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(device: node, "arm,coresight-dummy-source")) {
79
80 desc.name = coresight_alloc_device_name(devs: &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(device: node, "arm,coresight-dummy-sink")) {
89 desc.name = coresight_alloc_device_name(devs: &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(ptr: pdata))
103 return PTR_ERR(ptr: pdata);
104 pdev->dev.platform_data = pdata;
105
106 drvdata = devm_kzalloc(dev, size: sizeof(*drvdata), GFP_KERNEL);
107 if (!drvdata)
108 return -ENOMEM;
109
110 drvdata->dev = &pdev->dev;
111 platform_set_drvdata(pdev, data: drvdata);
112
113 desc.pdata = pdev->dev.platform_data;
114 desc.dev = &pdev->dev;
115 drvdata->csdev = coresight_register(desc: &desc);
116 if (IS_ERR(ptr: drvdata->csdev))
117 return PTR_ERR(ptr: 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(csdev: 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");
153

source code of linux/drivers/hwtracing/coresight/coresight-dummy.c