[PATCH v6 0/5] coresight: Add remote etm support

[PATCH v6 0/5] coresight: Add remote etm support

[Mao Jinlong]

The system on chip (SoC) consists of main APSS(Applications processor
subsytem) and additional processors like modem, lpass. There is
coresight-etm driver for etm trace of APSS. Coresight remote etm driver
is for enabling and disabling the etm trace of remote processors.
It uses QMI interface to communicate with remote processors' software
and uses coresight framework to configure the connection from remote
etm source to TMC sinks.

Example to capture the remote etm trace:

Enable source:
echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
echo 1 > /sys/bus/coresight/devices/remote_etm0/enable_source

Capture the trace:
cat /dev/tmc_etf0 > /data/remote_etm.bin

Disable source:
echo 0 > /sys/bus/coresight/devices/remote_etm0/enable_source

Changes since V5:
1. Fix the warning and error when compile.
2. Add traceid for remote etm.
3. Change qcom,qmi-id tp qcom,qmi-instance-id.

Changes since V4:
1. Add coresight QMI driver
2. Add coresight qmi node and qcom,qmi-id of modem-etm in msm8996 dtsi
V5: https://lwn.net/ml/all/20250424115854.2328190-1-quic_jinlmao@quicinc.com/

Changes since V3:
1. Use different compatible for different remote etms in dt.
2. Get qmi instance id from the match table data in driver.

Change since V2:
1. Change qcom,inst-id to qcom,qmi-id
2. Fix the error in code for type of remote_etm_remove
3. Depend on QMI helper in Kconfig

Changes since V1:
1. Remove unused content
2. Use CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS as remote etm source type.
3. Use enabled instead of enable in driver data.
4. Validate instance id value where it's read from the DT.

Mao Jinlong (5):
  dt-bindings: arm: Add CoreSight QMI component description
  coresight: Add coresight QMI driver
  dt-bindings: arm: Add qcom,qmi-id for remote etm
  coresight: Add remote etm support
  arm64: dts: qcom: msm8996: Add coresight qmi node

 .../bindings/arm/qcom,coresight-qmi.yaml      |  65 +++++
 .../arm/qcom,coresight-remote-etm.yaml        |   9 +
 arch/arm64/boot/dts/qcom/msm8996.dtsi         |  11 +
 drivers/hwtracing/coresight/Kconfig           |  23 ++
 drivers/hwtracing/coresight/Makefile          |   2 +
 drivers/hwtracing/coresight/coresight-qmi.c   | 198 +++++++++++++
 drivers/hwtracing/coresight/coresight-qmi.h   | 101 +++++++
 .../coresight/coresight-remote-etm.c          | 262 ++++++++++++++++++
 8 files changed, 671 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.c
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h
 create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c

-- 
2.25.1

[PATCH v6 1/5] dt-bindings: arm: Add CoreSight QMI component description

[Mao Jinlong]

Add new coresight-qmi.yaml file describing the bindings required
to define qmi node in the device trees.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 .../bindings/arm/qcom,coresight-qmi.yaml      | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml

diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
new file mode 100644
index 000000000000..601c865fe4d7
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/qcom,coresight-qmi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm coresight QMI(Qualcomm Messaging Interface) component
+
+description: |
+  Qualcomm Messaging Interface (QMI) is an interface that clients can
+  use to send, and receive, messages from a remote entity. The coresight
+  QMI component is to configure QMI instance ids and service ids for different
+  remote subsystem connections. Coresight QMI driver uses the ids to init
+  the qmi connections. Other coresight drivers call the send qmi request
+  function when connection is established.
+
+maintainers:
+  - Mao Jinlong <quic_jinlmao@quicinc.com>
+
+properties:
+  compatible:
+    enum:
+      - qcom,coresight-qmi
+
+patternProperties:
+  '^conns(-[0-9]+)?$':
+    type: object
+    description:
+      QMI instance id and service id for different remote subsystem connections.
+
+    properties:
+      qmi-id:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Instance id for the remote subsystem connection.
+
+      service-id:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Service id for the remote subsystem connection.
+
+    additionalProperties: false
+
+    required:
+      - qmi-id
+      - service-id
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  # Minimum coresight qmi definition.
+  - |
+    coresight-qmi {
+      compatible = "qcom,coresight-qmi";
+
+      conns-0 {
+          qmi-id = <0xd>;
+          service-id = <0x33>;
+      };
+    };
+
+...
-- 
2.25.1

[PATCH v6 2/5] coresight: Add coresight QMI driver

[Mao Jinlong]

