[PATCH v5 2/5] coresight: tnoc: Bind Aggregator TNOC on the platform bus

[Jie Gan]

The Aggregator TNOC is bound as an AMBA device through the
"qcom,coresight-tnoc", "arm,primecell" compatible. Binding on the AMBA
bus requires the peripheral to expose valid CoreSight peripheral and
component ID registers, which the AMBA bus reads to match and probe the
device. The Aggregator TNOC does not implement these ID registers, so
AMBA probing fails and the device never comes up.

Bind the Aggregator TNOC on the platform bus instead, where the device
is matched by its compatible string and no peripheral-ID probing is
performed. Add "qcom,coresight-tnoc" to the platform driver's match
table, and rename the platform driver and its callbacks from the
"itnoc"-specific names to generic "tnoc" names, since the driver now
serves both the Interconnect and Aggregator TNOC. Update the platform
driver name to "coresight-tnoc" accordingly.

The ATID-unsupported handling keyed off dev_is_amba(), which disabled
ATID allocation for every platform-bus device. With the Aggregator TNOC
now on the platform bus, that check would wrongly disable its ATID, even
though the Aggregator TNOC owns the ATID that tags the whole aggregation
path. The Interconnect TNOC aggregates trace within its subsystem but
carries no ATID of its own, because the downstream Aggregator TNOC
already owns the ATID for the path. So base the check on the
"qcom,coresight-itnoc" compatible and let every other form allocate a
trace ID.

Signed-off-by: Jie Gan <jie.gan at oss.qualcomm.com>
---
 drivers/hwtracing/coresight/coresight-tnoc.c | 37 +++++++++++++++-------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index 9e8de4323d28..737cc802aefe 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -130,7 +130,7 @@ static int trace_noc_init_default_data(struct trace_noc_drvdata *drvdata)
 {
 	int atid;
 
-	if (!dev_is_amba(drvdata->dev)) {
+	if (of_device_is_compatible(drvdata->dev->of_node, "qcom,coresight-itnoc")) {
 		drvdata->atid = -EOPNOTSUPP;
 		return 0;
 	}
@@ -278,7 +278,7 @@ static struct amba_driver trace_noc_driver = {
 	.id_table	= trace_noc_ids,
 };
 
-static int itnoc_probe(struct platform_device *pdev)
+static int tnoc_platform_probe(struct platform_device *pdev)
 {
 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	int ret;
@@ -295,16 +295,18 @@ static int itnoc_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static void itnoc_remove(struct platform_device *pdev)
+static void tnoc_platform_remove(struct platform_device *pdev)
 {
 	struct trace_noc_drvdata *drvdata = platform_get_drvdata(pdev);
 
 	coresight_unregister(drvdata->csdev);
 	pm_runtime_disable(&pdev->dev);
+	if (drvdata->atid > 0)
+		coresight_trace_id_put_system_id(drvdata->atid);
 }
 
 #ifdef CONFIG_PM
-static int itnoc_runtime_suspend(struct device *dev)
+static int tnoc_runtime_suspend(struct device *dev)
 {
 	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
 
@@ -313,7 +315,7 @@ static int itnoc_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int itnoc_runtime_resume(struct device *dev)
+static int tnoc_runtime_resume(struct device *dev)
 {
 	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
 
@@ -321,35 +323,36 @@ static int itnoc_runtime_resume(struct device *dev)
 }
 #endif
 
-static const struct dev_pm_ops itnoc_dev_pm_ops = {
-	SET_RUNTIME_PM_OPS(itnoc_runtime_suspend, itnoc_runtime_resume, NULL)
+static const struct dev_pm_ops tnoc_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(tnoc_runtime_suspend, tnoc_runtime_resume, NULL)
 };
 
-static const struct of_device_id itnoc_of_match[] = {
+static const struct of_device_id tnoc_of_match[] = {
 	{ .compatible = "qcom,coresight-itnoc" },
+	{ .compatible = "qcom,coresight-tnoc" },
 	{}
 };
-MODULE_DEVICE_TABLE(of, itnoc_of_match);
+MODULE_DEVICE_TABLE(of, tnoc_of_match);
 
-static struct platform_driver itnoc_driver = {
-	.probe = itnoc_probe,
-	.remove = itnoc_remove,
+static struct platform_driver tnoc_platform_driver = {
+	.probe = tnoc_platform_probe,
+	.remove = tnoc_platform_remove,
 	.driver = {
-		.name = "coresight-itnoc",
-		.of_match_table = itnoc_of_match,
+		.name = "coresight-tnoc",
+		.of_match_table = tnoc_of_match,
 		.suppress_bind_attrs = true,
-		.pm = &itnoc_dev_pm_ops,
+		.pm = &tnoc_dev_pm_ops,
 	},
 };
 
 static int __init tnoc_init(void)
 {
-	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver);
+	return coresight_init_driver("tnoc", &trace_noc_driver, &tnoc_platform_driver);
 }
 
 static void __exit tnoc_exit(void)
 {
-	coresight_remove_driver(&trace_noc_driver, &itnoc_driver);
+	coresight_remove_driver(&trace_noc_driver, &tnoc_platform_driver);
 }
 module_init(tnoc_init);
 module_exit(tnoc_exit);

-- 
2.34.1