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"); 158