Coresight QMI driver uses QMI(Qualcomm Messaging Interface) interfaces
to communicate with remote subsystems. Driver gets the instance id and
service id from device tree node and init the QMI connections to remote
subsystems. Send request function is for other coresight drivers to
communicate with remote subsystems.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 drivers/hwtracing/coresight/Kconfig         |  11 ++
 drivers/hwtracing/coresight/Makefile        |   1 +
 drivers/hwtracing/coresight/coresight-qmi.c | 198 ++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-qmi.h | 101 ++++++++++
 4 files changed, 311 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.c
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index f064e3d172b3..a55b7d875e0a 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -268,4 +268,15 @@ config CORESIGHT_KUNIT_TESTS
 	    Enable Coresight unit tests. Only useful for development and not
 	    intended for production.
 
+config CORESIGHT_QMI
+	tristate "CORESIGHT QMI support"
+	depends on QCOM_QMI_HELPERS
+	help
+	  Enables support for sending command to subsystem via QMI. This is
+	  primarily used for sending QMI message to subsystems for remote trace
+	  sources.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called coresight-qmi.
+
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 4e7cc3c5bf99..d4b1c74d183f 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -52,6 +52,7 @@ 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-$(CONFIG_CORESIGHT_QMI) += coresight-qmi.o
 obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
 obj-$(CONFIG_CORESIGHT_CTCU) += coresight-ctcu.o
 coresight-ctcu-y := coresight-ctcu-core.o
diff --git a/drivers/hwtracing/coresight/coresight-qmi.c b/drivers/hwtracing/coresight/coresight-qmi.c
new file mode 100644
index 000000000000..d487280d516b
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-qmi.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/coresight.h>
+
+#include "coresight-qmi.h"
+static LIST_HEAD(qmi_data);
+
+static int service_coresight_qmi_new_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct qmi_data *data = container_of(qmi,
+					struct qmi_data, handle);
+
+	data->s_addr.sq_family = AF_QIPCRTR;
+	data->s_addr.sq_node = svc->node;
+	data->s_addr.sq_port = svc->port;
+	data->service_connected = true;
+	pr_debug("Connection established between QMI handle and %d service\n",
+		data->qmi_id);
+
+	return 0;
+}
+
+static void service_coresight_qmi_del_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct qmi_data *data = container_of(qmi,
+					struct qmi_data, handle);
+	data->service_connected = false;
+	pr_debug("Connection disconnected between QMI handle and %d service\n",
+		data->qmi_id);
+}
+
+static struct qmi_ops server_ops = {
+	.new_server = service_coresight_qmi_new_server,
+	.del_server = service_coresight_qmi_del_server,
+};
+
+static int coresight_qmi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *child_node;
+	int ret;
+
+	/*
+	 * Create QMI handle and register new lookup for each
+	 * QMI connectioni based on qmi-id and service-id.
+	 */
+	for_each_available_child_of_node(node, child_node) {
+		struct qmi_data *data;
+
+		data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
+
+		ret = of_property_read_u32(child_node, "qmi-id", &data->qmi_id);
+		if (ret)
+			return ret;
+
+		ret = of_property_read_u32(child_node, "service-id", &data->service_id);
+		if (ret)
+			return ret;
+
+		ret = qmi_handle_init(&data->handle,
+				CORESIGHT_QMI_MAX_MSG_LEN,
+				&server_ops, NULL);
+		if (ret < 0) {
+			dev_err(dev, "qmi client init failed ret:%d\n", ret);
+			return ret;
+		}
+
+		qmi_add_lookup(&data->handle,
+				data->service_id,
+				CORESIGHT_QMI_VERSION,
+				data->qmi_id);
+
+		list_add(&data->node, &qmi_data);
+	}
+
+	return 0;
+}
+
+/**
+ * coresight_get_qmi_data() - Get the qmi data struct from qmi_data
+ * @id:	instance id to get the qmi data
+ *
+ * Return: qmi data struct on success, NULL on failure.
+ */
+static struct qmi_data *coresight_get_qmi_data(int id)
+{
+	struct qmi_data *data;
+
+	list_for_each_entry(data, &qmi_data, node) {
+		if (data->qmi_id == id)
+			return data;
+	}
+
+	return NULL;
+}
+
+/**
+ * coresight_send_qmi_request() - Send a QMI message to remote subsystem
+ * @instance_id:	QMI Instance id of the remote subsystem
+ * @msg_id:	message id of the request
+ * @resp_ei:	description of how to decode a matching response
+ * @req_ei:	description of how to encode a matching request
+ * @resp:	pointer to the object to decode the response info
+ * @req:	pointer to the object to encode the request info
+ * @len:	max length of the QMI message
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int coresight_send_qmi_request(int instance_id, int msg_id, struct qmi_elem_info *resp_ei,
