[PATCH v4 2/3] coresight-tnoc: add platform driver to support Interconnect TNOC

[Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>]

This patch adds platform driver support for the CoreSight Interconnect
TNOC, Interconnect TNOC is a CoreSight link that forwards trace data
from a subsystem to the Aggregator TNOC. Compared to Aggregator TNOC,
it does not have aggregation and ATID functionality.

Key changes:
- Add platform driver `coresight-itnoc` with device tree match support.
- Refactor probe logic into a common `_tnoc_probe()` function.
- Conditionally initialize ATID only for AMBA-based TNOC blocks.

Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
---
 drivers/hwtracing/coresight/coresight-tnoc.c | 113 ++++++++++++++++++++++++---
 1 file changed, 102 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index d542df46ea39314605290311f683010337bfd4bd..5be882300d79bc0173aa6a19d7da1d48c4aaca9c 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -34,6 +34,7 @@
  * @base:      memory mapped base address for this component.
  * @dev:       device node for trace_noc_drvdata.
  * @csdev:     component vitals needed by the framework.
+ * @pclk:	APB clock if present, otherwise NULL
  * @spinlock:  serialize enable/disable operation.
  * @atid:      id for the trace packet.
  */
@@ -41,8 +42,9 @@ struct trace_noc_drvdata {
 	void __iomem		*base;
 	struct device		*dev;
 	struct coresight_device	*csdev;
+	struct clk		*pclk;
 	spinlock_t		spinlock;
-	u32			atid;
+	int			atid;
 };
 
 DEFINE_CORESIGHT_DEVLIST(trace_noc_devs, "traceNoc");
@@ -51,6 +53,12 @@ static void trace_noc_enable_hw(struct trace_noc_drvdata *drvdata)
 {
 	u32 val;
 
+	/* No valid ATID, simply enable the unit */
+	if (drvdata->atid == -EOPNOTSUPP) {
+		writel(TRACE_NOC_CTRL_PORTEN, drvdata->base + TRACE_NOC_CTRL);
+		return;
+	}
+
 	/* Set ATID */
 	writel_relaxed(drvdata->atid, drvdata->base + TRACE_NOC_XLD);
 
@@ -124,6 +132,11 @@ static int trace_noc_init_default_data(struct trace_noc_drvdata *drvdata)
 {
 	int atid;
 
+	if (!dev_is_amba(drvdata->dev)) {
+		drvdata->atid = -EOPNOTSUPP;
+		return 0;
+	}
+
 	atid = coresight_trace_id_get_system_id();
 	if (atid < 0)
 		return atid;
@@ -149,8 +162,21 @@ static struct attribute *coresight_tnoc_attrs[] = {
 	NULL,
 };
 
+static umode_t trace_id_is_visible(struct kobject *kobj,
+				   struct attribute *attr, int idx)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	if (attr == &dev_attr_traceid.attr && drvdata->atid < 0)
+		return 0;
+
+	return attr->mode;
+}
+
 static const struct attribute_group coresight_tnoc_group = {
 	.attrs = coresight_tnoc_attrs,
+	.is_visible = trace_id_is_visible,
 };
 
 static const struct attribute_group *coresight_tnoc_groups[] = {
@@ -158,9 +184,8 @@ static const struct attribute_group *coresight_tnoc_groups[] = {
 	NULL,
 };
 
-static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id)
+static int _tnoc_probe(struct device *dev, struct resource *res)
 {
-	struct device *dev = &adev->dev;
 	struct coresight_platform_data *pdata;
 	struct trace_noc_drvdata *drvdata;
 	struct coresight_desc desc = { 0 };
@@ -173,16 +198,20 @@ static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id)
 	pdata = coresight_get_platform_data(dev);
 	if (IS_ERR(pdata))
 		return PTR_ERR(pdata);
-	adev->dev.platform_data = pdata;
+	dev->platform_data = pdata;
 
 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->dev = &adev->dev;
+	drvdata->dev = dev;
 	dev_set_drvdata(dev, drvdata);
 
-	drvdata->base = devm_ioremap_resource(dev, &adev->res);
+	ret = coresight_get_enable_clocks(dev, &drvdata->pclk, NULL);
+	if (ret)
+		return ret;
+
+	drvdata->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(drvdata->base))
 		return PTR_ERR(drvdata->base);
 
@@ -195,20 +224,31 @@ static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id)
 	desc.ops = &trace_noc_cs_ops;
 	desc.type = CORESIGHT_DEV_TYPE_LINK;
 	desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
-	desc.pdata = adev->dev.platform_data;
-	desc.dev = &adev->dev;
+	desc.pdata = pdata;
+	desc.dev = dev;
 	desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
 	desc.groups = coresight_tnoc_groups;
 	drvdata->csdev = coresight_register(&desc);
 	if (IS_ERR(drvdata->csdev)) {
-		coresight_trace_id_put_system_id(drvdata->atid);
+		if (drvdata->atid > 0)
+			coresight_trace_id_put_system_id(drvdata->atid);
 		return PTR_ERR(drvdata->csdev);
 	}
-	pm_runtime_put(&adev->dev);
 
 	return 0;
 }
 
+static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+
+	ret = _tnoc_probe(&adev->dev, &adev->res);
+	if (!ret)
+		pm_runtime_put(&adev->dev);
+
+	return ret;
+}
+
 static void trace_noc_remove(struct amba_device *adev)
 {
 	struct trace_noc_drvdata *drvdata = dev_get_drvdata(&adev->dev);
@@ -236,7 +276,58 @@ static struct amba_driver trace_noc_driver = {
 	.id_table	= trace_noc_ids,
 };
 
-module_amba_driver(trace_noc_driver);
+static int itnoc_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	int ret;
+
+	pm_runtime_get_noresume(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = _tnoc_probe(&pdev->dev, res);
+	pm_runtime_put(&pdev->dev);
+	if (ret)
+		pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static void itnoc_remove(struct platform_device *pdev)
+{
+	struct trace_noc_drvdata *drvdata = platform_get_drvdata(pdev);
+
+	coresight_unregister(drvdata->csdev);
+	pm_runtime_disable(&pdev->dev);
+}
+
+static const struct of_device_id itnoc_of_match[] = {
+	{ .compatible = "qcom,coresight-itnoc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, itnoc_of_match);
+
+static struct platform_driver itnoc_driver = {
+	.probe = itnoc_probe,
+	.remove = itnoc_remove,
+	.driver = {
+		.name = "coresight-itnoc",
+		.of_match_table = itnoc_of_match,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init tnoc_init(void)
+{
+	return coresight_init_driver("tnoc", &trace_noc_driver, &itnoc_driver, THIS_MODULE);
+}
+
+static void __exit tnoc_exit(void)
+{
+	coresight_remove_driver(&trace_noc_driver, &itnoc_driver);
+}
+module_init(tnoc_init);
+module_exit(tnoc_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Trace NOC driver");

-- 
2.34.1