diff mbox series

[v6,3/3] coresight: dummy: Add static trace id support for dummy source

Message ID 20241104115604.14522-4-quic_jinlmao@quicinc.com (mailing list archive)
State New
Headers show
Series coresight: Add static trace id support | expand

Commit Message

Mao Jinlong Nov. 4, 2024, 11:56 a.m. UTC 
Some dummy source has static trace id configured in HW and it cannot
be changed via software programming. Configure the trace id in device
tree and reserve the id when device probe.

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
---
 .../sysfs-bus-coresight-devices-dummy-source  | 15 ++++
 drivers/hwtracing/coresight/coresight-dummy.c | 81 ++++++++++++++++---
 2 files changed, 87 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source
new file mode 100644
index 000000000000..c7d975e75d85
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source
@@ -0,0 +1,15 @@ 
+What:		/sys/bus/coresight/devices/dummy_source<N>/enable_source
+Date:		Oct 2024
+KernelVersion:	6.13
+Contact:	Mao Jinlong <quic_jinlmao@quicinc.com>
+Description:	(RW) Enable/disable tracing of dummy source. A sink should be activated
+		before enabling the source. The path of coresight components linking
+		the source to the sink is configured and managed automatically by the
+		coresight framework.
+
+What:		/sys/bus/coresight/devices/dummy_source<N>/traceid
+Date:		Oct 2024
+KernelVersion:	6.13
+Contact:	Mao Jinlong <quic_jinlmao@quicinc.com>
+Description:	(R) Show the trace ID that will appear in the trace stream
+		coming from this trace entity.
diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c
index bb85fa663ffc..666fd36b81b9 100644
--- a/drivers/hwtracing/coresight/coresight-dummy.c
+++ b/drivers/hwtracing/coresight/coresight-dummy.c
@@ -11,10 +11,12 @@ 
 #include <linux/pm_runtime.h>
 
 #include "coresight-priv.h"
+#include "coresight-trace-id.h"
 
 struct dummy_drvdata {
 	struct device			*dev;
 	struct coresight_device		*csdev;
+	u8				traceid;
 };
 
 DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
@@ -72,6 +74,32 @@  static const struct coresight_ops dummy_sink_cs_ops = {
 	.sink_ops = &dummy_sink_ops,
 };
 
+/* User can get the trace id of dummy source from this node. */
+static ssize_t traceid_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	unsigned long val;
+	struct dummy_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	val = drvdata->traceid;
+	return sysfs_emit(buf, "%#lx\n", val);
+}
+static DEVICE_ATTR_RO(traceid);
+
+static struct attribute *coresight_dummy_attrs[] = {
+	&dev_attr_traceid.attr,
+	NULL,
+};
+
+static const struct attribute_group coresight_dummy_group = {
+	.attrs = coresight_dummy_attrs,
+};
+
+static const struct attribute_group *coresight_dummy_groups[] = {
+	&coresight_dummy_group,
+	NULL,
+};
+
 static int dummy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -79,6 +107,11 @@  static int dummy_probe(struct platform_device *pdev)
 	struct coresight_platform_data *pdata;
 	struct dummy_drvdata *drvdata;
 	struct coresight_desc desc = { 0 };
+	int ret = 0, trace_id = 0;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
 
 	if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
 
@@ -90,6 +123,26 @@  static int dummy_probe(struct platform_device *pdev)
 		desc.subtype.source_subtype =
 					CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS;
 		desc.ops = &dummy_source_cs_ops;
+		desc.groups = coresight_dummy_groups;
+
+		ret = coresight_get_static_trace_id(dev, &trace_id);
+		if (!ret) {
+			/* Get the static id if id is set in device tree. */
+			ret = coresight_trace_id_get_static_system_id(trace_id);
+			if (ret < 0) {
+				dev_err(dev, "Fail to get static id.\n");
+				return -EBUSY;
+			}
+		} else {
+			/* Get next available id if id is not set in device tree. */
+			trace_id = coresight_trace_id_get_system_id();
+			if (trace_id < 0) {
+				ret = trace_id;
+				return ret;
+			}
+		}
+		drvdata->traceid = (u8)trace_id;
+
 	} else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) {
 		desc.name = coresight_alloc_device_name(&sink_devs, dev);
 		if (!desc.name)
@@ -104,27 +157,35 @@  static int dummy_probe(struct platform_device *pdev)
 	}
 
 	pdata = coresight_get_platform_data(dev);
-	if (IS_ERR(pdata))
-		return PTR_ERR(pdata);
+	if (IS_ERR(pdata)) {
+		ret = PTR_ERR(pdata);
+		goto free_id;
+	}
 	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);
 
 	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);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto free_id;
+	}
 
 	pm_runtime_enable(dev);
 	dev_dbg(dev, "Dummy device initialized\n");
 
-	return 0;
+	ret = 0;
+	goto out;
+
+free_id:
+	if (IS_VALID_CS_TRACE_ID(drvdata->traceid))
+		coresight_trace_id_put_system_id(drvdata->traceid);
+
+out:
+	return ret;
 }
 
 static void dummy_remove(struct platform_device *pdev)
@@ -132,6 +193,8 @@  static void dummy_remove(struct platform_device *pdev)
 	struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
 	struct device *dev = &pdev->dev;
 
+	if (IS_VALID_CS_TRACE_ID(drvdata->traceid))
+		coresight_trace_id_put_system_id(drvdata->traceid);
 	pm_runtime_disable(dev);
 	coresight_unregister(drvdata->csdev);
 }