+			struct qmi_elem_info *req_ei, void *resp, void *req, int len)
+{
+	struct qmi_txn txn;
+	int ret;
+	struct qmi_data *data;
+
+	data = coresight_get_qmi_data(instance_id);
+	if (!data) {
+		pr_err("No QMI data for QMI service!\n");
+		ret = -EINVAL;
+		return ret;
+	}
+
+	if (!data->service_connected) {
+		pr_err("QMI service not connected!\n");
+		ret = -EINVAL;
+		return ret;
+	}
+
+	ret = qmi_txn_init(&data->handle, &txn,
+			resp_ei,
+			resp);
+
+	if (ret < 0) {
+		pr_err("QMI tx init failed , ret:%d\n", ret);
+		return ret;
+	}
+
+	ret = qmi_send_request(&data->handle, &data->s_addr,
+			&txn, msg_id,
+			len,
+			req_ei,
+			req);
+
+	if (ret < 0) {
+		pr_err("QMI send ACK failed, ret:%d\n", ret);
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, msecs_to_jiffies(TIMEOUT_MS));
+	if (ret < 0) {
+		pr_err("QMI qmi txn wait failed, ret:%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(coresight_send_qmi_request);
+
+static void coresight_qmi_remove(struct platform_device *pdev)
+{
+	struct qmi_data *data;
+
+	list_for_each_entry(data, &qmi_data, node) {
+		qmi_handle_release(&data->handle);
+	}
+}
+
+static const struct of_device_id coresight_qmi_match[] = {
+	{ .compatible = "qcom,coresight-qmi" },
+	{}
+};
+
+static struct platform_driver coresight_qmi_driver = {
+	.probe          = coresight_qmi_probe,
+	.remove         = coresight_qmi_remove,
+	.driver         = {
+		.name   = "coresight-qmi",
+		.of_match_table = coresight_qmi_match,
+	},
+};
+
+module_platform_driver(coresight_qmi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight QMI driver");
diff --git a/drivers/hwtracing/coresight/coresight-qmi.h b/drivers/hwtracing/coresight/coresight-qmi.h
new file mode 100644
index 000000000000..dce10d899a53
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-qmi.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef _CORESIGHT_QMI_H
+#define _CORESIGHT_QMI_H
+
+#include <linux/soc/qcom/qmi.h>
+
+#define CORESIGHT_QMI_VERSION			1
+
+#define CORESIGHT_QMI_SET_ETM_REQ_V01		0x002C
+#define CORESIGHT_QMI_SET_ETM_RESP_V01		0x002C
+
+#define CORESIGHT_QMI_MAX_MSG_LEN 50
+
+#define TIMEOUT_MS				10000
+
+/* Qmi data for the QMI connection */
+struct qmi_data {
+	u32			qmi_id;
+	u32			service_id;
+	struct list_head	node;
+	struct qmi_handle	handle;
+	bool			service_connected;
+	struct sockaddr_qrtr	s_addr;
+};
+
+/* Enum of QMI service IDs */
+enum coresight_qmi_service_id {
+	CORESIGHT_QMI_QDSSC_SVC_ID = 0x33,
+	CORESIGHT_QMI_QDCP_SVC_ID = 0xff,
+};
+
+/* Enum of QMI instance ids */
+enum coresight_qmi_instance_id {
+	CORESIGHT_QMI_INSTANCE_MODEM_V01 = 2,
+	CORESIGHT_QMI_INSTANCE_WLAN_V01 = 3,
+	CORESIGHT_QMI_INSTANCE_AOP_V01 = 4,
+	CORESIGHT_QMI_INSTANCE_ADSP_V01 = 5,
+	CORESIGHT_QMI_INSTANCE_VENUS_V01 = 6,
+	CORESIGHT_QMI_INSTANCE_GNSS_V01 = 7,
+	CORESIGHT_QMI_INSTANCE_SENSOR_V01 = 8,
+	CORESIGHT_QMI_INSTANCE_AUDIO_V01 = 9,
+	CORESIGHT_QMI_INSTANCE_VPU_V01 = 10,
+	CORESIGHT_QMI_INSTANCE_MODEM2_V01 = 11,
+	CORESIGHT_QMI_INSTANCE_SENSOR2_V01 = 12,
+	CORESIGHT_QMI_INSTANCE_CDSP_V01 = 13,
+	CORESIGHT_QMI_INSTANCE_NPU_V01 = 14,
+	CORESIGHT_QMI_INSTANCE_CDSP_USER_V01 = 15,
+	CORESIGHT_QMI_INSTANCE_CDSP1_V01 = 16,
+	CORESIGHT_QMI_INSTANCE_GPDSP0_V01 = 17,
+	CORESIGHT_QMI_INSTANCE_GPDSP1_V01 = 18,
+	CORESIGHT_QMI_INSTANCE_TBD_V01 = 19,
+	CORESIGHT_QMI_INSTANCE_GPDSP0_AUDI0_V01 = 20,
+	CORESIGHT_QMI_INSTANCE_GPDSP1_AUDI0_V01 = 21,
+	CORESIGHT_QMI_INSTANCE_MODEM_OEM_V01 = 22,
+	CORESIGHT_QMI_INSTANCE_ADSP1_V01 = 23,
+	CORESIGHT_QMI_INSTANCE_ADSP1_AUDIO_V01 = 24,
+	CORESIGHT_QMI_INSTANCE_ADSP2_V01 = 25,
+	CORESIGHT_QMI_INSTANCE_ADSP2_AUDIO_V01 = 26,
+	CORESIGHT_QMI_INSTANCE_CDSP2_V01 = 27,
+	CORESIGHT_QMI_INSTANCE_CDSP3_V01 = 28,
+};
+
+enum coresight_etm_state_enum_type_v01 {
+	/* To force a 32 bit signed enum. Do not change or use */
+	CORESIGHT_ETM_STATE_ENUM_TYPE_MIN_ENUM_VAL_V01 = INT_MIN,
+	CORESIGHT_ETM_STATE_DISABLED_V01 = 0,
+	CORESIGHT_ETM_STATE_ENABLED_V01 = 1,
+	CORESIGHT_ETM_STATE_ENUM_TYPE_MAX_ENUM_VAL_01 = INT_MAX,
+};
+
+/**
+ * Set remote etm request message
+ *
+ * @state enable/disable state
+ */
+struct coresight_set_etm_req_msg_v01 {
+	enum coresight_etm_state_enum_type_v01 state;
+};
+
+/**
+ * Set remote etm response message
+ */
+struct coresight_set_etm_resp_msg_v01 {
+	struct qmi_response_type_v01 resp;
+};
+
+#if IS_ENABLED(CONFIG_CORESIGHT_QMI)
+extern int coresight_send_qmi_request(int instance_id, int msg_id,
+		struct qmi_elem_info *resp_ei,
+		struct qmi_elem_info *req_ei, void *resp, void *req, int len);
+#else
+
+static inline int coresight_send_qmi_request(int instance_id, int msg_id,
+		struct qmi_elem_info *resp_ei,
+		struct qmi_elem_info *req_ei, void *resp, void *req, int len) {return NULL; }
+#endif
+
+#endif
-- 
2.25.1

