diff mbox series

[v2,2/2] coresight: Add remote etm support

Message ID 20240807071054.12742-3-quic_jinlmao@quicinc.com (mailing list archive)
State Superseded
Headers show
Series coresight: Add remote etm support | expand

Commit Message

Mao Jinlong Aug. 7, 2024, 7:10 a.m. UTC
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.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 drivers/hwtracing/coresight/Kconfig           |  13 +
 drivers/hwtracing/coresight/Makefile          |   1 +
 drivers/hwtracing/coresight/coresight-qmi.h   |  89 +++++
 .../coresight/coresight-remote-etm.c          | 308 ++++++++++++++++++
 4 files changed, 411 insertions(+)
 create mode 100644 drivers/hwtracing/coresight/coresight-qmi.h
 create mode 100644 drivers/hwtracing/coresight/coresight-remote-etm.c

Comments

kernel test robot Aug. 7, 2024, 9:27 p.m. UTC | #1
Hi Mao,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.11-rc2 next-20240807]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mao-Jinlong/dt-bindings-arm-Add-qcom-inst-id-for-remote-etm/20240807-151315
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20240807071054.12742-3-quic_jinlmao%40quicinc.com
patch subject: [PATCH v2 2/2] coresight: Add remote etm support
config: arm-kismet-CONFIG_QCOM_QMI_HELPERS-CONFIG_CORESIGHT_REMOTE_ETM-0-0 (https://download.01.org/0day-ci/archive/20240808/202408080511.RIKNKoHh-lkp@intel.com/config)
reproduce: (https://download.01.org/0day-ci/archive/20240808/202408080511.RIKNKoHh-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408080511.RIKNKoHh-lkp@intel.com/

kismet warnings: (new ones prefixed by >>)
>> kismet: WARNING: unmet direct dependencies detected for QCOM_QMI_HELPERS when selected by CORESIGHT_REMOTE_ETM
   WARNING: unmet direct dependencies detected for QCOM_QMI_HELPERS
     Depends on [n]: NET [=n]
     Selected by [y]:
     - CORESIGHT_REMOTE_ETM [=y] && CORESIGHT [=y]
kernel test robot Aug. 7, 2024, 11 p.m. UTC | #2
Hi Mao,

kernel test robot noticed the following build errors:

[auto build test ERROR on robh/for-next]
[also build test ERROR on linus/master v6.11-rc2 next-20240807]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mao-Jinlong/dt-bindings-arm-Add-qcom-inst-id-for-remote-etm/20240807-151315
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20240807071054.12742-3-quic_jinlmao%40quicinc.com
patch subject: [PATCH v2 2/2] coresight: Add remote etm support
config: arm-allmodconfig (https://download.01.org/0day-ci/archive/20240808/202408080637.ZZJbuvB3-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240808/202408080637.ZZJbuvB3-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408080637.ZZJbuvB3-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/hwtracing/coresight/coresight-remote-etm.c:298:27: error: initialization of 'void (*)(struct platform_device *)' from incompatible pointer type 'int (*)(struct platform_device *)' [-Wincompatible-pointer-types]
     298 |         .remove         = remote_etm_remove,
         |                           ^~~~~~~~~~~~~~~~~
   drivers/hwtracing/coresight/coresight-remote-etm.c:298:27: note: (near initialization for 'remote_etm_driver.<anonymous>.remove')


vim +298 drivers/hwtracing/coresight/coresight-remote-etm.c

   295	
   296	static struct platform_driver remote_etm_driver = {
   297		.probe          = remote_etm_probe,
 > 298		.remove         = remote_etm_remove,
   299		.driver         = {
   300			.name   = "coresight-remote-etm",
   301			.of_match_table = remote_etm_match,
   302		},
   303	};
   304
kernel test robot Aug. 8, 2024, 2:03 a.m. UTC | #3
Hi Mao,

kernel test robot noticed the following build errors:

[auto build test ERROR on robh/for-next]
[also build test ERROR on linus/master v6.11-rc2 next-20240807]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mao-Jinlong/dt-bindings-arm-Add-qcom-inst-id-for-remote-etm/20240807-151315
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20240807071054.12742-3-quic_jinlmao%40quicinc.com
patch subject: [PATCH v2 2/2] coresight: Add remote etm support
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20240808/202408080922.hFC9XFAq-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 423aec6573df4424f90555468128e17073ddc69e)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240808/202408080922.hFC9XFAq-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408080922.hFC9XFAq-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/hwtracing/coresight/coresight-remote-etm.c:18:
   In file included from include/linux/coresight.h:9:
   In file included from include/linux/amba/bus.h:19:
   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:21:
   In file included from include/linux/mm.h:2228:
   include/linux/vmstat.h:500:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     500 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     501 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:507:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     507 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     508 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     514 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:519:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     519 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     520 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:528:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     528 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     529 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hwtracing/coresight/coresight-remote-etm.c:298:20: error: incompatible function pointer types initializing 'void (*)(struct platform_device *)' with an expression of type 'int (struct platform_device *)' [-Wincompatible-function-pointer-types]
     298 |         .remove         = remote_etm_remove,
         |                           ^~~~~~~~~~~~~~~~~
   5 warnings and 1 error generated.


