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Commit 5276454d authored by Shashank Mittal's avatar Shashank Mittal Committed by Satyajit Desai
Browse files

coresight-dummy: add dummy driver support for source devices 



Add driver support to configure dummy Coresight source
devices. This driver can be used for devices that are
controlled by other subsystems but rely on Linux drivers
to configure rest of the trace path.

Change-Id: I7b68202fc6d7958fcf7ff933d7eed7e19c958ab0
Signed-off-by: default avatarShashank Mittal <mittals@codeaurora.org>
Signed-off-by: default avatarSatyajit Desai <sadesai@codeaurora.org>
parent e6ccf71c

drivers/hwtracing/coresight/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -149,4 +149,12 @@ config CORESIGHT_HWEVENT 
	  Hardware Event across STM interface. It configures Coresight

	  Hardware Event mux control registers to select hardware events

	  based on user input.



config CORESIGHT_DUMMY

	bool "Dummy driver support"

	help

	  Enables support for dummy driver. Dummy driver can be

	  used for CoreSight sources/sinks that are owned and configured by some other

	  subsystem and use Linux drivers to configure rest of trace path.



endif

drivers/hwtracing/coresight/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -22,3 +22,4 @@ obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o 
obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o

obj-$(CONFIG_CORESIGHT_CSR) += coresight-csr.o

obj-$(CONFIG_CORESIGHT_HWEVENT) += coresight-hwevent.o

obj-$(CONFIG_CORESIGHT_SOURCE_DUMMY) += coresight-dummy.o

drivers/hwtracing/coresight/coresight-dummy.c

0 → 100644
+137 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2016-2017, 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/platform_device.h>

#include <linux/coresight.h>



#define DUMMY_TRACE_ID_START	256



struct dummy_drvdata {

	struct device			*dev;

	struct coresight_device		*csdev;

	int				traceid;

};



static int dummy_source_enable(struct coresight_device *csdev,

			       struct perf_event *event, u32 mode)

{

	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);



	dev_info(drvdata->dev, "Dummy source enabled\n");



	return 0;

}



static void dummy_source_disable(struct coresight_device *csdev,

				 struct perf_event *event)

{

	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);



	dev_info(drvdata->dev, "Dummy source disabled\n");

}



static int dummy_trace_id(struct coresight_device *csdev)

{

	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);



	return drvdata->traceid;

}



static const struct coresight_ops_source dummy_source_ops = {

	.trace_id	= dummy_trace_id,

	.enable		= dummy_source_enable,

	.disable	= dummy_source_disable,

};



static const struct coresight_ops dummy_cs_ops = {

	.source_ops	= &dummy_source_ops,

};



static int dummy_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct coresight_platform_data *pdata;

	struct dummy_drvdata *drvdata;

	struct coresight_desc *desc;

	static int traceid = DUMMY_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;



	drvdata->traceid = traceid++;



	desc->type = CORESIGHT_DEV_TYPE_SOURCE;

	desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;

	desc->ops = &dummy_cs_ops;

	desc->pdata = pdev->dev.platform_data;

	desc->dev = &pdev->dev;

	drvdata->csdev = coresight_register(desc);

	if (IS_ERR(drvdata->csdev))

		return PTR_ERR(drvdata->csdev);



	dev_info(dev, "Dummy device initialized\n");



	return 0;

}



static int dummy_remove(struct platform_device *pdev)

{

	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);



	coresight_unregister(drvdata->csdev);

	return 0;

}



static const struct of_device_id dummy_match[] = {

	{.compatible = "qcom,coresight-dummy"},

	{}

};



static struct platform_driver dummy_driver = {

	.probe	= dummy_probe,

	.remove	= dummy_remove,

	.driver	= {

		.name   = "coresight-dummy",

		.owner	= THIS_MODULE,

		.of_match_table = dummy_match,

	},

};



int __init dummy_init(void)

{

	return platform_driver_register(&dummy_driver);

}

module_init(dummy_init);



void __exit dummy_exit(void)

{

	platform_driver_unregister(&dummy_driver);

}

module_exit(dummy_exit);



MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("CoreSight dummy source driver");