[PATCH v6 3/5] dt-bindings: arm: Add qcom,qmi-id for remote etm

[Mao Jinlong]

Remote etm binding change was merged to fix the dt warning. Driver
changes were not merged at that time. qcom,qmi-instance-id is
required for remote etm driver to find the remote subsystem connection.
It is the instance id used by qmi to communicate with remote processor.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 .../bindings/arm/qcom,coresight-remote-etm.yaml          | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
index 4fd5752978cd..bd78f6bc2fdf 100644
--- a/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
+++ b/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
@@ -20,6 +20,12 @@ properties:
   compatible:
     const: qcom,coresight-remote-etm
 
+  qcom,qmi-instance-id:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Each remote processor has a unique instance id to establish the
+      QMI connection.
+
   out-ports:
     $ref: /schemas/graph.yaml#/properties/ports
     additionalProperties: false
@@ -32,6 +38,7 @@ properties:
 required:
   - compatible
   - out-ports
+  - qcom,qmi-instance-id
 
 additionalProperties: false
 
@@ -40,6 +47,8 @@ examples:
     etm {
         compatible = "qcom,coresight-remote-etm";
 
+        qcom,qmi-instance-id = <2>;
+
         out-ports {
             port {
                 modem_etm0_out_funnel_modem: endpoint {
-- 
2.25.1

[PATCH v6 4/5] coresight: Add remote etm support

[Mao Jinlong]

The system on chip (SoC) consists of main APSS(Applications
processor subsytem) and additional processors like modem, lpass.
Coresight remote etm(Embedded Trace Macrocell) driver is for
enabling and disabling the etm trace of remote processors. It
uses QMI interface to communicate with remote processors' software
and uses coresight framework to configure the connection from
remote etm source to TMC sinks.