vim +298 drivers/hwtracing/coresight/coresight-remote-etm.c

   295	
   296	static struct platform_driver remote_etm_driver = {
   297		.probe          = remote_etm_probe,
 > 298		.remove         = remote_etm_remove,
   299		.driver         = {
   300			.name   = "coresight-remote-etm",
   301			.of_match_table = remote_etm_match,
   302		},
   303	};
   304
diff mbox series

Patch

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 06f0a7594169..27a1c61613c7 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -247,4 +247,17 @@  config CORESIGHT_DUMMY
 
 	  To compile this driver as a module, choose M here: the module will be
 	  called coresight-dummy.
+
+config CORESIGHT_REMOTE_ETM
+	tristate "Remote processor ETM trace support"
+	select 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 4ba478211b31..e0781d729eb3 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -51,3 +51,4 @@  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
+obj-$(CONFIG_CORESIGHT_REMOTE_ETM) += coresight-remote-etm.o
diff --git a/drivers/hwtracing/coresight/coresight-qmi.h b/drivers/hwtracing/coresight/coresight-qmi.h
new file mode 100644
index 000000000000..76ce9b7fdf0a
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-qmi.h
@@ -0,0 +1,89 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _CORESIGHT_QMI_H
+#define _CORESIGHT_QMI_H
+
+#include <linux/soc/qcom/qmi.h>
+
+#define CORESIGHT_QMI_SVC_ID			(0x33)
+#define CORESIGHT_QMI_VERSION			(1)
+
+#define CORESIGHT_QMI_GET_ETM_REQ_V01		(0x002B)
+#define CORESIGHT_QMI_GET_ETM_RESP_V01		(0x002B)
+#define CORESIGHT_QMI_SET_ETM_REQ_V01		(0x002C)
+#define CORESIGHT_QMI_SET_ETM_RESP_V01		(0x002C)
+
+#define CORESIGHT_QMI_GET_ETM_REQ_MAX_LEN	(0)
+#define CORESIGHT_QMI_GET_ETM_RESP_MAX_LEN	(14)
+#define CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN	(7)
+#define CORESIGHT_QMI_SET_ETM_RESP_MAX_LEN	(7)
+
+#define TIMEOUT_MS				(10000)
+
+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,
+};
+
+struct coresight_set_etm_req_msg_v01 {
+	/* Mandatory */
+	/* ETM output state */
+	enum coresight_etm_state_enum_type_v01 state;
+};
+
+struct coresight_set_etm_resp_msg_v01 {
+	/* Mandatory */
+	struct qmi_response_type_v01 resp;
+};
+
+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,
+	},
+};
+
+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,
+	},
+};
+
+#endif
diff --git a/drivers/hwtracing/coresight/coresight-remote-etm.c b/drivers/hwtracing/coresight/coresight-remote-etm.c
new file mode 100644
index 000000000000..7d01e17b9210
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-remote-etm.c
@@ -0,0 +1,308 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023-2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/coresight.h>
+#include "coresight-qmi.h"
+#include "coresight-priv.h"
+
+DEFINE_CORESIGHT_DEVLIST(remote_etm_devs, "remote-etm");
+
+#define MAX_INSTANCE_ID		0xFF
+
+struct remote_etm_drvdata {
+	struct device			*dev;
+	struct coresight_device		*csdev;
+	struct mutex			mutex;
+	struct qmi_handle		handle;
+	u32				inst_id;
+	bool				enabled;
+	bool				service_connected;
+	struct sockaddr_qrtr		s_addr;
+};
+
+static int service_remote_etm_new_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct remote_etm_drvdata *drvdata = container_of(qmi,
+					struct remote_etm_drvdata, handle);
+
+	drvdata->s_addr.sq_family = AF_QIPCRTR;
+	drvdata->s_addr.sq_node = svc->node;
+	drvdata->s_addr.sq_port = svc->port;
+	drvdata->service_connected = true;
+	dev_info(drvdata->dev,
+		"Connection established between QMI handle and %d service\n",
+		drvdata->inst_id);
+
+	return 0;
+}
+
+static void service_remote_etm_del_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct remote_etm_drvdata *drvdata = container_of(qmi,
+					struct remote_etm_drvdata, handle);
+	drvdata->service_connected = false;
+	dev_info(drvdata->dev,
+		"Connection disconnected between QMI handle and %d service\n",
+		drvdata->inst_id);
+}
+
+static struct qmi_ops server_ops = {
+	.new_server = service_remote_etm_new_server,
+	.del_server = service_remote_etm_del_server,
+};
+
+static int remote_etm_enable(struct coresight_device *csdev,
+			     struct perf_event *event, u32 mode)
+{
+	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 } };
+	struct qmi_txn txn;
+	int ret;
+
+	mutex_lock(&drvdata->mutex);
+
