coresight: add remote etm driver support in upstream implementation

Add remote etm driver in upstream implementation of Coresight
driver.
This change copies coresight-remote-etm.c file from drivers/coresight
(commit c1fe9ac38d93 ("input: touchscreen: correct function and variable
names in ITE tech driver"))
to driver/hwtracing/coresight directory.

Change-Id: I77a1aaf10aaf3f3010ab19d5878bb53dcc504c29
Signed-off-by: Shashank Mittal <mittals@codeaurora.org>

Documentation/devicetree/bindings/arm/coresight.txt

@@ -47,6 +47,7 @@ its hardware characteristcs.
 		- "arm,coresight-cti"
 		- "qcom,coresight-tpda"
 		- "qcom,coresight-tpdm"
+		- "qcom,coresight-remote-etm"
 
 	* port or ports: same as above.
 
@@ -97,6 +98,10 @@ its hardware characteristcs.
 	* qcom,msr-fix-req: boolean, indicating if MSRs need to be programmed
 	  after enabling the subunit.
 
+* Required property for Remote ETMs:
+
+	* qcom,inst-id: must be present. QMI instance id for remote ETMs.
+
 Example:
 
 1. Sinks

drivers/hwtracing/coresight/Kconfig

@@ -79,6 +79,22 @@ config CORESIGHT_SOURCE_ETM4X
 	  for instruction level tracing. Depending on the implemented version
 	  data tracing may also be available.
 
+config CORESIGHT_REMOTE_ETM
+	bool "Remote processor ETM trace support"
+	depends on MSM_QMI_INTERFACE
+	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.
+
+config CORESIGHT_REMOTE_ETM_DEFAULT_ENABLE
+	int "default enable bits for Remote processor ETM"
+	depends on CORESIGHT_REMOTE_ETM
+	help
+	  Support for enabling separated Remote processor ETM tracing. Depends
+	  on if instance id bit is set.
+
 config CORESIGHT_QCOM_REPLICATOR
 	bool "Qualcomm CoreSight Replicator driver"
 	depends on CORESIGHT_LINKS_AND_SINKS

drivers/hwtracing/coresight/Makefile

@@ -16,3 +16,4 @@ obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
 obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o
 obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
 obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o
+obj-$(CONFIG_CORESIGHT_REMOTE_ETM) += coresight-remote-etm.o

drivers/hwtracing/coresight/coresight-qmi.h

@@ -0,0 +1,116 @@
+/* Copyright (c) 2014-2016, 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.
+ */
+
+#ifndef _CORESIGHT_QMI_H
+#define _CORESIGHT_QMI_H
+
+#include <soc/qcom/msm_qmi_interface.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				(5000)
+
+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_get_etm_req_msg_v01 {
+	/*
+	 * This element is a placeholder to prevent declaration of
+	 * empty struct. Do not change.
+	 */
+	char __placeholder;
+};
+
+struct coresight_get_etm_resp_msg_v01 {
+	/* Mandatory */
+	/* QMI result Code */
+	struct qmi_response_type_v01 resp;
+
+	/* Optional */
+	/* ETM output state, must be set to true if state is being passed */
+	uint8_t state_valid;
+	/* Present when result code is QMI_RESULT_SUCCESS */
+	enum coresight_etm_state_enum_type_v01 state;
+};
+
+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 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),
+		.is_array  = 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,
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0,
+		.offset    = 0,
+		.ei_array  = NULL,
+	},
+};
+
+static struct elem_info coresight_set_etm_resp_msg_v01_ei[] = {
+	{
+		.data_type = QMI_STRUCT,
+		.elem_len  = 1,
+		.elem_size = sizeof(struct qmi_response_type_v01),
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0x02,
+		.offset    = offsetof(struct coresight_set_etm_resp_msg_v01,
+				      resp),
+		.ei_array  = get_qmi_response_type_v01_ei(),
+	},
+	{
+		.data_type = QMI_EOTI,
+		.elem_len  = 0,
+		.elem_size = 0,
+		.is_array  = NO_ARRAY,
+		.tlv_type  = 0,
+		.offset    = 0,
+		.ei_array  = NULL,
+	},
+};
+
+#endif