                 +-----------------+
                 |  Remote ETM     |
                 +-----------------+
                          |
                          |
                 +-----------------+
                 | Coresight Funnel|
                 +-----------------+
                          |
                          |
                 +-----------------+
                 |     TMC ETF     |
                 +-----------------+

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 drivers/hwtracing/coresight/Kconfig           |  12 +
 drivers/hwtracing/coresight/Makefile          |   1 +
 .../coresight/coresight-remote-etm.c          | 262 ++++++++++++++++++
 3 files changed, 275 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index a55b7d875e0a..0a5ab1c0a397 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -279,4 +279,16 @@ config CORESIGHT_QMI
 	  To compile this driver as a module, choose M here: the module will be
 	  called coresight-qmi.
 
+config CORESIGHT_REMOTE_ETM
+	tristate "Remote processor ETM trace support"
+	depends on QCOM_QMI_HELPERS
+	help
+	  Enables support for ETM trace collection on remote processor using
+	  CoreSight framework. Enabling this will allow turning on ETM
+	  tracing on remote processor via sysfs by configuring the required
+	  CoreSight components.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called coresight-remote-etm.
+
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index d4b1c74d183f..60bfe6ff0ecb 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -53,6 +53,7 @@ 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_QMI) += coresight-qmi.o
+obj-$(CONFIG_CORESIGHT_REMOTE_ETM) += coresight-remote-etm.o
 obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
 obj-$(CONFIG_CORESIGHT_CTCU) += coresight-ctcu.o
 coresight-ctcu-y := coresight-ctcu-core.o
diff --git a/drivers/hwtracing/coresight/coresight-remote-etm.c b/drivers/hwtracing/coresight/coresight-remote-etm.c
new file mode 100644
index 000000000000..facc1e4d057f
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-remote-etm.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/coresight.h>
+
+#include "coresight-qmi.h"
+#include "coresight-trace-id.h"
+
+#define CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN	7
+
+DEFINE_CORESIGHT_DEVLIST(remote_etm_devs, "remote-etm");
+
+/**
+ * struct remote_etm_drvdata - specifics associated to remote etm device
+ * @dev:	the device entity associated to this component
+ * @csdev:	component vitals needed by the framework
+ * @mutex:	lock for seting etm
+ * @inst_id:	the instance id of the remote connection
+ * @traceid:	value of the current trace ID for this component.
+ */
+struct remote_etm_drvdata {
+	struct device			*dev;
+	struct coresight_device		*csdev;
+	struct mutex			mutex;
+	u32				inst_id;
+	u8				traceid;
+};
+
+/*
+ * Element info to descrbe the coresight_set_etm_req_msg_v01 struct
+ * which is used to encode the request.
+ */
+static struct qmi_elem_info coresight_set_etm_req_msg_v01_ei[] = {
+	{
+		.data_type = QMI_UNSIGNED_4_BYTE,
+		.elem_len  = 1,
+		.elem_size = sizeof(enum coresight_etm_state_enum_type_v01),
+		.array_type  = NO_ARRAY,
+		.tlv_type  = 0x01,
+		.offset    = offsetof(struct coresight_set_etm_req_msg_v01,
+							state),
+		.ei_array  = NULL,
+	},
+	{
+		.data_type = QMI_EOTI,
+		.elem_len  = 0,
+		.elem_size = 0,
+		.array_type  = NO_ARRAY,
+		.tlv_type  = 0,
+		.offset    = 0,
+		.ei_array  = NULL,
+	},
+};
+
+/*
+ * Element info to describe the coresight_set_etm_resp_msg_v01 struct
+ * which is used to decode the response.
+ */
+static struct qmi_elem_info coresight_set_etm_resp_msg_v01_ei[] = {
+	{
+		.data_type = QMI_STRUCT,
+		.elem_len  = 1,
+		.elem_size = sizeof(struct qmi_response_type_v01),
+		.array_type  = NO_ARRAY,
+		.tlv_type  = 0x02,
+		.offset    = offsetof(struct coresight_set_etm_resp_msg_v01,
+							resp),
+		.ei_array  = qmi_response_type_v01_ei,
+	},
+	{
+		.data_type = QMI_EOTI,
+		.elem_len  = 0,
+		.elem_size = 0,
+		.array_type  = NO_ARRAY,
+		.tlv_type  = 0,
+		.offset    = 0,
+		.ei_array  = NULL,
+	},
+};
+
+static int remote_etm_enable(struct coresight_device *csdev, struct perf_event *event,
+		enum cs_mode mode,
+		__maybe_unused struct coresight_path *path)
