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
15 struct dummy_drvdata {
16 struct device *dev;
17 struct coresight_device *csdev;
18 };
19
20 DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
21 DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");
22
dummy_source_enable(struct coresight_device * csdev,struct perf_event * event,enum cs_mode mode,__maybe_unused struct coresight_trace_id_map * id_map)23 static 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
dummy_source_disable(struct coresight_device * csdev,struct perf_event * event)35 static 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
dummy_sink_enable(struct coresight_device * csdev,enum cs_mode mode,void * data)42 static 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
dummy_sink_disable(struct coresight_device * csdev)50 static 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
57 static const struct coresight_ops_source dummy_source_ops = {
58 .enable = dummy_source_enable,
59 .disable = dummy_source_disable,
60 };
61
62 static const struct coresight_ops dummy_source_cs_ops = {
63 .source_ops = &dummy_source_ops,
64 };
65
66 static const struct coresight_ops_sink dummy_sink_ops = {
67 .enable = dummy_sink_enable,
68 .disable = dummy_sink_disable,
69 };
70
71 static const struct coresight_ops dummy_sink_cs_ops = {
72 .sink_ops = &dummy_sink_ops,
73 };
74
dummy_probe(struct platform_device * pdev)75 static 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
dummy_remove(struct platform_device * pdev)130 static 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
139 static const struct of_device_id dummy_match[] = {
140 {.compatible = "arm,coresight-dummy-source"},
141 {.compatible = "arm,coresight-dummy-sink"},
142 {},
143 };
144
145 static 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
154 module_platform_driver(dummy_driver);
155
156 MODULE_LICENSE("GPL");
157 MODULE_DESCRIPTION("CoreSight dummy driver");
158