drivers/coresight/coresight-rpm-etm.c - kernel/msm - Git at Google

 /* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #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/io.h>
 #include <linux/err.h>
 #include <linux/sysfs.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_coresight.h>
 #include <linux/coresight.h>
 #include "coresight-qmi.h"

 #ifdef CONFIG_CORESIGHT_RPM_ETM_DEFAULT_ENABLE
 static int boot_enable = 1;
 #else
 static int boot_enable;
 #endif
 module_param_named(
 	boot_enable, boot_enable, int, S_IRUGO
 );

 struct rpm_etm_drvdata {
 	struct device			*dev;
 	struct coresight_device		*csdev;
 	struct mutex			mutex;
 	struct workqueue_struct		*wq;
 	struct qmi_handle		*handle;
 	struct work_struct		work_svc_arrive;
 	struct work_struct		work_svc_exit;
 	struct work_struct		work_rcv_msg;
 	struct notifier_block		nb;
 	uint32_t			inst_id;
 };

 static int rpm_etm_enable(struct coresight_device *csdev)
 {
 	struct rpm_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 msg_desc req_desc, resp_desc;
 	int ret;

 	mutex_lock(&drvdata->mutex);

 	/*
 	 * 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.
 	 */
 	if (!drvdata->handle) {
 		dev_info(drvdata->dev,
 			 "%s: QMI service unavailable. Skipping QMI requests\n",
 			 __func__);
 		goto out;
 	}

 	req.state = CORESIGHT_ETM_STATE_ENABLED_V01;

 	req_desc.msg_id = CORESIGHT_QMI_SET_ETM_REQ_V01;
 	req_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN;
 	req_desc.ei_array = coresight_set_etm_req_msg_v01_ei;

 	resp_desc.msg_id = CORESIGHT_QMI_SET_ETM_RESP_V01;
 	resp_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_RESP_MAX_LEN;
 	resp_desc.ei_array = coresight_set_etm_resp_msg_v01_ei;

 	ret = qmi_send_req_wait(drvdata->handle, &req_desc, &req, sizeof(req),
 				&resp_desc, &resp, sizeof(resp), TIMEOUT_MS);

 	if (ret < 0) {
 		dev_err(drvdata->dev, "%s: QMI send req failed %d\n", __func__,
 			ret);
 		goto err;
 	}

 	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
 		dev_err(drvdata->dev, "%s: QMI request failed %d %d\n",
 			__func__, resp.resp.result, resp.resp.error);
 		ret = -EREMOTEIO;
 		goto err;
 	}
 out:
 	mutex_unlock(&drvdata->mutex);

 	dev_info(drvdata->dev, "RPM ETM tracing enabled\n");
 	return 0;
 err:
 	mutex_unlock(&drvdata->mutex);
 	return ret;
 }

 static void rpm_etm_disable(struct coresight_device *csdev)
 {
 	struct rpm_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 msg_desc req_desc, resp_desc;
 	int ret;

 	mutex_lock(&drvdata->mutex);

 	if (!drvdata->handle) {
 		dev_info(drvdata->dev,
 			 "%s: QMI service unavailable. Skipping QMI requests\n",
 			 __func__);
 		goto out;
 	}

 	req.state = CORESIGHT_ETM_STATE_DISABLED_V01;

 	req_desc.msg_id = CORESIGHT_QMI_SET_ETM_REQ_V01;
 	req_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN;
 	req_desc.ei_array = coresight_set_etm_req_msg_v01_ei;

 	resp_desc.msg_id = CORESIGHT_QMI_SET_ETM_RESP_V01;
 	resp_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_RESP_MAX_LEN;
 	resp_desc.ei_array = coresight_set_etm_resp_msg_v01_ei;

 	ret = qmi_send_req_wait(drvdata->handle, &req_desc, &req, sizeof(req),
 				&resp_desc, &resp, sizeof(resp), TIMEOUT_MS);
 	if (ret < 0) {
 		dev_err(drvdata->dev, "%s: QMI send req failed %d\n", __func__,
 			ret);
 		goto err;
 	}