+{
+	struct remote_etm_drvdata *drvdata =
+		dev_get_drvdata(csdev->dev.parent);
+	struct coresight_set_etm_req_msg_v01 req;
+	struct coresight_set_etm_resp_msg_v01 resp = { { 0, 0 } };
+	int ret = 0;
+
+	mutex_lock(&drvdata->mutex);
+
+	if (mode != CS_MODE_SYSFS) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	if (!coresight_take_mode(csdev, mode)) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	req.state = CORESIGHT_ETM_STATE_ENABLED_V01;
+
+	ret = coresight_send_qmi_request(drvdata->inst_id, CORESIGHT_QMI_SET_ETM_REQ_V01,
+		coresight_set_etm_resp_msg_v01_ei,
+		coresight_set_etm_req_msg_v01_ei,
+		&resp, &req, CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN);
+
+	if (ret)
+		goto err;
+
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
+		dev_err(drvdata->dev, "QMI request failed 0x%x\n", resp.resp.error);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	mutex_unlock(&drvdata->mutex);
+	return 0;
+err:
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
+	mutex_unlock(&drvdata->mutex);
+	return ret;
+
+}
+
+static void remote_etm_disable(struct coresight_device *csdev,
+			       struct perf_event *event)
+{
+	struct remote_etm_drvdata *drvdata =
+		 dev_get_drvdata(csdev->dev.parent);
+	struct coresight_set_etm_req_msg_v01 req;
+	struct coresight_set_etm_resp_msg_v01 resp = { { 0, 0 } };
+	int ret = 0;
+
+	mutex_lock(&drvdata->mutex);
+
+	req.state = CORESIGHT_ETM_STATE_DISABLED_V01;
+
+	ret = coresight_send_qmi_request(drvdata->inst_id, CORESIGHT_QMI_SET_ETM_REQ_V01,
+					coresight_set_etm_resp_msg_v01_ei,
+					coresight_set_etm_req_msg_v01_ei,
+					&resp, &req, CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN);
+	if (ret)
+		dev_err(drvdata->dev, "Send qmi request failed %d\n", ret);
+
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01)
+		dev_err(drvdata->dev, "QMI request failed %d\n", resp.resp.error);
+
+	coresight_trace_id_put_system_id(drvdata->traceid);
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
+	mutex_unlock(&drvdata->mutex);
+}
+
+static int remote_etm_trace_id(struct coresight_device *csdev,
+			__maybe_unused enum cs_mode mode,
+			__maybe_unused struct coresight_device *sink)
+{
+	int trace_id;
+	struct remote_etm_drvdata *drvdata;
+
+	drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	trace_id = coresight_trace_id_get_system_id();
+	drvdata->traceid = (u8)trace_id;
+
+	return drvdata->traceid;
+}
+
+static const struct coresight_ops_source remote_etm_source_ops = {
+	.enable		= remote_etm_enable,
+	.disable	= remote_etm_disable,
+};
+
+static const struct coresight_ops remote_cs_ops = {
+	.source_ops	= &remote_etm_source_ops,
+	.trace_id       = remote_etm_trace_id,
+};
+
+static int remote_etm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct coresight_platform_data *pdata;
+	struct remote_etm_drvdata *drvdata;
+	struct coresight_desc desc = {0 };
+	int ret;
+
+	desc.name = coresight_alloc_device_name(&remote_etm_devs, dev);
+	if (!desc.name)
+		return -ENOMEM;
+	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 = dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	ret = of_property_read_u32(dev->of_node, "qcom,qmi-instance-id",
+			&drvdata->inst_id);
+	if (ret)
+		return ret;
+
+	mutex_init(&drvdata->mutex);
+
+	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
+	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
+	desc.ops = &remote_cs_ops;
+	desc.pdata = pdev->dev.platform_data;
+	desc.dev = &pdev->dev;
+	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto err;
+	}
+
+	dev_dbg(dev, "Remote ETM initialized\n");
+
+	return 0;
+
+err:
+	return ret;
+}
+
+static void remote_etm_remove(struct platform_device *pdev)
+{
+	struct remote_etm_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	coresight_unregister(drvdata->csdev);
+}
+
+static const struct of_device_id remote_etm_match[] = {
+	{.compatible = "qcom,coresight-remote-etm"},
+	{}
+};
+
+static struct platform_driver remote_etm_driver = {
+	.probe          = remote_etm_probe,
+	.remove         = remote_etm_remove,
+	.driver         = {
+		.name   = "coresight-remote-etm",
+		.of_match_table = remote_etm_match,
+	},
+};
+
+module_platform_driver(remote_etm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight Remote ETM driver");
-- 
2.25.1

