> +
> +		desc.name = coresight_alloc_device_name(&source_devs, dev);
> +		if (!desc.name)
> +			return -ENOMEM;
> +
> +		desc.type = CORESIGHT_DEV_TYPE_SOURCE;
> +		desc.subtype.source_subtype =
> +					CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
> +		desc.ops = &dummy_source_cs_ops;
> +	} else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) {
> +		desc.name = coresight_alloc_device_name(&sink_devs, dev);
> +		if (!desc.name)
> +			return -ENOMEM;
> +
> +		desc.type = CORESIGHT_DEV_TYPE_SINK;
> +		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_DUMMY;
> +		desc.ops = &dummy_sink_cs_ops;
> +	} else {
> +		dev_err(dev, "Device type not set\n");
> +		return -EINVAL;
> +	}
> +
> +	pdata = coresight_get_platform_data(dev);
> +	if (IS_ERR(pdata))
> +		return PTR_ERR(pdata);
> +	pdev->dev.platform_data = pdata;
> +
> +	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata)
> +		return -ENOMEM;
> +
> +	drvdata->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, drvdata);
> +
> +	desc.pdata = pdev->dev.platform_data;
> +	desc.dev = &pdev->dev;
> +	drvdata->csdev = coresight_register(&desc);
> +	if (IS_ERR(drvdata->csdev))
> +		return PTR_ERR(drvdata->csdev);
> +
> +	pm_runtime_enable(dev);
> +	dev_dbg(dev, "Dummy device initialized\n");
> +
> +	return 0;
> +}
> +
> +static int dummy_remove(struct platform_device *pdev)
> +{
> +	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +
> +	pm_runtime_disable(dev);
> +	coresight_unregister(drvdata->csdev);
> +	return 0;
> +}
> +
> +static const struct of_device_id dummy_match[] = {
> +	{.compatible = "arm,coresight-dummy-source"},
> +	{.compatible = "arm,coresight-dummy-sink"},
> +	{},
> +};
> +
> +static struct platform_driver dummy_driver = {
> +	.probe	= dummy_probe,
> +	.remove	= dummy_remove,
> +	.driver	= {
> +		.name   = "coresight-dummy",
> +		.of_match_table = dummy_match,
> +	},
> +};
> +
> +static int __init dummy_init(void)
> +{
> +	return platform_driver_register(&dummy_driver);
> +}
> +module_init(dummy_init);
> +
> +static void __exit dummy_exit(void)
> +{
> +	platform_driver_unregister(&dummy_driver);
> +}
> +module_exit(dummy_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("CoreSight dummy driver");
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index f19a47b9bb5a..6db4b49751cf 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -45,6 +45,7 @@ enum coresight_dev_type {
>   };
>   
>   enum coresight_dev_subtype_sink {
> +	CORESIGHT_DEV_SUBTYPE_SINK_DUMMY,
>   	CORESIGHT_DEV_SUBTYPE_SINK_PORT,
>   	CORESIGHT_DEV_SUBTYPE_SINK_BUFFER,
>   	CORESIGHT_DEV_SUBTYPE_SINK_SYSMEM,

Re: [PATCH v6 2/3] dt-bindings: arm: Add support for Coresight dummy trace

[Hao Zhang]

Hi Reviewers,

Could you please help to review this patch?