 	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
 		dev_err(drvdata->dev, "%s: QMI request failed %d %d\n",
 			__func__, resp.resp.result, resp.resp.error);
 		goto err;
 	}
 out:
 	mutex_unlock(&drvdata->mutex);

 	dev_info(drvdata->dev, "RPM ETM tracing disabled\n");
 	return;
 err:
 	mutex_unlock(&drvdata->mutex);
 }

 static const struct coresight_ops_source rpm_etm_source_ops = {
 	.enable		= rpm_etm_enable,
 	.disable	= rpm_etm_disable,
 };

 static const struct coresight_ops rpm_cs_ops = {
 	.source_ops	= &rpm_etm_source_ops,
 };

 static void rpm_etm_rcv_msg(struct work_struct *work)
 {
 	struct rpm_etm_drvdata *drvdata = container_of(work,
 						       struct rpm_etm_drvdata,
 						       work_rcv_msg);

 	if (qmi_recv_msg(drvdata->handle) < 0)
 		dev_err(drvdata->dev, "%s: Error receiving QMI message\n",
 			__func__);
 }

 static void rpm_etm_notify(struct qmi_handle *handle,
 			   enum qmi_event_type event, void *notify_priv)
 {
 	struct rpm_etm_drvdata *drvdata =
 			(struct rpm_etm_drvdata *)notify_priv;
 	switch (event) {
 	case QMI_RECV_MSG:
 		queue_work(drvdata->wq, &drvdata->work_rcv_msg);
 		break;
 	default:
 		break;
 	}
 }

 static void rpm_etm_svc_arrive(struct work_struct *work)
 {
 	struct rpm_etm_drvdata *drvdata = container_of(work,
 						       struct rpm_etm_drvdata,
 						       work_svc_arrive);

 	drvdata->handle = qmi_handle_create(rpm_etm_notify, drvdata);
 	if (!drvdata->handle) {
 		dev_err(drvdata->dev, "%s: QMI client handle alloc failed\n",
 			__func__);
 		return;
 	}

 	if (qmi_connect_to_service(drvdata->handle, CORESIGHT_QMI_SVC_ID,
 				   CORESIGHT_QMI_VERSION,
 				   drvdata->inst_id) < 0) {
 		dev_err(drvdata->dev,
 			"%s: Could not connect handle to service\n", __func__);
 		qmi_handle_destroy(drvdata->handle);
 		drvdata->handle = NULL;
 	}
 }

 static void rpm_etm_svc_exit(struct work_struct *work)
 {
 	struct rpm_etm_drvdata *drvdata = container_of(work,
 						       struct rpm_etm_drvdata,
 						       work_svc_exit);

 	qmi_handle_destroy(drvdata->handle);
 	drvdata->handle = NULL;
 }

 static int rpm_etm_svc_event_notify(struct notifier_block *this,
 				    unsigned long event,
 				    void *data)
 {
 	struct rpm_etm_drvdata *drvdata = container_of(this,
 						       struct rpm_etm_drvdata,
 						       nb);

 	switch (event) {
 	case QMI_SERVER_ARRIVE:
 		queue_work(drvdata->wq, &drvdata->work_svc_arrive);
 		break;
 	case QMI_SERVER_EXIT:
 		queue_work(drvdata->wq, &drvdata->work_svc_exit);
 		break;
 	default:
 		break;
 	}
 	return 0;
 }

 static int rpm_etm_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct coresight_platform_data *pdata;
 	struct rpm_etm_drvdata *drvdata;
 	struct coresight_desc *desc;
 	int ret;

 	if (pdev->dev.of_node) {
 		pdata = of_get_coresight_platform_data(dev, pdev->dev.of_node);
 		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 = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 	if (!desc)
 		return -ENOMEM;

 	if (pdev->dev.of_node) {
 		ret = of_property_read_u32(pdev->dev.of_node, "qcom,inst-id",
 					   &drvdata->inst_id);
 		if (ret)
 			drvdata->inst_id = CORESIGHT_SVC_INST_ID_RPM_V01;
 	}

 	mutex_init(&drvdata->mutex);

 	drvdata->nb.notifier_call = rpm_etm_svc_event_notify;