[PATCH v6 5/5] arm64: dts: qcom: msm8996: Add coresight qmi node

[Mao Jinlong]

coresight qmi nodes is to init the qmi connection to remote subsystem.
qcom,qmi-id is used by remote etm driver to get the remote subsystem
connection and send the request.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 arch/arm64/boot/dts/qcom/msm8996.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/msm8996.dtsi b/arch/arm64/boot/dts/qcom/msm8996.dtsi
index ede851fbf628..0032817825f2 100644
--- a/arch/arm64/boot/dts/qcom/msm8996.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8996.dtsi
@@ -40,6 +40,15 @@ sleep_clk: sleep-clk {
 		};
 	};
 
+	coresight-qmi {
+		compatible = "qcom,coresight-qmi";
+
+		conns-0 {
+			qmi-id = <0x2>;
+			service-id = <0x33>;
+		};
+	};
+
 	cpus {
 		#address-cells = <2>;
 		#size-cells = <0>;
@@ -448,6 +457,8 @@ memory@80000000 {
 	etm {
 		compatible = "qcom,coresight-remote-etm";
 
+		qcom,qmi-instance-id = <0x2>;
+
 		out-ports {
 			port {
 				modem_etm_out_funnel_in2: endpoint {
-- 
2.25.1

Re: [PATCH v6 0/5] coresight: Add remote etm support

[Mike Leach]

Hi,

The majority of this code should not be in the coresight drivers
directory as it is not actually coresight.

This seems to be a communications bus system for various SoC
components - one of which happens to be a remote etm. It really needs
to be in a qcom-qmi subdirectory - which would also remove your
reliance on the coresight maintainers for getting all the qmi drivers
upstreamed. I note that there is a CONFIG dependency of
QCOM_QMI_HELPERS, which implies there is already a set of QMI
functionality not in the coresight directory.

We already have  a dummy coresight driver to cover these cases where
the actual etm source or sink might be in a different subsystem. This
could be extended in a generic manner to have an associated driver /
component, with the dummy source then forwarding the enable / disable
commands and acting as the coresight device for the purposes of
enabling the trace path from source to sink.

Thus the "coresight-remote-etm" driver becomes "qmi-node-etm" driver,
with the proprietary comms info, instance IDs etc encapsulated away
from any generic coresight information, and has an associated
coresight-dummy-source to handle the connection to the coresight trace
framework. I imagine the association could easily be modeled in device
tree using a phandle reference.

This would not change your usage model, but would give better
separation between what is clearly the QMI comms subsystem, and what
is needed to handle coresight connectivity.

Moreover, having the generic coresight dummy driver extended in this
way would allow other underlying communication systems to be used on
other devices in future.

