1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
  4 */
  5
  6#include <linux/coresight.h>
  7#include <linux/kernel.h>
  8#include <linux/module.h>
  9#include <linux/of.h>
 10#include <linux/platform_device.h>
 11#include <linux/pm_runtime.h>
 12
 13#include "coresight-priv.h"
 14
 15struct dummy_drvdata {
 16	struct device			*dev;
 17	struct coresight_device		*csdev;
 18};
 19
 20DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
 21DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");
 22
 23static int dummy_source_enable(struct coresight_device *csdev,
 24			       struct perf_event *event, enum cs_mode mode,
 25			       __maybe_unused struct coresight_trace_id_map *id_map)
 26{
 27	if (!coresight_take_mode(csdev, mode))
 28		return -EBUSY;
 29
 30	dev_dbg(csdev->dev.parent, "Dummy source enabled\n");
 31
 32	return 0;
 33}
 34
 35static void dummy_source_disable(struct coresight_device *csdev,
 36				 struct perf_event *event)
 37{
 38	coresight_set_mode(csdev, CS_MODE_DISABLED);
 39	dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
 40}
 41
 42static int dummy_sink_enable(struct coresight_device *csdev, enum cs_mode mode,
 43				void *data)
 44{
 45	dev_dbg(csdev->dev.parent, "Dummy sink enabled\n");
 46
 47	return 0;
 48}
 49
 50static int dummy_sink_disable(struct coresight_device *csdev)
 51{
 52	dev_dbg(csdev->dev.parent, "Dummy sink disabled\n");
 53
 54	return 0;
 55}
 56
 57static const struct coresight_ops_source dummy_source_ops = {
 58	.enable	= dummy_source_enable,
 59	.disable = dummy_source_disable,
 60};
 61
 62static const struct coresight_ops dummy_source_cs_ops = {
 63	.source_ops = &dummy_source_ops,
 64};
 65
 66static const struct coresight_ops_sink dummy_sink_ops = {
 67	.enable	= dummy_sink_enable,
 68	.disable = dummy_sink_disable,
 69};
 70
 71static const struct coresight_ops dummy_sink_cs_ops = {
 72	.sink_ops = &dummy_sink_ops,
 73};
 74
 75static int dummy_probe(struct platform_device *pdev)
 76{
 77	struct device *dev = &pdev->dev;
 78	struct device_node *node = dev->of_node;
 79	struct coresight_platform_data *pdata;
 80	struct dummy_drvdata *drvdata;
 81	struct coresight_desc desc = { 0 };
 82
 83	if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
 84
 85		desc.name = coresight_alloc_device_name(&source_devs, dev);
 86		if (!desc.name)
 87			return -ENOMEM;
 88
 89		desc.type = CORESIGHT_DEV_TYPE_SOURCE;
 90		desc.subtype.source_subtype =
 91					CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
 92		desc.ops = &dummy_source_cs_ops;
 93	} else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) {
 94		desc.name = coresight_alloc_device_name(&sink_devs, dev);
 95		if (!desc.name)
 96			return -ENOMEM;
 97
 98		desc.type = CORESIGHT_DEV_TYPE_SINK;
 99		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_DUMMY;
100		desc.ops = &dummy_sink_cs_ops;
101	} else {
102		dev_err(dev, "Device type not set\n");
103		return -EINVAL;
104	}
105
106	pdata = coresight_get_platform_data(dev);
107	if (IS_ERR(pdata))
108		return PTR_ERR(pdata);
109	pdev->dev.platform_data = pdata;
110
111	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
112	if (!drvdata)
113		return -ENOMEM;
114
115	drvdata->dev = &pdev->dev;
116	platform_set_drvdata(pdev, drvdata);
117
118	desc.pdata = pdev->dev.platform_data;
119	desc.dev = &pdev->dev;
120	drvdata->csdev = coresight_register(&desc);
121	if (IS_ERR(drvdata->csdev))
122		return PTR_ERR(drvdata->csdev);
123
124	pm_runtime_enable(dev);
125	dev_dbg(dev, "Dummy device initialized\n");
126
127	return 0;
128}
129
130static void dummy_remove(struct platform_device *pdev)
131{
132	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
133	struct device *dev = &pdev->dev;
134
135	pm_runtime_disable(dev);
136	coresight_unregister(drvdata->csdev);
137}
138
139static const struct of_device_id dummy_match[] = {
140	{.compatible = "arm,coresight-dummy-source"},
141	{.compatible = "arm,coresight-dummy-sink"},
142	{},
143};
144
145static struct platform_driver dummy_driver = {
146	.probe	= dummy_probe,
147	.remove = dummy_remove,
148	.driver	= {
149		.name   = "coresight-dummy",
150		.of_match_table = dummy_match,
151	},
152};
153
154module_platform_driver(dummy_driver);
155
156MODULE_LICENSE("GPL");
157MODULE_DESCRIPTION("CoreSight dummy driver");