 	drvdata->wq = create_singlethread_workqueue("rpm-etm");
 	if (!drvdata->wq)
 		return -EFAULT;
 	INIT_WORK(&drvdata->work_svc_arrive, rpm_etm_svc_arrive);
 	INIT_WORK(&drvdata->work_svc_exit, rpm_etm_svc_exit);
 	INIT_WORK(&drvdata->work_rcv_msg, rpm_etm_rcv_msg);
 	ret = qmi_svc_event_notifier_register(CORESIGHT_QMI_SVC_ID,
 					      CORESIGHT_QMI_VERSION,
 					      drvdata->inst_id,
 					      &drvdata->nb);
 	if (ret < 0)
 		goto err0;

 	desc->type = CORESIGHT_DEV_TYPE_SOURCE;
 	desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
 	desc->ops = &rpm_cs_ops;
 	desc->pdata = pdev->dev.platform_data;
 	desc->dev = &pdev->dev;
 	desc->owner = THIS_MODULE;
 	drvdata->csdev = coresight_register(desc);
 	if (IS_ERR(drvdata->csdev)) {
 		ret = PTR_ERR(drvdata->csdev);
 		goto err1;
 	}
 	dev_info(dev, "RPM ETM initialized\n");

 	if (boot_enable)
 		coresight_enable(drvdata->csdev);

 	return 0;
 err1:
 	qmi_svc_event_notifier_unregister(CORESIGHT_QMI_SVC_ID,
 					  CORESIGHT_QMI_VERSION,
 					  drvdata->inst_id,
 					  &drvdata->nb);
 err0:
 	destroy_workqueue(drvdata->wq);
 	return ret;
 }

 static int rpm_etm_remove(struct platform_device *pdev)
 {
 	struct rpm_etm_drvdata *drvdata = platform_get_drvdata(pdev);

 	coresight_unregister(drvdata->csdev);
 	return 0;
 }

 static struct of_device_id rpm_etm_match[] = {
 	{.compatible = "qcom,coresight-rpm-etm"},
 	{}
 };

 static struct platform_driver rpm_etm_driver = {
 	.probe          = rpm_etm_probe,
 	.remove         = rpm_etm_remove,
 	.driver         = {
 		.name   = "coresight-rpm-etm",
 		.owner	= THIS_MODULE,
 		.of_match_table = rpm_etm_match,
 	},
 };

 int __init rpm_etm_init(void)
 {
 	return platform_driver_register(&rpm_etm_driver);
 }
 module_init(rpm_etm_init);

 void __exit rpm_etm_exit(void)
 {
 	platform_driver_unregister(&rpm_etm_driver);
 }
 module_exit(rpm_etm_exit);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("CoreSight RPM ETM driver");
	/* Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#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/io.h>
	#include <linux/err.h>
	#include <linux/sysfs.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/of_coresight.h>
	#include <linux/coresight.h>
	#include "coresight-qmi.h"

	#ifdef CONFIG_CORESIGHT_RPM_ETM_DEFAULT_ENABLE
	static int boot_enable = 1;
	#else
	static int boot_enable;
	#endif
	module_param_named(
	boot_enable, boot_enable, int, S_IRUGO
	);

	struct rpm_etm_drvdata {
	struct device *dev;
	struct coresight_device *csdev;
	struct mutex mutex;
	struct workqueue_struct *wq;
	struct qmi_handle *handle;
	struct work_struct work_svc_arrive;
	struct work_struct work_svc_exit;
	struct work_struct work_rcv_msg;
	struct notifier_block nb;
	uint32_t inst_id;
	};

	static int rpm_etm_enable(struct coresight_device *csdev)
	{
	struct rpm_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 msg_desc req_desc, resp_desc;
	int ret;

	mutex_lock(&drvdata->mutex);

	/*
	* 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.
	*/
	if (!drvdata->handle) {
	dev_info(drvdata->dev,
	"%s: QMI service unavailable. Skipping QMI requests\n",
	__func__);
	goto out;
	}

	req.state = CORESIGHT_ETM_STATE_ENABLED_V01;

	req_desc.msg_id = CORESIGHT_QMI_SET_ETM_REQ_V01;
	req_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN;
	req_desc.ei_array = coresight_set_etm_req_msg_v01_ei;

	resp_desc.msg_id = CORESIGHT_QMI_SET_ETM_RESP_V01;
	resp_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_RESP_MAX_LEN;
	resp_desc.ei_array = coresight_set_etm_resp_msg_v01_ei;

	ret = qmi_send_req_wait(drvdata->handle, &req_desc, &req, sizeof(req),
	&resp_desc, &resp, sizeof(resp), TIMEOUT_MS);

	if (ret < 0) {
	dev_err(drvdata->dev, "%s: QMI send req failed %d\n", __func__,
	ret);
	goto err;
	}

