[PATCH v7 2/5] coresight: tnoc: Bind Aggregator TNOC on the platform bus

[Jie Gan <jie.gan@oss.qualcomm.com>]

The Aggregator TNOC is bound as an AMBA device through the
"qcom,coresight-tnoc", "arm,primecell" compatible. The AMBA bus reads the
peripheral and component ID registers to identify and probe the device.
Although the Aggregator TNOC exposes the CID registers, the Component ID
value returned by the hardware is 0x00000000 instead of a valid AMBA
Component ID, so the AMBA match 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 component-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.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Jie Gan <jie.gan@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 a0ab99df5db1..4b46ce995862 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"))
 		return 0;
 
 	atid = coresight_trace_id_get_system_id();
@@ -276,7 +276,7 @@ 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;
@@ -293,7 +293,7 @@ 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);
 
@@ -307,10 +307,12 @@ static void itnoc_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&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);
 
@@ -319,7 +321,7 @@ 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);
 
@@ -327,35 +329,36 @@ 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