drivers/hwtracing/coresight/coresight-remote-etm.c

@@ -0,0 +1,395 @@
+/* Copyright (c) 2013-2016, 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/coresight.h>
+#include "coresight-qmi.h"
+
+#define REMOTE_ETM_TRACE_ID_START	192
+
+#ifdef CONFIG_CORESIGHT_REMOTE_ETM_DEFAULT_ENABLE
+static int boot_enable = CONFIG_CORESIGHT_REMOTE_ETM_DEFAULT_ENABLE;
+#else
+static int boot_enable;
+#endif
+
+module_param_named(
+	boot_enable, boot_enable, int, S_IRUGO
+);
+
+struct remote_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;
+	struct delayed_work		work_delay_enable;
+	bool				enable;
+	int				traceid;
+};
+
+static int remote_etm_enable(struct coresight_device *csdev)
+{
+	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 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\n",  __func__);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	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;
+	}
+	drvdata->enable = true;
+	mutex_unlock(&drvdata->mutex);
+
+	dev_info(drvdata->dev, "Remote ETM tracing enabled\n");
+	return 0;
+err:
+	mutex_unlock(&drvdata->mutex);
+	return ret;
+}
+
+static void remote_etm_disable(struct coresight_device *csdev)
+{
+	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 msg_desc req_desc, resp_desc;
+	int ret;
+
+	mutex_lock(&drvdata->mutex);
+
+	if (!drvdata->handle) {
+		dev_info(drvdata->dev,
+			 "%s: QMI service unavailable\n",  __func__);
+		goto err;
+	}
+
+	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;
+	}
+	drvdata->enable = false;
+	mutex_unlock(&drvdata->mutex);
+
+	dev_info(drvdata->dev, "Remote ETM tracing disabled\n");
+	return;
+err:
+	mutex_unlock(&drvdata->mutex);
+}
+
+static int remote_etm_trace_id(struct coresight_device *csdev)
+{
+	struct remote_etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	return drvdata->traceid;
+}
+
+static const struct coresight_ops_source remote_etm_source_ops = {
+	.trace_id	= remote_etm_trace_id,
+	.enable		= remote_etm_enable,
+	.disable	= remote_etm_disable,
+};
+
+static const struct coresight_ops remote_cs_ops = {
+	.source_ops	= &remote_etm_source_ops,
+};
+
+static void remote_etm_rcv_msg(struct work_struct *work)
+{
+	struct remote_etm_drvdata *drvdata = container_of(work,
+						struct remote_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 remote_etm_notify(struct qmi_handle *handle,
+			   enum qmi_event_type event, void *notify_priv)
+{
+	struct remote_etm_drvdata *drvdata =
+			(struct remote_etm_drvdata *)notify_priv;
+	switch (event) {
+	case QMI_RECV_MSG:
+		queue_work(drvdata->wq, &drvdata->work_rcv_msg);
+		break;
+	default:
+		break;
+	}
+}
+
+static void remote_delay_enable_handler(struct work_struct *work)
+{
+	struct remote_etm_drvdata *drvdata = container_of(work,
+						struct remote_etm_drvdata,
+						work_delay_enable.work);
+	coresight_enable(drvdata->csdev);
+}
+
+static void remote_etm_svc_arrive(struct work_struct *work)
+{
+	struct remote_etm_drvdata *drvdata = container_of(work,
+						struct remote_etm_drvdata,
+						work_svc_arrive);
+
+	drvdata->handle = qmi_handle_create(remote_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;
+	}
+
+	mutex_lock(&drvdata->mutex);
+	if (drvdata->inst_id < sizeof(int)*BITS_PER_BYTE
+	    && (boot_enable & BIT(drvdata->inst_id))) {
+		if (!drvdata->enable)
+			schedule_delayed_work(&drvdata->work_delay_enable,
+					      msecs_to_jiffies(TIMEOUT_MS));
+	}
+	mutex_unlock(&drvdata->mutex);
+}
+
+static void remote_etm_svc_exit(struct work_struct *work)
+{
+	struct remote_etm_drvdata *drvdata = container_of(work,
+						struct remote_etm_drvdata,
+						work_svc_exit);
+
+	qmi_handle_destroy(drvdata->handle);
+	drvdata->handle = NULL;
+}
+
+static int remote_etm_svc_event_notify(struct notifier_block *this,
+				    unsigned long event,
+				    void *data)
+{
+	struct remote_etm_drvdata *drvdata = container_of(this,
+						struct remote_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 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;
+	int ret;
+	static int traceid = REMOTE_ETM_TRACE_ID_START;
+
+	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;
+
+	ret = of_property_read_u32(pdev->dev.of_node, "qcom,inst-id",
+			&drvdata->inst_id);
+	if (ret)
+		return ret;
+
+	mutex_init(&drvdata->mutex);
+
+	drvdata->nb.notifier_call = remote_etm_svc_event_notify;
+
+	drvdata->wq = create_singlethread_workqueue(dev_name(dev));
+	if (!drvdata->wq)
+		return -EFAULT;
+	INIT_WORK(&drvdata->work_svc_arrive, remote_etm_svc_arrive);
+	INIT_WORK(&drvdata->work_svc_exit, remote_etm_svc_exit);
+	INIT_WORK(&drvdata->work_rcv_msg, remote_etm_rcv_msg);
+	INIT_DELAYED_WORK(&drvdata->work_delay_enable,
+			  remote_delay_enable_handler);
+	ret = qmi_svc_event_notifier_register(CORESIGHT_QMI_SVC_ID,
+					      CORESIGHT_QMI_VERSION,
+					      drvdata->inst_id,
+					      &drvdata->nb);
+	if (ret < 0)
+		goto err0;
+
+	drvdata->traceid = traceid++;
+
+	desc->type = CORESIGHT_DEV_TYPE_SOURCE;
+	desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
+	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 err1;
+	}
+	dev_info(dev, "Remote ETM initialized\n");
+
+	if (drvdata->inst_id >= sizeof(int)*BITS_PER_BYTE)
+		dev_err(dev, "inst_id greater than boot_enable bit mask\n");
+	else if (boot_enable & BIT(drvdata->inst_id))
+		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 remote_etm_remove(struct platform_device *pdev)
+{
+	struct remote_etm_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	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",
+		.owner	= THIS_MODULE,
+		.of_match_table = remote_etm_match,
+	},
+};
+
+int __init remote_etm_init(void)
+{
+	return platform_driver_register(&remote_etm_driver);
+}
+module_init(remote_etm_init);
+
+void __exit remote_etm_exit(void)
+{
+	platform_driver_unregister(&remote_etm_driver);
+}
+module_exit(remote_etm_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("CoreSight Remote ETM driver");