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{
 26	dev_dbg(csdev->dev.parent, "Dummy source enabled\n");
 27
 28	return 0;
 29}
 30
 31static void dummy_source_disable(struct coresight_device *csdev,
 32				 struct perf_event *event)
 33{
 34	dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
 35}
 36
 37static int dummy_sink_enable(struct coresight_device *csdev, enum cs_mode mode,
 38				void *data)
 39{
 40	dev_dbg(csdev->dev.parent, "Dummy sink enabled\n");
 41
 42	return 0;
 43}
 44
 45static int dummy_sink_disable(struct coresight_device *csdev)
 46{
 47	dev_dbg(csdev->dev.parent, "Dummy sink disabled\n");
 48
 49	return 0;
 50}
 51
 52static const struct coresight_ops_source dummy_source_ops = {
 53	.enable	= dummy_source_enable,
 54	.disable = dummy_source_disable,
 55};
 56
 57static const struct coresight_ops dummy_source_cs_ops = {
 58	.source_ops = &dummy_source_ops,
 59};
 60
 61static const struct coresight_ops_sink dummy_sink_ops = {
 62	.enable	= dummy_sink_enable,
 63	.disable = dummy_sink_disable,
 64};
 65
 66static const struct coresight_ops dummy_sink_cs_ops = {
 67	.sink_ops = &dummy_sink_ops,
 68};
 69
 70static int dummy_probe(struct platform_device *pdev)
 71{
 72	struct device *dev = &pdev->dev;
 73	struct device_node *node = dev->of_node;
 74	struct coresight_platform_data *pdata;
 75	struct dummy_drvdata *drvdata;
 76	struct coresight_desc desc = { 0 };
 77
 78	if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
 79
 80		desc.name = coresight_alloc_device_name(&source_devs, dev);
 81		if (!desc.name)
 82			return -ENOMEM;
 83
 84		desc.type = CORESIGHT_DEV_TYPE_SOURCE;
 85		desc.subtype.source_subtype =
 86					CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
 87		desc.ops = &dummy_source_cs_ops;
 88	} else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) {
 89		desc.name = coresight_alloc_device_name(&sink_devs, dev);
 90		if (!desc.name)
 91			return -ENOMEM;
 92
 93		desc.type = CORESIGHT_DEV_TYPE_SINK;
 94		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_DUMMY;
 95		desc.ops = &dummy_sink_cs_ops;
 96	} else {
 97		dev_err(dev, "Device type not set\n");
 98		return -EINVAL;
 99	}
100
101	pdata = coresight_get_platform_data(dev);
102	if (IS_ERR(pdata))
103		return PTR_ERR(pdata);
104	pdev->dev.platform_data = pdata;
105
106	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
107	if (!drvdata)
108		return -ENOMEM;
109
110	drvdata->dev = &pdev->dev;
111	platform_set_drvdata(pdev, drvdata);
112
113	desc.pdata = pdev->dev.platform_data;
114	desc.dev = &pdev->dev;
115	drvdata->csdev = coresight_register(&desc);
116	if (IS_ERR(drvdata->csdev))
117		return PTR_ERR(drvdata->csdev);
118
119	pm_runtime_enable(dev);
120	dev_dbg(dev, "Dummy device initialized\n");
121
122	return 0;
123}
124
125static void dummy_remove(struct platform_device *pdev)
126{
127	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
128	struct device *dev = &pdev->dev;
129
130	pm_runtime_disable(dev);
131	coresight_unregister(drvdata->csdev);
132}
133
134static const struct of_device_id dummy_match[] = {
135	{.compatible = "arm,coresight-dummy-source"},
136	{.compatible = "arm,coresight-dummy-sink"},
137	{},
138};
139
140static struct platform_driver dummy_driver = {
141	.probe	= dummy_probe,
142	.remove_new = dummy_remove,
143	.driver	= {
144		.name   = "coresight-dummy",
145		.of_match_table = dummy_match,
146	},
147};
148
149module_platform_driver(dummy_driver);
150
151MODULE_LICENSE("GPL");
152MODULE_DESCRIPTION("CoreSight dummy driver");