Thanks
Hao

On 6/2/2023 4:41 PM, Hao Zhang wrote:
> This patch add support for Coresight dummy source and dummy sink trace.
> 
> Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
> ---
>   .../arm/arm,coresight-dummy-sink.yaml         | 73 +++++++++++++++++++
>   .../arm/arm,coresight-dummy-source.yaml       | 71 ++++++++++++++++++
>   2 files changed, 144 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
>   create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
> new file mode 100644
> index 000000000000..cb78cfa56702
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
> @@ -0,0 +1,73 @@
> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-sink.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ARM Coresight Dummy sink component
> +
> +description: |
> +  CoreSight components are compliant with the ARM CoreSight architecture
> +  specification and can be connected in various topologies to suit a particular
> +  SoCs tracing needs. These trace components can generally be classified as
> +  sinks, links and sources. Trace data produced by one or more sources flows
> +  through the intermediate links connecting the source to the currently selected
> +  sink.
> +
> +  The Coresight dummy sink component is for the specific coresight sink devices
> +  kernel don't have permission to access or configure, e.g., CoreSight EUD on
> +  Qualcomm platforms. It is a mini-USB hub implemented to support the USB-based
> +  debug and trace capabilities. For this device, a dummy driver is needed to
> +  register it as Coresight sink device in kernel side, so that path can be
> +  created in the driver. Then the trace flow would be transferred to EUD via
> +  coresight link of AP processor. It provides Coresight API for operations on
> +  dummy source devices, such as enabling and disabling them. It also provides
> +  the Coresight dummy source paths for debugging.
> +
> +  The primary use case of the coresight dummy sink is to build path in kernel
> +  side for dummy sink component.
> +
> +maintainers:
> +  - Mike Leach <mike.leach@linaro.org>
> +  - Suzuki K Poulose <suzuki.poulose@arm.com>
> +  - James Clark <james.clark@arm.com>
> +  - Mao Jinlong <quic_jinlmao@quicinc.com>
> +  - Hao Zhang <quic_hazha@quicinc.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - arm,coresight-dummy-sink
> +
> +  in-ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port:
> +        description: Input connection from the Coresight Trace bus to
> +          dummy sink, such as Embedded USB debugger(EUD).
> +
> +        $ref: /schemas/graph.yaml#/properties/port
> +
> +required:
> +  - compatible
> +  - in-ports
> +
> +additionalProperties: false
> +
> +examples:
> +  # Minimum dummy sink definition. Dummy sink connect to coresight replicator.
> +  - |
> +    sink {
> +      compatible = "arm,coresight-dummy-sink";
> +
> +      in-ports {
> +        port {
> +          eud_in_replicator_swao: endpoint {
> +            remote-endpoint = <&replicator_swao_out_eud>;
> +          };
> +        };
> +      };
> +    };
> +
> +...
> diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
> new file mode 100644
> index 000000000000..5fedaed49a1f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
> @@ -0,0 +1,71 @@
> +# SPDX-License-Identifier: GPL-2.0-only or BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/arm,coresight-dummy-source.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ARM Coresight Dummy source component
> +
> +description: |
> +  CoreSight components are compliant with the ARM CoreSight architecture
> +  specification and can be connected in various topologies to suit a particular
> +  SoCs tracing needs. These trace components can generally be classified as
> +  sinks, links and sources. Trace data produced by one or more sources flows
> +  through the intermediate links connecting the source to the currently selected
> +  sink.
> +
> +  The Coresight dummy source component is for the specific coresight source
> +  devices kernel don't have permission to access or configure. For some SOCs,
> +  there would be Coresight source trace components on sub-processor which
> +  are conneted to AP processor via debug bus. For these devices, a dummy driver
> +  is needed to register them as Coresight source devices, so that paths can be
> +  created in the driver. It provides Coresight API for operations on dummy
> +  source devices, such as enabling and disabling them. It also provides the
> +  Coresight dummy source paths for debugging.
> +
> +  The primary use case of the coresight dummy source is to build path in kernel
> +  side for dummy source component.
> +
> +maintainers:
> +  - Mike Leach <mike.leach@linaro.org>
> +  - Suzuki K Poulose <suzuki.poulose@arm.com>
> +  - James Clark <james.clark@arm.com>
> +  - Mao Jinlong <quic_jinlmao@quicinc.com>
> +  - Hao Zhang <quic_hazha@quicinc.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - arm,coresight-dummy-source
> +
> +  out-ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port:
> +        description: Output connection from the source to Coresight
> +          Trace bus.
> +        $ref: /schemas/graph.yaml#/properties/port
> +
> +required:
> +  - compatible
> +  - out-ports
> +
> +additionalProperties: false
> +
> +examples:
> +  # Minimum dummy source definition. Dummy source connect to coresight funnel.
> +  - |
> +    source {
> +      compatible = "arm,coresight-dummy-source";
> +
> +      out-ports {
> +        port {
> +          dummy_riscv_out_funnel_swao: endpoint {
> +            remote-endpoint = <&funnel_swao_in_dummy_riscv>;
> +          };
> +        };
> +      };
> +    };
> +
> +...

Re: [PATCH v6 2/3] dt-bindings: arm: Add support for Coresight dummy trace

[Rob Herring]

On Fri, 02 Jun 2023 16:41:48 +0800, Hao Zhang wrote:
> This patch add support for Coresight dummy source and dummy sink trace.
> 
> Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
> ---
>  .../arm/arm,coresight-dummy-sink.yaml         | 73 +++++++++++++++++++
>  .../arm/arm,coresight-dummy-source.yaml       | 71 ++++++++++++++++++
>  2 files changed, 144 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-sink.yaml
>  create mode 100644 Documentation/devicetree/bindings/arm/arm,coresight-dummy-source.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v6 0/3] Add support to configure Coresight Dummy subunit

[Suzuki K Poulose]

On Fri, 2 Jun 2023 16:41:46 +0800, Hao Zhang wrote:
> Introduction of Coresight Dummy subunit
> The Coresight Dummy subunit is for Coresight Dummy component, there are
> some specific Coresight devices that HLOS don't have permission to access.
> Such as some TPDMs, they would be configured in NON-HLOS side, but it's
> necessary to build Coresight path for it to debug. So there need driver to
> register dummy devices as Coresight devices.
> 
> [...]

Applied, thanks!

[1/3] Coresight: Add coresight dummy driver
      commit: 9d3ba0b6c056918355cf36094d6ed63cdd01a2ab
[2/3] dt-bindings: arm: Add support for Coresight dummy trace
      commit: 5911ff4559e45532c1f67257c5731b5e13f5e7a3
[3/3] Documentation: trace: Add documentation for Coresight Dummy Trace
      commit: 3b79104f80036231a40ba5d15c3e329985029a0f

Best regards,
-- 
Suzuki K Poulose <suzuki.poulose@arm.com>