drivers/hwtracing/coresight/coresight-dummy.c

   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
  23 static 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
  31 static 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
  37 static 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
  45 static 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
  52 static const struct coresight_ops_source dummy_source_ops = {
  53         .enable = dummy_source_enable,
  54         .disable = dummy_source_disable,
  55 };
  56
  57 static const struct coresight_ops dummy_source_cs_ops = {
  58         .source_ops = &dummy_source_ops,
  59 };
  60
  61 static const struct coresight_ops_sink dummy_sink_ops = {
  62         .enable = dummy_sink_enable,
  63         .disable = dummy_sink_disable,
  64 };
  65
  66 static const struct coresight_ops dummy_sink_cs_ops = {
  67         .sink_ops = &dummy_sink_ops,
  68 };
  69
  70 static 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
 125 static int 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         return 0;
 133 }
 134
 135 static const struct of_device_id dummy_match[] = {
 136         {.compatible = "arm,coresight-dummy-source"},
 137         {.compatible = "arm,coresight-dummy-sink"},
 138         {},
 139 };
 140
 141 static struct platform_driver dummy_driver = {
 142         .probe  = dummy_probe,
 143         .remove = dummy_remove,
 144         .driver = {
 145                 .name   = "coresight-dummy",
 146                 .of_match_table = dummy_match,
 147         },
 148 };
 149
 150 module_platform_driver(dummy_driver);
 151
 152 MODULE_LICENSE("GPL");
 153 MODULE_DESCRIPTION("CoreSight dummy driver");