Best Regards

Mike


On Fri, 11 Jul 2025 at 10:40, Mao Jinlong <quic_jinlmao@quicinc.com> wrote:
>
> The system on chip (SoC) consists of main APSS(Applications processor
> subsytem) and additional processors like modem, lpass. There is
> coresight-etm driver for etm trace of APSS. Coresight remote etm driver
> is for enabling and disabling the etm trace of remote processors.
> It uses QMI interface to communicate with remote processors' software
> and uses coresight framework to configure the connection from remote
> etm source to TMC sinks.
>
> Example to capture the remote etm trace:
>
> Enable source:
> echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink
> echo 1 > /sys/bus/coresight/devices/remote_etm0/enable_source
>
> Capture the trace:
> cat /dev/tmc_etf0 > /data/remote_etm.bin
>
> Disable source:
> echo 0 > /sys/bus/coresight/devices/remote_etm0/enable_source
>
> Changes since V5:
> 1. Fix the warning and error when compile.
> 2. Add traceid for remote etm.
> 3. Change qcom,qmi-id tp qcom,qmi-instance-id.
>
> Changes since V4:
> 1. Add coresight QMI driver
> 2. Add coresight qmi node and qcom,qmi-id of modem-etm in msm8996 dtsi
> V5: https://lwn.net/ml/all/20250424115854.2328190-1-quic_jinlmao@quicinc.com/
>
> Changes since V3:
> 1. Use different compatible for different remote etms in dt.
> 2. Get qmi instance id from the match table data in driver.
>
> Change since V2:
> 1. Change qcom,inst-id to qcom,qmi-id
> 2. Fix the error in code for type of remote_etm_remove
> 3. Depend on QMI helper in Kconfig
>
> Changes since V1:
> 1. Remove unused content
> 2. Use CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS as remote etm source type.
> 3. Use enabled instead of enable in driver data.
> 4. Validate instance id value where it's read from the DT.
>
> Mao Jinlong (5):
>   dt-bindings: arm: Add CoreSight QMI component description
>   coresight: Add coresight QMI driver
>   dt-bindings: arm: Add qcom,qmi-id for remote etm
>   coresight: Add remote etm support
>   arm64: dts: qcom: msm8996: Add coresight qmi node
>
>  .../bindings/arm/qcom,coresight-qmi.yaml      |  65 +++++
>  .../arm/qcom,coresight-remote-etm.yaml        |   9 +
>  arch/arm64/boot/dts/qcom/msm8996.dtsi         |  11 +
>  drivers/hwtracing/coresight/Kconfig           |  23 ++
>  drivers/hwtracing/coresight/Makefile          |   2 +
>  drivers/hwtracing/coresight/coresight-qmi.c   | 198 +++++++++++++
>  drivers/hwtracing/coresight/coresight-qmi.h   | 101 +++++++
>  .../coresight/coresight-remote-etm.c          | 262 ++++++++++++++++++
>  8 files changed, 671 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
>  create mode 100644 drivers/hwtracing/coresight/coresight-qmi.c
>  create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h
>  create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c
>
> --
> 2.25.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK

Re: [PATCH v6 1/5] dt-bindings: arm: Add CoreSight QMI component description

[Krzysztof Kozlowski]

On Fri, Jul 11, 2025 at 02:40:27AM -0700, Mao Jinlong wrote:
> Add new coresight-qmi.yaml file describing the bindings required
> to define qmi node in the device trees.
> 
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
> ---
>  .../bindings/arm/qcom,coresight-qmi.yaml      | 65 +++++++++++++++++++
>  1 file changed, 65 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
> new file mode 100644
> index 000000000000..601c865fe4d7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-qmi.yaml
> @@ -0,0 +1,65 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/qcom,coresight-qmi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm coresight QMI(Qualcomm Messaging Interface) component
> +
> +description: |
> +  Qualcomm Messaging Interface (QMI) is an interface that clients can
> +  use to send, and receive, messages from a remote entity. The coresight
> +  QMI component is to configure QMI instance ids and service ids for different
> +  remote subsystem connections. Coresight QMI driver uses the ids to init

So driver... Driver stuff is not accepted in the bindings.

> +  the qmi connections. Other coresight drivers call the send qmi request
> +  function when connection is established.
> +
> +maintainers:
> +  - Mao Jinlong <quic_jinlmao@quicinc.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,coresight-qmi

Don't send new versions while discussion is still going.

There is no need for this binding at all, it is not a coresight device.

> +
> +patternProperties:
> +  '^conns(-[0-9]+)?$':

Drop, why do you keep enforcing the node names? Look at other bindings.


Best regards,
Krzysztof

Re: [PATCH v6 3/5] dt-bindings: arm: Add qcom,qmi-id for remote etm

[Krzysztof Kozlowski]

On Fri, Jul 11, 2025 at 02:40:29AM -0700, Mao Jinlong wrote:
> Remote etm binding change was merged to fix the dt warning. Driver
> changes were not merged at that time. qcom,qmi-instance-id is
> required for remote etm driver to find the remote subsystem connection.

Again, driver... 


> It is the instance id used by qmi to communicate with remote processor.
> 
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
> ---
>  .../bindings/arm/qcom,coresight-remote-etm.yaml          | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml b/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
> index 4fd5752978cd..bd78f6bc2fdf 100644
> --- a/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
> +++ b/Documentation/devicetree/bindings/arm/qcom,coresight-remote-etm.yaml
> @@ -20,6 +20,12 @@ properties:
>    compatible:
>      const: qcom,coresight-remote-etm
>  
> +  qcom,qmi-instance-id:

Don't come with another, 20th property for your remote proc
architecture. Use existing properties.

This pattern in qcom is extremely confusing - similar thing for remote
proc called 20 different ways, just because in downstream you have 20
different drivers.

NAK

Come with unified schema for existing and future properties like that.
Assuming this is NOT FOR DRIVER in the first place.

Best regards,
Krzysztof