coresight: Add snapshot of Coresight dummy driver

Add snapshot for coresight dummy driver from msm-4.19
commit 64be469bda3ae ("power: smb1390-psy: Configure IREV
and main's ICL to prevent IREV condition").
Make necessary change to adopt coresight framework change.

Change-Id: I4c40a64604dc7adc0c9a2c9f9db9ec74232702a2
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>

drivers/hwtracing/coresight/Kconfig

@@ -145,6 +145,14 @@ config CORESIGHT_CSR
 	  Those configuration registers can be used to control, various
 	  coresight configurations.
 
+config CORESIGHT_DUMMY
+	bool "Dummy driver support"
+	help
+	  Enables support for dummy driver. Dummy driver can be used for
+	  CoreSight sources/sinks that are owned and configured by some
+	  other subsystem and use Linux drivers to configure rest of trace
+	  path.
+
 config CORESIGHT_TGU
 	bool "CoreSight Trigger Generation Unit driver"
 	help

drivers/hwtracing/coresight/Makefile

@@ -19,5 +19,6 @@ obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o
 obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o
 obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o
 obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o
+obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
 obj-$(CONFIG_CORESIGHT_CSR) += coresight-csr.o
 obj-$(CONFIG_CORESIGHT_TGU) += coresight-tgu.o

drivers/hwtracing/coresight/coresight-dummy.c

@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016-2017, 2019 The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/coresight.h>
+#include <linux/of.h>
+
+#define DUMMY_TRACE_ID_START	256
+
+struct dummy_drvdata {
+	struct device			*dev;
+	struct coresight_device		*csdev;
+	int				traceid;
+};
+
+DEFINE_CORESIGHT_DEVLIST(dummy_devs, "dummy");
+
+static int dummy_source_enable(struct coresight_device *csdev,
+			       struct perf_event *event, u32 mode)
+{
+	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	dev_info(drvdata->dev, "Dummy source enabled\n");
+
+	return 0;
+}
+
+static void dummy_source_disable(struct coresight_device *csdev,
+				 struct perf_event *event)
+{
+	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	dev_info(drvdata->dev, "Dummy source disabled\n");
+}
+
+static int dummy_sink_enable(struct coresight_device *csdev, u32 mode,
+				void *data)
+{
+	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	dev_info(drvdata->dev, "Dummy sink enabled\n");
+
+	return 0;
+}
+
+static int dummy_sink_disable(struct coresight_device *csdev)
+{
+	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	dev_info(drvdata->dev, "Dummy sink disabled\n");
+
+	return 0;
+}
+
+static int dummy_trace_id(struct coresight_device *csdev)
+{
+	struct dummy_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	return drvdata->traceid;
+}
+
+static const struct coresight_ops_source dummy_source_ops = {
+	.trace_id	= dummy_trace_id,
+	.enable		= dummy_source_enable,
+	.disable	= dummy_source_disable,
+};
+
+static const struct coresight_ops_sink dummy_sink_ops = {
+	.enable		= dummy_sink_enable,
+	.disable	= dummy_sink_disable,
+};
+
+static const struct coresight_ops dummy_cs_ops = {
+	.source_ops	= &dummy_source_ops,
+	.sink_ops	= &dummy_sink_ops,
+};
+
+static int dummy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct coresight_platform_data *pdata;
+	struct dummy_drvdata *drvdata;
+	struct coresight_desc desc = { 0 };
+	static int traceid = DUMMY_TRACE_ID_START;
+
+	desc.name = coresight_alloc_device_name(&dummy_devs, dev);
+	if (!desc.name)
+		return -ENOMEM;
+	pdata = coresight_get_platform_data(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+	pdev->dev.platform_data = pdata;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	drvdata->traceid = traceid++;
+
+	if (of_property_read_bool(pdev->dev.of_node, "qcom,dummy-source")) {
+		desc.type = CORESIGHT_DEV_TYPE_SOURCE;
+		desc.subtype.source_subtype =
+					CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
+	} else if (of_property_read_bool(pdev->dev.of_node,
+					 "qcom,dummy-sink")) {
+		desc.type = CORESIGHT_DEV_TYPE_SINK;
+		desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
+	} else {
+		dev_info(dev, "Device type not set\n");
+		return -EINVAL;
+	}
+
+	desc.ops = &dummy_cs_ops;
+	desc.pdata = pdev->dev.platform_data;
+	desc.dev = &pdev->dev;
+	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev))
+		return PTR_ERR(drvdata->csdev);
+
+	dev_info(dev, "Dummy device initialized\n");
+
+	return 0;
+}
+
+static int dummy_remove(struct platform_device *pdev)
+{
+	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
+static const struct of_device_id dummy_match[] = {
+	{.compatible = "qcom,coresight-dummy"},
+	{},
+};
+
+static struct platform_driver dummy_driver = {
+	.probe	= dummy_probe,
+	.remove	= dummy_remove,
+	.driver	= {
+		.name   = "coresight-dummy",
+		.of_match_table = dummy_match,
+	},
+};
+
+int __init dummy_init(void)
+{
+	return platform_driver_register(&dummy_driver);
+}
+module_init(dummy_init);
+
+void __exit dummy_exit(void)
+{
+	platform_driver_unregister(&dummy_driver);
+}
+module_exit(dummy_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("CoreSight dummy source driver");