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 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 } 133 134 static const struct of_device_id dummy_match[] = { 135 {.compatible = "arm,coresight-dummy-source"}, 136 {.compatible = "arm,coresight-dummy-sink"}, 137 {}, 138 }; 139 140 static 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 }; 148 149 module_platform_driver(dummy_driver); 150 151 MODULE_LICENSE("GPL"); 152 MODULE_DESCRIPTION("CoreSight dummy driver"); 153