	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
	dev_err(drvdata->dev, "%s: QMI request failed %d %d\n",
	__func__, resp.resp.result, resp.resp.error);
	ret = -EREMOTEIO;
	goto err;
	}
	out:
	mutex_unlock(&drvdata->mutex);

	dev_info(drvdata->dev, "RPM ETM tracing enabled\n");
	return 0;
	err:
	mutex_unlock(&drvdata->mutex);
	return ret;
	}

	static void rpm_etm_disable(struct coresight_device *csdev)
	{
	struct rpm_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 msg_desc req_desc, resp_desc;
	int ret;

	mutex_lock(&drvdata->mutex);

	if (!drvdata->handle) {
	dev_info(drvdata->dev,
	"%s: QMI service unavailable. Skipping QMI requests\n",
	__func__);
	goto out;
	}

	req.state = CORESIGHT_ETM_STATE_DISABLED_V01;

	req_desc.msg_id = CORESIGHT_QMI_SET_ETM_REQ_V01;
	req_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN;
	req_desc.ei_array = coresight_set_etm_req_msg_v01_ei;

	resp_desc.msg_id = CORESIGHT_QMI_SET_ETM_RESP_V01;
	resp_desc.max_msg_len = CORESIGHT_QMI_SET_ETM_RESP_MAX_LEN;
	resp_desc.ei_array = coresight_set_etm_resp_msg_v01_ei;

	ret = qmi_send_req_wait(drvdata->handle, &req_desc, &req, sizeof(req),
	&resp_desc, &resp, sizeof(resp), TIMEOUT_MS);
	if (ret < 0) {
	dev_err(drvdata->dev, "%s: QMI send req failed %d\n", __func__,
	ret);
	goto err;
	}

	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
	dev_err(drvdata->dev, "%s: QMI request failed %d %d\n",
	__func__, resp.resp.result, resp.resp.error);
	goto err;
	}
	out:
	mutex_unlock(&drvdata->mutex);

	dev_info(drvdata->dev, "RPM ETM tracing disabled\n");
	return;
	err:
	mutex_unlock(&drvdata->mutex);
	}

	static const struct coresight_ops_source rpm_etm_source_ops = {
	.enable = rpm_etm_enable,
	.disable = rpm_etm_disable,
	};

	static const struct coresight_ops rpm_cs_ops = {
	.source_ops = &rpm_etm_source_ops,
	};

	static void rpm_etm_rcv_msg(struct work_struct *work)
	{
	struct rpm_etm_drvdata *drvdata = container_of(work,
	struct rpm_etm_drvdata,
	work_rcv_msg);

	if (qmi_recv_msg(drvdata->handle) < 0)
	dev_err(drvdata->dev, "%s: Error receiving QMI message\n",
	__func__);
	}

	static void rpm_etm_notify(struct qmi_handle *handle,
	enum qmi_event_type event, void *notify_priv)
	{
	struct rpm_etm_drvdata *drvdata =
	(struct rpm_etm_drvdata *)notify_priv;
	switch (event) {
	case QMI_RECV_MSG:
	queue_work(drvdata->wq, &drvdata->work_rcv_msg);
	break;
	default:
	break;
	}
	}

	static void rpm_etm_svc_arrive(struct work_struct *work)
	{
	struct rpm_etm_drvdata *drvdata = container_of(work,
	struct rpm_etm_drvdata,
	work_svc_arrive);

	drvdata->handle = qmi_handle_create(rpm_etm_notify, drvdata);
	if (!drvdata->handle) {
	dev_err(drvdata->dev, "%s: QMI client handle alloc failed\n",
	__func__);
	return;
	}

	if (qmi_connect_to_service(drvdata->handle, CORESIGHT_QMI_SVC_ID,
	CORESIGHT_QMI_VERSION,
	drvdata->inst_id) < 0) {
	dev_err(drvdata->dev,
	"%s: Could not connect handle to service\n", __func__);
	qmi_handle_destroy(drvdata->handle);
	drvdata->handle = NULL;
	}
	}

