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                                __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
  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
  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
  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
  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
 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_new = 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");