+	if (!drvdata->service_connected) {
+		dev_err(drvdata->dev, "QMI service not connected!\n");
+		ret = -EINVAL;
+		goto err;
+	}
+	/*
+	 * The QMI handle may be NULL in the following scenarios:
+	 * 1. QMI service is not present
+	 * 2. QMI service is present but attempt to enable remote ETM is earlier
+	 *    than service is ready to handle request
+	 * 3. Connection between QMI client and QMI service failed
+	 *
+	 * Enable CoreSight without processing further QMI commands which
+	 * provides the option to enable remote ETM by other means.
+	 */
+	req.state = CORESIGHT_ETM_STATE_ENABLED_V01;
+
+	ret = qmi_txn_init(&drvdata->handle, &txn,
+			coresight_set_etm_resp_msg_v01_ei,
+			&resp);
+
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI tx init failed , ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	ret = qmi_send_request(&drvdata->handle, &drvdata->s_addr,
+			&txn, CORESIGHT_QMI_SET_ETM_REQ_V01,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			coresight_set_etm_req_msg_v01_ei,
+			&req);
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI send ACK failed, ret:%d\n",
+				ret);
+		qmi_txn_cancel(&txn);
+		goto err;
+	}
+
+	ret = qmi_txn_wait(&txn, msecs_to_jiffies(TIMEOUT_MS));
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI qmi txn wait failed, ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	/* Check the response */
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01)
+		dev_err(drvdata->dev, "QMI request failed 0x%x\n",
+				resp.resp.error);
+
+	drvdata->enabled = true;
+	mutex_unlock(&drvdata->mutex);
+
+	dev_dbg(drvdata->dev, "Remote ETM tracing enabled for instance %d\n",
+				drvdata->inst_id);
+	return 0;
+err:
+	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 } };
+	struct qmi_txn txn;
+	int ret;
+
+	mutex_lock(&drvdata->mutex);
+	if (!drvdata->service_connected) {
+		dev_err(drvdata->dev, "QMI service not connected!\n");
+		goto err;
+	}
+
+	req.state = CORESIGHT_ETM_STATE_DISABLED_V01;
+
+	ret = qmi_txn_init(&drvdata->handle, &txn,
+			coresight_set_etm_resp_msg_v01_ei,
+			&resp);
+
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI tx init failed , ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	ret = qmi_send_request(&drvdata->handle, &drvdata->s_addr,
+			&txn, CORESIGHT_QMI_SET_ETM_REQ_V01,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			coresight_set_etm_req_msg_v01_ei,
+			&req);
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI send req failed, ret:%d\n",
+				 ret);
+		qmi_txn_cancel(&txn);
+		goto err;
+	}
+
+	ret = qmi_txn_wait(&txn, msecs_to_jiffies(TIMEOUT_MS));
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI qmi txn wait failed, ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	/* Check the response */
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
+		dev_err(drvdata->dev, "QMI request failed 0x%x\n",
+				resp.resp.error);
+		goto err;
+	}
+
+	drvdata->enabled = false;
+	dev_info(drvdata->dev, "Remote ETM tracing disabled for instance %d\n",
+				drvdata->inst_id);
+err:
+	mutex_unlock(&drvdata->mutex);
+}
+
+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,
+};
+
+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;
+
+	pm_runtime_enable(dev);
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	ret = of_property_read_u32(pdev->dev.of_node, "qcom,inst-id",
+			&drvdata->inst_id);
+	if (ret)
+		return ret;
+
+	if (drvdata->inst_id >= MAX_INSTANCE_ID) {
+		dev_err(dev, "inst_id is invalid.\n");
+		return -EINVAL;
+	}
+
+	mutex_init(&drvdata->mutex);
+
+	ret = qmi_handle_init(&drvdata->handle,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			&server_ops, NULL);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "Remote ETM client init failed.\n");
+		return ret;
+	}
+
+	qmi_add_lookup(&drvdata->handle,
+			CORESIGHT_QMI_SVC_ID,
+			CORESIGHT_QMI_VERSION,
+			drvdata->inst_id);
+
+	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;
+	}
+
+	return 0;
+err:
+	qmi_handle_release(&drvdata->handle);
+	return ret;
+}
+
+static int remote_etm_remove(struct platform_device *pdev)
+{
+	struct remote_etm_drvdata *drvdata = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_disable(dev);
+	qmi_handle_release(&drvdata->handle);
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
+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");