	static void rpm_etm_svc_exit(struct work_struct *work)
	{
	struct rpm_etm_drvdata *drvdata = container_of(work,
	struct rpm_etm_drvdata,
	work_svc_exit);

	qmi_handle_destroy(drvdata->handle);
	drvdata->handle = NULL;
	}

	static int rpm_etm_svc_event_notify(struct notifier_block *this,
	unsigned long event,
	void *data)
	{
	struct rpm_etm_drvdata *drvdata = container_of(this,
	struct rpm_etm_drvdata,
	nb);

	switch (event) {
	case QMI_SERVER_ARRIVE:
	queue_work(drvdata->wq, &drvdata->work_svc_arrive);
	break;
	case QMI_SERVER_EXIT:
	queue_work(drvdata->wq, &drvdata->work_svc_exit);
	break;
	default:
	break;
	}
	return 0;
	}

	static int rpm_etm_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct coresight_platform_data *pdata;
	struct rpm_etm_drvdata *drvdata;
	struct coresight_desc *desc;
	int ret;

	if (pdev->dev.of_node) {
	pdata = of_get_coresight_platform_data(dev, pdev->dev.of_node);
	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 = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
	if (!desc)
	return -ENOMEM;

	if (pdev->dev.of_node) {
	ret = of_property_read_u32(pdev->dev.of_node, "qcom,inst-id",
	&drvdata->inst_id);
	if (ret)
	drvdata->inst_id = CORESIGHT_SVC_INST_ID_RPM_V01;
	}

	mutex_init(&drvdata->mutex);

	drvdata->nb.notifier_call = rpm_etm_svc_event_notify;

	drvdata->wq = create_singlethread_workqueue("rpm-etm");
	if (!drvdata->wq)
	return -EFAULT;
	INIT_WORK(&drvdata->work_svc_arrive, rpm_etm_svc_arrive);
	INIT_WORK(&drvdata->work_svc_exit, rpm_etm_svc_exit);
	INIT_WORK(&drvdata->work_rcv_msg, rpm_etm_rcv_msg);
	ret = qmi_svc_event_notifier_register(CORESIGHT_QMI_SVC_ID,
	CORESIGHT_QMI_VERSION,
	drvdata->inst_id,
	&drvdata->nb);
	if (ret < 0)
	goto err0;

	desc->type = CORESIGHT_DEV_TYPE_SOURCE;
	desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
	desc->ops = &rpm_cs_ops;
	desc->pdata = pdev->dev.platform_data;
	desc->dev = &pdev->dev;
	desc->owner = THIS_MODULE;
	drvdata->csdev = coresight_register(desc);
	if (IS_ERR(drvdata->csdev)) {
	ret = PTR_ERR(drvdata->csdev);
	goto err1;
	}
	dev_info(dev, "RPM ETM initialized\n");

	if (boot_enable)
	coresight_enable(drvdata->csdev);

	return 0;
	err1:
	qmi_svc_event_notifier_unregister(CORESIGHT_QMI_SVC_ID,
	CORESIGHT_QMI_VERSION,
	drvdata->inst_id,
	&drvdata->nb);
	err0:
	destroy_workqueue(drvdata->wq);
	return ret;
	}

	static int rpm_etm_remove(struct platform_device *pdev)
	{
	struct rpm_etm_drvdata *drvdata = platform_get_drvdata(pdev);

	coresight_unregister(drvdata->csdev);
	return 0;
	}

	static struct of_device_id rpm_etm_match[] = {
	{.compatible = "qcom,coresight-rpm-etm"},
	{}
	};

	static struct platform_driver rpm_etm_driver = {
	.probe = rpm_etm_probe,
	.remove = rpm_etm_remove,
	.driver = {
	.name = "coresight-rpm-etm",
	.owner = THIS_MODULE,
	.of_match_table = rpm_etm_match,
	},
	};

	int __init rpm_etm_init(void)
	{
	return platform_driver_register(&rpm_etm_driver);
	}
	module_init(rpm_etm_init);

	void __exit rpm_etm_exit(void)
	{
	platform_driver_unregister(&rpm_etm_driver);
	}
	module_exit(rpm_etm_exit);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("CoreSight RPM ETM driver");